ChIP analysis of the levels of acetylated histones at the BRCA1 promoter following M344 and cisplatin treatments. A) MCF7 and B) A2780s cells treated with 5.0 μM M344 in combination with 2 μg/ml cisplatin for 24 hrs show reduced amounts of BRCA1 promoter DNA bound to acetylated histone 4 (AcH4). Real-time PCR products were run on a 1.6% agarose gel. "Input" controls: untreated; "No Ab" controls: incubation with agarose beads in the absence of αAcH4; and "αAcH4": incubation with agarose beads and αAcH4. The experiment was repeated twice with similar results.