CDW60, WHICH IDENTIFIES THE ACETYLATED FORM OF G(D3) GANGLIOSIDES, ISSTRONGLY EXPRESSED IN HUMAN BASAL-CELL CARCINOMA

The monoclonal antibody UM4D4, assigned to the CDw60 duster of differe ntiation, identifies an epitope expressed on a subset of normal T cell s, some malignant T cells, melanocytes, malignant melanoma cells and h yperproliferative psoriatic keratinocytes, CDw60 antibodies bind to th e acetylated form of G(D3) gangliosides, These gangliosides have been implicated in the control of cellular proliferation. Because the acety lated form of G(D3) has been demonstrated in basal cell carcinomas, we determined whether the CDw60 epitope was expressed in basal cell carc inomas (n=24) and squamous cell carcinomas (n=2). Biopsies of these tu mours were sectioned on a cryostat, and stained with anti-CDw60 using a sensitive indirect immunoperoxidase technique. A mean of 74 +/- 4% ( mean +/- SEM) of the basal cell carcinoma cells expressed CDw60, In co ntrast, CDw60 expression in normal skin was confined to melanocytes an d a few scattered keratinocytes at the basal cell layer. CDw60 express ion in basal cell carcinomas was highly upregulated at the tumour fron t in most of the lesions, whereas the squamous cell carcinomas showed uniform CDw60 expression in all areas.