EXPRESSION OF CD44 STANDARD AND VARIANT FORMS IN SKIN TUMORS - LOSS OF CD44 CORRELATES WITH AGGRESSIVE POTENTIAL

CD44 is an ubiquitous surface molecule that exists as a number of isoforms generated by alternative splicing of ten variant exons. Variant forms are upregulated in vitro upon treatment with cytokines and have been reported to be involved in neoplastic transformation and tumor progression in rat and human tissue. We have analysed hyperproliferative disorders and a large number of primary skin tumors and metastases by Immunohistochemistry for the expression of CD44 isoforms containing exons 4v, 6v or 9v. Upregulation of all isoforms accompanied hyperproliferative disorders. Conversely, clown-regulation of CD44 molecules expression was observed in primary skin tumors and metastases.