Self-assembled, Artificial Viruses for Gene Therapy

Intended for use in gene therapy, artificial viruses efficiently carry genes and drug molecules into tumour cells Friday, 30 May 2008 Viruses are true experts at importing genetic material into the cells of an infected organism. This trait is now being exploited for gene therapy, in which genes are brought into the cells of a patient to treat genetic diseases or genetic defects. Korean researchers have now made an artificial virus. As described in the journal Angewandte Chemie, they have been able to use it to transport both genes and drugs into the interior of cancer cells. Natural viruses are extremely effective at transporting genes into cells for gene therapy; their disadvantage is that they can initiate an immune response or cause cancer. Artificial viruses do not have these side effects, but are not especially effective because their size and shape are very difficult to control — but crucial to their effectiveness. A research team headed by Myongsoo Lee has now developed a new strategy that allows the artificial viruses to maintain a defined form and size. The researchers started with a ribbon-like protein structure (â-sheet) as their template. The protein ribbons organized themselves into a defined threadlike double layer that sets the shape and size. Coupled to the outside are "protein arms" that bind short RNA helices and embed them. If this RNA is made complementary to a specific gene sequence, it can very specifically block the reading of this gene. Known as small interfering RNAs (siRNA), these sequences represent a promising approach to gene therapy.

---

A filament-shaped artificial virus is formed by using a pre-organized supra-molecular nano-ribbon as a template. The artificial virus, which is composed of the nano-ribbon, small interfering RNAs (blue, double-helix shape), and hydrophobic guests (red), is highly efficient in delivering genes and drugs to the inside of cells. Credit: (C) Wiley-VCH 2008, http://dx.doi.org/10.1002/anie.200800266

---

Glucose building blocks on the surfaces of the artificial viruses should improve binding of the artificial virus to the glucose transporters on the surfaces of the target cells. These transporters are present in nearly all mammalian cells. Tumour cells have an especially large number of these transporters. Trials with a line of human cancer cells demonstrated that the artificial viruses very effectively transport an siRNA and block the target gene. In addition, the researchers were able to attach hydrophobic (water repellent) molecules — for demonstration purposes a dye — to the artificial viruses. The dye was transported into the nuclei of tumour cells. This result is particularly interesting because the nucleus is the target for many important antitumor agents. Article: Filamentous Artificial Virus from a Self-Assembled Discrete Nanoribbon Yong-beom Lim, Eunji Lee, You-Rim Yoon, Myeong Sup Lee, Myongsoo Lee Angewandte Chemie International Edition 2008, 47, No. 24, 4525– 4528, doi: 10.1002/anie.200800266 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

First Human Female DNA Sequenced

First Human Female DNA Sequenced Monday, 26 May 2008 Geneticists of Leiden University Medical Centre (LUMC) are the first to determine the DNA sequence of a woman. She is also the first European whose DNA sequence has been determined. Following in-depth analysis, the sequence will be made public, except incidental privacy-sensitive findings. The results will contribute to insights into human genetic diversity. DNA of geneticist Marjolein Kriek The first woman in the world to have her complete DNA sequenced is described as a red-haired, 34-year-old Dutch woman. The DNA is that of Dr. Marjolein Kriek, a clinical geneticist at LUMC, scientists at Leiden University Medical Centre announced on Monday. “If anyone could properly consider the ramifications of knowing his or her sequence, it is a clinical geneticist,” says professor Gert-Jan B van Ommen, leader of the LUMC team and director of the Center for Medical Systems Biology (CMSB), a center of the Netherlands Genomics Initiative. Van Ommen continues: “Moreover, while women don’t have a Y-chromosome, they have two X-chromosomes. As the X-chromosome is present as a single copy in half the population, the males, it has undergone a harsher selection in human evolution. This has made it less variable. We considered that sequencing only males, for ‘completeness’, slows insight into X-chromosome variability. So it was time, after sequencing four males, to balance the genders a bit”. He smiled: “And after Watson we also felt that it was okay to do Kriek”. Eight times coverage The DNA sequencing was done with the Illumina 1G equipment. This was installed in January 2007 in the Leiden Genome Technology Center, the genomics facility of LUMC and CMSB. In total, approx. 22 billion base pairs (the ‘letters’ of the DNA language) were read. That is almost eight times the size of the human genome. Dr. Johan den Dunnen, project leader at the Leiden Genome Technology Center: “This high coverage is needed to prevent mistakes, connect the separate reads and reduces the chance of occasional uncovered gaps.” “The sequencing itself took about six months. Partly since it was run as a ‘side operation’ filling the empty positions on the machine while running other projects. Would such a job be done in one go, it would take just ten weeks”. The cost of the project was approximately €40.000. This does not include further in-depth bioinformatics analysis. This is estimated to take another six months. History of human DNA sequencing In 2001, the DNA sequence was published of a combination of persons. The DNA sequences of Jim Watson, discoverer of the DNA’s double helix structure, followed in 2007, and later the DNA of gene hunter Craig Venter. Recently the completion of the sequences of one Han Chinese individual and two Yoruba-Africans was announced. Bessensap The researchers announced their news at the yearly ‘Bessensap’ meeting, bringing together the Dutch scientists and the press. The Netherlands Organization for Scientific Research NWO organizes this event jointly with the Association of Science Writers VWN and Science Center NEMO. In its eight years of existence, Bessensap has had several high-profile news items. It has had a debate with Italian ‘clonedoctor’ Severino Antinori and hosted dino-hunter Jack Horner, who was key in the Jurassic-Park modelling. During Bessensap also the yearly Eureka prize is awarded for the best popular-scientific book and media production. Leiden University Medical Center Leiden University Medical Center (LUMC) is strongly committed to ongoing improvement in health care quality and intends to play a leading role in this field at both national and international level. Its core activities are research, patient care, education and post graduate training. LUMC is part of the Dutch Federation of University Medical Centers (NFU), which promotes the shared interests of the eight University Medical Centers in the Netherlands. See also: The human genome; you gain some, you lose some Kriek, Marjolein 6-Dec-2007 International Human Genome Project Launched CellNEWS - Wednesday, 23 January 2008 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

How Stem Cells Decide What They Will Become

New evidence supports a 'systems' view – and gives a glimpse at how it works Wednesday, 21 May 2008 How does a stem cell decide what specialized identity to adopt – or simply to remain a stem cell?

