Whole-genome GR binding sites and histone acetylation status in pediatric acute lymphoblastic leukemia patient-derived xenografts following dexamethasone treatment in vivo. Homo sapiens

Glucocorticoids are critical components of combination chemotherapy regimens in pediatric acute lymphoblastic leukemia (ALL). However, the signaling pathways regulating apoptosis in glucocorticoid-treated lymphoid cells remain unclear. In this study, pediatric ALL patient-derived xenograft inherently sensitive to glucocorticoids were exposed to dexamethasone in vivo. Whole-genome GR binding sites and histone acetylation status were detected using chromatin immunoprecipitation sequencing analyses. This provided a global understanding of dexamethasone-induced DNA modulations in ALL cells in vivo, which is likely to be important in the understanding of mechanisms of glucocorticoid response in lymphoid malignancies. Overall design: One xenograft (ALL-54) was derived from a patient of dexamethasone-good responder. The xenograft was innoculated into 2 NOD/SCID mice, and treated with dexamethasone (15 mg/kg) or vehicle control. Binding of glucocorticoid receptor (GR), histone acetylation and IgG control in spleen-harvest xenograft samples were detected using ChIP-seq.