title: [Effects of Bmi1 gene on endothelial cells promoting glioma stem cell-like phenotype].
abstract: OBJECTIVE
  To explore the effects of B-cell specific Maloney leukemia virus integration site 1 (Bmi1) gene on endothelial cells promoting glioma stem cell (GSC)-like phenotype.
  
  
  METHODS
  Glioblastoma cell line GL261 and brain micro-vessel endothelial cell line b.END3 were used. Transwell co-culture system, limit dilution assay, xenograft, real-time polymerase chain reaction (PCR), Western blot, fluorescence activating cell sorter (FACS) and gene knock-down assay were used to determine the GSC-like phenotype and Bmi1 gene expression in glioma cells.
  
  
  RESULTS
  Compared with the control of GL261 cell alone, (1) more and larger tumor spheres formed after co-culturing with endothelial cells (62.5% ± 1.5% vs 25.0% ± 4.6% at 40 cells/well, P = 0.000). Xenografts generated by GL261 cells with b.END3 cells appeared earlier and were larger than that by GL261 cells alone ((0.798 ± 0.297) cm(3) vs (0.362 ± 0.123) cm(3), P = 0.000); (2) CD133 positive glioma cells increased after co-culturing with endothelial cells (8.48% ± 0.78% vs 4.81% ± 0.37%, P = 0.000); (3) the expression of Bmi1 in co-cultured glioma cells was up-regulated at mRNA level (2.72 ± 0.18 vs 1.00 ± 0.15, P = 0.000) and at protein level; (4) the above phenomenon was attenuated when Bmi1 gene expression was inhibited by siRNA in glioma cells, CD133 positive portion of Bmi1-knockdown GL261 cells co-culturing with b.END3 cells decreased than that of wildtype GL261 cells (0.34% ± 0.21% vs 1.70% ± 0.69%, P = 0.025).
  
  
  CONCLUSIONS
  Endothelial cells promote GSC-like phenotype by up-regulating the expression of Bmi1 in glioma cells.
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Guang-ning
authors.initials: GN
authors.lastname: Yan
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: You-hong
authors.initials: YH
authors.lastname: Cui
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Xue-feng
authors.initials: XF
authors.lastname: Jiang
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Qing-liang
authors.initials: QL
authors.lastname: Wang
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China. Email: gdy007@tmmu.edu.cn.
authors.forename: De-yu
authors.initials: DY
authors.lastname: Guo
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology*; D005260:Female; D005910:Glioma / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D014411:Neoplastic Stem Cells / Q000166:cytology*; D010641:Phenotype; D063150:Polycomb Repressive Complex 1 / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*
chemical_list: C489421:Bmi1 protein, mouse; D011518:Proto-Oncogene Proteins; D063150:Polycomb Repressive Complex 1