Secosteroid diacylhydrazines as novel effective agents against hormone-dependent breast cancer cells

This research aimed to develop novel selective secosteroids that are highly active against hormone-dependent breast cancer. A simple and convenient approach to N′-acylated 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides was disclosed and these novel types of secosteroids were screened for cytotoxicity against the hormone-dependent human breast cancer cell line MCF7. Most secosteroid N′-benzoyl hydrazides have demonstrated high cytotoxicity against MCF7 cells with IC₅₀ values below 5 μM, which are superior to that of the reference drug cisplatin. Hit compounds 2c, 2e and 2i were characterized by high cytotoxicity (IC₅₀ = 1.6–1.9 μM) and very good selectivity towards MCF7 breast cancer cells. The lead secosteroids 2c, 2e and 2i also exhibit antiestrogenic effects and alter the expression of cell cycle regulating proteins. The effect of selected compounds on PARP (poly(ADP-ribose) polymerase) and Bcl-2 (B-cell CLL/lymphoma 2) indicates their proapoptotic potential. The synthesized secosteroids may be considered as new promising anti-breast cancer agents targeting ERα and apoptosis pathways.