Laminin-5 in diseases of the oral cavity

Abstract

The basement membrane molecule laminin forms a family of proteins. Laminin-5 was identified as key protein in the anchoring filaments of the basement membrane. The anchoring filaments connect the basement membrane to the epithelial cells and together form the epithelial adhesion complex. Disturbances in the epithelial adhesion complex result in subepithelial blistering dermatosis. Autoantibodies against laminin-5 are found in cicatricial pemphigoid. Mutations in genes of laminin-5 with loss of the protein cause epidermolysis bullosa Herlitz. It can be determined during prenatal genetic diagnostic testing. Laminin-5 supports migration of keratinocytes and forms the basis for migrating keratinocytes in oral wound healing. Positive re-epithelialization via laminin-5 has been the subject of experimental studies. Oral squamous cell carcinomas are found to have a focal loss of laminin-5 in conjunction with a loss of the cellular receptor, and increased synthesis of laminin-5 by budding tumor cells has been observed along with deposition of the protein in the stroma. As a result of these observations laminin-5 has been suggested as a route of invasion. Quantitative assessment of this phenomenon and the modulation of laminin-5-tumor cell interaction offer new and hopeful means of describing and affecting the invasive behaviour of oral squamous carcinoma.