Cr(VI) Promotes Differential Binding of CTCF to its Cognate Sites

Using ChIP-seq, we characterize the differential binding of CTCF following 48 hours of low-dose, Cr(VI) treatment. Differentially-bound sites are enriched in regions near genes that are actively transcribed in the basal state and strength of initial binding may be a factor in determining the directionality of binding affinity fluctuations. CTCF and cohesin samples were used to predict intra-TAD chromatin loops in an effort to provide an initial characterization of how Cr(VI) potentially disrupts chromatin-chromatin contacts important for the regulation of transcription, serving as a foundation for future studies. Examination of CTCF, cohesin, and five histone modifications in control and Cr(VI)-treated (1 µM) Hepa-1c1c7 cells using ChIP-seq.