Hijacking a key chromatin modulator creates epigenetic vulnerability for MYC-driven cancer

Area of Science:

• Epigenetics
• Cancer Biology
• Molecular Oncology

Background:

• MYC protein's genomic binding correlates with active chromatin marks, but its tumorigenic potential is poorly understood.
• The functional impact of major epigenetic mechanisms on MYC's oncogenic activity requires further elucidation.

Purpose of the Study:

• To investigate the role of epigenetic mechanisms, specifically H3K4 methylation complexes, in MYC-driven tumorigenesis.
• To determine if core subunits of H3K4 methyltransferase complexes are implicated in MYC's oncogenic functions.

Main Methods:

• Analysis of DPY30 and other core subunits in human cancers and Burkitt lymphoma.
• Assessing DPY30's effect on MYC expression, MYC-DPY30 binding, and chromatin accessibility.
• Evaluating the impact of Dpy30 heterozygosity on Myc-driven lymphomagenesis and cellular transformation in animal models.

Main Results:

• DPY30, a core subunit of H3K4 methyltransferase complexes, is amplified in cancers and upregulated in Burkitt lymphoma.
• DPY30 promotes MYC expression and enhances MYC's genomic binding by regulating chromatin accessibility.
• Dpy30 deficiency suppresses Myc-driven lymphomagenesis and cellular transformation by impairing anti-apoptotic gene expression and increasing apoptosis.

Conclusions:

• MYC utilizes the H3K4 methylation pathway for target binding and oncogenic program coordination, creating an "epigenetic vulnerability."
• DPY30 and the H3K4 methylation pathway are potential therapeutic targets for MYC-driven cancers.