Ellipticine derivatives with an affinity to the estrogen receptor. An approach to develop intercalating drugs with a specific effect on the hormone-dependent breast cancer

In order to obtain breast tumor directed agents, we have prepared mixed compounds using estradiol or (E)-clomiphene as specific vectors of the breast tissue and a DNA intercalator from the ellipticine series as the cytotoxic agent. Among the newly synthesized ellipticine derivatives, only the 2-[3-aza-5-(3,17 beta-dihydroxy-1,3,5-estratrien-17 alpha-yl)-4-oxopentamethylene]ellipticinium bromide shows the desired properties, DNA intercalation and affinity for estrogen receptor. Competition experiments with estradiol on the hormone-dependent human MCF-7 breast cancer cell line demonstrate that a transport by the estrogen receptor system is not involved in the antitumor activity of derivative 24.