- Email: [email protected]
Generation of the NUP98-TOP1 fusion transcript by the t(11;20) (p15;q11) in a case of acute monocytic leukemia
Cancer Genetics and Cytogenetics 140 (2003) 153–156
Short communication
Generation of the NUP98-TOP1 fusion transcript by the t(11;20) (p15;q11) in a case of acute monocytic leukemia Suning Chena, Yongquan Xuea,*, Zhong Chenb, Yu Guob, Yafang Wua, Jinlan Pana a
Leukemia Research Unit, Jiangsu Institute of Hematology, First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China b Division of Medical Genetics, Cytogenetics Laboratory, The University of Utah, Salt Lake City, UT, USA Received 25 April 2002; received in revised form 10 June 2002; accepted 11 June 2002
Abstract
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)(p15;q11) is associated with myelocytic disorders rather than lymphocytic proliferative diseases. © 2003 Elsevier Science Inc. All rights reserved.
1. Introduction The NUP98 gene localized to chromosome band 11p15 encodes a 98-kd component of the nuclear pore complex and appears to function as a docking protein involved in nucleocytoplasmic transport. This docking function is mediated, at least in part, by multiple FXFG repeats located in the N-terminal portion of the gene [1]. The NUP98 gene was first reported as a fusion gene with HOXA9 in de novo acute monocytic leukemia (AMoL) with the t(7;11)(p15; p15.5) [2,3]. This observation has led to the identification and cloning of at least eight different fusion transcripts encoding NUP98 fusion proteins. Of the chromosomal translocations involving 11p15, t(11;20)(p15;q11) has been reported in a small number of patients [4–8]. Recently, Ahuja et al. [8] demonstrated that the NUP98 gene was fused with TOP1 located on 20q11 in two therapy-related myelodysplastic syndrome (t-MDS) patients with the t(11;20)(p15;q11). Here we report a patient with AMoL (M5 subtype according to the French–American–British [FAB] classification criteria) accompanied by t(11;20)(p15;q11). Chromosome painting confirmed the existence of this translocation. Reverse transcriptase polymerase chain reaction (RT-PCR) using prim-
* Corresponding author. Tel.: 86-0512-5223637-8471; fax: 86512-5192662. E-mail address: mailto:[email protected] (Y. Xue).
ers derived from the sequences of NUP98 and TOP1 genes revealed the NUP98-TOP1 fusion transcript. 2. Materials and methods 2.1. Case report A 29-year-old male patient was admitted to our hospital in April 2001 because of fever and gingival swell and pain. He had no history of prior chemotherapy or radiation, or exposure to mutagenic agents. Physical examination disclosed pallor, tenderness of sternum, enlarged lymph nodes in the auxiliary region, and splenomegaly (3 cm below the left costal margin). At presentation, peripheral blood examination showed hemoglobin at a level of 68 g/L, a white blood cell count of 331.2 109/L and platelets at a level of 56 109/L. Bone marrow aspiration was markedly hypercellular with 40.5% monoblasts and 27% promonocytes, which had folded nuclei, invisible nucleoli, and finely reticular chromatin with abundant blue-gray cytoplasm and fine azurophilic granules in the cytoplasm. No obvious dysplastic changes involving trilineages were observed. Eighty percent of the leukemic cells were negative for peroxidase staining. Flow cytometry analysis revealed that the leukemic cells were positive for CD2 (76.8%), CD7 (40.1%), CD13 (63.4%), CD33 (95.0%), and CD34 (54.3%), but negative for CD10, CD19, CD20, and CD14. He was diagnosed as having AMoL (M5b according to the
0165-4608/03/$ – see front matter © 2003 Elsevier Science Inc. All rights reserved. PII: S0165-4608(02)00 6 4 2 - 8
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S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
FAB criteria). He received leukapheresis therapy to reduce the amount of leukemic cells in the peripheral blood. Then he was treated with a cycle of DA (daunorubicin 60 mg/day for 3 days, cytosine arabinoside 150 mg/day for 7 days) regimen. On day 12 after induction chemotherapy, he died of intracranial hemorrhage. 2.2. Cytogenetic study Chromosomal study was performed on bone marrow cells at presentation. Samples were processed using standard 24-hour unstimulated cultures. R-bands by heating using Giemsa (RHG banding) was used for karyotypic analysis. Clonal karyotypic abnormalities were identified according to the International System for Human Cytogenetic Nomenclature (ISCN 1995) [9].
