MELANOCYTES IN HUMAN SKIN EXPRESS BCL-2 PROTEIN

The bcl-2 gene was initially identified through its participation in t he translocation 14:18 in B-cell lymphomas;of follicular center cell o rigin. This classic translocation juxtaposes the transcriptionally act ive immunoglobulin heavy-chain locus on chromosome 14 to the bcl-2 gen e on chromosome 18, resulting in overexpression of bcl-2 protein. The oncogene bcl-2 is thought to prolong cell survival through interferenc e with programmed cell death. To date, bcl-2 expression has been repor ted in normal lymphoid, hemopoietic, neural, breast and prostatic tiss ues. Since melanocytes are neural crest derivatives and have an extend ed life-span, our objective was to determine whether the bcl-2 protein is expressed in human melanocytes. We analyzed normal skin biopsies f or bcl-2 expression using standard immunohistochemistry. As hypothesiz ed, dendritic cells in the basal epidermal layer stained strongly for bcl-2. The distribution and morphology of these cells was typical for melanocytes. Additionally, eccrine sweat glands, lymphocytes and the d ermal papilla of hair follicles demonstrated bcl-2 positivity. We beli eve this to be the first report of bcl-2 expression in normal melanocy tes. (C) Munksgaard 1994.