INDUCTION OF PA2.26, A CELL-SURFACE ANTIGEN EXPRESSED BY ACTIVE FIBROBLASTS, IN MOUSE EPIDERMAL-KERATINOCYTES DURING CARCINOGENESIS

The monoclonal antibody PA2.26, produced against mouse epidermal kerat inocytes transformed with 7,12-dimethylbenz[a]anthracene (DMBA), recog nizes a 43- to 47-kDa cell-surface protein that was absent from nontum origenic epidermal keratinocytes but present in transformed epidermal cell lines as well as cultured normal fibroblasts. In vivo, the antige n was absent from normal epidermis but induced in basal-like epidermal keratinocytes and dermal fibroblasts during tissue regeneration after wounding and treatment with the tumor promoter 12-O-tetradecanoylphor bol-13-acetate (TPA). The PA2.26 protein was also expressed in basal-l ike cells of differentiated papillomas and carcinomas generated in mic e treated with DMBA and TPA. In addition, the antigen was abundantly s ynthesized by stromal cells of the tumors. These results suggest that PA2.26 antigen is involved in reactive processes during skin remodelin g and carcinogenesis. (C) 1997 Wiley-Liss, Inc.