Study on the Genetic Links Between Type 2 Diabetes Mellitus and Glioma by Bioinformatics

Diabetes will increase the risk of most cancers, such as pancreatic, breast and prostate cancer. However, some studies showed patients with diabetes are less susceptible to glioma than the people with normal blood sugar. This inverse relationship between diabetes and glioma remained elusive. Here, we aimed to use bioinformatics methods to reveal the underlying molecule mechanisms between diabetes and glioma. We obtained the gene expression profiles of diabetes (GSE25724) from GEO database. Obtained gene expression profiles of glioma and normal brain tissue from TCGA and GTEX databases. Nine differentially expressed genes (HSPE1-MOB4, BMP5, CD99, MAFB, PLP2, CTSC, NAMPT, VIM, IL13RA2) with opposite expression changes were identified in 2 diseases. These genes were down-regulated in diabetes, but up-regulated in glioma. We then conducted an integrated analysis of these genes, including protein–protein interaction (PPI) network, Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. We validated the expression of hub genes in external datasets (GSE7014 and GSE4290) and studied the correlation between hub genes.