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)

Studies on cell-membrane-bound proteins in the human hematopoetic system revealed that the expression of certain peptides is restricted to the differentiation lineage. We applied discontinuous polyacrylamide gel electrophoresis of triton X-114 lysates to identify such proteins for a new diagnostic approach in human leukemia. A polypeptide with an apparent molecular mass range of 24 kd (p24) was found predominantly in cells of chronic granulocytic leukemia (CGL), myeloic type of blast crisis, and normal granulocytes. The data presented here suggest a role of this protein in the biology of malignant cells in chronic granulocytic leukemia throughout the course of the disease.
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PMID:Heterogeneity in protein patterns of CGL blast crisis cells: discrimination between lymphatic and myeloic lineages. 232 63

Thymidine phosphorylase (dThdPase) is an enzyme involved in pyrimidine nucleoside metabolism, but little is known about its physiological functions. We purified dThdPase from human placenta and used it for antibody preparation. The purified material appears as a single band at 55,000 dalton on sodium dodecylsulfate-polyacrylamide gel electrophoresis. We obtained a specific antibody raised in rabbits that detected a single polypeptide with a molecular weight of 55,000 dalton in the post nuclear homogenates of several human tissues, on immunoblotting. Using the same technique, dThdPase was highly expressed in the liver, lung, spleen, lymph nodes and peripheral lymphocytes. Immunohistochemical staining revealed that macrophage-like cells contained a much higher amount of dThdPase than parenchymal cells in the liver and lung. dThdPase was found to be highly expressed in T- and B-cell-type malignant lymphoma cells, but low in lymphoblastic and myeloblastic leukemia cells. We also found that carcinomas in the stomach, colon and ovary contained higher amounts of this enzyme than non-neoplastic regions of the tissues. These data suggest that dThdPase plays a role in proliferation and/or differentiation of leukocytes and in cancer proliferation.
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PMID:Purification and tissue distribution of human thymidine phosphorylase; high expression in lymphocytes, reticulocytes and tumors. 232 55

Nuclear extracts of cultured human cells contain multiple proteins that recognize specific sequence elements within the transcriptional control region of the human retrovirus, human T-cell leukemia virus type I (HTLV-I). Here we report the purification of host expression factor 1T (HEF-1T), a DNA-binding protein from human T-lymphocytes that binds to each of the three 21-base pair repeat enhancer elements in the proviral long terminal repeats of HTLV-I and the related virus, HTLV-II. HEF-1T is composed of two polypeptides of 41 and 59 kDa. We show that HEF-1T is distinct from a second protein, present in non-lymphoid cells, that binds to overlapping sites in and near the 21-base pair repeats. This second protein is composed of a single 47-kDa polypeptide and appears to be identical to the previously described transcription factor AP-2. A third protein, also distinct from HEF-1T, binds within the first repeat. The present results suggest that there may be multiple modes of HTLV-I promoter recognition involving distinct sets of cellular proteins.
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PMID:Interaction of cellular proteins with the human T-cell leukemia virus type I transcriptional control region. Purification of cellular proteins that bind the 21-base pair repeat elements. 233 23

To identify gene products that might be involved in leukemogenesis of adult T-cell leukemia (ATL), we constructed a cDNA library from an ATL tumor cell line named IKD. By differential plaque hybridization using [32P]cDNAs of poly(A)+ RNA from IKD cells and a human T-lymphotropic virus type I-infected T-cell line (C91/PL) as probes and RNA blot analysis, we obtained a single cDNA clone of a gene that is highly expressed in IKD cells. Expression of this gene was also detected in fresh peripheral blood mononuclear cells of several ATL patients but not in those of healthy donors. Sequence analysis showed that the cDNA was that of a previously undescribed gene. On structural analysis of the cDNA (1,897 base pairs), a short open reading frame encoding a polypeptide of 54 amino acid residues was found. Exposure of human peripheral blood mononuclear cells, a T-cell lymphoma cell line (Jurkat), and quiescent human embryonic lung cells to phorbol-12-myristate-13-acetate resulted in rapid, transient expression of 2.0-kilobase mRNA of this gene. This induction of the gene was not inhibited by an inhibitor of protein synthesis, cycloheximide. From these findings, we suggest that this gene, named APR, is a member of the cellular immediate-early-response genes.
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PMID:Molecular cloning and characterization of a cDNA for a novel phorbol-12-myristate-13-acetate-responsive gene that is highly expressed in an adult T-cell leukemia cell line. 239 25

