The role of adhesion molecules in oral cancer

Integrins in Head and Neck Squamous Cell Carcinoma (HNSCC): A Review of the Current Literature

Integrins are a family of adhesion molecules performing a major role in multiple cellular functions. Their contribution in carcinogenesis and metastatic process are the object of intense research activity worldwide during the last decades. This review focuses on the existing knowledge about integrin expression in head and neck squamous cell carcinoma (HNSCC) as it has been acquired mainly by immunohistochemical methods and by in vitro assays. The elucidation of the exact role of integrins and the study of expressive alterations of these molecules in cancer cells, may result in novel therapeutical approaches for useful applications in the clinical routine of HNSCC in the future.

Cell adhesion molecules and oral cancer

Cell adhesion molecules (CAMs) are found on the surfaces of all cells, where they bind to extracellular matrix molecules or to receptors on other cells. As well as having a structural role, CAMs function as signaling receptors, transducing signals initiated by cellular interactions which regulate many diverse processes, including cell division, migration, and differentiation. Cell adhesion molecules are essential for maintaining stable tissue structure. However, cell adhesion must be dynamic to facilitate the mobility and turnover of cells. In dynamic situations, cells alter their cell-cell and cell-matrix interactions by virtue of altered expression and function of CAMs. The expression of CAMs is normally tightly regulated, thereby controlling cell proliferation, mobility, differentiation, and survival. Many of these processes are misregulated in malignant tumors, and it has been shown that many of the characteristics of tumor cells are attributable to the aberrant expression or function of CAMs. Integrins and E-cadherin are the most important CAMs expressed by stratified squamous epithelium. Altered expression of these molecules has been found in oral carcinoma, where loss of CAM expression is often seen in poorly differentiated lesions. However, up-regulation of certain integrins, such as alphavbeta6, has consistently been found in oral cancer, suggesting that it may play an active role in disease progression.