基于IL-6/STAT3信号通路调控网络的白头翁皂苷抗炎-抗癌作用的相关性研究

Inflammation -- pushing occurrence and malignant evolution of tumor, and the IL-6/STAT3 signal transduction pathway is a key molecule in the chain of inflammation - cancer. Most heat-clearing and detoxifying herbs have both anti-inflammatory and anti-tumor effect. But whether its anti-tumor effect is related to its anti-inflammatory effect is still unknown. Heat-clearing and detoxifying herb Pulsatilla is selected as a model drug in this project due to the early work of a solid foundation and the exact role of anti-inflammatory and anti-tumor. Through the culture of tumor cells in simulated inflammatory environment in vitro and the establishment of colitis-associated animal models of colon cancer to observe the intervention of Pulsatilla on inflammation, tumor,and inflammation associated tumor.Using ELISA,PCR chip, Western-blotting and other modern molecular biology technique, and to investigate the molecular mechanism of regulation of molecule network through the IL-6/STAT3 pathway of Pulsatilla anti-inflammatory, anti-tumor and inhibition of inflammation-cancer transformation. With the expectation that it will provide a new idea to study on characteristics and targets of anti-tumor effect for heat-clearing and detoxifying herbs.And also to expect that it will provide a solid theoretical basis for developmengt and application in clinical of Pulsatilla saponin as the new anti-tumor drug.

炎症是肿瘤发生及恶性演进的推手,IL-6/STAT3信号通路是炎-癌链中的关键分子。清热解毒中药具有天然抗生素之美誉，且抗癌作用也确切，但其抗炎和抗癌的内在关系还鲜见报道。课题组前期大量研究发现，清热解毒中药白头翁皂苷既可以很好的治疗溃疡性结肠炎(可减少病变组织中IL-6的表达)，又可以治疗包括结肠癌在内的多种肿瘤。因此，本项目以白头翁皂苷为对象，选择国内外公认的经典炎-癌转变动物模型，及炎症环境下肿瘤细胞培养，从整体和细胞分子不同水平，观察白头翁皂苷对炎症、炎症相关性肿瘤及IL-6/STAT3信号通路的干预作用；并于体外给予IL-6和STAT3抑制剂，体内采用STAT3-/-小鼠建立炎-癌转变动物模型后，观察白头翁皂苷的作用变化，从分子水平验证白头翁皂苷通过调控IL-6/STAT3信号通路控制炎-癌转变的机制，阐明白头翁抗炎-抗癌的内在关系，为清热解毒中药抗肿瘤作用特点研究提供新思路。

炎症是肿瘤发生发展的重要机制，炎-癌转变机制已成为国内研究的热点。大部分清热解毒中药具有抗炎和抗肿瘤的作用，但其抗肿瘤作用是否与其抗炎作用有关还不得而知。本项目以有大量前期研究基础的白头翁皂苷为模式药物，体内选择国内外公认的经典炎-癌转变动物模型——结肠炎相关性结肠癌(CAC)小鼠模型，体外在炎症环境下肿瘤细胞培养，从整体和细胞分子不同水平，观察白头翁皂苷对炎症、炎症相关性肿瘤及IL-6/STAT3信号通路的干预作用，并通过干预STAT3的表达进行体内外进一步的分子验证。通过体内实验发现，随着小鼠体内炎症水平的逐步升高，肿瘤形成逐渐增加，炎症水平和肿瘤形成和发展成正相关，持续的炎症促成该模型小鼠结直肠成瘤率100%，而白头翁皂苷除了可以明显降低结肠炎小鼠的炎症水平外，还可以明显降低结肠炎相关性结肠癌小鼠外周血和结肠局部组织的炎症水平，使得小鼠结肠组织上肿瘤个数明显减少，具有较好的抑制炎-癌转变的作用，进一步的机制研究发现这一作用和白头翁皂苷可以抑制IL-6/STAT3信号通路的活化有关；通过体外实验也表明，白头翁皂苷B4可以抑制经IL-6刺激引起的HCT-116细胞STAT3的磷酸化及其路径成员GP-130, p-JAK2蛋白的表达从而抑制炎症因子的表达；体内外干预STAT3表达或活化后，发现白头翁皂苷抗炎作用消失，对结肠炎相关性结肠癌小鼠抑制肿瘤形成的作用也消失，进一步证明白头翁皂苷通过抗炎发挥抗炎-癌转变的作用和STAT3信号通路有关。通过本项目研究内容的实施，阐明了白头翁抗炎-抗癌的内在关系，为清热解毒中药抗肿瘤作用特点研究提供新思路。