beta-catenin in oral cancer: an update on current knowledge.

beta-Catenin is a multiple function protein. These functions derive from its interactions with other cell proteins, both on the cell membrane, in the cytoplasm and in the nucleus. beta-Catenin forms a complex with the adhesion molecule E-cadherin, promoting cell-cell adhesion and thereby preventing the cell dissociation that is required for cancer invasion and progression mechanisms. There is also a dynamic pool of cytoplasmic beta-catenin that serves as connection between the extracellular microenvironment and the nucleus. Cytoplasmic beta-catenin acts as a transcription factor for the nucleus in the canonical Wnt pathway, activating the transcription of various genes. Structural or functional alterations of beta-catenin can promote cancer progression. This review addresses the current knowledge on the implications of beta-catenin in the development of oral cancer.