Expression of Nanog in brain tumor stem cells

Abstract

Objective To detect the expression of Nanog in glioma cell line U87 and the relationship with BTSCs.Methods BTSCs were isolated from glioma cell line U87 and cultured in simplified serum-free neural stem cell medium by nanosphere suspension culture method spheres,and purified continuously through the monoclonal formation experiment.The immunofluorescence staining of cells was employed to identify the BTSCs and differentiated cells.The expression of Nanog mRNA was examined by RT- PCR and Nanog protein was detected by immunocytochemistry in U87 and BTSCs respectively.Double immunocytochemistry staining was used to detect the co- expressions of Nanog/CD133.Methods BTSCs were isolated ,cultured and purified successfully from glioma cell line U87.Both Nanog mRNA and protein were expressed in U87 and BTSCs.The expression rate of immunopositive cells was (64.1 ±18.2)% in U87 and (97.2±1.8)% in BTSCs respectively(t =5.719,P =0.000).The Nanog+/CD133+ cells could be found co-expressed in U87 and BTSCs by using double immunocytochemistry s taining.The relative level of Nanog expression was 0.3851 ±0.0771 in U87 and0.6032±0.1223 in BTSCs(t =4.770,P =0.000).Conclusion BTSCs exist in glioma cell line U87 in vitro.The levels of Nanog expression in BTSCs were higher than that in U87.Nanog expression was associated with the genesis and differentiation state of glioma.The overexpression of Nanog and co- expression of Nanog/CD133 showed that it might contribute to the existence of BTSCs,which lay a foundation to the further explore its role in biological behaviour of glioma.Expression of Nanog in U87 indicated the close relationship between glioma and stem cell,and suggested Nanog may play a critical role in the development of glioma. Key words: Glioma; Gene expression; Nanog; Cancer stem cell