Malignant mesothelioma (MM) is a rare but highly aggressive cancer that primarily originates from the pleura, peritoneum or pericardium. There is a well-established link between asbestos exposure and progression of MM. Direct invasion of the surrounding tissues is the main feature of MM, which is dependent on dysregulated communication between the mesothelium and the microenvironment. This communication is dependent on the dynamic organization of the cytoskeleton. We have analyzed the organization and function of key cytoskeletal components in MM cell lines of increasing malignancies measured as migratory and invasive properties, and we show that highly malignant and invasive MM cells have an organization of the actin filament and vimentin systems that is distinct from the less malignant MM cell lines. In addition, the Hippo tumor suppressor pathway was inactivated in the invasive MM cells, which was seen as increased YAP nuclear localization.
Keywords: YAP; actin dynamics; cytoskeleton; malignant mesothelioma; vimentin.