Fig. 1From: Quantitative analysis of ChIP-seq data uncovers dynamic and sustained H3K4me3 and H3K27me3 modulation in cancer cells under hypoxiaValidation of sustained and dynamic H3K27me3 marking. Bioinformatic calling of enriched regions (gene tracks shown at left side for each locus) was validated by ChIP-PCR (bar plots; shown at right side for each locus) for a number of representative epigenetic profiles. Data for all time points are shown: normoxia (0), hypoxia 8 h (8), hypoxia 24 h (24) and reoxygenation (+8). Two regions used for normalization on chromosome 3 show sustained H3K27me3 enrichment (left panels); the CCNA2 locus is known to be free of H3K27me3 marking [24] (bottom panel); OPRL1, SLC9A5, APLN and LOX for genes that show dynamic modulation of H3K27me3 marking in relation to changes in oxygen pressure; gene-specific ChIP-PCR analyses are part of a biological study published elsewhere [10]. Diamond symbol indicates direction of transcription, black triangle indicates approximate position of primer set used for validation, and star symbol indicates a significant difference compared to t = 0 (i.e., normoxia; p < 0.05, Wilcoxon signed-rank test)Back to article page