Role of epithelial to mesenchymal transition in hepatocellular carcinoma

Combined functional genomic and chemical screens identify SETD8 as a therapeutic target in MYC-driven medulloblastoma

Medulloblastoma (MB) is the most prevalent malignant brain tumor in children, accounting for 20% of all childhood brain tumors. The molecular profiling of MB into 4 major subgroups (WNT, SHH, Grp3, and Grp4) emphasizes the heterogeneity of MB and opens paths in which treatments may be targeted to molecularly aggressive and distinct tumors. Current therapeutic strategies for Group 3 MB are challenging and can be accompanied by long-term side effects from treatment. The involvement of altered epigenetic machinery in neoplastic transformation in MB has become more evident. Thus, we performed an epigenomic RNAi and chemical screen and identified SETD8/PRE-SET7/KMT5a as a critical player in maintaining proliferation and cell survival of MB cells. We have found that inhibition of SETD8 effects the migration/invasive ability of MB cells. SETD8 alters H4K20me chromatin occupancy at key genes involved in tumor invasiveness and pluripotency. Interestingly, these results link the aggressive and metastatic behavior of MYC-driven MB with SETD8 activity. Based on our results, we suggest that SETD8 has a critical role mediating Group 3 MB tumorigenesis. Establishing a role for SETD8 as a factor in MYC-driven MB has potential to lead to more effective therapies needed to improve outcomes in high-risk patients.

Plasminogen activator inhibitor 2 (PAI2) inhibits invasive potential of hepatocellular carcinoma cells in vitro via uPA- and RB/E2F1-related mechanisms

BACKGROUND

Plasminogen activator inhibitor 2 (PAI2) has been shown to be associated with invasive phenotypes and prognosis in hepatocellular carcinoma (HCC). However, its biological roles and underlying mechanisms in invasion of HCC have not been explored. The present study aimed to address the issues.

METHODS

First, sub-lines in that PAI2 was stably overexpressed and silenced were established based on MHCC97H and BEL7402 cell lines, respectively. Wound-healing and transwell assays were applied to evaluate cell migration and invasion. Urokinase-type plasminogen activator (uPA) activity was measured using an ELISA kit. Real-time RT-PCR and western blotting were used to show gene expression at mRNA and protein levels. E2F1 expression in human specimens was determined by tissue microarray-based immunohistochemical staining.

RESULTS

The sub-lines, MHCC97H-PAI2 and BEL7402-siPAI2, were successfully established. The two sub-lines carried much lower and higher migration and invasion powers, respectively, in contrast to the controls. In MHCC97H-PAI2 sub-line, intra-medium uPA activity was significantly decreased, while RB expression was obviously elevated, compared with the controls. The BEL7402-siPAI2 sub-line presented the opposite trend. To identify the role of RB/E2F1 pathway, we transiently overexpressed E2F1 in MHCC97H-PAI2 sub-line, and largely reversed the inhibitory effects of PAI2 on cell migration and invasion, through regulating multiple matrix metalloproteinases and epithelial-mesenchymal transition. In HCC specimens, E2F1 expression was much higher in tumor than in non-tumor tissues, and was significantly related to Edmondson-Steiner grade, overall as well as tumor-free survival.

CONCLUSIONS

Our data suggest that PAI2 inhibits invasive potential of HCC cells via uPA- and RB/E2F1-related mechanisms.

Cytochrome P450 family members are associated with fast-growing hepatocellular carcinoma and patient survival: An integrated analysis of gene expression profiles

BACKGROUND/AIMS

The biological heterogeneity of hepatocellular carcinoma (HCC) makes prognosis difficult. Although many molecular tools have been developed to assist in stratification and prediction of patients by using microarray analysis, the classification and prediction are still improvable because the high-through microarray contains a large amount of information. Meanwhile, gene expression patterns and their prognostic value for HCC have not been systematically investigated. In order to explore new molecular diagnostic and prognostic biomarkers, the gene expression profiles between HCCs and adjacent nontumor tissues were systematically analyzed in the present study.

MATERIALS AND METHODS

In this study, gene expression profiles were obtained by repurposing five Gene Expression Omnibus databases. Differentially expressed genes were identified by using robust rank aggregation method. Three datasets (GSE14520, GSE36376, and GSE54236) were used to validate the associations between cytochrome P450 (CYP) family genes and HCC. GSE14520 was used as the training set. GSE36376 and GSE54236 were considered as the testing sets.

RESULTS

From the training set, a four-CYP gene signature was constructed to discriminate between HCC and nontumor tissues with an area under curve (AUC) of 0.991. Accuracy of this four-gene signature was validated in two testing sets (AUCs for them were 0.973 and 0.852, respectively). Moreover, this gene signature had a good performance to make a distinction between fast-growing HCC and slow-growing HCC (AUC = 0.898), especially for its high sensitivity of 95%. At last, CYP2C8 was identified as an independent risk factor of recurrence-free survival (hazard ratio [HR] =0.865, 95% confidence interval [CI], 0.754-0.992, P = 0.038) and overall survival (HR = 0.849; 95% CI, 0.716-0.995, P = 0.033).

CONCLUSIONS

In summary, our results confirmed for the first time that a four-CYP gene (CYP1A2, CYP2E1, CYP2A7, and PTGIS) signature is associated with fast-growing HCC, and CYP2C8 is associated with patient survival. Our findings could help to identify HCC patients at high risk of rapid growth and recurrence.

Transforming Growth Factor-β Promotes Morphomechanical Effects Involved in Epithelial to Mesenchymal Transition in Living Hepatocellular Carcinoma

The epithelial mesenchymal transition (EMT) is a physiological multistep process involving epithelial cells acquiring a mesenchymal-like phenotype. It is widely demonstrated that EMT is linked to tumor progression and metastasis. The transforming growth factor (TGF)-β pathways have been widely investigated, but its role in the hepatocarcinoma EMT is still unclear. While the biochemical pathways have been extensively studied, the alteration of biomechanical behavior correlated to cellular phenotype and motility is not yet fully understood. To better define the involvement of TGF-β1 in the metastatic progression process in different hepatocarcinoma cell lines (HepG2, PLC/PRF/5, HLE), we applied a systematic morphomechanical approach in order to investigate the physical and the structural characteristics. In addition, we evaluated the antitumor effect of LY2157299, a TGF-βR1 kinase inhibitor, from a biomechanical point of view, using Atomic Force and Confocal Microscopy. Our approach allows for validation of biological data, therefore it may be used in the future as a diagnostic tool to be combined with conventional biomolecular techniques.

Dynamics of Axl Receptor Shedding in Hepatocellular Carcinoma and Its Implication for Theranostics

Signaling of the receptor tyrosine kinase Axl and its ligand Gas6 is crucially involved in the development of liver fibrosis and hepatocellular carcinoma (HCC) by activation of hepatic stellate cells and modulation of hepatocyte differentiation. Shedding of Axl’s ectodomain leads to the release of soluble Axl (sAxl), which is increased in advanced fibrosis and in early-to-late stage HCC in the presence and absence of cirrhosis. Here, we focus on the dynamics of Axl receptor shedding and delineate possible scenarios how Axl signaling might act as driver of fibrosis progression and HCC development. Based on experimental and clinical data, we discuss the consequences of modifying Axl signaling by sAxl cleavage, as well as cellular strategies to escape from antagonizing effects of Axl shedding by the involvement of the hepatic microenvironment. We emphasize a correlation between free Gas6 and free sAxl levels favoring abundant Gas6/Axl signaling in advanced fibrosis and HCC. The raised scenario provides a solid basis for theranostics allowing the use of sAxl as an accurate diagnostic biomarker of liver cirrhosis and HCC, as well as Axl receptor signaling for therapeutic intervention in stratified HCC patients.

Profilin 1, negatively regulated by microRNA-19a-3p, serves as a tumor suppressor in human hepatocellular carcinoma

Profilin 1 (PFN1) is a critical actin-regulatory protein; however, its functional role in hepatocellular carcinoma (HCC) progression remains to be further elucidated. In the present study, we observed that the expression levels of PFN1 were significantly decreased in HCC tissues and cell lines. Low PFN1 expression was significantly correlated with aggressive clinicopathological characteristics and poor prognosis of HCC patients. Further in vitro experiments demonstrated that overexpression of PFN1 remarkably inhibited the proliferation, migration, invasion and EMT of HCC cells. Moreover, we also found that PFN1 was a direct target gene of miR-19a-3p, and in HCC tissues, and there was a significantly inverse correlation between PFN1 mRNA and miR-19a-3p expression. Collectively, our results showed that PFN1 functions as a tumor suppressor in HCC, and might serve as a diagnostic and therapeutic target for HCC patients.

