A NUP98-HOXD13 fusion gene impairs differentiation of B and T lymphocytes and leads to expansion of thymocytes with partial TCRB gene rearrangement.
Expression of a NUP98-HOXD13 (NHD13) fusion gene leads to myelodysplastic syndrome in mice. In addition to ineffective hematopoiesis, we observed that NHD13 mice were lymphopenic; the lymphopenia was due to a decrease in both T and B lymphocytes. Although the pro-B cell (B220(+)/CD43(+)) populations from the NHD13 and wild-type mice were similar, the NHD13 mice showed decreased pre-B cells (B220(+)/CD43(-)), indicating impaired differentiation at the pro-B to pre-B stage. Thymi from NHD13 mice were smaller and overexpressed Hoxa cluster genes, including Hoxa7, Hoxa9, and Hoxa10. In addition, the NHD13 thymi contained fewer thymocytes, with an increased percentage of CD4(-)/CD8(-) (double-negative (DN)) cells and a decreased percentage of CD4(+)/CD8(+) (double-positive) cells; the DN1/DN2 population was increased and the DN3/DN4 population was decreased, suggesting a partial block at the DN2 to DN3 transition. To determine clonality of the thymocytes, we used degenerate RT-PCR to identify clonal Tcrb gene rearrangements. Five of six NHD13 thymi showed an unusual Tcrb gene rearrangement pattern with common, clonal DJ rearrangements, but distinct V-D junctions, suggesting a marked clonal expansion of thymocytes that had undergone a DJ rearrangement, but not completed a VDJ rearrangement. Taken together, these findings demonstrate that expression of the NHD13 transgene inhibits lymphoid as well as myeloid and erythroid differentiation, results in overexpression of Hoxa cluster genes, and leads to a precursor T cell lymphoblastic leukemia/lymphoma.
Choi
Chul Won
CW
Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20889-5105, USA.
Chung
Yang Jo
YJ
Slape
Christopher
C
Aplan
Peter D
PD
D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D015870:Gene Expression / Q000235:genetics / Q000276:immunology; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D018398:Homeodomain Proteins; C084118:Hoxd13 protein, mouse; D028861:Nuclear Pore Complex Proteins; D015514:Oncogene Proteins, Fusion; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014157:Transcription Factors; C093350:nuclear pore complex protein 98; C088144:HoxA protein