Small-molecule inhibitors reveal multiple strategies for Hedgehog pathway blockade

Joel M Hyman, Ari J Firestone, Vivi M Heine, Yun Zhao, Cory A Ocasio, Kyuho Han, Mark Sun, Paul G Rack, Surajit Sinha, Jason J Wu, David E Solow-Cordero, Jin Jiang, David H Rowitch, James K Chen

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Inappropriate activation of the Hedgehog (Hh) signaling pathway has been implicated in a diverse spectrum of cancers, and its pharmacological blockade has emerged as an anti-tumor strategy. While nearly all known Hh pathway antagonists target the transmembrane protein Smoothened (Smo), small molecules that suppress downstream effectors could more comprehensively remediate Hh pathway-dependent tumors. We report here four Hh pathway antagonists that are epistatic to the nucleocytoplasmic regulator Suppressor of Fused [Su(fu)], including two that can inhibit Hh target gene expression induced by overexpression of the Gli transcription factors. Each inhibitor has a unique mechanism of action, and their phenotypes reveal that Gli processing, Gli activation, and primary cilia formation are pharmacologically targetable. We further establish the ability of certain compounds to block the proliferation of cerebellar granule neuron precursors expressing an oncogenic form of Smo, and we demonstrate that Hh pathway inhibitors can have tissue-specific activities. These antagonists therefore constitute a valuable set of chemical tools for interrogating downstream Hh signaling mechanisms and for developing chemotherapies against Hh pathway-related cancers.

Original languageEnglish
Pages (from-to)14132-7
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume106
Issue number33
DOIs
Publication statusPublished - 18 Aug 2009

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