Abstract 5256: MiRNA-31-5p expression in glioblastoma tissue and effects of its replacement in glioblastoma cells

Introduction: Glioblastoma multiforme (GBM) is the most malignant primary tumor of the central nervous system of adults. Our previous study has showed significant alterations in expression of microRNAs (miRNAs) in GBM tissue. Some of these miRNAs were also correlated with overall survival, whereas miR-31-5p was the most significant, indicating its tumor suppressive functioning. In this study, miR-31-5p was studied on larger cohort of GBM patients and also in vitro of selected GBM cell lines. Patients, Cell lines and Methods: Expression of miR-31-5p was validated on cohort of 58 GBM patients and 10 samples of non-tumor brain tissue. We have increased expression level of miR-31-5p using transient transfection of specific miRNA mimic in GBM cell lines A172, U87MG, T98MG, and U251. Cell viability and proliferation were analyzed using MTT assay and cell counting, respectively. Cell cycle analyses were performed by flow-cytometry using propidium iodide. Migration and invasion potential were measured by the wound healing assay and transwell invasion assay, respectively. Finally, potential targets of miR-31-5p were discovered using combination of bioinformatics algorithms for target prediction and GeneChip Human Gene 2.0 ST Array (Affymetrix) whole-genome expression profiling. Results: Down-regulation of miR-31-5p was successfully validated on cohort of 58 GBM patients and 10 samples of non-tumor brain tissue (p