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Scientists prove that disputed Korean stem cell line comes from an unfertilized egg and not cloning
August 03, 2007Can a genetic signature identify the origin of a human stem cell line? Scientists report that a widely available method for comprehensive genetic analysis can help distinguish the type of human embryo that stem cells come from. The research, to be published online August 2nd by the journal Cell Stem Cell, published by Cell Press, also provides an intriguing new insight into the largest scandal in the history of human stem cell research.
Different methods can be used to make embryonic stem (ES) cells. Human ES cells are typically made from embryos that are donated by couples that have undergone in vitro fertilization as a form of assisted reproduction therapy for infertility. Parthenogenetic ES (pES) cells are derived from embryos created by artificial activation of eggs in the absence of sperm. ES cells generated by somatic nuclear transfer (ntES) are derived from embryos that are created when the nucleus of an egg is replaced by the nucleus from a body cell. Creation of human ntES are pES are of particular interest to researchers as they may provide stem cells that are nearly genetically identical to the donor and, therefore, particularly well suited for customized, rejection-proof cell transplantation therapies.
To better understand the specific genetic recombination events that occur in ES cells derived by these different methods, researchers under the direction of Dr. George Q. Daley of Children's Hospital Boston and the Harvard Stem Cell Institute together with an international set of collaborators completed a thorough genome-wide analysis of five novel pES cells, 30 mouse ntES, as well as the SCNT-hES-1 cell line, the first human ES cell line purportedly generated by Korean scientists using human eggs and somatic cell nuclear transfer. The original paper describing the SCNT-hES-1 cell line was retracted after an investigation by the Seoul National University revealed research misconduct, but the derivation of the cell line was never fully resolved.
The study found that ntES and pES cells have distinct DNA recombination signatures. Those made from parthenogenetic embryos display a telltale genetic pattern close to the center of chromosomes. The results also revealed that the SCNT-hES-1 cell line was not derived by somatic nuclear transfer as was previously claimed. "Our analysis shows that the recombination pattern of SCNT-hES-1 is distinct from that of an ntES line and is consistent with its derivation from a parthenogenetic embryo. Thus, we conclude that the derivation of SCNT-hES-1 represented the first successful isolation of human pES cells," offers Dr. Daley.
The authors conclude that, although there are still significant obstacles to overcome in the generation of pES cells, parthenogenesis is an efficient way of generating embryos and that it may someday be feasible to generate patient-specific pES cells from females. "If careful genetic and functional analysis of tissues derived from human pES cells show them to be safe and effective, then pES cells might represent a favorable source for tissue replacement therapies," says Dr. Daley.
Cell Press
The study found that ntES and pES cells have distinct DNA recombination signatures. Those made from parthenogenetic embryos display a telltale genetic pattern close to the center of chromosomes. The results also revealed that the SCNT-hES-1 cell line was not derived by somatic nuclear transfer as was previously claimed. "Our analysis shows that the recombination pattern of SCNT-hES-1 is distinct from that of an ntES line and is consistent with its derivation from a parthenogenetic embryo. Thus, we conclude that the derivation of SCNT-hES-1 represented the first successful isolation of human pES cells," offers Dr. Daley.
The authors conclude that, although there are still significant obstacles to overcome in the generation of pES cells, parthenogenesis is an efficient way of generating embryos and that it may someday be feasible to generate patient-specific pES cells from females. "If careful genetic and functional analysis of tissues derived from human pES cells show them to be safe and effective, then pES cells might represent a favorable source for tissue replacement therapies," says Dr. Daley.
Cell Press
Stem Cell News and Current Stem Cell Events RSSNC State Is First University in Nation to Offer Canine Bone Marrow Transplants
Dogs suffering from lymphoma will be able to receive the same type of medical treatment as their human counterparts, as North Carolina State University becomes the first university in the nation to offer canine bone marrow transplants in a clinical setting.
Cardiac cell transplant studies show promise in cardiac tissue repair
Two studies published in the current issue of CELL TRANSPLANTATION (17:6) examine the efficacy of transplanting bone marrow cells (BMCs) for the repair of heart tissue.
Stem cell research puts interstate rivalry on hold
Victoria and New South Wales have put aside their competitive interstate rivalry to collaborate on a stem cell research project, as announced by Innovation Minister Gavin Jennings and NSW Minister for Science and Medical Research, Verity Firth, today.
Cell removal technique could lead to cheaper drugs
Researchers at the University of Edinburgh have pioneered a simple way to remove dead cells from cell cultures used to make protein-based drugs, which are increasingly prescribed to treat a range of illnesses.
Bone marrow stem cells may help control inflammatory bowel disease
Massachusetts General Hospital (MGH) investigators have found that infusions of a particular bone marrow stem cell appeared to protect gastrointestinal tissue from autoimmune attack in a mouse model.
Bowel cancer indicator should lead to better treatment
STEM cell scientists have developed a more accurate way of identifying aggressive forms of bowel cancer, which should eventually lead to better treatment and survival rates.
Stem cell indicator for bowel cancer should lead to better survival rates
Stem cell scientists have developed a more accurate way of identifying aggressive forms of bowel cancer, which should eventually lead to better treatment and survival rates. Bowel cancer is the third most common cancer in the UK.
UC Riverside researcher develops novel method to grow human embryonic stem cells
The majority of researchers working with human embryonic stem cells (hESCs) - cells which produce any type of specialized adult cells in the human body - use animal-based materials for culturing the cells. But because these materials are animal-based, they could transmit viruses and other pathogens to the hESCs, making the cells unsuitable for medical use.
Limbs saved by menstrual blood stem cells
Cells obtained from menstrual blood, termed 'endometrial regenerative cells' (ERCs) are capable of restoring blood flow in an animal model of advanced peripheral artery disease.
Protein key to control, growth of blood cells
New research sheds light on the biological events by which stem cells in the bone marrow develop into the broad variety of cells that circulate in the blood. The findings may help improve the success of bone marrow transplants and may lead to better treatments for life-threatening blood diseases.
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