using 10-pmol primers NUP98-A1 (5-CAGCCAC TTTGGGCTTTGG-3) and TOP1-B1 (5-GGGGCTCAG CTTCATGACT-3), 200 M dNTPs, 1.5 mM MgCl2, and 0.3U Taq DNA polymerase in a total reaction volume of 50 L. After an initial denaturation of 10 minutes at 95C, 35 cycles of 1 minute at 95C, 1 minute at 60C, and 1 minute at 72C, followed by a final extension at 72C for 10 minutes were performed in a Geneamp PCR systems 2400 (Perking Elmer Cetus, Norwalk, CT, USA). The PCR products were analyzed on 2% agarose gels. An aliquot of cDNA reagents of a normal individual was amplified by PCR as a negative control meantime. -2 microglobulin was amplified as internal control. 3. Results
2.3. Chromosome painting analysis
3.1. Cytogenetic study
Chromosome painting was performed using whole chromosome paints (WCP) for chromosomes 11 and 20 labeled with fluorescein (FITC) and TexasRed, respectively. Its procedures followed the manufacturer’s instructions (Vysis, Downers Grove, IL, USA).
A total of 10 metaphases were evaluated, and in all of them we found that the dark band located on the terminal of the short arm of an abnormal chromosome 11 was wider than that on its homologue, but the long arm of one chromosome 20 was deleted with a breakpoint at q11, suggesting a translocation between chromosomes 11 and 20. Thus, the karyotype may be described as follows: 46,XY,t(11;20)(p15;q11)[10]. A representative karyotype is illustrated in Fig. 1.
2.4. RT-PCR assay Total cellular RNA was isolated with Trizol reagents according to the manufacturer’s instructions (GIBCO BRL, Gaithersburg, MD, USA). Following cDNA synthesis with RT of Molony Murine Leukemia Virus (GIBCO BRL), aliquots of 3 L of cDNA was subjected to PCR amplification
3.2. Chromosome painting analysis Chromosome painting analysis with WCP 11 and 20 detected a red fluorescent signal on the terminal portion of the
Fig. 1. A representative R-banded karyotype from a bone marrow cell showing 46,XY,t(11;20)(p15;q11).
S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
short arm of one chromosome 11 which showed a green fluorescent signal, whereas no green fluorescent signal was detected on the terminal of one chromosome 20 with shorter red fluorescent signal than its homologue because the translocation segment from chromosome 11p was too small to be detected by WCP 11 (Fig. 2). This finding indicated the translocation between chromosomes 11 and 20. 3.3. RT-PCR RT-PCR detected a 420-bp band corresponding to NUP98-TOP1 fusion transcript in this patient, while a normal individual had a negative result (Fig. 3A). Sequence analysis showed that the 420-bp PCR product was generated by fusion of NUP98 to TOP1, which was consistent with the results of Ahuja et al. [8] (Fig. 3B). 4. Discussion Recently, a number of laboratories have reported different translocations that involved the NUP98 gene located on 11p15.5 in various hematologic malignancies. At least eight different fusion partners of the NUP98 gene have been cloned such as PMX1 in t(1;11)(q23;p15.5) seen in patients with t-MDS/AMoL [10]; HOXD13 in t(2;11)(q31;p15.5) in patients with de novo AMoL and t-MDS/AMoL [11]; RAP1GDS1 in t(4;11)(q21;p15.5) in patients with t-acute lymphocytic leukemia [12]; NSD1 in t(5;11)(q35;p15.5) in patients with AMoL [13]; HOXA9 in t(7;11)(p15;p15.5) in patients with AMoL, MDS, tMDS/AMoL, and chronic myelogenous leukemia [2,3]; LEDGF in t(9;11)(p22;p15.5) in patients with AMoL [14]; and DDX10 in inv(11)(p15q22) in patients with AMoL and t-MDS/AMoL [15]. The first case with t(11;20)(p15;q11) was reported in a patient with polycythemia vera (PV) in 1972 [4]. Mitelman et al. [5] and Betts et al. [6] reported three AMoL-M2 pa-
