Objective　　　To prepare a recombinant adenovirus vector containing human signal transducer and activator of transcription 3 (STAT3)

and to investigate the STAT3 expression in gastric cancer cell line SGC-7901 and its effect on proliferation in the cells.　　　 Methods　　　The complete coding sequence of human STAT3 was obtained by PCR using the cDNAs of placenta from healthy volunteers as a template. The hSTAT3 was cloned into a T vector pTA2 and sequenced

and th

en the STAT3 was subcloned into a shuttle plasmid pAdTrack-CMV. The linearized product of pAd-Track-CMV-STAT was transferred into BJ5183 Escherichia coli for homologous recombination with pAdeasy-1 vector. The recombined adenovirus DNA was transfected into 293FT cells for packaging and amplifying after linearized by PacⅠ

and then the titer of successfully packaged recombinant adenovirus was determined. The recombinant adenovirus vector containing human STAT3 (AdV-STAT3) was taken to transfect SGC-7901 cells

and the recombinant adenovirus vector containing GFP (AdV-GFP) was used as control. The expression of STAT3 was detected by Western blotting and the effect of STAT3 on cell proliferation was determined by MTT assay.　　　 Results　　　The complete coding sequence of human STAT3 gene was obtained

and was confirmed by sequencing analysis after cloned into the T vector pTA2. The STAT3 gene was successfully constructed into the recombinant adenovirus plasmid after being subcloned into the shuttle plasmid pAdTrack-CMV. The titers of pAdEasy-1-STAT3 and pAdEasy-1-GFP were 2.8×10

10

pfu/mL and 3.2×10

10

pfu/mL. Comparing with AdV-GFP and blank control

Western blot assay showed that the proteins expression of STAT3 significantly was increased in the AdV-STAT3 group (P0.05). MTT assay showed that the proliferation of the SGC-7901 cells was significantly increased after transfected with AdV-STAT3 (P0.05).　　　 Conclusion　　　Adenovirus vector AdV-STAT3 is successfully obtained. STAT3 protein can be highly expressed in SGC-7901 cells and promote cell proliferation.