CD44 expression and invasiveness in basal cell carcinoma

CD44 represents a family of cellular adhesion molecules that interact with different extracellular components and also with a number of growth factors. At the molecular level, the functional diversity of these molecules is associated with extensive alternative splicing and variable degrees of glycosylation. The interrelation of CD44 expression patterns with tumor growth and invasion is exemplified by our work on basal cell carcinoma. The present article represents an overview of the assessment of the varying expression pattern of CD44 (standard and variants) in the various forms of basal cell carcinoma. Our finding that the level of CD44 expression was closely related to the tumor growth pattern (and especially elevated in the thinnest, apparently invasive tumor strands) was greatly facilitated by the application of a simplified classification of basal cell carcinoma. The implications for the interaction of the tumor cells with the extracellular matrix and inflammatory cells are briefly discussed.