A variety of factors such as genetic and epigenetic alterations is known to be involved in initiation and progression of the malignant lesion. microRNA dysregulation is identified as one of the epigenetic changes during cancer development. They play important roles in modulating range of pathways including cell differentiation apoptosis, cell invasion, Epithelial-mesenchymal transition (EMT) and angiogenesis. Angiogenesis is a vital process for cancer survival. The process of angiogenesis in malignancy is initially and mainly promoted by vascular endothelial growth factors (VEGFs). Over-expression of VEGF-A in different carcinomas has been reported, and its cross-talk has been described in cancer between angiogenesis and epithelial-to-mesenchymal transition (EMT) process. EMT is a process which generates motile and invasive cells and converts epithelial cells into mesenchymal cells. Subsequently, cells acquire migratory abilities, accumulate resistance to different types of cancer therapies and gain stem-cell like properties.
