Objective To investigate the effects of small interfering RNA（siRNA） recombinant expression vector targeting survivin gene on chemotherapy sensitivity of human colon cancer cells to 5-fluorouracil.Methods siRNA recombinant expression vector targeting survivin gene was constructed and transfected into human colon cancer cell lines LOVO.After 48 hours of transfection

cells were harvested for analysis of survivin mRNA and protein expressions using RT-PCR and Western blot.In addition

after human colon cancer cell lines were treated with Survivin siRNA and/or 5-fluorouracil

MTT assay and flow cytometry were used to analyze cell proliferation and apoptosis.Results Restriction endonuclease analysis confirmed that siRNA recombinant expression vector targeting survivin gene was successfully constructed.Inhibitory ratios of survivin mRNA and protein expressions by Survivin siRNA were 36.33% and 44.65%

respectively.Survivin siRNA combined with 5-fluorouracil significantly increased the cell proliferation inhibitory ratio and apoptosis ratio compared with 5-fluorouracil treating alone（P<0.05）.Conclusion The siRNA recombinant expression vector targeting survivin gene can inhibit the expression of survivin gene

and enhance chemotherapy sensitivity of human colon cancer cells to 5-fluorouracil.