155
tients with this translocation. Then Ahuja et al. [8] demonstrated that TOP1 on 20q11 was the partner of NUP98 gene in this translocation in two t-MDS patients. Recently, Kakazu et al. [7] reported an AMoL-M5b patient with t(11;20) (p15;q11.2). Fluorescence in situ hybridization (FISH) analysis using a probe for the NUP98 gene showed that the NUP98 gene was involved in this patient. But they could not investigate the genomic rearrangement of the TOP1 or detect NUP98-TOP1 fusion transcript because high molecular weight DNA or RNA could not be obtained [7]. Here we presented another AMoL-M5b patient with a t(11;20)(p15;q11). Conventional cytogenetic analysis and chromosome painting using WCP 11 and 20 demonstrated the existence of this translocation. Moreover, NUP98-TOP1 fusion transcript was detected by RT-PCR. In view of the fact that t(11;20) has been found in various myelocytic disorders including PV, MDS, and AMoL, whereas lymphocytic proliferative diseases with t(11;20) have not been reported thus far, we consider that this translocation is associated with myelocytic disorder rather than lymphocytic proliferative diseases. As the chromosome segment involved in this translocation is small, it may be difficult to detect by cytogenetics alone. RT-PCR and/or FISH may be more reliable methods for the detection of this abnormality. The patients with t(11;20)(p15;q11) may be associated with a poor prognosis because two AMoL-M2 patients described by Mitelman et al. [5] showed partial or no response to induction
Fig. 3. (Above) The results of RT-PCR showing a 420-bp band corresponding to NUP98-TOP1 fusion product in the present case (lane 1: a healthy person as negative control; lane 2: present case; and M: pUC19 DNA/MspI (HpaI) marker (MBI Fermentas). (Below) The sequences around the breakpoints of the NUP98 and TOP1 genes and the NUP98-TOP1 sequence. Boldface represents the sequence derived from the TOP1 gene. NUP98: 5-ATGTCAGACCCTAAGAAGAAGGAAGAGAGATTGAAACCAAC AAATCCAGCAGCC-3 MSDPLLLEERLKPTNPAA
Fig. 2. Chromosome painting analysis demonstrating a red fluorescent signal on the terminal portion of the short arm of chromosome 11 with a green fluorescent signal, while no green fluorescent signal was seen on the terminal of one chromosome 20 with shorter red fluorescent signal than its homologue.
NUP98-TOP1: 5-ATGTCAGACCCTAAGAAGAAGGAAGAGGATGGTAAATTGAA AAAACCCAAGAAT-3 MSDPLLLEEDGKLKKPKN TOP1: 5-AGAAAAAGAAAACTAGAAGAAGAAGAGGATGGTAAATTGAA AAAACCCAAGAAT-3 RKRKLEEEEDGKLKKPKN
156
S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
chemotherapy, and in an AML-M5b patient reported by Kakazu et al. [7], the leukemia relapsed in one year. As for our patient, he was treated with one course of DA regimen and died of intracranial hemorrhage on day 12 after chemotherapy. Thus, we cannot evaluate the effectiveness of chemotherapy. The number of cases with t(11;20)p15;q11) reported so far is too small to draw firm conclusions about the prognosis of the diseases with this translocation. Thus, it is necessary to accumulate more data on patients with t(11;20)(p15;q11).
