Background and Objective: Exosomes communicate inter-cellularly and miRNAs play
critical roles in this scenario. MiR-214-5p was implicated in multiple tumors with diverse functions
uncovered. However, whether miR-214-5p is mechanistically involved in glioblastoma, especially via
exosomal pathway, is still elusive. Here we sought to comprehensively address the critical role of
exosomal miR-214-5p in glioblastoma (GBM) microenvironment.
Methods: The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and
migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines
were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was
interrogated by luciferase reporter assay. Protein level was analyzed by Western blot.
Results: We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with
poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and
migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia
upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214-
5p in this setting.
Conclusion: Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia
via exosomal transfer.