Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human trithorax-like gene 1 (Htrx1 gene) is disrupted in 11q23 translocations that are associated with acute leukemias. Sequencing of a partial human cDNA revealed an open reading frame encoding 1012 amino acids with extensive homology to the Drosophila trithorax protein, particularly in the zinc finger-like domains. Htrx1 gene appears to be unique in the human genome and has been conserved during evolution. Use of the human cDNA as a probe demonstrates that this gene is interrupted in both infant and adult acute myeloid (AML) and lymphoid (ALL) leukemia patients with 11q23 translocations. The structure of the Htrx1 gene around the breakpoints shows that this part of the human gene is interrupted by nine introns. As a result of the rearrangement, zinc finger domains are translocated in both ALL and AML patients. Expression studies reveal that the Htrx1 gene differentially expresses three transcripts within the normal lymphocyte cell lineage.
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PMID:Structure and expression of the human trithorax-like gene 1 involved in acute leukemias. 850 28

The tissue-specific Wilms' tumor gene WT1 is expressed in a range of acute leukemias and hematopoietic cell lines. Using single-strand conformational polymorphism analysis, we have found mutations in the WT1 gene in 4 of 36 acute leukemias. WT1 mutations are found in 15% of cases of acute myeloid leukemia, in which they are associated with a poor response to chemotherapy. The mutations comprise small insertions in exons 1 and 7 and a nonsense mutation in exon 9. All are predicted to produce a truncated WT1 protein with absence or disruption of the zinc finger region. These are the first mutations in the WT1 gene to be described in sporadic leukemia.
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PMID:Mutations in the Wilms' tumor gene WT1 in leukemias. 863 Mar 76

The retinoblastoma interacting zinc finger gene RIZ is a member of the recently discovered PR domain family that includes the MDS1-EVI1 breakpoint gene involved in human leukemia. To help understand the role of RIZ in human diseases, we have determined the cytogenetic and physical localizations of the RIZ gene. Using fluorescence in situ hybridization, we determined that RIZ maps to 1p36. On the physical map, RIZ is adjacent to the polymorphic marker D1S228. We suggest that the RIZ gene may be a candidate target of 1p36 alterations that commonly occur in neuroendocrine, breast, liver, colon, and lymphoid tumors.
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PMID:Physical mapping of the retinoblastoma interacting zinc finger gene RIZ to D1S228 on chromosome 1p36. 866 Oct 32

Nucleocapsid protein NCp10 of murine leukemia virus (MuLV) is encoded by the 3' domain of gag and contains a zinc finger of the form Cys-X2-Cys-X4-His-X4-Cys flanked by basic amino acids. In the course of virus assembly, NCp10 is necessary for core formation, and the zinc finger flanked by the basic residues is required for the packaging of the genomic RNA dimer. In vitro, NCp10 exhibits strong nucleic acid binding and annealing activities that appear to be critical for virus infectivity since NCp10 promotes dimerization of the viral RNA containing the E/DLS packaging-dimerization signal and annealing of replication primer tRNA(Pro) to the initiation site of reverse transcription (PBS). Recent in vitro studies have suggested that NCp10 may also play a role in proviral DNA synthesis. To investigate the function of NCp10 in proviral DNA synthesis in vivo, we developed a simple and convenient genetic packaging system consisting of two DNA constructs expressing the packaging components gag-pol and env of Friend MuLV and a Moloney MuLV-based lacZ vector with either the MuLV E+ or a rat VL30 E packaging signal. This system allowed us to examine the consequences of a set of mutations in NCp10 on a single round of recombinant virus replication. Most mutations in the N- or C-terminal domain of NCp10 do not significantly alter infectivity, while those in the zinc finger drastically impair infectivity. Analysis of the viral RNA content in virions showed that all mutations in the zinc finger decrease but do not abolish packaging of the recombinant genome. Interestingly enough, mutation of Y-28 to S (mutation Y28S) in the zinc finger results in RNA packaging at a level similar to that observed upon deletion of three prolines and three arginines in the C-terminal domain of NCp10 (mutant delta PR3). However, mutant Y28S is noninfectious while mutant delta PR3 is only threefold less infectious than the wild-type virus, which prompted us to examine the role of NCp10 protein in proviral DNA synthesis in vivo using these nucleocapsid mutants. PCR amplification was used to analyze viral DNA synthesized in newly infected cells, and results indicate that the Y28S zinc finger mutation impairs reverse transcription, thus suggesting that the nucleocapsid protein zinc finger plays a key role in proviral DNA synthesis in vivo.
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PMID:The zinc finger of nucleocapsid protein of Friend murine leukemia virus is critical for proviral DNA synthesis in vivo. 870 95

