中文摘要：

目的 研究CD133＋细胞在肿瘤组织中的分布特征,探讨其与微生态环境的关系.方法 用CD133＋肿瘤球或转红色荧光蛋白（RFP）基因的胶质瘤干细胞SU-3行裸小鼠原位、右腋皮下和腹腔等异位接种,致瘤后取荷瘤鼠全脑及整个皮下移植瘤组织行HE染色以及CD133免疫组织化学和免疫荧光染色,分别在光镜、荧光显微镜和激光共聚焦显微镜下观察移植瘤的组织结构和CD133＋肿瘤细胞的分布特征.结果 在光镜下,原位接种的CD133＋肿瘤细胞的分布有一定规律性,从形态上可分为成簇、成对和单个分布;从部位上可分为肿瘤血管旁、血管内皮、正常组织中和脑室内.皮下接种的CD133＋肿瘤细胞成簇或散在分布于肌肉和脂肪组织中,还可见CD133免疫复合物分布于血管壁及其基质.在荧光显微镜和激光扫描共聚焦显微镜下可见,有些肿瘤血管内皮、血管旁的细胞共表达CD133和RFP.结论 在荷瘤鼠体内成簇生长的CD133＋细胞实际上是类似体外生长的肿瘤干细胞（CSCs）球,而成对和单个生存的CD133＋细胞分别代表CSCs与微生态环境相关的对称和不对称分裂;沿血管分布的CD133＋细胞是依赖微生态环境生存的细胞,而远离血管或远离肿瘤组织、孤立于正常组织中的CD133＋细胞是播散的CSCs或神经干细胞,属不受微生态环境控制的细胞.

英文摘要：

Objective CD133 ＋ tumor cells are regarded as cancer stem cells （ CSCs）, responsible for tumor initiation, development, and relevant with chemo- and radio-resistance of tumors. However, how the destiny of CD133＋ cells is regulated by their niche remains largely unknown. In this study the interpretation of the relationship between CD133 ＋ cells and their niche were performed through investigating the distribution characteristics of CD133＋ cells in transplanted human glioma xenograft. Methods CD133 ＋tumor cell spheres or tumor cells transfected with red fluorescent protein （RFP） gene were implanted in situ,subcutaneously or intraperitonealy in nude mice, then the xenografts were dissected and embedded in paraffin, stained with hematoxylin-eosin （HE）, tumor tissues were further stained against CD133 with immunohistochemical and immunofluorescent techniques. The pathological structures of tumors and distribution characteristics of CD133 ＋ tumor cells were observed under microscope and confocal fluorescence microscope. Results Under microscope, distribution of CD133 ＋ glioma cells showed certain regularity and can be classified morphologically into three types： cell clusters, in pairs and single cells. Distribution of CD133＋ cells can also be classified according to their distribution location： accumulating around tumor vasculature areas, among the vascular endothelial cells, or in the normal brain tissue and ventricles. Under fluorescence microscope and laser confocal microscope, some of vascular endothelial cells inside the tumor region and some cells around tumor vessels co-express CD133 and RFP. Conclusion CD133 ＋ tumor cell clusters in nude mice are actually similar to those in CSCs spheres cultured in vitro. The single CD133 ＋cells and CD133＋ cells in pairs represent asymmetric and symmetric division of CSCs within the CSCs niche,respectively. CD133 ＋ cells residing along tumor vessels are CSCs depending on CSC niche, and those locating far away from tumor blood vessels or