Reddy Krishna, Zhou Zhichao, Schadler Keri, Jia Shu-Fang, Kleinerman Eugenie S
Division of Pediatrics, The University of Texas M D Anderson Cancer Center, 1515 Holcombe Boulevard, Box 87, Houston, TX 77030, USA.
Mol Cancer Res. 2008 Jun;6(6):929-36. doi: 10.1158/1541-7786.MCR-07-2189.
Hematopoietic progenitor cells arising from bone marrow (BM) are known to contribute to the formation and expansion of tumor vasculature. However, whether different subsets of these cells have different roles in this process is unclear. To investigate the roles of BM-derived progenitor cell subpopulations in the formation of tumor vasculature in a Ewing's sarcoma model, we used a functional assay based on endothelial cell and pericyte differentiation in vivo. Fluorescence-activated cell sorting of human cord blood/BM or mouse BM from green fluorescent protein transgenic mice was used to isolate human CD34+/CD38(-), CD34+/CD45+, and CD34(-)/CD45+ cells and mouse Sca1+/Gr1+, Sca1(-)/Gr1+, VEGFR1+, and VEGFR2+ cells. Each of these progenitor subpopulations was separately injected intravenously into nude mice bearing Ewing's sarcoma tumors. Tumors were resected 1 week later and analyzed using immunohistochemistry and confocal microscopy for the presence of migrated progenitor cells expressing endothelial, pericyte, or inflammatory cell surface markers. We showed two distinct patterns of stem cell infiltration. Human CD34+/CD45+ and CD34+/CD38(-) and murine VEGFR2+ and Sca1+/Gr1+ cells migrated to Ewing's tumors, colocalized with the tumor vascular network, and differentiated into cells expressing either endothelial markers (mouse CD31 or human vascular endothelial cadherin) or the pericyte markers desmin and alpha-smooth muscle actin. By contrast, human CD34(-)/CD45+ and mouse Sca1(-)/Gr1+ cells migrated predominantly to sites outside of the tumor vasculature and differentiated into monocytes/macrophages expressing F4/80 or CD14. Our data indicate that only specific BM stem/progenitor subpopulations participate in Ewing's sarcoma tumor vasculogenesis.
已知源自骨髓（BM）的造血祖细胞有助于肿瘤脉管系统的形成和扩张。然而，这些细胞的不同亚群在此过程中是否具有不同作用尚不清楚。为了研究BM来源的祖细胞亚群在尤因肉瘤模型中肿瘤脉管系统形成中的作用，我们使用了基于体内内皮细胞和周细胞分化的功能测定法。通过对来自绿色荧光蛋白转基因小鼠的人脐带血/BM或小鼠BM进行荧光激活细胞分选，以分离出人CD34+/CD38(-)、CD34+/CD45+和CD34(-)/CD45+细胞以及小鼠Sca1+/Gr1+、Sca1(-)/Gr1+、VEGFR1+和VEGFR2+细胞。将这些祖细胞亚群分别静脉注射到携带尤因肉瘤肿瘤的裸鼠体内。1周后切除肿瘤，并使用免疫组织化学和共聚焦显微镜分析是否存在表达内皮、周细胞或炎性细胞表面标志物的迁移祖细胞。我们展示了两种不同的干细胞浸润模式。人CD34+/CD45+和CD34+/CD38(-)以及小鼠VEGFR2+和Sca1+/Gr1+细胞迁移至尤因肿瘤，与肿瘤血管网络共定位，并分化为表达内皮标志物（小鼠CD31或人血管内皮钙黏蛋白）或周细胞标志物结蛋白和α-平滑肌肌动蛋白的细胞。相比之下，人CD34(-)/CD45+和小鼠Sca1(-)/Gr1+细胞主要迁移至肿瘤脉管系统之外的部位，并分化为表达F4/80或CD14的单核细胞/巨噬细胞。我们的数据表明，只有特定的BM干/祖细胞亚群参与尤因肉瘤的肿瘤血管生成。