A series of monoclonal antibodies (mAb) were raised against nonlymphoid leukemic cell lines. Three of them have been characterized in detail. mAb H8 (IgG2), mAB U2 (IgG1), and mAb ML143 (IgM) were established with HEL, an erythroleukemia cell line, U937, a monocytoid (histiocytic) line, and ML-1, a myeloid cell line as immunogen, respectively. A 65 to 75 KD polypeptide was precipitated from monocytes by mAb H8, a 160 KD protein from monocytes by mAb U2, and two broad bands in the regions of 150 and 195 KD from granulocytes by mAb ML143. All three mAb stained peripheral blood monocytes and granulocytes, but not lymphocytes, platelets, and erythrocytes. The mAb reacted with immature myeloid cells in bone marrow, ranging from myeloblasts to mature myelomonocytic cells. They also were reactive with various nonlymphoid cell lines and leukemia of myelomonocytic origin. They did not react with B cell lines and B cell CLL cells. By complement-mediated cytolysis and/or an immune rosette method, antigens H8 and U2 were found to be expressed on the vast majority of CFU-GM (14 days) progenitors but not on BFU-E. Antigen ML143 was not expressed by either progenitor. Furthermore, ML143 antigen was found on T leukemia cell lines, a subpopulation of mitogen-activated T cells, and certain non-T/non-B ALL cells. This reactivity was not found with mAb H8 and U2. The relationship between these mAb and those reported are discussed. The possibility of using these mAb to obtain a markedly enriched CFU-GM progenitor population is also raised.
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PMID:Monoclonal antibodies against human myelomonocytic cells: detection of certain lineage-specific antigens on CFU-GM progenitor cells. 240 54

Transcription of the c-fos gene is transiently activated to generate large amounts of unstable c-fos RNA when quiescent fibroblasts are stimulated by polypeptide mitogens or whole serum. A cloned human c-fos gene (c-fosH) transfected into mouse fibroblasts is regulated in a similar manner. An element essential for transcription activation is located between nucleotides -332 and -276 relative to the mRNA cap site. This element has properties similar to those of previously characterized transcription enhancer elements. However, replacement of the 5' activating element by enhancers from SV40 or Moloney murine leukemia virus does not allow regulated c-fosH expression. The study of fusion genes showed that in addition to the 5' activating element, transient accumulation of c-fosH RNA following serum stimulation requires sequences at the 3' end of the c-fosH gene.
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PMID:Transient accumulation of c-fos RNA following serum stimulation requires a conserved 5' element and c-fos 3' sequences. 241 12

Vaccines prepared from Friend leukaemia virus envelope and core polypeptides were compared for their efficiency in preventing erythroleukaemia in mice. High doses (100 micrograms) of gp85, the micellar complex of the envelope polypeptides gp70 and p15E, completely protected STU mice. The same dose of purified gp70 still protected about 80% of the animals, while p15E did not affect the cumulative mortality. The internal viral polypeptide p30 was ineffective. Serological examination indicated that immunity against death from leukaemia was mediated by specific antibodies. These leukaemia-preventing antibodies were predominantly induced by immunization with the gp70 env gene product, since p15E showed only minor protection. Glycoprotein gp70, however, was more effective when given as the gp85 micellar complex. An even more potent vaccine was obtained when gp70 was coupled to keyhole limpet haemocyanin (KLH) by glutaraldehyde. Ten micrograms gp70 coupled to KLH was enough to save more than 90% of Friend leukaemia virus-infected mice from erythroleukaemia. KLH may also be a suitable experimental carrier for subunits of gp70 or synthetic oligopeptides for viral vaccines.
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PMID:Immunoprevention of Friend leukaemia virus-induced erythroleukaemia by vaccination with aggregated gp70. 242 46

The amino acid sequence of the vitronectin receptor alpha subunit deduced from cDNA is presented. The sequence defines a 1047-amino-acid polypeptide precursor with a putative signal sequence, a large extracellular domain with several sites homologous to calcium binding sites in other proteins, a transmembrane domain, and a 32-amino-acid cytoplasmic domain. The 7-kilobase vitronectin receptor alpha subunit mRNA was found to be expressed in all cell lines examined, including endothelial cells, K562 and HEL leukemia cells, and osteosarcoma cells. In the two leukemia cell lines, the expression of the vitronectin receptor mRNA, as well as that of the fibronectin receptor, was enhanced in the presence of phorbol ester, a treatment known to increase the adhesiveness of these cells. The HEL cells were the only ones among the cell lines tested that also contained the mRNA of the platelet adhesion receptor alpha subunit, glycoprotein IIb. The expression of glycoprotein IIb was slightly enhanced by treatment of the cells with phorbol ester. These results complete the partial cDNA sequence of the vitronectin receptor alpha subunit published previously (Suzuki, S., Argraves, W. S., Pytela, R., Arai, H., Krusius, T., Pierschbacher, M. D., and Ruoslahti, E. (1986) Proc. Natl. Acad. Sci. U.S.A., 83, 8614-8618), confirm that the vitronectin receptor, and not IIb, is expressed in endothelial cells, and show that changes in the level of its expression correlate with changes in cell adhesiveness.
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PMID:Amino acid sequence of the vitronectin receptor alpha subunit and comparative expression of adhesion receptor mRNAs. 244

Retroviral reverse transcriptase possesses DNA polymerase and ribonuclease H (RNase H) activity within a single polypeptide. