Differential telomerase activity, expression of the telomerase catalytic sub‐unit and telomerase‐RNA in ovarian tumors

• Published in: International journal of cancer Vol. 84; no. 4; pp. 426 - 431
• Main Authors: Park, Tjoung‐Won, Riethdorf, Sabine, Riethdorf, Lutz, Löning, Thomas, Jänicke, Fritz
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 20.08.1999; Wiley-Liss
• Subjects: Biological and medical sciences; Cystadenoma - enzymology; Cystadenoma - genetics; Female; Female genital diseases; Fibroma - enzymology; Fibroma - genetics; Gene Expression Regulation, Neoplastic; Gynecology. Andrology. Obstetrics; Humans; In Situ Hybridization - methods; Medical sciences; Ovarian Neoplasms - enzymology; Ovarian Neoplasms - genetics; Predictive Value of Tests; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - genetics; Telomerase - chemistry; Telomerase - genetics; Telomerase - metabolism; Telomere - genetics; Transcription, Genetic; Tumors; Human; Carcinoma; RNA-directed DNA polymerase; Enzyme; Transferases; Malignant tumor; Fibroma; Subunit; Carcinogenesis; Female genital diseases; Ovarian diseases; Ovary; Nucleotidyltransferases; Enzymatic activity; Low malignancy; Tumor progression; Benign neoplasm; Cystadenoma
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/(SICI)1097-0215(19990820)84:4<426::AID-IJC17>3.0.CO;2-1

Telomerase activity has been found in a variety of malignant tumors but only rarely in benign tumors or normal tissues. In this study, we investigated telomerase activation in 37 ovarian tumors, including benign, borderline and malignant neoplasms. Telomerase activity was detected using the telomeric repeat amplification protocol (TRAP) in 13/16 ovarian carcinomas, 9/10 borderline tumors and 3/11 cystadenomas/fibromas. mRNA expression of the putative human telomerase catalytic sub‐unit gene (hTERT) was detected by RT‐PCR in 14/15 ovarian carcinomas, 8/10 borderline tumors and 4/11 cystadenomas/fibromas. In situ hybridization was performed to evaluate telomerase‐RNA (hTR) expression in the corresponding paraffin‐embedded tumors. Variable expression levels of hTR were found over neoplastic tumor cells. The highest levels of hTR expression were found predominantly in ovarian carcinomas. Although the amount of telomerase activity varied, significantly high levels of telomerase activity were found predominantly in ovarian carcinomas. hTERT mRNA expression was closely associated with telomerase activity. These findings suggest that up‐regulation of hTERT and hTR is important for telomerase activation during malignant‐tumor progression. Telomerase activation might therefore be a valuable diagnostic parameter that could help to identify potentially progressive lesions. However, the diagnostic and therapeutic implications of telomerase activation need to be clarified in clinical trials. Int. J. Cancer (Pred. Oncol.) 84:426–431, 1999. © 1999 Wiley‐Liss, Inc.