Phenotype Of Hepatocellular Carcinoma Research Articles

Abstract 2408: CD44s is required for a tumor-initiating stem-like mesenchymal phenotype in hepatocellular carcinoma via ligand-independent c-Met activation

Abstract c-Met, a high affinity receptor for hepatocyte growth factor (HGF), plays a critical role in cancer growth, invasion and metastasis. Hepatocellular carcinoma (HCC) patients with active HGF/c-Met signaling have a significantly worse prognosis. CD44, the receptor for hyaluronic acid, is utilized as a surface marker to identify mesenchymal tumor-initiating stem-like cells (TISC) in several cancers. CD44v6 (spice variant 6) has been shown to promote HGF activation of c-Met. In this work, we examine the role of CD44s as a deregulator and activator of c-Met signaling in HCC. In a transcriptome profile analysis of 149 human HCC cases, we identified a significant positive correlation (R2=0.8993) between up-regulated CD44 and c-Met expression. The human HCC cell lines MHCC97-H and Huh7 were further utilized to investigate the direct relationship between c-Met and CD44s. Metastatic MHCC97-H cells are 95% CD44+ and demonstrate ligand-independent c-Met activation. CD44+/c-Met+ MHCC97-H cells demonstrate a mesenchymal phenotype with low expression of E-cadherin, high level of tumorsphere formation, increased expression of fibronectin and Zeb2 compared to Huh7 cells, which have are CD44neg/c-Metneg. In MHCC97-H cells, a direct interaction between CD44s and c-Met was demonstrated by immunoprecipitation/immuno-blot analysis. Transient and stable inhibition of c-Met in MHCC97-H cells results in increased E-cadherin, decreased CD44s, and reduced tumor-initiating characteristics and loss of tumorsphere formation. Likewise, inhibition of CD44s demonstrates similar phenotype with increased E-cadherin, decreased tumorsphere formation, and decreased c-Met activation and loss of downstream Akt and Erk phosphorylation. CD44s knockdown recovered c-Met to a regulated HGF-dependent state. Selective inhibition of either PI3K (Ly294002) or MAPK (PD98059) pathways in MHCC97-H cells demonstrate that PI3K/Akt activation signals drive CD44s expression in a feed forward fashion. Conversely, the over-expression of CD44s in Huh7 cells demonstrates a mesenchymal phenotype with fibroblastic-like cell morphology, decreased E-cadherin, increased Zeb1, increased PI3K/Akt signaling, and increased tumorsphere formation compared to control Huh7 cells. Selective inhibition of PI3K/Akt signaling in CD44+ Huh7 cells resulted in reduced CD44s expression and decreased tumorsphere formation. In conclusion, CD44s induces a mesenchymal phenotype and tumor initiating characteristics in HCC through the deregulation of c-Met and activation of a positive feedback loop through PI3K/Akt signaling. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2408. doi:1538-7445.AM2012-2408

Expression of both hepatocellular carcinoma and cholangiocarcinoma phenotypes in hepatocellular carcinoma and cholangiocarcinoma components in combined hepatocellular and cholangiocarcinoma

Expression of phenotype markers of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) in HCC and CC components of 20 combined hepatocellular and cholangiocarcinomas (CHCs) of the liver was investigated immunohistochemically. Both HCC and CC components of all CHCs expressed at least one of the CC phenotype markers [cytokeratin (CK)-7, CK-19, and carbohydrate (CA) 19-9]. HCC components in 90% of CHCs and CC components in 95% of CHCs expressed at least one of these CC phenotype markers in more than 40% of cancer cells. HCC components in all CHCs expressed at least one of the HCC phenotype markers [hepatocyte antigen (HA), α-fetoprotein (AFP), and canalicular carcinoembryonic antigen]. HCC components in 90% of CHCs and CC components in 75% of CHCs expressed HA, AFP, or both. HCC components in 75% of CHCs and CC components in 60% of CHCs expressed HA, AFP, or both in more than 10% of cancer cells. The present results show that both HCC and CC components of most of the CHCs expressed both HCC and CC phenotypes, supporting the hypothesis that CHC originates from a hepatic progenitor cell capable of differentiating into hepatocytes and cholangiocytes.

