title: Genomic anatomy of the specific reciprocal translocation t(15;17) in acute promyelocytic leukemia.
abstract: 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.
authors.affiliation: III. Medizinische Universitätsklinik, Klinikum Mannheim, Fakultät für Klinische Medizin der Universität Heidelberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Reiter
authors.forename: Susanne
authors.initials: S
authors.lastname: Saussele
authors.forename: David
authors.initials: D
authors.lastname: Grimwade
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Wiemels
authors.forename: Mark R
authors.initials: MR
authors.lastname: Segal
authors.forename: Marina
authors.initials: M
authors.lastname: Lafage-Pochitaloff
authors.forename: Christoph
authors.initials: C
authors.lastname: Walz
authors.forename: Andreas
authors.initials: A
authors.lastname: Weisser
authors.forename: Andreas
authors.initials: A
authors.lastname: Hochhaus
authors.forename: Andreas
authors.initials: A
authors.lastname: Willer
authors.forename: Anja
authors.initials: A
authors.lastname: Reichert
authors.forename: Thomas
authors.initials: T
authors.lastname: Büchner
authors.forename: Eva
authors.initials: E
authors.lastname: Lengfelder
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Hehlmann
authors.forename: Nicholas C P
authors.initials: NC
authors.lastname: Cross
mesh_terms: 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*
chemical_list: 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