Genomic anatomy of the specific reciprocal translocation t(15;17) in acute promyelocytic leukemia.
The genomic breakpoints in the t(15;17)(q22;q21), associated with acute promyelocytic leukemia (APL), are known to occur within three different PML breakpoint cluster regions (bcr) on chromosome 15 and within RARA intron 2 on chromosome 17; however, the precise mechanism by which this translocation arises is unclear. To clarify this mechanism, we (i). assembled the sequence of RARA intron 2, (ii). amplified and sequenced the genomic PML-RARA junction sequences from 37 APL patients, and (iii). amplified and sequenced the reverse RARA-PML genomic fusion in 29 of these cases. Three significant breakpoint microclusters within RARA intron 2 were identified, suggesting that sequence-associated or structural factors play a role in the formation of the t(15;17). There was no evidence that the location of a breakpoint in PML had any relationship to the location of the corresponding breakpoint in RARA. Although some sequence motifs previously implicated in illegitimate recombinations were found in the microcluster regions, these associations were not significant. Comparison of forward and reverse genomic junctions revealed microhomologies, deletions, and/or duplications of either gene in all but one case, in which a complex rearrangement with inversion of the PML-derived sequence was found. These findings are consistent with the hypothesis that the t(15;17) occurs by nonhomologous recombination of DNA after processing of the double-strand breaks by a dysfunctional DNA damage-repair mechanism.
Reiter
Andreas
A
III. Medizinische Universitätsklinik, Klinikum Mannheim, Fakultät für Klinische Medizin der Universität Heidelberg, Germany.
Saussele
Susanne
S
Grimwade
David
D
Wiemels
Joseph L
JL
Segal
Mark R
MR
Lafage-Pochitaloff
Marina
M
Walz
Christoph
C
Weisser
Andreas
A
Hochhaus
Andreas
A
Willer
Andreas
A
Reichert
Anja
A
Büchner
Thomas
T
Lengfelder
Eva
E
Hehlmann
Rüdiger
R
Cross
Nicholas C P
NC
D019457:Chromosome Breakage / Q000235:genetics; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D003001:Cloning, Molecular; D020732:Cytogenetic Analysis / Q000379:methods; D006801:Humans; D007438:Introns / Q000235:genetics; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D016254:Mutagenesis, Insertional / Q000235:genetics; D009363:Neoplasm Proteins / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics; D000072482:Retinoic Acid Receptor alpha; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014178:Translocation, Genetic / Q000235:genetics*
D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein