【摘要】 目的探讨应用RNA干扰靶向抑制PI3Kp85α表达对5-FU诱导大肠癌LoVo细胞凋亡的影响。方法培养已成功沉默PI3Kp85α表达的大肠癌LoVo细胞(PI3Kp85α/RNAi-LoVo)及LoVo对照组细胞,MTT法计算两组细胞5-FU的半数抑制率(IC50),JC-1染色检测线粒体膜电位(Δψm)的变化,Western blotting检测凋亡蛋白Bcl-6和Bim的表达。结果 PI3Kp85α/RNAi-LoVo细胞组5-FU的IC50值(1.056±0.03562μmol/L)显著低于LoVo对照组(2.796±0.10947μmol/L)(P=0.000),JC-1染色显示5-FU刺激48h后,PI3Kp85α/RNAi-LoVo细胞线粒体膜电位较LoVo对照组细胞显著降低,表明PI3Kp85α/RNAi-LoVo细胞对5-FU更敏感。5-FU刺激48h后,PI3Kp85α/RNAi-LoVo细胞组凋亡蛋白Bcl-6和Bim的表达较LoVo对照组细胞显著增加(P=0.000)。结论应用RNA干扰靶向抑制PI3Kp85α表达可促进5-FU诱导大肠癌细胞LoVo的凋亡。更多还原

【Abstract】 Objective To explore the effect of PI3K p85α gene silencing on the 5-fluorouracil (5-FU)-induced apoptosis of colorectal cancer cells. Methods The PI3K p85α/RNAi transfected cells (PI3K p85α/RNAi-LoVo) were cultured in RPMI 1640 supplemented with 10% fetal calf serum and 500 μg/ml G418. The 50% inhibitory concentration (IC50) values of 5-FU (0.000625, 0.00125, 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32 μmol/ml) were evaluated by MTT assay. Mitochondrial membrane potential was detected by JC-1 fluorescence, and Western blotting was used to analyze the expression of apoptotic proteins Bcl-6 and Bim. Results Compared with the untransfected LoVo cells, PI3K p85α/RNAi-LoVo showed obviously decreased IC50 of 5-FU (P=0.000). The mitochondrial membrane potential of PI3K p85α/RNAi-LoVo cells was significantly lower than that of LoVo cells, suggesting that silencing PI3K p85α expression increased the sensitivity of LoVo cells to 5-FU. The expression of apoptotic protein Bcl-6 and Bim were significantly higher in PI3K p85α/RNAi-LoVo cells treated with 5-FU than LoVo cells (P=0.000). Conclusion PI3Kp85α gene silencing can significantly promote 5-FU-induced apoptosis of colorectal LoVo cells.更多还原