scholarly journals lncRNA SNHG8 Promotes the Tumorigenesis and Metastasis by Sponging miR-149-5p and Predicts Tumor Recurrence in Hepatocellular Carcinoma

2018 ◽  
Vol 51 (5) ◽  
pp. 2262-2274 ◽  
Author(s):  
Jiayong Dong ◽  
Fei Teng ◽  
Wenyuan Guo ◽  
Jinghui Yang ◽  
Guoshan Ding ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Lung Metastasis ◽  
Tumor Recurrence ◽  
Molecular Mechanisms ◽  
The Cancer Genome Atlas ◽  
Luciferase Reporter ◽  
Pcr Analysis ◽  
Potential Candidate ◽  
Mesenchymal Transition ◽  
Hcc Cells

Background/Aims: Long noncoding RNAs (lncRNAs) are aberrantly expressed in multiple malignant tumors involved in tumor growth and metastasis. Accumulating data show that small nucleolar RNA host gene (SNHG) 1/12/20 plays a key role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which SNHG8 contributes to HCC remain elusive and merit exploration. Methods: The association between SNHG8 expression and the clinicopathological characteristics and prognoses in HCC patients was analysed by using qRT-PCR analysis and the data from The Cancer Genome Atlas. Cell growth and metastatic potential were determined by MTT, colony formation, Transwell assays, and the mouse xenograft tumor model and lung metastasis model. Epithelial–mesenchymal transition markers were detected by western blot analysis. The binding capacity of SNHG8 with miRNAs was evidenced by bioinformatic analysis and a luciferase reporter assay. In addition, the rescue experiments were performed based on co-transfection with sh-SNHG8 and a miR-149 inhibitor in HCC cells. Results: The expression levels of lncRNA SNHG8 were dramatically increased in HCC tissues and cell lines as compared with the adjacent normal tissues, and SNHG8 expression was an independent prognostic factor of tumor recurrence in HCC patients. Furthermore, knockdown of SNHG8 inhibited cell proliferation, invasion, and lung metastasis in vitro and in vivo, whereas overexpression of SNHG8 reversed these effects. SNHG8 acted as a sponge of miR-149 and counteracted the tumor suppressive effects of mi R-149 in HCC cells. Expression of phosphatase, Mg2+/Mn2+ dependent 1F, a target of R-149, displayed a negative correlation with miR-149 expression but a positive correlation with SNHG8 expression in HCC specimens. Conclusion: As lncRNA SNHG8 may promote HCC tumorigenesis and metastasis by sponging miR-149, it is a potential candidate marker and therapeutic target for HCC.

scholarly journals Sulfatase 2-Induced Cancer-Associated Fibroblasts Promote Hepatocellular Carcinoma Progression via Inhibition of Apoptosis and Induction of Epithelial-to-Mesenchymal Transition

2021 ◽  
Vol 9 ◽  
Author(s):  
Cong Wang ◽  
Chuzhi Shang ◽  
Xiaohong Gai ◽  
Tao Song ◽  
Shaoshan Han ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Signaling Pathway ◽  
Epithelial To Mesenchymal Transition ◽  
Akt Signaling ◽  
The Cancer Genome Atlas ◽  
Luciferase Reporter ◽  
Akt Signaling Pathway ◽  
Mesenchymal Transition ◽  
Hcc Cells

