Epidermal growth factor receptor (EGFR)-activating mutations are established biomarkers of resistance to immune checkpoint blockade (ICB) in lung cancer, yet the precise molecular mechanism and effective therapeutic strategies remain elusive. In this study, we show that EGFR overexpression and amplification recapitulate the negative impact of EGFR driver mutations to ICB response, indicating a proactive involvement of EGFR signaling in antagonizing antitumor immune response. Functional studies unveil that EGFR activation suppresses cellular response to interferon-gamma (IFN-γ) following ICB treatment across multiple cancer models. This impairment in IFN-γ responsiveness further limits the upregulation of T cell-recruiting chemokines and antigen presentation, resulting in reduced T cell infiltration and activation, ultimately undermining antitumor immunity. Mechanistically, EGFR promotes SHP2 activation to accelerate STAT1 dephosphorylation, leading to premature termination of the IFN-γ response. SHP2 inhibition restored ICB sensitivity in EGFR-activated tumors, significantly reducing tumor burden while maintaining a favorable safety profile. Our findings suggest that EGFR/SHP2 axis functions as a molecular brake to disrupt the initiation and amplification of IFN-γ mediated anti-tumor response during immunotherapy. This discovery unveils a potential avenue to overcome immunotherapy resistance in EGFR-driven tumors, particularly lung cancer, through SHP2-targeted combination strategies.
Keywords: Cancer immunotherapy; Immunology; Lung cancer; Oncogenes; Oncology.