基于SphK1/S1P/YAP通路的黄芩苷对炎症相关性癌症的抑制作用及其机制研究

Currently, it is one of most potential strategies for cancer therapy to target the mechanism by which inflammation promotes cancer initiation and progression. Recent studies have reported that SphK1/S1P/YAP pathway plays an important role in the cancer initiation and progression driven by inflammation. Targeting SphK1/S1P/YAP pathway may be a new therapeutic strategy for inflammation-associated cancer. Baicalin exerts dramatic anti-inflammatory and anticancer activities. However, it still remains to be elucidated the potential mechanism of the inhibitory effects of baicalin on the initiation and progression in inflammation-associated cancer. Our previous study demonstrated that baicalin might exert anticancer effect on cancer cells in various culture system in vitro via SphK1/S1P/YAP pathway. This project aims to investigate the inhibitory effects of baicalin on the cancer initiation and progression of inflammation-associated cancer by establishing various culture system in vitro and building many kinds of inflammation-associated cancer in mice in vivo. Moreover, SphK1/S1P/YAP pathway is regarded as the breakthrough point, and we further explore the bridge role of Src in YAP activation induced by SphK1/S1P, to fully illustrate the anticancer mechanism of baicalin in the inflammatory microenvironment. In conclusion, this project provides theoretical basis for the anticancer mechanism research of baicalin, and gives new insight to the development of promising anticancer therapeutic agents.

基于炎症促进肿瘤发生发展的具体机制开发抗肿瘤新药，是当前极具潜力的癌症治疗策略之一。最近相关研究表明，SphK1/S1P/YAP通路在炎症促进肿瘤发生发展中发挥重要作用，靶向该通路将成为有效治疗炎症相关性癌症的新策略。黄芩苷具有显著的抗炎和抗肿瘤活性，但是黄芩苷对炎症相关性癌症的抑制作用及其机制，尚不明确，有待阐明。前期研究利用多种培养体系模拟肿瘤炎症微环境，发现黄芩苷可能通过调控SphK1/S1P/YAP通路发挥抗肿瘤作用。据此，本项目通过体外构建多种培养体系，体内建立多种小鼠炎症相关性癌症模型，研究黄芩苷对炎症相关性癌症发生发展的抑制作用，并以SphK1/S1P/YAP通路为切入点，阐明其作用机制，同时探索Src在SphK1/S1P诱导YAP活化中的桥梁作用。本项目为黄芩苷的抗肿瘤研究提供理论依据，并为抗肿瘤药物研发提供新的思路。

基于炎症促进肿瘤发生发展的具体机制开发抗肿瘤新药，是当前极具潜力的癌症治疗策略之一。最近相关研究表明，SphK1/S1P/YAP通路在炎症促进肿瘤发生发展中发挥重要作用，靶向该通路将成为有效治疗炎症相关性癌症的新策略。本项目体内建立AOM/DSS诱导的小鼠结肠炎相关性结直肠癌模型，体外建立体外条件培养和非接触共培养体系（利用PMA分化的THP-1巨噬细胞给予LPS刺激形成的上清条件培养肿瘤细胞，和构建基于transwell小室的非接触共培养体系），模拟肿瘤炎症微环境，在整体和细胞水平研究黄芩苷对结肠炎相关性结直肠癌发生发展的抑制作用。黄芩苷能够有效的提高AOM/DSS模型小鼠的生存率，明显减少AOM/DSS模型小鼠结肠上肿瘤的个数，有效抑制AOM/DSS模型小鼠结肠肿瘤的大小，从而抑制AOM/DSS模型小鼠结肠肿瘤的生长。条件培养和非接触共培养体系中，黄芩苷能够抑制结肠癌HCT116细胞的细胞活力，同时抑制结肠癌HCT116细胞Ki67表达而抑制其细胞增殖。非接触共培养体系中，黄芩苷能够抑制结肠癌HCT116细胞中细胞增殖相关蛋白CTGF和Cyr61的转录。Real-time PCR和Western Blot结果表明，条件培养体系中，黄芩苷能够抑制结肠癌HCT116细胞中细胞增殖相关蛋白CTGF和Cyr61的转录和表达。流式细胞术细胞周期检测结果表明，黄芩苷能够诱导结肠癌HCT116细胞发生G1/S期周期阻滞。体内外机制研究表明，黄芩苷能够抑制SphK1的表达，促进YAP丝氨酸127位点的磷酸化，从而抑制YAP的入核激活。黄芩苷能够抑制条件培养体系中结肠癌HCT116细胞S1P的分泌。分子对接分析显示，黄芩苷可以与SphK1形成稳定的相互作用，具有保守的氢键与疏水相互作用，可能是SphK1潜在的抑制剂。因此，黄芩苷通过调控SphK1/S1P/YAP信号通路发挥抗肿瘤作用。此外，本项目还发现其他中药天然产物的抗结肠炎作用，为结肠炎相关性结直肠癌的治疗提供新的候选化合物。综上所述，此项目为黄芩苷的抗肿瘤治疗提供新的研究思路和理论基础。