SHORT COMMUNICATION: Inhibition of gap junctional intercellular communication and delocalization of the cell adhesion molecule E-cadherin by tumor promoters (original) (raw)

The effect of 12-0-tetradecanoylphorbol-13-acetate (TPA) and benzoyl peroxide (BoP) on gap junctional intercellular communication (GJIC) and the amount and localization of E-cadherin was studied in initiated mouse epidermal cells (3PC) and in carcinoma cells (CA3/7) originating from the same cell type. In addition, the localization and phosphorylation of connexin43 was studied in both cell h'nes and in primary keratinocytes. GJIC inhibition by TPA and BoP was stronger in primary keratinocytes compared with both cell lines. BoP strongly decreased the amount of E-cadherin protein and the level occurring in the membranes in both cell lines, whereas TPA caused a translocation of E-cadherin from the membrane towards the cytosol, without decreasing the total amount of E-cadherin present. p The effect of both tumor promoters on connexin43 phosphorylation and localization was agent as well as cell c '