Effects of hTERT siRNA on expression of hTERT and repression of cell growth in breast cancer cells / 中国癌症杂志

ABSTRACT

Background and purpose:Overexpression of human telomerase reverse transcriptase(hTERT)plays a critical role in the process of immortalization of tumor cells.This study aims to investigate siRNA's effects on endogenous hTERT mRNA level and growth of breast cancer cells by targeting hTERT with its specific siRNA.The ultimate goal was to further elaborate the possible mechanism of immortalization in breast cancer cells.Methods:Real-Time RT-PCR was used to determine the hTERT transcripts in various breast cancer cells.hTERT siRNA was transfected into MCF7 cells with lipofectamine 2000.Cell growth was illustrated by growth curve,and cells apoptosis percentage was measured with Flow Cytometry(FACS).The relative expression levels of immortalization-related genes were evaluated with Real-Time RT-PCR.Results:Overexpressions of hTERT were demonstrated in all tested breast cancer cell lines.The inhibitory effects of hTERT siRNA were shown on both hTERT mRNA levels and cell growth from day 4 post transfection.Apoptosis was induced by hTERT siRNA as well.Certain immortalization-related genes were reduced by more than 50%,such as RAC1,PCYT2,FDFT1 and ATP5G2.Conclusions:hTERT siRNA specifically inhibited hTERT at mRNA level as well as cell growth.The apoptosis and downregulation of immortalization-related genes due to hTERT siRNA was demonstrated.