Fig. 6

The dysregulated splicing function of NONO affects c-MYC expression through PRMT1. A Global splicing efficiency of TRIM25-knockdown LN229 cells and controls. Splicing efficiency was calculated as follows: splicing efficiency = transread count / 5’ and 3’ intron end first base coverage. B Quantification of alternative splicing (AS) events after TRIM25 knockdown in LN229 cells. AS events are classified into five categories: skipped exon (SE), mutually exclusive exons (MXE), alternative 5’ splice site (A5SS), alternative 3’ splice site (A3SS), and retained intron (RI). C The depths of mapped reads for different genomic regions of PRMT1 were visualized by IGV. The location of intron 2 is indicated by the dashed box. D The schematic representation of primers for the retained intron 2 in pre-mRNA of PRMT1. E qRT-PCR analysis of mature PRMT1 mRNA levels in TRIM25-knockdown LN229 cells, relative to controls. F qRT-PCR analysis of the retained intron 2 in pre-mRNA of PRMT1, GAPDH was used for normalization. G Western blotting analysis of PRMT1 protein levels in TRIM25-knockdown and control LN229 cells. H Western blotting analysis of c-MYC protein levels in TRIM25-knockdown and control LN229 cells. I Representative images of IHC for TRIM25, PRMT1, c-MYC in sections from intracranial xenografts derived from GBM#021-NC and -sh-TRIM25 implanted in nude mice, scale bar = 100 μm. ns: not significant, ∗: p < 0.05, ∗∗: p < 0.01, ∗∗∗: p < 0.001, and ∗∗∗∗: p < 0.0001