Inhibition of MCF-7 breast cancer cell by applying RNAi to silence STAT3 gene

Objective To investigate the inhibition of human breast cancer MCF-7 cell by applying RNAi technique to silence signal transducers and activators of transcription 3(STAT3) gene.Methods MCF-7 cells were transfected with recombinant plasmid psilencer1.0-U6STAT3-siRNA by using RNAi technique.The changes of proliferation,cell cycle,and apoptosis was examined by flow cytometry and MTT.The mRNA and protein expressions of STAT3 in cells were determined by Western blotting and RT-PCR,respectively.Results The growth and proliferation of MCF-7 cell was obviously inhibited and the apoptosis of MCF-7 cell was appeared.The mRNA and protein expressions of STAT3 in transfected cells were significantly lower than those of untransfected cells(P 0.01),but there were no significant difference between blank control group and empty plasmid control group(P 0.05).Conclusion Silencing STAT3 gene by the RNAi technology can decrease the expression of STAT3 gene,suppress the growth and proliferation of MCF-7 cell,and induce apoptosis of MCF-7 cell.