The Relation Of CD133+ Cell To Angiogenesis Of Glioma

Purpose:The morbidity of glioma occupies nearly 45%of all intracranial tumors in human beings.The chief therapy for glioma is the surgery,with the supplementary methods like radiotherapy,chemotherapy and immunotherapy etc.It plays a significant role in prolonging existence period,improving survival quality and achieving radical treatment that to omprove the postoperative therapeutic efficacy. Angiogenesis is critical to tumor formation and maintenance.Regulation of angiogenesis represents a complex process involving autocrine and paracrine growth factor loops with an interplay between tumor cells and the neovasculature.Malignant gliomas are highly lethal cancers dependent on angiogenesis.Improvements in the efficacy of these treatments will require advances in our understanding of the molecular mechanisms promoting glioblastoma angiogenesis.Recent studies of glioblastomas and other brain cancers identified tumor subpopulations that share characteristics with normal neural stem cells.Critical tumor subpopulations(cd133+ tumor cell)within gliomas share characteristics with neural stem cells.Stem cell- like glioma cells(SCLGC)express neural stem cell markers (including the cell-surface antigen prominin-1/cd133+),are capable of self-renewal, form neurosphere-like spheroids,and differentiate into multiple nervous system lineages.As angiogenesis represents a critical step in tumor formation(the angiogenic switch),We isolated cd133+ tumor cell from human glioblastoma specimen,we examined whether SCLGC contribute to tumor formation through promoting angiogenesisMethods: Patient biopsy specimens:Specimens from patients undergoing operation for newly diagnosed or recurrent glioblastoma were collected,Pathologic diagnosis was confirmed by Shan dong province hospital ?Tumors were sorted by magnetic cell sorting(MACS Separation),CD133+ and CD133- tumor cell populations were segregated by cell sorting.After short-term culture,10,000 cells were implanted into the right frontal lobes of athymic BALB/c nu/nu mice.Brains of euthanized mice were collected,fixed in formalin,paraffin embedded,and sectioned,or were frozen rapidly in liquid nitrogen for sections.Blood vessel density in frozen tumor sections was quantified as Weidner.Results and Conclusion:Isolate and culture tumor stem cell:Central nervous system neoplastic stem cells were defined through their phenotypic similarities to neural stem cells,we additionally generated short-term cultures from glioblastoma derived from human patient specimens that were maintained in immunocompromised mice in either s.c.or intracranial locations. Human specimens validate biological processes directly in patient cancers,whereas human glioma permit the purification of large numbers of viable tumor cells.The CD133 cell surface stem cell marker was used to select for a cell population enriched for SCLGC.We derived separate short-term cultures of CD133+ and CD133- tumor cells through tumor disaggregation,labeling with CD133 antibody,and FACS sorting. The CD133+ population was＞95%pure in repeated FACS analysis(data not shown). Tumors generated from CD133+ glioma population display increased tumor vascularity,necrosis,and hemorrhage.Tumorigenesis is dichotomized between the SCLGC and non- SCLGC populations To investigate the tumorigenic capacity of our glioma subpopulations, 10,000 CD 133_or CD 133+ glioma cells derived from multiple human glioblastoma patient specimens were implanted into the right frontal lobes of athymic nude mice. Every brain implanted with the CD133+ tumor cells displayed gross evidence of highly angiogenic and hemorrhagic tumors,in stark contrast to the brains implanted with CD133- tumor cells.Pathologic analysis of the brains implanted with CD133+ glioma cells showed large,highly proliferative and vascular tumors with widespread necrosis and hemorrhage.No mice implanted with CD133_-tumor cells from human specimens displayed evidence of brain tumor formation.Permit a comparison of vascularity between brains bearing CD133+ and CD133-.with MVD,we observed that tumors derived from CD133+ cells were markedly more vascular than tumors from CD133-tumor cells.Therefore,angiogenic potential is a critical difference between the in vivo tumor phenotypes of glioma SCLGC and non-SCLGC cells. Future treatment should target this small population of CD133 positive cancer stem cells in tumors to improve the survival of brain tumor patients.