MAP2K1/2 and MAP3K14 as a prognostic biomarker on immunotherapy and correlated with immune infiltrates in melanoma.

Abstract

e22104 Background: Mitogen-activated protein kinase kinase (also known as MAP2K, MEK, MAPKK) and MAP3K are two subgroup of Mitogen-activated protein kinase cascade. MAP2K1/2 and MAP3K14 are members of two subgroup, respectively. Previous study revealed that MAP2K1/2 and MAP3K14 may be a promising therapeutic target for melanoma. However, the association between MAP2K1/2 and MAP3K14 mutant and melanoma remains elusive. In this study, we aimed to elucidate the efficacy of immunotherapy of MAP2K1/2 and MAP3K14 mutant for melanoma by integrated bioinformatics analysis. Methods: Whole-exome sequencing data for a cohort of 110 patients with metastatic melanoma from whom pre-treatment tumor biopsies were download from cBioPortal. Associations between MAP2K1/2 and MAP3K14 mutations and prognosis and TMB are analyzed, and tumor-infiltrating level (TIL) of 18 T-cell subtypes and 6 other immune cells were used to investigate the underlying mechanism. Results: Results showed that MAP2K1/2 and MAP3K14 mutations were associated with an increased progression-free survival (PFS; HR, 0.42; 95% CI, 0.18-0.96; P = 0.0342) and a superior overall survival (OS; HR, 0.28; 95% CI, 0.09-0.90; P = 0.0227) in melanoma with significance at borderline level. TMB levels in melanoma patients with MAP2K1/2 and MAP3K14 mutations were higher than in wild-type patients (P = 0.007). Moreover, TIL revealed distinct immune cells features in the different groups, where immune cells related to infiltrating levels of Neutrophil cells and natural arising regulatory T (nTreg) cells were more prominently enriched in the mutation group while the wide-type group had higher enrichment of Mucosal associated invariant T (MAIT) cells and T helper 2 (Th2) cells. Conclusions: MAP2K1/2 and MAP3K14 mutations may be a potential predictor for better prognosis in melanoma on immunotherapy. Identification of MAP2K1/2 and MAP3K14 mutations by genomic profiling provides a potentially novel and convenient approach for these patients to predict the prognosis, and refines patient’s management in clinical practice.