Quantification of Endostatin, Angiostatin and Thrombospondin-1 Expression in Hepatocellular Carcinoma Using a Quantitative Real Time Polymerase Chain Reaction

Purpose: Tumor angiogenesis, a major requirement for tumor growth and metastasis, is regulated by pro- and anti-angiogenic factors. Hepatocellular carcinoma (HCC) has become a common malignant tumor and is characterized by a high vascularity. In this study, expression of endostatin, angiostatin and thrombospondin-1 (TSP-1) were analyzed and correlated with clinicopathological and radiological features of HCC. Methods: Expression of endostatin, angiostatin and TSP-1 were analyzed by quantitative real time-polymerase chain reaction (qRT- PCR) in 67 HCC patients (23HBV, 22HCV, 22NBNC) with mean age 59.09 ± 11.13 years (60 M: 7 F), 9 cirrhosis patients (2HBV, 2HCV, 5ALD) with mean age 48.33 ± 11.31 years (8 M:1 F) and 14 chronic hepatitis patients (7HBV, 7HCV) with mean age 48.33 ± 7.17 years (10 M: 4 F) respectively. HCC was diagnosed on the basis of EASL (European Association for the Study of the Liver) criteria. Results: Expression of endostatin was found to be significantly higher in patients with HCC compared with cirrhosis and chronic hepatitis. Although angiostatin and TSP-1 expression were higher in HCC compared to cirrhosis and chronic hepatitis but the difference was not statistically significant. The difference in the expression of endostatin, angiostatin and TSP-1 in cirrhosis and chronic hepatitis were not significant. No correlation of endostatin, angiostatin and TSP-1 was seen with the tumor size, tumor number, tumor localization, portal vein thrombosis, cirrhosis, etiology, AST, ALT and platelets. Conclusion: Endostatin, angiostatin and TSP-1 were highly expressed in HCC patients and act as a compensatory response to the angiogenic phenotype of HCC. Further studies with a larger number of patients need to be done.

Tools for monitoring patients with hepatocellular carcinoma on the waiting list and after liver transplantation

Norman Kneteman, Tito Livraghi, David Madoff, Eduardo de Santibanez, and Michael Kew Division of Transplantation, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada; Department of Interventional Radiology, Istituto Clinico Humanitas, Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy; Division of Interventional Radiology, New York-Presbyterian/Weill Cornell Medical Center, New York, NY; General Surgery and Liver Transplant Unit, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina; and Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa

Increased CD4+CD69+CD25‐ T cells in patients with hepatocellular carcinoma are associated with tumor progression

A new subset of Treg cells, CD4(+) CD69(+) CD25(-) T cells, has been identified in mice. Herein, we aimed to identify this subset of T cells and to evaluate its function in patients with hepatocellular carcinoma (HCC). We detected CD4(+) CD69(+) CD25(-) T cells and its expression of CCR6 and transforming growth factor-β1 (TGF-β1) in peripheral blood of 91 HCC patients, 38 chronic hepatitis patients and 34 healthy donors by flow cytometry. CD4(+) CD69(+) CD25(-) T cells in HCC tissues were also analyzed. CD4(+) CD69(+) CD25(-) T cells were significantly increased in peripheral blood of HCC patients compared with healthy persons and chronic hepatitis patients (8.74% ± 0.42% vs 4.55% ± 0.33% and 5.15% ± 0.36%, P < 0.0001). The percentage of peripheral CD4(+) CD69(+) CD25(-) T cells was significantly higher in HCC patients with Tumor Node Metastasis (TNM) stage III plus IV (P < 0.05). Patients with large tumor size and tumor vascular invasion were inclined to obtain high percentage of CD4(+) CD69(+) CD25(-) T cells (P < 0.05). The frequency of membrane-bound TGF-β1 positive cells in CD4(+) CD69(+) CD25(-) T cells from HCC patients was higher than that from the other two groups (P < 0.0001). A considerable proportion of CD4(+) CD69(+) CD25(-) T cells were present in HCC tissues, which has significant correlation with tumor size and TNM stage. Few CD4(+) CD69(+) CD25(-) T cells express CCR6 both in peripheral blood and tumor tissues from HCC patients. Increased CD4(+) CD69(+) CD25(-) T cells in HCC patients are significantly correlated with tumor size, vascular invasion and TNM stage. Thus, increased CD4(+) CD69(+) CD25(-) T cells exert a critical role in HCC progression and might be a clinically aggressive phenotype of HCC.

