Phenotype Of Hepatocellular Carcinoma Research Articles

Reciprocal activating crosstalk between c-Met and caveolin 1 promotes invasive phenotype in hepatocellular carcinoma.

c-Met, the receptor for Hepatocyte Growth Factor (HGF), overexpressed and deregulated in Hepatocellular Carcinoma (HCC). Caveolin 1 (CAV1), a plasma membrane protein that modulates signal transduction molecules, is also overexpressed in HCC. The aim of this study was to investigate biological and clinical significance of co-expression and activation of c-Met and CAV1 in HCC. We showed that c-Met and CAV1 were co-localized in HCC cells and HGF treatment increased this association. HGF-triggered c-Met activation caused a concurrent rise in both phosphorylation and expression of CAV1. Ectopic expression of CAV1 accelerated c-Met signaling, resulted in enhanced migration, invasion, and branching-morphogenesis. Silencing of CAV1 downregulated c-Met signaling, and decreased migratory/invasive capability of cells and attenuated branching morphogenesis. In addition, activation and co-localization of c-Met and CAV1 were elevated during hepatocarcinogenesis. In conclusion reciprocal activating crosstalk between c-Met and CAV1 promoted oncogenic signaling of c-Met contributed to the initiation and progression of HCC.

The genomic landscape of hepatoblastoma and their progenies with HCC-like features

Hepatoblastoma (HB) is the most common childhood liver cancer and occasionally presents with histological and clinical features reminiscent of hepatocellular carcinoma (HCC). Identification of molecular mechanisms that drive the neoplastic continuation towards more aggressive HCC phenotypes may help to guide the new stage of targeted therapies. We performed comprehensive studies on genetic and chromosomal alterations as well as candidate gene function and their clinical relevance. Whole-exome sequencing identified HB as a genetically very simple tumour (2.9 mutations per tumour) with recurrent mutations in ß-catenin (CTNNB1) (12/15 cases) and the transcription factor NFE2L2 (2/15 cases). Their HCC-like progenies share the common CTNNB1 mutation, but additionally exhibit a significantly increased mutation number and chromosomal instability due to deletions of the genome guardians RAD17 and TP53, accompanied by telomerase reverse-transcriptase (TERT) promoter mutations. Targeted genotyping of 33 primary tumours and cell lines revealed CTNNB1, NFE2L2, and TERT mutations in 72.5%, 9.8%, and 5.9% of cases, respectively. All NFE2L2 mutations affected residues of the NFE2L2 protein that are recognized by the KEAP1/CUL3 complex for proteasomal degradation. Consequently, cells transfected with mutant NFE2L2 were insensitive to KEAP1-mediated downregulation of NFE2L2 signalling. Clinically, overexpression of the NFE2L2 target gene NQO1 in tumours was significantly associated with metastasis, vascular invasion, the adverse prognostic C2 gene signature, as well as poor outcome. Our study demonstrates the importance of CTNNB1 mutations and NFE2L2-KEAP1 pathway activation in HB development and defines loss of genomic stability and TERT promoter mutations as prominent characteristics of aggressive HB with HCC features.

HOXB9 promotes epithelial-to-mesenchymal transition via transforming growth factor-β1 pathway in hepatocellular carcinoma cells.

The function of the epithelial-to-mesenchymal transition (EMT) during hepatocellular carcinoma (HCC) progression is well established. However, the regulatory mechanisms modulating this phenomenon remain unclear. Homeobox B9 (HOXB9) has been proposed as an oncogene in many cancer developments, but its function and underlying mechanisms in HCC metastasis remain unknown. HOXB9 modulates EMT through the transforming growth factor-β1 (TGF-β1) pathway, which is a recognized regulator of EMT in HCC cells. The knockdown of HOXB9 decreased the migration and invasion of HCC cells. Conversely, the HOXB9 overexpression led to an increase in the above-mentioned phenotypes in HCC cells. Further analysis of HOXB9-regulated cellular functions showed the ability of this transcription factor to induce EMT. Moreover, we demonstrated that the TGF-β1 pathway is important in HOXB9-induced EMT in HCC cells. These findings define a novel cellular mechanism regulated by HOXB9, which controls EMT phenotype in HCC. This study is the first to illustrate the pivotal function of HOXB9 in regulating the metastatic behavior of HCC cells.

