CircPDSS1 accelerates malignant progression of renal cell carcinoma through sponging of miR-182-5p

Purpose: To investigate the biological function and mechanisms of circPDSS1 in triggering malignant progression of renal cell carcinoma (RCC). Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine circPDSS1 levels in 50 pairs of RCC and para-cancerous tissues. The relationship between circPDSS1 level and pathological indices in RCC patients was analyzed, while the in vitro effect of circPDSS1 in regulating RCC proliferation was assessed using cell counting kit-8 (CCK-8), colony formation and 5- ethynyl-2’- deoxyuridine (EdU) assay. The sponge effect of circPDSS1 on miR-182-5p was examined by bioinformatics analysis and dual- luciferase reporter assay, while their involvement in mediating malignant progression of RCC was analyzed using rescue experiments. In vivo, the influence of circPDSS1 on RCC growth was determined by establishing a xenograft model in nude mice. Thereafter, RCC tissues were harvested from mice to assess relative levels of miR-182-5p and Ki-67. Results: CircPDSS1 was highly expressed in RCC tissues (p < 0.05). A high level of circPDSS1 correlated with advanced tumor staging and low overall survival. Knockdown of circPDSS1 inhibited RCC cell proliferation, and CircPDSS1 sponged and negatively regulated miR-182-5p (p < 0.05). MiR182-5p was able to abolish regulatory effect of circPDSS1 on malignant proliferative potential in RCC cells. In nude mice bearing RCC, in vivo knockdown of circPDSS1 slowed down tumor growth and decreased positive expression of Ki-67 in tumor tissues (p < 0.05). Conclusion: CircPDSS1 predicts tumor stage and prognosis in RCC patients. It triggers malignant progression of RCC through sponging of miR-182-5p.