健脾益气方通过IL-6/STAT3炎症信号通路抑制肝癌细胞Vimentin过度表达的机制研究

Chronic inflammation has been increasingly recognized to occur during the progression and metastasis of various carcinomas such as primary liver cancer (hepatocellular carcinoma), which is one of the most common cancers. Vimentin, a type III intermediate filament (IF) protein, was proven to a key player of the liver cancer microenvironment. In our previous studies, the overexpression of vimentin in DEN-induced rat hepatoma and TGF-β1-induced SMMC-7721 cells were observed, while significant reduction of vimentin protein levels by Jianpi Yiqi decoction (JPYQD). Furthermore, proteolytic digestion of vimentin by Caspase-3, and subsequent apoptosis were observed in MHCC-97H cells and TGF-β1-induced SMMC-7721 cells, after treatement with JPYQD. Importantly, aberrant activation of the IL-6/STAT3 pathway can promote overexpression of vimentin in tumor cells, through enhanced gene transcription of vimentin and downregulated expression of Caspase-3. We speculate that inhibition of the IL-6/STAT3 inflammatory signaling pathway and subsequent downregulated expression of vimentin will be observed in liver cancer cells, after treatement with JPYQD. Therefore, the IL-6/STAT3-vimentin signaling pathway will be examined in diethylnitrosamine (DEN)-induced hepatocarcinogenic rat models after treatment by JPYQD, and the same experiments will do in vitro. The role of decreased stringency of IL-6/STAT3-vimentin pathway will be elucidated after treatment by JPYQD. The results will provide new evidences for the clinic usage of the JPYQD.

慢性炎症与肝癌的发生发展及转移密切相关。健脾是目前中医临床防治肝癌的重要治则。前期研究发现健脾益气方可通过下调肝癌细胞Vimentin的过度表达有效参与炎症微环境的调节；而国内外研究表明IL-6/STAT3信号异常激活可能是肝癌细胞Vimentin过度表达的主要因素。因此我们推测健脾益气方可通过下调IL-6/STAT3炎症信号通路，抑制Vimentin在肝癌细胞内的过度表达，干预肝癌炎症微环境。本项目拟采用DEN诱导的大鼠肝炎-肝硬化-肝癌模型和IL-6诱导的人肝癌细胞HepG2，结合通路抑制剂，综合应用PCR、Western blot、ELISA等技术，研究健脾益气方干预对肝癌细胞IL-6/STAT3-Vimentin信号通路的影响，深入探讨健脾益气方防治肝癌的机制，为健脾治法的灵活运用及健脾类方药进一步开发应用提供基础研究支持。

肝癌是临床常见难治的恶性肿瘤，慢性炎症与肝癌的发生发展及转移密切相关。健脾是目前中医临床防治肝癌的重要治则。前期研究发现健脾益气方可通过下调肝癌细胞Vimentin（波形蛋白）的过度表达有效参与炎症微环境的调节；而国内外研究表明IL-6/STAT3信号异常激活可能是肝癌细胞Vimentin过度表达的主要因素。因此我们推测健脾益气方可能通过下调IL-6/STAT3炎症信号通路，抑制Vimentin在肝癌细胞内的过度表达，干预肝癌炎症微环境。本项目分别采用DEN诱导的大鼠肝炎-肝硬化-肝癌模型和IL-6诱导的人肝癌细胞HepG2，结合通路抑制剂C188-9（STAT3抑制剂）和SC144（gp130抑制剂），综合应用RT-qPCR、Western blot、ELISA等技术，研究健脾益气方干预对肝癌细胞IL-6/STAT3-Vimentin信号通路的影响，深入探讨健脾益气方防治肝癌的机制。研究结果表明，中、高剂量的健脾益气方可减弱肝癌大鼠肝功能的恶化，明显抑制肝癌细胞增殖与侵袭、促进其凋亡，明显抑制肝癌大鼠肝组织和人肝癌细胞IL-6/STAT3-Vimentin信号通路相关分子（如IL-6、p-JAK1、p-JAK2、gp130、p-STAT3、Vimentin）的相对表达量，证实了本项目工作假说的科学性。研究结果可为健脾治法的灵活运用及健脾类方药进一步开发应用提供基础研究支持。