SOMERVILLE, Mass., April 28, 2022 (GLOBE NEWSWIRE) -- Finch Therapeutics Group, Inc. (“Finch” or “Finch Therapeutics”) (Nasdaq: FNCH), a clinical-stage microbiome therapeutics company leveraging its Human-First Discovery® platform to develop a novel class of orally administered biological drugs, today announced that the U.S. Food and Drug Administration (FDA) has removed the clinical hold on Finch’s investigational new drug (IND) application for CP101. CP101 is the Company’s investigational orally administered microbiome therapeutic which is in late-stage clinical development for the prevention of recurrent C. difficile infection (CDI). The FDA lifted the clinical hold following a review of information Finch provided related to its SARS-CoV-2 screening procedures and associated informed consent language.

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Finch Therapeutics Announces Removal of FDA Clinical Hold on CP101 IND

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Mesoblast Operational and Financial Highlights for Quarter Ended March 31, 2022 Mesoblast Operational and Financial Highlights for Quarter Ended March 31, 2022

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Appendix 4C Quarterly Activity Report

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REGULATED INFORMATION

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Bone Therapeutics announces 2021 full year results

Global News Feed Comments Off on Bone Therapeutics announces 2021 full year results | April 29th, 2022

Basel, 29 April 2022 - Roche (SIX: RO, ROG; OTCQX: RHHBY) today announced new three-year data from the FIREFISH study, including one-year data from the open label extension, reinforcing the long-term efficacy and safety of Evrysdi® (risdiplam) in infants with symptomatic Type 1 spinal muscular atrophy (SMA). The data showed an estimated 91% of infants (n=58) treated with Evrysdi were alive after three years of treatment. The Evrysdi-treated infants continued to improve or maintain motor functions, including the ability to swallow, sit without support, stand with support and walk while holding on, between two and three years of treatment. Without treatment, children with Type 1 SMA are never able to sit without support. The study also showed overall continued reductions in serious adverse events (SAEs) and hospitalisations over time.

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New three-year data for Roche’s Evrysdi (risdiplam) show long-term improvements in survival and motor milestones in babies with Type 1 spinal...

Global News Feed Comments Off on New three-year data for Roche’s Evrysdi (risdiplam) show long-term improvements in survival and motor milestones in babies with Type 1 spinal… | April 29th, 2022

Ad hoc announcement pursuant to Art. 53 LR

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Santhera will Publish its 2021 Annual Report by June 3, 2022, and Hold its Annual General Meeting on June 29, 2022

Global News Feed Comments Off on Santhera will Publish its 2021 Annual Report by June 3, 2022, and Hold its Annual General Meeting on June 29, 2022 | April 29th, 2022

LONDON, April 29, 2022 (GLOBE NEWSWIRE) --      Dear shareholders, friends,

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Letter to shareholders from CLINUVEL’s CEO

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Stem cell transplants can effectively cure a wide range of diseases, from blood cancers to rare genetic disorders. They've been used for decades and are considered standard treatment for certain conditions.

But for a good number of patients, stem cell transplants are out of reach. Drug regimens used to prepare the body for a transplant are toxic and can cause serious side effects. The transplanted cells don't always "engraft," or take root in the bone marrow. Even when they do, patients' disease may linger or recur.

A biotech startup launching Wednesday with $50 million in funding hopes that, by combining cell, antibody and gene editing technologies, at least some of these problems can be overcome. Called Cimeio Therapeutics, the new company is led by a team of pharmaceutical industry veterans and an advisory board filled with scientific luminaries, including immunologist Jeffrey Bluestone and gene editing pioneer Fyodor Urnov.

Cimeio's approach involves "shielding" transplanted cells by genetically editing them in ways that allows paired immunotherapies to be safely used both before and after a transplant.

Thomas Fuchs

Courtesy of Cimeio Therapeutics

"We think that this can really unleash the power of hematopoietic stem cell transplant and make a lot more patients eligible for it," said Thomas Fuchs, Cimeio's CEO and a former Genentech executive.

The "shielding" technology used by Cimeio was developed in Switzerland at the laboratory of Lukas Jeker, a physician-scientist from Basel University Hospital who will join Cimeio as head of gene editing.

Jeker's lab discovered that protein receptors on the surface of cells could be genetically edited in such a way that prevented antibodies from binding to them, while leaving their function intact. In preclinical testing, these edits could cloak, or "shield," the cells from being depleted by antibody drugs and T cell therapies.

The work could have powerful implications for improving stem cell transplant and adoptive cell therapy, according to Fuchs.

Once a stem cell or T cell is shielded, a complementary immunotherapy could be used to either help ready patients for a transplant or to further treat disease afterwards, he said. "Maybe you could give a cycle or two of the paired immunotherapy, implant the shielded cells and then continue to administer the immunotherapy," he added.

If the shielding works as intended, Cimeio could develop treatments for conditioning that are more tolerable than the chemotherapy or radiation-based regimens currently in use. Shielding might also allow existing drugs that target cell proteins on healthy as well as diseased cells to be used more flexibly with transplants, such as to treat residual disease that lingers afterwards.

For example, Cimeio could engineer stem cells that are protected against binding via a protein called CD19 that's often the target for CAR-T therapies that treat lymphoma, but is also found on healthy B cells that help the immune system fight off threats.

"One benefit could be that you could prevent a lifetime of B cell depletion, which happens when you give a CAR-T," said Fuchs.

Alex Mayweg

Courtesy of Cimeio Therapeutics

Cimeio was built from Jeker's lab by Versant Ventures at the company's "Ridgeline" incubator in Basel, which has previously produced companies like Monte Rosa Therapeutics and Black Diamond Therapeutics. The initial $50 million Versant provided will fund Cimeio through next year, said Alex Mayweg, a managing director at the venture firm and a Cimeio board member. Additional investors will be brought on later this year or early next, Mayweg said.

Cimeio will need the money, as its research and development plans are expansive. The company has identified four drug candidates already and envisions a dozen more behind those, said Fuchs. Its research spans blood cancers, rare genetic diseases and autoimmune disorders.

In some cases, Cimeio will develop paired immunotherapies to go with the shielded cells. In others, it will use existing treatments. Three of the first four candidates involve protecting hematopoietic stem cells, while the fourth involves T cells. The company hopes to begin human testing next year.

Cimeio plans to choose gene editing technologies based on the type of alteration it needs to make to shield cells. "Rather than building up an internal editing capability," Mayweg said, "we wanted to stay as flexible as possible."

That might mean partnerships or alliances with other companies, some of which have reached out to Cimeio already, according to Mayweg.

Cimeio is aided by a group of scientific advisers notable for their work in areas the company is focusing on. Urnov, of the University of California, Berkeley, is well known for his research in gene editing using zinc finger nucleases and CRISPR. Bluestone previously led the Parker Institute for Cancer Immunotherapy and is CEO of the cell therapy-focused biotech Sonoma Biotherapeutics.

Suneet Agarwal, a co-program leader of the stem cell transplant center at Boston Children's Cancer and Blood Disorders Center, is also on the advisory board, while Cimeio has a research collaboration in place with Matthew Porteus, a gene editing specialist at Stanford University.

About 20 people currently work at Cimeio directly, a number Fuchs expects will grow as the company's research advances. Another 15 are currently supporting Cimeio from Versant's Ridgeline group.

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Versant-backed startup launches with plans to broaden cell therapy's reach - BioPharma Dive

Bone Marrow Stem Cells Comments Off on Versant-backed startup launches with plans to broaden cell therapy’s reach – BioPharma Dive | April 15th, 2022

ABC24 talked with Randy Hutchinson from the Better Business Bureau of the Mid-South about a lawsuit against one company and what consumers need to watch out for.

MEMPHIS, Tenn. The Federal Trade Commission and Georgia Attorney General have sued the founders of a company they claim has made unsubstantiated claims its stem cell therapy can treat arthritis, joint pain, and other orthopedic ailments.

The company is called Stem Cell Institute of America. It claimed its treatments are comparable to or better than surgery, steroid injections, and painkillers. The FTC said the company charged up to $5,000 per injection. It said a related company taught chiropractors and other healthcare professionals how to offer stem cell therapy.

ABC24 talked with Randy Hutchinson from the Better Business Bureau of the Mid-South about the claims and what consumers need to watch out for.

So what are the facts about stem cells?

They're sometimes called the body's "master cells" because they develop into blood, brain, bones, and other organs.

Stem cells from bone marrow or blood are used to treat certain kinds of cancer and disorders of the blood and immune system. But other uses have not been properly studied and approved.

The FDA cites these potential risks from unproven treatments:

There could be safety risks even using a persons own stem cells.

Other claims by some companies

The FTC has also looked into companies claiming their stem cell therapies can treat Parkinson's, multiple sclerosis, COVID, and a host of other ailments. They're sometimes referred to as "regenerative medicine."

So what do consumers need to do?

Take miracle health care claims with a grain of salt.

Check out a company and treatment online using terms like "complaints," "scam" and "reviews."

Consult your own health care provider before using any product or treatment.

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Be wary of companies offering stem cell therapy for arthritis, joint pain, COVID, and more. Heres why - WATN - Local 24

Bone Marrow Stem Cells Comments Off on Be wary of companies offering stem cell therapy for arthritis, joint pain, COVID, and more. Heres why – WATN – Local 24 | April 15th, 2022

Marc Howard was diagnosed with multiple myeloma. He will receive a transplant using his own cells later this year.

COLUMBUS, Ohio It all started with back pain that seemed to be progressively getting worse.

My back, the structure of my body, was like starting to deteriorate, and I could tell, he said. I'm tall, so when I started to lean over, and the pain and things of that nature, I'm like, yo, something's going on.

His longtime love Sonia Grant noticed, too. And she was right there to encourage him to get it checked.

When he did, doctors found holes in his spine where his bone had deteriorated. He had a vertebroplasty procedure to have those holes filled with bone cement. But that was not the end of his journey. In fact, it was really only the beginning.

After the surgery, he was okay for about a month, then I saw him (leaning) over again, and he couldnt get off the bed one day, Grant said. I said, uh uh, were going back up there (to the hospital). Theres something wrong.

And something was. Howard was diagnosed with multiple myeloma, a cancer that forms in the plasma cells.

I dont want to be the woe is me, Howard said. I want to be the success story for somebody, for the world to look at, like, that man went through a situation, and he made it.

And hes making it so far, with the help of Grant. Hes been doing weekly chemotherapy treatments and taking daily medication. Meanwhile, Grant is making sure hes eating his fruits and veggies and drinking plenty of water, too.

If youre not up to the challenge, I will help you get there, I will, Grant said. Because failure is just not a thing when it comes to fighting something like cancer. You gotta fight, you just gotta fight.

This fight will culminate with a major procedure later this fall via OhioHealths new Blood and Marrow Transplant Program. Howard will be one of the first patients to receive an autologous stem cell transplant, meaning the procedure will use his own cells.

Dr. Yvonne Efebera, the medical director for the program, explains this process is different than a procedure using donor cells.