Sorafenib and Carfilzomib Synergistically Inhibit the Proliferation, Survival, and Metastasis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and deadly human cancers. The 5-year survival rate is very low. Unfortunately, there are few efficacious therapeutic options. Until recently, Sorafenib has been the only available systemic drug for advanced HCC. However, it has very limited survival benefits, and new therapies are urgently needed. In this study, we investigated the anti-HCC activity of carfilzomib, a second-generation, irreversible proteasome inhibitor, as a single agent and in combination with sorafenib. In vitro, we found that carfilzomib has moderate anticancer activity toward liver cancer cells, but strongly enhances the ability of sorafenib to suppress HCC cell growth, proliferation, migration, invasion, and survival. Remarkably, the drug combination exhibits even more potent antitumor activity when tested in animal tumor models. Mechanistically, the combined treatment activates caspase-dependent and endoplasmic reticulum stress/CHOP-mediated apoptotic pathways, and suppresses epithelial-mesenchymal transition. In conclusion, our results demonstrate that the combination of carfilzomib and sorafenib has synergistic antitumor activities against HCC, providing a potential therapeutic strategy to improve the mortality and morbidity of HCC patients.

Spotlight on Bortezomib: potential in the treatment of hepatocellular carcinoma

INTRODUCTION

This study reviews the evidence for the use of Bortezomib (BZB), a first-in-class proteasome inhibitor in advanced Hepatocellular carcinoma (HCC). This review aims to delineate the role of BZB within the management of non-surgical and metastatic HCC, either as an alternative or as an adjunct to the current treatment paradigm.

AREAS COVERED

In addition to BZB pharmacology and mechanism of action, safety and tolerance profiles of the drug obtained from clinical trials are explored. The utility of BZB as a therapeutic agent either alone or in combination with other therapies against HCC, including its application in both preclinical and clinical settings has been reviewed. In particular, we highlight the importance of preclinical evaluation of BZB as a combinatorial agent in synergism with other therapies for the use in the management of HCC.

EXPERT OPINION

There has been much interest surrounding the use of BZB, a first-in-class proteasome inhibitor for HCC therapy. The discernment of outcomes of BZB clinical trials for HCC need to take into consideration the disease-specific factors that can affect survival outcomes including patient selection and aetiological differences. Further preclinical testing of BZB in combination with other therapeutic modalities can be important for eliciting enhanced anti-HCC effects.

Super-Enhancer-Associated Long Noncoding RNA HCCL5 Is Activated by ZEB1 and Promotes the Malignancy of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most dominant causes of neoplasm-related deaths worldwide. In this study, we identify and characterize HCCL5, a novel cytoplasmic long noncoding RNA (lncRNA), as a crucial oncogene in HCC. HCCL5 promoted cell growth, G₁-S transition, invasion, and metastasis while inhibiting apoptosis of HCC cells both in vitro and in vivo. Moreover, HCCL5 was upregulated in TGF-β1-induced classical epithelial-to-mesenchymal transition (EMT) models, and this lncRNA in turn accelerated the EMT phenotype by upregulating the expression of transcription factors Snail, Slug, ZEB1, and Twist1. HCCL5 was transcriptionally driven by ZEB1 via a super-enhancer and was significantly and frequently overexpressed in human HCC tissues, correlating with worse overall survival of patients with HCC. Together, this study characterizes HCCL5 as a super-enhancer-driven lncRNA promoting HCC cell viability, migration, and EMT. Our data also suggest that HCCL5 may serve as a novel prognostic biomarker and therapeutic target in HCC. SIGNIFICANCE: These findings identify the lncRNA HCCL5 as a super-enhancer-driven oncogenic factor that promotes the malignancy of hepatocellular carcinoma.

ZNF32 induces anoikis resistance through maintaining redox homeostasis and activating Src/FAK signaling in hepatocellular carcinoma

Tumor cells need to attain anoikis resistance to survive prior to metastasis making it a vital trait of malignancy. The molecular mechanism by which hepatocellular carcinoma (HCC) cells resist anoikis remains not fully understood. Here, we report that ZNF32 expression is markedly upregulated in HCC cells upon detachment. Enforced ZNF32 expression significantly promotes the anchorage-independent growth capability of HepG2 and Huh7 cells, whereas knockdown of ZNF32 results in increased apoptosis of HCC cells after detachment. Mechanistically, we demonstrate that ZNF32 overexpression suppresses the reactive oxygen species (ROS) accumulation and maintains mitochondrial membrane potential, leading to ATP, GSH and NADPH elevation and promoting HCC cell survival in response to suspension. Moreover, ZNF32 enhances the phosphorylation and activation of Src/FAK signaling. Src and FAK inhibitors effectively reverse ZNF32-induced anoikis resistance in HCC cells. Collectively, our findings not only reveal a novel and important mechanism by which ZNF32 contributes to anoikis resistance through maintaining redox homeostasis and activating Src/FAK signaling, but also suggest the potential therapeutic value of ZNF32 in HCC patients.

Aberrant Metabolism in Hepatocellular Carcinoma Provides Diagnostic and Therapeutic Opportunities

Hepatocellular carcinoma (HCC) accounts for over 80% of liver cancer cases and is highly malignant, recurrent, drug-resistant, and often diagnosed in the advanced stage. It is clear that early diagnosis and a better understanding of molecular mechanisms contributing to HCC progression is clinically urgent. Metabolic alterations clearly characterize HCC tumors. Numerous clinical parameters currently used to assess liver functions reflect changes in both enzyme activity and metabolites. Indeed, differences in glucose and acetate utilization are used as a valid clinical tool for stratifying patients with HCC. Moreover, increased serum lactate can distinguish HCC from normal subjects, and serum lactate dehydrogenase is used as a prognostic indicator for HCC patients under therapy. Currently, the emerging field of metabolomics that allows metabolite analysis in biological fluids is a powerful method for discovering new biomarkers. Several metabolic targets have been identified by metabolomics approaches, and these could be used as biomarkers in HCC. Moreover, the integration of different omics approaches could provide useful information on the metabolic pathways at the systems level. In this review, we provided an overview of the metabolic characteristics of HCC considering also the reciprocal influences between the metabolism of cancer cells and their microenvironment. Moreover, we also highlighted the interaction between hepatic metabolite production and their serum revelations through metabolomics researches.

Activated hepatic stellate cells promote epithelial-to-mesenchymal transition in hepatocellular carcinoma through transglutaminase 2-induced pseudohypoxia

Activation of hepatic stellate cells reportedly contributes to progression of hepatocellular carcinoma (HCC). Herein, we use quantitative proteomics and ingenuity pathway analysis to show that transglutaminase 2 (TGM2) is upregulated in the course of activated hepatic stellate cells promoting epithelial-mesenchymal transition (EMT) in HCC-derived cells both in vivo and in vitro. Mechanistically, activated hepatic stellate cells promote TGM2 upregulation in HCC cells through inflammatory signalling; and TGM2-induced depletion of von Hippel-Lindau (VHL) protein, a key molecule in the degradation of hypoxia inducible factor-1a (HIF-1a) under normoxia, then causes HIF-1a to accumulate, thereby producing a pseudohypoxic state that promotes EMT in HCC cells. These findings suggest that the promotion of EMT in HCC cells by activated hepatic stellate cells is mediated by pseudohypoxia induced via TGM2/VHL/HIF-1a pathway.

Hui Ma et al. report a new mechanism by which activated hepatic stellate cells promote the epithelial-to-mesenchymal transition (EMT) in hepatocellular carcinoma. They find that transglutaminase 2 is upregulated by activated hepatic stellate cells via inflammatory signalling, which leads to a pseudohypoxic state promoting EMT.

Generation and characterization of hepatocellular carcinoma cell lines with enhanced cancer stem cell potential

Hepatocellular carcinoma (HCC) is one of the most common causes for cancer-related death worldwide with rapidly increasing incidence and mortality rates. As for other types of cancers, also in HCC cancer stem cells (CSCs) are thought to be responsible for tumour initiation, progression and therapy failure. However, as rare subpopulations of tumour tissue, CSCs are difficult to isolate, thus making the development of suitable and reliable model systems necessary. In our study, we generated HepG2 subclones with enriched CSC potential by application of the spheroid formation method and subsequent single-cell cloning. Analyses in several 2D and 3D cell culture systems as well as a panel of functional assays both in vitro and in vivo revealed that the generated subclones displayed characteristic and sustained features of tumour initiating cells as well as highly aggressive properties related to tumour progression and metastasis. These characteristics could clearly be correlated with the expression of CSC markers that might have prognostic value in the clinical HCC setting. Therefore, we conclude that our CSC enriched HepG2 clones certainly represent suitable model systems to study the role of CSCs during HCC initiation, progression and drug resistance.

