Supplementary Figure 1 shows NMR and biochemical data in support of LEDGF nucleosome binding specificity. Supplementary Figure 2 shows chromatin IP data indicating requirement for LEDGF in MLL target gene localization. Supplementary Figure 3 shows global and gene-specific chromatin localization of ASH1L. Supplementary Figure 4 shows quantitation of differentiation and apoptosis following ASH1L knockdown. Supplementary Figure 5 shows that over-expression of KDM2A interferes with MLL-mediated leukemic transformation phenotypes.
ARTICLE ABSTRACT
Numerous studies in multiple systems support that histone H3 lysine 36 dimethylation (H3K36me2) is associated with transcriptional activation; however, the underlying mechanisms are not well defined. Here, we show that the H3K36me2 chromatin mark written by the ASH1L histone methyltransferase is preferentially bound in vivo by LEDGF, a mixed-lineage leukemia (MLL)–associated protein that colocalizes with MLL, ASH1L, and H3K36me2 on chromatin genome wide. Furthermore, ASH1L facilitates recruitment of LEDGF and wild-type MLL proteins to chromatin at key leukemia target genes and is a crucial regulator of MLL-dependent transcription and leukemic transformation. Conversely, KDM2A, an H3K36me2 demethylase and Polycomb group silencing protein, antagonizes MLL-associated leukemogenesis. Our studies are the first to provide a basic mechanistic insight into epigenetic interactions wherein placement, interpretation, and removal of H3K36me2 contribute to the regulation of gene expression and MLL leukemia, and suggest ASH1L as a novel target for therapeutic intervention.Significance: Epigenetic regulators play vital roles in cancer pathogenesis and represent a new frontier in therapeutic targeting. Our studies provide basic mechanistic insight into the role of H3K36me2 in transcription activation and MLL leukemia pathogenesis and implicate ASH1L histone methyltransferase as a promising target for novel molecular therapy. Cancer Discov; 6(7); 770–83. ©2016 AACR.See related commentary by Balbach and Orkin, p. 700.This article is highlighted in the In This Issue feature, p. 681
