Proteogenomic Characterization Reveals Estrogen Signaling as a Target for Never-Smoker Lung Adenocarcinoma Patients without EGFR or ALK Alterations [RNA-seq]

Never-smoker lung adenocarcinoma (NSLA) is prevalent in Asian populations, and is even more in women. EGFR mutations and ALK fusions are major alterations observed in NSLA. We have focused on NSLA without EGFR and ALK alteration (NENA) rather than NSLA with EGFR and ALK (EA). First, we selected 141 NSLA tissues, and performed proteogenomic analyses including the whole-genome sequencing (WGS), transcriptome, methylation EPIC array, total proteome and phosphoproteome. We then excluded 40 patients with EA and 7 patients with NENA microsatellite instability. Genome analysis revealed that TP53 (25%), KRAS (22%), ROS1 fusion (14%), and SETD2 (11%) were the most frequently mutated genes in NENA patients. Proteogenomic impact analysis revealed that STK11 and ERBB2 somatic mutations had broader effects on cancer-associated genes in NENA. Through DNA copy-number alteration analysis, we identified 22 prognostic proteins, influencing transcriptomic and proteomic changes. Gene set enrichment analysis revealed that the estrogen signaling emerged as the key pathway activated in NENA. A lot of proteogenomic evidence supported the increased estrogen signaling, such as copy-number deletions in chromosomes 14 and 21, STK11 mutation, and DNA hypomethylation of LLGL2 and ST14. Finally, saracatinib, an Src inhibitor, was suggested as a potential drug for targeting activated estrogen signaling in NENA, and was experimentally validated in vitro using cell line model. In this study, we enhanced our understanding of the etiology of NENA NSLA through the proteogenomic landscape, based on which we proposed saracatinib as an effective drug