Fig. 8

The influence of oxygen on gene expression. a Relative expression of cd105, cd133, oct4, and sox2 was measured by real-time PCR and presented as a fold change (hypoxia/normoxia). Both Caki-2 and ACHN cell lines had an increased expression of TF genes (oct4 and sox2) in hypoxia, similar to ASE. The expression of membrane marker genes (cd105 and cd133) was downregulated in Caki-2 and ASE by low O₂. The opposite phenomenon was obtained for cd105 and ACHN: hypoxia induced overexpression. Intriguingly, in HKCSC, none of the genes were detectable. b The percentage of CD105+ and CD133+ cells in tested cell lines was measured by flow cytometry and presented as a fold change (hypoxia/normoxia). Results from real-time PCR were confirmed for both proteins, and a reduced amount of the CD105+ and CD133+ populations in Caki-2 and ASE were observed in hypoxia. In contrast to gene expression, the CD105+ population was reduced in ACHN hypoxic cells