Down-regulation Human TERT Gene Of Telomerase In A2780 Cells Of Ovarian Cancer By RNA Interfering Technology

Telomerase is a ribonucleoprotein complex that extends telomerases of eukaryotic chromosomes,cell replicative potential and lifespan. Now,maintains and regulates telomerase has become cancer an attractive molecular target toward which to direct therapeutic agents because telomerase activation is observed in almost 90% malignant cells but not in most normal somatic cells. Human telomerase is composed of an RNA subunit(hTR) that contains the template for telomeric DNA and several protein components that include the catalyst telomerase reverse transcriptase(hTERT) and telomerase-associated protein 1 (hTEPl) .hTR and hTEPl are widely expressed in normal human tissues,whereas hTERT is expressed concomitantly with the activation of telomerase during cellular immortalization and plays a pivotal role in carcinogenesis.Recently, more and more researches indicated human telomerase catalytic subunit mRNA may be the critical rate-limiting step in the activation of telolmerase.RNA interference(RNAi) has been shown to interfere the expression of correlating mRNA in various species.This study proposed to inhibit the expression of human telomerase reverse transcriptase (TERT) and the growth of cells in ovariancancer cells. The TERT expression was detected by RT-PCR methods among ovarian cancerA2780cells, SKOV3 cells and HO-8910 cells. The TERT expression in A2780 cells was higher than the others. hTERT cDNA sequences from nucleotides1523-1543,2773-2791 and there's corresponding antisense nucleotides followed by five thymines were linked by 9bp nucleotides and cloned to the downstream of CMV promoter in pSilencer4.1CMV-puro vector, resulting in the RNA interference vector pSilencer-CMV-hTERT1 and...