Cell type-specific Effect of miRZip-21 to Suppress miR-21 in Human Glioma Cell Lines

Abstract

Background: There are different subtypes of brain tumors, classified according to the origin of the abnormally proliferated glial cells. Glioblastoma multiforma (GBM) is the grade 4 of brain tumors, gliomas, with the least life expectancy. microRNAs (miRNAs) are small, single stranded, non-coding RNAs with 20-25 nt length with post-transcriptional gene regulatory activity. An altered expression of miRNAs is linked to developmental disorders and some diseases, most importantly cancers. miR-21 is a well-known microRNA, overexpressed in almost all cancer types, including brain tumors. It targets several genes with vital roles in cellular pathways involve in proliferation, invasion and metastatic behavior. Exosomes are 30-100 nm extracellular vesicles which are packed with various molecules, including miRNAs. rnMethods and Results: Here, we suppressed miR-21 expression level in HEK-293T cell line by transfecting the cells with the miRZip-21 vector. However, when the secreted exosomes transferred to a glioblastoma cell line, U87-MG, we did not observe any suppression effect on host cells’ miR-21 expression level. Moreover, analyzing miRZip-21-enriched cell media effects on three other brain cell lines 1321N1, A-172 and DAOY revealed that exocrine miRZip-21 have a cell type-specific effect. rnConclusion: These data suggest that cell lines from different brain tumor subtypes could exert different response to microRNA-based therapies, based on their cellular origin and clinical behaviors.