Construction of STAT3-siRNA expression vector and its effect on proliferation of stomach cancer cell line HGC-27

Objective To construct siRNA expression vectors targeting the signal transducer and activator of transcription the 3(STAT3) gene and to examine the inhibitory effect of siRNAs on expression of STAT3 and its effect on proliferation of stomach cancer cell line HGC-27.Methods Two STAT3-siRNA fragments were synthesized,and then transfected into HGC-27 cells.STAT3 mRNA and protein were examined by RT-PCR and Western blot,respectively.Inhibition of proliferation was determined by the MTT assay.Results Two STAT3-siRNA expression vectors were found to contain the correct siRNA sequences,as confirmed by sequencing and enzymatic digestion.Results of RT-PCR and Western blot showed that the abundances of STAT3 mRNA and protein were significantly decreased relative to both the control and si-NC groups(P0.01),resulting in STAT3-siRNA1 being more pronounced than with STAT3-siRNA2.MTT assay showed that,after transfection,cell proliferation in the siRNA group was significantly reduced compared with the si-NC group(P0.01).Conclusion Expression of STAT3-siRNA in stomach cell line HGC-27 can effectively inhibit STAT3 expression,leading to proliferation suppression.