BMT, blood and marrow transplant, is a process where, certain diseases require this, where non-functioning, deficient bone marrow or cancer cells are eliminated by giving high-dose chemotherapy, with or without radiation, and then replaced by new, healthy cells, Dr. Efebera said.

Shes been treating Howard throughout this process and points out that this is one of the benefits of the new program. Before, patients who needed transplants would have to be sent to other healthcare systems. Now, they can go from start to finish with the same clinical team.

Marc always wanted to be the first, she joked. Hes anxious to have his stem cells to be the first collected and the first admitted.

Both Howard and Grant are up to the challenge.

Its a battle, Grant said. Were halfway through the battle, and so, were going to get all the way to the end of the battle. Bruised, not broken. But were in the battle. But were going to get through it.

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Columbus man to be one of first to receive transplant via new OhioHealth program - 10TV

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Investigators uncovered potential mechanisms of resistance to CD19-directed CAR T-cell therapy in patients with pediatric acute lymphoblastic leukemia.

Bone marrow samples from a trial examining CD19-directed CAR T-cell therapy helped investigators identify epigenetic biomarkers predicting resistance to therapy in pediatric acute lymphoblastic leukemia (ALL), according to a presentation from the 2022 American Association for Cancer Research (AACR) Annual Meeting.1

Investigators observed 3 key features of leukemia cells that do not respond to CAR T-cell therapy: hypermethylation of DNA, a stem cell-like phenotype and inherent plasticity, and decreased antigen presentation. These are independent of CD19 status and leukemia subtype, indicating a new predictive biomarker.

Whats most important about this is we can detect it prior to therapy in patient samples, so this highlights its potential as a biomarker for response, Katherine E. Masih, BS, an NIH-Cambridge scholar in the Genetics Branch, Center for Cancer Research at the National Cancer Institute, said in a press conference. We hope that eventually this can improve patient selection and eligibility for CD19 CAR T-cell therapy.

CD19 is a common target of CAR T cells, and resistance to treatment can occur even if patients continue to show CD19 expression. The investigators explored primary non-response (PNR) to CAR T-cell therapy, which occurs in 10% to 20% of patients and whose causes are not fully understood. Known reasons for non-response to CAR T cells include collection of dysfunctional T cells and decreased death cell receptors on the cell surface.2,3

The investigators used bone marrow samples from 14 participants in the PLAT-02 trial (NCT02028455) of CD19-directed CAR T-cell therapy for relapsed/refractory pediatric ALL.1 These samples included those of 7 patients who had a complete response to therapy and 7 who had no response. Non-response was defined as not achieving and maintaining minimal residual disease negativity at 63 days.

A multiomic analysis of the bone marrow included whole-exome sequencing, RNA sequencing of the bulk cells, single-cell RNA sequencing, array-based methylation analysis, and ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing).

In patients who went on to have PNR, investigators discovered epigenetic markers including 238 regions of hypermethylated DNA, which is associated with inactivated genes (P = 8.15 10-25). These regions are known to be activated in stem cells.

The ATAC-seq analysis showed increased accessibility of chromatin at regions linked to stem cell proliferation (normalized enrichment score [NES] = 2.31; P < .0001) and cell cycling (NES = 2.27; P < .0001), indicating inherent plasticity that may allow leukemia cells to adapt to resist CAR T-cell therapy.

Investigators found that the epigenetic differences did not lead to differences in phenotype of B cells between primary sensitive and PNR patients. However, PNR cells did show an increase in regions associated with hematopoietic stem cells and myeloid and lymphoid progenitors. In addition, investigators observed decreased antigen presentation and processing that could lead to lack of response in cells that still express CD19 (P = .0001).

These factors characterized a potential novel biomarker associated with PNR that investigators named Stem-Cell Epigenome with Multi-Lineage Potential (SCE-MLP). Masih acknowledged that the sample size of 14 patients was small and more research on SCE-MLPs link to PNR is needed. We would love to see this validated in a larger cohort with more cases of PNR that exist around the country, she said.

Another potential use of SCE-MLP could be to find ways to overcome resistance to CAR T-cell therapy by combining it with targeted therapies that disrupt these epigenetic factors for resistance.

Currently, the investigators hope that this research will be used to shape patient selection for CAR T-cell therapy and alternative therapies.

If we can reliably identify responders, perhaps through screening for SCE-MLP, we can prioritize less toxic targeted therapies for our patients and overall improve outcomes for children with this devastating disease, Masih said.

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Molecular Characteristics of Resistance to CD19-Directed CAR T Cells Revealed in Pediatric ALL - Cancer Network

Bone Marrow Stem Cells Comments Off on Molecular Characteristics of Resistance to CD19-Directed CAR T Cells Revealed in Pediatric ALL – Cancer Network | April 15th, 2022

Photo: Contributed

Salny Ehman, left, and Tom Ellison, the man whose life she saved through a bone marrow donation.

Penticton resident Salny Ehman saved a complete stranger's life, and hopes to inspire others to do the same.

Ehman, now 35, signed up to be a bone marrow donor at the age of 19, after watching her grandmother's sibling go through leukemia.

"She has a whole bunch of siblings, and one of them had blood cancer, and only she was a match. And the math of that blew me away, how likely is it to have a close relative that can help?" Ehman said.

"If it's that unlikely to have a match when you have that many siblings, then people need to sign up."

Ehman did just that. She registered with Canadian Blood Services, and a few months later, got a call that she was a match with an anonymous recipient signed up through an American service, fighting cancer and in need of bone marrow stem cells.

Despite not knowing who she was donating to, Ehman underwent the donation procedure, and then one year later, did the same thing again after learning the recipient's body had been rejecting the donated cells.

"One year after the second donation, we were both allowed to say yes, we would like to know the other person. And we both said yes, but I was living in Nova Scotia at the time," Ehman said, having learned her stem cell recipient, Tom Allison, lived in Seattle.

"The only information given to me about [my donor] was it was a 19 year old girl from Nova Scotia. And I thought, what's a 19 year old girl doing on a bone marrow registry for?" Allison said.

"Neither one of my boys were matches, and neither one of my brothers. So this seemed just a million to one chance for somebody out there with a match that's no relation to me."

Allison and Ehman ultimately got in touch and kept in touch for more than a decade.

"We would write each other letters over the years, and little postcards," Ehman said.

"And then I moved here [to Penticton] two years ago. So as soon as I moved here, I was like, 'Wow, I'm so close.' Just a quick drive, like three and a half hours away."

She and Allison, who is now in his 60s and healthy post-cancer, met up in person recently, and Ehman was thrilled to see him thriving thanks to her donation.

"Second to my daughters, [donating] was the best, best experience in my entire life. And to know that he was out there, and spending time with his family, his grandchildren, it really meant a lot. And it showed me what I was capable of," Ehman said.

She and Allison remain good friends, and she urges anyone who can help to either sign up to be a donor, or if they can't participate in that way, give financially to Canadian Blood Services.

"There's lots of opportunities to help that cause," she said.

Find out more about Canadian Blood Services and how you can help here, and learn how you can be the match that saves someone's life here.

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Penticton woman donated bone marrow to save stranger's life, urges others to do the same - Penticton News - Castanet.net

Bone Marrow Stem Cells Comments Off on Penticton woman donated bone marrow to save stranger’s life, urges others to do the same – Penticton News – Castanet.net | April 15th, 2022

This article was originally published here

Mol Biotechnol. 2022 Apr 9. doi: 10.1007/s12033-022-00487-z. Online ahead of print.

ABSTRACT

Exosomes-related microRNAs (miRNAs) have been considered to be the significant biomarkers contributing to the development of atrial fibrillation (AF). We observed the implicit mechanism of exosomes-miR-148a derived from bone marrow mesenchymal stem cells (BMSCs) in AF. The AF cell and mice models were established firstly. QRT-PCR and Western blot analysis were applied to detect the expression of miR-148a, SPARC-associated modular calcium-binding protein 2 (SMOC2), Bcl-2, Bax, and caspase-3. BMSCs were separated from healthy mice and exosomes were obtained from BMSCs. BMSCs were transfected with mimics and inhibitor, and HL-1 cells were treated with mimics and pcDNA3.1. MTT assay were used to detect cell viability of cells. Flow cytometric analysis and TUNEL analysis were used for detecting cell apoptosis of cells. In our study, exosomes derived from BMSCs inhibited the development of AF, and miR-148a acted a vital role in this segment. SMOC2 was a target gene of miR-148a and promoted apoptosis of HL-1 cells. Additionally, miR-148a mimics decreased cellular apoptosis, eliminated SMOC2 expression, and elevated Bcl-2 expression in AF-treated cells. Collectively, miR-148a overexpressed in BMSC-exosomes restrained cardiomyocytes apoptosis by inhibiting SMOC2.

PMID:35397056 | DOI:10.1007/s12033-022-00487-z

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microRNA-148a in Exosomes Derived from Bone Marrow Mesenchymal Stem Cells Alleviates Cardiomyocyte Apoptosis in Atrial Fibrillation by Inhibiting...

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Three children are fighting for their lives and require stem cell transplants to cure their blood cancers and disorders.

Rayaan (four months), Emily (five months) and Neo (7) all share one commonality: being diagnosed with life-threatening blood diseases. They are waiting on blood stem cell transplantations from unrelated donors.

Between 800 and 1 000 children in South Africa are diagnosed with cancer annually.

However, this number does not account for the almost 50% of cases of childhood cancer that are never diagnosed, due to a lack of knowledge regarding the disease and how it presents in children.

Because children still experience growth spurts within a short space of time, this may cause blood cancer and disorders to spread quicker and more aggressively. Therefore, diseases affecting young children are those most often occurring in the developing cells, such as bone marrow, blood, kidneys and nervous system tissues.

Rayaan, Emily and Neos families lives have been turned upside down by blood cancer and disorders.

Rayaan was diagnosed with life-threatening acute myeloid leukaemia when he was just eight weeks old. AML usually requires immediate treatment and for Rayaan, bone marrow or blood stem cell transplant is his only chance of a cure.

Without a successful transplant, Rayaan will have to endure continued chemotherapy and isolation, which will expose him to the terminal effects of infection. Rayaan is now in search of an unrelated matching donor, but the low representation of diverse stem cell donors across the country and in the global registry hampers the chances of saving this courageous baby.

Arlene said watching her son endure this pain is heartbreaking and there have been some very dark days. At one point, he had to be resuscitated after a spinal lumbar puncture, but their courageous little fighter battled on and still wakes up every day with a smile on his face.

Please help my baby to live. He is just too little to suffer like this. Dont delay, you could be his perfect match, Arlene added.

Meanwhile, five-month-old Emily from Johannesburg has been battling a blood disorder following her diagnosis in November at only three months. She was diagnosed with juvenile myelomonocytic leukaemia (JMML) and is undergoing treatment, hoping a stem cell transplant will be performed soon.

