ANTIPROLIFERATIVE ACTIVITY OF A SERIES OF NOVEL CYCLOPROPYL ANTIESTROGENS ON MCF-7 HUMAN BREAST-CANCER CELLS IN CULTURE

The potential antitumor activity of a series of novel cyclopropyl compounds, which lack estrogen agonist activity, was evaluated in estogen receptor positive human breast cancer cells (MCF-7) in culture. The compounds were evaluated to determine their antiproliferative activity at a concentration of 1-mu-M at 2, 4 and 6 days of treatment by hemocytometer using the Trypan Blue exclusion method to count viable cells. Estradiol-induced reversibility of the antiproliferative activity of these compounds was also evaluated. The activity of a series of 19 diaryl- and triarylcyclopropyl compounds was examined. Thirteen compounds inhibited the growth of MCF-7 cells while six were inactive. Five of the 13 active compounds produced antiproliferative activity which was reversed by 0.1-mu-M estradiol. Thus, several of these novel cyclopropyl compounds may be useful in the treatment of hormone-dependent breast cancer and other estrogen-dependent tumors.