[7]
[8]
[9] [10]
References [1] Radu A, Moore MS, Blobel G. The peptide repeat domain of nucleoporin NUP98 functions as a docking site in transport across the nuclear pore complex. Cell 1995;81:215–22. [2] Nakamura T, Largaespada DA, Lee MP, Johnson LA, Ohyashiki K, Toyama K, Chen SJ, Willman CL, Chen IM, Feinberg AP, Jenkins NA, Copeland NG, Shaughnessy JD. Fusion of nucleoporin gene NUP98 to HOXA9 by the chromosome translocation t(7;11)(p15; p15) in human myeloid leukaemia. Nat Genet 1996;12:154–8. [3] Borrow J, Shearman AM, Stanton VP, Becher R, Collins T, Williams AJ, Dube I, Katz F, Kwong YL, Morris C, Ohyashiki K, Toyama K, Rowley J, Housman DE. The t(7;11)(p15;p15) translocation in acute myeloid leukaemia fuses the gene for nucleoporin NUP98 and class I homeoprotein HOXA9. Nat Genet 1996;12:159–67. [4] Berger R. Translocation t(11;20) et polyglobulic primitive. [abstract] Nouv Presse Med 1972;4:1975. [5] Mitelman F, Prigogina EL, Fleischman EW, Frenkel MA, Garwicz S, Heim S, Ilyinskaya GW, Kristoffersson V, Mandahl N, Volkova, MA. A new-specific chromosomal rearrangement t(11;20)(p15;q11) in myeloblastic leukemia with maturation. Leukemia 1988;2:430–2. [6] Betts DR, Greiner J, Feldges A, Niggli FK. A further case of a t(11;
[11]
[12]
[13]
[14]
[15]
20)(p15;q11.2) translocation in an acute myeloid leukemia (FAB M2). J Pediatr Hematol Oncol 1998;20:91–3. Kakazu N, Shinzato I, Arai Y, Gotoh S, Matsushita A, Ishikawa T, Nagai K, Takahashi T, Ohno T, Tsuchiya T, Ohki M, Abe T. Involvement of the NUP98 gene in a chromosomal translocation t(11;20) (p15;q11.2) in a patient with acute monocytic leukemia (FAB-M5b). Int J Hematol 2001;74:53. Ahuja H, Felix CA, Aplan PD. The t(11;20)(p15;q11) chromosomal translocation associated with therapy-related myelodysplastic syndrome results in an NUP98–TOP1 fusion. Blood 1999;94:3258–61. ISCN. An international system for human cytogenetic nomenclature. Mitelman F, editor. Basel: S. Karger, 1995. Nakamura T, Yamazaki Y, Hatano Y, Miura I. NUP98 is fused to PMX1 homeobox gene in human acute myelogenous leukemia with chromosome translocation t(1;11)(q23;p15). Blood 1999;94:741–7. Raza-Egilmez SZ, Jani-Sait SN, Grossi M, Higgins MJ, Shows TB, Aplan PD. NUP98-HOXD13 gene fusion in therapy-related acute myelogenous leukemia. Cancer Res 1998;58:4269–73. Hussey DJ, Nicola M, Moore S, Peters GB, Dobrovic A. The t(4; 11)(q21;p15) translocation fuses the NUP98 and RAP1GDS1 genes and is recurrent in T-cell acute lymphocytic leukemia. Blood 1999; 94:2072–9. Jaju RJ, Fidler C, Haas OA, Strickson AJ, Watkins F, Clark K, Cross NC, Cheng JF, Aplan PD, Kearney L, Boultwood J, Wainscoat JS. A novel gene, NSD1, is fused to NUP98 in the t(5;11)(q35;p15.5) in de novo childhood acute myeloid leukemia. Blood 2001;98:1264–7. Ahuja HG, Hong J, Aplan PD, Tcheurekdjian L, Forman SJ, Slovak ML. t(9;11)(p22;p15) in acute myeloid leukemia results in a fusion between NUP98 and the gene encoding transcriptional coactivators p52 and p75-lens epithelium-derived growth factor (LEDGF). Cancer Res 2000;60:6227–9. Arai Y, Hosoda F, Kobayashi H, Arai K, Hayashi Y, Kamada N, Kaneko Y, Ohli M. The inv(11)(p15q22) chromosome translocation of de novo and therapy-related myeloid malignancies results in fusion of the nucleoporin gene, NUP98, with the putative RNA helicase gene, DDX10. Blood 1999;89:3936–44.
Short communication
Generation of the NUP98-TOP1 fusion transcript by the t(11;20) (p15;q11) in a case of acute monocytic leukemia Suning Chena, Yongquan Xuea,*, Zhong Chenb, Yu Guob, Yafang Wua, Jinlan Pana a
Leukemia Research Unit, Jiangsu Institute of Hematology, First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China b Division of Medical Genetics, Cytogenetics Laboratory, The University of Utah, Salt Lake City, UT, USA Received 25 April 2002; received in revised form 10 June 2002; accepted 11 June 2002
Abstract
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)(p15;q11) is associated with myelocytic disorders rather than lymphocytic proliferative diseases. © 2003 Elsevier Science Inc. All rights reserved.
