Pan-cancer analysis supports MAPK12 as a potential prognostic and immunotherapeutic target in multiple tumor types, including in THCA

P38 mitogen-activated protein kinase (MAPK)12 (also known as P38 γ) is critical in the development and progression of various types of tumors. Despite the extensive literature on the subject, further studies are needed to elucidate its role in cancer progression. Here, a comprehensive bioinformatics analysis of a generalized cancer dataset was performed to explore the mechanism of MAPK12 regulation in tumorigenesis. Several tumor datasets and online analytical tools, including HPA, SangerBox, UALCAN, GEPIA2, STRING, ImmuCellAI, and MEXPRESS, were used to analyze the expression information on MAPK12 in several types of cancers. Western blotting and reverse transcription-quantitative PCR were used to verify the protein and mRNA expression levels of MAPK12, respectively, in human normal thyroid cells (HTORI-3) and thyroid carcinoma (THCA) cells. Cytotoxicity and EdU assays were used to verify the promoting effect of MAPK12 on cell proliferation in THCA cells. Analysis of several cancers found that MAPK12 was overexpressed in multiple cancer types. Upregulated MAPK12 mRNA expression levels were correlated with a worse prognosis in patients with several types of cancer. Cytotoxicity and EdU experiments showed that MAPK12 knockdown inhibited THCA cell proliferation. Gene Ontology-Biological Process and Kyoto Encyclopedia of Genes and Genomes analyses showed that the enrichment of MAPK12 genes was related to cell proliferation and the tumor immune microenvironment. These results showed that MAPK12 was closely related to the immune checkpoint, microsatellite instability, and tumor mutational burden and affected the sensitivity of the tumor to immunotherapy. This study showed that MAPK12 may be an immunotherapeutic and promising prognostic biomarker in certain types of tumors.