MAP2K1 K57E

Of the entire cohort, we observed five activating PIK3CA mutations (R108H; G364R; E542K; E545K, n = 2) which may be sensitive to FDA-approved PIK3CA inhibitor alpelisib. Additionally, patients with loss-of-function mutation in NF1 (n = 2), STK11 (n = 1) and PTEN (n = 1) can be targeted with MEK inhibitor selumetinib and mTOR inhibitor everolimus, respectively. Except for one V600E mutation, all mutations in BRAF are either type 2 (L597R, n = 1) or type 3 (N581S, n = 1; D594N, n = 4) which were sensitive to MEK inhibitor trametinib...Interestingly, one IDH1 mutation (R132C) carrier in our cohort might benefit from ivosidenib... Through comprehensive genomic characterization of Chinese SBA patients, we identified actionable variants of multiple signaling pathways in plenty. NGS profiling results can guide physicians to enroll a significant portion of SBA patients in genomically-matched clinical trials.

We also found two MAP2K1 activating mutations (K57E and K57N) which can be targeted by trametinib...We also observed two activating PIK3CA mutations (R108H and G364R) which may be sensitive to PIK3CA inhibitor alpelisib... The mutational landscape of our SBA cohort provided compelling evidence that multiple signaling pathways play a role in the pathogenesis of SBA and many driver mutations in these pathways are targetable. Our findings indicated that SBA patients should participate in matched clinical trials for better management of this disease.

This study revealed multiple genetic, proteomic and phosphoproteomic alterations associated with erlotinib resistant SCC-R cells. Our data indicates that therapeutic targeting of MAPK pathway is an effective strategy for treating erlotinib-resistant HNSCC tumors.