Tensegrity model hypothesis: may this paradigm be useful to explain hepatic and pancreatic carcinogenesis in patients with persistent hepatitis B or hepatitis C virus infection?

CONTEXT: Hepatitis B (HBV) and hepatitis C virus (HCV) possess well-known oncogenic properties and may promote carcinogenesis in liver. However antigens and replicative sequences of HBV/HCV have been also detected in different extra-hepatic tissues, including the pancreas. Although epidemiological studies and meta-analyses have recently suggested that HBV/HCV may be also risk factors for pancreatic cancer and several researches have investigated the possible mechanisms and intra-/extra-cellular paths involved in pancreatic and hepatic carcinogenesis, to date, these complex processes remain largely unexplained. OBJECTIVES: In our paper, we aimed to propose a comprehensive and qualitative hypothetical model, describing how HBV/HCV may exert their oncogenic role. METHODS: We performed a systematic research of scientific literature, by searching MEDLINE, the Cochrane Library and EMBASE databases. The used keywords were: "chronic HBV/HCV", "pancreatic cancer", "liver carcinoma", "carcinogenesis mechanisms", "tensional integrity", "cytoskeleton", and "extracellular matrix". RESULTS: Taking advantage from available studies, we suggest an unifying hypothesis based on results and data, obtained from different areas of research. In particular we considered the well-defined model of tensional integrity and correlated it to changes induced by HBV/HCV in viscoelastic properties/stiffness of cellular/extracellular microenvironments. These events perturb the tightly-regulated feedback loop, which usually couples the intracellular-generated forces to substrate rigidity of extracellular compartments. Therefore, such a change strongly affects intracellular functions and cellular fate, by promoting a substantial deregulation of critical intracellular biochemical activities and genome expression. CONCLUSIONS: Our hypothesis might provide for the first time a reliable system, which correlates tensional integrity model with intra-/extra-cellular modifications, occurring in liver and pancreas during HBV/HCV-induced carcinogenesis. This approach might improve our understanding of pathogenetic mechanisms involved in the development of pancreatic and hepatic carcinogenesis , enhancing the possibility of their treatment. Furthermore, should the usefulness of this model be definitively confirmed, it might be also helpful to extend its field of application to other viruses-related cancers.