XIAP在TRAIL抗性细胞HCT116 bax-/-中的作用机制研究

为了探索结直肠癌细胞HCT116抗TRAIL诱导凋亡的分子机制,本课题以其抗性细胞HCT116 bax~(-/-)为实验对象进行了研究.通过利用目前最热的基因定点编辑技术Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated(Cas)9系统将HCT116bax~(-/-)的XIAP(X-linked inhibitor of apoptosis protein)基因彻底敲除后,用TRAIL处理,发现其恢复了对TRAIL的敏感,形态学发生了明显凋亡,而且western blot检测显示PARP蛋白发生了完全剪切.由此证明敲除XIAP基因能克服HCT116 bax~(-/-)对TRAIL的抗性.这些发现对肿瘤细胞抗TRAIL的分子机理研究以及肿瘤的个性化治疗有非常重要的意义.

The Machnism of XIAP and TRAIL Resistance in HCT116 bax-/-

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is one of the members of the tumor necrosis factor (TNF) superfamily. It can activate the apoptosis signaling pathways through engagement of the specific death receptors (DR4) or (DR5) in a broad range of cancer cell lines but not in normal cells. Thus, TRAIL is a potential anti-cancer agent. However, a small number of cancer cells may escape TRAIL induced cell death, and become resistant to it. For instance, targeted deletion of bax gene in human colorectal cancer cell line HCT116 (HCT116 bax-/-) renders the cells resistant to TRIAL induced apoptosis. In this project, we used gene-targeting technology CRISPR/Cas9 system to knock out the XIAP gene in HCT116 bax-/- cells. We showed that, as predicted, the loss of XIAP led to HCT116 bax-/- cells to overcome TRAIL resistance caused by bax deletion. This finding is significant for future study of the molecular mechanism behind cancer cell resistance to TRAIL and may help future personalized anti-cancer treatment.