抑制c-FLIP基因促进TRAIL诱导的乳腺癌细胞凋亡

目的：探讨抑制c-FLIP的表达对TRAIL诱导乳腺癌细胞MCF-7凋亡的影响。方法：重组腺病毒Ad-c-FLIP-siRNA和Ad-sTRAIL单独及联合感染对TRAIL耐药的乳腺癌细胞MCF-7,应用实时荧光定量聚合酶链反应（Real-time PCR）检测病毒感染后各组细胞内c-FLIP和TRAIL的mRNA表达变化；MTT法和结晶紫染色法检测MCF-7细胞活性,Hoechst 33258荧光染色检测各组细胞的凋亡情况。结果：与阴性对照组比较,c-FLIP-siRNA组和c-FLIP-siRNA＋TRAIL组c-FLIP的mRNA相对表达量分别是（0.32±0.16）和（0.39±0.48）倍；TRAIL组和c-FLIP-siRNA＋TRAIL组TRAIL的mRNA相对表达量分别是（96.21±1.54）和（87.33±1.66）倍；TRAIL组、c-FLIP-siRNA组及c-FLIP-siRNA＋TRAIL组的抑制率（%）分别为（60.27±1.25）、（11.34±1.74）及（74.91±2.12）。对比阴性对照组的凋亡率（3.12±1.54）,TRAIL组（12.79±2.46）和c-FLIP-siRNA＋TRAIL组（25.50±3.17）组的凋亡率明显增高（P〈0.05）,c-FLIP-siRNA组（6.85±2.82）的凋亡率变化不明显,差异无统计学意义（P〉0.05）。结论：siRNA抑制c-FLIP基因的表达能显著促进TRAIL对乳腺癌细胞MCF-7凋亡的诱导作用。

Down-regulation of c-FLIP Gene by siRNA Interference Enhances Breast Cancer Cells to TRAIL-Induced Apoptosis

Objective： To investigate the effect of c-Flip gene suppression on enhancing breast cancer cell MCF-7 to TRAIL-induced apoptosis. Methods： MCF-7 cells were infected with recombinant adenoviruses Ad-cFLIP-siRNA and Ad-sTRAIL, alone or combined respectively. Real-time quantitative polymerase chain reation（Real time PCR） was used to detect the expression of c-FLIP and TRAIL in MCF-7 cells. Methythiazol tetrazolium（MTT） assay and Crystal violet staining were applied to detect the cell proliferation. And Hoechst 33258 staining was used to detect the apoptosis of MCF-7 cells. Results： Compared with that in the negative control group, the relative expressions of c-FLIP in the c-FLIP-siRNA and the c-FLIP-siRNA＋TRAIL groups were（0.32 ±0.16） and（0.39±0.48） times respectively; The relative expressions of TRAIL in the TRAIL and the c-FLIP-siRNA＋TRAIL groups were（96.21±1.54） and（87.33±1.66） times respectively. The inhibition rate（%） of cells in TRAIL, c-FLIP-siRNA, and TRAIL＋c-FLIP-siRNA group were（60.27±1.25）,（11.34±1.74） and（74.91±2.12）, respectively. Compared with that in the negative control group（3.12±1.54）, the apoptosis rates of cells in TRAIL（12.79±2.46） and c-FLIP-siRNA＋TRAIL group（25.50±3.17） increased significantly（P〈0.05）.However, the apoptosis rates of cells in c-FLIP-siRNA group（6.85±2.82） had no statistical significance with that in negative control group（P 〉0.05）. Conclusion： Down-regulation of c-FLIP by siRNA interference could enhance the breast cancer cells MCF-7 to TRAIL-induced apoptosis.