BackgroundSulfatase 2 (SULF2) removes the 6-O-sulfate groups from heparan sulfate proteoglycans (HSPG) and consequently alters the binding sites for various signaling molecules. Here, we elucidated the role of SULF2 in the differentiation of hepatic stellate cells (HSCs) into carcinoma-associated fibroblasts (CAFs) in the hepatocellular carcinoma (HCC) microenvironment and the mechanism underlying CAF-mediated HCC growth.MethodsThe clinical relevance of SULF2 and CAFs was examined using in silico and immunohistochemical (IHC) analyses. Functional studies were performed to evaluate the role of SULF2 in the differentiation of HSCs into CAFs and elucidate the mechanism underlying CAF-mediated HCC growth. Mechanistic studies were performed using the chromatin immunoprecipitation, luciferase reporter, and RNA immunoprecipitation assays. The in vitro findings were verified using the nude HCC xenograft mouse model.ResultsThe Cancer Genome Atlas (TCGA) database and IHC analyses revealed that the expression of CAF markers, which was positively correlated with that of SULF2 in the HCC tissues, predicted unfavorable postsurgical outcomes. Co-culturing HSCs with HCC cells expressing SULF2 promoted CAF differentiation. Additionally, CAFs repressed HCC cell apoptosis by activating the SDF-1/CXCR4/PI3K/AKT signaling pathway. Meanwhile, SULF2-induced CAFs promoted epithelial-to-mesenchymal transition (EMT) of HCC cells by modulating the SDF-1/CXCR4/OIP5-AS1/miR-153-3p/SNAI1 axis. Studies using HCC xenograft mouse models demonstrated that OIP5-AS1 induced EMT by upregulating SNAI1 and promoted HCC growth in vivo.ConclusionThese data indicated that SULF2 secreted by the HCC cells induced the differentiation of HSCs into CAFs through the TGFβ1/SMAD3 signaling pathway. SULF2-induced CAFs attenuated HCC apoptosis by activating the SDF-1/CXCR4/PI3K/AKT signaling pathway and induced EMT through the SDF-1/CXCR4/OIP5-AS1/miR-153-3p/SNAI1 axis. This study revealed a novel mechanism involved in the crosstalk between HCC cells and CAFs in the tumor microenvironment, which can aid in the development of novel and efficient therapeutic strategies for primary liver cancer.

scholarly journals Potential Role of microRNA-183 as a Tumor Suppressor in Hepatocellular Carcinoma

2018 ◽  
Vol 51 (5) ◽  
pp. 2065-2072 ◽  
Author(s):  
Wei Bian ◽  
Hongfei Zhang ◽  
Miao Tang ◽  
Shaojun Zhang ◽  
Lichao Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepg2 Cells ◽  
Molecular Mechanisms ◽  
The Cancer Genome Atlas ◽  
Migration And Invasion ◽  
Metastatic Progression ◽  
Mesenchymal Transition ◽  
Reporter Assays

Background/Aims: Disseminated tumors, known as metastases, are responsible for ninety-percent of mortality due to cancer. Epithelial to mesenchymal transition, a phenomenon required for morphological conversion of non-motile discoid shaped epithelial cells to highly motile spindle-shaped mesenchymal cells, is thought to be a pre-requisite for metastatic progression. Metastasis-associated 1 (MTA1) protein is a prime inducer of EMT and metastatic progression in all solid tumors including hepatocellular carcinoma (HCC). However, the molecular mechanisms that regulate the expression and function of MTA1 in HCC have not been elucidated. Methods: In silico prediction algorithms were used to find microRNAs (miRNAs) that may target MTA1. We examined the relationship between the expression of MTA1 and miR-183 using quantitative real time PCR. We also determined the levels of the MTA1 protein using immunohistochemistry. Reporter assays, in the presence and absence of the miR-183 mimic, were used to confirm MTA1 as a bona fide target of miR183. The effect of miR-183 on HCC pathogenesis was determined using a combination of in vitro migration and invasion assay, together with in vivo xenograft experiments. The correlation between miR-183 and MTA1 expression was also studied in samples from HCC patients, and in The Cancer Genome Atlas dataset. Results: Analysis of the sequence database revealed that MTA1 is a putative target of miR-183. MTA1 protein and RNA expression showed opposite trends to miR-183 expression in breast, renal, prostate, and testicular tissue samples from cancer patients, and in the metastatic HCC cell line HepG2. An inverse correlation was also observed between MTA1 (high) and miR-183 (low) expression within samples from HHC patients and in the TCGA dataset. Reporter assays in HepG2 cells showed that miR-183 could inhibit translation of a reporter harboring the wild-type, but not the mutant miR-183 3’-untranslated region (UTR). In addition, miR-183 significantly inhibited in vitro migration and invasion in HepG2 cells, and in vivo hepatic metastasis. Conclusion: Our results reveal a novel post-transcriptional regulatory mechanism for MTA1 expression via miR-183, which is suppressed during HCC pathogenesis.

scholarly journals MicroRNA-587 Functions as a Tumor Suppressor in Hepatocellular Carcinoma by Targeting Ribosomal Protein SA

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Miao Chen ◽  
Duo Wang ◽  
Junjie Liu ◽  
Zhizhan Zhou ◽  
Zhanling Ding ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Ribosomal Protein ◽  
Cellular Function ◽  
The Cancer Genome Atlas ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Pcr Analysis ◽  
Qrt Pcr ◽  
Geo Database