1. Introduction The NUP98 gene localized to chromosome band 11p15 encodes a 98-kd component of the nuclear pore complex and appears to function as a docking protein involved in nucleocytoplasmic transport. This docking function is mediated, at least in part, by multiple FXFG repeats located in the N-terminal portion of the gene [1]. The NUP98 gene was first reported as a fusion gene with HOXA9 in de novo acute monocytic leukemia (AMoL) with the t(7;11)(p15; p15.5) [2,3]. This observation has led to the identification and cloning of at least eight different fusion transcripts encoding NUP98 fusion proteins. Of the chromosomal translocations involving 11p15, t(11;20)(p15;q11) has been reported in a small number of patients [4–8]. Recently, Ahuja et al. [8] demonstrated that the NUP98 gene was fused with TOP1 located on 20q11 in two therapy-related myelodysplastic syndrome (t-MDS) patients with the t(11;20)(p15;q11). Here we report a patient with AMoL (M5 subtype according to the French–American–British [FAB] classification criteria) accompanied by t(11;20)(p15;q11). Chromosome painting confirmed the existence of this translocation. Reverse transcriptase polymerase chain reaction (RT-PCR) using prim-
* Corresponding author. Tel.: 86-0512-5223637-8471; fax: 86512-5192662. E-mail address: mailto:[email protected] (Y. Xue).
ers derived from the sequences of NUP98 and TOP1 genes revealed the NUP98-TOP1 fusion transcript. 2. Materials and methods 2.1. Case report A 29-year-old male patient was admitted to our hospital in April 2001 because of fever and gingival swell and pain. He had no history of prior chemotherapy or radiation, or exposure to mutagenic agents. Physical examination disclosed pallor, tenderness of sternum, enlarged lymph nodes in the auxiliary region, and splenomegaly (3 cm below the left costal margin). At presentation, peripheral blood examination showed hemoglobin at a level of 68 g/L, a white blood cell count of 331.2 109/L and platelets at a level of 56 109/L. Bone marrow aspiration was markedly hypercellular with 40.5% monoblasts and 27% promonocytes, which had folded nuclei, invisible nucleoli, and finely reticular chromatin with abundant blue-gray cytoplasm and fine azurophilic granules in the cytoplasm. No obvious dysplastic changes involving trilineages were observed. Eighty percent of the leukemic cells were negative for peroxidase staining. Flow cytometry analysis revealed that the leukemic cells were positive for CD2 (76.8%), CD7 (40.1%), CD13 (63.4%), CD33 (95.0%), and CD34 (54.3%), but negative for CD10, CD19, CD20, and CD14. He was diagnosed as having AMoL (M5b according to the
0165-4608/03/$ – see front matter © 2003 Elsevier Science Inc. All rights reserved. PII: S0165-4608(02)00 6 4 2 - 8
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S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
FAB criteria). He received leukapheresis therapy to reduce the amount of leukemic cells in the peripheral blood. Then he was treated with a cycle of DA (daunorubicin 60 mg/day for 3 days, cytosine arabinoside 150 mg/day for 7 days) regimen. On day 12 after induction chemotherapy, he died of intracranial hemorrhage. 2.2. Cytogenetic study Chromosomal study was performed on bone marrow cells at presentation. Samples were processed using standard 24-hour unstimulated cultures. R-bands by heating using Giemsa (RHG banding) was used for karyotypic analysis. Clonal karyotypic abnormalities were identified according to the International System for Human Cytogenetic Nomenclature (ISCN 1995) [9].
using 10-pmol primers NUP98-A1 (5-CAGCCAC TTTGGGCTTTGG-3) and TOP1-B1 (5-GGGGCTCAG CTTCATGACT-3), 200 M dNTPs, 1.5 mM MgCl2, and 0.3U Taq DNA polymerase in a total reaction volume of 50 L. After an initial denaturation of 10 minutes at 95C, 35 cycles of 1 minute at 95C, 1 minute at 60C, and 1 minute at 72C, followed by a final extension at 72C for 10 minutes were performed in a Geneamp PCR systems 2400 (Perking Elmer Cetus, Norwalk, CT, USA). The PCR products were analyzed on 2% agarose gels. An aliquot of cDNA reagents of a normal individual was amplified by PCR as a negative control meantime. -2 microglobulin was amplified as internal control. 3. Results
2.3. Chromosome painting analysis
3.1. Cytogenetic study
Chromosome painting was performed using whole chromosome paints (WCP) for chromosomes 11 and 20 labeled with fluorescein (FITC) and TexasRed, respectively. Its procedures followed the manufacturer’s instructions (Vysis, Downers Grove, IL, USA).
