Objective     To design and construct a vector of signal transducer and activator of transcription 3 (STAT3) small interfering RNA (siRNA)，and to investigate the effect of the recombinant plasmid on the proliferation and apoptosis of gastric cancer cell SGC7901.      Methods     The PAVU6＋27-STAT3 siRNA expression vector was constructed， then transfected into the cultured gastric cancer cells SGC7901 by DOTAP method. STAT3 mRNA and protein in SGC7901 were determined by RT-PCR and Western blotting respectively. Cell proliferation was tested by MTT and

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H-TdR incorporation. Cell apoptosis percentage and bcl-2 expression were observed by TUNEL and flow cytometry respectively.      Results     The PAVU6＋27-STAT3 siRNA expression vector was successfully constructed. In the transfected SGC7901 cells

cell proliferation

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H-TdR incorporation and bcl-2 expression were decreased

and cell apoptosis percentage was increased.      Conclusion     PAVU6＋27-STAT3 siRNA expression vector may be an efficient method to inhibit the proliferation and promote the apoptosis of gastric cancer cells.