ASSESSMENT OF PCB ESTROGENICITY IN A HUMAN BREAST-CANCER CELL-LINE

Lower chlorinated, ortho substituted, non coplanar polychlorinated bip henyls (PCBs) are weakly estrogenic in rodents and in some in vitro as says. The estrogenic potency of six PCB congeners and one of their par a-hydroxylated metabolites have been tested in an estrogen-responsive MCF-7 human breast-cancer cell-culture system, to evaluate the utility of this system for assessment of PCB and hydroxylated PCB estrogenic activity. This assay is based on the estrogen receptor-mediated induct ion of postconfluent cell proliferation. The results of the limited te st series were generally consistent with, but not absolute in the requ irement for ortho-chlorine substitution and parahydroxylation for estr ogenic potency, demonstrating the usefulness of the MCF-7 focus assay for estrogenic structure-activity evaluation of PCBs. (C) 1997 Elsevie r Science Ltd.