title: Ectopic expression of the homeobox gene Cdx2 is the transforming event in a mouse model of t(12;13)(p13;q12) acute myeloid leukemia.
abstract: Creation of fusion genes by balanced chromosomal translocations is one of the hallmarks of acute myeloid leukemia (AML) and is considered one of the key leukemogenic events in this disease. In t(12;13)(p13;q12) AML, ectopic expression of the homeobox gene CDX2 was detected in addition to expression of the ETV6-CDX2 fusion gene, generated by the chromosomal translocation. Here we show in a murine model of t(12;13)(p13;q12) AML that myeloid leukemogenesis is induced by the ectopic expression of CDX2 and not by the ETV6-CDX2 chimeric gene. Mice transplanted with bone marrow cells retrovirally engineered to express Cdx2 rapidly succumbed to fatal and transplantable AML. The transforming capacity of Cdx2 depended on an intact homeodomain and the N-terminal transactivation domain. Transplantation of bone marrow cells expressing ETV6-CDX2 failed to induce leukemia. Furthermore, coexpression of ETV6-CDX2 and Cdx2 in bone marrow cells did not accelerate the course of disease in transplanted mice compared to Cdx2 alone. These data demonstrate that activation of a protooncogene by a balanced chromosomal translocation can be the pivotal leukemogenic event in AML, characterized by the expression of a leukemia-specific fusion gene. Furthermore, these findings link protooncogene activation to myeloid leukemogenesis, an oncogenic mechanism so far associated mainly with lymphoid leukemias and lymphomas.
authors.affiliation: GSF-Clinical Cooperative Group Leukemia and Department of Medicine III, Grosshadern, Ludwig Maximilians University, 81377 Munich, Germany.
authors.forename: Vijay P S
authors.initials: VP
authors.lastname: Rawat
authors.forename: Monica
authors.initials: M
authors.lastname: Cusan
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Deshpande
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hiddemann
authors.forename: Leticia
authors.initials: L
authors.lastname: Quintanilla-Martinez
authors.forename: R Keith
authors.initials: RK
authors.lastname: Humphries
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Bohlander
authors.forename: Michaela
authors.initials: M
authors.lastname: Feuring-Buske
authors.forename: Christian
authors.initials: C
authors.lastname: Buske
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D000071616:CDX2 Transcription Factor; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics; D004195:Disease Models, Animal; D015870:Gene Expression; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D015534:Trans-Activators; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D000071616:CDX2 Transcription Factor; D018398:Homeodomain Proteins; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D015534:Trans-Activators; C117168:ETV6-CDX2 protein, human; D000097764:ETS Translocation Variant 6 Protein; C097899:homeobox protein HOXA9