Abstract: ［Abstract］ Objective To investigate the mechanism of Iodine?125 seed refraining the growth of tumors cell by hindering the expression of NF?kB stomach carcinoma cells. Methods The animal models with the stomach carcinoma cells （SGC?7901） were established by subcutaneously injecting the tumor cells into nude mice. When the tumors were fully established， the animals were randomly assigned to groups. There was no significant difference in average tumor size between groups. The mice of experiment group were intravenously administered Iodine?125 seed （0.6 MBq， n=30） and mice intravenously administered 0 MBq of Iodine?125 seed were used as blank control grpup （n=30）. The controls were nothing for implantation （n=30）. The size of tumors was measured every two days and their volumes then were calculated. Anatomy analysis were done separately after 28 days of the implantation of the Iodine?125 seeds|the mRNA and proteinum expressions of NF?kB were measured by the ways of RT?PCR and immunohistochemistry. Results After Iodine?125 seeds were transplanted into the tumors of the experimental animals， tumors grew more slowly， and the tumor inhibitory rate was 38% （control group） and 43% （experimental group）. After the 28 days， the mRNA and protein express level of NF?kB in tumors were significantly decreased in experimental groups. There was significant difference between the three groups （P<0.01）. Conclusions It is one of important molecular biology mechanisms to restrain stomach carcinoma with iodine?125 seeds to decreass the expression of NF?kB in tumor cells.

Key words: stomach carcinoma, nuclear factor kappa B（NF?κB）, Iodine?125 Seeds

摘要： ［摘要］ 目的 探讨I?125粒子对胃癌细胞核因子κB（NF?κB）的表达及其抑制肿瘤细胞增殖的作用机制。方法 建立人类胃癌细胞株（SGC?7901）裸鼠皮下移植瘤模型，随机分3组，分成实验组30只、空白对照组30只和对照组30只；对照组荷瘤裸小鼠不进行干预，空白对照组小鼠植入空白粒子（0 MBq），实验组小鼠植入I?125粒子，放射剂量为14.8MBq；观察粒子植入后瘤体生长情况，粒子植入28 d时处死所有裸鼠获取肿瘤标本。对标本进行测量分析，得到裸小鼠肿瘤抑制率。用RT?PCR方法进行测定瘤组织NF?κB基因的表达水平，Western blot方法进行测定肿瘤组织内NF?κB蛋白的表达水平。结果 I?125粒子植入小鼠后，与对照组相比，实验组小鼠的肿瘤生长变慢，两组抑瘤率分别为38%和43%。实验组中肿瘤组织的NF?κB基因mRNA及蛋白表达明显降低，差异有统计学意义。结论 碘?125粒子抑制胃癌细胞增殖重要分子生物学机制之一是其抑制胃癌细胞NF?κB基因和蛋白的表达。

关键词: I?125粒子, 胃癌, 核因子κB