Estrone Sulfatase Inhibitors as New Anticancer Agents

Enzyme steroid sulfatase (STS) is considered as a promising therapeutic target for the treatment of hormone-dependent oncological diseases such as breast, endometrial, prostate cancers, and endometriosis. The discovery of potent and irreversible STS inhibitors stimulated huge efforts of preclinical and clinical work. Various STS inhibitors such as steroid sulfamate, steroid nonsulfamate, nonsteroidal sulfamate, and nonsteroidal nonsulfamate-based inhibitors have been developed. In the review known STS inhibitors from the point of view of their safety, side-effects and perspectives for clinical application are considered. Among STS inhibitors several dual (multitargeted) compounds have huge potential being nonestrogenic and acting in nanomolar levels on the targets. The dual aromatase-sulfatase inhibitors (DASI) approach has a great potential when a synergy between STS and aromatase inhibition is expected and, thus it could address acquired resistance mechanisms. Among STS inhibitors based on steroid skeleton 17α-benzyl-, 17β-arylsulfonamides, 17-diisopropylcarbamoyl-3-O-sulfamates exhibit the best properties, especially as dual anticancer potential drugs. The same modifications result in the increased activity against STS in 2-OMe-3-O-sulfamates as well as 2-OMe-3, 17β-bissulfamates, which are also active against triple negative breast cancer. 8α-Steroid estrogen analogs without estrogenic properties also possess high STS-inhibitory activity and block breast cancer cells growth with the activity comparable to tamoxifen