[Construction of eukaryotic expression vector of siRNA specific for MAD2 and its effect on the growth of gastric cell line SGC7901].

Aim: To construct the RNA interference eukaryotic expression vector specific for human MAD2 gene and to observe its effect on the growth of gastric cancer cell line SGC7901.

Methods: The expression vectors of pSilencer3.1/MAD2-siRNA1 and pSilencer3.1/MAD2-siRNA2 were constructed by gene recombination and then were stably transfected into the gastric carcinoma cell line SGC7901 by liposome mediation. The expression of MAD2 on the levels of protein and mRNA was detected by Western blot and RT-PCR, and the monoclone with the highest inhibition efficiency was selected. The growth of the transfected cells was assessed by MTT. And the cells treated with 1.0 mg/L vincristine (VCR) for 24 h were analyzed by FCM for cell cycle.

Results: Sequence-specific siRNAs targeting MAD2 significantly down regulated the expression of MAD2 in SGC7901 cells. In MAD2-siRNA transfected cells, the rate of cell growth increased markedly and cell cycle couldn't be arrested in M phase induced by VCR, while the cells transfected with the mock vector could.

Conclusion: Down regulation of MAD2 expression of SGC7901 bv sequence-specific siRNA could accelerate the cell growth and impair the mitosis arrest of SGC7901 induced by VCR.