Are non‐traditional CD4+CD69+CD25– regulatory T cells involved in disease progression of human hepatocellular carcinoma?

See article in J. Gastroenterol. Hepatol. 2011; 26: 1519–1526.

MicroRNA122 is a key regulator of α-fetoprotein expression and influences the aggressiveness of hepatocellular carcinoma

α-fetoprotein (AFP) is not only a widely used biomarker in hepatocellular carcinoma (HCC) surveillance, but is also clinically recognized as linked with aggressive tumour behaviour. Here we show that deregulation of microRNA122, a liver-specific microRNA, is a cause of both AFP elevation and a more biologically aggressive phenotype in HCC. We identify CUX1, a direct target of microRNA122, as a common central mediator of these two effects. Using liver tissues from transgenic mice in which microRNA122 is functionally silenced, an orthotopic xenograft tumour model, and human clinical samples, we further demonstrate that a microRNA122/CUX1/microRNA214/ZBTB20 pathway regulates AFP expression. We also show that the microRNA122/CUX1/RhoA pathway regulates the aggressive characteristics of tumours. We conclude that microRNA122 and associated signalling proteins may represent viable therapeutic targets, and that serum AFP levels in HCC patients may be a surrogate marker for deregulated intracellular microRNA122 signalling pathways in HCC tissues.

Genetic and Epigenetic Signatures in Human Hepatocellular Carcinoma:A Systematic Review

Hepatocellular carcinoma (HCC) is the third most common cause of cancer deaths worldwide, and the incidence of this fatal disease is still on rise. The majority of HCCs emerge in the background of a chronic liver disease, such as chronic hepatitis and liver cirrhosis. The current understanding is that majority of HCCs evolve as a consequence of chronic inflammation and due to the presence of infection with hepatitis viruses. These underlying pathogenic stimuli subsequently induce a spectrum of genetic and epigenetic alterations in several cancer-related genes, which are involved in cell-cycle regulation, cell growth and adhesion. Such widespread genomic alterations cause disruption of normal cellular signaling and finally lead to the acquisition of a malignant phenotype in HCC. In general, the type of gene alterations, such as point mutations, deletion of chromosomal regions and abnormal methylation of gene promoters differ according to the individual targeted gene. In HCC, incidence of genetic alterations is relatively rare and is limited to a subset of few cancer-specific genes, such as the tumor suppressor p53, RB genes and oncogenes such as the CTNNB1. In contrast, epigenetic changes that involve aberrant methylation of genes and other post-transcriptional histone modifications occur far more frequently, and some of these epigenetic alterations are now being exploited for the development of molecular diagnostic signatures for HCC. In addition, recent findings of unique microRNA expression profiles also provide an evidence for the existence of novel mechanisms for gene expression regulation in HCC. In this review article, we will review the current state of knowledge on the activation of various oncogenic pathways and the inactivation of tumor suppressor pathways in HCC that result in the disruption of cancer-related gene function. In addition, we will specifically emphasize the clinical implication of some of these genetic and epigenetic alterations in the management of hepatocarcinogenesis.

