雷一鸣 杨逸冬 谭嗣伟 林显艺 吴斌

【摘要】目的研究腫瘤坏死因子α（TNFα）通过内质网应激信号通路对肝癌细胞自噬和增殖的作用。方法利用免疫组织化学检测原发性肝细胞癌患者癌灶组织、配对的癌旁组织，以及肝血管瘤患者瘤旁正常肝组织中TNFα、BECN1、LC3B、PCNA的表达水平。用人源TNFα重组因子刺激肝癌细胞株HepG2后，通过蛋白免疫印迹法检测自噬相关蛋白BECN1、LC3B以及细胞增殖标志物PCNA表达水平，并利用自噬抑制剂3MA抑制HepG2细胞自噬后，检测TNFα刺激后的细胞活性及PCNA蛋白水平的改变情况。通过蛋白免疫印迹法检测TNFα刺激HepG2细胞后内质网应激通路相关蛋白eIF2α、peIF2α的表达水平。结果肝细胞癌患者癌灶和癌旁组织中TNFα、BECN1、LC3B、PCNA蛋白表达量均较正常人肝组织升高。TNFα刺激HepG2细胞后，细胞内BECN1、LC3B、PCNA蛋白表达水平升高，细胞活性增强，使用3MA 抑制HepG2细胞自噬后，细胞PCNA蛋白表达水平以及细胞活性下降，TNFα刺激HepG2细胞后内质网应激活性标志物eIF2α磷酸化水平明显增加。结论 TNFα通过内质网应激信号通路诱导肝癌细胞自噬，从而促进肝癌细胞的增殖。

【关键词】肝细胞癌；肿瘤坏死因子α；自噬；内质网应激

TNFα induces autophagy and promotes proliferation of liver cancer cells via ER stress signaling pathwayLei Yiming， Yang Yidong， Tan Siwei， Lin Xianyi， Wu Bin Department of Gastroenterology， the Third Affiliated Hospital of Sun Yatsen University， Guangzhou 510630， China

Corresponding author， Wu Bin， Email： binwu001@hotmailcom

【Abstract】ObjectiveTo investigate the effect of tumor necrosis factorα （TNFα） upon the autophagy and proliferation of liver cancer cells through endoplasmic reticulum stress signaling pathway MethodsThe expression levels of TNFα， BECN1， LC3B and PCNA in the cancerous and paracancerous tissues of patients with primary hepatocellular carcinoma， and the normal tissues adjacent to tumors of patients with hepatic hemangioma were determined by immunohistochemistry After the HepG2 was treated with recombinant human TNFα cytokine， the expression of autophagyrelated proteins of BECN1 and LC3B， and the cell proliferation marker of PCNA were quantitatively measured by Western blot After the treatment with autophagy inhibitor 3MA， the changes in the HepG2 cell viability and PCNA expression were observed following TNFα stimulation After the HepG2 cells were treated with TNFα， the expression levels of eIF2a and peIF2a related to the ER stress signaling pathway were detected by Western blot ResultsThe expression levels of TNFα， BECN1， LC3B and PCNA proteins in the cancerous and paracancerous tissues of hepatocellular carcinoma patients were significantly upregulated compared with those in the normal liver tissue Following the HepG2 cells were treated with TNFα， the expression levels of BECN1， LC3B and PCNA proteins were upregulated， and the cell viability was increased After the treatment with autophagy inhibitor 3MA， the expression of PCNA protein and cell viability were downregulated After the treatment with TNFα， the phosphorylated level of eIF2a was significantly enhanced ConclusionTNFα can induce the autophagy of liver cancer cells via the endoplasmic reticulum stress signaling pathway， thereby promoting the proliferation of liver cancer cells

【Key words】 Hepatocellular carcinoma； Tumor necrosis factorα； Autophagy；

Endoplasmic reticulum stress

原发性肝细胞癌是严重威胁人类生命健康的恶性肿瘤之一，尽管近年来该病的基础研究和临床研究均取得了巨大进展，但其防治效果仍不尽如人意，肝细胞癌相关分子机制仍未清楚是重要的原因之一。自噬是细胞在受到刺激后，吞噬体内细胞质或细胞器形成自噬体，自噬体内的内容物在溶酶体作用下降解、再利用的过程，可分为巨自噬、微自噬和分子伴侣介导的自噬[1]。……