Orthogonal proteogenomic analysis identifies the druggable PA2G4-MYC axis in 3q26 AML

Area of Science:

• Hematology
• Molecular Biology
• Cancer Research

Background:

• Ecotropic viral integration site-1 (EVI1/MECOM) gene overexpression defines a lethal subgroup of acute myeloid leukemia (AML) with 3q26 abnormalities.
• Histone deacetylase inhibitors (HDACis) show potential for repressing EVI1, but their precise mechanism in 3q26 AML requires elucidation.

Purpose of the Study:

• To investigate the anti-leukemia mechanism of HDACis in 3q26 AML by dissecting EVI1 regulation.
• To identify key proteins interacting with EVI1 in the co-transcriptional complex and their role in HDACi response.

Main Methods:

• High-throughput cell-based and gene expression screening to identify EVI1 repressors.
• Analysis of bone marrow leukemia cell expression dynamics in patients treated with HDAC inhibitors.
• Reconstitution of the EVI1 chromatin-associated co-transcriptional complex, focusing on the proliferation-associated 2G4 (PA2G4) protein.

Main Results:

• PA2G4 overexpression confers resistance to HDACis in AML cells.
• Genetic and small molecule inhibition of PA2G4 effectively abrogates EVI1 expression in 3q26 AML cells and patient-derived xenografts.
• PA2G4 plays a critical role in mediating the EVI1 leukemogenic signal.

Conclusions:

• PA2G4 is a crucial mediator of the EVI1 oncogenic pathway in 3q26 AML.
• Targeting PA2G4 in combination with HDACis presents a promising therapeutic strategy for 3q26 AML.
• This research highlights PA2G4 as a potential therapeutic target for developing novel treatments for this aggressive AML subtype.