Lead Optimization of Androgen Receptor-HSP27 Disrupting Agents in Glioblastoma

Glioblastoma (GBM) is the most common malignant brain tumor with poor prognosis under the current standard treatment. It is critical to develop new approaches to selectively battle the disease. GBM sex differences suggest that an androgen receptor (AR) is a potential therapeutic target to treat AR-overexpressed GBM. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein that stabilizes AR. Inhibition of HSP27 leads to AR degradation, indicating that HSP27 inhibitors could suppress AR activity in GBM. We have identified a lead HSP27 inhibitor that could induce AR degradation. Lead optimization resulted with two new derivatives (compounds <b>4</b> and <b>26</b>) showing potent anti-GBM activity and improved drug distribution in comparison to the lead compound. Compounds <b>4</b> and <b>6</b> exhibit IC₅₀s of 35 and 23 nM, respectively, to inhibit cell proliferation and also show significant activity to decrease the tumor growth <i>in vivo</i>.