METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of circ_0001686, microRNA-876-5p (miR-876-5p) and spindlin 1 (SPIN1). Counting Kit-8 (CCK-8) assay, EdU assay, flow cytometry and transwell assay were applied to evaluate cell viability, cell proliferation, cell apoptosis and cell invasion capacities. Radiosensitivity was monitored by colony formation assay. The target relationship between miR-876-5p and circ_0001686 or SPIN1 was identified by dual-luciferase reporter assay. The protein level of SPIN1 was measured by western blot assay. Xenograft tumor models were used to analyze the influence of circ_0001686 on radiosensitivity and tumor growth in vivo.
RESULTS: The expression levels of circ_0001686 and SPIN1 were increased, while miR-876-5p was decreased in esophagus cancer tissues and cells. Interference of circ_0001686 constrained cell proliferation and invasion, but promoted cell apoptosis and radiosensitivity. Additionally, miR-876-5p was the target of circ_0001686 and miR-876-5p inhibition effectively ameliorated the impacts of circ_0001686 deficiency on tumorigenesis and radiosensitivity. Moreover, SPIN1 was a direct target of miR-876-5p and SPIN1 overexpression partially overturned the effects of miR-876-5p transfection on tumor progression and radiosensitivity. Importantly, circ_0001686 could sponge miR-876-5p to regulate SPIN1 expression. In addition, circ_0001686 silencing also constrained tumor growth and increased radiosensitivity in vivo.
CONCLUSIONS: Circ_0001686 contributed to the progression and radioresistance of esophagus cancer cells via regulating SPIN1 expression by targeting miR-876-5p, providing a new therapeutic target for improving the prognosis of esophagus cancer patients.
方法:采用实时定量聚合酶链反应(qRT-PCR)检测circ_0001686、microRNA-876-5p(miR-876-5p)和spindlin1(SPIN1)的表达水平。计数试剂盒-8(CCK-8)测定,EdU分析,流式细胞术和transwell分析用于评估细胞活力,细胞增殖,细胞凋亡和细胞侵袭能力。通过集落形成测定监测放射敏感性。miR-876-5p与circ_0001686或SPIN1之间的靶关系通过双荧光素酶报告基因测定来鉴定。通过蛋白质印迹测定法测量SPIN1的蛋白质水平。使用异种移植肿瘤模型来分析circ_0001686对体内放射敏感性和肿瘤生长的影响。
结果:circ_0001686和SPIN1的表达水平升高,而miR-876-5p在食管癌组织和细胞中降低。干扰circ_0001686限制细胞增殖和侵袭,但促进细胞凋亡和放射敏感性。此外,miR-876-5p是circ_0001686的靶标,抑制miR-876-5p有效改善了circ_0001686缺乏对肿瘤发生和放射敏感性的影响。此外,SPIN1是miR-876-5p的直接靶标,SPIN1过表达部分推翻了miR-876-5p转染对肿瘤进展和放射敏感性的影响。重要的是,circ_0001686可以海绵化miR-876-5p调节SPIN1的表达。此外,circ_0001686沉默也限制了体内肿瘤生长和增加的放射敏感性。
结论:Circ_0001686通过靶向miR-876-5p调节SPIN1表达促进食管癌细胞的进展和放射抗性,为改善食管癌患者的预后提供了新的治疗靶点。