P12.11.B The role of miRNAs in glioma in response to hypoxia

Abstract

Abstract Background Hypoxia, low oxygen, is a microenvironment that promotes tumour progression, particularly in gliomas. The regulation of many biological processes are maintained by miRNAs. The hypoxia status of glioma cells effects the regulation of processes by affecting the expression of individual miRNAs.The aims of this study is identifying significant miRNAs that are either under or overexpressed in hypoxia compared to normoxia in glioma cells and further exploring the effect of hypoxia on miR-92a-3p and miR-149-5p in gliomas on the apoptotic and cellular senescence pathways. Material and Methods A range of glioma cells were used for screening including primary cell lines: GIN28 and GIN31; low-grade cell lines: LGG19 and LGG24; paediatric cell line: SF188 and commercially available glioblastoma cell line U87. These cells were culture at both 1% (hypoxia) and 20% (normoxia) oxygen levels. Screening of miRNAs was achieved by quantitative polymerase chain reaction (qPCR) using miRNA specific primers. Knockdowns/in were achieved by transfecting with miR-92a-3p and miR-149-5p mimics and inhibitors. Caspase-glo assay was used to assess the effect of hypoxia on apoptosis. Results miRNA 92a-3p and miR-149-5p were found to be downregulated and upregulated respectively in primary gliomas cells in hypoxia compared to normoxia. These particular miRNAs are also found to have multiple targets in apoptosis and cellular senescence. Conclusion The screening of 90 miRNAs among the different categories of gliomas highlighted multiple miRNAs that were significant in hypoxia compared to normoxia. Using primary cell lines have identified hypoxia-affected miRNAs in glioblastomas. This discovery will increase our knowledge and understanding of the hypoxia effect on miRNAs which may aid and direct targeted therapy to conquer hypoxia in glioblastomas.