A new study suggests that the conventional view, which assumes that cells are “instructed” to progress along prescribed signalling pathways, is too simplistic. Instead, it supports the idea that cells differentiate through the collective behaviour of multiple genes in a network that ultimately leads to just a few endpoints – just as a marble on a hilltop can travel a nearly infinite number of downward paths, only to arrive in the same valley. The findings, published in the May 22 issue of Nature, give a glimpse into how that collective behaviour works, and show that cell populations maintain a built-in variability that nature can harness for change under the right conditions. The findings also help explain why the process of differentiating stem cells into specific lineages in the laboratory has been highly inefficient. Led by Sui Huang, MD, PhD, a Visiting Associate Professor in the Children’s Hospital Boston Vascular Biology Program (now also on the faculty of the University of Calgary), and Hannah Chang, an MD/PhD student in Children’s Vascular Biology Program, the researchers examined how blood stem cells “decide” to become white blood cell progenitors or red blood cell progenitors. They began by examining populations of seemingly identical blood stem cells, and found that a cell marker of “stemness,” a protein called Sca-1, was actually present in highly variable amounts from cell to cell – in fact, they found a 1,000-fold range. One might think that low Sca-1 cells are simply those cells that have spontaneously differentiated. However, when Huang and Chang divided the cells expressing low, medium and high levels of Sca-1 and cultured them, each descendent cell population recapitulated the same broad range of Sca-1 levels over nine days or more, regardless of what levels they started with. “We then asked, are these cells also biologically different?” says Huang, the paper’s senior author. “And it turned out they were dramatically different in differentiation.” Blood stem cells with low levels of Sca-1 differentiated into red blood cell progenitors seven times more often than cells high in Sca-1 when exposed to erythropoietin, a growth factor that promotes red blood cell production. Conversely, when stem cells were exposed to granulocyte–macrophage colony-stimulating factor, which stimulates white blood cell formation, those that were highest in Sca-1 were the most likely to become white cells. Yet, in both experiments, all three groups of cells retained characteristics of stem cells. Huang and Chang then looked at the proteins GATA1 and PU.1, transcription factors that normally favour differentiation into red and white blood cells, respectively. Blood stem cells that were low in Sca-1 (and most prone to become red blood cells) had much more GATA1 than did the high- and medium-Sca-1 cells. Stem cells high in Sca-1 (and least prone to become red blood cells) had the highest levels of PU.1. But most important, the differences in Sca-1, GATA1 and PU.1 levels across the three cell groups became less pronounced over time, as did the variability in the cells’ propensity to differentiate, suggesting that the differences are transient. In a final step, Huang and Chang used microarrays to look at the cells’ entire genome. Again, they found tremendous variability within the apparently uniform cell population: more than 3,900 genes were differentially expressed (turned “on” or “off”) between the low- and high-Sca-1 cells. And again, this variability was dynamic: the differences diminished over time, with gene activity in both the low- and high-Sca-1 cells becoming more like that in the middle group. Together, the findings make the case that a slow fluctuation or cycling of gene activity tends to maintain cells in a stable state, while also priming them to differentiate when conditions are right. “Even if cells are officially genetically identical and belong to the same clone, individual members of that population are quite different at any given time,” says Huang. “This heterogeneity has usually been seen as random ‘measurement noise,’ and, more recently, as ‘gene expression noise.’ But it turns out to be very important, and is the basis for stem cells’ multipotency – their ability to differentiate into multiple lineages.” “Nature has created an incredibly elegant and simple way of creating variability, and maintaining it at a steady level, enabling cells to respond to changes in their environment in a systematic, controlled way,” adds Chang, first author on the paper. Practically speaking, the work suggests that stem cell biologists may need to change their approach to differentiating stem cells in the laboratory for therapeutic applications. “So far the process has been highly inefficient – only 10 to 50 percent of cells respond to the hormone or whatever is given to make them differentiate,” Huang says. “That is because of the cells’ inherent heterogeneity. People have been finding more and more sophisticated stimulator cocktails, but we could make the process more efficient by harnessing the heterogeneity and identifying cells that are already highly poised to differentiate.” Chang has already done follow-up experiments showing that stem cell differentiation can be made dramatically more efficient by choosing the right subpopulation of stem cells and stimulating them promptly, while they are most apt to differentiate. “I’m not doing anything complicated – just using what nature already has,” she says. But the findings also challenge biologists to change how they think about biological processes. The work supports the idea of biological systems moving toward a stable “attractor state,” a concept borrowed from physics. In this case, blood stem cells tend to remain blood stem cells, yet they experience inherent fluctuations in gene activity and protein production that can sometimes be enough to tip the balance and cause them to fall into other attractor states – namely, red or white blood cell progenitors. Specific growth factors can tip the balance, but these factors are part of an overall landscape that guides cells toward different destinies. A marble going downhill will eventually end up in a valley, but which valley it falls into depends on the shape of the landscape.

---

When exposed to a growth factor, a blood stem cell, represented by a blue marble, falls into a new "attractor state," depicted as a valley in a landscape, to become a red blood cell. Different influences, such as differentiation factors, can lead stem cells to the same attractor state, but each cell can take very different paths though the landscape to get there (just as a marble might take a different path each time it rolls down a hill). Credit: Children's Hospital Boston.

---

“Growth or differentiation factors merely increases the probability that a cell will grow or differentiate,” says Donald Ingber, MD, PhD, a co-author on the paper who, with Huang, served as Chang’s mentor on the project. “Cell differentiation is an ensemble property, a collective behaviour, inherent in the system’s architecture and set of regulatory interactions.” A previous study by Huang established, for the first time, that a given cell can exhibit a very different pattern of gene activity from its neighbour, taking a very different path through the landscape, yet end up in the same valley. He and his colleagues exposed precursor cells to two completely different drugs (DMSO and retinoic acid) and closely monitored the cells’ gene expression. Both groups of cells eventually differentiated to become neutrophils (a type of white blood cell), but the molecular paths they took and their patterns of gene expression were completely different until day seven, when they finally converged. The landscape analogy and collective “decision-making” are concepts unfamiliar to biologists, who have tended to focus on single genes acting in linear pathways. This made the work initially difficult to publish, notes Huang. “It’s hard for biologists to move from thinking about single pathways to thinking about a landscape, which is the mathematical manifestation of the entirety of all the possible pathways,” he says. “A single pathway is not a good way to understand a whole process. Our goal has been to understand the driving force behind it.” Reference: Transcriptome-wide noise controls lineage choice in mammalian progenitor cells Hannah H. Chang, Martin Hemberg, Mauricio Barahona, Donald E. Ingber, & Sui Huang Nature 453, 544-547 (22 May 2008), doi:10.1038/nature06965 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

New Light on Stem Cell Self-renewal

Research discovers method to duplicate primitive stem cells and prevent cell differentiation Wednesday, 21 May 2008 Researchers from California (USC), United Kingdom and Canada have discovered a new mechanism to allow embryonic stem cells to divide indefinitely and remain undifferentiated. The study, which will be published in the May 22 issue of the journal Nature, also reveals how embryonic stem cell multiplication is regulated, which may be important in understanding how to control tumour cell growth. “Our study suggests that what we believe about how embryonic stem cell self-renewal is controlled is wrong,” says Qi-Long Ying, Ph.D., assistant professor of Cell and Neurobiology at the Keck School of Medicine of USC, researcher at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, and lead author of the paper. “Our findings will likely change the research direction of many stem cell laboratories.” Contrary to the current understanding of stem cell self-renewal and differentiation, the findings suggest that embryonic stem cells will remain undifferentiated if they are shielded from differentiation signals. By applying small molecules that block the chemicals from activating the differentiation process, the natural default of the cell is to self-renew, or multiply, as generic stem cells. Pluripotent mouse embryonic stem (ES) cells are usually maintained by using various empirical combinations of feeder cells, conditioned media, cytokines, growth factors, hormones, foetal calf serum, and other serum extracts. ES-cell self-renewal has therefore generally been considered to be dependent on stimulation of a multitude of factors in transcriptional control, specially the activation of STAT3 by cytokines. Here the researchers show that external stimuli are dispensable for the derivation, propagation and pluripotency of ES cells. Self-renewal is enabled by the elimination of differentiation-inducing signals from mitogen-activated protein kinase and glycogen synthase kinase 3. Furthermore, isolating ES cells genetically devoid of STAT3 confirmed that the cytokine signalling pathways can be bypassed while self-renewal of the ES cells were maintained. Therefore the researchers conclude that ES cells have an inborn programme for self-replication that does not require extrinsic instructions. “This study presents a completely new paradigm for understanding how to grow embryonic stem cells in the laboratory,” says Martin Pera, Ph.D., director of the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC. “The discovery has major implications for large scale production of specialized cells, such as brain, heart muscle and insulin producing cells, for future therapeutic use.” Embryonic stem cells have only been derived from a very small number of species. “We believe the process we discovered in mice may facilitate the derivation of embryonic stem cells from species like pigs, cows or other large animals, which have not been done before,” continues Ying. “If deriving embryonic stem cells from cows, for instance, is possible, then perhaps in the future cows might be able to produce milk containing medicines.” With better understanding of the multiplication process of embryonic stem cells, researchers have additional insight on tumour cell growth as these cells share similar qualities. “Our study reveals part of the little known process of how embryonic stem cells multiplication is regulated. This is important for us in understanding how to control tumour cell growth moving forward in cancer research,” says Ying. This research was funded by the Medical Research Council and the Biotechnology and Biological Sciences Research Council of the UK, the Canadian Institutes of Health Research, and by the European Commission Framework VI project EuroStemCell. Reference: The ground state of embryonic stem cell self-renewal Qi-Long Ying, Jason Wray, Jennifer Nichols, Laura Batlle-Morera, Bradley Doble, James Woodgett, Philip Cohen & Austin Smith Nature 453, 519-523 (22 May 2008) doi:10.1038/nature06968 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Protein Key To Neuronal Regeneration