MicroRNA-122 triggers mesenchymal-epithelial transition and suppresses hepatocellular carcinoma cell motility and invasion by targeting RhoA.

The loss of microRNA-122 (miR-122) expression is strongly associated with increased invasion and metastasis, and poor prognosis of hepatocellular carcinoma (HCC), however, the underlying mechanisms remain poorly understood. In the present study, we observed that miR-122 over-expression in HCC cell lines Sk-hep-1 and Bel-7402 triggered the mesenchymal-epithelial transition (MET), as demonstrated by epithelial-like morphological changes, up-regulated epithelial proteins (E-cadherin, ZO-1, α-catenin, occludin, BVES, and MST4), and down-regulated mesenchymal proteins (vimentin and fibronectin). The over-expression of miRNA-122 also caused cytoskeleton disruption, RhoA/Rock pathway inactivation, enhanced cell adhesion, and suppression of migration and invasion of Sk-hep-1 and Bel-7402 cells, whereas, these effects could be reversed through miR-122 inhibition. Additional studies demonstrated that the inhibition of wild-type RhoA function induced MET and inhibited cell migration and invasion, while RhoA over-expression reversed miR-122-induced MET and inhibition of migration and invasion of HCC cells, suggesting that miR-122 induced MET and suppressed the migration and invasion of HCC cells by targeting RhoA. Moreover, our results demonstrated that HNF4α up-regulated its target gene miR-122 that subsequently induced MET and inhibited cell migration and invasion, whereas miR-122 inhibition reversed these HNF4α-induced phenotypes. These results revealed functional and mechanistic links among the tumor suppressors HNF4α, miR-122, and RhoA in EMT and invasive and metastatic phenotypes of HCC. Taken together, our study provides the first evidence that the HNF4α/miR-122/RhoA axis negatively regulates EMT and the migration and invasion of HCC cells.

Abnormal expression of EMT-related proteins, S100A4, vimentin and E-cadherin, is correlated with clinicopathological features and prognosis in HCC.

We determined the expression of epithelial-mesenchymal transition (EMT) indicator proteins, E-cadherin (E-cad), vimentin (VIM), mucin 1 (MUC1) and S100 calcium-binding protein A4 (S100A4) in hepatocellular carcinoma (HCC) patient tissue samples. We also investigated the relationship between the expression of these proteins and clinicopathologic factors in HCC. Finally, we assessed the potential value of these markers as prognostic indicators of survival in HCC patients. The expression of E-cad, VIM, MUC1 and S100A4 EMT indicator proteins was assessed in tissue microarray HCC tissue sections and corresponding peritumoral normal tissues by immunohistochemistry. In addition, the expression for the four EMT indicator proteins was correlated with clinicopathological features of HCC and patient outcome. Comparison of clinicopathological characteristics and immunohistochemistry by χ(2) analysis revealed that downregulation of E-cad in HCC was significantly associated with later TNM cancer stage (P = 0.012), gross classification (P = 0.018), regional lymph node metastasis (P = 0.036) and liver cirrhosis (P = 0.028). Increased S100A4 expression in HCC was significantly associated with differentiation (P = 0.032), tumor with a complete fibrous capsule (P = 0.031) and portal vein invasion (P = 0.038). High VIM expression in HCC was significantly associated with high serum α-fetoprotein levels (P = 0.016). We also observed that low E-cad expression was significantly associated with overexpression of VIM (P = 0.001). Kaplan-Meier survival and Cox regression analysis revealed that low E-cad expression (HR = 0.164, 95 % CI 0.072 to 0.373, P < 0.001) and high serum α-fetoprotein levels (HR = 2.202, 95 % CI 1.054 to 4.598, P = 0.036) were independent prognostic factors in HCC. Our study demonstrates that high S100A4 and VIM expression and low E-cad expression correlate with an aggressive, malignant phenotype in HCC. These results also support a role for E-cad as a prognostic factor in HCC.

