Telomerase activity in malignant ovarian tumors with deregulation of cell cycle regulatory proteins

Using a semiquantitative telomeric repeat amplification protocol assay, tel omerase-positive frequencies and enzyme levels were measured. Out of 95% of 49 human ovarian tumors, the highest level of telomerase activity was obse rved in malignant tumors. Furthermore, by immunohistochemical staining of c ell cycle regulatory proteins (pRB, p16, cyclin D1, cyclin E and p53) at th e G1 checkpoint, we evaluated the relation between each protein alterations and the levels of telomerase activity. We could not demonstrate a clear re lation with each molecule except for cyclin E, but suggesting that aberrant accumulation of these proteins was considered as a reason for telomerase d eregulation, which may play an essential role in the pathway of telomerase regulation. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.