Regenerative activity in the peripheral nervous system could mean regeneration for the central nervous system Tuesday, 20 May 2008 Researchers at the Peninsula Medical School in the South West of England, University College London, the San Raffaele Scientific Institute in Milan and Cancer Research UK, have for the first time identified a protein that is key to the regeneration of damage in the peripheral nervous system and which could with further research lead to understanding diseases of our peripheral nervous systems and provide clues to methods of repairing damage in the central nervous system, according to a paper published this week in the Journal of Cell Biology. The team looked at a protein called c-Jun, a transcription factor that regulates the expression of other genes. They found that the c-Jun protein plays a vital role in the regulating the plasticity of Schwann cells which is vital for the way in which the peripheral nervous system regenerates and repairs itself after injury. Schwann cells produce the sheaths that surround and insulate neurons. When there is damage to the peripheral nervous system Schwann cells unwrap themselves from the degenerating axon. During this process of repair, Schwann cells then provide the correct environment for the neurons to re-grow and complete the process of repair. By identifying this transcription factor, the research team believes that there is scope to produce eventual cures for damage and diseases of the peripheral nervous system, such as the inherited condition Charcot-Marie-Tooth disease and the autoimmune disorder Guillain-Barre disease. Unlike the peripheral nervous system, the central nervous system does not regenerate when damaged. With further research, the team hopes to work towards identifying ways in which Schwann cells and c-Jun could be used to repair the spinal cord, leading to possible cures and relief for millions of people around the world suffering from damage of the central nervous system. Further research could also identify whether abnormal activation of the c-Jun protein may be involved in causing Schwann cell tumours, for instance in the condition of neurofibromatosis type 2, leading to a better understanding of this condition and the development of therapies for this condition. Dr. David Parkinson from the Peninsula Medical School, who was lead researcher on the paper, commented: “This is a very exciting first step towards understanding how the peripheral nervous system repairs itself, how that process could be used to produce cures for diseases of and damage to the peripheral nervous system, and how it could ultimately encourage the central nervous system to behave like the peripheral nervous system and repair itself.” “We knew that Schwann cells, unlike other cells in the body, are constantly able to rejuvenate themselves. We now have a better understanding of how this happens, and that understanding could be used to create treatments and therapies for a wide range of degenerative diseases,” he added. References: c-Jun is a negative regulator of myelination David B. Parkinson, Ambily Bhaskaran, Peter Arthur-Farraj, Luke A. Noon, Ashwin Woodhoo, Alison C. Lloyd, M. Laura Feltri, Lawrence Wrabetz, Axel Behrens, Rhona Mirsky, and Kristján R. Jessen The Journal of Cell Biology, Vol. 181, No. 4, 625-637, doi:10.1083/jcb.200803013 Turning back the clock for Schwann cells Mitch Leslie The Journal of Cell Biology, Vol. 181, No. 4, 568, doi:10.1083/jcb.1814iti1 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Gordon Brown Urges Support for Embryo and Stem Cell Research

Gordon Brown urges support for embryo and stem cell research Sunday, 18 May 2008 Scientists should be given the legal framework necessary to pursue cures for diseases like Parkinson's, Alzheimer's and cancer, the British PM Gordon Brown has said. Writing in the Observer newspaper today, Mr Brown said "we owe it to ourselves and future generations" to allow scientists to use properly regulated stem cell research. He said providing clear laws for researchers could save "millions of lives". Adult stem cells are already being used in treatments for conditions including leukaemia and heart disease. Scientists are close to breakthroughs that will allow embryonic stem cells to be used to treat a much wider range of conditions, especially those affecting the brain and nervous system. Mr Brown said that he has "deep respect" for those opposed to the research on religious grounds, and the proposed legal framework has been designed to be as clear as possible. The use of 'human admixed embryos', where human and animal genetic material is used together, will address the shortage of embryonic stem cells, he explained. "Let me be clear: if we want to sustain stem cell research and bring new cures and treatments to millions of people, I believe admixed embryos are necessary. The question for me is not whether they should exist, but how their use should be controlled." Read more: Why I believe stem cell researchers deserve our backing The Observer - Sunday May 18 2008 UK Department of Health Stem Cell pages ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

When Does Human Life Begin?

Inject rational argument into embryo debate, says expert Friday, 16 May 2008 In the week that the UK parliament debates controversial amendments to the 1990 Human Fertilisation and Embryology Act, Professor John Burn asks at what point a cell becomes a human. Prof. Burn is Medical Director of the Institute of Human Genetics at Newcastle University, where some of the most controversial stem cell research takes place. The fact that stem cells have a potential role in the treatment of incurable diseases such as paraplegia and Parkinson's disease means that we should avoid erecting blanket legal barriers, writes Prof. Burn. Concerns about the misuse of funds, threats to the structure of the family, and the dangers of admixed (hybrid) embryos can all be adequately addressed without an act of parliament, he argues. Stem cell research is done in a highly regulated environment, with statutory bodies such as the Human Fertilisation and Embryology Authority (HFEA) having access to the requisite expertise. The authority has already proved its ability to reach reasoned conclusions on similarly touchy subjects. But there is one argument against stem cell research that cannot be addressed by a committee, Prof. Burn says — the question of when human life begins. The Catholic Church’s position is clear: from the moment of conception an embryo is a human being, entitled to full human status. It equates the deliberate generation of embryonic stem cells to murder. Like some of his predecessors, Pope Benedict XVI has declared that “ensoulment” might occur at conception. But, writes Prof. Burn, if souls are delivered, it is difficult to see how this could occur before 14 days. It is only then that the primitive streak forms, and a single embryo could be said to exist. Before this, the cells that make up the embryo could result in up to five identical embryos. The Catholic Church is more supportive of research on adult stem cells, but Prof. Burns says that recent research with induced pluripotent stem cells — adult stem cells which are made to act like embryonic ones — could be regarded as resulting in “instant ensoulment”. Prof. Burn also claims that the tabloid horror of admixed embryos (the cow-human hybrids) is misplaced. Adult stem cells are used, and “admixed embryos use tissue from the abattoir to preserve precious human eggs and advance laboratory research that offers real hope.” “Just as protests about cadaver organ donation were addressed rationally and led to the widespread acceptance that the definition of death could no longer depend on biblical interpretation, so medical need dictates that the origin of human individuality must be defined with similar pragmatic precision. A cell cannot have a soul”, concludes Prof. Burn. Reference: Can a cell have a soul? John Burn BMJ 2008;336:1132 (17 May), doi:10.1136/bmj.39581.436875.94 See also: Does a clone have a ‘soul’? CellNEWS ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Embryonic Pathway Induce Stem Cell Character

