Bcl-XL SiRNA Sensitizes Human MGC-803 Gastric Cancer Cells To 5-fluorouracil And Diallyl Disulfide

Objective To determine the inhibitory effect of the hairpin Bcl-XL siRNA on the expression of Bcl-XL gene in human gastric cancer cell line MGC-803, and to investigate the effect of Bcl-XL siRNA on drug sensitization in MGC-803 cells.Methods GFP siRNA was constructed and transiently transfected into MGC-803 cells, together with GFP expression vector PTrace SV-40. GFP expression level was observed by fluorescence microscopy. Then Bcl-XL siRNA and negative siRNA were constructed and stably transfected into MGC-803 cells. RT-PCR and immunofluorescence were used to detect the Bcl-XL gene expression. Spontaneous apoptosis of cells was detected by acridine orange (AO) and flow cytometry (FCM). Drug sensitivity of the cells to 5-fluorouracil (5-FU) and diallyl disulfide (DADS) was analyzed with MTT and flow cytometry.Results Extracted plasmids were confirmed by agarose gel electrophoresis,sequencing verified the correction of the GFP or Bcl-XL siRNA inserted templates. 48h After GFP and GFP siRNA co-transfection, the expression level of GFP gene in GFP siRNA group was much lower than negative siRNA group, according to fluorescence microscopy results. The mRNA and protein expression level of Bcl-XL in Bcl-XL siRNA stable transfectants was reduceDd 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, 13000mg/L of 5-FU (21.78 ± 1.58%vs 4.01 ± 2.26% or 6.85 ± 0.98%, 36.26± 1.15%vs 19.99 ± 1.00% or 20.47 ± 0.52%,42.21...