Fig. 5: CircPLOD2a/b promote GBM cell invasion and migration by suppressing XIRP1 through binding to HuR.

A Heatmap and (B) Volcano plot of DEGs in KD-circPLOD2a U87 cells compared to negative control cells under hypoxia. In total n = 57 up-regulated and n = 114 up-regulated genes were displayed. C, D Expression of 4 up-regulated genes in RNA-seq data in (C) KD-circPLOD2a and (D) OE-circPLOD2a U87 cells examined by qRT-PCR. E Expression of these 4 genes in KD-HuR cells. F, G Expression of XIRP1 in (F) KD-circPLOD2b and (G) OE-circPLOD2b cells. H, I Binding of (H) circPLOD2a and (I) XIRP1 to HuR were detected by RIP assay in U87 OE-circPLOD2a and control cells. J, K Binding of (J) circPLOD2b and (K) XIRP1 to HuR were detected by RIP assay in U87 OE-circPLOD2b and control cells. L, M The expression (L) mRNA and (M) protein level of XIRP1 were rescued by overexpression of HuR in OE-circPLOD2a and OE-circPLOD2b cells. Relative integrated density normalized to β-actin was marked above each band. N OE-HuR U87 and LN229 cells were treated with actinomycin D (5 μg/ml). The relative expression of XIRP1 was detected by qRT-PCR at different time points post actinomycin D treatment. O, P Transwell invasion assays illustrate that knockdown of XIRP1 in (O) KD-circPLOD2a or (P) KD-circPLOD2b U87 cells could rescue the inhibition of cell invasion and migration induced by knockdown of these two circRNAs under hypoxia. scale bar: 100 μm. (Q and R) Wound healing assays illustrate that knockdown of XIRP1 in (Q) KD-circPLOD2a or (R) KD-circPLOD2b U87 cells could rescue the inhibition of cell migration ability under hypoxia. Scale bar: 250 μm. n = 3 replicates unless otherwise noted. Data are shown as mean ± SEM (error bars) and analyzed using ANOVA. Scr: Scramble.