Embryonic Pathway Induce Stem Cell Character Thursday, 15 May 2008 Studies of how cancer cells spread have led to a surprising discovery about the creation of cells with adult stem cell characteristics, offering potentially major implications for regenerative medicine and for cancer treatment. Some cancer cells acquire the ability to migrate through the body by re-activating biological programs that have lain dormant since the embryo stage, as the lab of Whitehead Member Robert Weinberg has helped to demonstrate in recent years. Now scientists in the Weinberg lab have shown that both normal and cancer cells that are induced to follow one of these pathways may gain properties of adult stem cells, including the ability to self-renew. In a paper published online by Cell on May 15, former postdoctoral researcher Sendurai Mani and his colleagues demonstrated in mice and in human cells that cells that have undergone an “epithelial-to-mesenchymal” (EMT) transition acquire several important characteristics of stem cells. Conversely, the researchers also showed that naturally existing normal stem cells as well as tumour-seeding cancer stem cells show characteristics of the post-EMT cells, including the acquisition of mesenchymal cell traits, which are usually associated with connective tissue cells. Epithelial cells, which make up most of the human body, bind together in sheet-like structures. In embryonic development, the EMT process breaks up cell-cell adhesion in the epithelial layer, and converts epithelial cells into more loosely associated mesenchymal cells. In the context of cancer development, some cancer cells within a primary cancer may undergo an EMT, migrate through the body to their end destination, and there resume their epithelial form through a reverse process (the mesenchymal-to-epithelial transition).

---

A. Normal human mammary epithelial cells are tightly packed in culture. B. The epithelial-mesenchymal transition (EMT) generates cells that are more loosely associated and offer some traits of adult stem cells.

---

Mani and his colleagues have identified FOXC2, one of the key genes involved in invasion and metastasis. In addition, FOXC2 appears to program the metastatic ability of some breast cancers. Mani knew that during embryonic development, FOXC2 expression is restricted to mesoderm and mesoderm-derived cells when they are in an undifferentiated state, and its expression disappears once these cells differentiate. Similarly, his experiments showed that epithelial cells that undergo EMT express FOXC2, but that expression is lost when they revert back to an epithelial state. In collaboration with Andrea Richardson and Jeffery Kutok, pathologists at Boston’s Brigham and Women’s Hospital, Mani went on to study FOXC2 expression in normal human breast tissue. It turned out that such cells were located precisely where researchers expect to find mammary epithelial stem cells. As he pondered these findings and the earlier results about FOXC2’s role in metastasis, Mani wondered: Just what were these cells generated by EMT that expressed FOXC2" Were they simply fibroblasts, the most common cells in normal connective tissue? Or were they actually stem cells? “I asked Mai-Jing Liao, another postdoc in the Weinberg lab, to check whether the cells generated by EMT would have any stem cell properties,” recalls Mani, now an assistant professor in the department of molecular pathology at the University of Texas’s M. D. Anderson Cancer Center in Houston. “He said, ‘You must be out of your mind, but it won’t take more than half an hour to check.’” Much to Liao’s surprise, when he examined cells that had undergone an EMT, his tests did highlight surface proteins that are key markers for stem cells. The researchers found that the cells that underwent the EMT process were mesenchymal-like in appearance and demonstrated stem-cell surface markers. The cells also displayed an increased ability to grow in suspension, forming structures called mammospheres — another trait of mammary stem cells. Some cells in the resulting mammospheres showed, in turn, stem cell markers, indicating they could differentiate into two kinds of mammary cells. And cells in the mammospheres retained their stem cell properties even after the EMT induction process was stopped.

---

Human mammary epithelial cells that undergo an epithelial-to-mesenchymal transition (EMT) in culture may grow in suspension into structures called mammospheres - a trait they share with mammary epithelial stem cells. Here, the yellow cells present surface proteins indicating that they can develop into more than one type of mammary cell. Credit: Wenjun Guo.

---

Furthermore, when the Weinberg lab scientists isolated stem-cell-like cells from cultured human mammary epithelial cells or from mouse breast tissue, their properties were very similar to the EMT-induced cells. Working with Kornelia Polyak of Dana-Farber Cancer Institute and Harvard Medical School, Mani found that this was also true with normal and tumour cells obtained from human patients. “This for us is a very exciting discovery, not only because of its unexpectedness but because it offers a route by which one could in principle generate unlimited numbers of stem cells committed to create a specific cell type,” says Weinberg, who is also a professor of biology at Massachusetts Institute of Technology. “One could imagine, for example, that if one takes skin cells and induces them to undergo an EMT, they could become skin stem cells.” Importantly, the researchers also demonstrated that inducing the EMT process can produce cells with many characteristics of cancer stem cells. (Beginning in 2003, scientists in various labs has identified these self-renewing, tumour-seeding cells in a number of solid tumours.) This finding could help to answer a key question about metastasis: When tumour cells spread into different sites, how do they multiply enough to form a dangerous new tumour? “If you take a population of human cancer cells that normally form a tumour very inefficiently and induce an EMT, their tumour-initiating abilities increase by about a hundred-fold, so that it takes about 10,000 cells rather than a million cells to form a tumour,” says Wenjun Guo, co-lead author on the paper and postdoctoral researcher in the Weinberg lab. “This suggests cancer stem cells are using pre-existing normal stem cell machinery to propagate their own self-renewal and therefore their tumour-initiating ability.” Mani is continuing his research on the EMT/cancer stem cell connection and its role in cancer metastasis at the M. D. Anderson Cancer Center. Researchers in the Weinberg lab will investigate the EMT process with other cell lines. They also will attempt to give final proof in mice that the process creates completely defined stem cells, by taking cells from mouse mammary fat pads, inducing an EMT for some of the cells, returning the resulting cells to the fat pad, and seeing if they can regenerate the mammary gland. This research was supported by the Breast Cancer Research Foundation, the MIT Ludwig Center for Molecular Oncology and the National Cancer Institute. Mani was supported by a Department of Defence postdoctoral fellowship. Reference: The epithelial-mesenchymal transition generates cells with properties of stem cells Sendurai A. Mani, Wenjun Guo, Mai-Jing Liao, Elinor Ng Eaton, Ayyakkannu Ayyanan, Alicia Zhou, Mary Brooks, Ferenc Reinhard, Cheng Cheng Zhang, Michail Shipitsin, Lauren L. Campbell, Kornelia Polyak, Cathrin Brisken, Jing Yang, Robert A. Weinberg. Cell, Vol 133, 704-715, 16 May 2008 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Help China Earthquake victims!

Help China Earthquake victims! Thursday, 15 May 2008 More than 50,000 people may have died in the earthquake that devastated parts of China on Monday, Chinese state media say. The destruction is massive in the town of Yingxiu in Wenchuan County, Sichuan Province, where Xinhua news agency has reported 7,700 people have perished, near the earthquake's epicenter.

