内皮祖细胞对小鼠肾癌血管新生化的影响

Significance of endothelial progenitor cells on tumor neovascularization of renal cell carcinoma in mice

目的 检测内皮祖细胞（EPCs）在小鼠肾癌（RCC）中的分布特征，探讨EPCs在肾癌新生血管化中的作用。方法 雄性BALB／c裸鼠70只按数字表法随机分为A组（35只）、B组（35只），另取6只作为对照组（C组）。A组小鼠右肾下极移植人肾癌细胞，B组为假手术，C组不做任何处理；于实验后21、28、35、42、49d，A、B、C组各时间点分别处死7只、7只和1只小鼠，收集标本评估C组右侧正常肾组织（NT）、B组右肾损伤肾组织（ST）、A组的癌组织（1Tr）和癌旁组织（AT）中EPCs水平及分布，以及微血管密度（MVD）、血管内皮生长因子（VEGF）、基质细胞衍生因子（SDF-1）、内皮生长因子受体2（FLK）、趋化因子受体（CXCR4）等mRNA表达。结果 流式细胞仪检测显示，AT中EPCs水平在28d后逐渐升高，明显高于TT、NT及ST中的表达（P〈0．05）；TT中EPCs水平则先升高以后逐渐降低，且明显高于NT中表达（P〈0．05）。免疫荧光检测EPCs主要聚集于AT；免疫组织化学检测AT中MVD明显高于TT和NT，而TT中MVD则低于NT（P〈0．05）；AT中VEGF、FLK、SDF-1和CXCR4 mRNA水平对比，TT和NT明显升高（P〈0．05）。结论 EPCs可通过分泌促血管内皮生长因子和参与血管形成来参与肿瘤新生血管化，并以此促进肾癌的进展。

Objective To detect the distribution and frequency of mobilized endothelial progenitor ceils （EPCs） in renal call carcinoma（RCC） in mice, To explore the role of EPCs in neovascnlarization of RCC. Methods Male BALB/c nude mice were randomly divided into three groups： Rcc group（ Group A, n = 35） ; Sham group （ Group B, n = 35 ） and Normal group （ Group C, n = 6）. Mice of three groups were killed respectively at days 21, 28,35,42,49 after RCC group implant ACHN cell line, samples were harvested. The distribution and frequency of EPCs, MVD and tissue mRNA （ VEGF, SDF-1, FLK and CXCR4） in NT of Normal group, ST of Sham group, AT and TT of RCC group were evaluated. Results FCM showed that EPCs levels in AT were gradually increased after 28 days, and significantly higher than those in TT, NT and ST （P 〈 0.05 ）. EPCs levels in TT were first increased then gradually decreased but were significantly elevated compared with those in NT （ P 〈 0.05 ）. Immunofluorescence showed that EPCs were mainly distributed in the AT. Immunohistochemistry showed MVD in AT was significantly higher than that in TT and NT, but MVD in TT was lower than NT （P 〈 0.05）. The mRNA expression of VEGF, FLK, SDF-1 and CXCR4 in AT was significantly increased compared with the TT and NT （P 〈 0. 05 ）. Conclusions EPCs promotes the progress of RCC, involving the promotion on neovascularization through releasing angiogenic factors and incorporated into vascular endothelium.