Hypoxic changes in gene expression: effect of vhl and p53 genotype

Microarrray experiments were performed in order to identify genes whose expression is altered under hypoxic conditions and to determine whether these changes are dependant on the p53 and HIF tanscription factors. In order to determine HIF dependance, isogenic RCC4 cell lines were used that were either wildtype of null for vhl, the gene responsible for degrading HIF under normoxic conditions. In order to determine p53 dependance, isogenic HCT116 and H1299 cell lines that were wildtype or null for p53 were used. Gene expression was measured after exposure of cells in monolayer culture to hypoxia (<0.01% O2) for various times. Keywords: hypoxia, time course, genetic modification, cell line comparison Affymetrix genechips were used to measure expression in cells exposed to hypoxia in monolayer culture for different times. One replicate was analysed at each time point, except for the control (0 hr) and 18 hr time points in the RCC4 cells, where two independant replicates were performed.