Molecular analysis of oncogene expressions in different grades of gliomas

The aggressiveness of brain tumors is attributed to the expression of multiple oncogenes involved in proliferation, metabolism and therapeutic resistance whose potential correlation with tumor progression has not been well-studied. In this study, we aimed to investigate the relationship of oncotargets involved in pathogenesis with respect to glioma grades. Gliomas (n=40) were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing for the detection of epidermal growth factor receptor (EGFR) mutants. Expressions levels of EGFR, EGFR variant III (EGFRvIII), Lck/Yes novel tyrosine kinase (LYN), Spleen tyrosine kinase (SYK), insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K), Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP1) and glucose transporter 3 (GLUT3) were studied using real-time PCR and compared against glioma grades via statistical methods. Protein expressions were analyzed using immunohistochemistry and western blotting. EGFRvIII was detected in 53% and exon 4 deletion (de4 EGFR) in 20% of gliomas. Importantly, the expressions levels of candidate oncogenes were significantly upregulated (