A Comprehensive Bioinformatic Analysis Based on Functional Studies of MEF-2 Family in NSCLC

Lung cancer remains the malignancy with the highest morbidity and mortality worldwide. There are no effective guiding therapies and prognosis biomarkers, and the overall prognosis of lung cancer remains poor. The cardiomyocyte enhancer factor 2 (MEF-2) family is a highly evolutionarily conserved transcription factor that plays important roles in a variety of diseases, including tumors. Still, the overall bioinformatics function of the MEF-2 gene family in non-small cell lung cancer (NSCLC) has not been systematically reported yet. MEF-2 family members have low expression in NSCLC tissues and are associated with clinicopathological stages. MEF-2B/2D is highly expressed in lung metastatic tissues. MEF-2A, MEF-2B, and MEF-2D have obvious advantages in the diagnosis of NSCLC. Survival analysis of lung adenocarcinoma (LUAD) patients in the Cancer Genome Atlas (TCGA) database shows that MEF-2C is strongly associated with poor overall survival (OS) and disease-specific survival (DSS). Univariate and multivariate Cox analyses demonstrated that MEF-2A independently predicts the progression-free interval (PFI) in NSCLC patients. Gene set enrichment analysis (GSEA) showed that MEF-2 family members are associated with immune cell receptor function and regulation of immunoglobulin complexes. The differentially expressed genes (DEGs) associated with MEF-2 family members were significantly enriched in the cAMP signaling pathway and gastric acid secretion. Gene ontology (GO) analysis revealed DEGs that play critical roles in the cytochrome-c oxidase activity, electron transfer activity, oxidoreduction-driven active transmembrane transporter activity; the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis shows that they are mainly enriched in oxidative phosphorylation, thermogenesis, and diabetic cardiomyopathy. MEF-2A is a potential diagnostic, prognostic biomarker, and promising therapeutic target for NSCLC. Further studies are needed to verify and clarify the underlying mechanisms.