---

---

Some places where you can help:

• International Committee of the Red Cross
• Red Cross appeal
• International Federation of the Red Cross Red Crescent Societies
• World Food Programme
• Unicef
• Médecins Sans Frontières
• Oxfam Hong Kong appeal
• Amity Foundation appeal
• Direct Relief International
• Relief International
• International Relief Teams

......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Study on Attitudes to Stem Cell Research

BBVA Foundation international study on attitudes to stem cell research Wednesday, 14 May 2008 Unlike most scientific and technological advances, which tend to take their place silently in society, biotechnology often finds itself the center of public debate and regulatory attention, due partly to the moral issues posed by many of its applications. In this second BBVA Foundation international study on “Attitudes to Biotechnology” (the first was in 2003), the sample has been enlarged from nine to twelve European countries (Austria, Czech Republic, Germany, Denmark, Spain, France, Ireland, Italy, Netherlands, Poland, United Kingdom and Sweden), with the addition of countries from other continents; namely the United States, Japan and Israel. The selection of countries was informed by both their demographical weight and their variability from the standpoint of religious beliefs and cultural traditions. Information was gathered through 1,500 face-to-face interviews in each country with subjects aged 18 and over (around 22,500 interviewees in all) conducted between April 2007 and February 2008. The design and analysis of the survey were the work of the Department of Social Studies and Public Opinion of the BBVA Foundation. The present study focuses on attitudes towards one biotechnology application: research with embryos for the purpose of obtaining stem cells. In particular, it analyzes how far public opinion is informed about stem cells, expectations and reservations regarding research with embryonic stem cells and differences in support for such research depending on the origin of the embryos used. Attention also goes to the attitudes held on the creation of hybrid embryos for stem cell research. PUBLIC UNDERSTANDING OF THE NATURE OF STEM CELLS The data show that the percentage of the population that admit having heard or read anything about this kind of cell was notably uneven across the survey countries: over 70% had heard or read about stem cells in Sweden and Denmark (86%), and also the United Kingdom, Netherlands and United States (between 70% and 75%); and over 55% in Italy, France, Ireland, Spain, the Czech Republic and Germany: while awareness of stem cells was less than 45% in Poland, Austria, Israel and Japan. As well as information about stem cells, the survey enquired about how far citizens understood the properties of such cells and the procedures used for obtaining them. The results point to a moderate understanding of stem cell properties: surpassing 50% in seven of the fifteen countries, between 40% and 50% in another four and below this threshold in the four remaining (Austria, Poland, Japan and Israel). In contrast, people had a poor understanding about how stem cells are extracted and the consequences for the embryo, with percentages no higher than 30% in the United States, between 15% and 20% in a further six countries and lower still in the remainder. VIEWS ABOUT RESEARCH WITH STEM CELLS In most societies there is a broad consensus around the usefulness of research with few-day-old human embryos in order to obtain stem cells. The mean agreement score with the idea that such research is very useful stood higher than the midpoint (5 on a scale from 0 to 10) in all countries except Austria, and was upwards of 6 points in nine of the fifteen countries, with Denmark and Sweden out in front. But this overall perception of usefulness does not rule out feelings of risk or moral dilemmas. Hence the data show considerable reservations about the risks entailed by researching with human embryos that are a few days old for the purpose of obtaining stem cells. There is general disagreement with the idea that this application poses no serious risks, with mean agreement scores below the midpoint (5) in eleven of the fifteen countries. The citizens perceiving least risk are the Danish and the Dutch, with Austrians, Americans and Japanese lined up at the other extreme. The moral or immoral nature of the application meets with divided opinions among survey countries. The majority view in Austria, Germany, Poland, Japan, Israel and United States is that this kind of research is immoral (mean agreement score above the midpoint on the scale), while those most strongly disagreeing with this supposed immorality are the citizens of Denmark, Spain, the United Kingdom and Italy (mean agreement score below the midpoint). Finally, opinions tend to cluster round the midpoint in the remainder of countries. POSSIBLE MEDICAL BENEFITS Debate and regulations regarding research with embryonic stem cells try to weigh up the medical benefits that may be obtained in future (the end pursued) against the moral reservations felt about this kind of research (the means utilized). When the possible medical benefits deriving from stem cell research are opposed in abstract terms to the rights of the embryo, opinions are divided both between and within countries:

• In Spain, the Czech Republic, Sweden, Denmark, France and the Netherlands, the balance leans to a greater or lesser extent towards the side of medical benefits. Hence the majority agree with the statement that “the medical benefits for many human beings that can perhaps be obtained in the future thanks to research with embryos that are a few days old are much more important than the embryos' rights”.
• In Austria, Ireland, Germany, Poland, the United States, Japan and Israel, the balance inclines more or less (depending on the country) towards the rights of embryos: that is, a majority dissent from the idea that “the medical benefits for many human beings that can perhaps be obtained in the future thanks to research with embryos that are a few days old are much more important than the embryos' rights”.
• Finally, the balance is more centered (mean value of 5) in the United Kingdom and Italy.

When the potential medical benefits are spelled out as treatments for what are seen as serious diseases (Parkinson's, Alzheimer's or diabetes), a majority in all countries declare themselves in favour of such research. The mean agreement with the assertion that “research with stem cells from embryos that are a few days old should be supported as a means of finding effective treatments for diseases such as Parkinson's, Alzheimer's or diabetes as soon as possible” was above the midpoint in every country with the exception of Austria, and exceeded 6 points in nine cases, with Spanish and Czech citizens agreeing most strongly. Besides moral objections, this kind of research meets with other reservations to do with ideas of what is natural or unnatural and concern about interfering with or altering the balance of nature. Citizens in most of the survey countries tended to agree that “research with human embryos that are a few days old is an unacceptable interference into the natural processes of life”, with agreement being firmest in Germany, Austria, Poland and Israel. There is also widespread concern that this kind of research may lead to other more dubious uses. The idea that “allowing research with embryos that are a few days old in order to obtain stem cells for use in medicine will open the door to other morally reprehensible uses” meets with considerable approval even in the countries favourably disposed to this application. The consensus round this view is especially marked in France, Germany and Japan. At the same time, research using embryonic stem cells touches on the moral or ethical framework of each individual, and in this sense moral criterion of religious inspiration is a key explanatory vector. In a context of plural opinions, the data show that the dominant view of the moral condition of the few-day-old human embryo is that it is close or identical to that of a human being. The strictly biological view finds widest support in Denmark and Sweden, where opinions are more equally distributed between those believing it makes no sense to talk about a moral condition of the embryo and those seeing it as close or identical to a human being. This view of the embryo as close or identical to a human is most frequently expressed in countries such as Austria, Germany and the United States. In Spain, opinions are quite sharply divided: 27% state that it makes no sense to talk about the moral condition of an embryo that is a few days old, while 25% take the intermediate position and another 35% see its moral condition as close or identical to that of a human being. ACCEPTANCE OF THE USE OF EMBRYOS DEPENDING ON THEIR ORIGIN Public debate and regulatory attention concerning research with stem cells has recently crystallized around two concrete scenarios: the use of spare embryos left over from fertility treatments and the use of embryos created specifically for biomedical research purposes. Citizens in most survey countries make differing judgments on these two scenarios, with acceptance of the use of spare embryos in all cases greater than that of embryos created for research. In the case of spare embryos, mean scores were in the approval zone in all countries except Austria (4.4) and Japan (4.6), and stood higher than 6 points in Denmark, Sweden, the Czech Republic, the Netherlands and Spain. In the case of embryos created for research, scores tended to range from 4 to 5 points, with support only at all emphatic in the Czech Republic (6.2). The citizens of Spain, Italy, the United Kingdom and Poland expressed marginal approval (just scraping in above 5 points on the scale) while remaining countries were all in the rejection zone. CREATION OF HYBRID EMBRYOS Faced with a shortage of human embryos for use in advancing stem cell research, British scientists have sought official permission to create hybrid embryos. In September 2007, the UK agency regulating embryo research and fertility treatments (Human Fertilization and Embryology Authority) approved the creation of hybrid embryos for the purpose of obtaining stem cells for biomedical research. The technique in question involves the implanting of the nucleus of an adult human cell into the egg of an animal from which the nucleus has been previously extracted. The BBVA Foundation survey also questioned citizens about their attitudes to such advances. The creation of hybrid embryos causes divided reactions both between and within countries. The baseline scenario meets with attitudes of rejection (below 5 on an acceptance scale from 0 to 10) in most of the countries studied. Only in the Czech Republic, Spain, Italy, Israel and Denmark does the mean score approach the midpoint on the scale. The citizens of Poland, France, Austria and Germany are the most critical of this application. Predominant in most countries is the fear that the technique could get out of control and lend itself to dangerous uses. This feeling appears to run deepest in Poland, France, Austria and Israel. A rather different reaction emerges in Denmark, the Netherlands and Sweden, where rejection of the creation of hybrids appears to have less to do with fear, and possibly more to do with perceptions that it is interfering with nature. .........

ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

New Cardiac Progenitor Population Found

New Cardiac Progenitor Population Found Wednesday, 14 May 2008 In a discovery that could one day lead to an understanding of how to regenerate damaged heart tissue, researchers at the University of California, San Diego have found that parent cells involved in embryonic development of the epicardium – the cell layer surrounding the outside of the heart – give rise to three important types of cells with potential for cardiac repair. In a study published online May 14 in advance of publication in the journal Nature, researchers led by Sylvia Evans, Ph.D., professor of pharmacology at the Skaggs School of Pharmacy and Pharmaceutical Sciences and professor of medicine at UC San Diego, discovered in mice that developing embryonic cells that form the epicardium develop into cardiomyocytes, or muscle cells, as well as into connective tissue and vascular support cells of the heart. The UCSD team generated mice which enabled lineage studies of epicardial cells, utilizing a marker for these lineages called a T-box transcription factor, Tbx18. “The surprising finding was that during the earliest stages of development, myocytes are also generated from parent cells within the embryonic epicardium,” said Evans. The Evans lab went on to demonstrate that, in the adult mouse, epicardial cells have lost their earlier embryonic ability to generate cardiomyocytes. “Our findings raise the possibility that if we can restore the ability of adult epicardial cells in mammals to generate cardiomyocytes, it may enhance their future potential for cardiac repair following injury, such as a heart attack,” said co-first author Jody C. Martin of UCSD’s Department of Bioengineering. While the adult mammalian heart has lost this capacity to generate new heart muscle, according to Evans, other investigators have demonstrated that zebrafish can fully regenerate their hearts following injury. This regeneration is associated with migration of Tbx 18-expressing cells to the site of injury, and the new formation of cardiomyocytes. If Tbx18-cell migration is prevented, there is no repair. The UCSD researchers’ findings suggest that one reason that zebrafish can regenerate their hearts may be that adult zebrafish epicardium somehow retains the capacity to generate cardiomyocytes. ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Batten Disease Gene Therapy Shows Promise

Innovative therapy is safe and slows disease progression Tuesday, 13 May 2008 Promising results from a team of New York-Presbyterian Hospital/Weill Cornell Medical Center physician-scientists show that gene therapy is both safe and effective at slowing the progression of Batten disease, or Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL), a rare, genetic, degenerative neurological disorder that usually becomes fatal in children by the age of 8 to 12. The results are published online ahead of print in the May 2008 issue (Vol. 19 No. 5) of Human Gene Therapy. Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL) is an autosomal recessive genetic disorder that causes degeneration of the central nervous system. It is a form of Batten disease, a group of lysosomal storage disease in which a lipofuscin-like material is not broken down and accumulates in neurons, causing cognitive impairment, visual failure, seizures, and progressive deterioration of motor function. The clinical trial found that the procedure – which involves injecting a harmless gene-bearing virus into the brain – was not only safe, but, on the average, significantly slowed the disease progression of the subjects tested. Neurological function was assessed using a rating scale throughout an 18-month follow-up period. "The virus is used as a Trojan horse that houses and then delivers a healthy, functional gene into the cells of the brain," says lead author Dr. Ronald Crystal, chairman of the Department of Genetic Medicine and chief of the Division of Pulmonary and Critical Care Medicine at New York-Presbyterian Hospital/Weill Cornell Medical Center. "The genes are incorporated within the genetic material of the cells, which are then able to produce a protein that is deficient in Batten disease." Dr. Crystal is a world leader and pioneer in the use of gene therapy to treat a number of genetic disorders and diseases. The gene in question – CLN2 – is mutated in children with the disease, causing a deficiency in the enzyme TTP-1, which is responsible for ridding cells of the central nervous system of waste materials. Small organelles within the cell, called lysosomes, become clogged with toxic material within the neurons of the brain. "It's like the garbage man of the cell is not able to do its job," says Dr. Crystal. "The trash keeps getting backed up inside the cell until the cells can no longer function properly and then eventually die throughout the entire brain." When this happens, children with the disease begin exhibiting neurological symptoms, starting around age 4, including impaired muscle coordination (ataxia), involuntary twitching (myoclonus), and speech and developmental disorders. A gradual decline in visual ability follows. Affected children generally become wheelchair-bound by the ages of 4 to 6 years and eventually become bedridden. Because the disease is fatal early in life, there are only about 200 cases of the disease in the world at a given time. Subjects from around the world were carefully selected to take part in the trial. Neurological surgeons from New York-Presbyterian Hospital/Weill Cornell Medical Center, led by Drs. Mark Souweidane and Michael Kaplitt, performed the gene therapy procedure. Six tiny holes were made in the skull of each subject, and then a liquid containing the healthy CLN2 gene, within the harmless adeno-associated virus (AAV), was injected into the brain. "Before now, we had no hope of a therapy for Batten disease, but today we can say that there is some hope," says Dr. Crystal. "These results are not just promising for sufferers of the disease, but suggest that gene therapy can work and should be studied for other neurological disorders. Each gene in our body has the potential to become a target to study for human disease." Reference: Treatment of Late Infantile Neuronal Ceroid Lipofuscinosis with CNS Administration of a Serotype 2 Adeno-associated virus expressing the CLN2 cDNA Stefan Worgall, Dolan Sondhi, Neil R. Hackett, Barry Kosofsky, Minal V. Kekatpure, Nurunisa Neyzi, Jonathan P. Dyke, Douglas Ballon, Linda Heier, Bruce M. Greenwald, Paul Christos, Madhu Mazumdar, Mark M. Souweidane and Michael G. Kaplitt and Ronald G. Crystal Human Gene Therapy, May 2008, Vol. 19 No. 5, DOI: 10.1089/hum.2008.022 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

Genetically Modified Human Embryo Stirs Controversy

Scientists create first GM human embryo 
Tuesday, 13 May 2008 

Researchers at Cornell University in New York have made a breakthrough in genetics by creating the first genetically modified (GM) human embryo. The GM embryo was produced to study how early cells in the embryo develop, but the scientists destroyed it just after five days. Led by Nikica Zaninovic, researchers at Cornell University used a virus to add a gene, a green fluorescent protein, to an embryo left over from assisted reproduction. It is believed to be the first documented genetic modification of a human embryo. 

Zaninovic's achievement was announced at the American Society for Reproductive Medicine annual meeting in 2007, but was only publicized recently when the United Kingdom's reproductive technology regulators reviewed the research. One of the authors of the study said to AP that the work was focused on stem cells. He noted that the researchers used an abnormal embryo that could never have developed into a baby anyway. 

"None of us wants to make designer babies," said Dr. Zev Rosenwaks, director of the Center for Reproductive Medicine and Infertility at New York-Presbyterian/Weill Cornell Medical Center. Dr. Rosenwaks said the research had been approved by a review board at his medical center and been privately financed, so it did not violate federal restrictions on research involving human embryos. 

