Exosomal circRNA_104948 Enhances the Progression of Glioma by Regulating miR-29b-3p and DNMT3B/MTSS1 Signaling

Glioma is a common type of malignancy in the central nervous system. The pathogenesis of glioma is complex and the underlying mechanisms remain largely unknown. In our study, exosomes were exacted from patient samples, and the isolated exosomes were confirmed by transmission electron microscope. The expression of circRNA_104948, miR-29b-3p and DNMT3B were determined using RT-qPCR. Proliferative activity of cell was examined using CCK-8 assay. Cell apoptotic rate was evaluated by flow cytometry. The expression levels of proliferation or apoptosis markers were determined using western blotting. Our data suggested that circRNA_104948 was upregulated in plasma exosomes/tissue samples of glioma patients and glioma cell lines. Furthermore, cell proliferation was enhanced and apoptosis was suppressed in normal astrocytes treated with exosomal circRNA_104948, and the effects were reversed by sh-circRNA_104948. In addition, miR-29b-3p is a novel target of circRNA_104948, and DNMT3B is a putative downstream molecule of miR-29b-3p. circRNA_104948 could regulate the proliferation/apoptosis of astrocytes through miR-29b-3p/DNMT3B/MTSS1 signaling, and the biological behavior changes induced by glioma-Exo were reversed by miR-29b-3p mimics; upregulated cell growth caused by miR-29b-3p inhibitors was abrogated by the knockdown of DNMT3B; the effects induced by miR-29b-3p mimics were abolished by the overexpression of DNMT3B. Our findings revealed the important roles of circRNA_104948 on the development of glioma, and circRNA_104948/miR-29b-3p/MTSS1/DNMT3B pathway may be a potential candidate for the target therapy of glioma patients.