Xiaofeng Wang, Ryan S Lee, Burak H Alver, Jeffrey R Haswell, Su Wang, Jakub Mieczkowski, Yotam Drier, Shawn M Gillespie, Tenley C Archer, Jennifer N Wu, Evgeni P Tzvetkov, Emma C Troisi, Scott L Pomeroy, Jaclyn A Biegel, Michael Y Tolstorukov, Bradley E Bernstein, Peter J Park, Charles W M Roberts
SMARCB1 (also known as SNF5, INI1, and BAF47), a core subunit of the SWI/SNF (BAF) chromatin-remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here we show that, despite having indistinguishable mutational landscapes, human rhabdoid tumors exhibit distinct enhancer H3K27ac signatures, which identify remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting-markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers...
February 2017: Nature Genetics