Thrombin is a therapeutic target for metastatic osteopontin-positive hepatocellular carcinoma

We previously identified osteopontin (OPN) as a promoter and thus a potential therapeutic target for hepatocellular carcinoma (HCC) metastasis. The serine protease thrombin interacts with OPN and can modify its biological activity. To explore the role of thrombin alone or in conjunction with OPN in HCC, we studied the correlation of thrombin levels to HCC prognosis in patients with various OPN levels, and evaluated the effects of OPN fragments generated by thrombin cleavage on proliferation and adhesion of HCC cells. We found that the thrombin level was strongly associated with the metastatic potential of HCC cell lines, and that thrombin was remarkably overexpressed in HCC tissue compared with adjacent nontumor tissue. In addition, HCC tissue from patients with recurrent disease displayed much higher thrombin levels, particularly in those with elevated OPN levels. Only HCCs with elevated OPN levels had a significant correlation between high thrombin levels and overall survival (OS; P < 0.01), or time to recurrence (TTR; P < 0.0001) of HCC. Multivariate analysis revealed that thrombin was an independent prognostic indicator. In vitro assays demonstrated that thrombin promotes the proliferation and adhesion of OPN+ HCC cells. Furthermore, thrombin activated the focal adhesion kinase (FAK) pathway of OPN+ HCC cells, which was blocked by the inhibition of integrin β1. Thrombin plays an important role in OPN-mediated aggressive phenotype of HCC through activation of integrin β1-FAK signaling, and is an independent poor prognostic factor for HCC. Thus, thrombin may be a potential therapeutic target to inhibit HCC metastasis in OPN+ patients.

Abstract A16: Thrombin promotes hepatocellular carcinoma metastasis via mediating osteopontin-dependent tumor growth and adhesion activity

Abstract In our previous study, osteopontin (OPN) was identified as one of the leading genes that promote the metastasis of hepatocellular carcinoma (HCC), and a potential therapeutic target for HCC metastasis. The serine protease thrombin can interact with OPN and modify its biologic activity. To explore the role of thrombin alone or collaborating with OPN in HCC, we investigated the thrombin level and its correlation to the prognosis of 72 HCCs with different OPN backgrounds using real-time PCR and Western blot, and evaluated the effects of OPN fragments formed by thrombin cleavage on in vitro proliferation and adhesion of HCC cells. We found that the expression level of thrombin was positively related to the metastatic potentials of HCC cell lines, and was remarkably overexpressed in HCCs compared with the adjacent nontumor tissues. In addition, HCC tissues from patients with recurrent disease displayed much higher thrombin levels, particularly in those with OPN overexpressed. In the immunohistochemical study of 230 HCCs, only in those with a higher OPN level, a significant association was found between the higher thrombin level and the overall survival (OS; P &amp;lt; 0.01) and time to recurrence (TTR; P &amp;lt; 0.0001) of patients. Assays in vitro demonstrated that thrombin could promote the proliferation and adhesion of OPN+ HCC cells. And N-terminal of OPN showed better effects on the proliferation and adhesion abilities of HCC cells than the intact protein. Thrombin treatment could activate FAK pathway of OPN+ HCC cells, and this activation was blocked by the inhibition of integrin β1. Conclusions: Thrombin plays an important role in OPN-mediated aggressive phenotype and poor prognosis of HCC, which may be through the activation of the integrin β1 -FAK signaling. So, thrombin might be a potential therapeutic target to combat HCC progression in thrombin+/OPN+ patients. Citation Information: Clin Cancer Res 2010;16(14 Suppl):A16.