Background. Hepatocellular carcinoma (HCC) is one of the most highly aggressive cancer worldwide with an extremely poor prognosis. Evidence has revealed that microRNA-587 (miR-587) is abnormally expressed in a series of cancers. However, its expressions and functions in HCC have not been clearly acknowledged. Methods. We detected the expression level of miR-587 both in the Gene Expression Omnibus (GEO) database and 86 paired clinical HCC tissues together with paired adjacent normal tissues by quantitative real-time PCR (qRT-PCR). Afterwards, the transfected HCC cell line SMMC-7721 cells were collected for the cell proliferation assay, cell-cycle arrest, cell migration, and invasion assays to explore the roles of miR-587 in regulating cellular function. In addition, bioinformatics analysis, combined with qRT-PCR and dual-luciferase reporter assays, were performed to confirm whether ribosomal protein SA (RPSA) mRNA was the direct target gene of miR-587. Moreover, the Cancer Genome Atlas (TCGA) and GEO databases as well as 86 paired clinical HCC tissues were used to verify the negative regulation between miR-587 and RPSA. Results. In the present study, both the GEO database (GSE36915 and GSE74618) analysis and qRT-PCR analysis of 86 paired clinical tissues showed that miR-587 was significantly downregulated in HCC tissues. The overexpression of miR-587 inhibited proliferation, cell cycle, migration, and invasion in SMMC-7721 cells. In addition, miR-587 directly interacted with the 3′-untranslated region (UTR) of RPSA. Moreover, miR-587 overexpression directly suppressed RPSA expression, and the two genes were inversely expressed in HCC based on the analyses in TCGA and GEO (GSE36376) databases and qPCR analysis of 86 paired clinical tissues. Conclusion. Our results demonstrate that miR-587 is downexpressed in HCC and regulates the cellular function by targeting RPSA.

scholarly journals HDAC9 Is Preferentially Expressed in Dedifferentiated Hepatocellular Carcinoma Cells and Is Involved in an Anchorage-Independent Growth

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2734
Author(s):  
Keita Kanki ◽  
Ryota Watanabe ◽  
Le Nguyen Thai ◽  
Chun-Hao Zhao ◽  
Kyoko Naito
Keyword(s):  
Hepatocellular Carcinoma ◽  
Histone Deacetylases ◽  
Epithelial Mesenchymal Transition ◽  
Cell Transformation ◽  
The Cancer Genome Atlas ◽  
Hepatic Differentiation ◽  
Differentiation Markers ◽  
Mesenchymal Transition ◽  
Cancer Genome Atlas ◽  
Hcc Cells

Aberrant activation of histone deacetylases (HDACs) is one of the causes of tumor cell transformation in many types of cancer, however, the critical HDAC responsible for the malignant transformation remain unclear. To identify the HDAC related to the dedifferentiation of hepatocellular carcinoma (HCC) cells, we investigated the expression profile of HDACs in differentiated and undifferentiated hepatoma cells. We found that HDAC9, a member of the class II HDAC, is preferentially expressed in undifferentiated HCC cells. Analysis of 373 HCC patients in The Cancer Genome Atlas (TCGA) database revealed that the expression of HDAC9 mRNA positively correlated with the markers of mesenchymal phenotype and stemness, and conversely, negatively correlated with hepatic differentiation markers. HDAC9 was transcriptionally upregulated in epithelial–mesenchymal transition (EMT)-induced HCC cells treated with TGF-β. Genetic and pharmacological inhibition of HDAC9 in undifferentiated HCC cells showed decreased sphere-forming activity, which indicates an ability of anchorage-independent cell growth and self-renewal. We also showed that aldehyde dehydrogenase 1A3 (ALDH1A3) was downregulated in HDAC9-suppressing cells, and ALDH inhibitor disulfiram significantly decreased the sphere formation of undifferentiated HCC cells. Together, our data provide useful information for the development of HDAC9-specific inhibitors for the treatment of HCC progression.

scholarly journals LncRNA ZFPM2-AS1 Promotes Metastasis and Epithelial-mesenchymal Transition of Hepatocellular Carcinoma via Targeting miR-3612/ADAM15 Axis

2020 ◽  
Author(s):  
Nan Yang ◽  
Tianxiang Chen ◽  
Bowen Yao ◽  
Liang Wang ◽  
Runkun Liu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Biological Effects ◽  
Luciferase Reporter Assay ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Reporter Assay ◽  
Mesenchymal Transition ◽  
Hcc Cells

