The translocation (6;9), associated with a specific subtype of acute myeloid leukemia, results in the fusion of two genes, dek and can, and the expression of a chimeric, leukemia-specific dek-can mRNA.

Abstract

The translocation (6;9) is associated with a specific subtype of acute myeloid leukemia (AML). Previously, it was found that breakpoints on chromosome 9 are clustered in one of the introns of a large gene named Cain (can). cDNA probes derived from the 3' part of can detect an aberrant, leukemia-specific 5.5-kb transcript in bone marrow cells from t(6;9) AML patients. cDNA cloning of this mRNA revealed that it is a fusion of sequences encoded on chromosome 6 and 3' can. A novel gene on chromosome 6 which was named dek was isolated. In dek the t(6;9) breakpoints also occur in one intron. As a result the dek-can fusion gene, present Defined karyotypic aberrations are associated with specific subtypes of leukemia. Detailed molecular characterization of these aberrations may identify genes involved in leukemogenesis and in the precise regulation of proliferation and differentiation in the hematopoietic system. Translocations are the best-studied chromosomal abnormalities. As the result of a translocation, the function or activity of oncogenes located at or near the translocation breakpoint is altered. In myeloid leukemia three translocation breakpoints have been cloned and analyzed at the molecular level.The two best studied, t(9;22) in chronic myeloid leukemia (27, 43) and t(15;17) in acute promyelocytic leukemia (2,8,12), result in the formation of chimeric genes that encode fusion proteins. In chronic myeloid leukemia this is a BCR-ABL protein that has an enhanced tyrosine kinase activity (34, 49) directly responsible for its in vivo tumorigenic potential (14,25). In acute promyelocytic leukemia a PMLRARa fusion protein that represents an altered transcription factor (16, 33) is found.The third translocation is the t(6;9) (p23;q34), found in a specific subtype of acute myeloid leukemia (AML) (1,39,41). This leukemia is characterized by a poor prognosis, affects young adults, and is classified mostly as M2 or M4 and rarely as Ml (according to the French-American-British classification of AML). A region on chromosome 9 situated 360 kb downstream of the c-abl gene was cloned and analyzed. It was found that breakpoints were clustered in a region of 8 kb in five patients, four with t(6;9) AML and one with acute undifferentiated leukemia (AUL) (47). Through cDNA cloning this region could be identified as one of the introns of a large gene (>100 kb) encoding a 7-kb transcript. This intron was named icb-9; the intron containing the breakpoints on chromosome 9 and situated in the middle of * Corresponding author. a gene named Cain (can). The 3' part of can is translocated to the 6p-chromosome, and only 3' can probes detect an additional, leukemia-specific 5.5-kb transcript in bone marrow cells from t(6;9) AML patients. No additional transcripts were detected with 5' can probes. The breakpoint region on chromosome 6p23 was isolated from a genomic XEMBL3 library constructed of bone marrow DNA from one of the t(6;9) patients. An area of 40 kb of chromosome 6 DNA was cloned in overlapping phages. Southern blot analysis sh...

Nup214-Nup88 Nucleoporin Subcomplex Is Required for CRM1-mediated 60 S Preribosomal Nuclear Export

“…To create Nup214-FRB, the FRB domain lacking the HA1 tag from the plasmid pC 4 -R H E (regulated heterodimerization kit, Argent) was PCR-amplified and cloned in-frame into the parental construct using AgeI and SacII sites. To create pcDNA3 HA-Nup214-(585-832), HA-Nup214-(804 -1058), and HA-Nup214-(585-1058), Nup214 regions were PCR-amplified on pBluescriptKS(Ϫ)CAN (47) and cloned into pcDNA3-HA (48). FKBP lacking the HA1 tag and SV40 NLS was PCR-amplified from the plasmid pC 4 EN-F1E (regulated heterodimerization kit, Argent) to clone into pRev(1.4)-GFP (49) using BamHI and AgeI sites and into GST-NLS-GFP from plasmid pEW103 (kind gift of Erik Wiemer, Erasmus University, Rotterdam, The Netherlands) using BsrGI and SacII sites.…”

DAP-kinase loss of expression in various carcinoma and B-cell lymphoma cell lines: possible implications for role as tumor suppressor gene

“…DAPkinase gene was mapped to chromosome 9q34.1 (Feinstein et al, 1995a), a locus that is frequently rearranged in human malignancies. Examples of 9q34.1 aberrations are found in various leukemias (Ellisen et al, 1991;de Klein et al, 1982;von Lindern et al, 1992) and loss of heterozygosity (LOH) at 9q34 is observed in the majority of bladder carcinomas (Knowles and Currie, 1993;Knowles et al, 1994;Tsai et al, 1990). In light of these data it became of interest to follow the pattern of DAP-kinase expression in cell lines established from various types of carcinomas and leukemias.…”

Fusion of NUP214 to ABL1 on amplified episomes in T-cell acute lymphoblastic leukemia

“…Molecular analyses delineated the amplicon as a 500-kb region from chromosome band 9q34, containing the oncogenes ABL1 and NUP214 (refs. 5,6). We identified a previously undescribed mechanism for activation of tyrosine kinases in cancer: the formation of episomes resulting in a fusion between NUP214 and ABL1.…”

“…NUP214 is widely expressed and is involved in the pathogenesis of acute myeloid leukemia associated with the t(6;9)(p23;q34) DEK-NUP214 fusion 6 . In the DEK-NUP214 fusion protein, however, the C-terminal region of NUP214 (encoded by exons 18-36) is present, whereas the predicted NUP214-ABL1 fusions retain the N-terminal region of NUP214, which includes the predicted coiled-coil domains that may serve as oligomerization motifs (Fig.…”