Fig. 5: CircSPIRE1 suppresses EMT of RCC cells through stabilizing GALNT3 mRNA.

A Kaplan−Meier analysis of DFS in RCC patients with low versus high expression of GALNT3. The P-value was determined by the Log-rank test. B Positive correlation between GALNT3 expression and circSPIRE1 expression in 142 clinical samples of RCC. C qRT-PCR analysis of GALNT3 expression in 14 RCC patients with metastasis and 14 patients without metastasis. Data represent mean ± S.D.; the P values were determined by Student’s t test. D Transwell assays showing that circSPIRE1 suppresses the migration ability of RCC cells depending on GALNT3. Top, representative images of the Transwell assay. Scale bar, 100 µm. Bottom, numbers of migrating cells (n = 5/group). E Western blots of epithelial and mesenchymal markers upon overexpression of circSPIRE1 in PDX LM and knockdown of circSPIRE1 in original PDX. F Western blots of enhanced epithelial markers upon overexpression of circSPIRE1 was reversed by GALNT3 knockdown in PDX LM and reduced epithelial markers upon knockdown of circSPIRE1 was reversed by GALNT3 overexpression in original PDX. G E-cadherin O-GalNAc glycosylation decreases in PDX LM comparing with original PDX and increases upon circSPIRE1 overexpression. Knockdown of GALNT3 reversed the effect of circSPIRE1 overexpression. H E-cadherin retention in the Golgi increases in PDX LM compared to original PDX and decreases upon circSPIRE1 overexpression. Knockdown of GALNT3 reversed the effect of circSPIRE1 overexpression. Scale bar, 10 µm. Pearson’s coeff was used as quantifications.