Effect of hTERT gene silencing by RNA interference on proliferation and apoptosis of human breast cancer cells

Objective To evaluate the effect of targeting hTERT gene on the proliferation and apoptosis of MCF-7cells. Methods Chemically synthesized small interfering RNA (siRNA) targeting hTERT was transfected into human breast cancer cell line MCF-7 by LipofectamineTM 2000. The expression levels of hTERT mRNA and protein were detected respectively by real time PCR and Western blot. Cell proliferation was determined by MTT,and the cell colony formation rate was measured by plate colony formation assay, and cell apoptosis was observed by flow cytometry. Results The expressions of hTERT in both mRNA and protein of MCF-7 cells were effectively decreased by the siRNA targeting human hTERT gene; the hTERT mRNA levels in the groups of siRNA1, siRNA2 and siRNA3 were respectively reduced to (35.3±4.2)%, (30.7±2.8)% and (31.3±3.6)% at 48 hours after transfection, and were significantly lower than that of the negative control group (96.4±2.8%). MTT results showed that the growth rate of MCF-7 cells was decreased markedly. In the groups of siRNA1, siRNA2, siRNA3 and siRNA4, the inhibition ratios after 48-hour-transfection were (57.6±3.6)%, (61.3±4.3)%, (65.6±6.3)% and (3.1±4.5)%, respectively. Moreover, the cell colony formation rates were statistically decreased in hTERT siRNA groups, and the apoptosis was increased significantly. Conclusion The synthesized siRNA can effectively decrease the hTERT gene expression, inhibit cell proliferation and induce cell apoptosis. hTERT siRNA can be used as a new approach in human breast cancer gene therapy.