MIRNA EXPRESSION AND ITS FUNCTIONAL EFFECTS IN PAEDIATRIC ASTROCYTOMA. (3rd October 2018)

• Record Type: Journal Article
• Authors: Smith, Stuart; de los Angeles Estevez-Cebrero, Maria; Rogers, Hazel Anne; Ward, Jennifer Helen; Macarthur, Donald Cormac; Grundy, Richard
• Is Part Of: Neuro-oncology. Volume 20(2018)Supplement 5
• Page Start: v348
• Page End: v348
• Publication Date: 2018-10-03
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noy129.018
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: INTRODUCTION: Micro-Ribonucleic acids (miRNAs) are short non-protein coding RNAs involved in post-transcriptional regulation of genes by targeting the 3' region of mRNAs. They have been associated with dysregulation of oncogenes and tumour suppressors (i.e. Myc and PTEN) and signalling pathways (i.e. PDGF and EGF) in many human cancers including adult high grade glioma (HGG). However, limited work has been published about their role in paediatric astrocytoma. Here, we examine the miRNA profile of paediatric astrocytomas of different grades, their correlation to survival and micro-vascularity and their function in proliferation, invasion and migration. METHODS: The Nanostring nCounter miRNA array system analysed the expression levels of 665 miRNA sequences in 116 samples (101 astrocytoma tumours, 2 normal brain samples and 13 cell lines). Validation of selected miRNAs and their role in survival and micro-vascularity was studied by qPCR and immunohistochemistry. The functional effect of these miRNAs was evaluated by knock-down/knock-up of the sequences into the paediatric HGG cell lines SF-188 and KNS42 by transient transfection followed by Presto blue assay (assessing proliferation) and transwell assay in the presence (for invasion) or absence (for migration) of extra-cellular proteins. RESULTS: 551 miRNAs were significantly expressed between HGG, low grade glioma (LGG) and normal brain. 89 of them exhibited fold-differences higher than 3, including miR-451, miR-149 and miR-21. The latter has known oncogenic effects in adult HGG and we also observed that its overexpression in SF-188 and KNS42 resulted in significant increased proliferation of more than double after 5 days. The comparison between HGG and LGG displayed differences in the expression of 10 miRNAs, with miR-34a down-regulated in HGG and correlating to loss of its chromosomal locus in 12–13% of tumours. CONCLUSION: Specific miRNA profile signature of paediatric astrocytomas of different grades could potentially be used for prognosis and for identifying personalised therapeutic targets.