Automated CUT&Tag profiling of chromatin heterogeneity in mixed-lineage leukemia

Acute myeloid and lymphoid leukemias often harbor chromosomal translocations involving the Mixed Lineage Leukemia-1 gene, which encodes the KMT2A lysine methyltransferase. The most common translocations produce in-frame fusions of KMT2A to trans-activation domains of chromatin regulatory proteins. Here we develop a strategy to map the genome-wide occupancy of oncogenic KMT2A fusion proteins in primary patient samples regardless of fusion partner. By modifying the versatile CUT&Tag method for full automation we identify common and tumor-specific patterns of aberrant chromatin regulation induced by different KMT2A fusion proteins. Integration of automated and single-cell CUT&Tag uncovers lineage heterogeneity within patient samples and provides an attractive avenue for future diagnostics. We used Cleavage under targets and Tagmentation (Cut-and-Tag), a chromatin profiling strategy in which antibody-targeted controlled integration of DNA sequencing adapters produces libraries for paired-end DNA sequencing.