Effect of RNA interference targeting STAT3 on the proliferation and invasion of gastric cancer cell

OBJECTIVE:To construct a expression vector of short hairpin RNA targeting STAT3 gene and observe its effects on cell growth and invasion ability of human gastric cancer cell line BGC-823 in vitro.METHODS:The recombinant plasmid pSilencer-STAT3 was constructed by combination of double-strand DNA containing STAT3 with vector pSilencer that underwent restriction digest.Then these recombinant plasmids were transfected by liposome into BGC-823 cells.The expression of STAT3 mRNA and protein were detected by RT-PCR and Western-blot.MTT assay was applied to assess cell proliferation.The invasion ability of BGC-823 cells was determined by transwells assay.RESULTS: Restriction enzyme digesting assay and DNA sequencing analysis was confirmed successful construction of recombinant plasmid pSilencer-STAT3.Compared with the non-transfected group and pSilencer-neospecial group,pSilencer-STAT3 inhibited the expression of STAT3 mRNA in BGC-823 cells(F=39.424,P=0.000).The expression of STAT3 protein was also knocked down by pSilencer-STAT3 siRNA(F=31.911,P=0.001).The proliferation of the BGC-823 cells was suppressed significantly(47.3%) after transfection of pSilencer-STAT3 recombinant plasmid,which was markedly higher than that of the pSilencer-neospecial vector control group(8.1%,F=40.835,P=0.000).The migration of the recombinant plasmid-transfected cells was significantly suppressed compared with that of cells transfected with pSilencer-neospecial vector or non-transfected(75±10,111±10,104±9,F=11.311,P=0.009).CONCLUSION:Recombinant plasmid pSilencer-STAT3 can significantly reduce STAT3 gene expression in human gastric cancer cell BGC-823 and inhibit the proliferation and invasion ability.