As in Rayaans case, Emilys best chance at survival is a blood stem cell transplant. Dr Theo Gerdener, a clinical haematologist at Albert Alberts Stem Cell Transplant Centre and medical director at DKMS Africa, said:

JMML, which is especially prevalent in young children, is a rare cancer of the blood and occurs when white blood cells, known as monocytes and myelocytes, mature abnormally. This cancer can occur spontaneously or, sometimes, is linked to other genetic disorders.

Leukaemia affects white blood cells and bone marrow, and alarmingly, childhood leukaemia accounts for around 25% of all cancer in children. With proper diagnosis and management, including stem cell transplantation, childhood leukaemia can be cured in 85% to 90% of patients.

According to Natalie, Emilys mother, her daughter has already endured multiple blood and platelet transfusions, frequent injections and other medication, lengthy hospital stays, including isolation and ICU admission, as well as surgery to insert a port in her chest for intravenous administration.

Her parents desperately hope to find a stem cell donor match through DKMS global stem cell registry and donor centre to provide them with this one in 100 000 chance.

Were keeping positive and are hoping a match will be found for Emily. We hope she grows up, has a normal childhood and becomes a beautiful, bright young lady, said Natalie.

Neo was diagnosed with Fanconi anaemia in April 2019 at only four years old. A couple of years earlier, his older sister, who was also diagnosed with the same blood disorder, received a stem cell donor transplant, giving her a second chance at life.

Their dad, Phoebus, recalls the late-night rushes to the hospital, overnight stays and time away from work, as both parents grappled with the unusual, but persistent symptoms in their child, as Neo endured uncontrollable nosebleeds, debilitating fatigue, prominent bruising and innumerable fevers and infections owing to his compromised immune system.

Neo is transfusion-dependent and receiving steroid treatment, among other things. He is also searching for his second chance at life through an unrelated donor match to provide him with a life-saving blood stem cell transplant.

A donor with the same ethnic background as a patient may be a better match than one who comes from an entirely different background.

Globally, there are a low number of registered donors among the black, Indian and mixed-ethnic populations, meaning the pool of prospective matches is significantly lower.

For patients like Neo, a substantial increase in the registration of black donors will directly impact his chances of a successful transplant from a matched donor.

Neos family has thrown its support behind DKMS Africa to champion the cause of education and awareness around blood diseases.

Also Read:Young couple says I do with the help of generous donors

People need to be aware of these medical conditions and empower themselves with the knowledge. Some people and organisations are there to help. People should not be afraid to reach out, said Phoebus.

If you are in good health and between the ages of 18 and 55 and considering joining the registry, visit http://www.dkms-africa.org or call 0800 12 10 82, weekdays between 08:30 and 16:30.

Once you have registered online, a swab kit is sent to you via courier and then collected when you have completed the process (at no cost to you). Take action, save a life!

Also Read:Become an organ donor and help save a life

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Donors needed to save young lives - Benoni City Times

Bone Marrow Stem Cells Comments Off on Donors needed to save young lives – Benoni City Times | April 15th, 2022

AUSTIN, Texas, April 13, 2022 /PRNewswire/ -- Direct Biologics, an innovative biotechnology company with a groundbreaking extracellular vesicle (EV) platform drug technology, announced that the U.S. Food and Drug Administration (FDA) has awarded their EV drug product ExoFlo with a Regenerative Medicine Advanced Therapy (RMAT) designation for the treatment of Acute Respiratory Distress Syndrome (ARDS) associated with COVID-19. The RMAT program is designed to expedite the approval of promising regenerative medical products in the US that demonstrate clinical evidence indicating the ability to address an unmet medical need for a serious life-threatening disease or condition. Under the RMAT designation, the FDA provides intensive guidance on drug development and post-market requirements through early and frequent interactions. Additionally, an RMAT confers eligibility for accelerated approval and priority review of biologics licensing applications (BLA).

"After intensively reviewing our preclinical data, manufacturing processes, and clinical data from our Phase II multicenter, double blinded, placebo controlled randomized clinical trial, the FDA has recognized ExoFlo as a lifesaving treatment for patients suffering from Acute Respiratory Distress Syndrome (ARDS) due to severe or critical COVID-19," said Mark Adams, Chief Executive Officer. "The additional attention, resources, and regulatory benefits provided by an RMAT designation demonstrate that the FDA views ExoFlo as a product that can significantly enhance the standard of care for the thousands still dying from ARDS every week in the US," he said.

"We are very pleased that the FDA has recognized the lifesaving potential of our platform drug technology ExoFlo. The RMAT has provided a pathway to expedite our drug development to achieve a BLA in the shortest possible time," said Joe Schmidt, President. "I am very proud of our team. Everyone has been working around the clock for years in our mission to save human lives taken by a disease that lacks treatment options, both in the US and abroad. We are grateful for the opportunity to accelerate development of ExoFlo under the RMAT designation as it leads us closer to our goal of bringing our life saving drug to patients who desperately need it."

ExoFlo is an acellular human bone marrow mesenchymal stem cell (MSC) derived extracellular vesicle (EV) product. These nanosized EVs deliver thousands of signals in the form of regulatory proteins, microRNA, and messenger RNA to cells in the body, harnessing the anti-inflammatory and regenerative properties of bone marrow MSCs without the cost, complexity and limitations of scalability associated with MSC transplantation. ExoFlo is produced using a proprietary EV platform technology by Direct Biologics, LLC.

Physicians can learn more and may request information on becoming a study site at clinicaltrials.gov. For more information on Direct Biologics and regenerative medicine, visit: https://directbiologics.com.

About Direct BiologicsDirect Biologics, LLC, is headquartered in Austin, Texas, with an R&D facility located at the University of California, and an Operations and Order Fulfillment Center located in San Antonio, Texas. Direct Biologics is a market-leading innovator and cGMP manufacturer of regenerative medical products, including a robust EV platform technology. Direct Biologics' management team holds extensive collective experience in biologics research, development, and commercialization, making the Company a leader in the evolving segment of next generation regenerative biotherapeutics. Direct Biologics has obtained and is pursuing multiple additional clinical indications for ExoFlo through the FDA's investigational new drug (IND) process. For more information visit http://www.directbiologics.com.

Photo - https://mma.prnewswire.com/media/1781269/Direct_biologics_Logo.jpg

SOURCE Direct Biologics

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FDA Grants Direct Biologics Regenerative Medicine Advanced Therapy (RMAT) Designation for the use of ExoFlo in COVID-19 Related ARDS USA - English -...

Bone Marrow Stem Cells Comments Off on FDA Grants Direct Biologics Regenerative Medicine Advanced Therapy (RMAT) Designation for the use of ExoFlo in COVID-19 Related ARDS USA – English -… | April 15th, 2022

Dr Jackson Orem, the Director of the Cancer Institute, gave a detailed patient history to highlight the cause of the departed former speaker Jacob Oulanyahs death at the State funeral in Kololo, Kampala. last Wednesday.

Eloquent he was in narrating that the patient had utilised the two lines of treatment available in Uganda and was only left with two experimental options including stem cell therapy.

Stem cell therapy involves extraction of bone marrow cells and implanting them in the body to rejuvenate its ability to produce white blood cells. In the case of the former Speaker, the Minister of Health Dr Ruth Aceng highlighted that the patient had lost his spleen decades ago compromising his immunity. She read from the post mortem report the patient suffered from a compound of various bacterial and viral infections and succumbed to multiple organ failure.

In all these, perhaps the only addition would have come from a pathologist to elaborate further and pinpoint the exact cause of death. Pathologists are the academic doctors who study forms of life in its innate forms, whether as tissue, examining dead bodies etc. In some analyses these are supported by microbiologists. All these people exist in close proximity on Mulago Hill and the new national testing center at Butabika. Listening to Dr Orem it is clear Ugandas problem is not the diagnostic part.

The diagnostic part has only failed in delivery to the general population due to its prohibitive cost. For most patients it is the treatment part that drives patients and their families to desperation.

The stories of the on-and off operations of the two cobalt machines in Mulago that administer radiotherapy is well documented. Radiotherapy burns the cancerous cells that are trying to outnumber the white cells that produce antibodies to defend the body from infections.

There are a few things Dr Orem may have inserted in the national conversation. First is the rising number of cancer cases. Last count says 30,000 cases but these are the diagnosed cases processed through the Cancer Institute. All non-communicable diseases are on the rise. Cancer is just behind cardio-vascular diseases. Others are chronic respiratory diseases, type 2 diabetes mellitus (DM), and chronic kidney disease.

A recent study in 2021 in BMC Journal shows that rural areas are seeing as much of an upswing as urban areas where conditions like cancer are associated with lifestyle. Non communicable diseases are a big profit center for big pharma as management costs are high. Its an area where name brands have overwhelmed generic drugs.

The other version of cancer triggers are stress and chemicals in the water supply. The introduction of contraceptives in the 1970s as women entered the workforce is blamed for a surge in a generation of mothers. GMO foods which have made cooking oil a staple in many homes are also a factor.

Processed foods are also a factor, including artificial colouring, hydrogenated fats and saturated oils. Very few Ugandans know that cooking oil can easily run a diesel engine.

During the Covid pandemic, NCD patients suffered more from the ravages of the disease, including debilitating strokes, heart attacks that played on the vulnerabilities NCD sufferers find themselves in.

Managing these diseases is only going to get more complicated as the big anchor in the healthcare supply system USAID is exiting.

The cancer center is already too small, patients waiting for hours in agony for relief. In the Covid interlude, Mulago (when patients dropped between January and April 2021), offered excellent care to in-patients.

This all round model can be replicated for cancer patients. If there is excess capacity at the new womens hospital it could be used. Cancer is a one way street, all the urgency that people are treated with dignity.

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Hoth Therapeutics (NASDAQ:HOTH) has gained ~135% in the pre-market Monday after the development-stage pharmaceutical company announced encouraging preclinical data for its investigational cancer therapy, HT-KIT.

KIT is designed to target the receptor tyrosine kinase KIT in mast cells, required for the normal functioning of bone marrow-derived hematopoietic stem cells. The mutations of the KIT pathway are linked to human cancers, such as gastrointestinal stromal tumors and mast cell-derived cancers.

According to the company, a team of researchers, who were part of a scientific research agreement with North Carolina State University, found that KIT protein expression, signaling, and function reduced in response to HT-KIT mRNA frame-shifting approach on mast cell leukemia cells in vitro.

The treatment was found to have prevented cancer cell growth and induced cell death over 72 hours.

Additionally, in a mouse model with mast cell leukemia, the tumor growth and infiltration of other organs reduced, and tumor cell death rose when HT-KIT induced frameshifted c-KIT mRNA, Hoth (HOTH) said.

Our next round of preclinical studies are underway and we are excited to utilize the results for our planned Pre-IND meeting with FDA later this year," Chief Executive Robb Knie said.

HT-KIT was granted the FDAs Orphan Drug designation early this year.

