中文摘要：

目的：证明胃癌血管靶向肽GX2能够与胃癌血管内皮细胞特异性结合,在体内对胃癌血管具有靶向性。方法：体外实验,合成GX2与FITC的复合物FITC-GX2,分离原代人脐静脉内皮细胞HUVEC,将HUVEC与人胃癌细胞系SGC7901共培养,建立共培养血管内皮细胞模型来模拟胃癌血管,利用免疫荧光的方法观察GX2与共培养内皮细胞Co-HUVEC的结合情况;体内实验,构建99mTc标记的GX2分子示踪探针,SPECT显像观察GX2的胃癌血管靶向性。结果：免疫荧光结果显示GX2能与Co-HUVEC特异性结合,而与人胃癌细胞SGC7901不结合;SPECT显像结果证明了GX2在荷瘤裸鼠体内能够浓集到肿瘤部位,具有良好的靶向性。结论：GX2能与胃癌血管内皮细胞特异性结合,且具有在体靶向到胃癌血管的能力;GX2具有胃癌诊断的潜在价值,并能应用于胃癌血管抑制治疗。

英文摘要：

Objective： To identify targeting ability of GX2 homing to gastric cancer vasculature in vivo and in vitro.Methods： Hu-man umbilical vein endothelial cells（HUVEC） were isolated and cultured,and the tumor endothelial cell coculture model（Co-HUVEC） was prepared using HUVEC and the human gastric cancer cell line SGC7901 in Transwell plates.A FITC-GX2 complex were synthe-sized and used in immunofluorescence staining in vitro.Samples were examined using a fluorescence microscope and binding specificity to Co-HUVEC was evaluated.Besides,GX2 was labeled with the radioactive isotope 99mTc,and targeting efficacy was observed using SPECT imaging in the nude mice model bearing SGC7901 tumor xenografts.Results： Immunofluorescence staining demonstrated that GX2 bound specifically to Co-HUVEC but not to SGC7901 cells.SPECT imaging showed that GX2 targeted the tumor tissue.Conclusions： GX2 can bind specifically to Co-HUVEC and home to gastric cancer vasculature.GX2 can also be applied to diagnosis and therapy for tumor angiogenesis.