GSE172152
MOZ and Menin-MLL Complexes are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor [ChIP-seq and CUT&Tag]
Gastrointestinal stromal tumor (GIST) is commonly characterized by activating mutations in the receptor tyrosine kinase KIT. Tyrosine kinase inhibitors are the only approved therapy for GIST, and other complementary treatment strategies are urgently needed. As GIST both lacks oncogene amplification and relies upon an established network of transcription factors, we hypothesized that unique chromatin modifying enzymes are essential in orchestrating the GIST epigenome. Here, we identified through genome-wide CRISPR screening that MOZ and Menin-MLL chromatin regulatory complexes are cooperative and unique dependencies in GIST. These complexes were enriched at GIST-relevant genes and regulated their transcription. Inhibition of MOZ and Menin-MLL complexes decreased GIST cell proliferation by disrupting interactions with transcriptional regulators, such as DOT1L. Menin inhibition caused significant reductions in tumor burden in xenograft models, with superior effects observed in combination with imatinib. These results define unique chromatin regulatory dependencies in GIST and identify therapeutic strategies for clinical application. Overall design: ChIP-seq and CUT&Tag of GIST cell line GIST-T1