title: Novel murine B-cell lymphoma/leukemia model to study BCL2-driven oncogenesis.
abstract: The BCL-2 family has been implicated in the pathogenesis of various hematopoietic malignancies, including follicular non-Hodgkin lymphoma and B-cell chronic lymphocytic leukemia. To identify genes that act synergistically in BCL2-enforced leukemogenesis, we developed a murine B-cell lymphoma/leukemia model based on the IL-3-dependent Balb/C pro-B line (FL5.12). FL5.12 cells were stably transfected with antiapoptotic BCL-2 alone or in combination with proapoptotic BAX or nonfunctional mutant BAX, thereby creating various levels of imbalance within the BCL-2 family. Transfectants were intravenously injected into normal Balb/C mice. Whereas FL5.12 cells did not provoke leukemia, mice injected with stable transfectants died of leukemia over time. Disease incidence and latency time depended on the degree of imbalance in the BCL-2 family, supporting a model whereby BCL2 drives tumorigenesis. All mice presented with hepatosplenomegaly and leukemic FL5.12 cells in peripheral blood and bone marrow compartments. Leukemic conversion was accompanied by secondary genetic aberrations leading to clonal IL-3-responsive leukemia. Cellular transformation was independent of alterations in c-Myc or downstream apoptotic pathway. Leukemic clones retained a normal DNA damage response leading to elevated P53 and P21 levels and cell cycle arrest upon irradiation. In conclusion, our mouse model may prove a valuable tool to identify genes that cooperate in BCL2-enforced lymphoma/leukemogenesis.
authors.affiliation: Department of Pediatrics, Division of Oncology/Hematology, Erasmus MC Rotterdam-Sophia Children's Hospital, NL-3015GE Rotterdam, The Netherlands. j.meijerink@erasmusmc.nl
authors.forename: Jules P P
authors.initials: JP
authors.lastname: Meijerink
authors.forename: Esther M M
authors.initials: EM
authors.lastname: Van Lieshout
authors.forename: H Berna
authors.initials: HB
authors.lastname: Beverloo
authors.forename: Ellen
authors.initials: E
authors.lastname: Van Drunen
authors.forename: Ewald J B M
authors.initials: EJ
authors.lastname: Mensink
authors.forename: Merryn
authors.initials: M
authors.lastname: Macville
authors.forename: Rob
authors.initials: R
authors.lastname: Pieters
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic; D004249:DNA Damage; D004195:Disease Models, Animal; D016158:Genes, p53; D006529:Hepatomegaly; D015448:Leukemia, B-Cell / Q000235:genetics* / Q000503:physiopathology* / Q000662:veterinary; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000503:physiopathology* / Q000662:veterinary; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000494:pharmacology*; D013163:Splenomegaly; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2