内质网（ER）应激可以刺激肝细胞癌（HCC）细胞的增殖和转移，同时阻碍凋亡和免疫系统功能，但ER应激在HCC中的分子机制尚未完全研究。我们旨在通过降低ER应激相关降解蛋白的表达研究FAM134B抑制HCC细胞自噬的分子机制。收集了临床样本进行了本研究。培养了正常肝细胞株HL7702和Hep3B以及Huh7 HCC细胞株。构建了FAM134B沉默细胞株。使用CCK-8实验测量细胞增殖，使用板块集落形成实验检测细胞迁移和侵袭能力。采用流式细胞术检测凋亡率。采用透射电子显微镜观察自噬体的形成。使用qRT-PCR和WB检测与自噬相关蛋白的表达变化。最后，通过免疫组织化学观察相关蛋白的表达。结果显示，FAM134B在人类肝癌组织和HCC细胞株Hep3B和Huh7中的表达明显增加。将携带sh-FAM134B的腺相关病毒载体转染到Hep3B细胞中后，结果显示sh-FAM134B能够有效抑制Hep3B细胞增殖并促进HCC细胞凋亡。与此同时，sh-FAM134B能够有效诱导Hep3B肝癌细胞的自噬。免疫组织化学结果显示，sh-FAM134B可以有效诱导ER应激。FAM134B通过抑制DERL2、EDEM1、SEL1L和HRD1等与ER应激相关的降解因子的表达来抑制HCC细胞的自噬并促进肝癌的进展。© 2023 作者。细胞与分子医学杂志由细胞与分子医学基金会和约翰·威立出版社发表。

Endoplasmic reticulum (ER) stress can stimulate the proliferation and metastasis of hepatocellular carcinoma (HCC) cells while hindering apoptosis and immune system function, but the molecular mechanism of ER stress in HCC has yet to be fully studied. We aim to investigate the molecular mechanism by which FAM134B inhibits autophagy of HCC cells by reducing the expression of ER stress-related degradation proteins. Clinical samples were collected for this study. Normal liver cell lines HL7702 and Hep3B and Huh7 HCC cell lines were cultured. Construction of FAM134B knockdown cell line. Cell proliferation was measured using the CCK-8 assay, while cell migration and invasion capabilities were detected using the plate colony formation assay. Flow cytometry was used to detect the apoptosis rate. Transmission electron microscopy was used to observe the formation of autophagosomes. qRT-PCR and WB detective expression changes related to autophagy proteins. Finally, the expression of the relevant proteins was observed by immunohistochemistry. The expression of FAM134B was significantly increased in human liver cancer tissue and HCC cell lines Hep3B and Huh7. After the lentiviral vector was transfected into Hep3B cells with sh-FAM134B, results showed that sh-FAM134B could effectively inhibit Hep3B cell proliferation and promote HCC cell apoptosis. Meanwhile, sh-FAM134B could effectively induce the autophagy of Hep3B liver cancer cells. Immunohistochemistry results showed that sh-FAM134B could effectively induce ER stress. FAM134B inhibits HCC cell autophagy and promotes the progression of liver cancer by inhibiting the expression of ER stress-related degradation factors such as DERL2, EDEM1, SEL1L and HRD1.© 2023 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.