Figure 5

Acetylation status of chromatin at four DNA sequences: c-myc ori, c-myc gene, β-globin ori and G-globin gene, upon treatment with cisplatin and butyrate . (A) Map of the human c-myc and β-globin loci. The positions of the origins of replication zones (replicators) are shown by solid lines and the genes are shown by arrows. The four sequence-tagged sites (STSs) amplified by PCR are designated as c-myc ori and c-myc gene and β-globin ori and G-globin gene and shown with vertical lines. (B) HeLa cells were treated with 8 μM cisplatin, with 5 mM butyrate, or with both and 4 h or 24 h after the treatment, chromatin was immunoprecipitated with anti-acetylated histone H4 antibody. Aliquots from the immunoprecipitated (ChIP) and input (Input) DNA were subjected to PCR using primers for the respective DNA sequences. The PCR products were separated on 2.5% agarose gels and stained with ethidium bromide. (C) The DNA fractions were scanned and quantified and the ratios ChIP/Input for the four sequences after the different treatments were shown. Results are means of three independent experiments and the standard deviations are shown with error bars.