TELOMERASE ACTIVITY ASSOCIATED WITH ACQUISITION OF MALIGNANCY IN HUMAN COLORECTAL-CANCER

Shortening of telomeres may contribute to the control of the prolifera tive capacity of normal cells, and telomerase, the enzyme that elongat es telomeric DNA, may be essential for unlimited cell proliferation. W e have shown previously that telomerase activity is present in human c ells immortalized in vitro and in metastatic ovarian carcinoma cells b ut is undetectable in normal cultured cells or normal tissues. We have determined the temporal pattern of telomerase activity during colorec tal carcinogenesis in man. We report that telomerase activity is assoc iated with acquisition of malignancy as it is detectable in colorectal carcinoma but not in adenomatous polyps, Mutations leading to reactiv ation or upregulation of the enzyme may represent an additional requir ed event in the multistep development of colorectal cancer.