RESUMO
To identify and compare the features of stem like cells in human glioblastoma cell lines U251, U87MG, A172 with primary cultured glioblastoma stem cells, the ratio of CD133+ cells, the ability of tumor sphere formation, and self-renewing capacity of U251, U87MG, A172 cells in serum free medium plus EGF, bFGF and B27 supplement were detected. The results suggested that there might be more cancer stem like cells in U251 cells compared with others. CD133+ cells enriched in SP cells and in U251 cells cultured with the serum free medium. They expressed the neural stem cell markers CD133 and Nestin, but lacked of neuronal and astrocyte marker MAP2, beta-III tubulin and GFAP. They could apparently generate both neurons and glial cells after serum retrieved in vitro. Gli1, Bmi1, Notch2 and PTEN were also found expressed highly in them. Moreover, CD133+ cells were more resistant to hypoxia, irradiations and some chemotherapeutics than CD133-cells. So we suggested that glioblastoma stem like cells were existed in CD133+ cells in U251 cell line with characteristics of self-renew and generation of an unlimited progeny of non-tumorigenic cells. Molecular and functional characterization of such a tumorigenic population may be exploited in the development of novel cancer therapeutic drugs.
Assuntos
Diferenciação Celular , Proliferação de Células , Separação Celular , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Neuroglia/patologia , Neurônios/patologia , Antígeno AC133 , Animais , Antígenos CD/análise , Antineoplásicos/farmacologia , Hipóxia Celular , Linhagem Celular Tumoral , Feminino , Glioblastoma/imunologia , Glioblastoma/metabolismo , Glicoproteínas/análise , Humanos , Proteínas de Filamentos Intermediários/metabolismo , Camundongos , Camundongos SCID , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/efeitos da radiação , Proteínas do Tecido Nervoso/metabolismo , Nestina , Neuroglia/efeitos dos fármacos , Neuroglia/imunologia , Neuroglia/efeitos da radiação , Neurônios/efeitos dos fármacos , Neurônios/imunologia , Neurônios/metabolismo , Neurônios/efeitos da radiação , Proteínas Nucleares/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Peptídeos/análise , Complexo Repressor Polycomb 1 , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch2/metabolismo , Proteínas Repressoras/metabolismo , Esferoides Celulares , Células Tumorais CultivadasRESUMO
Gambogic acid, the major active ingredient of gamboge, has been shown to exhibit anti-cancer activity both in vivo and in vitro. However, its potential activity in tumor metastasis remains unclear. In the present study, we found that gambogic acid strongly inhibited the adhesion of highly metastatic mouse melanoma B16-F10 cells in vitro. Gambogic acid also exhibited significant anti-metastasis activity on the development of in vivo artificial metastases (i.e. following tail vein i.v. injection of the B16-F10 melanoma tumor cells in C57BL/6 mice). Flow cytometric analysis and Western blot showed that gambogic acid inhibited the cell surface expression of alpha(4) integrin, while exhibited negligible effects on the expression of alpha(5) and beta(1) integrin. Thus we concluded for the first time that gambogic acid could inhibit the adhesion and migration of B16-F10 cells in vitro and in vivo, in which down-regulation of alpha(4) integrin expression was involved.