Scientists discover gene that improves the quality of reprogrammed stem cells

Source: Agency for Science, Technology and Research (A*STAR), Singapore
Date: February 8, 2010

Summary:

Scientists from the Genome Institute of Singapore (GIS), a biomedical research institute of the Agency for Science, Technology and Research (A*STAR), have discovered a genetic molecule, called Tbx3, which greatly improves the quality of stem cells that have been reprogrammed from differentiated cells (stem cells reprogrammed from differentiated cells are known as induced pluripotent stem cells or iPS cells). The study was published on 7 February 2010 in the prestigious journal Nature.

Virus-free technique enables scientists to easily make stem cells pluripotent

Source: Stanford University Medical Center
Date: February 7, 2010

Summary:

Tiny circles of DNA are the key to a new and easier way to transform stem cells from human fat into induced pluripotent stem cells for use in regenerative medicine, say scientists at the Stanford University School of Medicine. Unlike other commonly used techniques, the method, which is based on standard molecular biology practices, does not use viruses to introduce genes into the cells or permanently alter a cell's genome.

It is the first example of reprogramming adult cells to pluripotency in this manner, and is hailed by the researchers as a major step toward the use of such cells in humans. They hope that the ease of the technique and its relative safety will smooth its way through the necessary FDA approval process.

The Stanford researchers used the so-called minicircles - rings of DNA about one-half the size of those usually used to reprogram cell - to induce pluripotency in stem cells from human fat. Pluripotent cells can then be induced to become many different specialized cell types. Although the researchers plan to first use these cells to better understand - and perhaps one day treat-human heart disease, induced pluripotent stem cells, or iPS cells, are a starting point for research on many human diseases. The research will be published online Feb. 7 in Nature Methods. Research assistant Fangjun Jia, PhD is the lead author of the work.

Scientists Map Epigenome of Human Stem Cells During Development

Source: Agency for Science, Technology and Research (ASTAR) and The Scripps Research Institute (TSRI)
Date: February 4, 2010

Summary:

Scientists at the Genome Institute of Singapore (GIS) and the Scripps Research Institute (TSRI) led an international effort to build a map that shows in detail how the human genome is modified during embryonic development. This detailed mapping is a significant move towards the success of targeted differentiation of stem cells into specific organs, which is a crucial consideration for stem cell therapy. The study was published in the genomics journal Genome Research on February 4, 2010.

3-D scaffold provides clean, biodegradable structure for stem cell growth

Source:University of Washington
Date: February 2, 2010

Summary:

Medical researchers were shocked to discover that virtually all human embryonic stem cell lines being used in 2005 were contaminated. Animal byproducts used to line Petri dishes had left traces on the human cells. If those cells had been implanted in a human body they likely would have been rejected by the patient's immune system. Even today, with new stem cell lines approved for use in medical research, there remains a risk that these cells will be contaminated in the same way. Most research labs still use animal-based "feeder layers" because it remains the cheapest and most reliable way to get stem cells to multiply.

Materials scientists at the University of Washington have now created an alternative. They built a three-dimensional scaffold out of a natural material that mimics the binding sites for stem cells, allowing the cells to reproduce on a clean, biodegradable structure. Results published in the journal Biomaterials show that human embryonic stem cells grow and multiply readily on the structure.

New Form of Stem Cell Communication Rescues Diseased Neurons

Source: Sanford-Burnham Medical Research Institute
Date: February 1, 2010

Summary:

LA JOLLA, Calif., -- Investigators at Sanford-Burnham Medical Research Institute (Sanford-Burnham, formerly Burnham Institute for Medical Research), the Karolinska Institutet, Beth Israel Deaconess Medical Center (BIDMC), Harvard Medical School and Université Libre de Bruxelles have demonstrated in mouse models that transplanted stems cells, when in direct contact with diseased neurons, send signals through specialized channels that rescue the neurons from death. These direct cell-to-cell connections may also play a role in normal development by laying down the blueprint for more mature electrical connections between neurons and other cells. The research was published in the journal Proceedings of the National Academy of Sciences on February 1.

