Bioinformatics analysis of the molecular mechanism of diffuse intrinsic pontine glioma

The present study aimed to elucidate key molecular mechanisms in the progression of diffuse intrinsic pontine glioma (DIPG). The gene expression profile GSE50021, which consisted of 35 pediatric DIPG samples and 10 normal brain samples, was downloaded from the Gene Expression Omnibus database. The differentially-expressed genes (DEGs) in the pediatric DIPG samples were identified. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome pathways of DEGs were enriched and analyzed. The protein-protein interaction (PPI) network of the DEGs was constructed and functional modules of the PPI network were disclosed using ClusterONE. A total of 679 DEGs (454 up- and 225 downregulated) were identified in the pediatric DIPG samples. DEGs were significantly enriched in various GO terms, and KEGG and Reactome pathways. The PPI network of upregulated (153 nodes and 298 connections) and downregulated (71 nodes and 124 connections) DEGs, and two crucial modules, were obtained. Downregulated genes in module 2, such as cholecystokinin (CCK), gastrin (GAST), adenylate cyclase 2 (brain) (ADCY2) and 5-hydroxytryptamine (serotonin) receptor 7 (HTR7), were significantly enriched in the calcium signaling pathway, the neuroactive ligand-receptor interaction pathway and in GO terms, such as the G-protein coupled receptor (GPCR) signaling pathway, while upregulated genes in module 1 were not enriched in any pathways or GO terms. CCK and GAST associated with the GPCR signaling pathway, HTR7 enriched in the neuroactive ligand-receptor interaction, and ADCY2 and HTR7 involved in the calcium signaling pathway may be key mechanisms playing crucial roles in the development and progression of DIPG.