Klin Onkol 2003; 16(4): 171-177.
Summary: Changes of intracelullar interactions which are also mediated by the cell adhesion molecules play an important role in the progresion of malignant tumours. Proteins of the CD44 family are cell adhesion molecules, which are ubiquitously expressed on cell membranes of a wide range of tissues. The standard form and it’s variant isoforms are encoded by a single gene. The mechanism of alternative splicing is crucial for formation of different isoforms. CD44 proteins are responsible for maintenance of the cell adhesion during embryogenesis, they play an important role at the process of myelopoesis, lymphopoesis and angiogenesis, in lymhocyte activation and homing and also in hyaluronate degradation. Although the expression and occurence of variant CD44 isoforms in malignant tissues differs obviously from their expression in nonmalignant tissues, the significance of alterations of these proteins in malignant tumours has not been clearly established yet. Apart from the up and down-regulation, changing patterns of variant isoforms expression has been also described in the diverse types of malignant epithelial tumours. This article summarizes recent findings on the expression of CD44 molecules in malignant tissues and reviews CD44 expression in carcinomas of urinary bladder, ovarium, mammary gland and stomach, in renal and hepatocellular carcinoma, squamous carcinoma of head and neck and in non-small cell lung carcinomas.