Novel Theory for Mammalian Stem Cell Regulation

Source: Stowers Institute for Medical Research
Date: January 29, 2010

Summary:

Linheng Li, Ph.D., a Stowers Institute Investigator, together with Hans Clevers, M.D., Ph.D., Director of the Hubrecht Institute in Utrecht, Netherlands, co-authored a prospective review published today by the journal Science that proposes a model of mammalian adult stem cell regulation that may explain how the coexistence of two disparate stem cell states regulates both stem cell maintenance and simultaneously supports rapid tissue regeneration.

Adult stem cells are crucial for physiological tissue renewal and regeneration following injury. Current models assume the existence of a single quiescent (resting) population of stem cells residing in a single niche of a given tissue. The Linheng Li Lab and others have previously reported that primitive blood-forming stem cells can be further separated into quiescent (reserved) and active (primed) sub-populations. Emerging evidence indicates that quiescent and active stem cell sub-populations also co-exist in several tissues — including hair follicle, intestine, bone marrow, and potentially in the neural system — in separate yet adjacent microenvironments. In the review, Dr. Li proposes that quiescent and active stem cell populations have separate but cooperative functional roles.

Making Old Stem Cells Act Young Again

Source: Howard Hughes Medical Institute
Date: January 28, 2010

Summary:

In virtually every part of the body, stem cells stand ready to replenish mature cells lost to wounds, disease, and everyday wear and tear. But like other cells, stem cells eventually lose their normal functions as they age, leaving the body less able to repair itself. Surprisingly, this age-related decline in stem cell potency may be somewhat reversible. A team of Howard Hughes Medical Institute (HHMI) researchers has found that in old mice, a several-week exposure to the blood of young mice causes their bone marrow stem cells to act “young” again.

The researchers have not yet isolated the blood-borne factors that can switch old stem cells back to a more youthful state, but their results are consistent with other recent studies that show stem-cell aging may be reversible. Together those results suggest that it might one day be possible to boost the practical lifespan of stem cells, and thereby increase the body’s resistance to disease and age-related degeneration. The new findings are reported in an advanced online publication in Nature on January 28, 2010.

Stem Cell Breakthrough: Bone Marrow Cells Are the Answer

Source: Federation of American Societies for Experimental Biology
Date: January 28, 2010

Summary:

Using cells from mice, scientists discovered a new strategy for making embryonic stem cell transplants less likely to be rejected by a recipient's immune system. This strategy involves fusing bone marrow cells to embryonic stem cells. Once fused, hybrid cells have DNA from both donor and recipient, raising hopes that immune rejection of embryonic stem cell therapies can be avoided without drugs. This strategy, described in a new research report appearing in the February 2010 print issue of The FASEB Journal, involves fusing bone marrow cells to embryonic stem cells.

Research provides insight into the reprogramming of cell fate

Source: The Babraham Institute
Date: 27 January 2010

Summary:

A discovery by Babraham scientists brings new insight into how cells are reprogrammed and a greater understanding of how the environment, or factors like nutritional signals, can interact with our genes to affect health. As an embryo develops, cells acquire a particular fate, for example becoming a nerve or skin cell. The findings, reported online in the journal Nature, pinpoint a protein called AID as being important for complete cellular reprogramming in mammals. In addition, these findings may advance the field of regenerative medicine, by potentially enhancing our ability to guide the reversal of cell fate, and pave the way for novel therapeutics.

Researchers directly turn mouse skin cells into neurons, skipping IPS stage

Source: Stanford University
Date: January 27, 2010

Summary:

Even Superman needed to retire to a phone booth for a quick change. But now scientists at the Stanford University School of Medicine have succeeded in the ultimate switch: transforming mouse skin cells in a laboratory dish directly into functional nerve cells with the application of just three genes. The cells make the change without first becoming a pluripotent type of stem cell — a step long thought to be required for cells to acquire new identities. The finding, published online Jan. 27 in Nature, could revolutionize the future of human stem cell therapy and recast our understanding of how cells choose and maintain their specialties in the body.

