HDAC7 is a key factor for the germinal center reaction and its underexpression is associated with DLBCL prognosis

Histone deacetylase HDAC7 is required for early B cell development and governs the acquisition of B cell progenitors gene identity. Its role in mature B cell biology and associated malignancies is unknown. Here, by using a conditional mouse model for specific deletion in activated B cells, we demonstrate that HDAC7 is essential for the formation of germinal centers (GC). HDAC7 deficiency results in the generation of aberrant GCB cells, diminished class switch recombination (CSR) and plasma cell (PC) formation. We demonstrate that low expression of HDAC7 in diffuse large B cell lymphoma (DLBCL) tumors is associated with poor prognosis of the patients. Importantly, expression of HDAC7 in DLBCL cell lines reduces the proliferative capacity, as well as DLBCL tumorigenicity in vivo. In summary, our data revealed first, the important function of HDAC7 in the establishment of the GC, and second, the potential contribution of HDAC7 deregulation in DLBCL.