索拉非尼激活NLRP3炎性体诱导肝癌细胞焦亡的机制研究

The NLRP3 inflammasome plays a very important role in the effecacy of antitumor drugs and the regulation of hepatoma cell death. Sorafenib is the first-line treatment for advanced hepatocellular carcinoma (HCC), but the relationship between NLRP3 inflammasome and the anti-tumor function of sorafenib remains unknown so far. In the previous study, we found that IL-1βand IL-18 levels in plasma from patients with advanced HCC were significantly increased after sorafenib treatment compared with the baseline levels, and the rate of increase was positively correlated with drug response. The sorafenib could stimulate the expression of IL-1β, IL-18 and NLRP3 in hepatoma cells in vitro. The blocking antibody and chemical inhibitor which might block the formation and activation of NLRP3 inflammasome could prevent the death of hepatoma cell induced by sorafenib. Based on these new findings, we put forward the hypothesis that sorafenib can induce hepatoma cell death by regulating the activation of NLRP3 inflammasome. In this study, clinical samples will be used to explore the activation of NLRP3 inflammasome induced by sorafenib , and its role in antitumor response. Then, HCC cell models and animal models are used to clarify the effects of sorafenib on NLRP3 inflammasome activation and the molecular mechanism, and expound their function in HCC cell death and anti-tumor effect in vivo. This study will increase our understanding on the antitumor mechanism of sorafenib, and supply new targets of HCC treatment.

NLRP3炎性体在影响抗肿瘤药物疗效及促进肝癌细胞死亡中具有重要的意义。但是索拉非尼作为晚期肝癌的一线标准治疗药物，NLRP3炎性体与其抗肿瘤作用的关系未见报道。申请者发现索拉非尼治疗的晚期肝癌患者血清中IL-1β和IL-18水平显著升高，并与药物应答效果呈正相关。索拉非尼可以在体外促进肝癌细胞中IL-1β、IL-18及NLRP3的表达。封闭抗体及化学抑制剂阻断NLRP3炎性体形成及活化阻遏索拉非尼诱导肝癌细胞死亡。由此提出假说：索拉非尼可以调控NLRP3炎性体形成及活化诱导肝癌细胞死亡。为论证该假说，本项目通过肝癌病例探讨索拉非尼活化NLRP3炎性体与临床治疗的关系。利用细胞及动物模型深入研究索拉非尼对NLRP3炎性体的激活作用及分子机制，明确索拉非尼激活NLRP3炎性体在调控肝癌细胞死亡及抗肿瘤治疗中的意义。该研究将为索拉非尼抗肝癌的分子机制提供新认识，并为肝癌的治疗及预后提供新靶点。

肝细胞癌是临床上最常见的恶性肿瘤之一，居恶性肿瘤第二位，中国的发病率及死亡率均占据全球 50%以上，居世界首位。前期课题组研究提示NLRP3炎性体在影响抗肿瘤药物疗效及促进肝癌细胞死亡中具有重要的意义。但是索拉非尼作为晚期肝癌的一线标准治疗药物，NLRP3炎性体与其抗肿瘤作用的关系未见报道。本课题研究发现索拉非尼治疗的晚期肝癌患者血清中IL-1β和IL-18水平显著升高，并与药物应答效果呈正相关。索拉非尼可以在体外促进肝癌细胞中IL-1β、IL-18及NLRP3的表达。封闭抗体及化学抑制剂阻断NLRP3炎性体形成及活化阻遏索拉非尼诱导肝癌细胞死亡。进一步研究发现，索拉非尼可以：1.促进肝癌细胞中NLRP3炎性体的表达，且呈浓度依赖性；2.上调肝癌细胞中Caspases-1的表达水平；3.通过透射电镜证实其可以诱导肝癌细胞发生焦亡。另外利用流式细胞术表明，索拉菲尼可以呈浓度依赖地促进肝癌细胞中ROS累积，与NLRP3炎性体的表达趋势一致。充分表明了索拉非尼确实能够调控NLRP3炎性体形成及活化从而诱导肝癌细胞死亡。本研究明确索拉非尼激活NLRP3炎性体在调控肝癌细胞死亡及抗肿瘤治疗中的意义，为索拉非尼抗肝癌的分子机制提供新认识，并为肝癌的治疗及预后提供新靶点。