Hypoxia-induced tumour cell migration in an in vivo chicken model

To investigate the relationship between hypoxia, neovascularisation and tum our cell spread, experiments on the area vasculosa of the early chick embry o under different oxygen concentrations were performed in vivo. Human gliob lastoma cells (U-138MG) were inoculated onto the area vasculosa and the fer tilised eggs were incubated under conditions of normoxia or hypoxia. For ev aluation, we performed in vivo video-microscopy of the area vasculosa and d etermination of microvessel density (MVD), as well as a histological examin ation of the fixed specimen. Under hypoxia, MVD was significantly increased compared to normoxic conditions. Only under hypoxic conditions was tumour cell spread found outside the main tumour mass and with in the vessels, at times followed by the subsequent development of secondary tumour cell bulks on the area vasculosa, These data lead to the conclusion that hypoxia can stimulate tumour cell migration in this in vivo model. Copyright (C) 2001 S . Karger AG, Basel.