肾癌旁组织高表达内皮祖细胞与肿瘤浸润相关

目的检测肾癌旁组织中CD34＋／Flk-1＋内皮祖细胞（EPCs）表达水平。探讨其与肾癌浸润性生长的相关性。方法首先建立裸鼠原位肾癌模型，建模成功后第7、12、17、21天分别处死8只裸鼠，收取癌旁组织，对照组同时间收取相应部位肾组织。采用流式细胞术检测癌旁组织中EPCs占单个核细胞的比例，RT-PCR、Westernblot方法检测血管内皮细胞生长因子（VEGF）及其配体Flk-1表达强度，免疫组织化学方法检测癌旁组织平均微血管密度（MVD）。结果肿瘤形成12、17、21d，癌旁EPCs表达均明显高于对照组（P〈0．05），整体呈现上升趋势（P〈0．01）。各时间段癌旁VEGF表达递增（P〈0．01），但均低于对照组（P〈0．01）。Flk-1表达强度呈现下降趋势（P〈0．01）。癌旁MVD表达与VEGF一致，整体低于对照组（P〈0．01）。结论EPCs在肾癌旁组织中表达水平升高，参与癌旁血管新生，可能与肾癌的浸润性生长相关。

The correlation of high expression of endothelial progenitor cells in kidney cancer adjacent tissues and tumor invasion

Objective TO test the levels of CD34＋/Flk-1＋ endothelial progenitor cells （EPCs） in kidney cancer adjacent tissues, and to explore the correlation of EPCs and tumor infiltration. Methods An orthotropic renal tumor model was successfully established. Then at days 7, 12, 17 and 21, 8 mice were put to death respectively and cancer adjacent tissues were collected. The percentage of CD34＋/Flk-1＋ cells in the kidney mononuclear cell population was detected by flow cytometry. The expression levels of VEGF, Flk-1 mRNA and protein were probed b~ real-time RT-PCR and western blot respectively. And then, microvascular density （MVD） was examined. Results The EPCs expression was increased gradually （P〈0.01）, and which was significantly higher than those in control group at days 12, 17 and 21 （P〈0.05）. The levels of VEGF were increased gradually （P〈0.01）, but significantly reduced compared with control group （P〈0.01）, and Flk-1 decreased gradually （P〈 0.01）. Compared with control group, the count of MVD in cancer adjacent tissues was significantly lessened （P〈 0.01）. Conclusion The expression of CD34＋/Flk-1＋ EPCs in kidney cancer adjacent tissues is elevated, which may participate in the formation of blood vessels and be related to tumor invasion.