Caveolin-1 Is Up-Regulated by GLI1 and Contributes to GLI1-Driven EMT in Hepatocellular Carcinoma

Caveolin-1 (Cav-1) has been recently identified to be over-expressed in hepatocellular carcinoma (HCC) and promote HCC cell motility and invasion ability via inducing epithelial-mesenchymal transition (EMT). However, the mechanism of aberrant overexpression of Cav-1 remains vague. Here, we observed that Cav-1 expression was positively associated with GLI1 expression in HCC tissues. Forced expression of GLI1 up-regulated Cav-1 in Huh7 cells, while knockdown of GLI1 decreased expression of Cav-1 in SNU449 cells. Additionally, silencing Cav-1 abolished GLI1-induced EMT of Huh7 cells. The correlation between GLI1 and Cav-1 was confirmed in tumor specimens from HCC patients and Cav-1 was found to be associated with poor prognosis after hepatic resection. The relationship between protein expression of GLI1 and Cav-1 was also established in HCC xenografts of nude mice. These results suggest that GLI1 may be attributed to Cav-1 up-regulation which plays an important role in GLI1-driven EMT phenotype in HCC.

Correction: ERManI Is a Target of miR-125b and Promotes Transformation Phenotypes in Hepatocellular Carcinoma (HCC)

Correction: ERManI Is a Target of miR-125b and Promotes Transformation Phenotypes in Hepatocellular Carcinoma (HCC)

Histological Mimicker of Hepatocellular Carcinoma in the Liver

Hepatocellular carcinoma (HCC) is a common malignancy worldwide and the second most common fatal cancer in China and Southeast Asia. Introduction of new treatment modalities including targeted therapy may hopefully bring better survival of patients. A precise pathological diagnosis of HCC is crucial in view of the prognostic and treatment implications. The characteristic histology of HCC can be identified in most cases, yet histological mimickers and poorly differentiated tumors impose diagnostic challenges from time to time. The appropriate use of immunohistochemical markers and cautious interpretation of results are essential in difficult scenarios. Markers such as CD10, polyclonal carcinoembryonic antigen, HepPar-1, and the recently reported arginase 1 are helpful in confirming the hepatocytic differentiation of a malignant liver tumor. Glypican 3, either singly or in combination with glutamine synthetase and heat shock protein 70, is useful in distinguishing HCC from precursor lesions. Immunoexpression of CK19 may signify hepatic progenitor cell phenotype of HCCs. Application of specific immunohistochemical markers for other cell lineages would also help to confirm a diagnosis of liver metastasis. Clinicopathological correlation remains indispensible in pathological diagnosis.

Analysis of chromosomal aberrations in murine HCC.

Liver cancer-also called hepatocellular carcinoma (HCC)-is the most frequent primary liver cancer in humans. As of today, it is mainly induced by chronic virus infections such as Hepatitis B and C viruses, which induce chronic hepatitis and fibrosis, the two most important conditions predisposing towards HCC development. Besides, chronic alcohol or drug consumption contributes to chronic liver injury and HCC development. Of note, in industrialized countries virus infections have recently been outcompeted by a high-fat and high-sugar diet as the most important etiology for HCC development in humans-now representing the fastest growing cancer in the USA as of today. It is believed that soon also in Europe high-fat diet caused HCC will become the fastest growing cancer. Today more than 800,000 people die every year due to cancer; however, despite a great research effort in the last 20 years, no efficient curative therapy is available at the moment. It has turned out that various subtypes of HCC exist in humans, complicating the therapy for HCC patients in general, and leading to the need for therapies of stratified patient cohorts as the variability of HCC phenotypes (6 different subtypes exist as of today) influences the responsiveness to treatment. Thus, it is important to dissect and characterize the various HCC subtypes in humans as well as in mouse models to identify the sub-cohorts that are responsive to particular therapies. One step to do so is the characterization of HCC nodules on genetic level. Here, we describe a protocol to characterize individual HCC nodules on genomic level, enabling to stratify the respective liver carcinoma and select them for a more targeted therapy.

