Biological function analysis of differentially expressed genes of primary glioblastomas of isocitrate dehydrogenase 1 mutation

Abstract

Objective To investigate the biological function of differentially expressed genes of primary glioblastomas of isocitrate dehydrogenase 1 (IDH1) mutation. Methods A total of 69 patients with primary glioblastoma from Chinese Glioma Genome Atlas who received surgical resection and then received radiotherapy and alkylating chemotherapy between January 2005 and December 2009 were collected. After the extraction of tissue RNA, the whole genome microarray analysis was performed; after the extraction of tissue DNA, pyrosequencing was performed in order to detect the status of IDH1 gene mutation. The tissue samples were divided into either an IDH1 gene mutation type or an IDH1 wild type according to whether there was a point mutation or not. The RNA expression profile data of the samples were analyzed by using the BRB Array Tools. The differentially expressed genes were obtained between the 2 groups. Omics analysis software OmicsBean was used to conduct the biological function annotation and protein-protein interaction network analysis for differentially expressed genes of mutant wild-type IDH1 in two groups of cases. Results In the 2 groups of samples of the IDH1 gene mutation type and the IDH1 wild type, there were significant differences in a total of 525 gene expressions. The 148 genes up-regulated in the expression level in the IDH1 gene mutation type primary glioblastomas mainly reflected the alterations of energy metabolism and protein metabolism after IDH1 mutation (such as tricarboxylic acid cycle and multiple amino acid metabolism), whereas the 377 genes down-regulated in the expression level were mainly involved in the cell adhesion, the interaction of extracellular matrix and receptors and other biological processes. Conclusion IDH1 mutation caused the changes in biological processes including energy metabolism, protein metabolism, and the expression levels of some cancer-related genes in gliomas. Key words: Glioblastoma; Isocitrate dehydrogenase; Gene expression; Mutation; Biological processes; Protein interaction network