Long non-coding RNA CRNDE promotes the proliferation, migration and invasion of hepatocellular carcinoma cells through miR-217/MAPK1 axis

Hepatocellular carcinoma (HCC) is an invasive malignant tumour and the second major cause of cancer‐related deaths over the world. CRNDE and miR‐217 are non‐coding RNAs which play critical roles in cell growth, proliferation, migration. Mitogen‐activated protein kinase 1 (MAPK1) also participates in cancer cell process. Hence, this study aimed at investigating the effect of CRNDE on migration and invasion of HCC and figuring out the role of miR‐217 and MAPK1 in this process. The overexpression of CRNDE was demonstrated by a microarray‐based lncRNA profiling study. CRNDE expression in HCC was verified by qRT‐PCR. MTT assay and BrdU staining were applied to detect cell proliferation level. Transwell assay was utilized to examine cell migration and invasiveness abilities. Wound healing assay was performed for further exploration of cell migration capacity. MiR‐217 was predicted by bioinformatics. The dual luciferase reporter assay was performed to corroborate the targeting relationship between CRNDE, miR‐217 and MAPK1. MAPK1, the downstream target of miR‐217, was predicted using bioinformatics and was further confirmed by qRT‐PCR and Western blot. The interaction between CRNDE, miR‐217 and MAPK1 was studied by qRT‐PCR, Western blot, MTT, BrdU, transwell assay and wound healing assay. CRNDE was up‐regulated in HCC tissues and HCC cell lines. The high expression of CRNDE facilitated cell proliferation, migration and invasion, while the inhibited one affected on the contrary. MiR‐217, negatively correlated with CRNDE expression, was the target of CRNDE and was more lowly expressed in HCC. With the high expression of miR‐217, HCC cell proliferation, migration and invasion were suppressed. MAPK1, the possible target of miR‐217, was negatively correlated with miR‐217 but positively correlated with CRNDE and had the same effect in HCC formation process as CRNDE. Long non‐coding RNA CRNDE promotes the proliferation, migration and invasion of HCC cells through miR‐217/MAPK1 axis.

KDM6B promotes ovarian cancer cell migration and invasion by induced transforming growth factor-β1 expression

KDM6B, also known as JMJD3, is a member of the family of histone lysine demethylase (KDMs), which is closely related to many types of cancers. However, its role and the underlying mechanisms in ovarian cancer remain unknown. Here we show that KDM6B is elevated in epithelial ovarian cancer and its expression level is closely related with metastasis and invasion. In addition, survival analysis showed that high expression of KDM6B was associated with low overall survival in ovarian cancer patients. Overexpression of KDM6B in epithelial ovarian cancer cells promoted proliferation, epithelial-mesenchymal transition (EMT), migration and invasion in vitro, and enhanced metastatic capacities in vivo. On the contrary, silencing KDM6B in invasive and metastatic ovarian cancer cells inhibited these processes. Mechanistically, we found that KDM6B exerts its function by modulating the transforming growth factor-β1 (TGF-β1) expression, and TGF-β1 signal pathway inhibitor LY2157299 significantly inhibited KDM6B-induced proliferation, migration, metastasis, and EMT in ovarian cancer cells. Our findings, for the first time, reveal the pivotal role of KDM6B in the invasion and metastatic behavior of epithelial ovarian cancer. Thus, targeting KDM6B may be a useful strategy to interfere with these behaviors of epithelial ovarian cancer.

Transforming Growth Factor-β-Induced Cell Plasticity in Liver Fibrosis and Hepatocarcinogenesis

The Transforming Growth Factor-beta (TGF-β) family plays relevant roles in the regulation of different cellular processes that are essential for tissue and organ homeostasis. In the case of the liver, TGF-β signaling participates in different stages of disease progression, from initial liver injury toward fibrosis, cirrhosis and cancer. When a chronic injury takes place, mobilization of lymphocytes and other inflammatory cells occur, thus setting the stage for persistence of an inflammatory response. Macrophages produce profibrotic mediators, among them, TGF-β, which is responsible for activation -transdifferentiation- of quiescent hepatic stellate cells (HSC) to a myofibroblast (MFB) phenotype. MFBs are the principal source of extracellular matrix protein (ECM) accumulation and prominent mediators of fibrogenesis. TGF-β also mediates an epithelial-mesenchymal transition (EMT) process in hepatocytes that may contribute, directly or indirectly, to increase the MFB population. In hepatocarcinogenesis, TGF-β plays a dual role, behaving as a suppressor factor at early stages, but contributing to later tumor progression, once cells escape from its cytostatic effects. As part of its potential pro-tumorigenic actions, TGF-β induces EMT in liver tumor cells, which increases its pro-migratory and invasive potential. In parallel, TGF-β also induces changes in tumor cell plasticity, conferring properties of a migratory tumor initiating cell (TIC). The main aim of this review is to shed light about the pleiotropic actions of TGF-β that explain its effects on the different liver cell populations. The cross-talk with other signaling pathways that contribute to TGF-β effects, in particular the Epidermal Growth Factor Receptor (EGFR), will be presented. Finally, we will discuss the rationale for targeting the TGF-β pathway in liver pathologies.

Anti-IL-20 monoclonal antibody suppresses hepatocellular carcinoma progression

Interleukin (IL)-20 is a member of the IL-10 family of cytokines, which has been reported to participate in autoimmune inflammatory diseases. However, the potential role of IL-20 in hepatocellular carcinoma (HCC) progression has not yet been investigated. In the present study, it was observed that IL-20 mRNA and protein levels were markedly increased in the HCC tissues examined via reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining. In addition, IL-20 expression was significantly associated with tumor size, metastasis, TNM stage and poor prognosis in patients with HCC. Mouse recombinant IL-20 (mIL-20) enhanced liver cancer cell proliferation, migration and invasion in vitro, while the anti-IL-20 monoclonal antibody (mAb) attenuated the effect of mIL-20, inhibiting cancer cell migration and invasion in vitro and suppressing cell growth in vitro and in vivo. This was detected by Cell Counting Kit-8, colony formation, Transwell assays and a xenograft tumor nude mouse model. Western blotting revealed that IL-20 promoted HCC progression through inducing transforming growth factor-β and matrix metalloproteinase 9 expression and enhancing the phosphorylation of Jun N-terminal kinase and signal transducer and activator of transcription 3. The results of the present study indicated that IL-20 promotes HCC development. In addition, anti-IL-20 mAb may attenuate the effect of IL-20 and suppress liver tumorigenesis in vitro and in vivo, indicating that anti-IL-20 mAbs may potentially serve as effective therapeutic agents for HCC.

Trends in hepatocellular carcinoma research from 2008 to 2017: a bibliometric analysis

Objectives

To comprehensively analyse the global scientific outputs of hepatocellular carcinoma (HCC) research.

Methods

Data of publications were downloaded from the Web of Science Core Collection. We used CiteSpace IV and Excel 2016 to analyse literature information, including journals, countries/regions, institutes, authors, citation reports and research frontiers.

Results

Until March 31, 2018, a total of 24,331 papers in HCC research were identified as published between 2008 and 2017. Oncotarget published the most papers. China contributed the most publications and the United States occupied leading positions in H-index value and the number of ESI top papers. Llovet JM owned the highest co-citations. The keyword “transarterial chemoembolization” ranked first in the research front-line.

Conclusions

The amount of papers published in HCC research has kept increasing since 2008. China showed vast progress in HCC research, but the United States was still the dominant country. Transarterial chemoembolization, epithelial-mesenchymal transition, and cancer stem cell were the latest research frontiers and should be paid more attention.

CCR7 preservation via histone deacetylase inhibition promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells

The effects of Histone deacetylase (HDAC) inhibition on epithelial-mesenchymal transition (EMT) differs in various types of cancers. However, its function in hepatocellular carcinoma (HCC) is not well-explored. In this study, we investigated the effect of HDAC inhibition on EMT in HCC cells by using trichostatin A (TSA) and valproic acid (VPA). The results showed that TSA/VPA significantly induced EMT phenotype, as demonstrated by the decreased level of E-cadherin, increased level of N-cadherin, vimentin, Twist and snail, and enhanced capacity of cell migration and invasion. In addition, CCR7 was speculated and confirmed as a function target of HDAC inhibition. CCR7 promotes the progression of HCC and is associated with poor survival. Knockdown of CCR7 significantly attenuated the effect of TSA on EMT. Moreover, our results demonstrated that HDAC inhibition up-regulates CCR7 via reversing the promoter hypoacetylation and increasing CCR7 transcription. Taken together, our study has identified the function of HDAC in EMT of HCC and suggested a novel mechanism through which TSA/VPA exerts its carcinogenic roles in HCC. HDAC inhibitors require careful caution before their application as new anticancer drugs.