ERManI Is a Target of miR-125b and Promotes Transformation Phenotypes in Hepatocellular Carcinoma (HCC)

The MAN1B1 gene product, designated ER alpha-1, 2-mannosidase (ERManI), is an enzyme localized in the Golgi complex of mammalian cells. By functioning as a “gate keeper” to prevent the inappropriate secretion of misfolded glycoproteins, it plays a critical role in maintaining protein homeostasis in the mammalian secretory pathway. In the present study, we identified that a conserved motif within the 3’UTR of ERManI is a target of miR-125b, a microRNA frequently down-regulated in numerous types of cancers, including hepatocellular carcinoma (HCC). As predicted, the expression of ERManI is significantly elevated in HCC, as measured by immunohistochemistry in a liver spectrum tissue microarray. Additional analyses using several hepatoma cell lines demonstrated that the elevated ERManI inversely correlates with a diminished intracellular concentration of miR-125b. Moreover, functional studies indicated that RNAi-mediated knock-down of endogenous ERManI was sufficient to inhibit proliferation, migration, and invasion of hepatoma cells. These phenotypical changes occurred in the absence of alterations in global glycoprotein secretion or ER-stress status. Together, these results revealed a novel post-transcriptional regulatory mechanism for ERManI and implied that this molecule contributes to the regulation of carcinogenesis in HCC independent of its function in glycoprotein quality control.

Inherent and acquired resistance to paclitaxel in hepatocellular carcinoma: molecular events involved.

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver and is a major cause of cancer related deaths worldwide. Only 10 to 20% of HCC can be surgically excised. Therefore, chemotherapeutic intervention and treatment is essential for achieving favorable prognosis. However, therapeutic outcome of chemotherapy is generally poor owing to inherent resistance of cancer cells to the treatment or due to development of acquired resistance. To differentiate and delineate the molecular events, we developed drug resistant Hep3B cells (DRC) by treating cells with the increasing concentration of paclitaxel. We also developed a unique single cell clone of Hep3B cells (SCC) by selecting single cell colonies and screening them for resistant phenotype. Interestingly, both DRC and SCC were resistant to paclitaxel in comparison to parental Hep3B cells. We analyzed the contributory factors that may be involved in the development of resistance. As expected, level of P-glycoprotein (P-gp) was elevated in DRC. In addition, Caveolin-1 (Cav-1), Fatty acid synthase (FASN) and Cytochrome P450 (CYP450) protein levels were elevated in DRC whereas in SCC, FASN and CYP450 levels were elevated. Downregulation of these molecules by respective siRNAs and/or by specific pharmacological inhibitors resensitized cells to paclitaxel. Interestingly, these drug resistant cells were also less sensitive to vinblastine, doxorubicin and methotrexate with the exception of cisplatin. Our results suggested that differential levels of P-gp, Cav-1 and FASN play a major role in acquired resistant phenotype whereas FASN level was associated with the presentation of inherent resistant phenotype in HCC.

