title: miR-331-3p regulates expression of neuropilin-2 in glioblastoma.
abstract: Aberrant expression of microRNAs (miRNAs), a class of small non-coding regulatory RNAs, has been implicated in the development and progression of high-grade gliomas. However, the precise mechanistic role of many miRNAs in this disease remains unclear. Here, we investigate the functional role of miR-331-3p in glioblastoma multiforme (GBM). We found that miR-331-3p expression in GBM cell lines is significantly lower than in normal brain, and that transient overexpression of miR-331-3p inhibits GBM cell line proliferation and clonogenic growth, suggesting a possible tumor suppressor role for miR-331-3p in this system. Bioinformatics analysis identified neuropilin-2 (NRP-2) as a putative target of miR-331-3p. Using transfection studies, we validated NRP-2 mRNA as a target of miR-331-3p in GBM cell lines, and show that NRP-2 expression is regulated by miR-331-3p. RNA interference (RNAi) to inhibit NRP-2 expression in vitro decreased the growth and clonogenic growth of GBM cell lines, providing further support for an oncogenic role for NRP-2 in high-grade gliomas. We also show that miR-331-3p inhibits GBM cell migration, an effect due in part to reduced NRP-2 expression. Finally, we identified a significant inverse correlation between miR-331-3p and NRP-2 expression in The Cancer Genome Atlas GBM cohort of 491 patients. Together, our results suggest that a loss of miR-331-3p expression contributes to GBM development and progression, at least in part via upregulating NRP-2 expression and increasing cell proliferation and clonogenic growth.
authors.affiliation: Laboratory for Cancer Medicine, Western Australian Institute for Medical Research and University of Western Australia Centre for Medical Research, Level 6, MRF Building, Rear 50 Murray Street, Perth, WA, 6000, Australia.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Epis
authors.forename: Keith M
authors.initials: KM
authors.lastname: Giles
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Candy
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Webster
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Leedman
mesh_terms: D001921:Brain / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D003114:Colony-Forming Units Assay; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics / Q000502:physiology*; D015698:Genomic Library; D005909:Glioblastoma / Q000473:pathology; D006801:Humans; D016014:Linear Models; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D039943:Neuropilin-2 / Q000235:genetics / Q000378:metabolism*; D009635:Norandrostanes / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: C514444:9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid; C544460:MIRN331 microRNA, human; D035683:MicroRNAs; D039943:Neuropilin-2; D009635:Norandrostanes; D034741:RNA, Small Interfering; C581308:neuropilin-2, human