Bozepinib: A Promising Selective Derivative Targeting Breast Cancer Stem Cells

Abstract

Bozepinib is a potent antitumour compound that shows an IC50 of 0.166 μM against MDA-MB-231 human breast cancer cell line. It is also a very selective drug that presents a therapeutic index (TI) of 11.0 against MDA-MB-231 in relation to the normal MCF-10A. It is important to identify new cancer stem-like cells (CSCs) anticancer drugs to struggle against the resistance and the high risk of relapse in patients. In the present chapter, we show how bozepinib demonstrated selectivity on cancer cells and showed an inhibitory effect over kinases involved in carcinogenesis, proliferation and angiogenesis. Bozepinib inhibits HER-2 signaling pathway and JNK and ERK kinases. In addition, it has an inhibitory effect on AKT and VEGF together with anti-angiogenic and anti-migratory activities. Interestingly, bozepinib suppresses the formation of both mammo- and colonospheres and eliminated ALDH+ CSC subpopulations at a low micromolar range similar to salinomycin. It also induces the downregulation of SOX2, c-MYC and β-CATENIN and upregulation of the GLI-3 Hedgehog signaling repressor. Finally, bozepinib shows in vivo antitumor and anti-metastatic efficacy in xenotransplanted nude mice without presenting subacute toxicity. However, further studies in cancer patients are needed to confirm the therapeutic potential of bozepinib.