title: Potential role for DNA topoisomerase II poisons in the generation of t(11;20)(p15;q11) translocations.
abstract: Chromosomal aberrations are frequently associated with therapy-related myelodysplastic syndromes and acute myelogenous leukemia (t-MDS/AML) and are thought to result from exposure to genotoxic drugs, including alkylating agents and DNA topoisomerase II poisons. The NUP98 gene on chromosome band 11p15 is involved in several different chromosomal aberrations that have been associated with t-MDS/AML. We have cloned the translocation breakpoints from two cases of t-MDS harboring a t(11;20)(p15;q11). Sequence analysis of the breakpoints from both cases revealed almost perfectly balanced translocations between NUP98 and TOP1. There were no known recombinogenic sequences identified at or near the breakpoints. However, four bp microduplications present at the translocation crossover points suggested that these translocations may have been initiated by 4 bp staggered double-stranded DNA breaks, which are known to be associated with the action of topoisomerase II. Given the history of patient exposure to topoisomerase II poisons, and the fact that these drugs stabilize staggered breaks with a 4 bp overhang, it seems possible that drug-induced topoisomerase II cleavage and subunit exchange was involved in these translocations. These results suggest that NUP98 is a recurrent target for therapy-related malignancies induced by multiagent chemotherapy, and suggest a role for DNA topoisomerase II poisons in the generation of these translocations. Published 2000 Wiley-Liss, Inc.
authors.affiliation: Roswell Park Cancer Institute, Department of Medicine, Buffalo, New York.
authors.forename: H G
authors.initials: HG
authors.lastname: Ahuja
authors.forename: C A
authors.initials: CA
authors.lastname: Felix
authors.forename: P D
authors.initials: PD
authors.lastname: Aplan
mesh_terms: D000293:Adolescent; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001483:Base Sequence; D002675:Child, Preschool; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D003001:Cloning, Molecular; D004249:DNA Damage; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics; D059005:Topoisomerase II Inhibitors; D014178:Translocation, Genetic / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D008565:Membrane Proteins; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D059005:Topoisomerase II Inhibitors; C093350:nuclear pore complex protein 98; D004250:DNA Topoisomerases, Type II