Circ_0008726 promotes malignant progression of ESCC cells through miR-206/HOXA13 pathway

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors of the gastrointestinal tract. Circular RNAs (circRNAs) are involved in the pathogenesis of cancer. This study aimed to elucidate the role and molecular mechanism of circ_0008726 in ESCC.

The expression levels of circ_0008726, microRNA (miR)-206 and homeobox A13 (HOXA13) were detected by quantitative real-time PCR (QRT-PCR). Cell counting kit-8 (CCK-8) and 5-Ethynyl-2’-deoxyuridine (EdU) assays were conducted to detect the proliferative ability of ESCC cells. Apoptosis and invasion of ESCC cells were detected by flow cytometry and transwell assays. Tube formation assay was used to detect the angiogenesis of ESCC cells. The expression of related proteins was detected by western blot analysis. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to confirm the interactions among circ_0008726, miR-206 and HOXA13. Xenograft mice model was established to study the in vivo effect of circ_0008726 knockdown.

Expression of circ_0008726 was up-regulated in ESCC tissues and cells. Knockdown of circ_0008726 repressed proliferation, invasion, angiogenesis, and promoted apoptosis of ESCC cells. Circ_0008726 acted as a sponge for miR-206, and HOXA13 was a target of miR-206. The suppressive effects of circ_0008726 knockdown on cell proliferation, invasion, and angiogenesis were abated by miR-206 down-regulation. Meanwhile, overexpression of HOXA13 partially reversed the suppressive effects of miR-206 enrichment on ESCC cell malignant behaviors. Knockdown of circ_0008726 inhibited ESCC tumor growth in vivo.

In short, circ_0008726 exerted the carcinogenic effects to regulate the proliferation, invasion, angiogenesis and apoptosis of ESCC cells by targeting miR-206/HOXA13 axis.