Critically short telomeres in acute myeloid leukemia with loss or gain of parts of chromosomes.
Telomeres, nucleoprotein complexes at chromosome ends, protect chromosomes against end-to-end fusion. Previous in vitro studies in human fibroblast models indicated that telomere dysfunction results in chromosome instability. Loss of telomere function can result either from critical shortening of telomeric DNA or from loss of distinct telomere-capping proteins. It is less clear whether telomere dysfunction has an important role in human cancer development in vivo. Acute myeloid leukemia (AML) is a good model to study mechanisms that generate chromosome instability in human cancer development because distinct groups of AML are characterized either by aberrations that theoretically could result from telomere dysfunction (terminal deletions, gains/losses of chromosome parts, nonreciprocal translocations), or aberrations that are unlikely to result from telomere dysfunction (e.g., reciprocal translocations or inversions). Here we demonstrate that AML with multiple chromosome aberrations that theoretically could result from telomere dysfunction is invariably characterized by critically short telomeres. Short telomeres in this group are not associated with low telomerase activity or decreased expression of essential telomeric capping proteins TRF2 and POT1. In contrast, telomerase activity levels are significantly higher in AML with short telomeres. Notably, short telomeres in the presence of high telomerase may relate to significantly higher expression of TRF1, a negative regulator of telomere length. Our observations suggest that, consistent with previous in vitro fibroblast models, age-related critical telomere shortening may have a role in generating chromosome instability in human AML development.
Swiggers
Susan J J
SJ
Department of Hematology, Erasmus MC, Rotterdam, The Netherlands.
Kuijpers
Marianne A
MA
de Cort
Maartje J M
MJ
Beverloo
H Berna
HB
Zijlmans
J Mark J M
JM
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000473:pathology; D016922:Cellular Senescence; D002869:Chromosome Aberrations; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged; D009687:Nuclear Proteins / Q000378:metabolism; D000089804:Shelterin Complex; D035182:TATA Box Binding Protein-Like Proteins / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000235:genetics / Q000502:physiology*; D034501:Telomere-Binding Proteins / Q000378:metabolism; D035341:Telomeric Repeat Binding Protein 2; D014407:Tumor Cells, Cultured
D009687:Nuclear Proteins; C440849:POT1 protein, human; D000089804:Shelterin Complex; D035182:TATA Box Binding Protein-Like Proteins; C504753:TERF2 protein, human; D034501:Telomere-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2; D019098:Telomerase