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Biotech / Medical : Geron Corp. -- Ignore unavailable to you. Want to Upgrade?

To: louis mason who wrote (969)	3/21/1998 9:46:00 PM
From: Mr.Rich Nouveau	Respond to of 3576

I'm relatively new here, and have not read all the 900+ posts on Geron. Furthermore, I'm not a patent attorney. I would agree with you, however, that in the pharmaceutical business, it is exceedingly difficult to "own" a target (i.e., telomerase). Correct me if I'm wrong, but it generally seems that patents on assay technology prevents other companies from "selling" the same assay technology (i.e., on a contract basis), but it not too effective in keeping other companies from using such assays, or more likely, slight variations thereof, in the own internal research programs. I personally do not know of any successful litigation where rights where claimed to a small molecule drug which was assayed using a patented assay. After all, the drug is what is being sold, not the assay. Thus, I don't think there is any big barrier to competition (in addition to BMS) entering the field. In the end, I think the race to find telomerase inhibitors will be won, if indeed it is do-able, by the best drug discovery team. According to this premise, I don't think Geron brings all that much to the table; it will depend more on Pharmacia-Upjohn. Just my 2›! R.N.

To: louis mason who wrote (969)	3/26/1998 11:55:00 AM
From: Rob-Chemist	Read Replies (1) \| Respond to of 3576

Enclosed is the abstract from an article that raises an interesting hypothesis: the presence of telomerase in cells is more related to whether or not the cells are growing, rather than the question of whether they are cancerous. Proc Natl Acad Sci U S A 1997 Dec 9;94(25):13677-13682 Telomerase activity: a biomarker of cell proliferation, not malignant transformation. Belair CD, Yeager TR, Lopez PM, Reznikoff CA Department of Human Oncology, University of Wisconsin Medical School, Madison, WI 53792, USA. Telomerase activity is readily detected in most cancer biopsies, but not in premalignant lesions or in normal tissue samples with a few exceptions that include germ cells and hemopoietic stem cells. Telomerase activity may, therefore, be a useful biomarker for diagnosis of malignancies and a target for inactivation in chemotherapy or gene therapy. These observations have led to the hypothesis that activation of telomerase may be an important step in tumorigenesis. To test this hypothesis, we studied telomerase activity in isogeneic samples of uncultured and cultured specimens of normal human uroepithelial cells (HUCs) and in uncultured and cultured biopsies of superficial and myoinvasive transitional cell carcinoma (TCC) of the bladder. Our results demonstrated that four of four TCC biopsies, representing both superficial and myoinvasive TCCs, were positive for telomerase activity, but all samples of uncultured HUC were telomerase negative. However, when the same normal HUC samples were established as proliferating cultures in vitro, telomerase activity was readily detected but usually at lower levels than in TCCs. Consistent with the above observation of the telomerase activity in HUCs, telomeres did not shorten during the HUC in vitro lifespan. Demonstration of telomerase in proliferating human epithelial cells in vitro was not restricted to HUCs, because it was also present in prostate and mammary cell cultures. Notably, telomerase activity was relatively low or undetectable in nonproliferating HUC cultures. These data do not support a model in which telomerase is inactive in normal cells and activated during tumorigenic transformation. Rather, these data support a model in which the detection of telomerase in TCC biopsies, but not uncultured HUC samples, reflects in proliferation between tumor and normal cells in vivo.