Circular RNAs (circRNAs) play critical roles in regulating the radiosensitivity of various cancers, including esophageal squamous cell carcinoma (ESCC). This research aimed to explore the role and potential mechanism of hsa_circ_0014879 in regulating ESCC radioresistance. The levels of hsa_circ_0014879, microRNA-519-3p (miR-519-3p) and cell division cycle 25A (CDC25A) were measured using quantitative real-time PCR or western blot. Cell proliferation was evaluated by colony formation assay. Cell migration and invasion were assessed by transwell and scratch assays. The levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by western blot. Xenograft assay was used to analyze the effect of hsa_circ_0014879 on radiosensitivity in vivo. The binding relationship among hsa_circ_0014879, miR-519-3p and CDC25A was confirmed by dual-luciferase reporter assay. Hsa_circ_0014879 and CDC25A were upregulated, whereas miR-519-3p was downregulated in radio-resistant ESCC tissues and cells. Depletion of hsa_circ_0014879 suppressed the proliferation, migration and invasion of radio-resistant ESCC cells. Hsa_circ_0014879 knockdown elevated radiosensitivity of radio-resistant cells by modulating miR-519-3p. Moreover, miR-519-3p enhanced the radiosensitivity of radio-resistant cells by targeting CDC25A. Also, hsa_circ_0014879 upregulated CDC25A via sponging miR-519-3p. Hsa_circ_0014879 silencing enhanced the radiosensitivity of ESCC via regulating the miR-519-3p/CDC25A pathway.

中文翻译：

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Hsa_circ_0014879通过miR-519-3p/CDC25A轴调节食管鳞状细胞癌的放射敏感性。

环状RNA（circRNA）在调节包括食管鳞状细胞癌（ESCC）在内的各种癌症的放射敏感性中发挥着关键作用。本研究旨在探讨hsa_circ_0014879在调节ESCC放射抗性中的作用和潜在机制。使用定量实时 PCR 或蛋白质印迹测量 hsa_circ_0014879、microRNA-519-3p (miR-519-3p) 和细胞分裂周期 25A (CDC25A) 的水平。通过集落形成测定评估细胞增殖。通过transwell和划痕实验评估细胞迁移和侵袭。通过蛋白质印迹法检测上皮间质转化（EMT）相关蛋白的水平。采用异种移植实验分析hsa_circ_0014879对体内放射敏感性的影响。通过双荧光素酶报告基因测定证实了 hsa_circ_0014879、miR-519-3p 和 CDC25A 之间的结合关系。在放射抗性食管鳞癌组织和细胞中，Hsa_circ_0014879 和 CDC25A 上调，而 miR-519-3p 下调。hsa_circ_0014879 的耗竭抑制了放射抗性食管鳞癌细胞的增殖、迁移和侵袭。Hsa_circ_0014879 敲除通过调节 miR-519-3p 提高抗放射细胞的放射敏感性。此外，miR-519-3p通过靶向CDC25A增强了抗放射细胞的放射敏感性。此外，hsa_circ_0014879 通过海绵 miR-519-3p 上调 CDC25A。Hsa_circ_0014879 沉默通过调节 miR-519-3p/CDC25A 途径增强 ESCC 的放射敏感性。