DRUG-RESISTANCE ASSOCIATED ALTERATIONS OF CELL-SURFACE ANTIGEN EXPRESSION IN A HUMAN ANTHRACYCLINE-RESISTANT OVARIAN-CARCINOMA CELL-LINE

The anthracycline uptake and cell surface expression of plasma membran e antigens (HLA class I, c-erbB-2, protectin CD59, integrin beta(1)-ch ain - CD29, etc.) were compared on a parental anthracycline sensitive and an anthracycline resistant subline of the human ovarian carcinoma cell line A2780. The anthracycline-resistant (A2780/ADR) subline incub ated for 30 min in the presence of daunomycine displayed two subpopula tions with different anthracycline cell content as determined by now c ytometry. The subpopulation with lower daunomycin cell content was abs ent in the parental anthracycline sensitive cell line. The most predom inant antigenic changes on the resistant subline as compared with the sensitive one were as follow: Loss of HLA class I and a twofold increa se in the expression of CD59 antigen and a slight decrease of integrin Pi-chain on the cell surface of the resistant subline.