Abstract Background: Long non-coding RNAs (lncRNAs) have obtained growing attention due to their potential effects as novel regulators in various tumors. This study aimed to investigate the expression and roles of lncRNA ZFPM2-AS1 in the progression of hepatocellular carcinoma (HCC). Methods: Transwell was used to determine migration and invasion of HCC cells in vitro. The lung metastasis mouse model was established to detect tumor metastasis of HCC in vivo. The direct binding of miR-3612 to 3'UTR of DAM15 was confirmed by luciferase reporter assay. The expression of ZFPM2-AS1 and miR-3612 in HCC specimens and cell lines were detected by real-time PCR. The correlation among ZFPM2-AS1 and miR-3612 were disclosed by a dual-luciferase reporter assay, RIP assay and biotin pull-down assay.Results: In present study, we found that ZFPM2-AS1 was up-regulated in HCC tissues and cells and its upregulation was associated with TNM stage, vascular invasion, and poor prognosis of HCC patients. Functionally, gain- and loss-of-function experiments indicated that ZFPM2-AS1 promoted cell migration, invasion and EMT progress in vitro and in vivo. ZFPM2-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-3612 in HCC cells. Mechanically, miR-3612 inhibited HCC metastasis and alternation of miR-3612 reversed the promotive effects of ZFPM2-AS1 on HCC cells. In addition, we confirmed that ADAM15 was a direct target of miR-3612 in HCC and mediated the biological effects of miR-3612 and ZFPM2-AS1 in HCC. Curcumin, an active derivative from turmeric, exerts its anticancer effects through ZFPM2-AS1/miR-3612/ADAM15 pathway. Our data identified ZFPM2-AS1 as a novel oncogenic lncRNA and correlated malignant clinical outcomes in HCC patients. Conclusions: ZFPM2-AS1 performed as oncogenic role via targeting miR-3612 and subsequently promoted ADAM15 expression in HCC. Our results revealed that ZFPM2-AS1 could be a potential prognostic biomarker and therapeutic target for HCC.

scholarly journals Epigenetic regulation of ferroptosis via ETS1/miR-23a-3p/ACSL4 axis mediates sorafenib resistance in human hepatocellular carcinoma

2022 ◽  
Vol 41 (1) ◽  
Author(s):  
Yuanjun Lu ◽  
Yau-Tuen Chan ◽  
Hor-Yue Tan ◽  
Cheng Zhang ◽  
Wei Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Resistance ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

Abstract Background Drug resistance to sorafenib greatly limited the benefits of treatment in patients with hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) participate in the development of drug resistance. The key miRNA regulators related to the clinical outcome of sorafenib treatment and their molecular mechanisms remain to be identified. Methods The clinical significance of miRNA-related epigenetic changes in sorafenib-resistant HCC was evaluated by analyzing publicly available databases and in-house human HCC tissues. The biological functions of miR-23a-3p were investigated both in vitro and in vivo. Proteomics and bioinformatics analyses were conducted to identify the mechanisms that regulating miR-23a-3p. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to validate the binding relationship of miR-23a-3p and its targets. Results We found that miR-23a-3p was the most prominent miRNA in HCC, which was overexpressed in sorafenib non-responders and indicated poor survival and HCC relapse. Sorafenib-resistant cells exhibited increased miR-23a-3p transcription in an ETS Proto-Oncogene 1 (ETS1)-dependent manner. CRISPR-Cas9 knockout of miR-23a-3p improved sorafenib response in HCC cells as well as orthotopic HCC tumours. Proteomics analysis suggested that sorafenib-induced ferroptosis was the key pathway suppressed by miR-23a-3p with reduced cellular iron accumulation and lipid peroxidation. MiR-23a-3p directly targeted the 3′-untranslated regions (UTR) of ACSL4, the key positive regulator of ferroptosis. The miR-23a-3p inhibitor rescued ACSL4 expression and induced ferrotoptic cell death in sorafenib-treated HCC cells. The co-delivery of ACSL4 siRNA and miR-23a-3p inhibitor abolished sorafenib response. Conclusion Our study demonstrates that ETS1/miR-23a-3p/ACSL4 axis contributes to sorafenib resistance in HCC through regulating ferroptosis. Our findings suggest that miR-23a-3p could be a potential target to improve sorafenib responsiveness in HCC patients.

scholarly journals eIF6 Promotes the Malignant Progression of Human Hepatocellular Carcinoma via the mTOR Signaling Pathway

