Ibrutinib induces a global chromatin reorganisation in chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in developed countries. Ibrutinib (PCI-32765), a specific and irreversible inhibitor of Bruton's Tyrosine Kinase (BTK) represents a major step forward in the treatment of CLL. We have undertaken a detailed analysis of the changes happening to the chromatin structure in CLL cells from patients continuously receiving oral doses of ibrutinib. ChIP-seq has been performed for H3K4me3, H3K27ac, H3K27me3 and EZH2 . We observed that Ibrutinib-dependent lymphocytosis correlates with a global and transient recruitment of EZH2 to active cis-regulatory elements and increased H3K27me3.EGA study EGAS00001002827