Fig. 5

cNDC80 functions as a sponge for miR-139-5p. A Evaluation of cNDC80 binding to the AGO2 protein was performed using RNA immunoprecipitation (RIP) and RT-qPCR techniques. B Testing on agarose gel electrophoresis confirmed that cNDC80 binds to the AGO2 proteins. The cDNA for cNDC80 is 167 base pairs long. C cNDC80-overexpressing U87 cells were used in combination with a cNDC80-specific probe and an NC probe for circRNA in vivo precipitation (circRIP) experiments. Potential miRNAs connected to cNDC80 were examined using RT-qPCR assays. The enrichment of cNDC80 and putative miRNAs was normalized by comparing it to the control probe. D Possible binding site sequences between cNDC80 and miR-139-5p, both in the wild-type (WT) and mutated-type (MUT). E Dual-luciferase reporter assays were carried out to identify the relationship between cNDC80 and miR-139-5p. F The connection between cNDC80 and miR-139-5p expression levels was analyzed using Pearson’s correlation (r = − 0.4173, P = 0.0019). G FISH was applied to examine the colocalization of cNDC80 and miR-139-5p in transfected GBM cells. Scar bar 100 um. H qRT–PCR was applied to examine at the expression of miR-139-5p in thirty high-grade gliomas, fifteen low-grade gliomas, and eight normal brain tissues. I In treated GBM cells, qRT–PCR was used to verify the expression of miR-139-5p. Each experiment was conducted three times, and the findings are shown as mean ± SD. (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001)