纳米氧化铁双歧杆菌LTA对实验性胃癌抑制效果的影响

目的探讨纳米氧化铁（Fe3O4）双歧杆菌脂磷壁酸（Lipoteichoic acid,LTA）对实验性胃癌体内抑制效果的影响及其抑瘤途径。方法用人胃癌BGC823细胞建立裸鼠移植瘤模型,用硝酸还原酶法检测各剂量组裸鼠腹腔巨噬细胞分泌NO和iNOS的含量,用免疫组化法检测移植瘤内VEGF、Survivin和TAMs的表达。结果纳米Fe3O4-LTA各组与阴性对照组相比,NO生成量增加、iNOS活性增高,差异有非常显著性（P〈0.01）。移植瘤内VEGF、Survivin和TAMs蛋白表达显著低于阴性对照组（P〈0.01）。结论纳米Fe3O4-LTA对人胃癌裸鼠移植瘤的生长具有明显的抑制作用,其抑瘤机制可能与激活巨噬细胞,使其分泌多种具有杀瘤作用的活性因子以及下调胃癌内VEGF、Survivin和TAMs的表达,进而抑制其血管形成有关。

Inhibition of a heterologous graft model for human gastric cancer in nude mice by Nano-sized-Fe3O4-Lipoteichoic acid from Bifidobacterium in vivo

Objective To explore the inhibition effect of Nano-sized-Fe3 O4-Lipoteichoic acid from Bifutobacterium on experimental gastric cancer in vivo and the pathway of antitumor. Methods Sixty nude mices subcutaneously transplan- ted with BGC-823 human gastric cancer ceils were administered with different doses of Nano-sized-Fe3O4-LTA by intraperitoneal injection. The production of NO and iNOS of nude mice peritoneal macrophages were assessed by Griess reaction. The expression level of vascular endothelial growth factor（VEGF） , Survivin and tumor associated macrophages （TAMs） of gastric cancer were detected by using immunohistochemical method. Results The content of NO and activity of iNOS of nude mice peritoneal macrophages in Nano-sized-Fe3 O4-LTA injection group were significantly higher than those in NS group. The positive cell density of VEGF, Survivin and TAMs in Nano-sized-Fe3 04-LTA injection group were significantly lower than those in NS ＂group. Conclusions The Nano-sized-Fe3O4-LTA from Bifidobacterium exerts an inhibiting effect on the growth of human gastric cancer in nude mice. The possible antitumor mechanisms are to stimulate peritoneal macrophages to produce some antitumor factors and decrease the expression of VEGF, Survivin and TAMs and inhibit the angiogenesis of human gastric cancer.