基于JAK2/STAT3/WASF3信号通路探讨清胰化积方抑制胰腺癌侵袭与转移的作用机制

According to theory of traditional Chinese medicine, the occurrence of pancreatic cancer is closely related to union of damp-heat toxins. In the previous studies, we discovered Qingyihuaji decoction (QYHJ) - a Chinese herbal medicine decoction based on heat-clearing and retention-removing drugs - can improve overall survival of advanced pancreatic cancer, and was found to be an independent protective factor of pancreatic cancer with liver metastases. Experimental study showed that Qingyihuaji decoction could inhibit cancer-related inflammation in tumors by decreasing infiltration of tumor-associated macrophages and IL-6 production, thus preventing pancreatic cancer progression. Accordingly we assumed that JAK2/STAT3 signal transduction pathway can be activated as IL-6 expression is downregulated by QYHJ, which also influence the downsteam gene such as MMPs, ICAM-1 and WASF3, and inhibit pancreatic cancer invasion and metastasis through "inflammation-associated carcinoma" chain. In view of the thought upward, we attempt to specify the influence of pancreatic cancer cell invasion, adhesion and motility treated by QYHJ at cellular level, and to reveal the mechanism of QYHJ inhibit pancreatic cancer invasion and metastasis through regulating JAK2/STAT3/WASF3 signal transduction pathway mediated by IL-6. Meanwhile we expected to verify the inhibitory effect of QYHJ for experimental pancreatic cancer with liver metastases by regulating this signal pathway at animal model level.

中医学认为，胰腺癌的发病与湿热毒邪互结密切相关。前期研究中我们发现，以清热消积为治法的清胰化积方能改善晚期胰腺癌总体生存期，为胰腺癌肝转移患者的预后保护性因素。动物实验证实清胰化积方在抑制胰腺癌的同时，可阻断肿瘤相关巨噬细胞浸润并下调IL-6表达而治疗肿瘤相关性炎症。据此我们假设，清胰化积方在下调IL-6表达时激活了JAK2/STAT3信号通路，并影响下游的MMPs、ICAM-1、WASF3等基因表达，通过“炎癌链”抑制胰腺癌侵袭与转移。基于上述思路，本课题试图在细胞水平上明确清胰化积方对人胰腺癌细胞体外侵袭、粘附与运动能力的影响，部分阐明该方调控IL-6介导的JAK2/STAT3/WASF3信号转导通路抑制胰腺癌侵袭与转移的机理；同时在动物模型上证实清胰化积方调控此信号通路对实验性胰腺癌肝转移的抑制作用。

IL-6及其介导的JAK2/STAT3信号通路在肿瘤侵袭与转移中具有重要意义。本课题通过基因表达调控技术，结合基本的分子生物学实验方法及动物实验，从细胞和分子水平对清胰化积方（QYHJ）调控JAK2/STAT3信号通路抑制胰腺癌转移的作用机制进行了初步研究。首先采用血清药理学方法制备了QYHJ含药血清，并对其主要成分加以定量分析与鉴定，确定了最佳给药方案与最佳取血时间。然后从细胞增殖、侵袭、粘附和迁移实验等角度分别论证了QYHJ对胰腺癌CFPAC-1细胞的抑制作用，且具有良好量效关系。QYHJ各剂量组均可下调胰腺癌CFPAC-1细胞JAK-2、STAT3、WASF3及其磷酸化蛋白表达水平，联合小分子抑制剂AZD1480后具有协同抑制作用；此外，QYHJ亦可抑制胰腺癌CFPAC-1细胞发生EMT，并与AZD1480具有协同作用。体内实验与体外实验结果基本吻合。综上，本研究为明确QYHJ调控JAK2/STAT3/WASF3信号通路抑制胰腺癌转移的机制奠定了坚实的工作基础，同时对于进一步探寻其最佳化学组分提供了重要参考依据。