Division of Cancer Biology CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow, 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Division of Cancer Biology CSIR-Central Drug Research Institute (CSIR-CDRI), Lucknow, 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Arch Biochem Biophys. 2023 Sep 1;745:109701. doi: 10.1016/j.abb.2023.109701. Epub 2023 Jul 25.
Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Cytochrome P450 2E1 (CYP2E1) is an enzyme, primarily involved in the metabolism of xenobiotics and procarcinogens. The present study was designed to investigate the potential role of CYP2E1 triggered endoplasmic reticulum stress in the progression of HCC through inhibition of apoptosis. In vitro CYP2E1 promotes HepG2 cell migration, reduced chromatin condensation, enhanced intracellular ROS accumulation and induce cell cycle progression. Conversely this effect was averted by CYP2E1 siRNA, selective inhibitor Diallyl sulphide (DAS) and antioxidants (vitamin C and E). In vivo Diethylnitrosamine (DEN) induced HCC rats showed decreased body weight and increased relative liver weight. Moreover, macro trabecular-massive HCC (MTM-HCC) histological subtyping showed pathological features like well-differentiated tumors, micro-trabecular and pseudo glandular patterns, megakaryocytes and cholestasis. Masson's trichrome staining revealed an intensive accumulation of collagen fibers in the extracellular matrix (ECM). Increased CYP2E1, VEGF and PCNA enhance the carcinogenicity as revealed in immunohistochemistry results. Immunoblot analysis showed reduced expression of copper-zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) in cytosolic as well as mitochondrial fraction of rat liver tissue respectively. Also, increased level of CYP2E1 stimulated the upregulation of unfolded proteins response (UPR) and ER stress-related proteins such as Glucose regulatory protein 78 (GRP78), activating transcription factor 6 (ATF6) and CCAAT enhancer-binding protein (C/EBP) homologous protein (CHOP). Meanwhile, CYP2E1 stimulated ER-stress reduces BCL2 and downregulates the cleaved caspase 3 thus suppresses apoptosis. in. Furthermore, immunofluorescence revealed increased expression level of α-SMA in the HCC rat liver tissue. The level of CYP2E1 mRNA was significantly increased. Altogether, these findings indicate that CYP2E1 has a dynamic role in the pathogenesis of HCC and might be a budding agent in liver carcinogenesis therapy.
肝细胞癌（HCC）是全球癌症相关死亡的主要原因。细胞色素 P450 2E1（CYP2E1）是一种酶，主要参与外源性物质和前致癌物的代谢。本研究旨在通过抑制细胞凋亡来研究 CYP2E1 引发的内质网应激在 HCC 进展中的潜在作用。在体外，CYP2E1 促进 HepG2 细胞迁移，减少染色质凝聚，增强细胞内 ROS 积累并诱导细胞周期进程。相反，这种作用可以通过 CYP2E1 siRNA、选择性抑制剂二烯丙基二硫化物（DAS）和抗氧化剂（维生素 C 和 E）来避免。在体内，二乙基亚硝胺（DEN）诱导的 HCC 大鼠表现出体重减轻和相对肝重增加。此外，大小梁-巨块型 HCC（MTM-HCC）组织学亚型表现出分化良好的肿瘤、微小梁和假腺状模式、巨核细胞和胆汁淤积等病理特征。Masson 三色染色显示细胞外基质（ECM）中胶原纤维的密集积累。免疫组织化学结果显示 CYP2E1、VEGF 和 PCNA 的增加增强了致癌性。免疫印迹分析显示，大鼠肝组织细胞质和线粒体部分的铜锌超氧化物歧化酶（CuZnSOD）和锰超氧化物歧化酶（MnSOD）表达降低。此外，CYP2E1 水平的升高刺激未折叠蛋白反应（UPR）和内质网应激相关蛋白的上调，如葡萄糖调节蛋白 78（GRP78）、激活转录因子 6（ATF6）和 CCAAT 增强子结合蛋白（C/EBP）同源蛋白（CHOP）。同时，CYP2E1 刺激 ER 应激降低 BCL2 并下调裂解的 caspase 3，从而抑制细胞凋亡。此外，免疫荧光显示 HCC 大鼠肝组织中α-SMA 的表达水平增加。CYP2E1mRNA 的水平显著增加。总之，这些发现表明 CYP2E1 在 HCC 的发病机制中具有动态作用，并且可能是肝致癌治疗中的一个新兴因素。