The functional role of exosome in hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide with limited therapeutic options. Exosome is a member of extracellular vesicles that can be released by different cells in liver to communicate with other cells. HCC development has been characterized by a dysfunction of exosome regulation through many molecular mechanisms. The aim of the present review is to summarize the literature on exosomes in HCC, their roles in hepatocarcinogenesis from liver disease, molecules exchange between tumor cells and neighboring cells, metastasis, chemoresistant, immunosuppression, early diagnose and therapy application.

METHODS

Literatures about HCC and exosomes from PubMed databases were reviewed in this article.

RESULTS

As our review described, exosomes can induce malignant transformation of liver disease via promoting viral diffusion and inflammation, exchange oncogenic factors between tumor cells, sustain tumor growth by neighboring stromal cells, play a important role in metastasis, trigger chemoresistance through transmitting long noncoding RNAs, stimulate immune activation as well as immune evasion, be utilized in biomarkers discovery and therapeutic options.

CONCLUSIONS

Available data suggested that exosomes may play an important role in HCC development. More studies on the way that exosomes mediated the HCC progression are needed to promote the clinical utilization of exosomes.

ARP3 promotes tumor metastasis and predicts a poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Therefore, the study of the precise molecular mechanism underlying hepatocarcinogenesis has profound significance. In this study, we found that the expression of ARP3 was significantly up-regulated in HCC tissues and cell lines. Studies in liver cancer specimens showed that the expression of ARP3 is closely related to the pathological grade, distant metastasis and vascular invasion of HCC. According to the results of multivariate analysis, ARP3 is an independent prognostic factor for HCC patients. In vitro, knockdown of ARP3 expression significantly inhibited the invasion and migration of HCC cells and altered the expression of EMT markers. Based on the above conclusions, we conclude that ARP3 may be a potential prognostic indicator and therapeutic target for HCC patients.

A novel multimarker assay for the phenotypic profiling of circulating tumor cells in hepatocellular carcinoma

Current clinicopathologic staging systems and serum biomarkers poorly discriminate tumor biology in hepatocellular carcinoma (HCC), with high recurrence rates following curative-intent surgical resection and liver transplantation (LT). Identification of accurate biomarkers for improved prognostication and treatment selection is a critical unmet need. We sought to develop a novel "liquid-biopsy" assay capable of detecting HCC circulating tumor cells (CTCs) and characterizing phenotypic subpopulations with prognostic significance. Using HCC cell lines, a tissue microarray, and human blood samples, an antibody cocktail targeting the cell-surface markers asialoglycoprotein receptor (ASGPR), glypican-3, and epithelial cell adhesion molecule was optimized for HCC CTC capture using the NanoVelcro CTC Assay. The ability of HCC CTCs and vimentin (VIM)-positive CTCs (a subpopulation expressing an epithelial-to-mesenchymal phenotype) to accurately discriminate tumor stage, recurrence, progression, and overall survival (OS) was evaluated in a prospective study of 80 patients. Multimarker capture detected greater numbers of CTCs than any individual antibody alone for both cell line and patient samples (P < 0.001). HCC CTCs were identified in 59/61 (97%) patients, and HCC (median, 6 CTCs) and non-HCC patients (median, 1 CTC; area under the receiver operating characteristic curve [AUROC] = 0.92; P < 0.001; sensitivity = 84.2%; specificity = 88.5%) were accurately discriminated. VIM-positive CTCs accurately discriminated early-stage, LT eligible patients (median, 0 CTCs) from locally advanced/metastatic, LT ineligible patients (median, 6 CTCs; AUROC = 0.89; P = 0.001; sensitivity = 87.1%; specificity = 90.0%), and predicted OS for all patients (hazard ratio [HR], 2.21; P = 0.001), and faster recurrence after curative-intent surgical or locoregional therapy in potentially curable early-stage HCC (HR, 3.14; P = 0.002). In conclusion, we developed a novel multimarker CTC enrichment assay that detects HCC CTCs with high efficiency and accuracy. A phenotypic subpopulation of VIM-positive CTCs appears to signify the presence of aggressive underlying disease and occult metastases and may have important implications for treatment selection. Liver Transplantation 24 946-960 2018 AASLD.

ADAM17 promotes cell migration and invasion through the integrin β1 pathway in hepatocellular carcinoma

ADAM17 is believed to promote tumor development by facilitating both cell proliferation and migration. In this study, we investigated the involvement of ADAM17 and the activation of the integrin pathway in the regulation of the malignant properties of hepatocellular carcinoma cells and tissues. ADAM17 was positively correlated with active integrin β1, which was determined using a human tissue microarray and an N-nitrosodiethylamine-induced HCC mouse model. We found elevated ADAM17 and active integrin β1 levels in HCC tissues compared with adjacent liver tissues, and the active integrin β1 levels were associated with tumor size and TNM grade. High ADAM17 and active integrin β1 levels in tumor tissues were significantly associated with poor survival of HCC patients. RNAi-mediated ADAM17 knockdown and integrin β1 blockade significantly attenuated the migration and invasion of HCC cells, and overexpression of ADAM17 showed the reverse effects. ADAM17 interference attenuated the intrahepatic growth and metastasis of HCC cells in an orthotopic xenograft model. ADAM17-knockdown cells showed diminished levels of active integrin β1, p-FAK, p-AKT, MMP-2 and MMP-9. ADAM17 knockdown significantly attenuated the translocation of the Notch1 intracellular domain into the nucleus, whereas overexpression of the Notch1 intracellular domain rescued the translocation and enhanced the activation of integrin β1. Our data provide evidence for ADAM17 as an important determinant of malignant properties via regulation of integrin β1 activation and Notch1 signaling. Inhibition of ADAM17 may provide viable therapeutic potential for preventing HCC metastasis.

Supervillin promotes epithelial-mesenchymal transition and metastasis of hepatocellular carcinoma in hypoxia via activation of the RhoA/ROCK-ERK/p38 pathway

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world and metastasis is the leading cause of death associated with HCC. Hypoxia triggers the epithelial-mesenchymal transition (EMT) of cancer cells, which enhances their malignant character and elevates metastatic risk. Supervillin associates tightly with the membrane and cytoskeleton, promoting cell motility, invasiveness, and cell survival. However, the roles of supervillin in HCC metastasis remain unclear.

Methods

Tissue microarray technology was used to immunohistochemically stain for supervillin antibody in 173 HCC tissue specimens and expression levels correlated with the clinicopathological variables. Tumor cell motility and invasiveness, as well as changes in the mRNA expression levels of genes associated with cancer cell EMT, were investigated. The relationship between supervillin and Rho GTPases was examined using Co-IP and GST pull-down.

Results

Hypoxia-induced upregulation of supervillin promoted cancer cell migration and invasion via the activation of the ERK/p38 pathway downstream of RhoA/ROCK signaling. Furthermore, supervillin regulated the expression of EMT genes during hypoxia and accelerated the metastasis of HCC in vivo.

Conclusions

Hypoxia-induced increase in supervillin expression is a significant and independent predictor of cancer metastasis, which leads to poor survival in HCC patients. Our results suggest that supervillin may be a candidate prognostic factor for HCC and a valuable target for therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0787-2) contains supplementary material, which is available to authorized users.

Farnesoid X Receptor Activation Enhances Transforming Growth Factor β-Induced Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma Cells

Farnesoid X receptor (FXR) is a receptor for bile acids and plays an important role in the regulation of bile acid metabolism in the liver. Although FXR has been shown to affect hepatocarcinogenesis through both direct and indirect mechanisms, potential roles of FXR in epithelial–mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) remain unclear. We examined the effect of several FXR ligands on EMT-related morphological changes in HCC cell lines, such as HuH-7 and Hep3B cells. FXR agonists (chenodeoxycholic acid, GW4064, and obeticholic acid)—but not an antagonist (guggulsterone)—induced actin polymerization and expression of N-cadherin and phosphorylated focal adhesion kinase, although they were less effective than transforming growth factor β (TGF-β). FXR agonist treatment enhanced TGF-β-induced EMT morphologic changes and FXR antagonist inhibited the effect of TGF-β. Thus, FXR activation enhances EMT in HCC and FXR antagonists may be EMT-suppressing drug candidates.

Expression of Transcription Factor 21 (TCF21) and Upregulation Its Level Inhibits Invasion and Metastasis in Esophageal Squamous Cell Carcinoma

Background

Transcription factor 21 (TCF21), a member of the class A of basic helix-loop-helix family, has been widely identified as a tumor suppressor. Growing evidence has demonstrated the downregulation of TCF21 in distinct cancers. The aim of this study was to explore the expression and biological functions of TCF21 in esophageal squamous cell carcinoma (ESCC).

Material/Methods

TCF21 expression in esophageal cancer cell lines and carcinomas tissues were detected, and its associations with clinical characteristics were analyzed. We carried out this study of biological functions and underlying mechanisms using TE10 and KYSE510 cell lines.

