Abstract 5256: MiRNA-31-5p expression in glioblastoma tissue and effects of its replacement in glioblastoma cells
Authors: Sana Jiri , Besse Andrej , Ondracek Jakub , Vecera Marek , Fadrus Pavel , Kren Leos , Mlcochova Hana , Illiev Robert , Mlcochova Jitka , Vychytilova Petra , Hezova Renata , Juracek Jaroslav , Slaby Ondrej 
Published: August 2015

Abstract
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&lt;0.001). MiR-31-5p was significantly associated also with progression-free and overall survival of GBM patients. Transient expression of miR-31-5p led to the significant decrease of GBM cell proliferation and viability in A172, U87MG, T98G, and U251 cell lines (t-test; p &lt; 0.05) due to the cell cycle arrest in G1 phase. Moreover, transfected A172 and U251 cells had a lower migration and invasiveness potential in comparison with control cells (t-test; p &lt; 0.05). Finally, analysis of global gene expression profiles together with predicted mRNA targets revealed several interesting targets of miR-31-5p, which are involved in crucial signaling pathways of GBM.
Conclusion:
Taken together, our data suggest that miR-31-5p is not only powerful diagnostic marker as showed previously but seems to be promising therapeutic target in GBM patients. This work was supported by grants of Internal Grant Agency of the Czech Ministry of Health no. NT13514-4/2012, NT/13860-4/2012, NT/13549-4/2012, NT/13547-4/2012; and project “CEITEC - Central European Institute of Technology” (CZ.1.05/1.1.00/02.0068).
Citation Format: Jiri Sana, Andrej Besse, Jakub Ondracek, Marek Vecera, Pavel Fadrus, Leos Kren, Hana Mlcochova, Robert Illiev, Jitka Mlcochova, Petra Vychytilova, Renata Hezova, Jaroslav Juracek, Ondrej Slaby. MiRNA-31-5p expression in glioblastoma tissue and effects of its replacement in glioblastoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5256. doi:10.1158/1538-7445.AM2015-5256