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Hoth Therapeutics surges on preclinical data for cancer therapy - Seeking Alpha

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The addition of the E-selectin antagonist uproleselan (GMI-1271) to chemotherapy has been shown to improve outcomes in patients with relapsed/refractory acute myeloid leukemia (AML), according to Tapan M. Kadia, MD, who added that based on these findings, the investigative agent is now under further exploration in several disease subsets and settings with varying unmet need.

The idea is that [uproleselan] may reduce or subvert chemotherapy resistance. This has been shown in several preclinical studies where mice that had been treated with cytarabine and had leukemic blasts left over after [treatment] showed that they had tight binding to E-selectin within the tumor microenvironment, Kadia explained. When uproleselan, or an antibody blocking E-selectin, was added, those cells then became sensitive to the cytarabine, suggesting that the E-selectin binding was leading to chemotherapy resistance. This [supported the hypothesis that] blocking E-selectin within the microenvironment can be an important mechanism to provide benefit in patients with AML.

Data from a phase 1/2 clinical trial (NCT02306291) showed that when uproleselan was administered at the recommended phase 2 dose of 10 mg/kg twice daily in combination with mitoxantrone, etoposide, and cytarabine (MEC), it produced a remission rate of 41% in those with relapsed/refractory disease (n = 47).1 In a cohort of patients with newly diagnosed disease who were at least 60 years of age (n = 25), the combination of uproleselan plus cytarabine and idarubicin (7+3) resulted in a remission rate of 72%.

Now, a phase 3 trial (NCT03616470) is examining MEC or fludarabine, cytarabine, and idarubicin (FAI) with or without uproleselan in patients with relapsed/refractory AML who are eligible for intensive chemotherapy in the salvage setting.2 Another phase 3 trial (NCT03701308) is exploring 7+3 chemotherapy with or without uproleselan in patients aged 60 years or older who are fit for intensive induction chemotherapy.3 Moreover, a phase 1/2 trial (NCT04848974) is evaluating cladribine and low-dose cytarabine in combination with uproleselan in difficult-to-treat patients with treated secondary AML.4

In an interview with OncLive, Kadia, an associateprofessor in the Department of Leukemia, of the Division of Cancer Medicine, at The University of Texas MD Anderson Cancer Center, discussed what makes uproleselan unique from other agents under investigation in AML and shed light on the many research efforts dedicated to further exploring its use in this disease.

Kadia: E-selectin is a relatively new target, but it is a protein that we have known about for many years. E-selectin is present on activated endothelial cells, [which are] the cells that make up a blood vessel. E-selectin is present, upregulated, and overexpressed in activated endothelial cells at the sites of inflammation and damage.

We [believe] E-selectin is meant to help attract or traffic leukocytes and white blood cells, including monocytes, neutrophils, and natural killer [NK] cells, to the sites of inflammation. Neutrophils, NK cells, and monocytes have E-selectin ligands, which are glycoproteins that are attracted to or attached to E-selectin. E-selectin on the endothelial cells helps to traffic these cells and adhere them to the endothelial cells.

More recently, E-selectin has become recognized as a potentially important marker in malignancy, because they are also expressed in endothelial cells associated with malignancy. For example, in solid tumors, there is a suggestion that it may have a role in metastasis or distant metastasis of solid tumors, such as colon cancer.

In leukemia and hematologic malignancies, the endothelial cells in bone marrow also overexpress E-selectin, particularly in advanced disease. They are expressed at higher levels in patients who have adverse-risk AML, patients who have been previously treated, and they allow the adherence of leukemic blasts of the malignant cells to the endothelial microenvironment within the bone marrow.

As [the endothelial cells do that], we believe that the E-selectin binding to these cells upregulates nuclear factor kappa B [NF-B] within the tumor or the blast, and elicits a type of chemotherapy resistance, or prosurvival pathways, that allow them to survive chemotherapy or treatment. Blocking this [from happening] has been the rationale behind [the development of] uproleselan. Blocking this may help prevent the trafficking of the blast cells to the bone marrow and from adhering to the bone marrow microenvironment, therefore inhibiting activation of the cancer survival pathways, such as NF-B.

Uproleselan is an antagonist of E-selectin that binds to E-selectin and prevents the interaction between E-selectin and E-selectin ligands, which are present on leukemia or AML blasts. It is an intravenous product that is given over 20 minutes twice daily.

[During] an initial study, [investigators] observed no significant toxicities [with uproleselan] as a single agent. The mechanism is that it blocks the interaction between the E-selectin and the E-selectin ligands on the blasts, therefore reducing the trafficking of these leukemic blasts to the bone marrow. It disrupts the adhesion-mediated drug resistance within the bone marrow microenvironment.

In that respect, it also inhibits the activation of potential cancer survival mechanisms, such as upregulation of NF-B, and may reduce chemotherapy-based toxicity that may occur. By reducing [E-selectin adhesion] and adding chemotherapy, you are treating cells that are potentially more sensitive to [chemotherapy].

The [hypothesis] was that blocking E-selectin would thereby sensitize the resistant leukemic blasts to chemotherapy, particularly in the salvage setting. You want to start in patients with relapsed/refractory AML.

This was a phase 1 study that looked at the combination of the E-selectin antagonist, uproleselan, with either MEC chemotherapy in patients with relapsed/refractory AML, or in combination with 7+3 chemotherapy in a small cohort of newly diagnosed patients with AML who were aged 60 years and older. Once patients achieved remission, they could also get uproleselan with their consolidation, whether it be MEC consolidation or intermediate-dose cytarabine-based consolidation.

A total of 66 patients with relapsed/refractory AML were treated, with a median age of 59 years of age. Moreover, 17% of those patients had prior transplant, and one-third of the patients had 2 or more induction regimens; [as such, it was] a heavily pretreated population. Fifty percent of patients had adverse-risk [disease] by European LeukemiaNet risk [classification].

If you look at the adverse [effects (AEs)], and this is 1 of the first striking observations, there may have been potentially lower toxicityparticularly along the gastrointestinal tract starting with mucositis, nausea, and vomitingthan what you would expect with MEC chemotherapy based on historical experience. The most common complications were infections, which are common in patients [with leukemia] who are treated with intensive chemotherapy.

When you look at efficacy among the 66 patients who were treated, the complete response [CR]/CR with incomplete count recovery [CRi] rate was [41%], and the early mortality [rate] was fairly low, at 9% at 60 days, which is reasonable. Patients who had a longer CR1 duration had a higher response rate at 75% vs those who had refractory disease or a short CR1 duration, [with] response rates in the range of 23% and 36%.

[Additionally], 69% of patients had minimal residual disease [MRD] negativity, which is good for a relapsed/refractory cohort setting. The efficacy was there, as seen by the overall response rate [ORR] of 39%, which is in line with what you would expect with salvage chemotherapy in the relapsed/refractory setting. The median overall survival [OS] of the patients is [8.8] months, [which is] promising for a study looking at relapsed/refractory AML.

One of the interesting correlative studies looked at E-selectin ligand expression on the blast cells and survival. Looking at baseline AML, a prior study suggested that patients whose blasts had high expression of E-selectin ligand had a more adverse prognosis then those with low expression. Moreover, E-selectin ligand overexpression [is known to] correlate with relapsed/refractory disease and adverse prognosis disease. As such, high E-selectin ligand is associated with a poor prognosis.

[However, in this correlative study,] patients who had high E-selectin ligand expression and were treated with uproleselan had a more favorable outcome, with a median OS of 12.7 months compared with 5.2 months in those who had low [E-selectin ligand] expression. That suggests that in those patients who typically would have a more adverse prognosis with high E-selectin ligand expression, when you added uproleselan, which blocked that interaction, their prognosis improved. That was an early signal that suggested that targeting that receptor flips the adverse prognosis associated with E-selectin ligand expression.

[The phase 1/2] study also had an arm of newly diagnosed patients, who were treated with 7+3 chemotherapy plus [uproleselan]. These were older patients with newly diagnosed AML; [this cohort was comprised of] 25 patients who had a median age of 67 years. Half of patients had secondary AML, which is commonly seen in that population.

Here, the rates of grade 3 or 4 mucositis were 0%, with about 20% [of patients experiencing] grade 1/2 mucositis, so lower rates in mucositis than we may have expected with intensive chemotherapy. The CR/CRi rate was 72% [with this approach], with 52% [of patients] achieving a complete remission. The early mortality [rate] at 60 days was 12%, [which is] higher than you might expect in older patients, but still reasonable and promising. The MRD negativity [rate] was 56% among the patients who were evaluated for it. As such, this was a pretty good response rate that was in line or higher than what you would expect with intensive chemotherapy.

Based on the promising data from the phase 1 trial, looking at patients with relapsed/refractory AML treated with MEC plus uproleselan, as well as the small cohort of frontline patients treated with uproleselan and 7+3, the sponsor decided to proceed with a couple of phase 3 randomized trials to register uproleselan for patients in these particular settings.

The primary end point for both studies is OS, to evaluate the combination of anti-leukemic activity uproleselan with the respective chemotherapy. Secondary end points also include trying to further study and nail down the incidence of severe oral mucositis. Is it less than what you would expect with the control arm?

The first is a randomized phase 3 study [NCT03616470] for patients between the ages of 18 years and 75 years, with relapsed/refractory AML who are eligible for intensive chemotherapy in the salvage setting. They may have had 1 or fewer allogeneic stem cell transplants [ASCTs] prior to enrollment. Patients are randomized [1:1] to either MEC or FAI chemotherapy, plus or minus uproleselan. If patients achieved remission, they could receive consolidation with high-dose [cytarabine] or intermediate-dose [cytarabine], plus or minus uproleselan. The primary end point of the study is OS. The study is in the early stages [and we] hope to see data in the next couple of years.

The second is an National Cancer Institute study [NCT03701308] that is looking at patients aged 60 years or older who are fit for intensive chemotherapy [in the frontline setting]. Patients who have secondary AML [will be included], but those with FLT3-mutated AML [will not], since there is a standard of care for that [in the form of] FLT3 inhibitors.

Here, patients are randomized [1:1] to 7+3 chemotherapy with or without uproleselan, with consolidation with intermediate-dose cytarabine, with or without uproleselan. The primary end point [is] OS, and there will be an interim analysis looking at event-free survival [EFS]. If there is an inferior EFS at the interim [analysis], then the study would be closed at that point for futility. Otherwise, it would continue to look for OS benefit [with this approach]. Hopefully, we will see some data in the next year or 2 [to shed light on whether] this is a good strategy [for these pateints].

The treatment paradigm in AML has shifted significantly over the past few years with the incorporation of new molecules, such as venetoclax [Venclexta], [plus] IDH1, IDH2, and FLT3 inhibitors. Things are changing rapidly, even as uproleselan is being developed.

Now, instead of saying we have patients who are older and fit for chemotherapy, you must ask [questions about mutations]. Does a patient have a FLT3 mutation? If so, maybe they should be treated with a FLT3 inhibitor combined with chemotherapy. Does a patient have an IDH1 or IDH2 mutation? Recent data from the 2021 ASH Annual Meeting suggested that the combination of ivosidenib [Tibsovo] and azacitidine showed a significant survival benefit in patients who are IDH1 mutated compared with azacitidine alone. As such, there is another option for that specific subset of patients.