720 Simultaneous HER2/neu and PTEN deregulation correlates with aggressive phenotype in hepatocellular carcinoma: a tissue microarray analysis

720 Simultaneous HER2/neu and PTEN deregulation correlates with aggressive phenotype in hepatocellular carcinoma: a tissue microarray analysis

Activation of β-Catenin by Hypoxia in Hepatocellular Carcinoma Contributes to Enhanced Metastatic Potential and Poor Prognosis

Aberrant activation of beta-catenin contributes to the malignant phenotype in hepatocellular carcinoma (HCC). Hypoxia is also known to promote HCC invasion and metastasis. However, the association between beta-catenin and the proinvasive role of hypoxia remains unclear. We investigated the role of beta-catenin in the proinvasive consequences of hypoxia in HCC. We established in vitro and in vivo hypoxic models to investigate the expression of beta-catenin in hypoxic HCC cells and its role in hypoxia-induced aggressiveness. The clinical significance of beta-catenin and/or hypoxia-induced factor-1alpha (HIF-1alpha) was evaluated using HCC tissue microarrays. Hypoxia induced beta-catenin overexpression and/or intracellular accumulation in four HCC cell lines through downregulating the endogenous degradation machinery, and promoted in vitro invasion and in vivo metastasis of MHCC97 and Hep3B cells. Besides morphologic changes, hypoxic MHCC97 and Hep3B cells exhibited molecular alterations consistent with epithelial-mesenchymal transition, characterized by the loss of epithelial cell markers (E-cadherin and plakoglobin) and upregulation of mesenchymal markers (vimentin and N-cadherin), as well as the increase of matrix metalloproteinase 2. However, silencing beta-catenin in these hypoxic cells reversed epithelial-mesenchymal transition and repressed metastatic potential. Positive expression of beta-catenin in HCC tissue microarray was associated with the expression of HIF-1alpha (P=0.034), and coexpression of beta-catenin and HIF-1alpha in HCC was correlated with shorter overall survival and time to recurrence. beta-Catenin in HCC is activated by hypoxia and contributes to hypoxia-induced metastatic potential.

Abstract 2959: Characterization and function of unique T-cell factor-4 splicing isoforms that exhibit tumor repressive phenotypes in hepatocellular carcinoma

Abstract Background and Aims: The canonical Wnt signaling is frequently activated in hepatocellular carcinoma (HCC). Although β-catenin is the principle effector protein of Wnt signaling, the success of relaying signals to the nucleus depends on the T-cell factor (TCF) family of transcription factors that bind to promoters of Wnt-responsive target genes. The human TCF-4 gene (TCF7L2) is composed of 17 exons with multiple alternative splicing sites. In spite of theoretical possibility of constructing more than 500 isoforms, only two TCF-4 splice variants have been identified so far. Therefore, the objective of this study is to identify different TCF-4 isoforms and explore their putative role in hepatic oncogenesis. Methods: The TCF-4 isoforms were detected by RT-PCR. Their expression was confirmed by using RT-PCR with splice site-specific primer pairs in HCC cell lines, HCC tumor and peritumor tissues, and normal liver. To examine their functional properties, mammalian expression plasmids encoding each isoform were prepared and protein products were verified by Western blotting. The TCF transcriptional activity, cell proliferation, migration and transformation were measured to evaluate their biological functions. Results: We identified and subsequently cloned 14 different TCF-4 splicing variants derived from HCC cell lines. Two previously known forms TCF-4B (short) and TCF-4E (long) were found among the 14 isoforms. The 12 new isotypes were named in alphabetical order according to increasing size of their protein products. Out of the 14 TCF-4 isoforms, we have detected 8 short forms (A-I except for E), 5 long forms (J-M plus E), and a novel isoform designated as TCF-4X. The structure of TCF-4X included an extra exon, labeled as exon 5a, between exons 5 and 6 indicating that TCF7L2 may have 18th exon in the genome. Functional analysis of these isotypes revealed several distinctive phenotypes. TCF-4B showed the highest TCF transcriptional activity and enhanced cell growth rate, but lower cell migration and transforming ability compared to control. TCF-4J exhibited lower transcriptional activity but the highest cell proliferation, migration and colony formation rate. In contrast, TCF-4K displayed the lowest TCF transcriptional activity, inhibited cell proliferation, and eliminated colony-forming ability. In addition, their expression profile by RT-PCR indicated that TCF-4J was highly expressed in HCC tumors compared to peritumor and normal liver, while TCF-4K was barely detected in HCC cell lines and tumor tissues. Conclusions: Our study demonstrates that at least 14 different TCF-4 isoforms are expressed in HCC and their function is distinguishable based on the structure of the splicing sites. Whereas the TCF-4J isoform produced the most characteristic features of the malignant phenotype, TCF-4K exhibited tumor repressive traits. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2959.

