目的：探讨COUP-TFⅡ在胃癌中对淋巴转移相关因子VEGFR3-NRP2轴的调控分子机制。方法：收集2015 年3月至2015 年8月在滨州医学院附属医院手术切除的60 例胃癌组织和相应的癌旁组织及正常胃黏膜活检组织，用免疫组化和qPCR法检测COUP-TFⅡ、VEGFR3和NRP2的表达；培养胃癌细胞SGC7901 和BGC823，构建过表达和siRNA-COUP-TFⅡ质粒后转染SGC7901 细胞，用WB和qPCR 检测转染后SGC7901 细胞中COUP-TFⅡ、VEGFR3、NRP2 的表达，用免疫共沉淀（CHIP）和双荧光素酶报告基因实验验证COUP-TFⅡ与VEGFR3-NRP2 轴的靶向关系。结果:免疫组化检测显示，VEGFR3、NRP2、COUP-TFⅡ在胃癌组织中呈高表达（P<0.01）；qPCR 结果显示，与癌旁组织和正常组织相比，胃癌组织VEGFR3、NRP2和COUP-TFⅡ的mRNA 呈高表达（P<0.05 或P<0.01）；WB 和qPCR 法结果显示，与对照组相比，过表达COUP-TFⅡ组SGC7901 细胞中COUP-TFⅡ mRNA和蛋白水平表达均显著升高（均P<0.01）；敲减组SGC7901 细胞中COUP-TFⅡ mRNA和蛋白水平均显著下降（P<0.05 或P<0.01），且VEGFR3 和NRP2 mRNA 水平也均显著下降（均P<0.01）；CHIP 结果显示，SGC7901 和BGC823 细胞中COUP-TFⅡ抗体的免疫共沉淀物中含有VEGFR3和NRP2启动子DNA序列；双荧光素酶报告基因实验结果显示，COUP TFⅡ表达水平与VEGFR3和NRP2表达水平呈正相关。结论：COUP-TFⅡ在胃癌组织中高表达且对VEGFR3-NRP2轴存在正性调控作用，且在胃癌中高表达，COUP-TFⅡ可能为胃癌治疗的新靶点。

Objective: To explore the molecular mechanism of COUP-TFⅡ regulating lymphatic metastasis-related factor VEGFR3-NRP2 axis in gastric cancer. Methods: Sixty cases of gastric cancer tissues and paracancerous tissues surgically resected at the Binzhou Medical University Hospital between March 2015 and August 2015 were collected, and the expression of COUP-TFⅡ, VEGFR3 and NRP2 in the tissues was detected by immunohistochemistry and qPCR. Gastric cancer SGC7901 and BGC823 cells were cultured, and COUP-TF Ⅱ overexpression and siRNA-COUP-TF Ⅱ plasmids were constructed and further transfected into SGC7901 cells. The expression of COUP-TFⅡ, VEGFR3 and NRP2 in SGC7901 cells after transfection was detected by WB and qPCR, and the targeting relationship between COUP-TFⅡ and VEGFR3-NRP2 axis was verified by immunoprecipitation (CHIP) and dual-luciferase reporter assay. Results: Immunohistochemistry showed that VEGFR3, NRP2, and COUP-TFⅡ were highly expressed in gastric cancer tissues (all P<0.01). qPCR results showed that the mRNA levels of VEGFR3, NRP2 and COUP-TFⅡ were also highly expressed in gastric cancer tissues compared with paraneoplastic and normal tissues (P<0.05 or P<0.001). WB and qPCR methods showed that compared with the control group, both the mRNA and protein levels of COUP-TFⅡ were significantly higher in the COUP-TFⅡ overexpression group (both P<0.01); while the mRNA and protein levels of COUP-TFⅡ were significantly decreased in the SGC7901 cells of COUP-TFⅡ knockdown group (P<0.05 or P<0.01), and the VEGFR3 and NRP2 mRNA levels were also significantly decreased (both P<0.01). CHIP results showed that the immunoprecipitates of COUP-TFⅡ antibodies in SGC7901 and BGC823 cell lines contained VEGFR3 and NRP2 promoter DNA sequences. The results of dual-luciferase reporter assay showed that COUP-TFⅡ expression level was positively correlated with VEGFR3 and NRP2 levels. Conclusion: COUP-TF Ⅱ has a direct positive regulatory effect on the VEGFR3-NRP2 axis and is highly expressed in gastric cancer. COUP-TFⅡ may serve as a new target for the treatment of gastric cancer.

山东省自然科学基金项目（No. ZR2020MH060）；2021年大学生创新创业训练计划立项项目（No. 202110440120）