This study explores the role of circular RNA derived from the Multidrug Resistance Protein 4 (MRP4/ABCC4) gene, which is markedly elevated in renal cell carcinoma (RCC). Our objective is to clarify how this circular RNA contributes to the progression and development of RCC.

We quantified the presence of circular ABCC4 RNA in tissue samples, plasma and urine from patients diagnosed with RCC. In addition, the impact of this circular RNA on RCC tumour growth was assessed through studies in RCC cell lines and in animal models mimicking the disease.

Our findings reveal that circular ABCC4 RNA, specifically the variant containing exons 25–29 (circABCC4e), is upregulated in RCC cell lines and tissues. This upregulation correlates with advanced tumor stages in RCC patients, suggesting circABCC4e’s potential as a biomarker for RCC progression. Furthermore, the reduction in circABCC4e levels following tumor resection indicates its potential utility in monitoring treatment response. The mechanism by which circABCC4e promotes RCC tumor growth through the antagonism of tumor-suppressive microRNAs highlights its significance in RCC pathogenesis. These insights may inform the development of diagnostic and therapeutic strategies for RCC.

This study demonstrates that circABCC4e accelerates RCC progression by inhibiting tumor-suppressive microRNAs. Its role as a diagnostic and prognostic biomarker for RCC underscores its potential value in improving RCC management.