Genomic copy number alterations with transcriptional deregulation at 6p identify an aggressive HCC phenotype

Genomic analyses have revealed the enormous heterogeneity in essentially all cancer types. However, the identification of precise subtypes, which are biologically informative and clinically useful, remains a challenge. The application of integrative analysis of multilayered genomic profiles to define the chromosomal regions of genomic copy number alterations with concomitant transcriptional deregulation is posited to provide a promising strategy to identify driver targets. In this study, we performed an integrative analysis of the DNA copy numbers and gene expression profiles of hepatocellular carcinoma (HCC). By comparing DNA copy numbers between HCC subtypes based on gene expression pattern, we revealed the DNA copy number alteration with concordant gene expression changes at 6p21-p24 particularly in the HCC subtype of aggressive phenotype without expressing stemness genes. Among the genes at 6p21-p24, we identified IER3 as a potential driver. The clinical utility of IER3 copy numbers was demonstrated by validating its clinical correlation with independent cohorts. In addition, short hairpin RNA-mediated knock-down experiment revealed the functional relevance of IER3 in liver cancer progression. In conclusion, our results suggest that genomic copy number alterations with transcriptional deregulation at 6p21-p24 identify an aggressive HCC phenotype and a novel functional biomarker.

Power of metabolomics in diagnosis and biomarker discovery of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the commonest primary hepatic malignancy and the third most common cause of cancer-related death worldwide. Incidence remains highest in the developing world and is steadily increasing across the developed world. Current diagnostic modalities, of ultrasound and α-fetoprotein, are expensive and lack sensitivity in tumor detection. Because of its asymptomatic nature, HCC is usually diagnosed at late and advanced stages, for which there are no effective therapies. Thus, biomarkers for early detection and molecular targets for treating HCC are urgently needed. Emerging high-throughput metabolomics technologies have been widely applied, aiming at the discovery of candidate biomarkers for cancer staging, prediction of recurrence and prognosis, and treatment selection. Metabolic profiles, which are affected by many physiological and pathological processes, may provide further insight into the metabolic consequences of this severe liver disease. Small-molecule metabolites have an important role in biological systems and represent attractive candidates to understand HCC phenotypes. The power of metabolomics allows an unparalleled opportunity to query the molecular mechanisms of HCC. This technique-driven review aims to demystify the metabolomics pathway, while also illustrating the potential of this technique, with recent examples of its application in HCC.

Multivariate Analysis of Prognostic Factors for Survival following Doxorubicin-eluting Bead Transarterial Chemoembolization for Hepatocellular Carcinoma

PurposeTo identify prognostic factors for survival in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization with doxorubicin-eluting beads (DEBs). Materials and MethodsIn a retrospective, single-center analysis, tumor- and patient-related factors were recorded for univariate and multivariate analyses via Kaplan–Meier and Cox regression. Infiltrative HCC phenotype and portal vein invasion (PVI) were correlated, and patients with either or both were classified as having radiographically advanced (RAdv) HCC. The primary endpoint was overall survival, which was calculated from the time of first DEB chemoembolization procedure. ResultsA total of 168 patients underwent 248 procedures, of which 215 (86.7%) were outpatient procedures. Mean length of stay was 0.33 days, and 25 patients (10.1%) were readmitted within 30 days. A total of 33 patients underwent liver transplantation and were excluded from survival analyses. A total of 130 had cirrhosis; 62, 50, and 18 had Child class A, B, and C disease, respectively. Forty-one patients had infiltrative HCC phenotype, 28 of whom also had PVI. Multivariate analysis of survival in all patients showed α-fetoprotein (AFP), performance status (PS), RAdv HCC, Child classification, albumin level, and ascites to predict survival. In patients without RAdv HCC, AFP, PS, Child classification, albumin level, and International Normalized Ratio were independent predictors. Increased bilirubin level was not an independent risk factor for death. ConclusionsIndependent prognostic factors in patients with HCC undergoing DEB chemoembolization have been identified. Increased bilirubin level was not an independent risk factor. These data can be used in HCC patient selection and counseling for DEB chemoembolization.

