Combinatorial immunotherapies overcome MYC-driven immune evasion in triple negative breast cancer

Area of Science:

• Oncology
• Immunology
• Cancer Research

Background:

• Triple-negative breast cancer (TNBC) shows limited response to immune checkpoint inhibitors.
• The role of oncogenes, like MYC, in immunotherapy resistance and its reversibility is not well understood.

Purpose of the Study:

• To investigate if MYC expression in TNBC affects response to immune checkpoint inhibitors.
• To determine if MYC-driven immune evasion is reversible and can be therapeutically targeted.

Main Methods:

• Analysis of TNBC patient data and mouse models with varying MYC expression.
• Assessment of tumor immune infiltration, PD-L1, and MHC-I expression.
• Combination immunotherapy including TLR9 agonist, OX40 agonist, and anti-PD-L1.

Main Results:

• Elevated MYC expression in TNBC correlates with resistance to immune checkpoint inhibitors.
• MYC signaling reduces PD-L1 expression, immune cell infiltration, and MHC-I expression.
• Combination therapy led to tumor regression and protection against new tumor growth in mice.

Conclusions:

• MYC-driven immune evasion in TNBC is a reversible and targetable mechanism.
• Targeting MYC-dependent pathways alongside immune checkpoint inhibitors may enhance treatment efficacy for TNBC.