Results

TCF21 mRNA and protein expression were both downregulated in esophageal cancer tissues compared with adjacent normal tissues. Low expression of TCF21 was closely correlated with N stage. In Kaplan-Meier survival analysis, patients with lower TCF21 expression had poorer prognosis. Overexpression of TCF21 greatly inhibited the proliferation, migration, and invasion in both TE10 and KYSE510 cell lines. Furthermore, mechanistic studies showed that with TCF21 gene overexpressed, the expression of tumor suppressor Kiss-1 was upregulated and epithelial-mesenchymal transition (EMT) related proteins (E-cadherin, N-cadherin, Snail, Twist, and Vimentin) which participate in cancer cell invasion and metastasis, were reversed.

Conclusions

TCF21 is downregulated in ESCC, and its low expression is closely correlated with N stage and predicts a poor prognosis. TCF21 functions as a tumor suppressor in ESCC progression, and enhancement of its expression levels may be partly through promoting Kiss-1 expression to reverse EMT by modulating EMT-related gene expression. Thus, TCF21 can potentially be used as a treatment target for ESCC.

Fibrinogen‑like‑protein 1 promotes the invasion and metastasis of gastric cancer and is associated with poor prognosis

The protective role of fibrinogen-like-protein 1 (FGL1) in liver injury has been reported previously. However, there are few studies on FGL1 expression in gastric cancer (GC) tissues, and the role of FGL1 in GC remains unclear. The aim of the present study was to investigate the correlation between FGL1 expression and prognosis in GC patients. Data was downloaded from The Cancer Genome Atlas database, and 50 pairs of GC tissues and the corresponding non-tumor tissues were collected between 2008 to 2011. Furthermore, FGL1 expression was silenced in order to explore its role in SGC-7901 cell proliferation, invasion and migration using Cell Counting Kit-8, wound healing, Transwell invasion and migration assays, respectively. Finally, whether FGL1 is involved in epithelial-mesenchymal transition (EMT) regulation in SGC-7901 cells was determined by western blotting. The results revealed that FGL1 expression was upregulated in GC tissues, and the overall survival time of GC patients with high FGL1 expression levels was markedly shorter than that of GC patients with low FGL1 expression levels (P=0.005). In addition, silencing FGL1 significantly inhibited SGC-7901 cell proliferation, invasion and migration in vitro. Finally, western blot analyses indicated that knockdown of FGL1 markedly increased E-cadherin expression levels (P<0.01), and significantly decreased N-cadherin (P<0.01) and vimentin expression levels (P<0.01), thereby suggesting that FGL1 may promote EMT. These results indicated that FGL1 has the potential to be a predictor in GC patients as well as a target for the treatment of GC.

Isoviolanthin Extracted from Dendrobium officinale Reverses TGF-β1-Mediated Epithelial⁻Mesenchymal Transition in Hepatocellular Carcinoma Cells via Deactivating the TGF-β/Smad and PI3K/Akt/mTOR Signaling Pathways

Dendrobium officinale is a precious medicinal herb and health food, and its pharmacological actions have been studied and proved. However, the mechanisms by which its active flavonoid glycosides affect epithelial⁻mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) cells, such as HepG2 and Bel-7402 cells, have not been previously investigated. Therefore, we investigated whether isoviolanthin extracted from the leaves of Dendrobium officinale inhibits transforming growth factor (TGF)-β1-induced EMT in HCC cells. In this study, the physicochemical properties and structure of isoviolanthin were identified by HPLC, UV, ESIMS, and NMR and were compared with literature data. HCC cells were pretreated with 10 ng/mL TGF-β1 to induce EMT and then treated with isoviolanthin. Herein, we found that isoviolanthin exhibited no cytotoxic effects on normal liver LO2 cells but notably reduced the migratory and invasive capacities of TGF-β1-treated HCC cells. Additionally, isoviolanthin treatment decreased matrix metalloproteinase (MMP)-2 and -9 levels, and remarkably altered the expression of EMT markers via regulating the TGF-β/Smad and PI3K/Akt/mTOR signaling pathways; Western blot analysis confirmed that the effects of the inhibitors SB431542 and LY294002 were consistent with those of isoviolanthin. These findings demonstrate the potential of isoviolanthin as a therapeutic agent for the treatment of advanced-stage metastatic HCC.

circSMAD2 inhibits the epithelial-mesenchymal transition by targeting miR-629 in hepatocellular carcinoma

Background

Circular RNAs (circRNAs) are a class of widely distributed non-coding RNAs, which drew little attention for decades. Recent studies show that circRNAs are involved in cancer progression.

Methods

The circSMAD2 expression in HCC and adjacent non-tumor tissues was measured by quantitative real-time polymerase chain reaction, and the biological function of circSMAD2 was explored by proliferation, apoptosis, migration, invasion, and Western blot assays. Next, the dual-luciferase reporter assay was performed to identify the target miRNA of circSMAD2. Finally, circSMAD2 and its target miRNA were co-transfected in HCC cells to investigate their relationship to HCC progression.

Results

In this study, we found that circRNA SMAD2 (circSMAD2) expression was downregulated in hepatocellular carcinoma (HCC) tissues (P = 0.014) compared to the adjacent non-tumor tissues and markedly associated with the differentiation degree of the HCC tissues (P < 0.001). The in vitro experiments showed that overexpressed circSMAD2 inhibited the migration, invasion, and epithelial–mesenchymal transition (EMT) in HCC cells. Bioinformatics predicted that miR-629 is a potential target of circSMAD2, and the dual-luciferase reporter assay verified that miR-629 directly bound circSMAD2. In addition, we found that overexpression of circSMAD2 suppressed the expression of miR-629 in HCC cells, whereas knockdown of circSMAD2 upregulated the expression of miR-629. Furthermore, co-transfection of miR-629 mimics with circSMAD2 reversed the circSMAD2 effects of inhibiting the migration, invasion, and EMT of HCC cells.

Conclusion

Altogether, our data support that circSMAD2 inhibits the migration, invasion, and EMT of HCC cells by targeting miR-629.

MicroRNA-125a-5p enhances the sensitivity of esophageal squamous cell carcinoma cells to cisplatin by suppressing the activation of the STAT3 signaling pathway

Increasing evidence has demonstrated that microRNAs (miRNAs or miRs) play a variety of roles in tumor development, progression and chemosensitivity in a wide range of tumors. In this study, we found that miR-125a-5p exhibited a low expression in esophageal squamous cell carcinoma (ESCC) tissues and cells, and that its low expression was associated with higher tumor staging and shorter a survival time of patients with ESCC. Moreover, miR-125a-5p overexpression contributed to the suppression of cell proliferation, cell cycle arrest, cell apoptosis and a decrease in cell migratory and invasive abilities, whereas the downregulation of miR-125a-5p promoted cell proliferation, accelerated cell cycle progression, suppressed apoptosis and enhanced the migratory and invasive abilities of ESCC EC1 and TE1 cells, which may be tightly associated with the epithelial-mesenchymal transition (EMT) process in ESCC. Importantly, miR-125a-5p enhanced the cytotoxic effects of cisplatin on EC1 and TE1 cells, and co-treatment with miR-125a-5p and cisplatin significantly induced cell apoptosis and reduced the cell migratory and invasive abilities of EC1 and TE1 cells, coupled with an increase in the E-cadherin level and a decrease in the N-cadherin and Vimentin levels. Most notably, signal transducer and activator of transcription-3 (STAT3) was found to be a direct target of miR-125a-5p in ESCC cells, and miR-125a-5p overexpression significantly reduced the protein levels of t-STAT3, p-STAT3 and vascular endothelial growth factor (VEGF) in EC1 and TE1 cells. Furthermore, the combination of miR-125a-5p and cisplatin markedly inactivated the STAT3 signaling pathway; however, interleukin (IL)-6, a widely reported activator of the STAT3 signaling pathway, reversed the suppressive effects of miR-125a-5p/cisplatin in ESCC cells on the activation of the STAT3 signaling pathway. Of note, we found that IL-6 markedly reversed the altered cell phenotype mediated by the combination of miR-125a-5p and cisplatin in ESCC cells. These findings suggest that miR-125a-5p may play a pivotal role in the development and progression of ESCC, which may be achieved via the manipulation of the STAT3 signaling pathway.

