Telomerase Activity in Gynecologic Cancers and correlation of HPV E6 gene expression in cervical cancer tissues

You, Yong Sin; Lee, Seon Kyung; Kim, Seung Bo; Chi, Sung Gil

Abstract

OBJECT: In this study, to evaluate the putative role of telomerase in gynecologic malignancies (cervical ca, ovarian ca, endometrial ca), we measured telomerase activity in malignant gynecologic tumor tissues and normal tussues, and compared it with prognostic factors in cervical cancer. To evaluate the correlation of telomerase activity and human papillomavirus (HPV) infection in cervical cancer, the analysis of HPV E6 gene was performed. METHOD: Specimens were obtained from 51 women who underwent gynecologic radical operation and 13 normal tissues (from December 1995 to December 1996) in the Department of Obstetrics and Gynecology, Kyung-Hee Univ. Medical Center. With Telomerase PCR ELISA (Boehring Mannheim), modified TRAP (Telomere Repeat Amplication Protocol), we examined telomerase activity of 32 cervical carcinomas, 11 ovarian carcinomas, 8 endometrial carcinomas, 5 normal cervical tissues, 4 normal ovarian tissues and 4 normal endometrial tissues. The analysis of HPV E6 gene was performed by PCR amplication. We compared the abnormally high telomerase activity with prognostic factors, also compared the telomerase activity with the expression of HPV E6 gene in cervical cancer tissues. RESULT: We detected the abnormally high telomerase activity in all cervical carcinomas, 10 of 11 (90.9%) ovarian carcinomas, 6 of 8 (75.0%) endometrial carcinomas, but couldn't detect in each normal tissues. There was statistically no significant difference of telomerase activity levels according to age, clinical stage, pathology, differentiation, LN involvement, depth of invasion and tumor size except lymphovascular space invasion in cervical carcinomas (p<0.05). According to the analysis of HPV E6 gene, 29 of 32 (90.6%) in 32 cervical cancer tissues showed HPV E6 positivity. So it was considered that telomerase activation was closely related with the expression of HPV E6 gene.
CONCLUSION
Telomerase activation is associated with immortalization or malignant transformation of gynecologic cancers. The expression of HPV E6 gene is considered to activate telomerase in cervical cancer.