Synthesis and evaluation of the antiproliferative activity of benzylidenes of 16-dehydroprogesterone series

•Synthesis benzylidenes of the 16-dehydroprogesterone.•Evaluation of antitumor activity against two breast cancer cell lines.•Compounds 3e,m,n regulate ERα signaling and reveal p53-independent mechanism of pro-apoptotic action in MCF-7 cells. Novel benzylidenes (chalcones) of the 16-dehydroprogesterone series have been characterized and their antitumor activity against two breast cancer cell lines was evaluated. Benzylidenes exhibit significant antiproliferative effect on cells and inhibit cell growth in hormone-dependent MCF-7 and hormone-independent MDA-MB-231 breast cancer cell lines. Compound 3d exhibits the highest activity against two breast cancer cell lines, with the IC50 value of about 2 µM. Compounds 3e,m,n display considerable selectivity for hormone-dependent breast cancer cells, with the IC50 value lower than 6 µM. Moreover, these steroidal benzylidenes regulate ERα signaling and reveal p53-independent mechanism of pro-apoptotic action in MCF-7 cells. The new class of antitumor compounds holds promise as the basis for the design of agents for cancer therapy.