To all - text of that "dayinvestor" piece.
Researchers report viability of telomerase in tissue engineering with no
evidence of cancer side effects
Updated: 09:46 et. Dec 29, 1999
Geron Corp's patented telomerase technology has been demonstrated in a tissue engineering study by
researchers at the Baylor College of Medicine and the University of Texas - Southwestern Medical Center. The
researchers reported in Nature Biotechnology that cells expressing telomerase and another viral protein survive
much longer when grown outside of the body and form functional tissue following transplantation in the body
without any evidence of cancer.
Dr. Jerry Shay of the University of Texas - Southwestern Medical Center told Dayinvestor.com "the importance of
this study is that it proves the viability of telomerase in tissue engineering". Dr Shay and his colleagues were
also involved in the Geron funded study causeing human cancer cell death by inhibiting telomerase see
previous story reported here on Dayinvestor.
Most cells die after a few divisions. But high levels of telomerase (TERT), an enzyme that restores the ends of
chromosomes, could extend cellular shelf life in the laboratory, enabling their culture for use in transplantation.
Immortality could be dangerous, however, as the presence of TERT has been suggested to increase the
likelihood that cells turn cancerous once transplanted into the body. Now, Peter Hornsby and colleagues have
shown that cells expressing TERT and another viral protein survive much longer when grown outside of the
body and significantly form functional tissue following transplantation in the body without any evidence for
cancer.
TERT repairs the tips of chromosomes, which would otherwise shorten every time a cell divides. Using the
premise that TERT could extend the life of cultured cells and enable their use in transplantation, Hornsby's team
expressed the enzyme in adrenal cells from cows, which they then transplanted into mice whose adrenal
glands had been surgically removed. When the mice were examined 36 days post surgery, the
TERT-expressing adrenal cells had formed functional adrenal tissue and appeared to be morphologically
normal, even though overexpression of TERT has been associated with the development and progression of
cancer, at least in certain cell types. The results were particularly surprising because the adrenal cells were
also given a gene encoding a known contributor to oncogenic progression, SV40 T antigen. They clearly show
that TERT overexpression is not an obligate step in cancer development, and that certain cells may be able to
tolerate its expression. Most importantly, the work opens up the possibility of growing almost unlimited supplies
of cells for therapeutic purposes.
FOCUS: Geron corp is engaged in the discovery and development of therapeutic and diagnostic products
used to treat cancer and age-related degenerative diseases. The company a biopharmaceutical company is
exclusively focused on discovering, developing and commercializing therapeutic and diagnostic products to
treat cancer and other age-related diseases.
¸Copyright 1999, Dayinvestor.com All rights reserved. |
