Exosome-Mediated Transfer of circ- GLIS3 Enhances Temozolomide Resistance in Glioma Cells Through the miR-548m/MED31 Axis.

Temozolomide (TMZ) resistance plays a critical role in the treatment of glioma. This research explored how circRNAs affect the chemosensitivity of glioma cells. The authors performed gene sequencing and selected circRNAs specifically expressed in TMZ-R cells and used them as target genes for subsequent studies. By knocking out the target gene, the authors clarify its effect on TMZ-R glioma proliferation, invasion, migration, and cell apoptosis; and through tumor-burdened animals, the authors explore the effect of the target gene in an environment. The authors revealed that circ- was significantly upregulated in TMZ-R glioma cells. Functionally, knocking down circ- could inhibit proliferation, invasion, and migration abilities of TMZ-R glioma cells. Moreover, downregulation of circ- could induce cell cycle arrest and apoptosis, while miR-548m inhibition and MED31 mRNA could reverse this progress. silencing of circ- could induce cell apoptosis and suppressed tumor growth. Mechanistically, circ- positively upregulated MED31 expression by sponging miR-548m. All these results demonstrate that circ- accelerates TMZ-R glioma progression through the miR-548m/MED31 axis.