Lifelong persistence of AML associated MLL partial tandem duplications (MLL-PTD) in healthy adults

Department of Hematology and Oncology, University of Goettingen, Goettingen, Germany.
Leukemia Research (Impact Factor: 2.69). 10/2006; 30(9):1091-6. DOI: 10.1016/j.leukres.2006.02.005
Source: PubMed

ABSTRACT AML-associated MLL-PTD contribute to leukemogenesis by a gain of function and confer an unfavorable prognosis. Like other leukemia associated aberrations they are also present in healthy adults. To delineate the leukemogenic mechanism we tracked down MLL-PTD in normal hematopoiesis and investigated cord blood samples. MLL-PTD were observed in 56/60 (93%) of all cord bloods. In contrast to AML, the transcript frequency in cord blood was four log scales lower as determined by real-time PCR. The CD34+ progenitor cell, CD33+ myeloid, CD19+ B-lymphoid and CD3+ T-lymphoid subfractions were positive. The ubiquitous presence of MLL-PTD in cord blood implicates a lifelong exposure, not an accumulation during lifetime. Since also present in the stem cell subfraction, these factors seem not to be major determinants in MLL-PTD leukemogenesis.

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