hsa_circ_0021727 facilitates esophageal squamous cell carcinoma progression by stabilizing GBX2 mRNA through interacting with EIF4A3.

Abstract

Esophageal squamous cell carcinoma (ESCC) has high mortality. The role and regulatory mechanism of hsa_circ_0021727 (circ_0021727) in ESCC remain largely unknown. This study focused on the undiscovered impact of circ_0021727 on cell cycle progression, apoptosis, and angiogenesis of ESCC. We found that circ_0021727 levels were significantly upregulated in ESCC cells. TUNEL, flow cytometry, and tubule formation assay indicated that knockdown of circ_0021727 in ESCC induced cell arrest at the G0/G1 phase, promoted apoptosis, and inhibited angiogenesis, whereas overexpression of circ_0021727 produced the opposite effect. Gastrulation brain homeobox 2 (GBX2) GBX2 was a downstream target gene of circ_0021727, and overexpression of GBX2 reversed the effect of circ_0021727 knockdown in ESCC progression. The results of the RIP and RNA pull-down showed that circ_0021727 and GBX2 mRNA bound with eukaryotic translation initiation factor 4A3 (EIF4A3). Overexpression of circ_0021727 promoted GBX2 mRNA stability by binding with EIF4A3. In a tumor xenograft model, the knockdown of circ_0021727 inhibited tumor growth, which was reversed by further overexpression of GBX2. In conclusion, circ_0021727 increased GBX2 mRNA stability by recruiting EIF4A3, which promoted cell cycle progression and angiogenesis in ESCC.