We have other medications or intensive chemotherapy for patients who have secondary AML. [For example,] CPX-351 showed a significant survival benefit compared with 7+3 chemotherapy. Where does uproleselan fit in secondary AML? Well, if you start with the relapsed/refractory setting, there is no 1 standard of care. As such, if uproleselan does show significant benefit compared with MEC alone in terms of survival, that is one place to go.

[If patients] have FLT3-, IDH1-, or IDH2-mutated, options such as gilteritinib [Xospata] and ivosidenib are available for those respective subtypes. However, in those patients who do not have those mutations, [uproleselan] could be an option.

A [phase 1/2] pilot study [NCT03214562] that is being done by [investigators at The University of MD Anderson Cancer Center] looked at [the combination of] FLAG [fludarabine, cytarabine, granulocyte colonystimulating factor] plus idarubicin and venetoclax [in patients with relapsed/refractory AML] and showed very high rates of complete remission with MRD negativity. This is a very intensive study, that needs close follow-up and close safety evaluation, but certainly, [we are seeing] high response rates with most of the patients able to proceed to ASCT and good survival in the long term. How does uproleselan fit in that setting?

If [the addition of uproleselan] shows a benefit over MEC as a single agent, it is certainly an option. [Now, we must determine] which patients you would put on that particular study, if they have no targetable mutations or if they cannot tolerate intensive chemotherapy plus venetoclax, whether it be FLAG plus idarubicin/venetoclax, or a regimen we developed, [like CPX-351] plus venetoclax.

In the frontline setting, it gets even more difficult because frontline studies are looking at [combining] a hypomethylating agent [HMA] with venetoclax in older patients. This [approach] is currently approved for patients who are aged 75 and older, or those who are unfit for intensive chemotherapy. However, [this approach] may start to be applied to patients who are slightly younger than that or who are more fit than the most unfit patients. [Investigators] are examining HMA plus venetoclax in that older, fit population. New regimens, such as cladribine, low-dose cytarabine, plus venetoclax, have also demonstrated high response rates in that older, fit population.

A set of studies is evaluating [CTX-351 in secondary AML]. For patients with IDH1 mutations, we now have the option of HMA plus ivosidenib. For FLT3-mutated disease, we are still looking, but HMA/venetoclax has high response rates in that setting. Moreover, triplet combinations are also being investigated, where [agents such as] gilteritinib or quizartinib are being added to the backbone of HMA plus venetoclax.

In the frontline, so many different options [are available] for specific subtypes, so we must define where 7+3 plus uproleselan will fit in, if data are positive. This is still a question that will need to be answered.

We are conducting a trial in a specific subset of patients who do not have great options [available to them] right now: those with treated secondary AML. This is a population of patients who may have had myelodysplastic syndrome [MDS] or chronic myelomonocytic leukemia [CMML] prior to developing AML, which is very common in the population. These patients were treated with the standard of care, which is HMAs and 5-azacytidine or decitabine in the frontline for MDS or CMML.

Eventually, these patients may respond [to treatment], but they may then progress to AML. At the time of their progression, they are considered to have newly diagnosed AML, but they may have received months or years of HMAs. This [scenario] used to be [referred to as] HMA failure, but this is a specific subset of AML that arises from previously treated MDS or CMML. In these patients, the complete remission rates are in the range of 20% to 25% with standard agents, and early mortality is very high. These patients have a median OS in the range of 4 to 5 months at the time of diagnosis AML, so it is a difficult subset of patients [to treat] for whom there really is no therapy [available]. If you look at CPX-351 in that setting, which is treated secondary AML, outcomes are pretty much the same, with high rates of early mortality and poor OS.

We wanted to address this key subset of patients. One of the things that we learned from the preclinical studies with uproleselan is that E-selectin is upregulated and overexpressed in AML blasts that have been previously exposed to HMAs. AML or MDS blasts that have been treated with or exposed to HMAs upregulate E-selectin significantly. The rationale was if these patients who have failed or have been treated extensively with HMAs then develop AML, their blasts may have upregulated E-selectin, and they may be the ideal target for uproleselan in combination with chemotherapy.

We took that specific subset of patients, and we are studying the combination of uproleselan plus cladribine and low-dose cytarabine [as part of a phase 1/2 trial (NCT04848974)]. The cladribine and low-dose cytarabine regimen has been developed at MD Anderson and, for many years now, has been used in frontline AML and treated secondary AML. In that specific subset [of treated secondary AML], we have seen a response rate [ranging from] 35% to 40% in the frontline [setting].

Since it is not [additional treatment with a] HMA, this backbone in combination with uproleselan is being studied in patients with treated secondary AML, with the end point of safety, [as well as] secondary end points of remission rate and OS in this difficult population, where there is a [need] that needs to be critically addressed.

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Acta Naturae. 2010 Jul; 2(2): 1828.

Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences

Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences

Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences

Research Center of Clinical and Experimental Medicine, Siberian Branch, Russian Academy of Medical Sciences

Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences

Research Center of Clinical and Experimental Medicine, Siberian Branch, Russian Academy of Medical Sciences

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Induced pluripotent stem cells (iPSCs) are a new type of pluripotent cellsthat can be obtained by reprogramming animal and human differentiated cells. In this review,issues related to the nature of iPSCs are discussed and different methods ofiPSC production are described. We particularly focused on methods of iPSC production withoutthe genetic modification of the cell genome and with means for increasing the iPSC productionefficiency. The possibility and issues related to the safety of iPSC use in cell replacementtherapy of human diseases and a study of new medicines are considered.

Keywords: induced pluripotent stem cells, directed stem cell differentiation, cell replacement therapy

Pluripotent stem cells are a unique model for studying a variety of processes that occur inthe early development of mammals and a promising tool in cell therapy of human diseases. Theunique nature of these cells lies in their capability, when cultured, for unlimitedselfrenewal and reproduction of all adult cell types in the course of theirdifferentiation [1]. Pluripotency is supported by acomplex system of signaling molecules and gene network that is specific for pluripotent cells.The pivotal position in the hierarchy of genes implicated in the maintenance of pluripotency isoccupied by Oct4, Sox2 , and Nanog genes encodingtranscription factors [2, 3]. The mutual effect of outer signaling molecules and inner factors leads tothe formation of a specific expression pattern, as well as to the epigenome statecharacteristic of stem cells. Both spontaneous and directed differentiations are associatedwith changes in the expression pattern and massive epigenetic transformations, leading totranscriptome and epigenome adjustment to a distinct cell type.

Until recently, embryonic stem cells (ESCs) were the only wellstudied source ofpluripotent stem cells. ESCs are obtained from either the inner cell mass or epiblast ofblastocysts [46]. A series of protocols has been developed for the preparation of variouscell derivatives from human ESCs. However, there are constraints for ESC usein cell replacement therapy. The first constraint is the immune incompatibility between thedonor cells and the recipient, which can result in the rejection of transplanted cells. Thesecond constraint is ethical, because the embryo dies during the isolation of ESCs. The firstproblem can be solved by the somatic cell nuclear transfer into the egg cell and then obtainingthe embryo and ESCs. The nuclear transfer leads to genome reprogramming, in which ovariancytoplasmic factors are implicated. This way of preparing pluripotent cells from certainindividuals was called therapeutic cloning. However, this method is technologyintensive,and the reprogramming yield is very low. Moreover, this approach encounters theabovementioned ethic problem that, in this case, is associated with the generation ofmany human ovarian cells [7].

In 2006, the preparation of pluripotent cells by the ectopic expression of four genes Oct4 , Sox2 , Klf4 , and cMyc in both embryonic and adult murine fibroblasts was first reported[8]. The pluripotent cells derived from somatic ones werecalled induced pluripotent stem cells (iPSCs). Using this set of factors(Oct4, Sox2, Klf4, and cMyc), iPSCs were prepared later from variousdifferentiated mouse [914] and human [1517] cell types. Human iPSCs were obtainedwith a somewhat altered gene set: Oct4 , Sox2 , Nanog , and Lin28 [18].Induced PSCs closely resemble ESCs in a broad spectrum of features. They possess similarmorphologies and growth manners and are equally sensitive to growth factors and signalingmolecules. Like ESCs, iPSCs can differentiate in vitro intoderivatives of all three primary germ layers (ectoderm, mesoderm, and endoderm) and formteratomas following their subcutaneous injection into immunodeficient mice. MurineiPSCs injected into blastocysts are normally included in the development toyield animals with a high degree of chimerism. Moreover, murine iPSCs, wheninjected into tetraploid blastocycts, can develop into a whole organism [19, 20]. Thus, an excellent method thatallows the preparation of pluripotent stem cells from various somatic cell types whilebypassing ethical problems has been uncovered by researchers.

In the first works on murine and human iPSC production, either retro or lentiviralvectors were used for the delivery of Oct4 , Sox2 , Klf4 , and cMyc genes into somatic cells. Theefficiency of transduction with retroviruses is high enough, although it is not the same fordifferent cell types. Retroviral integration into the host genome requires a comparatively highdivision rate, which is characteristic of the relatively narrow spectrum of cultured cells.Moreover, the transcription of retroviral construct under the control of a promoter localizedin 5LTR (long terminal repeat) is terminated when the somatic celltransform switches to the pluripotent state [21]. Thisfeature makes retroviruses attractive in iPSC production. Nevertheless, retroviruses possesssome properties that make iPSCs that are produced using them improper for celltherapy of human diseases. First, retroviral DNA is integrated into the host cell genome. Theintegration occurs randomly; i.e., there are no specific sequences or apparent logic forretroviral integration. The copy number of the exogenous retroviral DNA that is integrated intoa genome may vary to a great extent [15]. Retrovirusesbeing integrated into the cell genome can introduce promoter elements and polyadenylationsignals; they can also interpose coding sequences, thus affecting transcription. Second, sincethe transcription level of exogenous Oct4 , Sox2 , Klf4 , and cMyc in the retroviral constructdecreases with cell transition into the pluripotent state, this can result in a decrease in theefficiency of the stable iPSC line production, because the switch from the exogenous expressionof pluripotency genes to their endogenous expression may not occur. Third, some studies showthat the transcription of transgenes can resume in the cells derived fromiPSCs [22]. The high probability thatthe ectopic Oct4 , Sox2 , Klf4 , and cMyc gene expression will resume makes it impossible to applyiPSCs produced with the use of retroviruses in clinical trials; moreover,these iPSCs are hardly applicable even for fundamental studies onreprogramming and pluripotency principles. Lentiviruses used for iPSC production can also beintegrated into the genome and maintain their transcriptional activity in pluripotent cells.One way to avoid this situation is to use promoters controlled by exogenous substances added tothe culture medium, such as tetracycline and doxycycline, which allows the transgenetranscription to be regulated. iPSCs are already being produced using suchsystems [23].