A total of 10 metaphases were evaluated, and in all of them we found that the dark band located on the terminal of the short arm of an abnormal chromosome 11 was wider than that on its homologue, but the long arm of one chromosome 20 was deleted with a breakpoint at q11, suggesting a translocation between chromosomes 11 and 20. Thus, the karyotype may be described as follows: 46,XY,t(11;20)(p15;q11)[10]. A representative karyotype is illustrated in Fig. 1.
2.4. RT-PCR assay Total cellular RNA was isolated with Trizol reagents according to the manufacturer’s instructions (GIBCO BRL, Gaithersburg, MD, USA). Following cDNA synthesis with RT of Molony Murine Leukemia Virus (GIBCO BRL), aliquots of 3 L of cDNA was subjected to PCR amplification
3.2. Chromosome painting analysis Chromosome painting analysis with WCP 11 and 20 detected a red fluorescent signal on the terminal portion of the
Fig. 1. A representative R-banded karyotype from a bone marrow cell showing 46,XY,t(11;20)(p15;q11).
S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
short arm of one chromosome 11 which showed a green fluorescent signal, whereas no green fluorescent signal was detected on the terminal of one chromosome 20 with shorter red fluorescent signal than its homologue because the translocation segment from chromosome 11p was too small to be detected by WCP 11 (Fig. 2). This finding indicated the translocation between chromosomes 11 and 20. 3.3. RT-PCR RT-PCR detected a 420-bp band corresponding to NUP98-TOP1 fusion transcript in this patient, while a normal individual had a negative result (Fig. 3A). Sequence analysis showed that the 420-bp PCR product was generated by fusion of NUP98 to TOP1, which was consistent with the results of Ahuja et al. [8] (Fig. 3B). 4. Discussion Recently, a number of laboratories have reported different translocations that involved the NUP98 gene located on 11p15.5 in various hematologic malignancies. At least eight different fusion partners of the NUP98 gene have been cloned such as PMX1 in t(1;11)(q23;p15.5) seen in patients with t-MDS/AMoL [10]; HOXD13 in t(2;11)(q31;p15.5) in patients with de novo AMoL and t-MDS/AMoL [11]; RAP1GDS1 in t(4;11)(q21;p15.5) in patients with t-acute lymphocytic leukemia [12]; NSD1 in t(5;11)(q35;p15.5) in patients with AMoL [13]; HOXA9 in t(7;11)(p15;p15.5) in patients with AMoL, MDS, tMDS/AMoL, and chronic myelogenous leukemia [2,3]; LEDGF in t(9;11)(p22;p15.5) in patients with AMoL [14]; and DDX10 in inv(11)(p15q22) in patients with AMoL and t-MDS/AMoL [15]. The first case with t(11;20)(p15;q11) was reported in a patient with polycythemia vera (PV) in 1972 [4]. Mitelman et al. [5] and Betts et al. [6] reported three AMoL-M2 pa-
155
tients with this translocation. Then Ahuja et al. [8] demonstrated that TOP1 on 20q11 was the partner of NUP98 gene in this translocation in two t-MDS patients. Recently, Kakazu et al. [7] reported an AMoL-M5b patient with t(11;20) (p15;q11.2). Fluorescence in situ hybridization (FISH) analysis using a probe for the NUP98 gene showed that the NUP98 gene was involved in this patient. But they could not investigate the genomic rearrangement of the TOP1 or detect NUP98-TOP1 fusion transcript because high molecular weight DNA or RNA could not be obtained [7]. Here we presented another AMoL-M5b patient with a t(11;20)(p15;q11). Conventional cytogenetic analysis and chromosome painting using WCP 11 and 20 demonstrated the existence of this translocation. Moreover, NUP98-TOP1 fusion transcript was detected by RT-PCR. In view of the fact that t(11;20) has