白细胞介素-33调控肝癌干细胞活性的机制研究

Cancer stem cells play a pivotal role in tumor development and metastasis, resistance to chemotherapeutics. Interleukin-33 (IL-33), as a newly member of the IL-1 family of cytokines, participates in a variety of diseases such as hepatic fibrosis，inflammation and tumor. However, its role in the development of liver cancer is not clear. In previous study, the applicants demonstrated that the subcutaneous Hepa1-6 implanted tumors grew significantly faster in IL-33 transgenic mice than in the group of wild type. In addition, human recombinant IL-33 induced the expression of the genes involved in the stemness of liver cancer cells，stimulated liver cancer cell sphere formation and prevented doxorubicin-induced tumor apoptosis in vitro. Thus we raise the hypothesis that IL-33, as an important regulator in tumor microenvironment, regulates the stemness of liver cancer, consequently affecting tumor malignant. In this project, we will study this proposition with the experimental models of liver cancer constructed with IL-33 transgenic mice and nude mice, and performed the experiments of RNA interference and signal blockade with cell culture. By in vivo and in vitro studies, we will explore the source of the IL - 33 in the liver cancer tissue and investigate the mechanism that interleukin-33 regulates the stemness of liver cancer, which may provide a new effective target to treat liver cancer patients.

肿瘤干细胞是肿瘤发生和转移的罪魁祸首，也是产生耐药性的主要原因。近期报道显示白细胞介素-33 (IL-33)作为新型的细胞因子，参与肝纤维化、炎症肿瘤等多种疾病过程，但IL-33在肝癌的发生发展中的作用还不明确。申请人在前期研究中发现，皮下接种的小鼠肝癌细胞Hepa1-6在IL-33转基因小鼠组中的生长速度显著快于野生型小鼠组。此外，人源重组IL-33蛋白能诱导肝癌细胞的干细胞活性相关基因的表达，增强肝癌细胞的体外成球能力及对阿霉素的耐药性。因此我们提出假设：IL-33作为肿瘤微环境的重要调控因子，通过调控肝癌干细胞活性，促进肝癌进展。我们将利用IL-33转基因小鼠及裸鼠构建肝癌模型开展研究，并配合细胞水平的干扰RNA和信号通路阻断剂实验，阐明其调控肝癌干细胞活性的机制，为治疗肝癌提供潜在靶点。

肿瘤干细胞是肿瘤发生和转移的罪魁祸首，也是产生耐药性的主要原因。近期报道显示白细胞介素-33 (IL-33)作为新型的细胞因子，参与肝纤维化、炎症肿瘤等多种疾病过程，但IL-33在肝癌的发生发展中的作用还不明确。我们利用生物信息及临床样本分析，并结合小鼠及裸鼠构建肝癌皮下移植瘤模型，配合通过体外成球实验，体内致瘤实验，化疗药物耐药实验，肿瘤干细胞相关基因和蛋白的检测及肝癌干细胞标志物等肿瘤干细胞活性评估实验，并结合信号通路筛选验证及Luminex实验。我们发现肝癌外周血的ST2 mRNA及血浆浓度高于正常体检者，且与肝癌的转移相关；ST2 rs3821204增加了肝癌的易感性。我们发现皮下接种的肝癌细胞经IL-33处理后小鼠生长速度显著快于野生型小鼠组。而且人源重组IL-33蛋白能诱导肝癌细胞的干细胞活性相关基因和蛋白的表达，增强肝癌细胞的体外成球能力及对阿霉素的耐药性，且能刺激肝癌肿瘤干细胞标志物CD90的表达。对其进行进一步研究发现IL-33通过刺激肝癌细胞分泌TGF-β增加肝癌肿瘤干细胞活性，促进了肝癌的发生发展。这将是对肝癌病理机制的重要补充，有望为恶性肝癌的治疗提供新的理论依据，从而为肝癌的治疗提供潜在靶点。