MicroRNA-219-5p Promotes Tumor Growth and Metastasis of Hepatocellular Carcinoma by Regulating Cadherin 1

MicroRNAs play significant roles in the development of cancer and may serve as promising therapeutic targets. In our previous work, miR-219-5p was identified as one of the important metastasis-related microRNAs in HCC. Here we demonstrated that miR-219-5p expression was elevated in HCC tissues and was associated with vascular invasion and dismal prognosis. In multivariate analysis, miR-219-5p was identified as an independent prognostic indicator for HCC patients. Functional mechanism analyses showed that miR-219-5p promoted HCC cell proliferation and invasion in in vitro, as well as in vivo, tumor growth and metastasis in nude mice models bearing human HCC tumors. In addition, cadherin 1 (CDH1) was revealed to be a downstream target of miR-219-5p in HCC cells. In conclusion, miR-219-5p promotes tumor growth and metastasis of HCC by regulating CDH1 and can serve as a prognostic marker for HCC patients.

miR-300 regulates the epithelial-mesenchymal transition and invasion of hepatocellular carcinoma by targeting the FAK/PI3K/AKT signaling pathway

Several microRNAs (miRNAs) have been closely correlated with the development of hepatocellular carcinoma (HCC). However, the involvement of miR-300 in the development of HCC remains unknown. This study elucidated the potential molecular mechanisms of miR-300 in the modulation of the epithelial-mesenchymal transition (EMT) and invasion of HCC. The expression levels of miR-300 in HCC cells and clinical samples were detected by quantitative real-time PCR and in situ hybridization. The in vitro function of miR-300 in HCC was evaluated using a migration/invasion assay. Quantitative real-time PCR, western blotting, immunofluorescence and immunohistochemistry were used to validate the roles of miR-300 and FAK/PI3K/AKT in EMT progression. A dual-luciferase reporter assay was performed to confirm the target gene. miR-300 was down-regulated in HCC and significantly correlated with a poor prognosis in HCC patients. The down-regulation of miR-300 increased the invasiveness of the HCC cells, and promoted the EMT in both HCC tissues and HCC cells. In contrast, up-regulation of miR-300 led to the opposite results. Ectopic overexpression of miR-300 reversed TGF-β1-induced EMT in SMMC-7721 cells, and according to a dual-luciferase reporter assay and rescue assay, miR-300 inhibits the EMT-mediated migration and invasion of HCC cells via the targeted modulation of FAK and the downstream PI3K/AKT signaling pathway. miR-300 targeting modulates FAK, and the PI3K/AKT signaling pathway inhibits the EMT and suppresses the migration and invasion of HCC cells. Thus, miR-300 represents a promising therapeutic target for HCC.

HCC-derived exosomes elicit HCC progression and recurrence by epithelial-mesenchymal transition through MAPK/ERK signalling pathway

Liver cancer is the second most common cause of cancer-related death worldwide. Approximately 70-90% of primary liver cancers are hepatocellular carcinoma (HCC). Currently, HCC patient prognosis is unsatisfactory due to high metastasis and/or post-surgical recurrence rates. Therefore, new therapeutic methods for inhibiting metastasis and recurrence are urgently needed. Exosomes are small lipid-bilayer vesicles that are implicated in tumour development and metastasis. Rab27a, a small GTPase, regulates exosome secretion by mediating multivesicular endosome docking at the plasma membrane. However, whether Rab27a participates in HCC cell-derived exosome exocytosis is unclear. Epithelial-mesenchymal transition (EMT) frequently initiates metastasis. The role of HCC cell-derived exosomes in EMT remains unknown. We found that exosomes from highly metastatic MHCC97H cells could communicate with low metastatic HCC cells, increasing their migration, chemotaxis and invasion. Rab27a knockdown inhibited MHCC97H-derived exosome secretion, which consequently promoted migration, chemotaxis and invasion in parental MHCC97H cells. Mechanistic studies showed that the biological alterations in HCC cells treated with MHCC97H-derived exosomes or MHCC97H cells with reduced self-derived exosome secretion were caused by inducing EMT via MAPK/ERK signalling. Animal experiments indicated that exosome secretion blockade was associated with enhanced lung and intrahepatic metastasis of parental MHCC97H cells, while ectopic overexpression of Rab27a in MHCC97H cells could rescue this enhancement of metastasis in vivo. Injection of MHCC97H cell-derived exosomes through the tail vein promoted intrahepatic recurrence of HLE tumours in vivo. Clinically, Rab27a was positively associated with serum alpha-fetoprotein (AFP) level, vascular invasion and liver cirrhosis. Our study elucidated the role of exosomes in HCC metastasis and recurrence, suggesting that they are promising therapeutic and prognostic targets for HCC patients.

IL-17A promotes the invasion-metastasis cascade via the AKT pathway in hepatocellular carcinoma

We previously demonstrated that interleukin‐17A (IL‐17A) is associated with the progression of hepatocellular carcinoma (HCC). However, its role in the invasion–metastasis cascade of HCC and the efficacy of IL‐17A‐targeting therapeutics in HCC remain largely unknown. In this study, we found that IL‐17A promoted intrahepatic and pulmonary metastasesis of HCC cells in an orthotopic implant model. Moreover, our results showed that IL‐17A induced epithelial–mesenchymal transition (EMT) and promoted HCC cell colonization in vitro and in vivo, and the role of IL‐17A in invasion–metastasis was dependent on activation of the AKT pathway. Remarkably, combined therapy using both secukinumab and sorafenib has better inhibition on tumour growth and metastasis compared to sorafenib monotherapy. Additionally, the combination of intratumoral IL‐17A+ cells and E‐cadherin predicted the outcome of patients with HCC at an early stage after hepatectomy based on tissue microarray and immunohistochemistry. In conclusion, our studies reveal that IL‐17A induces early EMT and promotes late colonization of HCC metastasis by activating AKT signalling. Secukinumab is a promising candidate for clinical development in combination with sorafenib for the management of HCC.

Hepatitis C Virus-Associated Cancers

Most hepatitis C virus (HCV) infection results in persistent infection. Significant portion of chronic HCV-infected patients develop hepatocellular carcinoma (HCC). Chronic hepatitis C is also associated with extrahepatic manifestations, including cryoglobulinemia, lymphoma, insulin resistance, type 2 diabetes, and neurological disorders. The molecular mechanisms of how HCV infection causes liver cancer are largely unknown. HCV replication or viral proteins may perturb cellular hemostasis and induce the generation of reactive oxygen species (ROS); viral components or viral replication products act as agonist to trigger innate immune response and cause chronic inflammation. Within the liver, non-hepatocytes such as hepatic stellate cell (HSC) are activated upon HCV infection to provide the major source of extracellular proteins and play important roles in fibrogenesis. With the great achievements of HCV treatment, especially the direct-acting antivirals (DAAs) against HCV, HCV eradication is possible. However, until now there are only very limited data on the effect of DAA-based anti-HCV treatment on HCC patients.

BMP signaling and its paradoxical effects in tumorigenesis and dissemination

Bone morphogenetic proteins (BMPs) play important roles in embryonic and postnatal development by regulating cell differentiation, proliferation, motility, and survival, thus maintaining homeostasis during organ and tissue development. BMPs can lead to tumorigenesis and regulate cancer progression in different stages. Therefore, we summarized studies on BMP expression, the clinical significance of BMP dysfunction in various cancer types, and the molecular regulation of various BMP-related signaling pathways. We emphasized on the paradoxical effects of BMPs on various aspects of carcinogenesis, including epithelial–mesenchymal transition (EMT), cancer stem cells (CSCs), and angiogenesis. We also reviewed the molecular mechanisms by which BMPs regulate tumor generation and progression as well as potential therapeutic targets against BMPs that might be valuable in preventing tumor growth and invasion.

Galunisertib suppresses the staminal phenotype in hepatocellular carcinoma by modulating CD44 expression

Cancer stem cells (CSCs) niche in the tumor microenvironment is responsible for cancer recurrence and therapy failure. To better understand its molecular and biological involvement in hepatocellular carcinoma (HCC) progression, one can design more effective therapies and tailored then to individual patients. While sorafenib is currently the only approved drug for first-line treatment of advanced stage HCC, its role in modulating the CSC niche is estimated to be small. By contrast, transforming growth factor (TGF)-β pathway seems to influence the CSC and thus may impact hallmarks of HCC, such as liver fibrosis, cirrhosis, and tumor progression. Therefore, blocking this pathway may offer an appealing and druggable target. In our study, we have used galunisertib (LY2157299), a selective ATP-mimetic inhibitor of TGF-β receptor I (TGFβI/ALK5) activation, currently under clinical investigation in HCC patients. Because the drug resistance is mainly mediated by CSCs, we tested the effects of galunisertib on stemness phenotype in HCC cells to determine whether TGF-β signaling modulates CSC niche and drug resistance. Galunisertib modulated the expression of stemness-related genes only in the invasive (HLE and HLF) HCC cells inducing a decreased expression of CD44 and THY1. Furthermore, galunisertib also reduced the stemness-related functions of invasive HCC cells decreasing the formation of colonies, liver spheroids and invasive growth ability. Interestingly, CD44 loss of function mimicked the galunisertib effects on HCC stemness-related functions. Galunisertib treatment also reduced the expression of stemness-related genes in ex vivo human HCC specimens. Our observations are the first evidence that galunisertib effectiveness overcomes stemness-derived aggressiveness via decreased expression CD44 and THY1.

