Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis
<i>MLL1 (KMT2a)</i> gene rearrangements underlie the pathogenesis of aggressive MLL-driven acute leukemia. AF9, one of the most common MLL-fusion partners, recruits the histone H3K79 methyltransferase DOT1L to MLL target genes, constitutively activating transcription of pro-leukemic targ...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-02-01
|
| Series: | Cancers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6694/13/4/642 |
| _version_ | 1797414291786170368 |
|---|---|
| author | Sierrah M. Grigsby Ann Friedman Jennifer Chase Bridget Waas James Ropa Justin Serio Chenxi Shen Andrew G. Muntean Ivan Maillard Zaneta Nikolovska-Coleska |
| author_facet | Sierrah M. Grigsby Ann Friedman Jennifer Chase Bridget Waas James Ropa Justin Serio Chenxi Shen Andrew G. Muntean Ivan Maillard Zaneta Nikolovska-Coleska |
| author_sort | Sierrah M. Grigsby |
| collection | DOAJ |
| description | <i>MLL1 (KMT2a)</i> gene rearrangements underlie the pathogenesis of aggressive MLL-driven acute leukemia. AF9, one of the most common MLL-fusion partners, recruits the histone H3K79 methyltransferase DOT1L to MLL target genes, constitutively activating transcription of pro-leukemic targets. DOT1L has emerged as a therapeutic target in patients with MLL-driven leukemia. However, global DOT1L enzymatic inhibition may lead to off-target toxicities in non-leukemic cells that could decrease the therapeutic index of DOT1L inhibitors. To bypass this problem, we developed a novel approach targeting specific protein-protein interactions (PPIs) that mediate DOT1L recruitment to MLL target genes, and compared the effects of enzymatic and PPIs inhibition on leukemic and non-leukemic hematopoiesis. MLL-AF9 cell lines were engineered to carry mutant <i>DOT1L</i> constructs with a defective AF9 interaction site or lacking enzymatic activity. In cell lines expressing a <i>DOT1L</i> mutant with defective AF9 binding, we observed complete disruption of DOT1L recruitment to critical target genes and inhibition of leukemic cell growth. To evaluate the overall impact of DOT1L loss in non-leukemic hematopoiesis, we first assessed the impact of acute <i>Dot1l</i> inactivation in adult mouse bone marrow. We observed a rapid reduction in myeloid progenitor cell numbers within 7 days, followed by a loss of long-term hematopoietic stem cells. Furthermore, WT and PPI-deficient DOT1L mutants but not an enzymatically inactive DOT1L mutant were able to rescue sustained hematopoiesis. These data show that the AF9-DOT1L interaction is dispensable in non-leukemic hematopoiesis. Our findings support targeting of the MLL-AF9–DOT1L interaction as a promising therapeutic strategy that is selectively toxic to MLL-driven leukemic cells. |
| first_indexed | 2024-03-09T05:31:01Z |
| format | Article |
| id | doaj.art-2902658de0be4bd7b438c9d20bbfe636 |
| institution | Directory Open Access Journal |
| issn | 2072-6694 |
| language | English |
| last_indexed | 2024-03-09T05:31:01Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cancers |
| spelling | doaj.art-2902658de0be4bd7b438c9d20bbfe6362023-12-03T12:32:42ZengMDPI AGCancers2072-66942021-02-0113464210.3390/cancers13040642Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and HematopoiesisSierrah M. Grigsby0Ann Friedman1Jennifer Chase2Bridget Waas3James Ropa4Justin Serio5Chenxi Shen6Andrew G. Muntean7Ivan Maillard8Zaneta Nikolovska-Coleska9Molecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USADepartment of Internal Medicine, Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI 48104, USADepartment of Internal Medicine, Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI 48104, USADepartment of Internal Medicine, Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI 48104, USAMolecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USAMolecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USAMolecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USAMolecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USADepartment of Internal Medicine, Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI 48104, USAMolecular and Celular Graduate Program, Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48104, USA<i>MLL1 (KMT2a)</i> gene rearrangements underlie the pathogenesis of aggressive MLL-driven acute leukemia. AF9, one of the most common MLL-fusion partners, recruits the histone H3K79 methyltransferase DOT1L to MLL target genes, constitutively activating transcription of pro-leukemic targets. DOT1L has emerged as a therapeutic target in patients with MLL-driven leukemia. However, global DOT1L enzymatic inhibition may lead to off-target toxicities in non-leukemic cells that could decrease the therapeutic index of DOT1L inhibitors. To bypass this problem, we developed a novel approach targeting specific protein-protein interactions (PPIs) that mediate DOT1L recruitment to MLL target genes, and compared the effects of enzymatic and PPIs inhibition on leukemic and non-leukemic hematopoiesis. MLL-AF9 cell lines were engineered to carry mutant <i>DOT1L</i> constructs with a defective AF9 interaction site or lacking enzymatic activity. In cell lines expressing a <i>DOT1L</i> mutant with defective AF9 binding, we observed complete disruption of DOT1L recruitment to critical target genes and inhibition of leukemic cell growth. To evaluate the overall impact of DOT1L loss in non-leukemic hematopoiesis, we first assessed the impact of acute <i>Dot1l</i> inactivation in adult mouse bone marrow. We observed a rapid reduction in myeloid progenitor cell numbers within 7 days, followed by a loss of long-term hematopoietic stem cells. Furthermore, WT and PPI-deficient DOT1L mutants but not an enzymatically inactive DOT1L mutant were able to rescue sustained hematopoiesis. These data show that the AF9-DOT1L interaction is dispensable in non-leukemic hematopoiesis. Our findings support targeting of the MLL-AF9–DOT1L interaction as a promising therapeutic strategy that is selectively toxic to MLL-driven leukemic cells.https://www.mdpi.com/2072-6694/13/4/642Dot1lMLL-rearrangement leukemiaprotein-protein interactionhematopoiesis |
| spellingShingle | Sierrah M. Grigsby Ann Friedman Jennifer Chase Bridget Waas James Ropa Justin Serio Chenxi Shen Andrew G. Muntean Ivan Maillard Zaneta Nikolovska-Coleska Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis Cancers Dot1l MLL-rearrangement leukemia protein-protein interaction hematopoiesis |
| title | Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis |
| title_full | Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis |
| title_fullStr | Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis |
| title_full_unstemmed | Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis |
| title_short | Elucidating the Importance of DOT1L Recruitment in MLL-AF9 Leukemia and Hematopoiesis |
| title_sort | elucidating the importance of dot1l recruitment in mll af9 leukemia and hematopoiesis |
| topic | Dot1l MLL-rearrangement leukemia protein-protein interaction hematopoiesis |
| url | https://www.mdpi.com/2072-6694/13/4/642 |
| work_keys_str_mv | AT sierrahmgrigsby elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT annfriedman elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT jenniferchase elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT bridgetwaas elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT jamesropa elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT justinserio elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT chenxishen elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT andrewgmuntean elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT ivanmaillard elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis AT zanetanikolovskacoleska elucidatingtheimportanceofdot1lrecruitmentinmllaf9leukemiaandhematopoiesis |