Messages from the Border: Novel Insights in Signal Transduction Pathways Involved in Tumor Invasion and Metastasis

Abstract

Cancer is a multistep process encompassing the transformation of normal epithelial cells to the stromal invasion and metastasis, with these last considered the final stage of the disease. Tumor invasiveness is based on creation of a specific peri-tumoral environment which on turn depends upon epithelial-stromal interactions, degradation of extracellular matrix and reorganization of fibrillar components. Even though several aspects of the stromal and cellular remodeling have been elucidated and described, such as the epithelial-mesenchymal transition (EMT) and extracellular matrix degradation, all the underlying molecular mechanism are far to be elucidated in their complexity. In this review we focused on new actors such as microRNAs, G protein coupled receptor kinases (GRKs) and Calcium/calmodulin-dependent protein kinase (CaMKs) known to be involved in several important physiological processes like development, cell differentiation and cell signaling, and more recently linked to tumor progression and invasion.