Circular RNA EGLN3 silencing represses renal cell carcinoma progression through the miR-1224-3p/HMGXB3 axis

Abstract

Background: Renal cell carcinoma (RCC) is a common tumor of the urinary system, and its global incidence is increasing annually. Circular RNAs (circRNAs) are involved in RCC tumorigenesis; however, the role of circ-EGLN3 (hsa_circ_0031594) derived from the Egl nine homolog 3 (EGLN3) gene in RCC remains undetermined.

Methods: Circ-EGNL3 expression was examined before and after RNase R and actinomycin treatments in RCC cells and tissues. Cell proliferation, migration, and invasion were assessed using the CCK-8 assay, EdU staining, and wound-healing and Transwell assays. The interactions between microRNA (miR)-1224-3p and circ-EGLN3, and between miR-1224-3p and HMG box domain containing 3 (HMGXB3) were predicted by bioinformatics analysis and validated by dual-luciferase reporter assay.

Results: Circ-EGLN3 was identified using RNase R and actinomycin treatments. Circ-EGLN3 was upregulated in RCC cells and tissues and correlated with poor overall survival. Silencing of circ-EGNL3 decreased RCC cell proliferation, migration, and invasion. Mechanistic studies indicated that circ-EGNL3 acts as a sponge for miR-1224-3p, which targeted HMGXB3. Circ-EGNL3 indirectly upregulated HMGXB3 by targeting miR-1224-3p, and overexpression of circ-EGLN3 reversed the repressive effects of miR-1224-3p on RCC.

Conclusion: Circ-EGLN3 regulated RCC progression through the miR-1224-3p/HMGXB3 axis, suggesting its potential as a therapeutic target.

Keywords: Circular RNA EGNL3; HMG box domain containing 3; Renal cell carcinoma; miR-1224-3p.