title: MLL-ENL causes a reversible and myc-dependent block of myelomonocytic cell differentiation.
abstract: The translocation t(11;19) is a recurrent feature of a subgroup of acute leukemias occurring in infants. This event fuses the genes MLL and ENL and creates the leukemogenic oncoprotein MLL-ENL. We studied the effect of retroviral MLL-ENL expression in primary mouse hematopoietic cells and show here that MLL-ENL requires the oncoprotein Myc to establish a reversible differentiation arrest of a myelomonocytic precursor population. MLL-ENL-transduced cells proliferated as immature myeloid cells in the presence of interleukin 3. The addition of granulocyte colony-stimulating factor reversed the maturation block set by MLL-ENL and induced the development of mature granulocytes and macrophages accompanied by growth arrest. Gene expression analysis indicated a down-regulation of the proto-oncogene c-myc and of several c-myc target genes during granulocyte colony-stimulating factor-mediated differentiation. The role of c-myc in the MLL-ENL transformation pathway was tested by modulating the effective Myc protein concentrations in MLL-ENL transduced cells. Cotransduction of dominant-negative Myc neutralized the MLL-ENL effect and precluded transformation. In contrast, constitutive expression of Myc cooperated with MLL-ENL and caused the transformation of a cell population with an irreversible maturation arrest.
authors.affiliation: Department of Genetics, University Erlangen, 91058 Erlangen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schreiner
authors.forename: M
authors.initials: M
authors.lastname: Birke
authors.forename: M P
authors.initials: MP
authors.lastname: García-Cuéllar
authors.forename: O
authors.initials: O
authors.lastname: Zilles
authors.forename: J
authors.initials: J
authors.lastname: Greil
authors.forename: R K
authors.initials: RK
authors.lastname: Slany
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000473:pathology; D005786:Gene Expression Regulation; D016259:Genes, myc / Q000502:physiology*; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D007377:Interleukin-3 / Q000494:pharmacology; D007938:Leukemia / Q000235:genetics / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D051788:Myeloid-Lymphoid Leukemia Protein; D015514:Oncogene Proteins, Fusion / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000502:physiology; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic
chemical_list: D007377:Interleukin-3; C000715470:MAS1 protein, human; C425207:MLL-ENL oncoprotein, human; D015514:Oncogene Proteins, Fusion; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc; D016179:Granulocyte Colony-Stimulating Factor; D051788:Myeloid-Lymphoid Leukemia Protein