Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The t(11;20)(p15;q11) is a rare but recurrent translocation that so far has been described in only four acute myeloid leukemias (AMLs), two treatment-related myelodysplastic syndromes (t-MDSs), and one case of polycythemia vera. Recently, the t(11;20) was shown to result in a fusion of the NUP98 and TOP1 genes, with expression of the NUP98/TOP1 chimera encoded by the der(11)t(11;20), but not of the reciprocal TOP1/NUP98 on the der(20)t(11;20). The genomic breakpoints were subsequently mapped to introns 13 and 7 of NUP98 and TOP1, respectively. We present here a t-MDS with a three-way variant translocation, t(10;20;11)(q24;q11;p15), that generates a der(11)t(11;20) but not a der(20)t(11;20), strongly suggesting that the der(11) harbors the critical genetic rearrangement. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed a NUP98/TOP1 fusion in which exon 13 of NUP98 was fused in-frame with exon 8 of TOP1. Extra long (XL) genomic PCR and subsequent sequence analyses showed that the breakpoint in NUP98 occurred at nucleotide (nt) 3461 of intron 13, close to a MER (medium reiteration frequency interspersed repetitive element) repeat, and that the breakpoint in TOP1 was at nt 1436 of intron 7, downstream of a MIR (mammalian-wide interspersed repeats) repetitive element. Genomic XL PCR did not amplify the reciprocal TOP1/NUP98, nor was this chimera expressed, as expected from the cytogenetic finding. The present results provide further support for the involvement of the NUP98/TOP1 transcript, but not of the reciprocal one, in the development of MDS/AML. Furthermore, the three cases genomically characterized to date have all been treatment-related and have all harbored breakpoints in intron 13 of NUP98 and intron 7 of TOP1, suggesting that these introns are susceptible to chemotherapy-induced breakage.
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PMID:Expression of NUP98/TOP1, but not of TOP1/NUP98, in a treatment-related myelodysplastic syndrome with t(10;20;11)(q24;q11;p15). 1197 59

A rare chromosomal translocation, (11;20)(p15;q11), was detected in a 29-year-old male patient diagnosed with acute monocytic leukemia (AMoL) according to the French-American-British classification criteria. Whole chromosome painting analysis with paints for chromosomes 11 and 20 confirmed the result of conventional cytogenetic analysis. Reverse transcriptase polymerase chain reaction revealed the NUP98-TOP1 fusion transcript. To our knowledge, this is the second report of the translocation involving NUP98 and TOP1 genes in AMoL. On reviewing the literature, we suggest that t(11;20)(p15q11) is associated with myelocytic disorders rather than lymphocytic proliferative diseases.
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PMID:Generation of the NUP98-TOP1 fusion transcript by the t(11;20) (p15;q11) in a case of acute monocytic leukemia. 1264 54

A t(11;20)(p15;q11) is a rare but recurrent chromosomal aberration, reported in one case of polycythemia vera and a few cases of de novo acute myelocytic leukemia (AML) and therapy-related myelodysplastic syndrome (t-MDS). In t-MDS cases, the translocation resulted in the NUP98/TOP1 fusion transcript. The NUP98 gene has been suggested as the target for therapy-related malignancies. The reciprocal TOP1/NUP98 chimera, however, has not yet been encountered. We report a further case of de novo AML, subtype M2 in the French-American-British (FAB) classification, in which the reverse-transcriptase polymerase chain reaction (RT-PCR) revealed the NUP98/TOP1 chimera and also, for the first time, its reciprocal TOP1/NUP98. The literature review disclosed that, among six cases of de novo AML with t(11;20), the NUP98 gene was shown to be involved in one case and the NUP98/TOP1 chimera was detected in another. The translocation seems to be frequently associated with the FAB M2 subtype, younger age, hyperleukocytosis, and poor prognosis; thus, this translocation may identify a subset of not-therapy-related AML patients with shared clinical features.
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PMID:A t(11;20)(p15;q11) may identify a subset of nontherapy-related acute myelocytic leukemia. 1503 93