Effect of cytotoxic prostaglandin, delta 12-prostaglandin J2 on E-cadherin expression in transformed epidermal cells in culture

The cyclopentenone prostaglandins (PGs), such as delta 12-PGJ2 and PGA1, are potent inhibitors of growth in a variety of cultured cells, including human epidermal cells. To clarify the mechanism of the cytotoxicity of these PGs, we examined the effects of delta 12-PGJ2 on the function and expression of E-cadherin, which plays a major role in the maintenance of intercellular adhesion, in transformed human epidermal cells in culture (HSC-1). A 12-h incubation with 5 micrograms/ml of delta 12-PGJ2 did not affect the cell-binding activity of E-cadherin expressed in HSC-1 cells. Immunoblot analysis using a monoclonal antibody specific to human E-cadherin revealed that a 12-h incubation with 5 micrograms/ml of delta 12-PGJ2 induced E-cadherin expression in HSC-1 cells. Immunofluorescence using a monoclonal antibody against human E-cadherin demonstrated that E-cadherin was localized to the cell-cell contact regions in HSC-1 cells. Following a 12-h incubation with 5 micrograms/ml of delta 12-PGJ2, E-cadherin was also detected in a uniform pattern along cell junctions, although cell morphology was changed by the presence of cytotoxic PGs. These results suggest that the cytotoxicity of cyclopentenone PGs is related, at least in part, to E-cadherin expression in transformed human epidermal cells.