CircSETD3 (Hsa_circ_0000567) Suppresses Hepatoblastoma Pathogenesis via Targeting the miR-423-3p/Bcl-2-Interacting Mediator of Cell Death Axis.

Background

Up until now, the role of circSETD3 (Has_circ_0000567) in regulating cancer development has been reported in several tumors, but the role and regulatory mechanism of circSETD3 in hepatoblastoma (HB) remain unclear.

Methods

The qPCR and western blotting were used to determine the mRNA and protein levels in the present study. Stability of circular RNA was detected by RNA digested experiments. The gain-of-function and rescue experiments were used to explore the function and mechanism of circSETD3 in HB. Cell counting kit-8, colony formation, transwell assay, and xenograft mice model were used to detect effects and regulatory mechanism of circSETD3/miR-423-3p/Bim axis on cell aggressive phenotype in vitro and in vivo.

Results

Here, we identified that circSETD3 downregulated in both HB clinical tissues and cell lines, compared to that of normal tissues and cells. Further gain-of-function experiments validated that circSETD3 overexpression inhibited cell proliferation, viability, migration, epithelial-mesenchymal transition (EMT) and tumorigenesis, and induced cell apoptosis in HB cells. Next, we validated that miR-423-3p targeted both circSETD3 and 3' untranslated region (3'UTR) of Bim, and circSETD3 positively regulated Bim in HB cells through sponging miR-423-3p in a competing endogenous RNA (ceRNA)-dependent manner. Furthermore, through conducting reversal experiments, we evidenced that the inhibiting effects of circSETD3 overexpression on HB development were abrogated by upregulating miR-423-3p and downregulating Bim.

Conclusion

Taken together, we evidenced that circSETD3 sponged miR-423-3p to upregulate Bim, resulting in the inhibition of HB development.