Pathogenesis of Hepatitis B Virus Associated Chronic Liver Disease

Hepatitis B virus (HBV) infection is associated with chronic liver diseases (CLD), which progress from hepatitis to fibrosis, cirrhosis, and finally hepatocellular carcinoma (HCC) over 30–50 years. The pathogenesis of CLD is immune mediated, which is characterized by persistent immune responses against virus infected hepatocytes. During bouts of CLD, the virus gene encoding the hepatitis B x antigen (HBx) is increasingly found integrated at multiple sites within the human genome. Many of these integrated templates express HBx, which is a trans-regulatory protein that supports virus gene expression and replication on one hand, but also alters patterns of gene expression in the infected cell. HBx alters gene expression by constitutively activating signal transduction pathways in the cytoplasm and promoting epigenetic mediated changes in the expression of cellular genes. In doing so, HBx contributes to the persistence of virus infected cells and to the pathogenesis of CLD by triggering multiple hallmarks which are characteristic of cancer

Mutations in the C-terminus of the X protein of hepatitis B virus regulate Wnt-5a expression in hepatoma Huh7 cells: cDNA microarray and proteomic analyses

Background: The hepatitis B virus x gene (HBx) is a promiscuous transactivator implicated in the development of hepatocellular carcinoma (HCC). The present study was designed to investigate the molecular events regulated by HBx. Methods: Genomic and proteomic expression profiling was performed in Huh7 HCC cells transfected with HBx mutants with a C-terminal deletion. The gene and protein expression of wingless-type murine-mammary-tumour virus (MMTV) integration site family, member 5A (Wnt-5a) was validated by analyses of reverse transcription–polymerase chain reaction (RT–PCR), real-time RT–PCR, western blot and immunohistochemistry. Results: Differentially expressed genes and proteins were found in the transfected Huh7 HCC cells; most of them were involved in transcriptional regulation, although others including oncogenes or tumor suppressor genes, and molecules involved in cell junctions, signal transduction pathways, metabolism or the immune response were also observed. The expression of the Wnt-5a gene was elevated >10-fold in Huh7 cells transfected with the HBx3′-30 amino acid deletion mutant. However, the expression was downregulated by the transfection with the HBx3′-40 amino acid deletion mutant. The changes in Wnt-5a expression were also observed in human HCC tissues, compared with corresponding non-cancerous liver tissues. A negative correlation was found between the expression of Wnt-5a and HBx COOH mutations in HCC tissues. Conclusions: HBx mutants may participate in the development and progression of HCC, at least in part through the Wnt-5a pathway

Sustained proliferation in cancer: mechanisms and novel therapeutic targets

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression

Sustained proliferation in cancer: Mechanisms and novel therapeutic targets

Under a Creative Commons license.-- et al.Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression.Drs. Feitelson and Arzumanyan were supported by NIH (AI076535) and by Temple University. Dr. Rob J. Kulathinal was supported by the National Science Foundation, and by the American Cancer Society. Dr. Marino was supported by grant from University Roma Tre (CLA 2013) and by the Italian Association for Cancer Research (no. IG15221). Dr. Georgakilas was supported by the EU Marie Curie Reintegration Grant (MC-CIG-303514), Greek National funds through the Operational Program ‘Educational and Lifelong Learning of the National Strategic Reference Framework (NSRF)- Research Funding Program: THALES (MIS 379346) and COST Action CM1201 ‘Biomimetic Radical Chemistry.’ Dr. Amedei was supported by the Italian Ministry of University and University of Italy. Dr. Amin was supported by the Terry Fox Foundation (TF-36), UAEU Program for Advanced Research (UPAR25183), Al-Jalila Foundation (AJF201454) and Zayed Center for Health Sciences (ZCHS2014). Dr. Sanchez-Garcia was supported by FEDER, by MICINN (SAF2012-32810), by NIH (R01 CA109335-04A1), by Junta de Castilla y León (BIO/SA06/13), by the ARIMMORA project (FP7-ENV-2011, EU 7th Framework Program) and by the EuroSyStem and the DECIDE Network (EU FP7). Dr. Sharma was funded by NIH grants (R01CA131294, CA155686), the Avon Foundation and a Breast Cancer Research Foundation grant (90047965). Dr. Saxena was supported by a grant from NIH (K01DK077137 and R03DK089130). Dr. Singh was supported by the Fast Track Scheme for Young Scientists, Department of Science and Technology, India (SR/FT/LS-063/2008). Dr. Honoki was supported by a grant from the Ministry of Education, Culture, Sports, Science and Technology, Japan (no. 24590493). Dr. Ciriolo was supported by the Italian Association for Cancer Research (AIRC – grant #IG10636). Dr. Aquilano was supported by MIUR-PRIN (20125S38FA 002) and Ministero della Salute (GR-2011-02348047). Dr. Chen was funded from the Ovarian and Prostate Cancer Research Trust, UK. Dr. Mohammed is supported by the Purdue University Center for Cancer Research. W. Nicol Keith & Alan Bilsland were supported by the University of Glasgow, Beatson Oncology Centre Fund, and Cancer Research UK (http://www.cancerresearchuk.org) grant C301/A14762.Peer Reviewe

Human viral oncogenesis: a cancer hallmarks analysis

Approximately 12% of all human cancers are caused by oncoviruses. Human viral oncogenesis is complex, and only a small percentage of the infected individuals develop cancer, often many years to decades after the initial infection. This reflects the multistep nature of viral oncogenesis, host genetic variability, and the fact that viruses contribute to only a portion of the oncogenic events. In this review, the Hallmarks of Cancer framework of Hanahan and Weinberg (2000 and 2011) is used to dissect the viral, host, and environmental cofactors that contribute to the biology of multistep oncogenesis mediated by established human oncoviruses. The viruses discussed include Epstein-Barr virus (EBV), high-risk human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV, respectively), human T cell lymphotropic virus-1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV)