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

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.