title: MLL leukemia induction by genome editing of human CD34+ hematopoietic cells.
abstract: Chromosomal rearrangements involving the mixed-lineage leukemia (MLL) gene occur in primary and treatment-related leukemias and confer a poor prognosis. Studies based primarily on mouse models have substantially advanced our understanding of MLL leukemia pathogenesis, but often use supraphysiological oncogene expression with uncertain implications for human leukemia. Genome editing using site-specific nucleases provides a powerful new technology for gene modification to potentially model human disease, however, this approach has not been used to re-create acute leukemia in human cells of origin comparable to disease observed in patients. We applied transcription activator-like effector nuclease-mediated genome editing to generate endogenous MLL-AF9 and MLL-ENL oncogenes through insertional mutagenesis in primary human hematopoietic stem and progenitor cells (HSPCs) derived from human umbilical cord blood. Engineered HSPCs displayed altered in vitro growth potentials and induced acute leukemias following transplantation in immunocompromised mice at a mean latency of 16 weeks. The leukemias displayed phenotypic and morphologic similarities with patient leukemia blasts including a subset with mixed phenotype, a distinctive feature seen in clinical disease. The leukemic blasts expressed an MLL-associated transcriptional program with elevated levels of crucial MLL target genes, displayed heightened sensitivity to DOT1L inhibition, and demonstrated increased oncogenic potential ex vivo and in secondary transplant assays. Thus, genome editing to create endogenous MLL oncogenes in primary human HSPCs faithfully models acute MLL-rearranged leukemia and provides an experimental platform for prospective studies of leukemia initiation and stem cell biology in a genetic subtype of poor prognosis leukemia.
authors: Department of Pathology.
authors: Corina
authors: C
authors: Buechele
authors: Division of Pediatric Hematology/Oncology, Department of Pediatrics.
authors: Erin H
authors: EH
authors: Breese
authors: Division of Blood and Marrow Transplantation, Department of Medicine, and.
authors: Dominik
authors: D
authors: Schneidawind
authors: Department of Pathology.
authors: Chiou-Hong
authors: CH
authors: Lin
authors: Department of Pathology.
authors: Johan
authors: J
authors: Jeong
authors: Department of Pathology.
authors: Jesus
authors: J
authors: Duque-Afonso
authors: Department of Pathology.
authors: Stephen H K
authors: SH
authors: Wong
authors: Department of Pathology.
authors: Kevin S
authors: KS
authors: Smith
authors: Division of Blood and Marrow Transplantation, Department of Medicine, and.
authors: Robert S
authors: RS
authors: Negrin
authors: Division of Stem Cell Transplantation and Regenerative Medicine, Department of Pediatrics, Stanford University, Stanford, CA.
authors: Matthew
authors: M
authors: Porteus
authors: Department of Pathology.
authors: Michael L
authors: ML
authors: Cleary
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000276:immunology; D002469:Cell Separation; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D004195:Disease Models, Animal; D055879:Gene Knock-In Techniques; D015894:Genome, Human; D006412:Hematopoietic Stem Cells; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics*; D006801:Humans; D015456:Leukemia, Biphenotypic, Acute / Q000235:genetics*; D051379:Mice; D018613:Microscopy, Confocal; D016297:Mutagenesis, Site-Directed; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D014161:Transduction, Genetic; D014162:Transfection
chemical_list: D018952:Antigens, CD34; C497422:KMT2A protein, human; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase