Fig. 4

circCABIN1 promotes cancer stemness. A KEGG pathway analysis demonstrated that positive regulation of stem cell differentiation was involved and might be the downstream of circCABIN1. B GSEA analysis showed that differential genes were mainly enriched in several key stem cell related signal pathways, such as PI3K-Akt and MAPK pathway. C Heat map was performed to analyze the changed key stemness molecules after knockdown of circCABIN1. D The expression of key stemness molecules in LN229 cells were analyzed by western blot after knockdown of circCABIN1. E Fluorescence images showed the expression of circCABIN1 (Red) and ALDH1A3 (Green) in patient samples. Nuclei were counterstained with DAPI (Blue). Scale bar, 50 μm. F Pearson correlation analysis of circCABIN1 and ALDH1A3 (p = 0.0003). G Fluorescence images of patient-derived organoids was to confirm the expression of SOX2 (red) and OCT4 (green) after knockdown of circCABIN1. Nuclei were counterstained with DAPI (blue). Scale bar, 50 μm. H-I Tumorsphere formation assay and colony formation detected GSC’s self-renewal and proliferation ability after knockdown of circCABIN1. J GBM cells administrated with Sen-exo or Res-exo electroporated with circCABIN1^OE/KD were subjected to FACS to detect the proportion of CD44⁺CD133⁺ cells. K Incidences of tumorigenesis of CD45⁺CD133⁺ primary GBM cells (GBM02) infected with circCABIN1^KD in serial transplantation models. **P < 0.01 compared with untreated primary GBM cells in the first inoculation by Fisher’s exact test. L Fluorescence images showed the expression of CD133 (red) and CD44 (green) of brain frozen section from orthotopic GBM xenograft mice in indicated groups. Nuclei were counterstained with DAPI (blue). Scale bar, 10 μm. Results are presented as mean ± SD. *p < 0.05, **p < 0.01 and ***p < 0.001