Down-regulation of salt-inducible kinase 1 (SIK1) is mediated by RNF2 in hepatocarcinogenesis

Our previous study reported that down-regulation of SIK1 accelerates the growth and invasion of hepatocellular carcinoma (HCC). However, the underlying mechanism leading to SIK1 down-regulation in HCC largely remains to be determined. Herein, we demonstrated that RNF2 expression is negatively correlated with SIK1 levels in HCC tissues. Kaplan-Meier analysis of tumor samples revealed that high RNF2 expression with concurrent low SIK1 expression is associated with poor overall survival. The down-regulation of RNF2 expression in HCC cells significantly reduces tumor cell growth and metastasis, while the simultaneous down-regulation of both RNF2 and SIK1 restores tumor cell growth in vitro and in tumor xenograft models. Mechanistically, we identified RNF2 as an E3 ligase that targets SIK1 for degradation. We further demonstrated that direct physical interaction between RNF2 and SIK1 triggers SIK1 down-regulation in HCC cells. These data suggest that RNF2 is an important upstream negative regulator of SIK1 and that restoration of SIK1 levels induced by loss of RNF2 inhibited HCC cell growth and promoted apoptosis, which may represent a promising therapeutic strategy for HCC treatment.

The NCX1/TRPC6 Complex Mediates TGFβ-Driven Migration and Invasion of Human Hepatocellular Carcinoma Cells

TGFβ plays an important role in the progression and metastasis of hepatocellular carcinoma (HCC), yet the cellular and molecular mechanisms underlying this role are not completely understood. In this study, we investigated the roles of Na⁺/Ca²⁺ exchanger 1 (NCX1) and canonical transient receptor potential channel 6 (TRPC6) in regulating TGFβ in human HCC. In HepG2 and Huh7 cells, TGFβ-stimulated intracellular Ca²⁺ increases through NCX1 and TRPC6 and induced the formation of a TRPC6/NCX1 molecular complex. This complex-mediated Ca²⁺ signaling regulated the effect of TGFβ on the migration, invasion, and intrahepatic metastasis of human HCC cells in nude mice. TGFβ upregulated TRPC6 and NCX1 expression, and there was a positive feedback between TRPC6/NCX1 signaling and Smad signaling. Expression of both TRPC6 and NCX1 were markedly increased in native human HCC tissues, and their expression levels positively correlated with advancement of HCC in patients. These data reveal the role of the TRPC6/NCX1 molecular complex in HCC and in regulating TGFβ signaling, and they implicate TRPC6 and NCX1 as potential targets for therapy in HCC.Significance: TGFβ induces the formation and activation of a TRPC6/NCX1 molecular complex, which mediates the effects of TGFβ on the migration, invasion, and intrahepatic metastasis of HCC. Cancer Res; 78(10); 2564-76. ©2018 AACR.

ADAM9 mediates the interleukin-6-induced Epithelial-Mesenchymal transition and metastasis through ROS production in hepatoma cells

Interleukin (IL)-6 has been implicated in the invasion and metastasis of hepatocellular carcinoma (HCC). However, the molecular events that mediate this process are poorly understood. Here, we showed that IL-6 promoted the epithelial-mesenchymal transition (EMT) in HCC cell lines, and upregulated a disintegrin and metalloprotease 9 (ADAM9) expression by activating the JNK signaling pathway. ADAM9 was upregulated in human HCCs which promoted HCC cell invasion and the EMT by interacting with NADPH oxidase 1 and inducing reactive oxygen species generation. Knockdown of ADAM9 inhibited the IL-6-induced EMT. Additionally, ADAM9 expression was positively correlated with IL-6 and Snail expression in human HCC specimens. Taken together, our results showed that ADAM9 is an important mediator of IL-6-induced HCC cell migration and invasion, and may provide a novel therapeutic target for HCC management.

Copper/MYC/CTR1 interplay: a dangerous relationship in hepatocellular carcinoma

Free serum copper correlates with tumor incidence and progression of human cancers, including hepatocellular carcinoma (HCC). Copper extracellular uptake is provided by the transporter CTR1, whose expression is regulated to avoid excessive intracellular copper entry. Inadequate copper serum concentration is involved in the pathogenesis of Non Alcoholic Fatty Liver Disease (NAFLD), which is becoming a major cause of liver damage progression and HCC incidence. Finally, MYC is over-expressed in most of HCCs and is a critical regulator of cellular growth, tumor invasion and metastasis.

The purpose of our study was to understand if higher serum copper concentrations might be involved in the progression of NAFLD-cirrhosis toward-HCC. We investigated whether high exogenous copper levels sensitize liver cells to transformation and if it exists an interplay between copper-related proteins and MYC oncogene.

NAFLD-cirrhotic patients were characterized by a statistical significant enhancement of serum copper levels, even more evident in HCC patients. We demonstrated that high extracellular copper concentrations increase cell growth, migration, and invasion of liver cancer cells by modulating MYC/CTR1 axis. We highlighted that MYC binds a specific region of the CTR1 promoter, regulating its transcription. Accordingly, CTR1 and MYC proteins expression were progressively up-regulated in liver tissues from NAFLD-cirrhotic to HCC patients.

This work provides novel insights on the molecular mechanisms by which copper may favor the progression from cirrhosis to cancer. The Cu/MYC/CTR1 interplay opens a window to refine HCC diagnosis and design new combined therapies.

I131 reinforces antitumor activity of metuximab by reversing epithelial-mesenchymal transition via VEGFR-2 signaling in hepatocellular carcinoma

CD147 is highly expressed in hepatocellular carcinoma (HCC) and associated with the invasion and metastasis of HCC. The efficacy of I¹³¹ -metuximab (I¹³¹ -mab), a newly developed agent that targets CD147, as a radio-immunotherapy for local HCC, has been validated in clinical practice. However, the synergistic anticancer activity and molecular mechanism of different conjugated components within I¹³¹ -mab remain unclear. In this study, the cytological experiments proved that I¹³¹ -mab inhibited the proliferation and invasion of HCC cells. Mechanically, this inhibition effect was mainly mediated by the antibody component part of I¹³¹ -mab, which could reverse the epithelial-mesenchymal transition of HCC cells partially by suppressing the phosphorylation of VEGFR-2. The inhibitory effect of I¹³¹ on HCC cell proliferation and invasion is limited, whereas, when combined with metuximab, I¹³¹ significantly enhanced the sensitivity of HCC cells to CD147-mab and consequently reinforced the anticancer effects of CD147-mab, suggesting that the two components of I¹³¹ -mab exerted synergistic anti-HCC capability. Furthermore, the experiments using SMMC-7721 human HCC xenografts in athymic nude mice showed that I¹³¹ -mab and CD147-mab significantly inhibited the growth of xenograft tumors and that I¹³¹ -mab was more effective than CD147-mab. In conclusion, our results elucidated the mechanism underlying the anti-HCC effects of I¹³¹ -mab and provided a theoretical foundation for the clinical application of I¹³¹ -mab.

Overexpression of NEDD9 promotes cell invasion and metastasis in hepatocellular carcinoma

Neural precursor cell expressed, developmentally downregulated 9 (NEDD9), is a focal adhesion scaffold protein which has been associated with metastasis in several cancers. Recent study found that NEDD9 expression was upregulated in HCC. However, the precise function of NEDD9 in HCC is still unclear. In the present study, we demonstrated that high NEDD9 expression was associated with the invasiveness of HCC in clinical samples. Moreover, by gain-and-loss function studies, we revealed that silencing of NEDD9 expression inhibited cancer cells proliferation, migration and invasion, while upregulated expression of NEDD9 promoted invasion and metastasis of HCC cells in vitro and in vivo. Further studies revealed that NEDD9 inversely regulated E-cadherin in HCC cells and HCC tissues, which indicated that NEDD9 might promotes the invasion and metastasis of HCC cells through the downregulation of E-cadherin, possibly by inducing EMT. On the whole, our findings thus indicate that NEDD9 may serve as a metastasis-promoting gene and potential therapeutic target for the treatment of hepatocellular carcinoma.

