Effects of STAT3 Gene Silencing by ShRNA on Human Colorectal Cancer Cells

Objective To construct eukaryotic expression vectors of RNA interference of STAT3 gene and to investigate the effects of STAT3 expressing interference on proliferation of human colorectal cancer HT-29 cells.Methods Three sequences of siRNA targeting STAT3 gene were found from GenBank.The complementary DNA containing both sene and antisene Oligo DNA of the targeting sequence was designed,synthesized and cloned into the pRNAT-U6.1/Neo vector.The recombinant plasmids were conformed by PCR and the DNA sequence ana-lysis.HT-29 cells were transfected with the recombinant plasmids,and Real time quantitative PCR、Western-blot were used to certify the expression of STAT3 gene.In the transfected group with the best recombinant plasmid,the cell growth was assessed by MTT assay and the cell cycle distribution was detected by flow cytometry.Results PCR and the DNA sequence analysis demonstrated that the eukaryotic expression vectors of RNA interference of STAT3 gene were constructed successfully.STAT3 shRNA could inhibit the expression of STAT3 gene in HT-29 cells.In the transfected group with the best recombinant plasmid,MTT assay showed that the proliferation of HT-29 cells was suppressed and FCM assay indicated the proportion of cells at G0/G1 and S phase was (74.80±1.85)% and (15.72±2.26)% respectively,which was great different from that in the control group(P0.01).Conclusion STAT3 targeting shRNA can silence the STAT3 gene remarkably and induce HT-29 cell growth inhibition.