CDw60, which identifies the acetylated form of GD3 gangliosides, is strongly expressed in human basal cell carcinoma

The monoclonal antibody UM4D4, assigned to the CDw60 cluster of differentiation, identities an epilope expressed on a subset of normal T cells, some malignant T cells, melanocytes, malignant melanoma cells and hyperproliferative psoriatic keratinocytes. CDw60 antibodies bind to the acetylated form of G_D3 gangliosides. These gangliosides have been implicated in the control of cellular proliferation. Because the acetylated form of G_D3 has been demonstrated in basal cell carcinomas, we determined whether the CDw60 epitope was expressed in basal cell carcinomas (n= 24) and squamous cell carcinomas (n= 2). Biopsies of these tumours 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 contrasl, CDw60 expression in normal skin was confined to melanocytes and a few scattered keratinocytes at the basal cell layer. CDw60 expression in basal cell carcinomas was highly upregulated at the tumour front in most of the lesions, whereas the squamous cell carcinomas showed uniform CDw60 expression in all areas.