A small population of liver endothelial cells undergoes endothelial-to-mesenchymal transition in response to chronic liver injury

Rising evidence points to endothelial-to-mesenchymal transition (EndMT) as a significant source of the mesenchymal cell population in fibrotic diseases. In this context, we hypothesized that liver endothelial cells undergo EndMT during fibrosis progression. Cirrhosis in mice was induced by CCl₄ A transgenic mouse expressing a red fluorescent protein reporter under the control of Tie2 promoter (Tie2-tdTomato) was used to trace the acquisition of EndMT. Sinusoidal vascular connectivity was evaluated by intravital microscopy and high-resolution three-dimensional confocal microscopy. A modest but significant fraction of liver endothelial cells from both cirrhotic patients and CCl₄-treated Tie2-tdTomato mice acquired an EndMT phenotype characterized by the coexpression of CD31 and α-smooth muscle actin, compared with noncirrhotic livers. Bone morphogenetic protein-7 (BMP-7) inhibited the acquisition of EndMT induced by transforming growth factor-β1 (TGF-β1) treatment in cultured primary mouse liver endothelial cells from control mice. EndMT was also reduced significantly in vivo in cirrhotic Tie2-tdTomato mice treated intraperitoneally with BMP-7 compared with untreated mice (1.9 ± 0.2 vs. 3.8 ± 0.3%, respectively; P < 0.05). The decrease of EndMT in cirrhotic livers correlated with a significant decrease in liver fibrosis (P < 0.05) and an improvement in the vascular disorganization rate (P < 0.05). We demonstrated the acquisition of the EndMT phenotype by a subpopulation of endothelial cells from cirrhotic livers in both animal models and patients. BMP-7 treatment decreases the occurrence of the EndMT phenotype and has a positive impact on the severity of disease by reducing fibrosis and sinusoidal vascular disorganization.NEW & NOTEWORTHY A subpopulation of liver endothelial cells from cirrhotic patients and mice with liver fibrosis undergoes endothelial-to-mesenchymal transition. Liver endothelial cells from healthy mice could transition into a mesenchymal phenotype in culture in response to TGF-β1 treatment. Fibrotic livers treated chronically with BMP-7 showed lower EndMT acquisition, reduced fibrosis, and improved vascular organization.

Transforming Growth Factor-β Drives the Transendothelial Migration of Hepatocellular Carcinoma Cells

The entry of malignant hepatocytes into blood vessels is a key step in the dissemination and metastasis of hepatocellular carcinoma (HCC). The identification of molecular mechanisms involved in the transmigration of malignant hepatocytes through the endothelial barrier is of high relevance for therapeutic intervention and metastasis prevention. In this study, we employed a model of hepatocellular transmigration that mimics vascular invasion using hepatic sinusoidal endothelial cells and malignant hepatocytes evincing a mesenchymal-like, invasive phenotype by transforming growth factor (TGF)-β. Labelling of respective cell populations with various stable isotopes and subsequent mass spectrometry analyses allowed the “real-time” detection of molecular changes in both transmigrating hepatocytes and endothelial cells. Interestingly, the proteome profiling revealed 36 and 559 regulated proteins in hepatocytes and endothelial cells, respectively, indicating significant changes during active transmigration that mostly depends on cell–cell interaction rather than on TGF-β alone. Importantly, matching these in vitro findings with HCC patient data revealed a panel of common molecular alterations including peroxiredoxin-3, epoxide hydrolase, transgelin-2 and collectin 12 that are clinically relevant for the patient’s survival. We conclude that hepatocellular plasticity induced by TGF-β is crucially involved in blood vessel invasion of HCC cells.

Dihydroartemisinin inhibits EMT induced by platinum-based drugs via Akt-Snail pathway

Artemisinin and its derivatives exhibit a high activity against a range of cancer cell types both in vitro and in vivo. In clinical practice, platinum-based anti-cancer chemotherapy is widely used to treat tumors. However, a large proportion of patients receiving these treatments will relapse because of metastasis and drug resistance. The purpose of this study is to explore the combinational anti-metastatic effect of platinum-based drugs and dihydroartemisinin (DHA). Both DDP and oxaliplatin (OXA) at low doses could induce epithelial–mesenchymal transition (EMT) in HCC. Meanwhile, co-administration of DHA could enhance DDP and OXA chemosensitivity in HCC and reverse drug resistance. DHA reversed the morphological changes induced by DDP or OXA and reversed the changes in EMT biomarkers induced by DDP and OXA in HCC in vitro and in vivo via AKT–Snail signaling. DHA significantly increased platinum-based drug sensitivity and suppressed EMT induced by platinum-based drugs via AKT–Snail signaling in HCC. DHA is expected to become the new adjuvant for chemotherapy.

Attenuation of MET-mediated migration and invasion in hepatocellular carcinoma cells by SOCS1

AIM

To investigate the role of suppressor of cytokine signaling 1 (SOCS1) in regulating MET-mediated invasive potential of hepatocellular carcinoma (HCC) cells.

METHODS

Stable derivatives of mouse (Hepa1-6) and human (hep3B, HepG2) HCC cell lines expressing SOCS1 or control vector were evaluated for their ability to migrate towards hepatocyte growth factor (HGF) in the transwell migration assay, invade extracellular matrix in response to HGF stimulation in a 3-D invasion assay by confocal microscopy, and to undergo anchorage-independent proliferation in semisolid agar. Following intravenous and intrasplenic inoculation into NOD.scid.gamma mice, the ability of Hepa cells to form othotopic tumors was evaluated. Following HGF stimulation of Hepa and Hep3B cells, expression of proteins implicated in epithelial-to-mesenchymal transition was evaluated by western blot and qRT-PCR.

RESULTS

SOCS1 expression in mouse and human HCC cells inhibited HGF-induced migration through matrigel. In the 3-D invasion assay, HGF stimulation induced invasion of HCC cells across type-I collagen matrix, and SOCS1 expression significantly reduced the depth of invasion. SOCS1 expression also reduced the number and size of colonies formed by anchorage-independent growth in semisolid agar. Following intravenous inoculation, control Hepa cell formed large tumor nodules that obliterated the liver whereas the SOCS1-expressing Hepa cells formed significantly smaller nodules. Tumors formed by SOCS1-expressing cells showed reduced phosphorylation of STAT3 and ERK that was accompanied by reduced levels of MET protein expression. HGF stimulated Hepa cells expressing SOCS1 showed increased expression of E-cadherin and decreased expression of EGR1, SNAI1 and ZEB1. Comparable results were obtained with Hep3B cells. SOCS1 expressing HCC cells also showed reduced levels of EGR1 and SNAI1 transcripts.

CONCLUSION

Our findings indicate that loss of SOCS1-dependent control over epithelial-to-mesenchymal transition may contribute to MET-mediated migration, invasion and metastatic growth of HCC.

LDHA promotes tumor metastasis by facilitating epithelial‑mesenchymal transition in renal cell carcinoma

Previous studies have indicated that high expression of lactate dehydrogenase A (LDHA) exists in many human cancers. Recently, several reports showed that silencing or inhibition of LDHA could suppress metastasis of human cancer including renal cell carcinoma (RCC). However, the mechanism remains unknown. The role of LDHA in RCC migration and invasion was investigated using immunohistochemistry, western blotting, Transwell and scratch assays, and in vivo experiment. The influence of LDHA on the Warburg effect was also investigated by LDHA activity and lactate production assay. LDHA was overexpressed in RCC tissues and predicted a worse survival following renal resection. Correlation analysis demonstrated that LDHA was negatively correlated with E‑cadherin and positively with N‑cadherin. Experimentally, both in vivo and in vitro experiments found downregulation of LDHA suppressed RCC cells migration and invasion by inhibiting EMT. In addition, results indicated LDHA could promote the Warburg effect. Further research presented that the LDHA inhibitor, oxamate, suppressed tumor metastasis by inhibiting LDHA activity and EMT. These results demonstrated that LDHA mediates tumor metastasis by promoting EMT in RCC, suggesting that LDHA could be a promising therapeutic target for RCC therapy.

A novel three-dimensional culture system maintaining the physiological extracellular matrix of fibrotic model livers accelerates progression of hepatocellular carcinoma cells

Liver fibrosis is characterized by the progressive accumulation of extracellular matrix (ECM) and is a strong predictor of hepatocellular carcinoma (HCC) development and progression. However, the effect of ECM in fibrotic livers on HCC cells is poorly understood. The aims of this study were to create a new culture system that retained the natural ECM of fibrotic model livers and to establish whether natural ECM regulated the characteristics of HCC cells. Using an organ decellularization technique, we created a new culture system that preserved the tissue-specific ECM of fibrotic model livers from CCl₄-treated rats. The content of ECM in fibrotic model liver scaffolds was increased and the ECM microstructure was distorted. Quantitative polymerase chain reaction and immunofluorescence assays of HCC cells cultured in fibrotic model liver scaffolds for 7 days showed an epithelial-mesenchymal transition phenotype. Moreover, the ECM of fibrotic model livers promoted proliferation and chemoresistance of HCC cells. These results showed a novel effect of natural ECM in fibrotic model livers on the malignant behaviour of HCC cells. This new culture system will be useful for both understanding the cell biology of fibrotic livers and developing novel anti-cancer drugs.