Association of a STK11/KEAP1-mutation gene expression signature in lung adenocarcinoma with immune desertion in squamous cell carcinomas and mediation by NFE2L2 deregulation.

3082 Background: KEAP1 and STK11 mutations are associated with resistance to immune checkpoint inhibition (ICI) in non-small cell lung cancer (NSCLC). Mechanisms are currently unknown. Methods: We examined mutation, methylation, copy number and gene expression data from the cancer genome atlas (TCGA) lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LSCC), head and neck squamous cell carcinoma (HNSCC) and cervical carcinoma (CESC) data sets as well as public single cell gene expression data from a HNSCC cohort. Pathway annotations were performed using gene set enrichment analysis. A previously published cohort of NSCLC patients treated with ICI was analyzed for the predictive value of NFE2L2 mutations on PFS. Results: Annotation of STK11 and KEAP1 mutant LUAD revealed identical gene set enrichment for mitochondrial metabolism and downregulation of the STING-pathway, immune checkpoints, and interferon signaling. A STK11/KEAP1-mutation derived gene expression signature was established in LUAD and found to be driven by NFE2L2-regulated genes. This gene expression signature was independently predictive of immune desertion in LSCC, CESC and HNSCC and associated with STING-pathway downregulation in single cell sequencing analyses in HNSCC. KEAP1 and STK11 mutations were less frequent in LSCC, CESC and HNSCC but NFE2L2 mutations were identified in 15, 6 and 5%, respectively. NFE2L2 mutant SCC exhibited upregulation of the 15-gene- signature as well as immune desertion. In NSCLC, NFE2L2 mutations were associated with significantly worse PFS with ICI. Conclusions: Alterations of KEAP1, STK11, NFE2L2 and other related genes are linked to NFE2L2 target gene upregulation and immune desertion in LUAD, CESC, LSCC and HNSCC alike. The NFE2L2 pathway should be investigated clinically as a putative negative predictive biomarker for ICI and a potential therapeutic target.