 Doctors already put foreign genes into people as part of gene therapy to treat diseases. But those genetic changes generally cannot be passed on to future generations because they are made to only certain types of cells in the body, like blood cells or muscle cells. Genetic changes made to an embryo would theoretically be heritable if the embryo became a baby. So far, this has been a no-go area for scientists and medical professionals. 

 The breakthrough has brought with it major concerns. The British regulator, the Human Fertilisation and Embryology Authority (HFEA), has even cautioned that such controversial experiments may lead to "large ethical and public interest issues". However, the HFEA has said that it is preparing for scientists to apply for licences to create GM embryos. 

A paper, published by the authority, states: “The bill has taken away all inhibitions on genetically altering human embryos for research. The Science and Clinical Advances Group [of the HFEA] thought there were large ethical and public interest issues and that these should be referred for debate.” 

 The House of Commons in Britain is about to consider legislation permitting this and other controversial reproductive technologies, such as the creation of chimeras – human-animal hybrid embryos. The first voting on this Bill took place yesterday in the British Parliament. There the MPs voted to allow, with a great majority, the plan to update the human embryology laws to continue to their next Parliamentary stage. The research raises a number of difficult ethical questions. 

Though adding a fluorescent protein was merely a proof-of-principle step, modified embryos could be used to research human diseases. Scientists say embryos wouldn't be allowed to develop for more than a few weeks, much less implanted in a woman and brought to term. If the embryos were allowed to develop, genetic modifications – which would be permanent and passed to future generations – might prevent disease. 

Modifications might also be used for other reasons – physical appearance, intellectual prowess and personality changes – though the necessary science remains hypothetical at this point. Developing such techniques would necessarily involve at this stage trial-and-error and risk-taking with human life.

Let's have that debate:
What do you think CellNEWS readers? 

• Should genetically modified human embryos be used in research, or reproduction? Both? Neither? 
• What would be the advantages or disadvantages? 
• Would it OK to produce ‘designer babies’ in the future, when the technique is perfected? 

Reference: 

Genetic Modification Of Preimplantation Embryos and Embryonic Stem Cells (ESC) by Recombinant Lentiviral Vectors: Efficient and Stable Method for Creating Transgenic Embryos and ESC 

N. Zaninovic, J. Hao, J. Pareja, D. James, S. Rafii, Z. Rosenwaks. 

ASRM 2007 Annual Meeting, Poster session. 

Other Online Resources: 

HFEA 

Center for Genetics and Society 

Human Genetics Alert 

Genetics and Public Policy Center 

......... 

ZenMaster

---

For more on stem cells and cloning, go to CellNEWS 
at http://cellnews-blog.blogspot.com/

---

Embryonic Stem Cells Are Genetically ‘Open’

Embryonic Stem Cells Are Genetically ‘Open’ Monday, 12 May 2008 While it has long been known that embryonic stem cells have the ability to develop into any kind of tissue-specific cells, the exact mechanism as to how this occurs has heretofore not been demonstrated. Now, researchers at the Hebrew University of Jerusalem, NCI at NIH in Bethesda, Maryland, and Canada, have succeeded in graphically revealing this process, resolving a long-standing question as to whether the stem cells achieve their development through selective activation or selective repression of genes. The collaborative research group, which included Dr. Eran Meshorer of the Department of Genetics at the Silberman Institute of Life Sciences at the Hebrew University of Jerusalem, has revealed that the embryonic stem (ES) cells express large proportions of their genome “promiscuously.” This permissive expression includes lineage-specific and tissue-specific genes, non-coding regions of the genome that are normally “silent,” and repetitive sequences in the genome, which comprise the majority of the mammalian genome but are also normally not expressed. When ES cells differentiate into specific cell tissue-types, they undergo global genetic silencing. But until this occurs, the ES cells maintain an open and active genome. This might very well be the secret of their success, since by maintaining this flexibility they maintain their capacity to become any cell type. Once silencing, or genetic repression, occurs, this ability is gone. Thus, one can say that the ES cells stand at the ready until the “last minute” — prepared to engage in selective activation into specific cells — holding “in abeyance” their ability to become any kind of cells at the point and time required. To reveal the process as to how this occurs, the researchers created the first full-mouse genomic platform of DNA microarrays. Microarrays are glass-based chips that allow simultaneous detection of thousands of genes. The microarrays used in the study were not confined to specific genes only but spanned the entire genome. Hundreds of such microarrays were required in the study to cover the entire genome in different time points during stem cell differentiation. It was by observation of these sequences that the researchers were able to establish exactly how and at what point the stem cells developed into specific tissue cells and when the silencing occurs. The project carried out by the researchers appears in the latest issue of the journal Cell Stem Cell. The collaborators in addition to Dr. Meshorer who participated in the project include Tom Misteli, Ron McKay, Stuart Le Grice, Sol Efroni and Kenneth Buetow of the US National Institutes of Health, Thomas Gingeras of Affymetrix Inc. of Santa Clara, Calif., and David Bazett-Jones of The Hospital for Sick Children, Toronto. References: Global Transcription in Pluripotent Embryonic Stem Cells Sol Efroni, Radharani Duttagupta, Jill Cheng, Hesam Dehghani, Daniel J. Hoeppner, Chandravanu Dash, David P. Bazett-Jones, Stuart Le Grice, Ronald D.G. McKay, Kenneth H. Buetow, Thomas R. Gingeras, Tom Misteli, and Eran Meshorer Cell Stem Cell, Vol 2, 437-447, 08 May 2008 Chromatin in pluripotent embryonic stem cells and differentiation Eran Meshorer & Tom Misteli Nature Reviews Molecular Cell Biology 7, 540-546 (July 2006) doi:10.1038/nrm1938 ......... ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---