Targeting cancer stem cells in the lab

Source: Oxford University
Date: 26 January 2010

Summary:

Understanding of the particular cancer cells within a tumour that drive its growth could now advance more rapidly, thanks to Oxford University scientists. They show in the journal PNAS how a crucial class of cancer cell, called cancer stem cells, can be investigated in the lab in ways that should greatly speed their study, and allow the development of drugs targeted against them.

Scientists find survival factor for keeping nerve cells healthy

Source: Babraham Institute
Date: 26 January 2010

Summary:

Scientists at the Babraham Institute have discovered a novel survival factor whose rapid transport along nerve cells is crucial for keeping them alive. The same factor seems likely to be needed to keep our nerves healthy as we age. These findings, published today in the online, open-access journal PLoS Biology, show that a molecule known as Nmnat2 provides a protective function; in its absence healthy, uninjured nerve cells start to degenerate and boosting levels of Nmnat2 can delay degeneration when the cells are injured. This suggests an exciting new therapeutic avenue for protecting nerves from disease and injury-induced degeneration.

Experimental Stem Cell Treatment Arrests Acute Lung Injury in Mice, Study Shows

Source: University of Texas Health Science Center at Houston
Date: January 25, 2010

Summary:

HOUSTON -- Stem cell researchers exploring a new approach for the care of respiratory diseases report that an experimental treatment involving transplantable lung cells was associated with improved outcomes in tests on mice with acute lung injury. The lung cells were derived from human embryonic stem cells (hESCs). Findings by investigators at The University of Texas Health Science Center at Houston are scheduled to appear in the March issue of Molecular Therapy.

Scientists shed new light on walking

Source: Karolinska Institutet
Date: 22 January 2010

Summary:

Researchers at the medical university Karolinska Institutet have created a genetically modified mouse in which certain neurons can be activated by blue light. Shining blue light on brainstems or spinal cords isolated from these mice produces walking-like motor activity. The findings, which are published in the scientific journal Nature Neuroscience, are of potential significance to the recovery of walking after spinal cord injury.

New Concoction Reprograms Differentiated Cells Into Pluripotent Stem Cells

Source: Agency for Science, Technology and Research (A*STAR)
Date: January 22, 2010

Summary:

Scientists from the Genome Institute of Singapore (GIS), a biomedical research institute of the Agency for Science, Technology and Research (A*STAR), and the National University of Singapore (NUS), have discovered a transcription factor, known as Nr5a2, which is responsible for the reprogramming of differentiated cells into stem cells. Stem cells generated from differentiated cells are known as induced pluripotent stem cells (iPS cells). This find, published on January 21, 2010 in the prestigious journal Cell Stem Cell, is especially crucial in the area of cell therapy-based medicine.

New Way to Generate Abundant Functional Blood Vessel Cells From Human Stem Cells Discovered

Source: Weill Cornell Medical College
Date: January 20, 2010

Summary:

NEW YORK (Jan. 20, 2010) — In a significant step toward restoring healthy blood circulation to treat a variety of diseases, a team of scientists at Weill Cornell Medical College has developed a new technique and described a novel mechanism for turning human embryonic and pluripotent stem cells into plentiful, functional endothelial cells, which are critical to the formation of blood vessels. Endothelial cells form the interior "lining" of all blood vessels and are the main component of capillaries, the smallest and most abundant vessels. In the near future, the researchers believe, it will be possible to inject these cells into humans to heal damaged organs and tissues.

The new approach allows scientists to generate virtually unlimited quantities of durable endothelial cells — more than 40-fold the quantity possible with previous approaches. Based on insights into the genetic mechanisms that regulate how embryonic stem cells form vascular endothelial cells, the approach may also yield new ways to study genetically inherited vascular diseases. The study appears in the advance online issue of Nature Biotechnology.

