Bcl-XL siRNA sensitizes human MGC-803 gastric cancer cells to 5-fluorouracil and diallyl disulfide

AIM: To determine the inhibitory effect of the hairpin BclXL siRNA on the expression of Bcl-XL gene in human gastric cancer cell line MGC803,and the effect of Bcl-XL siRNA on drug sensitization in MGC-803 cells.METHODS: Bcl-XL siRNA and negative siRNA were constructed and stably transfected into MGC-803 cells.Immunofluorescence was used to detect the Bcl-XL gene expression.Drug sensitivity of the cells to 5-fluorouracil(5-FU) and diallyl disulfide(DADS) was analyzed with MTT and flow cytometry.RESULTS: Protein expression level of Bcl-XL in Bcl-XL siRNA stable transfectants was reduced to almost background level compared with negative siRNA transfectants or untreated cells.MTT results showed that the cells inhibitary rates of Bcl-XL siRNA transfectants were higher than that of negative vector or untreated cells after treated with 13,130,1300,and(13 000)(mg·L~(-1)) of 5-FU or treated with 20,35,and 50(mg·L~(-1)) of DADS.IC_(50) value of DADS or 5-FU in Bcl-XL siRNA transfected cells was significant lower than that of negative siRNA or untreated cells.Moreover,flow cytometry results demonstrated that Bcl-XL siRNA cells showed higher sub G_1 population than negative siRNA or untreated cells after addition 50(mg·L~(-1)) of DADS or 130(mg·L~(-1)) of 5-FU.CONCLUSION: siRNA targeting BclXL gene can specifically down-regulate Bcl-XL expression in MGC-803 cells,and sensitize cells to 5-FU or DADS.Bcl-XL siRNA may be a potential therapy agent against human gastric adenocarcinoma.