alphastatin抑制胃癌细胞裸鼠移植瘤血管生成的实验研究

目的探讨alphastatin对裸鼠体内新生血管形成和人胃癌细胞裸鼠移植瘤血管生成的抑制作用及机制。方法裸鼠皮下注射基质胶溶液形成基质胶体。测定alphastatin对基质胶体内新生血管的抑制作用。人胃癌BGC823细胞接种于裸鼠皮下形成移植瘤。分别于裸鼠腹腔注射磷酸盐缓冲液（PBS）和不同剂量的alphastatin（100nmol／L，0．25mg·kg^-1·d^-1；1000nmol／L，2．5mg·kg^-1·d^-1），测定各组瘤体大小、体质量并进行病理学分析，测定微血管密度（MVD）计数。分离瘤体内血管内皮细胞．经alphastatin处理后，提取细胞内蛋白，进行细胞鞘氨醇激酶（SPK）活性测定。结果裸鼠移植瘤实验中．与PBS对照组相比，两个不同剂量alphastatin实验组裸鼠移植瘤的体积和体质量均得到了不同程度的抑制[体积：（1145．96±29．89）μm^3、（612．65±23．45）μm^3比（1771±31．05）μm^3，P〈0．05；瘤体质量：（0．31±0．03）g、（0．12±0．02）g比（0．67±0．02）g，P〈0．05]。体外实验病理学证实．alphastatin减少了瘤体内MVD的数目．降低了移植瘤体内血管内皮细胞SPK活性．上述作用均呈现一定的量-效关系。结论alphastatin具有明显抑制人胃癌细胞裸鼠移植瘤血管生成的作用．这种效应与降低血管内皮细胞SPK活性、减少1-磷酸鞘氨醇（SIP）的生成有密切关系。

Alphastatin inhibits tumor angiogenesis in nude mice bearing human gastric cancer xenografts

Objective To explore the effect and mechanism of alphastatin on tumor angiogenesis in nude mice bearing human gastric cancer xenografts. Methods Nude mice were injected subcutaneously with matrigel matrix into matrigel plug. The effect of alphastatin on neovasculature inside Matrigel plug was observed. Human gastric cancer cells (BGC823) were injected subcutaneously in nude mice. After intraperitoneal injection of PBS or alphastatin,tumor volume, weight and microvascular density were analyzed. Sphingosine kinase (SPK) activity assay was used to evaluate the effect of alphastatin on tumor endothelial cells. Results In vivo, alphastatin was sufficiently potent to suppress nude mice neovascularization. Daily administration of alphastatin produced significant tumor growth suppression [tumor volume:(612.65±23.45)μm3, (1145.96±29.89)μm3 vs(1771±31.05)μm3(P<0.05), tumorweight: (0.31±0.03)g, (0.12±0.02)g vs (0.67±0.02)g (P<0.05)]. Immunohistochemical studies of tumor tissues revealed decreased microvessel density in alphastatin-treated animals as compared with controls. Alphastatin significantly inhibited tumor endothelial cells SPK activity. Conclusion Alphastatin shows potent antiangiogenic properties in nude mice,which might be closely associated with down-regulation of tumor endothelial cells SPK activity.