been found in various myelocytic disorders including PV, MDS, and AMoL, whereas lymphocytic proliferative diseases with t(11;20) have not been reported thus far, we consider that this translocation is associated with myelocytic disorder rather than lymphocytic proliferative diseases. As the chromosome segment involved in this translocation is small, it may be difficult to detect by cytogenetics alone. RT-PCR and/or FISH may be more reliable methods for the detection of this abnormality. The patients with t(11;20)(p15;q11) may be associated with a poor prognosis because two AMoL-M2 patients described by Mitelman et al. [5] showed partial or no response to induction
Fig. 3. (Above) The results of RT-PCR showing a 420-bp band corresponding to NUP98-TOP1 fusion product in the present case (lane 1: a healthy person as negative control; lane 2: present case; and M: pUC19 DNA/MspI (HpaI) marker (MBI Fermentas). (Below) The sequences around the breakpoints of the NUP98 and TOP1 genes and the NUP98-TOP1 sequence. Boldface represents the sequence derived from the TOP1 gene. NUP98: 5-ATGTCAGACCCTAAGAAGAAGGAAGAGAGATTGAAACCAAC AAATCCAGCAGCC-3 MSDPLLLEERLKPTNPAA
Fig. 2. Chromosome painting analysis demonstrating a red fluorescent signal on the terminal portion of the short arm of chromosome 11 with a green fluorescent signal, while no green fluorescent signal was seen on the terminal of one chromosome 20 with shorter red fluorescent signal than its homologue.
NUP98-TOP1: 5-ATGTCAGACCCTAAGAAGAAGGAAGAGGATGGTAAATTGAA AAAACCCAAGAAT-3 MSDPLLLEEDGKLKKPKN TOP1: 5-AGAAAAAGAAAACTAGAAGAAGAAGAGGATGGTAAATTGAA AAAACCCAAGAAT-3 RKRKLEEEEDGKLKKPKN
156
S. Chen et al. / Cancer Genetics and Cytogenetics 140 (2003) 153–156
chemotherapy, and in an AML-M5b patient reported by Kakazu et al. [7], the leukemia relapsed in one year. As for our patient, he was treated with one course of DA regimen and died of intracranial hemorrhage on day 12 after chemotherapy. Thus, we cannot evaluate the effectiveness of chemotherapy. The number of cases with t(11;20)p15;q11) reported so far is too small to draw firm conclusions about the prognosis of the diseases with this translocation. Thus, it is necessary to accumulate more data on patients with t(11;20)(p15;q11).
[7]
[8]
[9] [10]
References [1] Radu A, Moore MS, Blobel G. The peptide repeat domain of nucleoporin NUP98 functions as a docking site in transport across the nuclear pore complex. Cell 1995;81:215–22. [2] Nakamura T, Largaespada DA, Lee MP, Johnson LA, Ohyashiki K, Toyama K, Chen SJ, Willman CL, Chen IM, Feinberg AP, Jenkins NA, Copeland NG, Shaughnessy JD. Fusion of nucleoporin gene NUP98 to HOXA9 by the chromosome translocation t(7;11)(p15; p15) in human myeloid leukaemia. Nat Genet 1996;12:154–8. [3] Borrow J, Shearman AM, Stanton VP, Becher R, Collins T, Williams AJ, Dube I, Katz F, Kwong YL, Morris C, Ohyashiki K, Toyama K, Rowley J, Housman DE. The t(7;11)(p15;p15) translocation in acute myeloid leukaemia fuses the gene for nucleoporin NUP98 and class I homeoprotein HOXA9. Nat Genet 1996;12:159–67. [4] Berger R. Translocation t(11;20) et polyglobulic primitive. [abstract] Nouv Presse Med 1972;4:1975. [5] Mitelman F, Prigogina EL, Fleischman EW, Frenkel MA, Garwicz S, Heim S, Ilyinskaya GW, Kristoffersson V, Mandahl N, Volkova, MA. A new-specific chromosomal rearrangement t(11;20)(p15;q11) in myeloblastic leukemia with maturation. Leukemia 1988;2:430–2. [6] Betts DR, Greiner J, Feldges A, Niggli FK. A further case of a t(11;
[11]
[12]
[13]
[14]
[15]
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