2020 ◽  
Author(s):  
Liping Sun ◽  
Shuguang Liu ◽  
Xiaopai Wang ◽  
Xuefeng Zheng ◽  
Ya Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Signaling Pathway ◽  
Prognostic Value ◽  
Molecular Mechanisms ◽  
Protein Translation ◽  
Translation Initiation Factor ◽  
Gene Set Enrichment Analysis ◽  
The Cancer Genome Atlas ◽  
Initiation Factor ◽  
Hcc Cells

Abstract Background Eukaryotic translation initiation factor 6 (eIF6) has a crucial function in the maturation of 60S ribosomal subunits, and it controls the initiation of protein translation. Although emerging studies indicate that eIF6 is aberrantly expressed in various types of cancers, the functions and underlying molecular mechanisms of eIF6 in the pathological progression of hepatocellular carcinoma (HCC) remain unclear. This study aimed to evaluate the potential diagnostic and prognostic value of eIF6 in patients with HCC. Methods HCC samples enrolled from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and our cohort were used to explore the role and mechanism of eIF6 in HCC. The diagnostic power of eIF6 was verified by receiver operating characteristic curve (ROC) analysis and its prognostic value was assessed by Kaplan-Meier analysis, and then related biological functions of eIF6 were determined in vitro and in vivo cancer models. In addition, potential molecular mechanism of eIF6 in HCC was unveiled by the gene set enrichment analysis and western blot assay. Results We demonstrated that eIF6 expression was markedly increased in HCC, and elevated eIF6 expression correlated with pathological progression of HCC. Besides, eIF6 served as not only a new diagnostic biomarker but also an independent risk factor for OS in HCC patients. Functional studies indicated that the deletion of eIF6 displayed tumor-suppressor activity in HCC cells. Furthermore, we found that eIF6 could activate the mTOR-related signaling pathway and regulate the expression level of its target genes, such as CCND1, CDK4, CDK6, MYC, CASP3 and CTNNBL1, and these activities promoted proliferation and invasion of HCC cells. Conclusions The findings of this study provided a novel basis for understanding the potential role of eIF6 in promoting tumor growth and invasion, and exploited a promising strategy for improving diagnosis and prognosis of HCC.

scholarly journals CircRNA LRIG3 knockdown inhibits hepatocellular carcinoma progression by regulating miR-223-3p and MAPK/ERK pathway

2021 ◽  
Author(s):  
Hui Sun ◽  
Junwei Zhai ◽  
Li Zhang ◽  
Yingnan Chen
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Mitogen Activated Protein Kinase ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Erk Pathway ◽  
Mitogen Activated Protein ◽  
Hcc Cells

IntroductionEmerging evidence suggests that circular RNAs (circRNAs) play critical roles in tumorigenesis. However, the roles and molecular mechanisms of circRNA leucine-rich repeat immunoglobulin domain-containing protein 3 (circ_LRIG3) in hepatocellular carcinoma (HCC) has not been investigated.Material and methodsThe expression levels of circ_LRIG3, miR-223-3p, and mitogen-activated protein kinase kinase 6 (MAP2K6) were determined by qRT-PCR. Flow cytometry was applied to determine the cell cycle distribution and apoptosis. Cell proliferation, migration and invasion were assessed by MTT, colony formation, and transwell assays. Western blot assay was employed to measure the protein levels of the snail, E-cadherin, MAP2K6, mitogen-activated protein kinase (MAPK), phospho-MAPK (p-MAPK), extracellular signal-regulated kinases (ERKs), and phospho-ERKs (p- ERKs). The relationship between miR-223-3p and circ_LRIG3 or MAP2K6 was predicted by bioinformatics tools and verified by dual-luciferase reporter assay. A xenograft tumor model was established to confirm the functions of circ_LRIG3 in vivo.ResultsCirc_LRIG3 and MAP2K6 expression were enhanced while miR-223-3p abundance was reduced in HCC tissues and cells. Knockdown of circ_LRIG3 inhibited cell proliferation, metastasis, and increasing apoptosis. MiR-223-3p was a target of circ_LRIG3, and its downregulation reversed the inhibitory effect of circ_LRIG3 knockdown on the progression of HCC cells. Moreover, MAP2K6 could bind to miR-223-3p, and MAP2K6 upregulation also abolished the suppressive impact of circ_LRIG3 interference on progression of HCC cells. Additionally, the silence of circ_LRIG3 suppressed the activation of the MAPK/ERK pathway and tumor growth by upregulating miR-223-3p and downregulating MAP2K6.ConclusionsCirc_LRIG3 knockdown inhibited HCC progression through regulating miR-223-3p/MAP2K6 axis and inactivating MAPK/ERK pathway.

