title: Circulating endothelial progenitor cells are involved in VEGFR-2-related endothelial differentiation in glioma.
abstract: Endothelial progenitor cells (EPCs) play important roles in maintaining endothelial integrity and tumor vascularization. However, the differentiation of EPCs in the neoangiogenesis of gliomas has not yet been fully elucidated. The purpose in this study was to investigate the profile of EPC differentiation in rat C6 glioma using magnetic resonance imaging (MRI), a non-invasive monitoring assay. To achieve this goal, we isolated EPCs from rat bone marrow and identified them by detecting CD34, CD133, and VEGFR-2, the markers of EPCs. Coexpression of Ac-LDL and UEA-1 in EPCs was also determined. To dynamically monitor the migration of circulating cells, the EPCs were labeled with ultrasmall superparamagnetic iron oxide (USPIO) and injected by tail vein into rats bearing C6 glioma. MRI was performed at 24, 48, and 96 h after injection. The distribution and differentiation of EPCs were confirmed by histology. We found that the USPIO-labeled EPCs appeared at the tumor periphery where a large number of CD105-positive cells appeared at 24 h after injection by using MRI scanning. Ninety-six hours after injection, immunohistochemistry and Prussian blue staining were used to observe the labeled EPCs in the tumor tissue. We found that many of the labeled EPCs were overlapped with VEGFR-2-positive endothelial cells, but not CD105- or CD34-positive cells. These results suggest that EPCs can cross the blood-brain barrier from peripheral blood and home to tumors, where they differentiate into endothelial cells, including VEGFR-2-positive endothelial cells. MRI is a useful method for dynamically tracking the migration of USPIO-labeled EPCs.
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P.R. China.
authors.forename: Le
authors.initials: L
authors.lastname: Wang
authors.affiliation: Biopharmaceutical Research Institute, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.affiliation: Biopharmaceutical Research Institute, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
authors.forename: Qianfeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P.R. China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P.R. China.
authors.forename: Haibao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Biopharmaceutical Research Institute, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P.R. China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Li
authors.affiliation: Biopharmaceutical Research Institute, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Biopharmaceutical Research Institute, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
authors.forename: Yuxian
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P.R. China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D066026:Endothelial Progenitor Cells / Q000737:chemistry / Q000378:metabolism* / Q000637:transplantation; D005290:Ferric Compounds / Q000494:pharmacology; D005910:Glioma / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D040301:Vascular Endothelial Growth Factor Receptor-2