靶向抑制XIAP基因后结肠癌细胞对凋亡诱导配体耐药性的变化

目的 观察应用短发夹RNA(shRNA)干扰质粒靶向抑制X连锁凋亡抑制蛋白(XIAP)基因后,结肠癌细胞SW1116对肿瘤坏死因子相关的凋亡诱导配体(TRAIL)耐药性的变化.方法 采用脂质体包裹方法,将干扰质粒转染结肠癌细胞SW1116,48 h后检测转染前后XIAP蛋白表达和结肠癌细胞生长活性的变化;应用TRAIL药物25、50、100、200 μg/L梯度浓度作用于结肠癌细胞,24 h后噻唑蓝(MTT)比色法检测抑制XIAP表达后结肠癌细胞对TRAIL敏感性的变化,并利用蛋白印迹方法检测细胞内凋亡相关因子Caspase-3活性的改变.结果 转染干扰质粒后XIAP的表达能够得到有效抑制(抑制率60%),细胞的生长活性得到抑制(抑制率24%),结肠癌细胞对TRAIL的耐药得到逆转,对TRAIL的敏感性显著提高,在200μg/L浓度下细胞生长抑制率可达64%,肿瘤细胞内的Caspase-3的表达活性得到提高.结论 靶向抑制XIAP基因的表达能够恢复和增强结肠癌细胞对TRAIL的敏感性.

Targeted inhibition of XIAP expression reverses resistance of colon cancer cells to TNF-related apoptosis-inducing ligand

Objective To study the resistance changes of colon cancer cells SW1116 to TNF-related apoptosis-inducing ligand ( TRAIL) after targeted inhibition of X-linked inhibitor of apoplosis protein (XIAP) expression by small hoop RNA plasmid. Methods Colon cancer cells were transfected by XIAP short hairpin RNA (shRNA) plasmid with liposorae. Inhibition rate and cell viability were examined 48 h post-transfection. SW1116 cells were exposed to TRAIL at concentrations of 25, 50, 100, 200 μLg/L, and their sensitivity to TRAIL was evaluated after inhibition of the XIAP expression. Caspase-3 activity in tumor cells was also evaluated by Western blotting. Results XIAP expression was decreased significantly after XIAP shRNA transfection (inhibition rate 60% ) , cell growing rate was inhibited (inhibition rate 24% ) , resistance to TRAIL was reversed, sensitivity to TRAIL was increased, cell growing inhibition rate reached 64% in 200 μg/L of TRAIL, and Caspase-3 activity was increased in tumor cells. Conclusion Targeted inhibition of XIAP expression restored and increased sensitivity of colon cancer cells to TRAIL.