Fig. 5

circPSD3 regulates the uPA system. (A) Volcano plot of differentially expressed genes between the circPSD3-overexpression and control groups. (B and C) qRT-PCR validation of the top five up and downregulated genes in HCC-LM9 and SK-Hep-1 cells. (D and E) circPSD3 knockdown of HCC-LM9 and SK-Hep-1 cells demonstrating the regulatory relationship between circPSD3 and SERPINB2. (F) Western blotting analysis of uPA system protein expression in artificially constructed circPSD3 groups. (G–I) Relative mRNA levels of SERPINB2, uPAR, and uPA in 48 paired HCC and non-cancerous tissues. (J) Pearson correlation analysis showing a positive correlation between circPSD3 and SERPINB2 in 48 HCC tissues. (K) Immunohistochemical staining revealing the protein levels of SERPINB2 and uPAR in two patients with HCC and PVTT. Scale bar, upper = 100 μm; lower = 20 μm. (L) Wound healing assays in the indicated cells. Scale bar = 100 μm. (M) Transwell assays showing the migration and invasion of the indicated cells. Scale bar = 100 μm. Data are shown as the mean ± SD. Statistical analyses were performed using unpaired Student’s t-tests (NS, no statistical significance; **p < 0.01; ***p < 0.001; ****p < 0.0001). circPSD3, circRNA pleckstrin and Sect. 7 domain containing 3; HCC, hepatocellular carcinoma; PVTT, portal vein tumor thrombosis; qRT-PCR, quantitative real-time PCR; SERPINB2, serpin family B member 2; uPA, urokinase-type plasminogen activator; uPAR, uPA receptor