Quantitative analysis of telomerase hTERT mRNA and telomerase activity in endometrioid adenocarcinoma and in normal endometrium

Abstract

Objectives: In the current study, the quantitative levels of telomerase hTERT mRNA and the functional telomerase repeat amplification protocol (TRAP) assay were correlated with tumor grade in endometrial carcinomas and with the histologic phase of normal endometrium.

Methods: Twenty-six samples of endometroid adenocarcinoma and 20 cases of benign endometrium were obtained from hysterectomy specimens. Total RNA was extracted from each tissue sample and used for quantitative real-time RT-PCR of hTERT mRNA and the levels were standardized to the levels of ribosomal RNA. Quantitative determination of telomerase activity was performed by the polymerase chain-based TRAP assay and the levels of expression were defined by the ratio of radioactivity incorporated into the 6-bp telomerase amplification products versus the radioactivity incorporated into an internal standard (telomerase/ITAS x 100 = 1 RU). Statistical analyses were performed using the Fisher exact test or chi2 test, a Wilcoxon rank sum test, and a linear regression analysis.

Results: hTERT mRNA and telomerase activity levels showed a linear association in the study group (P = 0.006, R2 = 0.139). hTERT mRNA levels and telomerase activity levels were significantly higher in endometrial cancer (179 pg/ng rRNA, 44 relative units (RU)) than in normal endometrium (45 pg/ng), (15 RU) (P = 0.009, P = 0.006). In normal endometrium, hTERT mRNA and telomerase activity levels were highest in the proliferative phase (74 pg/ng rRNA, 25 RU) and were relatively low in secretory (13 pg/ng rRNA, 6 RU) and atrophic endometrium (9 pg/ng rRNA, 2 RU).

Conclusion: These results suggest that the quantitative analysis of hTERT and telomerase activity may have potential roles as diagnostic or prognostic adjuncts for both premenopausal and postmenopausal patients with endometrial cancer.