Histological evidence of hypoxia-dependence of expression of NESP55 and of other genes in neuroblastoma xenografts.

Nuclear HIF2α immunoreactivity was used as operational definition of hypoxia. Serial sections were used to compare the different results.Abbreviations and symbols: IHC: immunohistochemistry; ISH: in situ hybridization; CgA: chromogranin A.⇑(sp): positivity specific for regions of chronic hypoxia.⇑(gr/w): weak positive gradient of expression in regions of chronic hypoxia but expression not specific to these regions.⇑*: few positive cells, but exclusively in regions of chronic hypoxia.ND: not analyzed.⇑(gr/str): strong positive gradient of expression in regions of chronic hypoxia but expression not specific to these regions.⇓(partial): partial down-regulation in regions of chronic hypoxia.⇓(complete): complete down-regulation in regions of chronic hypoxia. = : no discernible chronic hypoxia-dependence of expression intensity.⇑(ref): reference method for identification of regions of chronic hypoxia.