RhoE is frequently down-regulated in hepatocellular carcinoma (HCC) and suppresses HCC invasion through antagonizing the Rho/Rho-Kinase/Myosin phosphatase target pathway

Deregulation of Rho guanosine triphosphatase (GTPase) pathways plays an important role in tumorigenesis and metastasis of hepatocellular carcinoma (HCC). RhoE/Rnd3 belongs to an atypical subfamily of the RhoGTPase, the Rnd family, as it lacks the intrinsic GTPase activity and remains always in its active GTP-bound form. In this study we investigated the role of RhoE in HCC. We examined the expression of RhoE in primary HCC samples from patients predominantly infected with the hepatitis B virus (HBV) and found that the RhoE messenger RNA (mRNA) level was frequently down-regulated (83.1%, 59/71) in HCCs. Low expression of RhoE in the tumors was significantly associated with shorter disease-free survival (P = 0.020) of the patients. Knockdown of RhoE by short-hairpin RNA using a lentiviral approach led to increased cell motility and invasiveness in SMMC7721 and BEL7402 HCC cells. Moreover, in vivo an orthotopic liver injection model in nude mice further demonstrated that knockdown of RhoE enhanced local invasion of HCC cells in the livers, with more invasive tumor front and increased incidence of venous invasion. Mechanistically, stable knockdown of RhoE in HCC cells significantly enhanced the phosphorylation of myosin phosphatase, promoted assembly of stress fibers, and increased the formation of plasma membrane blebbings, all these changes and activities being associated with activation of the Rho/Rho-kinase (ROCK) pathway. RhoE was frequently down-regulated in predominantly HBV-associated HCCs and this down-regulation was associated with a more aggressive HCC phenotype. RhoE regulated the cytoskeleton remodeling and suppressed HCC motility and invasiveness by way of inhibiting the Rho/ROCK axis.

Reduction of fatty acid oxidation and responses to hypoxia correlate with the progression of de-differentiation in HCC

The prognosis of patients with hepatocellular carcinoma (HCC) may be improved by novel treatments focusing on the characteristic metabolic changes of this disease. Therefore, we analyzed the biological interactions of metabolic features with the degree of tumor differentiation and the level of malignant potential in 41 patients with completely resectable HCC. The expression levels in resected samples of mRNAs encoded by genes related to tumor metabolism and metastasis were investigated, and the correlation between these expression levels and degrees of differentiation was analyzed. Of the 41 patients, 2 patients had grade I, 27 had grade II, and 12 had grade III tumors. Reductions in the levels of 3-hydroxyacyl-CoA dehydrogenase (HADHA) and acyl-CoA oxidase (ACOX)-2 mRNAs, and increases in pyruvate kinase isoenzyme type M2 (PKM2) mRNA were significantly correlated with the progression of de-differentiation. Analysis of partial correlation coefficients showed that the level of PKM2 mRNA expression was significantly correlated with those of pro-angiogenic genes, vascular endothelial growth factor (VEGF) and ETS-1. Moreover, the levels of VEGF-A and ETS-1 mRNA expression were independently correlated with that of the epithelial-mesenchymal transition (EMT)‑related gene SNAIL. These findings suggest that reductions in fatty acid oxidation and responses to hypoxia may affect the progression of malignant phenotypes in HCC.

The Transcription Factor GLI1 Mediates TGFβ1 Driven EMT in Hepatocellular Carcinoma via a SNAI1-Dependent Mechanism

