Proteomic and metabolomic dissection of the <i>BRAF</i> V600E mutation-induced cellular state transition in lung epithelial cells

Non-small cell lung cancer (NSCLC) is the most common subtype of lung cancer, and 4% of NSCLC patients are reported to harbor mutations in <i>BRAF</i>, which encodes a serine/threonine kinase capable of activating the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. However, the role and effects of <i>BRAF</i> mutation in NSCLC or lung lineage cells are not fully understood. To mimic the naturally occurring <i>BRAF</i> V600E mutation in lung cancer, a <i>BRAF</i> V600E knock-in BEAS-2B cell model was established using CRISPR/Cas9. Although the <i>BRAF</i> V600E mutation alone was not sufficient to drive lung carcinogenesis, it induced remarkable changes in cellular migration capacity and tumorigenic potential. Proteomics analysis revealed significant changes in the proteins involved in the biological processes including epithelial-mesenchymal transition (EMT), extracellular matrix (ECM)-receptor interaction, cell adhesion, focal adhesion, and cell metabolism upon the <i>BRAF</i> V600E mutation. Untargeted metabolomics experiments revealed that amino acid metabolism, especially glycine, serine and threonine metabolism, was significantly modulated in <i>BRAF</i> V600E knock-in cells. In summary, this study provides a new isogenic cell model that allows us to systematically dissect the underlying molecular events involved in the transition of cellular states upon the introduction of the <i>BRAF</i> V600E mutation.