All retroviral nucleocapsid (NC) proteins, except those of spumaretroviruses, contain one or two copies of the conserved sequence motif C-X2-C-X4-H-X4-C. The conserved cysteine and histidine residues coordinate a zinc ion in each such motif. Rice et al. (W. G. Rice, J. G. Supko, L. Malspeis, R. W. Buckheit, Jr., D. Clanton, M. Bu, L. Graham, C. A. Schaeffer, J. A. Turpin, J. Domagala, R. Gogliotti, J. P. Bader, S. M. Halliday, L. Coren, R. C. Sowder II, L. 0. Arthur, and L. E. Henderson, Science 270:1194-1197, 1995) have described a series of compounds which inactivate human immunodeficiency virus type 1 (HIV-1) particles and oxidize the cysteine thiolates in the NC zinc finger. We have characterized the effects of three such compounds on Moloney murine leukemia virus (MuLV). We find that, as with HIV-1, the compounds inactivate cell-free MuLV particles and induce disulfide cross-linking of NC in these particles. The killed MuLV particles were found to be incapable of synthesizing full-length viral DNA upon infection of a new host cell. When MuLV particles are synthesized in the presence of one of these compounds, the normal maturational cleavage of the Gag polyprotein does not occur. The compounds have no effect on the infectivity of human foamy virus, a spumaretrovirus lacking zinc fingers in its NC protein. The resistance of foamy virus supports the hypothesis that the zinc fingers are the targets for inactivation of MuLV and HIV- I by the compounds. The absolute conservation of the zinc finger motif among oncoretroviruses and lentiviruses and the lethality of all known mutations altering the zinc-binding residues suggest that only the normal, wild-type structure can efficiently perform all of its functions. This possibility would make the zinc finger an ideal target for antiretroviral agents.
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PMID:Inactivation of murine leukemia virus by compounds that react with the zinc finger in the viral nucleocapsid protein. 876 2

In an earlier study on minus-strand DNA synthesis catalyzed by murine leukemia virus reverse transcriptase, we described a prominent pause site near the polypurine tract (J. Guo, W. Wu, Z. Y. Yuan, K. Post, R. J. Crouch, and J. G . Levin, Biochemistry 34:5018-5029, 1995). We now report that pausing at this site is due to a stem-loop structure in the RNA template, formed by interaction of a number of bases in the polypurine tract, including the six G's, and a 3' sequence which includes four C's. Addition of human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein to reverse transcriptase reactions reduces pausing by approximately 8- to 10-fold and stimulates synthesis of full-length DNA. Thus, NC functions as an accessory protein during elongation of minus-strand DNA and increases the efficiency of DNA synthesis, in this case, by apparently destabilizing a region of secondary structure in the template. Since NC is associated with genomic RNA in the viral core and is likely to be part of a viral replication complex, these results suggest that NC may also promote efficient DNA synthesis during virus replication. Mutational analysis indicates that the features of HIV-1 NC which are important for reduction of pausing include the basic amino acids flanking the first zinc finger, the zinc fingers, and the cysteine and aromatic amino acids within the fingers. These findings suggest that reverse transcription might be targeted by drugs which inactivate the zinc fingers of HIV-1 NC.
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PMID:Human immunodeficiency virus type 1 nucleocapsid protein reduces reverse transcriptase pausing at a secondary structure near the murine leukemia virus polypurine tract. 879 60

The expression of the human myeloid zinc finger gene (MZF-1) by human bone marrow cells is necessary for granulopoiesis. We have analyzed the structure and function of the MZF-1 gene by diagnostic polymerase chain reaction, genomic cloning, and promoter analysis. Comparison of human promyelocytic HL-60 cell cDNA with isolated MZF-1 genomic clones indicated that the human MZF-1 gene is without introns and spans approximately 3 kb. Restriction enzyme mapping and Southern analysis indicated further that the human MZF-1 gene is a single-copy gene. Primer extension studies identified the major transcription start site as a thymidine residue located 1102 bp upstream of the ATG translation start codon. A putative TATA box sequence (TAAAAA) was found at -66 bp and a CCAAT box at -130 bp relative to the transcription initiation site. In HL-60 cells, MZF-1 mRNA levels are increased by granulopoietic inducers including retinoic acid and GM-CSF. DNA upstream of the transcription start site contains tandem-repeated consensus retinoic acid response elements at -666 through -696 bp and paired putative GM-CSF-responsive sequences centered at -50 and -100 bp. CAT reporter gene constructs containing these DNA regions promoted transcription and conferred transcriptional responsiveness to retinoic acid and GM-CSF when transfected into HL-60 cells. Additional putative regulatory binding sites included conserved MZF-1 zinc finger binding sequences, the importance of which was suggested by the enhanced expression of the endogenous MZF-1 gene following vector-driven expression of MZF-1 constructs in K562 myeloblastic leukemia cells. These findings provide a clearer basis for understanding the role of MZF-1 gene expression in myeloid cell growth and differentiation.
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PMID:Isolation and functional characterization of the human gene encoding the myeloid zinc finger protein MZF-1. 884 78