Another serious problem is the gene set itself that is used for the induction of pluripotency[22]. The ectopic transcription of Oct4 , Sox2 , Klf4 , and cMyc can lead to neoplastic development from cells derived from iPSCs,because the expression of Oct4 , Sox2 , Klf4, and cMyc genes is associated with the development ofmultiple tumors known in oncogenetics [22, 24]. In particular, the overexpression of Oct4 causes murine epithelial cell dysplasia [25],the aberrant expression of Sox2 causes the development of serrated polypsand mucinous colon carcinomas [26], breast tumors arecharacterized by elevated expression of Klf4 [27] , and the improper expression of cMyc is observed in 70% of human cancers [28].Tumor development is oberved in ~50% of murine chimeras obtained through the injection ofretroviral iPSCs into blastocysts, which is very likely associated with thereactivation of exogenous cMyc [29, 30].

Several possible strategies exist for resolving the above-mentioned problems:

The search for a less carcinogenic gene set that is necessary and sufficient for reprogramming;

The minimization of the number of genes required for reprogramming and searching for the nongenetic factors facilitating it;

The search for systems allowing the elimination of the exogenous DNA from the host cell genome after the reprogramming;

The development of delivery protocols for nonintegrated genetic constructs;

The search for ways to reprogram somatic cells using recombinant proteins.

The ectopic expression of cMyc and Klf4 genes isthe most dangerous because of the high probability that malignant tumors will develop [22]. Hence the necessity to find other genes that couldsubstitute cMyc and Klf4 in iPSC production. Ithas been reported that these genes can be successfully substituted by Nanog and Lin28 for reprogramming human somatic cells [18;] . iPSCs were prepared from murine embryonic fibroblastsby the overexpression of Oct4 and Sox2 , as well as the Esrrb gene encoding the murine orphan nuclear receptor beta. It has alreadybeen shown that Esrrb , which acts as a transcription activator of Oct4 , Sox2 , and Nanog , is necessary for theselfrenewal and maintenance of the pluripotency of murine ESCs. Moreover, Esrrb can exert a positive control over Klf4 . Thus, the genes causingelevated carcinogenicity of both iPSCs and their derivatives can besuccessfully replaced with less dangerous ones [31].

The Most Effectively Reprogrammed Cell Lines . Murine and humaniPSCs can be obtained from fibroblasts using the factors Oct4, Sox2, and Klf4,but without cMyc . However, in this case, reprogramming deceleratesand an essential shortcoming of stable iPSC clones is observed [32, 33]. The reduction of a number ofnecessary factors without any decrease in efficiency is possible when iPSCsare produced from murine and human neural stem cells (NSCs) [12, 34, 35]. For instance, iPSCs were produced fromNSCs isolated from adult murine brain using two factors, Oct4 and Klf4, aswell as even Oct4 by itself [12, 34]. Later, human iPSCs were produced by the reprogramming offetal NSCs transduced with a retroviral vector only carrying Oct4 [35] . It is most likely that the irrelevanceof Sox2, Klf4, and cMyc is due to the high endogenous expression level of these genes inNSCs.

Successful reprogramming was also achieved in experiments withother cell lines, in particular, melanocytes of neuroectodermal genesis [36]. Both murine and human melanocytes are characterized by a considerableexpression level of the Sox2 gene, especially at early passages.iPSCs from murine and human melanocytes were produced without the use of Sox2or cMyc. However, the yield of iPSC clones produced from murine melanocytes was lower(0.03% without Sox2 and 0.02% without cMyc) in comparison with that achieved when allfour factors were applied to melanocytes (0.19%) and fibroblasts (0.056%). A decreasedefficiency without Sox2 or cMyc was observed in human melanocyte reprogramming (0.05%with all four factors and 0.01% without either Sox2 or cMyc ). All attempts to obtain stable iPSC clones in the absence of both Sox2 andcMyc were unsuccessful [36]. Thus, theminimization of the number of factors required for iPSC preparation can be achieved by choosingthe proper somatic cell type that most effectively undergoes reprogramming under the action offewer factors, for example, due to the endogenous expression of pluripotencygenes. However, if human iPSCs are necessary, these somatic cellsshould be easily accessible and wellcultured and their method of isolation should be asnoninvasive as possible.

One of these cell types can be adipose stem cells (ASCs). This is aheterogeneous group of multipotent cells which can be relatively easily isolated in largeamounts from adipose tissue following liposuction. Human iPSCs weresuccessfully produced from ASCs with a twofold reprogramming rate and20fold efficiency (0.2%), exceeding those of fibroblasts [37].

However, more accessible resources for the effective production of humaniPSCs are keratinocytes. When compared with fibroblasts, human iPSC productionfrom keratinocytes demonstrated a 100fold greater efficiency and a twofold higherreprogramming rate [38].

It has recently been found that the reprogramming of murine papillary dermal fibroblasts(PDFs) into iPSCs can be highly effective with theoverexpression of only two genes, Oct4 and Klf4 ,inserted into retroviral vectors [39;].PDFs are specialized cells of mesodermal genesis surrounding the stem cells ofhair follicles . One characteristic feature of these cells is the endogenous expression of Sox2 , Klf4 , and cMyc genes,as well as the geneencoding alkaline phosphatase, one of the murine and humanESC markers. PDFs can be easily separated from other celltypes by FACS (fluorescenceactivated cell sorting) using life staining with antibodiesagainst the surface antigens characteristic of one or another cell type. The PDF reprogrammingefficiency with the use of four factors (Oct4, Sox2, Klf4, and cMyc) retroviral vectorsis 1.38%, which is 1,000fold higher than the skin fibroblast reprogramming efficiency inthe same system. Reprogramming PDFs with two factors, Oct4 and Klf4 , yields 0.024%, which is comparable to the efficiency of skinfibroblast reprogramming using all four factors. The efficiency of PDF reprogramming iscomparable with that of NSCs, but PDF isolation is steady and far lessinvasive [39]. It seems likely that human PDF lines arealso usable, and this cell type may appear to be one of the most promising for human iPSCproduction in terms of pharmacological studies and cell replacement therapy. The use of suchcell types undergoing more effective reprogramming, together with methods providing thedelivery of pluripotency genes without the integration of foreign DNA into thehost genome and chemical compounds increasing the reprogramming efficiency and substitutingsome factors required for reprogramming, is particularly relevant.

Chemical Compounds Increasing Cell Reprogramming Efficiency. As was noted above,the minimization of the factors used for reprogramming decreases the efficiency of iPSCproduction. Nonetheless, several recent studies have shown that the use of genetic mechanisms,namely, the initiation of ectopic gene expression, can be substituted by chemical compounds,most of them operating at the epigenetic level. For instance, BIX01294 inhibitinghistone methyltransferase G9a allows murine fibroblast reprogramming using only two factors,Oct4 and Klf4, with a fivefold increased yield of iPSC clones in comparison with the controlexperiment without BIX01294 [40]. BIX01294taken in combination with another compound can increase the reprogramming efficiency even more.In particular, BIX01294 plus BayK8644 elevated the yield of iPCSs 15 times, andBIX01294 plus RG108 elevated it 30 times when only two reprogramming factors, Oct4 andKlf4, were used. RG108 is an inhibitor of DNA methyltransferases, and its role in reprogrammingis apparently in initiating the more rapid and effective demethylation of promoters ofpluripotent cellspecific genes, whereas BayK8644 is an antagonist of Ltypecalcium channels, and its role in reprogramming is not understood very well [40]. However, more considerable results were obtained inreprogramming murine NSCs. The use of BIX01294 allowed a 1.5foldincrease in iPSC production efficiency with two factors, Oct4 and Klf4, in comparison withreprogramming with all four factors. Moreover, BIX01294 can even substitute Oct4 in thereprogramming of NSCs, although the yield is very low [41]. Valproic (2propylvaleric) acid inhibiting histone deacetylases canalso substitute cMyc in reprogramming murine and human fibroblasts. Valproic acid (VPA)increases the reprogramming efficiency of murine fibroblasts 50 times, and human fibroblastsincreases it 1020 times when three factors are used [42, 43]. Other deacetylase inhibitors,such as TSA (trichostatin A) and SAHA (suberoylanilide hyroxamic acid), also increase thereprogramming efficiency. TSA increases the murine fibroblast reprogramming efficiency 15times, and SAHA doubles it when all four factors are used [42]. Besides epigenetic regulators, the substances inhibiting the proteincomponents of signaling pathways implicated in the differentiation of pluripotent cells arealso applicable in the substitution of reprogramming factors. In particular, inhibitors of MEKand GSK3 kinases (PD0325901 and CHIR99021, respectively) benefit the establishment of thecomplete and stable pluripotency of iPSCs produced from murineNSCs using two factors, Oct4 and Klf4 [41, 44].

It has recently been shown that antioxidants can considerably increase the efficiency ofsomatic cell reprogramming. Ascorbic acid (vitamin C) can essentially influence the efficiencyof iPSC production from various murine and human somatic cell types [45]. The transduction of murine embryonic fibroblasts (mEFs) with retrovirusescarrying the Oct4 , Sox2 , and Klf4 genes results in a significant increase in the production level of reactive oxygen species(ROS) compared with that of both control and Efs tranduced with Oct4 , Sox2 , cMyc , and Klf4 . Inturn, the increase in the ROS level causes accelerated aging and apoptosis of the cell, whichshould influence the efficiency of cell reprogramming. By testing several substances possessingantioxidant activity such as vitamin B1, sodium selenite, reduced glutathione, and ascorbicacid, the authors have found that combining these substances increases the yield ofGFPpositive cells in EF reprogramming (the Gfp genewas under the control of the Oct4 gene promoter). The use of individualsubstances has shown that only ascorbate possesses a pronounced capability to increase thelevel of GFPpositive cells, although other substances keep theirROSdecreasing ability. In all likelihood, this feature of ascorbates is not directlyassociated with its antioxidant activity [45]. The scoreof GFPpositive iPSC colonies expressing an alkaline phosphatase hasshown that the efficiency of iPSC production from mEFs with three factors (Oct4, Sox2, andKlf4) can reach 3.8% in the presence of ascorbate. When all four factors (Oct4, Sox2, Klf4, andcMyc) are used together with ascorbate, the efficiency of iPSC production may reach8.75%. A similar increase in the iPSC yield was also observed in the reprogramming of murinebreast fibroblasts; i.e., the effect of vitamin C is not limited by one cell type. Moreover,the effect of vitamin C on the reprogramming efficiency is more profound than that of thedeacetylase inhibitor valproic (2propylvaleric) acid. The mutual effect of ascorbate andvalproate is additive; i.e., these substances have different action mechanisms. Moreover,vitamin C facilitates the transition from preiPSCs to stablepluripotent cells. This feature is akin to the effects of PD0325901 and CHIR99021, which areinhibitors of MEK and GSK3 kinases, respectively. This effect of vitamin C expands to humancells as well [45]. Following the transduction of humanfibroblasts with retroviruses carrying Oct4 , Sox2 , Klf4 , and cMyc and treatment with ascorbate, theauthors prepared iPSCs with efficiencies reaching 6.2%. The reprogrammingefficiency of ASCs under the same conditions reached 7.06%. The mechanism ofthe effect that vitamin C has on the reprogramming efficiency is not known in detail.Nevertheless, the acceleration of cell proliferation was observed at the transitional stage ofreprogramming. The levels of the p53 and p21 proteins decreased in cells treated withascorbate, whereas the DNA repair machinery worked properly [45]. It is interesting that an essential decrease in the efficiency of iPSCproduction has been shown under the action of processes initiated by p53 and p21 [4650].

