Detection of miRNA Expression Alteration in Diffuse and High Grade Glial Tumors

Summary Objective: It was aimed to determine the expression profiles of miRNAs in patients with diffuse and anaplastic brain tumors. Methods: miRNA expression profiles of 50 cases (19 Female, 31 Male) diagnosed with brain tumor [32 Glioblastoma (GBM), 10 diffuse astrocytoma (DA), 8 anaplastic oligodendroglioma (AO)] in Ege University, Department of Neurosurgery and of brain tumor cell lines (U-87 MG, U-118 MG and LN18) studied by the microarray method. Results: In all cases miR-21 expression level was high and no miR-124 expression was detected. In GBM, miR-495 and miR-432 expression showed significant 2-fold increase, and miR-708-3p, mir-339-5p and miR-4286 expressions 4-fold, mir-331-3p, miR-625-3p, and miR-20a-3p showed 5-fold reduction compared to cell lines. miRNA expressions compared GBM and AO, it was detected that miR-34c-3p, miR-132-5p, mir-605, miR-3130-3p, miR3127, mir-517a-pre, mir-548b-3p, miR-921, miR-769-5p were significantly increased. mir204 expression was significantly decreased in AO compared to cell lines. In DA, miRNA expression was significantly increased in 18 and decreased in 7. There was no significant miRNA expression changes in AO compared with DA. miRNA expressions of DA, AO and GBM cases were compared and significant alterations were found in 29 miRNA expressions. Conclusion: miRNA expression profiles of GBM were significantly different from AO. It was emphasized that, new genes could be effective in tumor development supposed to be regulated by miRNAs. New specific gene targets regulated by miRNA expression could be predicted good clinical outcome in brain tumors.