The human PRDI-BF1 or BLIMP1 gene and its mouse homolog Blimp1 are members of the recently realized PR domain family that includes the retinoblastoma interacting zinc finger gene RIZ and the MDS1-EVI1 leukemia cancer gene. The specific high-level expression of Blimp1 in late B and plasma cells, its induction during B-cell differentiation, and its ability to drive B-cell maturation suggest that this gene may play a role in the differentiation and pathogenesis of B cells. We have now mapped the physical location of BLIMP1 near the marker D6S447 on human chromosome 6q21-q22.1; we have also mapped Blimp1 to mouse Chromosome 10 at 14 cM distal to the Myb locus and to a region homologous to the location of BLIMP1. Deletions of the 6q21-q22 region are common in several human malignancies, particularly in B-cell non-Hodgkin lymphoma (B-NHL). The data led us to suggest that BLIMP1 may be a candidate B-NHL tumor suppressor gene.
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PMID:The B-lymphocyte maturation promoting transcription factor BLIMP1/PRDI-BF1 maps to D6S447 on human chromosome 6q21-q22.1 and the syntenic region of mouse chromosome 10. 892 66

The human MLL (mixed-lineage leukemia or myeloid-lymphoid leukemia) gene belongs to the trithorax gene family of which the Drosophila trithorax (trx) gene is known to regulate homeotic genes through alternative RNA splicing. To test if such a splicing mechanism also operates in MLL, we evaluated mRNA transcripts from a large number of normal and malignant human cells, making use of RT-PCR, PCR cloning, DNA sequencing and Northern blot analysis. Our findings indicate that different cell types transcribe MLL mRNA species lacking exons that generally encode putative regulatory domains such as AT hooks (exon 3), repression domain (exon 6), zinc finger motifs (exon 8) and activation domain (exon 18). Such findings suggest that posttranscriptional regulation by alternative RNA splicing may play an important role in MLL gene expression and provides the rationale for a mechanism by which this gene, with multiple functional domains, could produce discrete protein products that may prove critical in the regulation of human homeobox genes.
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PMID:Alternative RNA splicing of the MLL gene in normal and malignant cells. 892 10

The EVI-1 gene was originally detected as an ectopic viral insertion site and encodes a nuclear zinc finger DNA-binding protein. Previous studies showed restricted EVI-1 RNA or protein expression during ontogeny; in a kidney and an endometrial carcinoma cell line; and in normal murine oocytes and kidney cells. EVI-1 expression was also detected in a subset of acute myeloid leukaemias (AMLs) and myelodysplasia. Because EVI-1 is expressed in the urogenital tract during development, we examined ovarian cancers and normal ovaries for EVI-1 RNA expression using reverse transcription polymerase chain reaction (RT-PCR) and RNAase protection. Chromosome abnormalities were examined using karyotypes and whole chromosome 3 and 3q26 fluorescence in situ hybridisation (FISH). RNA from six primary ovarian tumours, five normal ovaries and 47 tumour cell lines (25 ovarian, seven melanoma, three prostate, seven breast and one each of bladder, endometrial, lung, epidermoid and histiocytic lymphoma) was studied. Five of six primary ovarian tumours, three of five normal ovaries and 22 of 25 ovarian cell lines expressed EVI-1 RNA. A variety of other non-haematological cancers also expressed EVI-1 RNA. Immunostaining of ovarian cancer cell lines revealed nuclear EVI-1 protein. In contrast, normal ovary stained primarily within oocytes and faintly in stroma. Primary ovarian tumours showed nuclear and intense, diffuse cytoplasmic staining. Quantitation of EVI-1 RNA, performed using RNAase protection, showed ovarian carcinoma cells expressed 0 to 40 times the EVI-1 RNA in normal ovary, and 0-6 times the levels in leukaemia cell lines. Southern analyses of ovarian carcinoma cell lines showed no amplification or rearrangements involving EVI-1. In some acute leukaemias, activation of EVI-1 transcription is associated with translocations involving 3q26, the site of the EVI-1 gene. Ovarian carcinoma karyotypes showed one line with quadruplication 3(q24q27), but no other clonal structural rearrangements involving 3q26. However, whole chromsome 3 and 3q26 FISH performed on lines with high EVI-1 expression showed translocations involving chromosome 3q26. EVI-1 is overexpressed in ovarian cancer compared with normal ovaries, suggesting a role for EVI-1 in solid tumour carcinogenesis or progression. Mechanisms underlying EVI-1 overexpression remain unclear, but may include rearrangements involving chromosome 3q26.
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PMID:Expression of the zinc finger gene EVI-1 in ovarian and other cancers. 893 29


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