Nuclear β-Catenin Induces an Early Liver Progenitor Phenotype in Hepatocellular Carcinoma and Promotes Tumor Recurrence

Transforming growth factor-beta cooperates with oncogenic Ras to activate nuclear beta-catenin during the epithelial to mesenchymal transition of hepatocytes, a process relevant in the progression of hepatocellular carcinoma (HCC). In this study we investigated the role of beta-catenin in the differentiation of murine, oncogene-targeted hepatocytes and in 133 human HCC patients scheduled for orthotopic liver transplantation. Transforming growth factor-beta caused dissociation of plasma membrane E-cadherin/beta-catenin complexes and accumulation of nuclear beta-catenin in Ras-transformed, but otherwise normal hepatocytes in p19(ARF)-/- mice. Both processes were inhibited by Smad7-mediated disruption of transforming growth factor-beta signaling. Overexpression of constitutively active beta-catenin resulted in high levels of CK19 and M2-PK, whereas ablation of beta-catenin by axin overexpression caused strong expression of CK8 and CK18. Therefore, nuclear beta-catenin resulted in dedifferentiation of neoplastic hepatocytes to immature progenitor cells, whereas loss of nuclear beta-catenin led to a differentiated HCC phenotype. Poorly differentiated human HCC showed cytoplasmic redistribution or even loss of E-cadherin, suggesting epithelial to mesenchymal transition. Analysis of 133 HCC patient samples revealed that 58.6% of human HCC exhibited strong nuclear beta-catenin accumulation, which correlated with clinical features such as vascular invasion and recurrence of disease after orthotopic liver transplantation. These data suggest that activation of beta-catenin signaling causes dedifferentiation to malignant, immature hepatocyte progenitors and facilitates recurrence of human HCC after orthotopic liver transplantation.

Biliary phenotype of hepatocellular carcinoma after preoperative transcatheter arterial chemoembolization

Transcatheter arterial chemoembolization (TACE) is now the mainstay of treatment for non-curative hepatocellular carcinoma (HCC), and hoped to have chemotherapeutic and ischemic effects; however, the histopathological changes of HCC caused by TACE have not been sufficiently discussed so far. We aimed to assess the morphological and immunohistochemical features of HCC treated with TACE by immunostaining cytokeratin (CK) 7, CK14, CK19 and vimentin, and to correlate these data with observed clinicopathological characteristics. Eighty cases of surgically resected HCC with preoperative TACE and 146 cases of HCC resected without TACE as a control were analyzed. The incidences of intrahepatic metastasis, poorly differentiated histology, multinucleated giant cells, mitotic figures and cytoplasmic inclusion bodies in the TACE group were significantly higher than those in the non-TACE group. The TACE group showed reactivity for CK7 in 56.3% (45/80) of patients, CK14 in 12.5% (10/80), CK19 in 23.8% (19/80) and vimentin in 6.3% (5/80) of patients. CK19 expression in the TACE group was significantly higher than in the non-TACE group (P = 0.0423). There was no correlation between immunoreactivity and the number of times TACE was carried out, but the expression of CK19 and vimentin in the massive necrotic group was higher than that in the mild necrotic group (P = 0.0197, P = 0.0229, respectively). Only TACE was an independent determinant of CK19 expression in all cases by multivariate analysis. These results suggest that preoperative TACE may have an impact on the biliary phenotype of HCC. Some post-therapeutic HCC patients might develop HCC with a biliary phenotype indicating more aggressive malignancies.

