EGFR and EGFRvIII coopt host defense pathways, promoting progression in glioblastoma

Co-amplification of EGFR and EGFRvIII, a tumor-specific truncation mutant of EGFR, represent hallmark genetic lesions in glioblastoma. We report that EGFR and EGFRvIII stimulate the innate immune defense receptor Toll-like Receptor 2 (TLR2); and that knockdown of TLR2 led to a dramatic survival advantage in glioblastoma xenografts. EGFR and EGFRvIII activated TLR2 in a ligand-independent manner, promoting tumor growth and immune evasion. We show that EGFR and EGFRvIII cooperate to activate the Rho-associated protein kinase ROCK2, modulating malignant progression both by activating TLR2 and WNT signaling, and through remodeling the tumor microenvironment.