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 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.
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.