Capn4 overexpression underlies tumor invasion and metastasis after liver transplantation for hepatocellular carcinoma #

Liver transplantation (LT) is one of the best therapeutic options for nonresectable hepatocellular carcinoma (HCC). Unfortunately, some HCC patients succumb to the disease after LT, which reduces long- and medium-term survival. To identify the proteins associated with HCC invasion and metastasis, HCC patients undergoing LT with complete follow-up data were included in this study and were categorized into recurrence and nonrecurrence groups. We extracted the total protein from the acquired homogeneous tumor cells and applied a cleavable isotope-coded affinity tag technology to quantitate relative changes in protein levels between the two groups. We identified a total of 149 proteins with two-dimensional liquid chromatography coupled with tandem mass spectrometry, including 52 differentially expressed proteins by at least two-fold. Among them, calpain small subunit 1 (Capn4), a protein with relevant interactions with many migration-invasion-related proteins, has attracted more attention. First, Capn4 overexpression in the recurrence group was confirmed via real-time polymerase chain reaction and western blotting in another cohort of 40 HCC patients undergoing LT. Second, Capn4 was associated with enhanced invasiveness in vitro. The small interfering RNA-mediated knockdown expression of Capn4 in HCC cell lines significantly inhibited its mobile and invasive ability. Tissue microarray in a further 192 cases revealed that Capn4 significantly correlated with invasive phenotype of HCC, and univariate and multivariate analyses indicated that Capn4 is an independent prognostic factor for recurrence and survival of HCC patients. Our study revealed that Capn4 overexpression underlies invasion and metastasis after LT for HCC and might be a candidate biomarker for future diagnosis and a target for therapy.

Chromogranin A levels in chronic liver disease and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the relevant cause of death in patients with compensated cirrhosis. Alpha-fetoprotein (AFP) is used for screening HCC, with limited success. We evaluated plasma chromogranin A (CgA) as a marker of HCC. CgA plasma levels and AFP serum levels were prospectively measured in 30 patients with HCC, 14 with cirrhosis, 79 with chronic hepatitis and 65 controls. CgA was measured with an enzyme-linked immunosorbent assay (DAKO A/S Glostrup, Denmark). AFP was measured by electrochemiluminoimmunoassay (Elecsys, Roche S.p.A., Italy). CgA levels were significantly higher in the three groups of patients than in controls and in patients with HCC they were significantly higher than in chronic hepatitis patients [median 44.5 (interquartile range 21-145.9)U/L vs. 15.3 (10.9-29.25)U/L, p<0.001]. AFP values were above the upper reference limit in 75% of patients with HCC, 50% of cirrhotic patients and 11% of chronic hepatitis patients (p<0.005). CgA values significantly correlated with AFP levels (r(s)=0.42, p<0.0001). The overall diagnostic accuracy of CgA was 75% (CI 66-82), with a sensitivity of 70% (CI 50.6-85.2) and a specificity of 67% (CI 55.9-76.3). Despite the evidence of higher CgA levels in patients with HCC, this test has low-diagnostic accuracy. Its pathophysiological meaning remains unknown, even if it could suggest an endocrine phenotype of HCC.

