Study Of VEGF In Directed Migration And Proliferation Of Human Brain Astroglioma Stem Cells

Objective To establish a method for isolation, culture and identification of human brainastroglioma stem cells (HBASCs)within glioma tissue in vitro. To investigate the effect ofvascular endothelial growth factor（VEGF）on the ability of directed migration andproliferation of human brain astroglioma stem cells(HBASCs), and to explore the possiblemechanism in it.Methods HBASCs were first sorted through Magnetic Activated Cell Sorting(MACS,immunomagnetic beads marking by CD133), cultured in serum-free neural stem cellmedium in vitro, and immunostained for stem cell markers(CD133and Nestin) anddifferentiated cell marker [glial acidic fibrillary protein(GFAP) and β-TubulinⅢ] foridentification, then transplanted into severe combined immunodeficiency mice(SCID mice)for tumorigenesis test. The expression of VEGFR of HBASCs was detected byimmunofluorescence staining. The protein expression of VEGF in normal and pathologicalbrain was examined by Western blot. The effect of VEGF on migration of HBASCs in vitrowas determined by Transwell. The effect of VEGF on proliferation of HBASCs wasexamined by Cell Counting Kit-8.Result Only a small population of astroglioma cells in fresh specimens of variouspathologic grade could generate tumor spheres and express CD133and Nestin. And thoseCD133+cells were obviously proliferative and could easily differentiate into tumor cellsexpressing β-TubulinⅢ and GFAP. After implant into SCID mice, CD133+astroglioma tumor spheres generated tumors that phenotypically resemble the tumor obtained frompatients. The expression of VEGFR in CD133+cells was over expressed. The expression ofVEGF in astroglioma was higher than that in normal tissue. VEGF induced directedmigration of HBASCs in a concentration-depended manner, which was abrogated byadding VEGF receptor antibodies. VEGF could also enhance the proliferation ability ofHBASCs mediated by VEGFR.Conclusion VEGFR was extensive expressed on CD133+astroglioma stem cells. VEGFexert a prominent influence on the ability of directed migration and proliferation ofHBASCs which may be modulated by VEGFR.