ABL Kinases Modulate EZH2 Phosphorylation and Signaling in Metastatic Triple Negative Breast Cancer

Area of Science:

• Oncology
• Molecular Biology
• Epigenetics

Background:

• Triple-negative breast cancer (TNBC) is aggressive with poor outcomes.
• Epigenetic regulators are implicated in TNBC metastasis.
• ABL kinases are known to promote breast cancer metastasis.

Purpose of the Study:

• To explore the role of ABL kinases in epigenetic regulation in TNBC metastasis.
• To investigate the functional link between ABL kinases and the PRC2 complex.
• To identify novel therapeutic strategies for TNBC.

Main Methods:

• Inactivation of ABL kinases in bone metastatic TNBC cells.
• Analysis of gene signatures associated with the PRC2 complex.
• Investigating the FAK-CDK1 signaling axis and EZH2 phosphorylation.
• Assessing combination therapy with ABL and EZH2 inhibitors in vitro and in vivo mouse models.

Main Results:

• ABL kinase inactivation enriches for PRC2 complex gene signatures in TNBC cells.
• ABL inactivation promotes EZH2-T487 phosphorylation via FAK-CDK1 signaling.
• Phosphorylated EZH2 exhibits altered binding to c-MYC and ZMYND8.
• Combination ABL and EZH2 inhibition synergistically reduces TNBC cell survival and metastasis.

Conclusions:

• ABL kinases regulate epigenetic processes, including PRC2 activity, in TNBC metastasis.
• Targeting the ABL-EZH2 axis presents a potential therapeutic strategy for TNBC.
• Combination therapy with ABL and EZH2 inhibitors demonstrates significant anti-metastatic effects and improved survival in preclinical models.