Targeted Disruption of Myc-Max Oncoprotein Complex by a Small Molecule

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Myc is crucial for cell growth and proliferation, and its dysregulation is common in human cancers.
• Currently, no targeted therapies exist to inhibit Myc activity.
• Myc's role in cancer necessitates the development of novel therapeutic strategies.

Purpose of the Study:

• To identify and characterize a novel small molecule inhibitor of Myc.
• To evaluate the efficacy of the inhibitor in preclinical cancer models.
• To elucidate the mechanism of action of the novel inhibitor.

Main Methods:

• High-throughput screening using PCA identified sAJM589.
• In vitro assays measured the disruption of the Myc-Max heterodimer.
• Transcriptome analysis (RNA-seq) assessed gene expression changes.
• Cell proliferation and anchorage-independent growth assays were performed.

Main Results:

• sAJM589 potently inhibits Myc-Max heterodimer formation (IC50 = 1.8 μM).
• sAJM589 preferentially inhibits Myc target gene transcription in Burkitt lymphoma cells.
• Genome-wide analysis revealed gene expression profiles similar to Myc depletion.
• sAJM589 suppressed proliferation and anchorage-independent growth in various cancer cell lines.
• The inhibitor reduced Myc protein levels, potentially via ubiquitination and degradation.

Conclusions:

• sAJM589 is a novel small molecule inhibitor of Myc.
• It effectively disrupts Myc-Max interaction and inhibits Myc-driven cancer cell growth.
• sAJM589 provides a potential basis for developing targeted therapies for Myc-dependent cancers.