Telomerase Activity Is Associated with Cell Cycle Deregulation in Human Breast Cancer

摘要: Deregulation of the cell cycle by abnormal expression one or several regulatory proteins is a common finding in malignant tumors and might be prerequisite for cancer development. Telomerase activity an immortalization marker that found most cancers which association with active has been implicated. In tissue 106 human breast carcinomas, we analyzed relationship between telomerase levels defects machinery focus on retinoblastoma protein (pRB) pathway(s). The fraction telomerase-positive was 85%, large differences were found. Overexpression cyclin D1 and/or E, combination normal pRB, typical feature high levels. Down-regulation p16INK4 not related per se to activity, but low E overexpression demonstrated activity. Tumor proliferation, determined Ki-67 expression, correlated significantly There was, however, strict proliferation rate because inactivated pRB had highest fractions intermediate Also, associated without increase tumor proliferation. present study indicates activation occurs preferentially certain may depend specific defect(s).