Erschienen in:
01.05.2011 | Original Paper
Bone marrow cells participate in tumor vessel formation that supports the growth of Ewing’s sarcoma in the lung
verfasst von:
Zhichao Zhou, Keri Schadler Stewart, Ling Yu, Eugenie S. Kleinerman
Erschienen in:
Angiogenesis
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Ausgabe 2/2011
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Abstract
An MHC-mismatch bone marrow (BM) transplant Ewing’s sarcoma mouse model was used to investigate whether BM cells participate in the vessel formation that support Ewing’s sarcoma lung metastasis. BM cells from H-2Kb/d donor mice were transplanted into sublethally irradiated H-2Kd recipient mice. Donor BM cells were identified using the H-2Kb marker. Engraftment was confirmed by identifying the H-2Kb IL-1β-type specific polymorphism. After engraftment highly lung metastatic TC71-PM4 cells were injected intravenously. Mice were sacrificed 10 weeks after tumor cell injection. Hematoxylin-and-eosin staining was performed to identify lung metastatic foci. These tumors were then evaluated using immunohistochemical analysis. H-2Kb-positive cells were found in lung metastases but not in normal lung, liver or spleen tissues. Injection of CM-Dil-labeled BM cells into tumor bearing and control mice showed that nonspecific organ migration occurred at 24 h, but that these cells were absent 1 week later in control mice. These data suggest that the migration of the H-2Kb BM cells to lung nodules was specific because these cells were observed 14 weeks after transplantation. Co-localization of H-2Kb and CD31 or VE-Cadherin demonstrated that some endothelial cells were BM-derived. Co-localization of H-2Kb and Desmin, smooth muscle actin (α-SMA) or PDGFR-β indicated that a fraction of pericytes was also BM-derived. These results suggest that BM cells participate in the vascular formation that supports the growth of Ewing’s sarcoma lung metastases. BM cells migrated to the metastatic tumor and differentiated into endothelial cells and pericytes. These data indicated that targeting this process may have therapeutic potential.