scholarly journals Epigenetic silencing of ZIC4 contributes to cancer progression in hepatocellular carcinoma

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Wenbiao Chen ◽  
Donge Tang ◽  
Dongxin Tang ◽  
Yong Dai
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Progression ◽  
Promoter Region ◽  
Developmental Process ◽  
Epithelial Mesenchymal Transition ◽  
Epigenetic Silencing ◽  
The Cancer Genome Atlas ◽  
Mesenchymal Transition ◽  
Hcc Cells

Abstract Inactivation of tumor suppressor gene played critical roles in the development and progression of human hepatocellular carcinoma (HCC). Zic family member 4 (ZIC4) is transcription factor and plays an important role in the developmental process. However, the expression and biological role of ZIC4 in HCC is poorly understood. Here, bioinformatics analysis based on The Cancer Genome Atlas (TCGA) database revealed an aberrant hypermethylation of ZIC4 in HCC. ZIC4 is frequently hypermethylated in promoter region and down expressed in HCC cells and tissues. Functionally, ZIC4 inhibition facilitated the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Conversely, ZIC4 overexpression reduced proliferation and invasiveness of HCC cells. In addition, ZIC4 inhibition rescued the antitumor effect induced by enhancer of zeste homolog 2 (EZH2) knockdown or EZH2 inhibitor. Mechanistically, EZH2 knockdown or EZH2 inhibitor reduced the enrichment of EZH2 and H3K27me3 in ZIC4 promoter region and leading to the upregulation of ZIC4. Altogether, these data indicate that epigenetic silencing of ZIC4 by EZH2 mediated H3K27me3 is an important mechanism in HCC and provide a new therapeutic target for the treatment of hepatocellular carcinoma disease.

scholarly journals Hypoxia Accelerates Aggressiveness of Hepatocellular Carcinoma Cells Involving Oxidative Stress, Epithelial-Mesenchymal Transition and Non-Canonical Hedgehog Signaling

2017 ◽  
Vol 44 (5) ◽  
pp. 1856-1868 ◽  
Author(s):  
Zhikui Liu ◽  
Kangsheng Tu ◽  
Yufeng Wang ◽  
Bowen Yao ◽  
Qing Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Migration And Invasion ◽  
Ros Production ◽  
Mesenchymal Transition ◽  
Gli1 Expression ◽  
Hh Signaling ◽  
Hcc Cells

Background/Aims: Hypoxic microenvironment, a common feature of hepatocellular carcinoma (HCC), can induce HIF-1α expression and promote the epithelial-mesenchymal transition (EMT) and invasion of cancer cells. However, the underlying molecular mechanisms have not fully elucidated. Methods: HCC cells were cultured under controlled hypoxia conditions or normoxic conditions. Transwell assays were used to examine the migration and invasion capacity. HIF-1α siRNA, cyclopamine (a SMO antagonist) and GLI1 siRNA were used to inhibit HIF-1α transcription or Hh signaling activation. Results: In present study, we first observed a strongly positive correlation between HIF-1α and GLI1 expression in HCC tissues. Then, we showed that hypoxia significantly promoted EMT process and invasion of HCC cells, associated with activating the non-canonical Hh pathway without affecting SHH and PTCH1 expression. HIF-1α knockdown mitigated hypoxia-induced SMO and GLI1 expression, EMT invasion of HCC cells. Moreover, the SMO inhibitor or GLI1 siRNA also reversed the hypoxia-driven EMT and invasion of HCC cells under hypoxia condition. Here, we show that non-canonical Hh signaling is required as an important role to switch on hypoxia-induced EMT and invasion in HCC cells. In addition, we found that hypoxia increased ROS production and that ROS inhibitors (NAC) blocked GLI1-dependent EMT process and invasion under hypoxic conditions. To determine a major route of ROS production, we tested whether nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) is involved in hypoxia-induced ROS production. NOX4 expression was found to be increased at both mRNA and protein levels in hypoxic HCC cells. Furthermore, siRNA-mediated knockdown of NOX4 expression abolished hypoxia induced ROS generation and GLI1-dependent activation and invasion of HCC cells. Conclusion: Our findings indicate that hypoxia triggers ROS-mediated GLI1-dependent EMT progress and invasion of HCC cells through induction of NOX4 expression. Thus, hypoxia-driven ROS mediated non-canonical Hh signaling may play an important role in the initiation of EMT and provides a potential marker for cancer prevention and treatment.

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