Regulation of IL-8 gene expression in gliomas by microRNA miR-93.

Fabbri, Enrica; Brognara, Eleonora; Montagner, Giulia; Ghimenton, Claudio; Eccher, Albino; Cantù, Cinzia; Khalil, Susanna; Bezzerri, Valentino; Provezza, Lisa; Bianchi, Nicoletta; Finotti, Alessia; Borgatti, Monica; Moretto, Giuseppe; Chilosi, Marco; Cabrini, Giulio; Gambari, Roberto

Background: Different strategies have been proposed to target neoangiogenesis in gliomas, besides those targeting Vascular Endothelial Growth Factor (VEGF). The chemokine Interleukin-8 (IL-8) has been shown to possess both tumorigenic and proangiogenic properties. Although different pathways of induction of IL-8 gene expression have been already elucidated, few data are available on its post-transcriptional regulation in gliomas.Methods: Here we investigated the role of the microRNA miR-93 on the expression levels of IL-8 and other pro-inflammatory genes by RT-qPCR and Bio-Plex analysis. We used different disease model systems, including clinical samples from glioma patients and two glioma cell lines, U251 and T98G.Results: IL-8 and VEGF transcripts are highly expressed in low and high grade gliomas in respect to reference healthy brain; miR-93 expression is also increased and inversely correlated with transcription of IL-8 and VEGF genes. Computational analysis showed the presence of miR-93 consensus sequences in the 3'UTR region of both VEGF and IL-8 mRNAs, predicting possible interaction with miR-93 and suggesting a potential regulatory role of this microRNA. In vitro transfection with pre-miR-93 and antagomiR-93 inversely modulated VEGF and IL-8 gene expression and protein release when the glioma cell line U251 was considered. Similar data were obtained on IL-8 gene regulation in the other glioma cell line analyzed, T98G. The effect of pre-miR-93 and antagomiR-93 in U251 cells has been extended to the secretion of a panel of cytokines, chemokines and growth factors, which consolidated the concept of a role of miR-93 in IL-8 and VEGF gene expression and evidenced a potential regulatory role also for MCP-1 and PDGF (also involved in angiogenesis).Conclusion: In conclusion, our results suggest an increasing role of miR-93 in regulating the level of expression of several genes involved in the angiogenesis of gliomas.

INTERLEUKIN-8; GENE expression; GLIOMAS; MICRORNA; VASCULAR endothelial growth factors; NEOVASCULARIZATION

BMC Cancer, 2015, Vol 15, Issue 1, p1

1471-2407

Academic Journal

10.1186/s12885-015-1659-1