Purpose: Activation of NFE2L2 has been linked to chemoresistance in cell line models. Recently, somatic mutations which activate NFE2L2, including mutations in NFE2L2,KEAP1, or CUL3,have been found to be associated with poor outcomes in patients with non-small cell lung cancer (NSCLC). However, the impact of these mutations on chemoresistance remains incompletely explored. Experimental Design: We investigated the effect of Keap1 deletion on chemoresistance in cell lines from Trp53-based mouse models of lung squamous cell carcinoma (LSCC) and lung adenocarcinoma (LUAD). Separately, we identified 51 stage IV NSCLC patients with KEAP1, NFE2L2, or CUL3 mutations and a matched cohort of 52 wildtype patients. Time to treatment failure after front line platinum doublet chemotherapy and overall survival was compared between the two groups. Results: Deletion of Keap1 in Trp53-null murine LUAD and LSCC resulted in increased clonogenic survival upon treatment with diverse cytotoxic chemotherapies. In NSCLC patients, median time to treatment failure (TTF) after first line chemotherapy for the KEAP1/NFE2L2/CUL3-mutant cohort was 2.8 months compared to 8.3 months in the control group (p < 0.0001). Median overall survival (OS) was 11.2 months in the KEAP1/NFE2L2/CUL3-mutant group and 36.8 months in the control group (p = 0.006). Conclusions: Keap1 deletion confers chemoresistance in murine lung cancer cells. Patients with metastatic NSCLC with mutations in KEAP1, NFE2L2, or CUL3 have shorter time to treatment failure and overall survival after first line platinum doublet chemotherapy compared with matched controls. Novel approaches for improving outcomes in this subset of NSCLC patients are therefore needed.
Keywords : Keap1, NRF2, non-small cell lung cancer, chemotherapy, chemoresistance