The role of the epithelial-to-mesenchymal transition (EMT) during hepatocellular carcinoma (HCC) progression is well established, however the regulatory mechanisms modulating this phenomenon remain unclear. Here, we demonstrate that transcription factor glioma-associated oncogene 1 (GLI1) modulates EMT through direct up-regulation of SNAI1 and serves as a downstream effector of the transforming growth factor-β1 (TGFβ1) pathway, a well-known regulator of EMT in cancer cells. Overexpression of GLI1 increased proliferation, viability, migration, invasion, and colony formation by HCC cells. Conversely, GLI1 knockdown led to a decrease in all the above-mentioned cancer-associated phenotypes in HCC cells. Further analysis of GLI1 regulated cellular functions showed that this transcription factor is able to induce EMT and identified SNAI1 as a transcriptional target of GLI1 mediating this cellular effect in HCC cells. Moreover, we demonstrated that an intact GLI1-SNAI1 axis is required by TGFβ1 to induce EMT in these cells. Together, these findings define a novel cellular mechanism regulated by GLI1, which controls the growth and EMT phenotype in HCC.

Thrombocytopenia in Relation to Tumor Size in Patients with Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) size at diagnosis is important in management. Without screening programs, tumor size at diagnosis is heterogeneous. Aims: To examine the clinical parameters related to tumor size. Methods: Using prospectively collected data from a 1,100-patient biopsy-proven HCC cohort presenting in the absence of screening, tumor sizes were ordered and trichotomized and the resulting terciles were compared for tumor and blood parameters. Results: The terciles were significantly different with respect to portal hypertension and thrombocytopenia, which were present in a higher percent of tercile I patients with smaller tumors. Tercile III patients with larger HCCs had the highest serum α-fetoprotein (AFP), γ-glutamyl transpeptidase (GGTP), and alkaline phosphatase (ALKP) levels and the most portal vein (PV) thrombosis. Subclassification of tercile I patients by AFP showed that patients with high serum AFP had increased numbers of tumor nodules, more PV thrombosis, higher bilirubin, ALKP, and GGTP levels, and shorter survival. Conclusions: Smaller-tumor tercile I patients had more advanced portal hypertension with thrombocytopenia than did larger-tumor patients. Tercile I patients with higher AFP levels had more frequent PV thrombosis and worse survival than those with lower AFP levels. Elevated serum GGTP and ALKP levels appear to be associated with a more aggressive HCC phenotype. These differing patterns suggest more than one HCC pathway.

CD44s Regulates the TGF-β–Mediated Mesenchymal Phenotype and Is Associated with Poor Prognosis in Patients with Hepatocellular Carcinoma

The prognosis for individuals diagnosed with hepatocellular carcinoma (HCC) remains poor because of the high frequency of invasive tumor growth, intrahepatic spread, and extrahepatic metastasis. Here, we investigated the role of the standard isoform of CD44 (CD44s), a major adhesion molecule of the extracellular matrix and a cancer stem cell marker, in the TGF-β-mediated mesenchymal phenotype of HCC. We found that CD44s was the dominant form of CD44 mRNA expressed in HCC cells. Overexpression of CD44s promoted tumor invasiveness and increased the expression of vimentin, a mesenchymal marker, in HCC cells. Loss of CD44s abrogated these changes. Also in the setting of CD44s overexpression, treatment with TGF-β1 induced the mesenchymal phenotype of HCC cells, which was characterized by low E-cadherin and high vimentin expression. Loss of CD44s inhibited TGF-β-mediated vimentin expression, mesenchymal spindle-like morphology, and tumor invasiveness. Clinically, overexpression of CD44s was associated with low expression of E-cadherin, high expression of vimentin, a high percentage of phospho-Smad2-positive nuclei, and poor prognosis in HCC patients, including reduced disease-free and overall survival. Together, our findings suggest that CD44s plays a critical role in the TGF-β-mediated mesenchymal phenotype and therefore represents a potential therapeutic target for HCC.

PMO-135 Zinc finger e-box binding homeobox 1 (ZEB1) induces epithelial to mesenchymal transition (EMT) and promotes tumour progression in hepatocellular carcinoma (HCC)

IntroductionHCC is the leading cause of cancer related mortality world wide. Emerging evidence suggests aberrant activation of an embryological trans-differentiation programme termed epithelial-mesenchymal transition (EMT) is critical in promoting metastasis...