Abstract:

Objective     To investigate the effects of overexpression human signal transducer and activator of transcription 3(STAT3) on human gastric cancer cell line MGC803 by the construction of a STAT3 gene eukaryotic expression vector. Methods    The eukaryotic expression vector pcDNA3-STAT3 was constructed and transfected into the gastric cancer cell line（MGC803) by the liposome. The mRNA and protein expression levels of STAT3, P-STAT3(Y705), P-STAT3(S727), Survivin and PCNA in MGC803 were detected by RT-PCR and Western blotting. The effects of STAT3 on MGC803 cell proliferation were detected through the CCK-8 assay. Results   The DNA sequencing and restriction endonuclease identification results confirmed that the eukaryotic expression plasmid pcDNA3-STAT3 was successfully constructed. Western blotting and RT-PCR results confirmed that STAT3, P-STAT3(Y705), P-STAT3(S727), Survivin and PCNA protein and mRNA expression levels were significantly increased in the recombinant plasmid group compared with the empty vector group. CCK-8 results proved that, compared with the empty vector group，the recombinant plasmid group showed higher proliferative capacity, and the difference was statistically significant (P<0.05). Conclusion    eukaryotic expression plasmids of pcDNA3-STAT3 can increase the expression of STAT3 gene in human gastric cancer cell line MGC803, and enhance the proliferation of gastric cancer cells.

Key words: Stomach neoplasm; Signal transducer and activator of transcription 3; Cell proliferating ability