As was mentioned above, for murine and human iPSC production, both retro andlentiviruses were initially used as delivery vectors for the genes required for cellreprogramming. The main drawback of this method is the uncontrolled integration of viral DNAinto the host cells genome. Several research groups have introduced methods fordelivering pluripotency genes into the recipient cell which either do notintegrate allogenic DNA into the host genome or eliminate exogenous genetic constructs from thegenome.

CreloxP Mediated Recombination. To prepareiPSCs from patients with Parkinsons disease, lentiviruses were used,the proviruses of which can be removed from the genome by Cre recombinase. To do this, the loxP site was introduced into thelentiviral 3LTRregions containing separate reprogramming genesunder the control of the doxycyclineinducible promoter. During viral replication, loxP was duplicated in the 5LTR of the vector. As aresult, the provirus integrated into the genome was flanked with two loxP sites. The inserts were eliminated using the temporary transfection ofiPSCs with a vector expressing Cre recombinase[51].

In another study, murine iPSCs were produced using a plasmid carrying the Oct4 , Sox2 , Klf4I, and cMyc genes in the same reading frame in which individual cDNAs were separatedby sequences encoding 2 peptides, and practically the whole construct was flanked with loxP sites [52]. The use ofthis vector allowed a notable decrease in the number of exogenous DNA inserts in the hostcells genome and, hence, the simplification of their following excision [52]. It has been shown using lentiviruses carrying similarpolycistronic constructs that one copy of transgene providing a high expression level of theexogenous factors Oct4, Sox2, Klf4, and cMyc is sufficient for the reprogramming ofdifferentiated cells into the pluripotent state [53,54].

The drawback of the CreloxP system is the incomplete excisionof integrated sequences; at least the loxP site remains in thegenome, so the risk of insertion mutations remains.

Plasmid Vectors . The application of lentiviruses and plasmids carrying the loxP sites required for the elimination of transgene constructsmodifies, although insignificantly, the host cells genome. One way to avoid this is touse vector systems that generally do not provide for the integration of the whole vector orparts of it into the cells genome. One such system providing a temporary transfectionwith polycistronic plasmid vectors was used for iPSC production from mEFs [29]. A polycistronic plasmid carrying the Oct4 , Sox2 , and Klf4 gene cDNAs, as well as aplasmid expressing cMyc , was transfected into mEFs one, three, five,and seven days after their primary seeding. Fibroblasts were passaged on the ninth day, and theiPSC colonies were selected on the 25th day. Seven out of ten experiments succeeded inproducing GFPpositive colonies (the Gfp gene wasunder the control of the Nanog gene promoter). The iPSCsthat were obtained were similar in their features to murine ESCs and did not contain inserts ofthe used DNA constructs in their genomes. Therefore, it was shown that wholesome murineiPSCs that do not carry transgenes can be reproducibly produced, and that thetemporary overexpression of Oct4 , Sox2 , Klf4 , and cMyc is sufficient for reprogramming. The maindrawback of this method is its low yield. In ten experiments the yield varied from 1 to 29 iPSCcolonies per ten million fibroblasts, whereas up to 1,000 colonies per ten millions wereobtained in the same study using retroviral constructs [29].

Episomal Vectors . Human iPSCs were successfully produced fromskin fibroblasts using single transfection with polycistronic episomal constructs carryingvarious combinations of Oct4 , Sox2 , Nanog , Klf4 , cMyc , Lin28 , and SV40LT genes. These constructs were designed on the basis of theoriP/EBNA1 (EpsteinBarr nuclear antigen1) vector [55]. The oriP/EBNA1 vector contains the IRES2 linker sequence allowing theexpression of several individual cDNAs (encoding the genes required for successfulreprogramming in this case) into one polycistronic mRNA from which several proteins aretranslated. The oriP/EBNA1 vector is also characterized by lowcopy representation in thecells of primates and can be replicated once per cell cycle (hence, it is not rapidlyeliminated, the way common plasmids are). Under nonselective conditions, the plasmid iseliminated at a rate of about 5% per cell cycle [56]. Inthis work, the broad spectrum of the reprogramming factor combinations was tested, resulting inthe best reprogramming efficiency with cotransfection with three episomes containing thefollowing gene sets: Oct4 + Sox2 + Nanog + Klf4 , Oct4 + Sox2 + SV40LT + Klf4 , and cMyc + Lin28 . SV40LT ( SV40 large T gene )neutralizes the possible toxic effect of overexpression [57]. The authors have shown thatwholesome iPSCs possessing all features of pluripotent cells can be producedfollowing the temporary expression of a certain gene combination in human somatic cells withoutthe integration of episomal DNA into the genome. However, as in the case when plasmid vectorsare being used, this way of reprogramming is characterized by low efficiency. In separateexperiments the authors obtained from 3 to 6 stable iPSC colonies per 106transfected fibroblasts [55]. Despite the fact that skinfibroblasts are wellcultured and accessible, the search for other cell types which arerelatively better cultured and more effectively subject themselves to reprogramming throughthis method is very likely required. Another drawback of the given system is that this type ofepisome is unequally maintained in different cell types.

PiggyBacTransposition . One promising system used foriPSC production without any modification of the host genome is based on DNA transposons.Socalled PiggyBac transposons containing2linkered reprogramming genes localized between the 5 and3terminal repeats were used for iPSC production from fibroblasts. The integrationof the given constructs into the genome occurs due to mutual transfection with a plasmidencoding transposase. Following reprogramming due to the temporary expression of transposase,the elimination of inserts from the genome took place [58, 59]. One advantage of the PiggyBac system on CreloxP is that the exogenous DNA iscompletely removed [60].

However, despite the relatively high efficiency of exogenous DNA excision from the genome by PiggyBac transposition, the removal of a large number of transposoncopies is hardly achievable.

Nonintegrating Viral Vectors . Murine iPSCs were successfullyproduced from hepatocytes and fibroblasts using four adenoviral vectors nonintegrating into thegenome and carrying the Oct4 , Sox2 , Klf4 , and cMyc genes. An analysis of the obtainediPSCs has shown that they are similar to murine ESCs in their properties(teratoma formation, gene promoter DNA methylation, and the expression of pluripotent markers),but they do not carry insertions of viral DNA in their genomes [61]. Later, human fibroblastderived iPSCs wereproduced using this method [62].

The authors of this paper cited the postulate that the use of adenoviral vectors allows theproduction of iPSCs, which are suitable for use without the risk of viral oroncogenic activity. Its very low yield (0.00010.001%), the deceleration ofreprogramming, and the probability of tetraploid cell formation are the drawbacks of themethod. Not all cell types are equally sensitive to transduction with adenoviruses.

Another method of gene delivery based on viral vectors was recently employed for theproduction of human iPSCs. The sendaivirus (SeV)based vector wasused in this case [63]. SeV is a singlestrandedRNA virus which does not modify the genome of recipient cells; it seems to be a good vector forthe expression of reprogramming factors. Vectors containing either all pluripotencyfactors or three of them (without ) were used for reprogramming the human fibroblast. The construct based on SeV is eliminatedlater in the course of cell proliferation. It is possible to remove cells with the integratedprovirus via negative selection against the surface HN antigen exposed on the infected cells.The authors postulate that reprogramming technology based on SeV will enable the production ofclinically applicable human iPSCs [63].

Cell Transduction with Recombinant Proteins . Although the methods for iPSCproduction without gene modification of the cells genome (adenoviral vectors, plasmidgene transfer, etc.) are elaborated, the theoretical possibility for exogenous DNA integrationinto the host cells genome still exists. The mutagenic potential of the substances usedpresently for enhancing iPSC production efficiency has not been studied in detail. Fullychecking iPSC genomes for exogenous DNA inserts and other mutations is a difficult task, whichbecomes impossible to solve in bulk culturing of multiple lines. The use of protein factorsdelivered into a differentiated cell instead of exogenous DNA may solve this problem. Tworeports have been published to date in which murine and human iPSCs wereproduced using the recombinant Oct4, Sox2, Klf4, and cMyc proteins [64, 65] . T he methodused to deliver the protein into the cell is based on the ability of peptides enriched withbasic residues (such as arginine and lysine) to penetrate the cells membrane. MurineiPSCs were produced using the recombinant Oct4, Sox2, Klf4, and cMycproteins containing eleven Cterminal arginine residues and expressed in E. coli . The authors succeeded in producing murine iPSCs during four roundsof protein transduction into embryonic fibroblasts [65].However, iPSCs were only produced when the cells were additionally treatedwith 2propylvalerate (the deacetylase inhibitor). The same principle was used for theproduction of human iPSCs, but protein expression was carried out in humanHEK293 cells, and the proteins were expressed with a fragment of nine arginins at the proteinCend. Researchers have succeeded in producing human iPSCs after sixtransduction rounds without any additional treatment [64]. The efficiency of producing human iPSC in this way was 0.001%, which isone order lower than the reprogramming efficiency with retroviruses. Despite some drawbacks,this method is very promising for the production of patientspecificiPSCs.

The first lines of human pluripotent ESCs were produced in 1998 [6]. In line with the obvious fundamental importance of embryonic stem cellstudies with regard to the multiple processes taking place in early embryogenesis, much of theinterest of investigators is associated with the possibility of using ESCs and theirderivatives as models for the pathogenesis of human diseases, new drugs testing, and cellreplacement therapy. Substantial progress is being achieved in studies on directed humanESC differentiation and the possibility of using them to correct degenerativedisorders. Functional cell types, such as motor dopaminergic neurons, cardiomyocytes, andhematopoietic cell progenitors, can be produced as a result of ESCdifferentiation. These cell derivatives, judging from their biochemical and physiologicalproperties, are potentially applicable for the therapy of cardiovascular disorders, nervoussystem diseases, and human hematological disorders [66].Moreover, derivatives produced from ESCs have been successfully used for treating diseasesmodeled on animals. Therefore, bloodcell progenitors produced from ESCs weresuccessfully used for correcting immune deficiency in mice. Visual functions were restored inblind mice using photoreceptors produced from human ESCs, and the normal functioning of thenervous system was restored in rats modeling Parkinsons disease using the dopaminergicneurons produced from human ESCs [6770]. Despite obvious success, the fullscale applicationof ESCs in therapy and the modeling of disorders still carry difficulties, because of thenecessity to create ESC banks corresponding to all HLAhaplotypes, whichis practically unrealistic and hindered by technical and ethical problems.

