Geron Presents New Data on Telomerase at AACR Meeting; Reports Significant Results on Cell Life-Span Extension
March 30, 1998 07:36 AM
MENLO PARK, Calif.--(BW HealthWire)--March 30, 1998--Geron Corporation announced new research results demonstrating that normal cells treated with the enzyme telomerase continue to divide and do not progress to cancer.
The research was presented at the 89th Annual Meeting of the American Association for Cancer Research (AACR) in New Orleans and the subject of an AACR media announcement yesterday.
Telomerase is an "immortalizing" enzyme that imparts replicative immortality when expressed in reproductive and cancer cells. Conversely, cells that do not express the enzyme are mortal. Research by Geron and others has shown that the aging of mortal cells is controlled by telomeres -- a chain of repeated DNA at the ends of chromosomes that shorten each time a cell divides.
At a certain telomere length, normal mortal cells stop dividing, a condition known as senescence. The expression of telomerase results in synthesis of telomeres which conveys unlimited replicative capacity. Telomeres can therefore be envisioned as "molecular clocks" that limit the life-span of cells, and telomerase can be envisioned as the "key" that rewinds the telomere clock.
At the AACR meeting, Calvin Harley, Ph.D., chief scientific officer at Geron, and Jerry Shay, Ph.D., professor of cell biology and neuroscience at the University of Texas Southwestern Medical Center at Dallas, provided new evidence that illustrates the impact on cell life-span by telomerase, first reported in the January 16, 1998 issue of Science.
The new data demonstrate that normal human cells treated with telomerase continue to divide and maintain normal structure and function, including a normal chromosome count, and show no signs of transformation. These results address the question raised by some oncologists, whether the use of telomerase to extend cell life-span would cause cells to behave like cancer cells.
The data also counter the concern of some gerontologists who questioned whether the life-span extension reported in January was significant. Drs. Harley and Shay reported to the AACR that telomerase-positive skin and retinal cells have doubled their life-span. In addition, these telomerase-positive cells have shown no signs of telomere loss, nor do they resemble old cells in their pattern of gene expression.
"These data demonstrate the fundamental distinction between telomerase as an immortality factor -- which is important in normal reproductive development and in cancer progression -- and oncogenes, which disrupt normal growth control and cause cells to transform and behave abnormally," stated Dr. Harley. "Therefore, the controlled extension of normal cell life-span by telomerase provides novel and promising opportunities in the treatment of
age-related diseases."
Geron Corporation is a biopharmaceutical company focused on discovering and developing therapeutic and diagnostic products based upon the company's understanding of telomeres and telomerase in cells -- fundamental biological mechanisms underlying cancer and other age-related diseases.
To receive an index and copies of recent releases, call Geron's News-On-Demand toll free fax service, 1-800/782-3279. Additional information about the company can be obtained at geron.com.
The company desires to take advantage of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. Specifically, the company wishes to alert readers the matters discussed in this press release may constitute certain forward-looking statements. Additional information on potential factors that could affect the company's financial results are included in the company's annual report on Form 10-Q for the quarter ended Sept. 30,
1997.
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