Yan Haixiong, Ma XiaoQian, Mi Ze, He Zhenhu, Rong Pengfei
Department of Radiology, The Third Xiangya Hospital of Central South University, Changsha, Hunan, China.
J Clin Transl Hepatol. 2022 Aug 28;10(4):608-619. doi: 10.14218/JCTH.2021.00301. Epub 2022 Feb 21.
This study was designed to uncover the mechanism for extracellular polysaccharide (EPS1-1)-mediated effects on hepatocellular carcinoma (HCC) development.
HCC cells were treated with EPS1-1, miR-494-3p mimic, sh-TRIM36, and pcDNA3.1-TRIM36. The levels of miR-494-3p and TRIM36 were measured in normal hepatocytes, THLE-2, and HepG2 and HuH7HCC cell lines, along with the protein expression of cyclin D/E and p21. The proliferation, cell cycle, and apoptosis of HCC cells were assayed. The interactions between miR-494-3p and TRIM36, and between TRIM36 and cyclin E were assessed. Finally, the expression and localization of TRIM36 and cyclin E were monitored, and tumor apoptosis was detected, in tumor xenograft model.
EPS1-1 suppressed HCC cell proliferation and cyclin D/E expression and promoted apoptosis and p21 expression. miR-494-3p was upregulated and TRIM36 was downregulated in HCC cells. Transfection with miR-494-3p mimic or sh-TRIM36 facilitated HCC cell proliferation and the expression of cyclin D/E protein but they inhibited apoptosis and p21 expression in the presence of EPS1-1. Overexpression of TRIM36 further consolidated EPS1-1-mediated inhibition of HCC proliferation, cyclin D/E, and the promotion of apoptosis and p21 expression. Those effects were reversed by miR-494-3p overexpression. TRIM36 was a target gene of miR-494-3p, and TRIM36 induced cyclin E ubiquitination. EPS1-1 suppressed cyclin E expression, promoted TRIM36 expression and tumor apoptosis, all of which were abrogated by increasing the expression of miR-494-3p .
EPS1-1 protected against HCC by limiting its proliferation and survival through the miR-494-3p/TRIM36 axis and by inducing cyclin E ubiquitination.
本研究旨在揭示细胞外多糖（EPS1-1）介导的对肝细胞癌（HCC）发展影响的机制。
用EPS1-1、miR-494-3p模拟物、sh-TRIM36和pcDNA3.1-TRIM36处理HCC细胞。在正常肝细胞、THLE-2以及HepG2和HuH7 HCC细胞系中检测miR-494-3p和TRIM36的水平，以及细胞周期蛋白D/E和p21的蛋白表达。检测HCC细胞的增殖、细胞周期和凋亡情况。评估miR-494-3p与TRIM36之间以及TRIM36与细胞周期蛋白E之间的相互作用。最后，在肿瘤异种移植模型中监测TRIM36和细胞周期蛋白E的表达及定位，并检测肿瘤凋亡情况。
EPS1-1抑制HCC细胞增殖和细胞周期蛋白D/E表达，促进凋亡和p21表达。HCC细胞中miR-494-3p上调而TRIM36下调。用miR-494-3p模拟物或sh-TRIM36转染促进了HCC细胞增殖和细胞周期蛋白D/E蛋白表达，但在存在EPS1-1的情况下它们抑制了凋亡和p21表达。TRIM36的过表达进一步巩固了EPS1-1介导的对HCC增殖、细胞周期蛋白D/E的抑制以及对凋亡和p21表达的促进作用。miR-494-3p过表达逆转了这些作用。TRIM36是miR-494-3p的靶基因，且TRIM36诱导细胞周期蛋白E泛素化。EPS1-1抑制细胞周期蛋白E表达，促进TRIM36表达和肿瘤凋亡，而增加miR-494-3p的表达可消除所有这些作用。
EPS1-1通过miR-494-3p/TRIM36轴限制HCC的增殖和存活并诱导细胞周期蛋白E泛素化，从而对HCC起到保护作用。
