中文摘要：

目的：研究尼妥珠单抗（h-R3）对人食管鳞癌KYSE450细胞的放射增敏效应。方法：利用四氮唑盐（MTT）比色法分析hR3、X线照射及两者联合对人食管癌KYSE450细胞的生长抑制作用,通过流式细胞仪分析细胞周期分布及细胞凋亡的变化。采用克隆形成实验检测h-R3对食管癌细胞系放射敏感性的影响,多靶单击模型拟合细胞存活曲线。同时采用基因芯片技术对hR3组、h-R3联合照射组两组进行检测,筛选不同组之间的差异基因,用生物信息学分析差异基因功能。结果：h-R3组、照射组和h-R3联合照射组对KYSE450细胞生长均有抑制作用,且联合照射组对KYSE450细胞的生长抑制作用最强（35.25±5.62）%,明显高于h-R3组（16.12±8.73）%和照射组（27.64±6.66）%（F=10.953,P〈0.001）。联合照射组细胞出现明显的G2期阻滞和细胞凋亡,G2期细胞和凋亡细胞所占比例最高,分别达到（29.37±7.29）%（F=17.299,P〈0.001）和（18.80±2.03）%（F=85.691,P〈0.001）。多靶单击模型显示,h-R3联合照射组的SF2、Do、Dq值均较单纯照射组减小（SER=1.63）,提示h-R3对KYSE450细胞有放射增敏作用。基因芯片分析发现h-R3可通过下调EGF/PDGF信号传导通路的相关基因发挥放疗增敏作用。结论：尼妥珠单抗能有效抑制人食管癌KYSE450细胞的生长,与X射线照射联合后能够促进细胞凋亡,增强G2期阻滞效应,能够增强食管癌KYSE450细胞对X射线的放疗敏感性,此效应与下调表皮生长因子受体（epidermal growth factor receptor,EGFR）信号传导通路的相关基因有关。

英文摘要：

Objective： To study the radiation-sensitizing effects of nimotuzumab and X-ray radiotherapy on human esophageal carcinoma KYSE450 cells. Methods： Human esophageal carcinoma cells KYSE450 were treated with nimotuzumab, irradiation, and the combination of both. Cell growth inhibition was evaluated by MTT assay, and cell cycle distribution and apoptosis were analyzed by flow cytometry assay. Cell radiosensitivity was tested by clonogenic assay, and the survival curve was fitted using multi-target single-hit model. The combination and accelerated radiation groups were tested by microarray technology, and the differentially expressed genes were screened among the two groups. Results： The growth of KYSE450 cells was inhibited in three groups, namely, the group treated with nimotuzumab, the group treated with irradiation, and the group treated with both. The group treated with both nimotuzumab and irradiation resulted in the highest inhibition rate（35.25%±5.62%） compared with that of the nimotuzumab（16.12%±8.73%） and irradiation groups（27.64% ± 6.66%）（F=10.953, P〈0.001）. The highest rates of G2 phase arrest and cell apoptosis were observed in the group treated with the combination of nimotuzumab（29.37%±7.29%）（F=17.299, P〈0.001） and irradiation（18.80%±2.03%）（F=85.691,P〈0.001）. Multi- target single- hit model showed that the values of SF2, Do, and Dq in the group with both treatments were smaller than those of the irradiation group with sensitization enhancement ratio of 1.63, which confirmed the radiosensitization effect of nimotuzumab on KYSE450 cells. Microarray technology analysis found that nimotuzumab can enhance the radiosensitivity of esophageal squamous cell carcinoma by cutting the genes of EGF/PDGF signaling pathways. Conclusion： This experiment shows that nimotuzumab can effectively inhibit the growth of human esophageal cancer cell KYSE450. Nimotuzumab can also promote apoptosis and G2 phase arrest when combined with X-ray radiotherapy, thereby enhancing the