In:
Cancer Discovery, American Association for Cancer Research (AACR), Vol. 7, No. 1 ( 2017-01-01), p. 38-53
Kurzfassung:
Somatic mutations in CREBBP occur frequently in B-cell lymphoma. Here, we show that loss of CREBBP facilitates the development of germinal center (GC)–derived lymphomas in mice. In both human and murine lymphomas, CREBBP loss-of-function resulted in focal depletion of enhancer H3K27 acetylation and aberrant transcriptional silencing of genes that regulate B-cell signaling and immune responses, including class II MHC. Mechanistically, CREBBP-regulated enhancers are counter-regulated by the BCL6 transcriptional repressor in a complex with SMRT and HDAC3, which we found to bind extensively to MHC class II loci. HDAC3 loss-of-function rescued repression of these enhancers and corresponding genes, including MHC class II, and more profoundly suppressed CREBBP-mutant lymphomas in vitro and in vivo. Hence, CREBBP loss-of-function contributes to lymphomagenesis by enabling unopposed suppression of enhancers by BCL6/SMRT/HDAC3 complexes, suggesting HDAC3-targeted therapy as a precision approach for CREBBP-mutant lymphomas. Significance: Our findings establish the tumor suppressor function of CREBBP in GC lymphomas in which CREBBP mutations disable acetylation and result in unopposed deacetylation by BCL6/SMRT/HDAC3 complexes at enhancers of B-cell signaling and immune response genes. Hence, inhibition of HDAC3 can restore the enhancer histone acetylation and may serve as a targeted therapy for CREBBP-mutant lymphomas. Cancer Discov; 7(1); 38–53. ©2016 AACR. See related commentary by Höpken, p. 14. This article is highlighted in the In This Issue feature, p. 1
Materialart:
Online-Ressource
ISSN:
2159-8274
,
2159-8290
DOI:
10.1158/2159-8290.CD-16-0975
Sprache:
Englisch
Verlag:
American Association for Cancer Research (AACR)
Publikationsdatum:
2017
ZDB Id:
2607892-2