Stem Cells Become Functioning Neurons in Mice

Source: HealthDay News
Date: January. 19, 2010

Summary:

HealthDay News reports researchers have enabled neurons grown from embryonic stem cells to form propper connections in mice:

Transplanted neurons grown from embryonic stem cells were able to form proper brain connections in newborn mice, U.S. scientists report. Researchers from Stanford Medical School say their study was the first to show that stem cells can be directed to become specific brain cells and to link correctly in the brain. The findings, they say, could help in efforts to develop new treatments for spinal cord injuries and nervous system diseases such as amyotrophic lateral sclerosis, or ALS, also called Lou Gehrig's disease.

“Jekyll and Hyde” cell may hold key to muscular dystrophy, fibrosis treatment: UBC research

Source:University of British Columbia
Date: January 18, 2010

Summary:

A team of University of British Columbia researchers has identified fat-producing cells that possess “dual-personalities” and may further the development of treatments for muscle diseases such as muscular dystrophy and fibrosis. The team found a new type of fibro/adipogenic progenitors, or FAPs, that generate fatty fibrous tissues when transplanted into damaged muscles in mice. Progenitors are similar to stem cells in their capacity to differentiate, but are limited in the number of times they can divide. The findings are published in the current issue of Nature Cell Biology.

Discovery may aid transplantation and regenerative medicine

Source: The Babraham Institute
Date: 18 January 2010

Summary:

Research from the Babraham Institute, reported in the Journal of Experimental Medicine, provides new insights into how our immune system produces T cells, a type of white blood cell that is an essential part of the body's immune surveillance system for fighting infection. The findings pave the way for a new means of making purified T cells, which gets over one of many hurdles faced in the use of T cells in regenerative medicine and transplantations, and in addition will open up new avenues of research and applications in drug and toxicity testing in industry.

Scientists identify molecule that inhibits stem cell differentiation

Source: Stanford University
Date: January 17, 2010

Summary:

Like as not, the recent holidays probably included some reminiscing about family history. There may even have been some remonstrations and recommendations from well-meaning elders to younger kin about their lives’ paths. It turns out stem cells have a similar need for long-term memory to help them know who they are and what they should become. Scientists at the Stanford University School of Medicine have now identified a molecule involved in keeping skin stem cells on the straight and narrow. The molecule, called DNMT1, helps the stem cells know whether to self-renew to create more stem cells, or to differentiate into specialized, non-dividing adult skin cells. It’s important because too much self-renewal can lead to cancer, and too little can inhibit wound healing.

First successful use of expanded umbilical-cord blood units to treat leukemia

Source: Fred Hutchinson Cancer Research Center
Date: January 17, 2010

Summary:

SEATTLE – Scientists at Fred Hutchinson Cancer Research Center have cleared a major technical hurdle to making umbilical-cord-blood transplants a more widely-used method for treating leukemia and other blood cancers. In a study published in the Jan.17 edition of Nature Medicine, Colleen Delaney, M.D., and colleagues describe the first use of a method to vastly expand the number of stem/progenitor cells from a unit of cord blood in the laboratory that were then infused into patients resulting in successful and rapid engraftment.

Growing Replacement Bone: Study Shows that Delivering Stem Cells Improves Repair of Major Bone Injuries

Source: Georgia Institute of Technology
Date: January 11, 2010


A study published this week reinforces the potential value of stem cells in repairing major injuries involving the loss of bone structure. Georgia Tech mechanical engineering professor Robert Guldberg displays a histological image showing cellular bone and cartilage regeneration integrated with a scaffold that was implanted into a large bone defect. The study shows that delivering stem cells on a polymer scaffold to treat large areas of missing bone leads to improved bone formation and better mechanical properties compared to treatment with the scaffold alone. This type of therapeutic treatment could be a potential alternative to bone grafting operations. Details of the research were published in the early edition of the journal Proceedings of the National Academy of Sciences on January 11, 2010.

Biologists Develop Efficient Genetic Modification of Human Embryonic Stem Cells

Source: University of California - San Diego
Date: January 7, 2010

Summary:

Biologists at the University of California, San Diego have developed an efficient way to genetically modify human embryonic stem cells. Their approach, which uses bacterial artificial chromosomes to swap in defective copies of genes, will make possible the rapid development of stem cell lines that can both serve as models for human genetic diseases and as testbeds on which to screen potential treatments. The technique is described in the January 8 issue of the journal Cell Stem Cell.

