CytoTherapeutics Subsidiary Stemcells, Inc. Announces First Direct Isolation of Human Brain Stem Cells
SUNNYVALE, Calif.--/WiredBird P-R News/--Jan. 20, 2000. StemCells, Inc., a wholly owned subsidiary of CytoTherapeutics (Nasdaq:CTII), announced today results which suggest they have succeeded, for the first time, in purifying human brain stem cells directly from brain tissue and have dramatically expanded the number of these cells in simple defined cultures. Nobuko Uchida, Ph.D., leader of the neural stem cell research team at StemCells, Inc., presented the findings at the Keystone Symposium in Keystone, Colorado. StemCells, Inc. is focused on identifying tissue-specific stem cells such as the brain-derived neural stem cell.
Stem cells are rare, undifferentiated cells that can both duplicate themselves ("self-renew") and produce differentiated (functionally specialized) cell types that constitute the various tissues or organ systems of the human body.
"The ability to isolate and culture normal human brain stem cells is a breakthrough that could open the way to utilizing these cells to replace or repair diseased or damaged tissue in a patient with neurological or neurodegenerative disorders," Dr. Uchida said. "Highly purified normal stem cells, which have not been genetically modified with cancer genes to make them grow, may be very suitable for transplantation and may provide a safer and more effective alternative to therapies that are based on cells derived from cancer cells or from an unpurified mix of many different cell types.
The researchers additionally reported that, in animal models, they were able to take these purified and expanded stem cells and transplant them back into intact host brains, where they engraft and grow into functional neuronal and glial cells. As long as seven months later, the transplanted human cells still survived and had migrated to specific functional domains of the host brain, with no sign of tumor formation or adverse effects on the mouse recipients. This finding shows that in some relevant respects, the implanted cells act like normal cells.
"The purification of human neural stem cells that Dr.Uchida and colleagues have achieved is the subject of a "composition of matter" patent, filed by the Company, which we believe places StemCells in a leading intellectual property position in the field," said George Dunbar, Acting President of StemCells, Inc.
Finding and isolating human brain stem cells
Although scientists suspected that the human brain contained stem cells, they had not previously been able to purify the stem cells directly from fresh brain tissue. The reason for this inability, Dr. Uchida explained, could be attributed to technical hurdles of sorting cells from brain tissue, which would have hampered the ability to rapidly identify suitable surface markers on these cells.
Working in collaboration with Drs. Fred Gage (The Salk Institute) and Irving Weissman (Stanford Medical Center), two internationally recognized leaders in stem cell research, the StemCells team was first to succeed in identifying antibodies to surface markers on human brain stem cells. By using an antibody approach and state of the art instrumentation, the scientists were able to purify the stem cells away from other cells in the brain tissue.
Potential applications of isolating human brain stem cells
Neurodegenerative diseases such as Parkinson's and Alzheimer's disease, stroke and epilepsy, affect more than 5 million people in the United States alone, and currently no effective long-term therapies are available. The transplantation of human neural stem cells could potentially provide a way to repair tissue damaged by such diseases and injuries that affect the central nervous system.
The ability to isolate human brain stem cells directly from fresh, uncultured tissue is important for several reasons. First, it provides a source of genetically unmodified, normal stem cells for transplantation that is uncontaminated by other unwanted or diseased cell types. Second, it opens the way to better understanding the properties of these cells and how to possibly manipulate them in order to treat specific diseases. For example, the stem-cell derived neural cultures can be genetically modified to secrete needed proteins for the brain. Finally, the efficient engraftment of these non-transformed normal human stem cells into host mouse brains means that the cell product can be tested for its ability to correct deficiencies, in mouse models, of various human neurological diseases. This technology could also provide a unique animal model for the testing of drugs that act on human brain cells.
CytoTherapeutics is a biotechnology company focused on the discovery, development and commercialization of stem cell-based therapies.
Statements in this press release other than statements of historical facts constitute forward looking statements regarding, among other things, the future business operations of CytoTherapeutics, Inc., or of StemCells, Inc., its wholly-owned subsidiary (collectively, "the Company"). The Company's actual results may vary materially from those contemplated in the forward looking statements due to risks and uncertainties to which the Company is subject, including uncertainties regarding the Company's ability to obtain the capital resources needed to conduct the research, preclinical development and clinical trials necessary for regulatory approvals; the fact that the Company's stem cell technology is at the pre-clinical stage and has not yet led to the development of any proposed product; the uncertainty whether any products that may be generated in the future in the Company's stem cell programs will prove clinically effective and not cause tumors or other side effects; the uncertainty whether the Company will achieve revenues from product sales or become profitable; and others that are described in Exhibit 99 to the Company's Annual Report on Form 10-K entitled "Cautionary Factors Relevant to Forward Looking Statements."
CONTACT: StemCells, Inc.
George Dunbar, Acting President, 408/731-8670
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Media Contact for Stem Cells, Inc:
Laura Hansen, Ph.D., 858/860-0266
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