Aberrant iNOS signaling is under genetic control in rodent liver cancer and potentially prognostic for the human disease

Mounting evidence underlines the role of inducible nitric oxide synthase (iNOS) in hepatocellular carcinoma (HCC) development, but its functional interactions with pathways involved in HCC progression remain uninvestigated. Here, we analyzed in preneoplastic and neoplastic livers from Fisher 344 and Brown Norway rats, possessing different genetic predisposition to HCC, in transforming growth factor-alpha (TGF-alpha) and c-Myc-TGF-alpha transgenic mice, characterized by different susceptibility to HCC, and in human HCC: (i) iNOS function and interactions with nuclear factor-kB (NF-kB) and Ha-RAS/extracellular signal-regulated kinase (ERK) during hepatocarcinogenesis; (ii) influence of genetic predisposition to liver cancer on these pathways and role of these cascades in determining a susceptible or resistant phenotype and (iii) iNOS prognostic value in human HCC. We found progressive iNos induction in rat and mouse liver lesions, always at higher levels in the most aggressive models represented by HCC of rats genetically susceptible to hepatocarcinogenesis and c-Myc-TGF-alpha transgenic mice. iNOS, inhibitor of kB kinase/NF-kB and RAS/ERK upregulation was significantly higher in HCC with poorer prognosis (as defined by patients' survival length) and positively correlated with tumor proliferation, genomic instability and microvascularization and negatively with apoptosis. Suppression of iNOS signaling by aminoguanidine led to decreased HCC growth and NF-kB and RAS/ERK expression and increased apoptosis both in vivo and in vitro. Conversely, block of NF-kB signaling by sulfasalazine or short interfering RNA (siRNA) or ERK signaling by UO126 caused iNOS downregulation in HCC cell lines. These findings indicate that iNOS cross talk with NF-kB and Ha-RAS/ERK cascades influences HCC growth and prognosis, suggesting that key component of iNOS signaling could represent important therapeutic targets for human HCC.

Development of Hepatocellular Carcinoma in Iqgap2-Deficient Mice Is IQGAP1 Dependent

IQGAPs are multidomain scaffolding proteins that integrate Rho GTPase and Ca2+/calmodulin signals with cell adhesive and cytoskeletal reorganizational events. Targeted disruption of the murine Iqgap2 gene resulted in the age-dependent development of apoptosis and hepatocellular carcinoma (HCC), characterized by the overexpression of IQGAP1, the loss of membrane E-cadherin expression, the cytoplasmic translocation (and activation) of beta-catenin, and the overexpression of a nuclear target of beta-catenin, cyclin D1. In normal hepatocytes, IQGAP2 was found to exist as one component of a multifunctional scaffolding complex comprising IQGAP1, beta-catenin, and E-cadherin, with no evidence for direct IQGAP1-IQGAP2 interactions. Interbreeding of Iqgap2(-/-) mice into the Iqgap1(-/-) background resulted in the phenotypic correction of the preexisting hepatopathy, decreases in the incidence and sizes of HCC tumors, and the normalization of overall survival rates compared to those of Iqgap2(-/-) mice, suggesting that maximal penetrance of the Iqgap2(-/-) HCC phenotype requires the coordinate expression of IQGAP1. These results identify Iqgap2 as a novel tumor suppressor gene specifically linked to the development of HCC and the activation of the Wnt/beta-catenin signaling pathway, while also suggesting that IQGAP1 and IQGAP2 retain functionally divergent roles in hepatocellular carcinogenesis.

Modeling and Analyzing Gene Co-Expression in Hepatocellular Carcinoma Using Actor-Semiotic Networks and Centrality Signatures

Primary hepatocellular carcinoma (HCC) is currently the fifth most common malignancy and the third most common cause of cancer mortality worldwide. Because of its high prevalence in developing nations, there have been numerous efforts made in the molecular characterization of primary HCC. However, a better understanding into the pathology of HCC required software-assisted network modeling and analysis. In this paper, the author presented his first attempt in exploring the biological implication of gene co-expression in HCC using actor-semiotic network modeling and analysis. The network was first constructed by integrating inter-actor relationships, e.g. gene co-expression, microRNA-to-gene, and protein interactions, with semiotic relationships, e.g. gene-to-Gene Ontology Process. Topological features that are highly discriminative of the HCC phenotype were identified by visual inspection. Finally, the author devised a graph signature-based analysis method to supplement the network exploration.