Inhibition of 125I-epidermal growth factor binding to murine fibroblasts and keratinocytes by irradiation with ultraviolet-B light

Brooks, G., Goss, M.W. and Hart, I.R. (1990) Inhibition of 125I-epidermal growth factor binding to murine fibroblasts and keratinocytes by irradiation with ultraviolet-B light. Carcinogenesis, 11 (7). pp. 1223-1227. ISSN 0143-3334 doi: 10.1093/carcin/11.7.1223

Abstract/Summary

Treatment of murine Swiss 3T3 fibroblasts and XB/2 keratinocytes with UV-B light (302 nm) resulted in a dose-dependent inhibition of [125I] epidermal growth factor (EGF) binding. The light dose required to achieve 50% inhibition of binding in both cell types was 80–85 J/m2 Decreased [125I] platelet-derived growth factor binding was not evoked even by light doses of up to 280 J/m2 UV-B irradiation did not stimultate phosphorylation of the 80 kd protein substrate for protein kinase C. Furthermore, its effect on [125I]EGF binding was not altered as a consequence of protein kinase C down-regulation following prolonged exposure of cells to phorbol esters. These results indicate that UV-B-induced transmodulation of the epidermal growth factor receptor is a specific event mediated through a protein kinase C-indepen dent pathway. Transfer of culture medium from irradiated cells to untreated control cells showed this effect was not induced as a result of transforming growth factor α release and subsequent binding to the EGF receptor in these cells.