Cell-Based Drug Discovery: Identification and Optimization of Small Molecules that Reduce -MYC Protein Levels in Cells.

Elevated expression of the -MYC oncogene is one of the most common abnormalities in human cancers. Unfortunately, efforts to identify pharmacological inhibitors that directly target MYC have not yet yielded a drug-like molecule due to the lack of any known small molecule binding pocket in the protein, which could be exploited to disrupt MYC function. We have recently described a strategy to target MYC indirectly, where a screening effort designed to identify compounds that can rapidly decrease endogenous -MYC protein levels in a amplified cell line led to the discovery of a compound series that phenocopies -MYC knockdown by siRNA. Herein, we describe our medicinal chemistry program that led to the discovery of potent, orally bioavailable -MYC-reducing compounds. The development of a minimum pharmacophore model based on empirical structure activity relationship as well as the property-based approach used to modulate pharmacokinetics properties will be highlighted.