MicroRNA miR-125b causes leukemia.
MicroRNA miR-125b has been implicated in several kinds of leukemia. The chromosomal translocation t(2;11)(p21;q23) found in patients with myelodysplasia and acute myeloid leukemia leads to an overexpression of miR-125b of up to 90-fold normal. Moreover, miR-125b is also up-regulated in patients with B-cell acute lymphoblastic leukemia carrying the t(11;14)(q24;q32) translocation. To decipher the presumed oncogenic mechanism of miR-125b, we used transplantation experiments in mice. All mice transplanted with fetal liver cells ectopically expressing miR-125b showed an increase in white blood cell count, in particular in neutrophils and monocytes, associated with a macrocytic anemia. Among these mice, half died of B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia, or a myeloproliferative neoplasm, suggesting an important role for miR-125b in early hematopoiesis. Furthermore, coexpression of miR-125b and the BCR-ABL fusion gene in transplanted cells accelerated the development of leukemia in mice, compared with control mice expressing only BCR-ABL, suggesting that miR-125b confers a proliferative advantage to the leukemic cells. Thus, we show that overexpression of miR-125b is sufficient both to shorten the latency of BCR-ABL-induced leukemia and to independently induce leukemia in a mouse model.
Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
Marina
M
Bousquet
Marian H
MH
Harris
Beiyan
B
Zhou
Harvey F
HF
Lodish
D000818:Animals; D002471:Cell Transformation, Neoplastic; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000378:metabolism; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007938:Leukemia / Q000209:etiology* / Q000235:genetics*; D008099:Liver / Q000166:cytology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics*; D009368:Neoplasm Transplantation; D009857:Oncogenes
C531888:MIRN125 microRNA, human; D035683:MicroRNAs; D016044:Fusion Proteins, bcr-abl