OBJECTIVES: To explore the expression profile of circular RNAs (circRNAs) and their potential roles in prognosis and progression of Wilms' tumor (WT). METHODS: Four pairs of WT and adjacent tissues were collected for high-throughput circRNA sequencing to identify the differentially expressed circular RNAs. RT-qPCR was used to verify the expression levels of the top 6 candidate circRNAs in the clinical samples. hsa_circ_0001900 was selected for analysis of its correlation with clinicopathological features and prognosis in 34 patients with WT. Sanger sequencing and RNase R digestion experiments were used to verify the cycling site and structural stability of hsa_circ_0001900 molecule. RESULTS: A total of 23 978 circular RNA molecules were identified in WT tissues by high-throughput circular RNA sequencing, and among them 614 were differentially expressed in WT. hsa_circ_0001900 showed the highest expression level among the differentially expressed circRNAs, which was consistent with the findings in clinical tumor samples and the sequencing results. Correlation analysis showed that hsa_circ_0001900 expression level was positively correlated with WT volume, and the children with high hsa_circ_0001900 expression had a lowered recurrence-free survival rate. The results of Sanger sequencing verified the circular splice site sequence of the molecule, and Rnase R digestion assay confirmed its stable covalent structure. CONCLUSIONS This study presents a comprehensive expression profile of circular RNAs in WT, and the expression level of hsa_circ_0001900 is related to the size of WT and the patients' prognosis, suggesting its possible role as a key driving gene in WT progression.
Humans ; RNA, Circular ; Wilms Tumor/pathology* ; Prognosis ; High-Throughput Nucleotide Sequencing ; Kidney Neoplasms/genetics* ; Sequence Analysis, RNA ; Male ; Female