MOZ and Menin-MLL Complexes are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE172154 | GEO | 2022/05/02
REPOSITORIES: GEO
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Project description: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 complementary treatment strategies are urgently needed. As GIST 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. We identified through genome-scale 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/chromatin regulators, such as DOT1L. MOZ and Menin inhibition caused significant reductions in tumor burden in vivo, with superior effects observed with combined Menin and KIT inhibition. These results define unique chromatin regulatory dependencies in GIST and identify potential therapeutic strategies for clinical application.SignificanceAlthough many malignancies rely on oncogene amplification, GIST instead depends upon epigenetic regulation of KIT and other essential genes. Utilizing genome-scale CRISPR dependency screens, we identified complementary chromatin-modifying complexes essential to GIST and characterize the consequences of their disruption, elucidating a novel therapeutic approach to this disease. This article is highlighted in the In This Issue feature, p. 1599.
| S-EPMC9453853 | biostudies-literature
Project description: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.
2022-05-02 | GSE172153 | GEO
Project description: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.
2022-05-02 | GSE172152 | GEO
Project description:MOZ and Menin-MLL Complexes are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor
| PRJNA722244 | ENA
Project description:MOZ and Menin-MLL Complexes are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor [RNA-seq]
| PRJNA722253 | ENA
Project description:MOZ and Menin-MLL Complexes are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor [ChIP-seq and CUT&Tag]
| PRJNA722252 | ENA
Project description:Menin interacts with oncogenic MLL1-fusion proteins, and small molecules that disrupt these associations are in clinical trials for leukemia treatment. By integrating chromatin-focused and genome-wide CRISPR screens with genetic, pharmacologic, and biochemical approaches, we discovered a conserved molecular switch between the MLL1-Menin and MLL3/4-UTX chromatin-modifying complexes that dictates response to Menin-MLL inhibitors. MLL1-Menin safeguards leukemia survival by impeding the binding of the MLL3/4-UTX complex at a subset of target gene promoters. Disrupting the Menin-MLL1 interaction triggers UTX-dependent transcriptional activation of a tumor-suppressive program that dictates therapeutic responses in murine and human leukemia. Therapeutic reactivation of this program using CDK4/6 inhibitors mitigates treatment resistance in leukemia cells that are insensitive to Menin inhibitors. These findings shed light on novel functions of evolutionarily conserved epigenetic mediators like MLL1-Menin and MLL3/4-UTX and are relevant to understand and target molecular pathways determining therapeutic responses in ongoing clinical trials.SignificanceMenin-MLL inhibitors silence a canonical HOX- and MEIS1-dependent oncogenic gene expression program in leukemia. We discovered a parallel, noncanonical transcriptional program involving tumor suppressor genes that are repressed in Menin-MLL inhibitor-resistant leukemia cells but that can be reactivated upon combinatorial treatment with CDK4/6 inhibitors to augment therapy responses. This article is highlighted in the In This Issue feature, p. 1.
| S-EPMC9827117 | biostudies-literature
Project description:Translocations involving the mixed lineage leukemia (MLL) gene result in human acute leukemias with very poor prognosis. The leukemogenic activity of MLL fusion proteins is critically dependent on their direct interaction with menin, a product of the multiple endocrine neoplasia (MEN1) gene. Here we present what are to our knowledge the first small-molecule inhibitors of the menin-MLL fusion protein interaction that specifically bind menin with nanomolar affinities. These compounds effectively reverse MLL fusion protein-mediated leukemic transformation by downregulating the expression of target genes required for MLL fusion protein oncogenic activity. They also selectively block proliferation and induce both apoptosis and differentiation of leukemia cells harboring MLL translocations. Identification of these compounds provides a new tool for better understanding MLL-mediated leukemogenesis and represents a new approach for studying the role of menin as an oncogenic cofactor of MLL fusion proteins. Our findings also highlight a new therapeutic strategy for aggressive leukemias with MLL rearrangements.
| S-EPMC3401603 | biostudies-literature
Project description:Monocytic leukemia zinc finger protein (MOZ, MYST3, or KAT6A) is a MYST-type acetyltransferase involved in chromosomal translocation in acute myelogenous leukemia (AML) and myelodysplastic syndrome. MOZ is established as essential for hematopoiesis; however, the role of MOZ in AML has not been addressed. We propose that MOZ is critical for AML development induced by MLL-AF9, MLL-AF10, or MOZ-TIF2 fusions. Moz-deficient hematopoietic stem/progenitor cells (HSPCs) transduced with an MLL-AF10 fusion gene neither formed colonies in methylcellulose nor induced AML in mice. Moz-deficient HSPCs bearing MLL-AF9 also generated significantly reduced colony and cell numbers. Moz-deficient HSPCs expressing MOZ-TIF2 could form colonies in vitro but could not induce AML in mice. By contrast, Moz was dispensable for colony formation by HOXA9-transduced cells and AML development caused by HOXA9 and MEIS1, suggesting a specific requirement for MOZ in AML induced by MOZ/MLL fusions. Expression of the Hoxa9 and Meis1 genes was decreased in Moz-deficient MLL fusion-expressing cells, while expression of Meis1, but not Hoxa9, was reduced in Moz-deficient MOZ-TIF2 AML cells. AML development induced by MOZ-TIF2 was rescued by introducing Meis1 into Moz-deficient cells carrying MOZ-TIF2. Meis1 deletion impaired MOZ-TIF2-mediated AML development. Active histone modifications were also severely reduced at the Meis1 locus in Moz-deficient MOZ-TIF2 and MLL-AF9 AML cells. These results suggest that endogenous MOZ is critical for MOZ/MLL fusion-induced AML development and maintains active chromatin signatures at target gene loci.
| S-EPMC9577624 | biostudies-literature
Project description:AbstractRNA-binding proteins (RBPs) are emerging as a novel class of therapeutic targets in cancer, including in leukemia, given their important role in posttranscriptional gene regulation, and have the unexplored potential to be combined with existing therapies. The RBP insulin-like growth factor 2 messenger RNA-binding protein 3 (IGF2BP3) has been found to be a critical regulator of MLL-AF4 leukemogenesis and represents a promising therapeutic target. Here, we study the combined effects of targeting IGF2BP3 and menin-MLL interaction in MLL-AF4-driven leukemia in vitro and in vivo, using genetic inhibition with CRISPR-Cas9-mediated deletion of Igf2bp3 and pharmacologic inhibition of the menin-MLL interaction with multiple commercially available inhibitors. Depletion of Igf2bp3 sensitized MLL-AF4 leukemia to the effects of menin-MLL inhibition on cell growth and leukemic initiating cells in vitro. Mechanistically, we found that both Igf2bp3 depletion and menin-MLL inhibition led to increased differentiation in vitro and in vivo, seen in functional readouts and by gene expression analyses. IGF2BP3 knockdown had a greater effect on increasing survival and attenuating disease than pharmacologic menin-MLL inhibition with small molecule MI-503 alone and showed enhanced antileukemic effects in combination. Our work shows that IGF2BP3 is an oncogenic amplifier of MLL-AF4-mediated leukemogenesis and a potent therapeutic target, providing a paradigm for targeting leukemia at both the transcriptional and posttranscriptional level.
| S-EPMC10824693 | biostudies-literature