Enzyme Necessary for Healthy Immune System, Study Finds

Source; University of California - Los Angeles
Date: January 6, 2010

Summary:

Mice without the deoxycytidine kinase (dCK) enzyme have defects in their adaptive immune system, producing very low levels of both T and B lymphocytes, the major players involved in immune response, according to a study by researchers with UCLA's Jonsson Comprehensive Cancer Center.

The finding could have ramifications in treating auto-immune disorders, in which the body attacks itself, and possibly certain cancers of the immune system. A drug could be developed to create lower levels of dCK in the body, thereby tamping down immune response. Such a drug might also be effective in transplant patients to decrease risk for rejection, said Dr. Caius Radu, an assistant professor of Molecular and Medical Pharmacology, a Jonsson Cancer Center researcher and senior author of the study.

The study, part of a long-term research project that has resulted in the development of a new probe for Positron Emission Tomography (PET) scanning and the creation of a non-invasive approach to observe chemotherapy at work in the body, appears this week in the early online edition of the Proceedings of the National Academy of Sciences.

Giving Cells a Fresh Start: Enzyme Wipes Developmental Slate Clean

Source: Howard Hughes Medical Institute
Date: January 6, 2010

Summary:

Howard Hughes Medical Institute (HHMI) researchers and their colleagues have identified an enzyme that can effectively wipe a cell’s developmental slate clean, essentially giving a fresh start. The enzyme, which is thought to help genetically reprogram fertilized eggs as part of normal development, may help scientists create stem cells and arrest the growth of cancers.

The new research, reported in an online article in the journal Nature on January 6, 2010, represents a collaborative effort of scientists from the laboratories of HHMI investigator Yi Zhang at the University of North Carolina, Chapel Hill, and Teruhiko Wakayama at the Center for Developmental Biology in Kobe, Japan. Coauthors of the article are Yuki Okada and Kwonho Hong, postdoctoral researchers in Zhang’s lab, and Kazuo Yamagata of the Wakayama lab.

Study identifies a protein complex possibly crucial for triggering embryo development

Source: University of North Carolina School of Medicine
Date: January 6, 2010

Summary:

Researchers at the UNC School of Medicine have have discovered a protein complex that appears to play a significant role in erasing epigenetic instructions on sperm DNA, essentially creating a blank slate for the different cell types of a new embryo to develop. The protein complex – called elongator – could prove valuable for changing cell fate, such as converting cancer cells to normal cells, as it may be able to reactivate tumor suppressor genes by removing the epigenetic modifications that often prevent them from curbing the proliferation of cancer cells. The discovery may also have implications for stem cell research by providing a tool to quickly reprogram adult cells to possess the same attributes as embryonic stem cells, but without the ethical or safety issues of cells currently used for such studies. The results of the study appear on-line in the Jan. 6, 2010 issue of the journal Nature.

Scripps research team develops technique to determine ethnic origin of stem cell lines

Source: Scripps Research Institute
Date: December 29, 2009

Summary:

An international team of scientists led by researchers at The Scripps Research Institute has developed a straightforward technique to determine the ethnic origin of stem cells. The Scripps Research scientists initiated the study—published in the January 2010 edition of the prestigious journal Nature Methods—because the availability of genetically diverse cell lines for cell replacement therapy and drug development could have important medical consequences. Research has shown that discordance between the ethnic origin of organ donors and recipients can influence medical outcomes for tissue transplantation, and that the safety and effectiveness of specific drugs can vary widely depending on ethnic background.

Chemotherapy-induced heart damage reversed in rats

Source: American Heart Association
Date: December 28, 2009

Summary:

DALLAS, — Heart tissue damage from chemotherapy drugs was reversed in rats by using their own cardiac stem cells (CSCs) that weren’t exposed to the cancer treatment. These cells reversed heart failure, according to a new study in Circulation: Journal of the American Heart Association. The early-stage research will lead to studying humans exposed to a class of chemotherapy drugs called anthracyclines, which is very effective in treating certain types of cancers.

