Hsa_circ_0001707 regulates endothelial‐mesenchymal transition in esophageal squamous cell carcinoma via miR‐203a‐3p/Snail2 pathway.

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor with high mortality and poor prognosis. Despite intensive research focused on tumor suppression, the 5‐year survival rate of ESCC is lower than 15%. Therefore, investigate fundamental mechanisms involved in ESCC is on‐demand crucial for diagnostics and developing targeted therapeutic drugs. Circular RNAs (circRNAs), as an emerging class of non‐coding RNA, have been elucidated that circRNAs participated in regulating a variety of pathological processes and tumorigenesis. Nevertheless, the functional role of circRNAs in the occurrence and development of ESCC remains unclear. We identify a novel circRNA (hsa_circ_0001707), which was highly expressed in ESCC patients' tissues and cell lines. Furthermore, gain‐ and loss‐of‐function assays were performed and found that overexpression of hsa_circ_0001707 significantly promote tumor proliferation, metastasis, and invasion. By functioning as a competing endogenous RNA (ceRNA), the dual‐luciferase activity assay verified that hsa_circ_0001707 can endogenously bind with miR‐203a‐3p and regulate its downstream gene Snail2. Rescue assay further confirms that hsa_circ_0001707 downregulation could partially attenuate the facilitation effect of miR‐203a‐3p, thereby inhibiting the endothelial‐mesenchymal transition (EMT) process of ESCC. Our results suggested that hsa_circ_0001707 play an oncogenic role in the pathogenesis of ESCC, which might be a potential biomarker for diagnostics and targeting therapy. [ABSTRACT FROM AUTHOR]