Fig. 7

The influence of oxygen on pRCC cell growth. a Relative expression of hif1 and hif2 genes was measured in real-time PCR in relation to the PPIA housekeeping gene. Overexpression of hif1 was identified in Caki-2 and ACHN at various oxygen partial pressure compared to the control line (ASE). In hypoxia, hif1 expression was significantly downregulated in Caki-2 only. Relative expression of hif2 showed a different profile than hif1; hypoxia significantly downregulated the gene expression in Caki-2 and ASE, although in ACHN, a strong upregulation was observed. In both cases, hif1 and hif2 were not detectable in HKCSC. b Growth curves of cells cultured in monolayer in normoxic and hypoxic incubators were determined with alamarBlue® assay. The third day of culture was taken to statistical analysis because of the strategy for further experiments. In the observation of overall growth trends, hypoxia promoted proliferation of Caki-2 and ASE cell lines, and inhibited the proliferation of ACHN in a parallel lack of the influence on HKCSC. c The percentage of cells in different phases of the cell cycle was analyzed by flow cytometry with PI staining. The analysis revealed a significant influence of hypoxia on the G2/M arrest of ACHN, which correlated with the proliferation inhibition. In the case of Caki-2 cells, which proliferated more in low O₂, an increase in the percentage of cells in G2 phase was observed. For the rest of the cell lines, oxygen partial pressure had no effect on the cell cycle