Construction and identification of RNA interference expression vector of targeting Stat3

Objective To construct RNA interference expression vector of targeting Stat3 and test the silencing effect by using liposome transfecting colon cancer cell line HCT116 to make foundation for exploring new way of gene therapy for cancer. Methods Two DNA sequences containing small hairpin structure were designed and synthesized. The complement form obtained by annealing was inserted into vector Pavu6+27 to construct the recombinant Pavu6+27-Stat3, the plasmid of which was then identified by enzyme digestion and DNA sequence analysis. The recombinant plasmid was transfected into human colon cancer cell line HCT116 by DOTAP method to assay the suppression effect of Stat3 by RT-PCR 48 hours after transfection. Empty plasmid (Pavu6+27) transfected into the same cell line was set as control group. Results The enzyme digestion analysis and DNA sequencing showed that RNA interference expression vector of targeting Stat3 was constructed successfully. The expression of Stat3-mRNA in HCT116 cell line transfected with Pavu6+27-Stat3 was weaker than that transfected with Pavu6+27. Conclusions RNA interference expression vector of targeting Stat3 is successfully constructed and can effectively inhibit expression of Stat3 in colon cancer cell line HCT116. Our study makes a foundation for gene therapy for cancer by using RNAi technique to silence expression of gene Stat3 in cancer cells and induce apoptosis or inhibit proliferation of cancer cells.