[Phenotype of SHG-44 glioma stem cell spheres and pathological characteristics of their xenograft tumors].

Objective To study the phenotype and tumorigenicity of SHG-44 glioma stem cell spheres and the pathological characteristics of their xenograft tumors.Methods SHG-44 glioma cells were cultured under neural stem cell medium and glioma stem cell spheres were collected.Immunocytochemistry was used to dectet the expression of CD133,nestin,A2B5,vimentin,VEGFR-2 and IDH R132H.Cell spheres were induced using serum-containing medium,and the expression of CD133,nestin,vimentin,GFAP,β-Ⅲ tubulin and GalC in the cell spheres were detected.The expression of CD133,nestin,VEGFR-2,GFAP,S-100 and CD34 in the intracranial xenograft tumor tissues was detected using immunohistochemistry.The pathological characteristics of orthotopic xenograft tumors generated from the SHG-44 glioma cells and SHG-44 glioma stem cell spheres were compared.Results SHG-44 glioma stem cell spheres were collected successfully after cultured under neural stem cell medium.The ratio of CD133 + cells in the passage 10 SHG-44 glioma stem cell spheres was (71.63 ±5.92)％,significantly higher than that in the SHG-44 glioma cells [(1.95 ± 1.45) ％].Immunocytochemistry showed that in the SHG-44 glioma cell spheres,the ratio of nestin + cells was (84.06 ± 7.58) ％,vimentin + cells (29.11 ± 3.44) ％,VEGFR 2+ cells (64.44 ±3.69)％,and A2B5 + cells (14.08 ±2.19)％.A subpopulation of cells with mutation of IDH R132H was detected harboring in the SHG-44 glioma cell spheres.After induction of differentiation with serum-containing medium,the ratio of CD133 + cells was (1.89 ± 1.27)％,nestin + cells (6.67 ±2.75)％,vimentin+ cells (93.75 ±2.95)％,GFAP+ cells (91.33 ±4.75)％,β-Ⅲ tubulin+ cells (82.36 ± 4.02)％,and GalC+ cells (8.92 ± 3.19)％.Immunohistochemistry showed positive expression of GFAP,S-100,VEGFR-2,and negative of CD133 and nestin in the orthotopic xenograft tumors.A very small amount of human-specific CD34 cells formed a tubular structure.Compared with the SHG-44 glioma cell-formed xenograft tumor,the SHG-44 glioma stem cell-formed xenograft tumor exhibited a higher local invasiveness.Conclusions SHG-44 glioma cell spheres are successfully collected after cultured under neural stem cell medium.They belong to the CD133 + A2B5-GSC subpopulation,highly expressing VEGFR-2,possess the ability of both self-renewal and multi-directional differentiation,and may participate in the formation of vasculogenic mimicry. Key words: Glioma;  Tumor stem cell;  Cells, cultured;  Neoplasms transplantation; Nude mouse