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Background It has been reported that long-chain non-coding RNA (lncRNA) zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) is an oncogene in various cancers, including hepatocellular carcinoma (HCC). We investigated the role and mechanism of ZEB1-AS1 as a competitive endogenous RNA (ceRNA) combined with miR-23c in HCC cell proliferation and invasion. Methods QRT-PCR was used to detect ZEB1-AS1 and miR-23c expressions in HCC tissues and cells. The dual luciferase reporter assay detected the targeted regulation of miR-23c and ZEB1-AS1. We also performed the correlation analysis of their expression in HCC tissues by the Spearman’s correlation analysis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect the proliferation of hepatoma cells. Cell invasion was assessed by the Transwell assay. Results QRT-PCR results indicated ZEB1-AS1 was upregulated and miR-23c was downregulated in HCC tissues and cell lines. ZEB1-AS1 knockdown hampered the proliferation and invasion of HCC cells. Dual luciferase reporter assay showed that miR-23c is a target of ZEB1-AS1, and ZEB1-AS1 was significantly negatively correlated with the miR-23c expression in HCC tissues. The results of MTT and Transwell assay showed that miR-23c inhibition restored the inhibitory effect of ZEB1-AS1 knockdown on HCC cells proliferation and invasion. Conclusions As a ceRNA, lncRNA ZEB1-AS1 may play a vital role in inhibiting HCC progression through miR-23c, which will provide new clues and theoretical basis for the HCC diagnosis and treatment.

Background Glutathione S-transferase zeta 1 (GSTZ1) is the penultimate enzyme in phenylalanine/tyrosine catabolism. GSTZ1 is dysregulated in cancers; however, its role in tumorigenesis and progression of hepatocellular carcinoma (HCC) is largely unknown. We aimed to assess the role of GSTZ1 in HCC and to reveal the underlying mechanisms, which may contribute to finding a potential therapeutic strategy against HCC. Methods We first analyzed GSTZ1 expression levels in paired human HCC and adjacent normal tissue specimens and the prognostic effect of GSTZ1 on HCC patients. Thereafter, we evaluated the role of GSTZ1 in aerobic glycolysis in HCC cells on the basis of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Furthermore, we assessed the effect of GSTZ1 on HCC proliferation, glutathione (GSH) concentration, levels of reactive oxygen species (ROS), and nuclear factor erythroid 2-related factor 2 (NRF2) signaling via gain- and loss- of GSTZ1 function in vitro. Moreover, we investigated the effect of GSTZ1 on diethylnitrosamine (DEN) and carbon tetrachloride (CCl4) induced hepatocarcinogenesis in a mouse model of HCC. Results GSTZ1 was downregulated in HCC, thus indicating a poor prognosis. GSTZ1 deficiency significantly promoted hepatoma cell proliferation and aerobic glycolysis in HCC cells. Moreover, loss of GSTZ1 function depleted GSH, increased ROS levels, and enhanced lipid peroxidation, thus activating the NRF2-mediated antioxidant pathway. Furthermore, Gstz1 knockout in mice promoted DEN/CCl4-induced hepatocarcinogenesis via activation of the NRF2 signaling pathway. Furthermore, the antioxidant agent N-acetylcysteine and NRF2 inhibitor brusatol effectively suppressed the growth of Gstz1-knockout HepG2 cells and HCC progression in Gstz1−/− mice. Conclusions GSTZ1 serves as a tumor suppressor in HCC. GSH depletion caused by GSTZ1 deficiency elevates oxidative stress, thus constitutively activating the NRF2 antioxidant response pathway and accelerating HCC progression. Targeting the NRF2 signaling pathway may be a promising therapeutic approach for this subset of HCC.

// Ling Xu 1, 2, * , Weiqi Dai 1, * , JingJing Li 1, * , Lei He 1, * , Fan Wang 1 , Yujing Xia 1 , Kan Chen 1 , Sainan Li 1 , Tong Liu 1 , Jie Lu 1 , Yingqun Zhou 1 , Yugang Wang 2 , Chuanyong Guo 1 1 Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai 200072, China 2 Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China * These authors contributed equally to this work Correspondence to: Ling Xu, e-mail: xiaoling05@126.com Chuan-Yong Guo, e-mail: guochuanyong@hotmail.com Keywords: miR-124-1, hepatocellular carcinoma, methylation, CASC3 Received: October 10, 2015 Accepted: March 08, 2016 Published: March 22, 2016 ABSTRACT This study was to investigate the roles and mechanisms of miR-124-1 in hepatocellular carcinoma (HCC). We analyzed the expression of miR-124-1 in human HCC tissues and cell lines. Luciferase reporter assays were used to analyze the target of miR-124-1. Human HCC cell lines were transduced with lentiviruses expressing miR-124-1, and proliferation and colony formation were analyzed. The growth of human HCC cells overexpressing miR-124-1 was assessed in nude mice. The expression of p38-MAPK, JNK, ERK and related signaling molecules was detected by western blotting and immunohistochemistry. Our results showed that miR-124-1 levels were reduced in HCC tissues and cell lines compared with those in adjacent non-cancer tissues and normal liver cell lines respectively. Downregulation of miR-124-1 in HCC cell lines were attributed to hypermethylation of its promoter region. Overexpression of miR-124-1 inhibited HCC cell proliferation in vitro , whereas miR-124-1 was correlated with clinicopathological parameters of HCC patients. HCC cell-mediated overexpression of miR-124-1 in nude mice suppressed tumor growth. Cancer susceptibility candidate 3 (CASC3) was identified as a direct target of miR-124-1 by computational analysis and experimental assays. MiR-124-1-mediated downregulation of CASC3 resulted in the inactivation of p38-MAPK, JNK and ERK. Our findings provide potential new targets for the prevention or treatment of HCC.

Hepatocellular carcinoma (HCC) is the one of most common and deadly cancers, and is also highly resistant to conventional chemotherapy treatments. Mitochondrial phosphoglycerate mutase/protein phosphatase (PGAM5) regulates mitochondrial homeostasis and cell death, however, little is known about its roles in cancer. The aim of this study was to explore the clinical significance and potential biological functions of PGAM5 in hepatocellular carcinoma. For the first time, our results show that PGAM5 is significantly upregulated in HCC compared with corresponding adjacent noncancerous hepatic tissues and high PGAM5 expression is an independent predictor of reduced survival times in both univariate and multivariate analyses. Additionally, in vivo and in vitro studies showed that depleting PGAM5 expression inhibited tumor growth and increased the 5-fluorouracil sensitivity of HCC cells. Conversely, restoring PGAM5 expression in PGAM5-knockdown cells dramatically enhanced HCC cell resistance to 5-fluorouracil. Importantly, we demonstrated that the mechanism of 5-fluorouracil resistance conferred to HCC cells by PGAM5 was via inhibiting BAX- and cytochrome C-mediated apoptotic signaling by interacting and stabilizing Bcl-xL. Consistently, in the same cohorts of HCC patient tissues, Bcl-xL expression was positively correlated with PGAM5, and together predicted poor prognoses. In Conclusion, Our data highlight the molecular etiology and clinical significance of PGAM5 in HCC. Targeting the novel signaling pathway mediated by PGAM5/Bcl-xL may represent a new therapeutic strategy to improve the survival outcomes of HCC patients.