Vitamin C boosts the reprogramming of adult cells into stem cells

Source: Cell Press
Date: December 24, 2009

Summary:

Famous for its antioxidant properties and role in tissue repair, vitamin C is touted as beneficial for illnesses ranging from the common cold to cancer and perhaps even for slowing the aging process. Now, a study published online on December 24th by Cell Press in the journal Cell Stem Cell uncovers an unexpected new role for this natural compound: facilitating the generation of embryonic-like stem cells from adult cells.

Below is additional coverage of this finding:

HealthDay News

Daily Telegraph

Press Association

Scientific American

Tandem Autologous-Allogeneic Stem Cell Transplants Highly Effective for Relapsed Follicular Lymphoma

Source: Cancer Consultants
Date: December 24, 2009

Summary:

Researchers from Canada have reported that autologous stem cell transplantation (SCT) followed by a sibling reduced-intensity allogeneic SCT results in progression-free (PFS) and overall survival (OS) of 96% at three and five years in patients with relapsed follicular lymphoma (FL). The details of this study were presented at the 2009 meeting of the American Society of Hematology (ASH) in New Orleans in the first week of December.[1]

Stanford scientists identify protein that keeps stem cells poised for action

Source: Stanford University Medical Center
Date: December 24, 2009

Summary:

STANFORD, Calif. — Like a child awaiting the arrival of Christmas, embryonic stem cells exist in a state of permanent anticipation. They must balance the ability to quickly become more specialized cell types with the cellular chaos that could occur should they act too early (stop shaking those presents, kids!). Researchers at the Stanford University School of Medicine have now identified a critical component, called Jarid2, of this delicate balancing act — one that both recruits other regulatory proteins to genes important in differentiation and also modulates their activity to keep them in a state of ongoing readiness.

"Understanding how only the relevant genes are targeted and remain poised for action is a hot topic in embryonic stem cell research," said Joanna Wysocka, PhD, assistant professor of developmental biology and of chemical and systems biology. "Our results shed light on both these questions." Wysocka is the lead author of the research, which will be published in the Dec. 24 issue of Cell.

Study shows immune system protein involved in reprogramming adult cells to express stem cell genes

Source: Stanford University Medical Center
Date: December 22, 2009

Summary:

Scientists have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. Scientists believe there is much promise for induced pluripotent stem cells: normal adult cells that have been manipulated to develop the stem-cell-like ability to differentiate into other types of cells, potentially to be used to repair damaged tissue and treat the ravages of disease.

But making these so-called iPS cells is both time-consuming and inefficient. Now researchers at Stanford’s School of Medicine have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. The finding could eliminate a major bottleneck in the generation of iPS and embryonic stem cells — that of removing molecular tags called methyl groups from specific regions of cellular DNA. Without this process of demethylation, the stem cell genes are silent in adult, or differentiated, cells. The research is published online in the Dec. 21 issue of Nature.

Growing Blood Vessels: Bioengineered Materials Promote the Growth of Functional Vasculature, New Study Shows

Source: Georgia Institute of Technology Research News
Date: December 21, 2009

Summary:

Regenerative medicine therapies often require the growth of functional, stable blood vessels at the site of an injury. Using synthetic polymers called hydrogels, researchers at the Georgia Institute of Technology have been able to induce significant vasculature growth in areas of damaged tissue.

Details of the research were published in the early edition of the journal Proceedings of the National Academy of Sciences on December 21, 2009. The work was supported by the National Institutes of Health, the Atlanta Clinical and Translational Science Institute (ACTSI) through the Georgia Tech/Emory Center (GTEC) for the Engineering of Living Tissues, the Juvenile Diabetes Research Foundation, and the American Heart Association.

