A sterol analog inhibits hedgehog pathway by blocking cholesterylation of smoothened.

The hedgehog (Hh) signaling pathway has long been a hotspot for anti-cancer drug development due to its important role in cell proliferation and tumorigenesis. However, most clinically available Hh pathway inhibitors target the seven-transmembrane region (7TM) of smoothened (SMO), and the acquired drug resistance is an urgent problem in SMO inhibitory therapy. Here, we identify a sterol analog Q29 and show that it can inhibit the Hh pathway through binding to the cysteine-rich domain (CRD) of SMO and blocking its cholesterylation. Q29 suppresses Hh signaling-dependent cell proliferation and arrests Hh-dependent medulloblastoma growth. Q29 exhibits an additive inhibitory effect on medulloblastoma with vismodegib, a clinically used SMO-7TM inhibitor for treating basal cell carcinoma (BCC). Importantly, Q29 overcomes resistance caused by SMO mutants against SMO-7TM inhibitors and inhibits the activity of SMO oncogenic variants. Our work demonstrates that the SMO-CRD inhibitor can be a new way to treat Hh pathway-driven cancers. [Display omitted] • Q29 is a sterol analog that suppresses the hedgehog (Hh) signaling • Q29 blocks the cholesterylation of cysteine-rich domain (CRD) of smoothened (SMO) • Q29 inhibits Hh-dependent medulloblastoma growth and synergizes with vismodegib • Q29 inhibits the drug-resistant and oncogenic SMO variants Liu et al. identify a sterol analog Q29 and show that it can inhibit the hedgehog (Hh) pathway through blocking the cholesterylation of the cysteine-rich domain (CRD) of smoothened (SMO). Q29 is able to overcome drug resistance associated with SMO-7TM inhibitors and inhibit the growth of Hh-dependent tumors. [ABSTRACT FROM AUTHOR]