CIRM Award Funds to Build California Stem Cell Labs

Next big investment in stem cell research in California Wednesday, 07 May 2008 CIRM, Donors and 12 California Institutions Commit $1.1 Billion to Stem Cell Research in California. The governing board of the California Institute for Regenerative Medicine (CIRM), the state’s stem cell agency, voted today to distribute $271 million to 12 institutions to build stem cell research facilities throughout California. The institutions committed an additional $560 million from charitable donations and their internal reserves, bringing the total state-wide investment in new research space to $831 million. This leverage of the state’s stem cell funds was further increased by additional institutional commitments for faculty recruitment packages and other related capital costs. In total, the state funding will have leveraged $1.1 billion in new resources to accelerate the pace toward therapies for patients with chronic and debilitating disease and injury. Investment in research infrastructure to extend California’s state-of-the-art research capacity is a critical part of the agency’s scientific strategic plan to sustain and build California’s global leadership in stem cell research and to accelerate the field as a whole. All the institutions have agreed to expedited construction schedules that will deliver nearly 800,000 square feet of facilities with researchers in the labs within two years. This accelerated schedule should create thousands of construction jobs at a time when the state economy needs them. “This Prop. 71 stem cell research facilities program is one of the largest building programs ever dedicated for a new field of medical science and it will deliver an impact that will be felt world-wide,” commented Robert N. Klein, chairman of the governing board of the state stem cell agency. “As a patient advocate, I am inspired by the amount of leverage California research institutions have contributed from their charitable donors and from their reserves. Their incredible commitment underscores the promise that stem cell research holds for patients suffering from chronic disease and injury.” In a statement issued today, Governor Schwarzenegger said: “This will go a long way toward medical research that could save lives and improve them for people with chronic diseases. But also, this kind of public-private investment in a growing jobs sector is exactly the kind of good news our economy needs right now.” The Major Facilities Grant program was launched in August 2007 as a two-part application process. In the fall, the agency’s Scientific and Medical Research Grants Working Group evaluated the scientific merit of 17 proposals submitted in response to the request for application. On January 16, 2008 the ICOC approved Part 1 of the applications, inviting 12 institutions to advance to the second and final part of the application process. Part 2 of the application focuses on the technical aspects of an applicant’s building program and how the scientific program aligns with the CIRM’s objectives, and why the program represents a good value for California taxpayers’ investment. The review was conducted by the 10-member Scientific and Medical Research Facilities Working Group (Facilities Working Group) made up of real estate experts, patient advocates and the chairman of the ICOC. This meeting was open to the public. “These facilities will house basic and clinical researchers working collaboratively, with stem-cell-specific core labs literally ‘down the hall’ – an arrangement that is instrumental to our ability to accelerate the pace of research toward clinical application” said Dr. Alan Trounson, president of CIRM. “Because of this, we believe these facilities will be an instrumental part of advancing one of CIRM’s primary objectives of helping to speed the delivery of stem-cell based therapies and cures into the clinic and to patients.” CIRM had originally pledged to award $262 million in this round of grants, which would have taken the facilities grants by CIRM to the maximum allowed for “bricks and mortar” under Proposition 71. Today’s total of $271 million results from asking the institutions to breakout costs for scientific equipment, which CIRM routinely funds from the research portion of its bond allocation. This allowed CIRM to supplement its facilities total with $9 million from the research pool. “I was very pleased that the review process allowed us to make complete, thorough and fair evaluations of the applications,” said David Lichtenger, Chair of the CIRM Facilities Working Group (FWG), and President and CEO of Integrated Facilities Solutions (IFS) in Palo Alto. “I was also very encouraged to see that many of the applicants are at the forefront in designing innovative research space that efficiently used open and common areas to foster collaboration and flexibility in use.” “I am thrilled that there appears to be sufficient funds that all 12 proposals can move forward to completion because these facilities should dramatically accelerate the pace of getting new therapies to patients,” said David Serrano Sewell, vice chair of the CIRM FWG and Deputy City Attorney in the San Francisco City Attorney’s Office. The 12 institutions had originally requested $336 million in funding from CIRM. At its April 4 - 5 meeting the FWG scored each proposal on set criteria and then reduced each institution’s request by the percentage their score was below 100. For example, if a proposal received a 92, the institution’s request was reduced by eight percent. That reduced the funding gap from $74 million to $27 million. Moving $9 million of the requests into equipment costs reduced the gap to $18 million. This remaining gap was mitigated by offering institutions the chance to receive their award this summer at a discounted rate, rather than two years from now at completion of the projects as was initially contemplated. Eight institutions decided it was financially advantageous for them to take the award now with a nine percent reduction. This closed the gap and the remaining, relatively new and emerging institutions, could get the full funding recommended by the FWG. “California is at the epicenter of stem cell research,” said Eli Broad, founder of The Eli and Edythe Broad Foundation, which has committed more than $50 million to stem cell research at the Broad Institute for Integrative Biology and Stem Cell Research at USC and the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. “By creating new research centers and attracting the very best scientists from around the world, we will enable the rapid progress of one of the most promising areas of scientific and medical research today. The partnership between public institutions, the state, private foundations and donors demonstrates the unprecedented commitment California is making to stem cell research. The Broad Foundation is pleased to be the largest private donor to stem cell research in California.” "The important thing to me is that stem cells might not only extend life, but also improve the quality of life, as so many people suffer in their later years. But I think stem cells will have applications across the entire life span" stated Lorry Lokey, a donor to Stanford University’s project. Edward Thorp, a donor to the University of California, Irvine project states: "Vivian and I believe that private donations like ours in support of stem cell research at UCI will have a benefit both to our community and to our country that is immeasurably greater than the amount of the gift. Stem cell research promises to transform the treatment of disease and to give us longer, healthier lives. We expect donor support will allow continuing breakthroughs by UCI's stellar research team and that this will be leveraged by attracting many times as much in continuing state support." Ray Dolby, a donor to the University of California San Francisco project stated: “Dagmar and I are very happy to see the ongoing progress of CIRM activities and wish the project continued success." Li Ka-shing, a Hong Kong philanthropist and entrepreneur and donor to the University of California, Berkeley project stated: “When I made a gift to support the establishment of the Li Ka Shing Center for Biomedical and Health Sciences at Berkeley, I was inspired by the passage of Prop. 71 and the promise of significant advances in stem cell research. I am pleased to partner with UC Berkeley and with CIRM to support focused efforts targeting the root causes of some of today's most devastating diseases and translate discoveries into new therapies.”

---

(Press the picture for larger version)

The table above details the amount of funding (in US$) each applicant will receive from CIRM, the donor and institutional funds, the total building cost, the additional funds committed for faculty recruitment and other project costs, and total project costs.

---

Major Facilities Grants The objectives of the CIRM Major Facilities Grant Program are:

• Funding new facilities – and encouraging investments by others in new facilities – that are free of any federal funding so as to allow research and development of therapies based on human embryonic stem cell (hESC) and other stem cell approaches to proceed in California without restrictions imposed by the federal government.
• Developing stem cell research centers that will expand research capacity and capabilities in California while bringing stem cell-related researchers together in a collaborative setting.
• Funding new facilities and improvements where research institutions have determined that existing facilities are inadequate or are lacking altogether and thus pose a challenge to the development of therapies and cures for diseases being addressed at these institutions.

The applications seek funding to establish one of three types of CIRM facilities:

• CIRM Institutes to carry out stem cell research in three categories: basic and discovery stem cell research, preclinical (translational) research, and preclinical development and clinical research. CIRM funding for these projects will be up to $50 million.
• CIRM Centers of Excellence to conduct stem cell research in any two of the three categories listed above. CIRM funding for these project will be up to $25 million.
• CIRM Special Program to conduct specialized stem cell projects in one of the categories listed above. CIRM funding for these project will be up to $10 million.

CIRM Grants Awarded Since the Start: Since April 2006 when the CIRM awarded its first scientific grants under the California Stem Cell Research and Cures Initiative, the Institute has funded 168 grants totalling more than $530 million for investigator-initiated research grants and training to 22 California non-profit and academic institutions.

• The first grants directed $37.5 million for training 169 pre-doctoral, post-doctoral, and clinical fellows at 16 non-profit and academic research institutions.
• In 2007 the ICOC approved 73 Leon J. Thal SEED Grants totalling more than $46 million to bring new ideas and new investigators into the field of human embryonic stem cell (hESC) research;
• 28 Comprehensive Research Grants totalling nearly $72 million to support mature, ongoing studies on hESCs by scientists with a record of accomplishment in the field;
• 17 Shared Research Laboratory Grants totalling more than $50 million;
• 22 New Faculty Awards of more than $54 million to encourage the next generation of clinical and scientific leaders in stem cell research;
• and today’s Major Facilities grants to 12 institutions totalling $271 million.

About CIRM: CIRM was established in 2004 with the passage of Proposition 71, the California Stem Cell Research and Cures Act. The state-wide ballot measure, which provided $3 billion in funding for stem cell research at California universities and research institutions, was overwhelmingly approved by voters, and called for the establishment of an entity to make grants and provide loans for stem cell research, research facilities, and other vital research opportunities. To date, the CIRM governing board has approved 168 research and facility grants totalling more than $530 million, making CIRM the largest source of funding for human embryonic stem cell research in the world. .........

ZenMaster

---

For more on stem cells and cloning, go to CellNEWS at http://cellnews-blog.blogspot.com/ and http://www.geocities.com/giantfideli/index.html

---