Induced pluripotent stem cells can become an alternative for ESCs in the area of clinicalapplication of cell replacement therapy and screening for new pharmaceuticals.iPSCs closely resemble ESCs and, at the same time, can be produced in almostunlimited amounts from the differentiated cells of each patient. Despite the fact that thefirst iPSCs were produced relatively recently, work on directed iPSCdifferentiation and the production of patientspecific iPSCs isintensive, and progress in this field is obvious.

Dopamine and motor neurons were produced from human iPSCs by directeddifferentiation in vitro [71, 72]. These types of neurons are damaged in many inherited oracquired human diseases, such as spinal cord injury, Parkinsons disease, spinal muscularatrophy, and amyotrophic lateral sclerosis. Some investigators have succeeded in producingvarious retinal cells from murine and human iPSCs [7375]. HumaniPSCs have been shown to be spontaneously differentiated in vitro into the cells of retinal pigment epithelium [76]. Another group of investigators has demonstrated that treating human andmurine iPSCs with Wnt and Nodal antagonists in a suspended culture induces theappearance of markers of cell progenitors and pigment epithelium cells. Further treating thecells with retinoic acid and taurine activates the appearance of cells expressing photoreceptormarkers [75].

Several research groups have produced functional cardiomyocytes (CMs) in vitro from murine and human iPSCs [7781]. Cardiomyocytes producedfrom iPSC are very similar in characteristics (morphology, marker expression,electrophysiological features, and sensitivity to chemicals) to the CMs ofcardiac muscle and to CMs produced from differentiated ESCs. Moreover, murineiPSCs, when injected, can repair muscle and endothelial cardiac tissuesdamaged by cardiac infarction [77].

Hepatocytelike cell derivatives, dendritic cells, macrophages, insulinproducingcell clusters similar to the duodenal islets of Langerhans, and hematopoietic and endothelialcells are currently produced from murine and human iPSCs, in addition to thealreadylisted types of differentiated cells [8285].

In addition to directed differentiation in vitro , investigators apply mucheffort at producing patientspecific iPSCs. The availability ofpluripotent cells from individual patients makes it possible to study pathogenesis and carryout experiments on the therapy of inherited diseases, the development of which is associatedwith distinct cell types that are hard to obtain by biopsy: so the use ofiPSCs provides almost an unlimited resource for these investigations.Recently, the possibility of treating diseases using iPSCs was successfullydemonstrated, and the design of the experiment is presented in the figure. A mutant allele wassubstituted with a normal allele via homologous recombination in murine fibroblastsrepresenting a model of human sickle cell anemia. iPSCs were produced fromrepaired fibroblasts and then differentiated into hematopoietic cell precursors.The hematopoietic precursors were then injected into a mouse from which the skin fibroblastswere initially isolated (). As a result, the initialpathological phenotype was substantially corrected [86].A similar approach was applied to the fibroblasts and keratinocytes of a patient withFanconis anemia. The normal allele of the mutant gene producing anemia was introducedinto a somatic cell genome using a lentivirus, and then iPSCs were obtainedfrom these cells. iPSCs carrying the normal allele were differentiated intohematopoietic cells maintaining a normal phenotype [87].The use of lentiviruses is unambiguously impossible when producing cells to be introduced intothe human body due to their oncogenic potential. However, new relatively safe methods of genomemanipulation are currently being developed; for instance, the use of synthetic nucleasescontaining zinc finger domains allowing the effective correction of genetic defects invitro [88].

Design of an experiment on repairing the mutant phenotype in mice modeling sickle cell anemia development [2]. Fibroblasts isolatedfrom the tail of a mouse (1) carrying a mutant allele of the gene encoding the human hemoglobin -chain (hs) were used for iPSCproduction (2). The mutation was then repaired in iPSCs by means of homological recombination (3) followed by cell differentiationvia the embryoid body formation (4). The directed differentiation of the embryoid body cells led to hematopoietic precursor cells (5)that were subsequently introduced into a mouse exposed to ionizing radiation (6).

The induced pluripotent stem cells are an excellent model for pathogenetic studies at the celllevel and testing compounds possessing a possible therapeutic effect.

The induced pluripotent stem cells were produced from the fibroblasts of a patient with spinalmuscular atrophy (SMA) (SMAiPSCs). SMA is an autosomalrecessive disease caused by a mutation in the SMN1 ( survival motorneuron 1 ) gene, which is manifested as the selective nonviability of lower motor neurons. Patients with this disorder usually die at the age of about two years.Existing experimental models of this disorder based on the use of flatworms, drosophila, andmice are not satisfactory. The available fibroblast lines from patients withSMA cannot provide the necessary data on the pathogenesis of this disordereither. It was shown that motor neurons produced from SMAiPSCs canretain the features of SMA development, selective neuronal death, and the lackof SMN1 transcription. Moreover, the authors succeeded in elevating the SMNprotein level and aggregation (encoded by the SMN2 gene, whose expressioncan compensate for the shortage in the SMN1 protein) in response to the treatment of motorneurons and astrocytes produced from SMAiPSCs with valproate andtorbomycin [89;]. iPSCs and theirderivatives can serve as objects for pharmacological studies, as has been demonstrated oniPSCs from patients with familial dysautonomia (FDA) [90]. FDA is an inherited autosomal recessive disorder manifested as thedegeneration of sensor and autonomous neurons. This is due to a mutation causing thetissuespecific splicing of the IKBKAP gene, resulting in a decreasein the level of the fulllength IKAP protein. iPSCs were produced fromfibroblasts of patients with FDA. They possessed all features of pluripotent cells. Neuralderivatives produced from these cells had signs of FDA pathogenesis and low levels of thefulllength IKBKAP transcript. The authors studied the effect of threesubstances, kinetin, epigallocatechin gallate, and tocotrienol, on the parameters associatedwith FDA pathogenesis. Only kinetin has been shown to induce an increase in the level offulllength IKBKAP transcript. Prolonged treatment with kinetininduces an increase in the level of neuronal differentiation and expression of peripheralneuronal markers.

Currently, a broad spectrum of iPSCs is produced from patients with variousinherited pathologies and multifactorial disorders, such as Parkinsons disease, Downsyndrome, type 1 diabetes, Duchenne muscular dystrophy, talassemia, etc., whichare often lethal and can scarcely be treated with routine therapy [51, 87, 89, 9194]. The data on iPSCs produced by reprogramming somaticcells from patients with various pathologies are given in the .

Functional categories of M. tuberculosis genes with changed expression level during transition to the NC state

One can confidently state that both iPSCs themselves and their derivativesare potent instruments applicable in biomedicine, cell replacement therapy, pharmacology, andtoxicology. However, the safe application of iPSCbased technologies requires the use ofmethods of iPSCs production and their directed differentiation which minimizeboth the possibility of mutations in cell genomes under in vitro culturingand the probability of malignant transformation of the injected cells. The development ofmethods for human iPSC culturing without the use of animal cells (for instance, the feederlayer of murine fibroblasts) is necessary; they make a viralorigin pathogen transferfrom animals to humans impossible. There is a need for the maximum standardization ofconditions for cell culturing and differentiation.

This study was supported by the Russian Academy of Sciences Presidium ProgramMolecular and Cell Biology.

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Induced Pluripotent Stem Cells: Problems and Advantages ...

Skin Stem Cells Comments Off on Induced Pluripotent Stem Cells: Problems and Advantages … | April 15th, 2022

Somatic stem cells (also called adult stem cells) exist naturally in the body. They are important for growth, healing, and replacing cells that are lost through daily wear and tear.

Stem cells from the blood and bone marrow are routinely used as a treatment for blood-related diseases. However, under natural circumstances somatic stem cells can become only a subset of related cell types. Bone marrow stem cells, for example, differentiate primarily into blood cells. This partial differentiation can be an advantage when you want to produce blood cells; but it is a disadvantage if you're interested in producing an unrelated cell type.

Most types of somatic stem cells are present in low abundance and are difficult to isolate and grow in culture. Isolation of some types could cause considerable tissue or organ damage, as in the heart or brain. Somatic stem cells can be transplanted from donor to patient, but without drugs that suppress the immune system, a patient's immune system will recognize transplanted cells as foreign and attack them.

Therapy involving somatic stem cells is not controversial; however, it is subject to the same ethical considerations that apply to all medical procedures.

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Stem Cell Quick Reference - University of Utah

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Skin cells have been exposed to molecules that reverse their development but still retain their function, creating a kind of stem cell that keeps its original function in the body

By Chen Ly

A fluorescent light micrograph of fibroblast cells from human skin

VSHYUKOVA/SCIENCE PHOTO LIBRARY

Researchers have developed a method that can turn back the biological clock on skin cells by 30 years, creating stem cells from mature ones, which could be used to treat skin conditions in the future.

In 2007, Shinya Yamanaka at Kyoto University in Japan developed a technique that could transform adult skins cells into stem cells by inserting four specialist molecules, dubbed Yamanaka factors, that reverse cell development. It takes around 50 days of exposure to these molecules for normal cells to be reprogrammed into what are known as induced pluripotent stem cells (iPSCs).

When you turn to a cell into an iPSC, you lose the original cell type and its functionality, says Diljeet Gill at the Babraham Institute in Cambridge, UK.

Gill and his colleagues have now devised a technique that uses Yamanaka factors to rejuvenate skin cells without losing their previous functionality.

The researchers collected skin cell samples from three human donors that had an average age of around 50, then exposed these to the Yamanaka factors for just 13 days to partially anti-age the cells. They then removed the Yamanaka factors and left the cells to grow.

As we age, our DNA gets tagged with chemicals, so tracking these markers can help us determine how old our bodies are. This is known as our epigenetic clock. Over time, some of our genes will either turn on or off, the collection of which is known as the transcriptome.

Gill and his team found that the epigenetic clock and transcriptome profiles of the partially reprogrammed cells matched the profiles of skin cells that belonged to people who were 30 years younger.

The rejuvenated cells also functioned like younger ones, too, creating more collagen than those that didnt undergo reprogramming. And when placed onto an artificial wound, the reprogrammed cells moved to close the gap much quicker than the older ones did.

In young people, if you cut yourself, itll take quicker to heal the wound, while it would take me longer to heal, says team member Wolf Reik, also at the Babraham Institute. Its very exciting not only the molecular read-outs that are younger, but the cell also functions more like young cells.

The key advance in this study is that we are now able to substantially rejuvenate cells without changing their identity or functionality, says Reik. In previous studies, you would end up with a stem cell, which is not what youd want for therapy.

The technique may one day be useful in treating skin conditions, such as burns and ulcers. There is also the added bonus that the cells wouldnt be rejected by an individuals body, because they would be their own cells, says Gill.

So far, weve only tested this technique in skin cells. Were excited to see if we can translate it across other cell types, says Gill.

Journal reference: eLife, DOI: 10.7554/eLife.71624

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Anti-ageing technique makes skin cells act 30 years younger - New Scientist

Skin Stem Cells Comments Off on Anti-ageing technique makes skin cells act 30 years younger – New Scientist | April 15th, 2022