白头翁皂苷通过调控肿瘤微环境中TAMs表型M1/M2的转化干预结直肠癌发生发展的机制研究

At present, it is recognized that the occurrence and development of malignant tumors depend not only on the tumor cells themselves, but also on the microenvironment of tumor cells. The intervention of tumor microenvironment has become a hot topic in the research of cancer prevention and treatment. In 1992, Mantovani and other proposed the "macrophage balance hypothesis" that tumor associated macrophages (TAMs) have the dual function of tumor suppression and tumor growth. It was confirmed that M1 had anti tumor effect, while M2 had a tumor promoting effect. Our previous studies showed that the anticancer activity of total Saponin of Pulsatilla is better than the monomer composition. Some Saponin have cytotoxic effect, some Saponin can obviously increase the expression of inflammatory factors in macrophages, and others can also increase the ratio of CD4+/CD8+. According to these results, it is supposed that the saponins are involved in the regulation of the balance and conversion of M1 and M2 in tumor microenvironment. It have double effects of " restoring effects and eliminating evil ". Based on this, the subject is to study the relationship about growth of colon cancer cells and transformation of M1 and M2 macrophages, and study the intervening effect of Pulchinenoside in vivo and vitro. Thus, it might elucidate the regulation mechanism of anti-tumor effect of Pulsatilla Saponin about balance and conversion of M1 and M2 in colon cancer microenvironment.

目前人类认识到恶性肿瘤的发生发展不仅取决于肿瘤细胞本身，还与肿瘤细胞所在的微环境密切相关，干预肿瘤微环境成为当今肿瘤防治研究的一大热点。1992年Mantovani等提出“巨噬细胞平衡假说”，认为肿瘤相关巨噬细胞(TAMs)具有抑瘤和促瘤生长的双重作用。后经证实，TAMs的表型中M1具有抑瘤作用，而M2则具有促瘤作用。本课题组前期研究发现，白头翁总皂苷抗癌活性优于单体成分,且部分皂苷具有细胞毒作用，而部分皂苷能明显升高巨噬细胞炎症因子的表达，也能提高CD4+/CD8+比值，推测其参与调控肿瘤微环境中TAMs两种表型的平衡和转化，达到既提高免疫，又杀死癌细胞的“固本祛邪”双重功效。基于此，本课题利用体内外模型研究结肠癌细胞生长转移与M1/M2巨噬细胞极化的关系，及白头翁皂苷不同成分干预作用，从而阐明白头翁皂苷多成分调节结肠癌微环境中M1/M2的平衡与转化而发挥抗肿瘤作用。

1992年Mantovani等提出“ 巨噬细胞平衡假说”，认为肿瘤相关巨噬细胞(TAMs)具有抑瘤和促瘤生长的双重作用。后经证实，TAMs的表型中M1具有抑瘤作用，而M2则具有促瘤作用。本课题组前期研究发现，白头翁总皂苷抗癌活性优于单体成分,且部分皂苷具有细胞毒作用，而部分皂苷能明显升高巨噬细胞炎 症因子的表达，也能提高CD4+/CD8+比值，推测其参与调控肿瘤微环境中TAMs两种表型的平衡和转化，达到既提高免疫，又杀死癌细胞的“固本祛邪”双重功效。基于此，本课题利用体内外模型研究结肠癌和乳腺癌细胞生长转移与M1/M2巨噬细胞极化的关系，及白头翁皂苷不同成分调节肿瘤微环境中M1/M2的平衡与转化而发挥抗肿瘤作用机制。结果显示，通过白头翁调控巨噬细胞抗结直肠癌网络药理学以及白头翁活性成分对巨噬细胞极化影响的相关研究，最终筛选出白头翁皂苷A3与23-羟基白桦酸作为白头翁中能够调控巨噬细胞极化的有效成分用于后续抗肿瘤实验；23-羟基白桦酸通过调控巨噬细胞中JAK/STAT3/NF-kB/STAT1信号轴参与肿瘤微环境中TAMs表型M1/M2转化，从而发挥抗结直肠癌的作用；23-羟基白桦酸通过靶向STAT6蛋白抑制巨噬细胞M2极化，并减弱M2巨噬细胞对结直肠癌凋亡的抑制作用，从而恢复结直肠癌对化疗药5-FU的敏感性；23-HBA能够下调肿瘤内MDSC的比例及减弱MDSC的免疫抑制功能，从而恢复CD8+T细胞抗肿瘤活性，发挥抗结直肠癌作用。白头翁皂苷A3能够靶向TLR4蛋白促进巨噬细胞M1极化，从而产生具有细胞毒性杀伤作用的炎性因子IL-12，并下调了乳腺癌中VEGF的表达，从而发挥抗乳腺癌生长及血管生成的作用；白头翁皂苷A3通过靶向STAT3蛋白抑制巨噬细胞M2极化，从而发挥抗三阴性乳腺癌转移的作用。本课题从分子水平阐明白头翁主要有效成分白头翁皂苷A3与23-羟基白桦酸调控肿瘤微环境中肿瘤相关巨噬细胞极化的作用和抗肿瘤作用特点,为清热解毒中药通过影响肿瘤免疫微环境而抗肿瘤作用研究提供新思路。