NEURALSTEM RECEIVES APPROVAL TO COMMENCE FIRST ALS STEM CELL TRIAL AT EMORY ALS CENTER

Source: Neuralstem, Inc.
Date: December 18, 2009

Summary:

ROCKVILLE, Maryland -- Neuralstem, Inc. today announced that its Phase I trial to treat Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig’s disease) with its spinal cord stem cells has been approved by the Institutional Review Board (IRB) at Emory University in Atlanta, GA. The trial, which was approved by the FDA in September, will take place at the Emory ALS Center, under the direction of Dr. Jonathan Glass M.D., Director of the Emory ALS Center, who will serve as the site Principal Investigator (PI). The trial will study the safety of Neuralstem’s cells and the surgical procedures and devices required for multiple injections of Neuralstem’s cells directly into the grey matter of the spinal cord. The Emory ALS Center has posted the relevant trial information for patients on its website.

Umbilical Cord Could Be New Source of Plentiful Stem Cells

Source: University of Pittsburgh
Date: December 17, 2009

Summary:

PITTSBURGH, Dec. 17, 2009 – Stem cells that could one day provide therapeutic options for muscle and bone disorders can be easily harvested from the tissue of the umbilical cord, just as the blood that goes through it provides precursor cells to treat some blood disorders, said University of Pittsburgh School of Medicine researchers in the online version of the Journal of Biomedicine and Biotechnology.

Stem-cell activators switch function, repress mature cells

Source: Ohio State University Medical Center
Date: December 16, 2009

Summary:

In a developing animal, stem cells proliferate and differentiate to form the organs needed for life. A new study shows how a crucial step in this process happens and how a reversal of that step contributes to cancer. The study, led by researchers at the Ohio State University Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, shows for the first time that three proteins, called E2f1, E2f2 and E2f3, play a key role in the transition stem cells make to their final, differentiated, state.

These proteins help stimulate stem cells to grow and proliferate. But once stem cells begin to differentiate into their final cell type - a cell in the retina or in the lining of the intestine, for example - the same three proteins switch function and stop them from dividing any more. The research also shows how these proteins can switch course yet again in cells that have mutations in the retinoblastoma (Rb) gene. Mutated Rb genes occur in many types of cancer, suggesting that these E2f proteins might offer a safe and novel therapeutic target in these tumors. The findings are published in back-to-back papers in the Dec. 17 issue of the journal Nature.

Marking Tissue-Specific Genes in Embryonic Stem Cells Crucial to Ensure Proper Function

Source: University of California - Los Angeles
Date: December 15, 2009

Summary:

Tissue-specific genes, thought to be dormant or not marked for activation in embryonic stem cells, are indeed marked by transcription factors, with proper marking potentially crucial for the function of tissues derived from stem cells.
The finding in the study by researchers at the Broad Stem Cell Research Center involves a class of genes whose properties previously were thought to be unimportant for stem cell function. Most research has instead focused on genes that regulate a pluripotency network and genes that regulate differentiation of embryonic stem cells into other cell lineages.
The Broad center researchers focused on a third class of genes, those expressed only in defined cell types or tissues, which generally remain silent until long after embryonic stem cells have differentiated into specific cell lineages. The study is published in the Dec. 15, 2009 issue of the peer-reviewed journal Genes and Development.

How Do Salamanders Grow a New Leg? Protein Mechanisms Behind Limb Regeneration

Source: Indiana University School of Medicine
Date:December 15, 2009

Summary:

The most comprehensive study to date of the proteins in a species of salamander that can regrow appendages may provide important clues to how similar regeneration could be induced in humans. Researchers at the School of Science at Indiana University-Purdue University Indianapolis and colleagues investigated over three hundred proteins in the amputated limbs of axolotls, a type of salamander that has the unique natural ability to regenerate appendages from any level of amputation, with the hope that this knowledge will contribute to a better understanding of the mechanisms that allow limbs to regenerate. Findings were published online in the journal Biomedical Central Biology on November 30 (BMC Biology 7:83, 2009).

Hebrew University, American researchers identify genetic ‘trigger’ for stem cell differentiation

Source: The Hebrew University of Jerusalem
Date: 9 December 2009

Summary:

A gene which is essential for stem cells’ capabilities to become any cell type has been identified by researchers at the Hebrew University of Jerusalem and the University of California, San Francisco. The discovery represents a further step in the ever-expanding field of understanding the ways in which stem cells develop into specific cells, a necessary prelude towards the use of stem cell therapy as a means to reverse the consequences of disease and disability.

In their current study, which was published recently in the journal Nature, the researchers from the Hebrew University and UCSF showed, using mouse ES cells, that Chd1 regulates open chromatin in ES cells. The open chromatin conformation, maintained by Chd1, enabled the expression of a wide variety of genes, leading to proper differentiation into all types of specific cells. Depletion of Chd1 in embryonic stem cells led to formation of heterochromatin (closed chromatin) and prevented the ability of the cells to generate all types of tissues.

Newly Discovered Mechanism Allows Cells to Change State

Source: Brown University
Date: December 9, 2009

Summary:

Cells are not static. They can transform themselves over time — but change can have dangerous implications. Benign cells, for example, can suddenly change into cancerous ones. That’s one reason why scientists are trying to figure out why and how cells can shed their old identity and take on a new one. If they can figure out how this happens, researchers may better understand why many different cells — such as stem cells or cells that become cancerous — transform. That, in turn, could someday allow scientists to control the transformative process in a way that might help treat a wide range of diseases.

Jeffrey Laney, assistant professor of biology at Brown University, has identified one way this change takes place by looking at Saccharomyces cerevisae, a common yeast used to make beer and bread. Laney found that a cellular “machine” removes a regulatory “lid” from genes in the cell, so the cell can change its state. Details are published online in Nature Cell Biology, with a print version to come.

Mini Transplant May Reverse Severe Sickle Cell Disease

Source: Johns Hopkins Medical Institutions
Date: December 9, 2009

Summary:

Results of a preliminary study by scientists at the National Institutes of Health and Johns Hopkins show that "mini" stem cell transplantation may safely reverse severe sickle cell disease in adults. The phase I/II study to establish safety of the procedure, published Dec. 10 in the New England Journal of Medicine, describes 10 patients with severe sickle cell disease who received intravenous transplants of blood-forming stem cells. The transplanted stem cells came from the peripheral blood of healthy related donors matched to the patients' tissue types. Using this procedure, nine of 10 patients treated have normal red blood cells and reversal of organ damage caused by the disease.

Umbilical Stem Cells May Help Recover Lost Vision for Those With Corneal Disease

Source: University of Cincinnati Academic Health Center
December 8, 2009

Summary:

New research from the University of Cincinnati may help in the recovery of lost vision for patients with corneal scarring. Winston Whei-Yang Kao, PhD, professor of ophthalmology, along with other researchers in UC’s ophthalmology department found that transplanting human umbilical mesenchymal stem cells into mouse models that lack the protein lumican restored the transparency of cloudy and thin corneas. Mesenchymal stem cells are “multi-potent” stem cells that can differentiate into a variety of cell types. These findings are being presented Dec. 8 in San Diego at the 49th Annual Meeting of the American Society of Cell Biology.

New Skin Stem Cells Surprisingly Similar to Those Found in Embryos

Source: Howard Hughes Medical Institute
Date: December 8, 2009

Summary:

Scientists have discovered a new type of stem cell in the skin that acts surprisingly like certain stem cells found in embryos: both can generate fat, bone, cartilage, and even nerve cells. These newly-described dermal stem cells may one day prove useful for treating neurological disorders and persistent wounds, such as diabetic ulcers, says Freda Miller, a Howard Hughes Medical Institute international research scholar.

Miller and her colleagues first saw the cells several years ago in both rodents and people, but only now confirmed that the cells are stem cells. Like other stem cells, these cell scan self-renew and, under the right conditions, they can grow into the cell types that constitute the skin’s dermal layer, which lies under the surface epidermal layer. “We showed that these cells are, in fact, the real thing,” says Miller, a professor at the University of Toronto and a senior scientist in the department of developmental biology at the Hospital for Sick Children in Toronto. The dermal stem cells also appear tohelp form the basis for hair growth.The new work was published December 4, 2009, in the journal Cell Stem Cell.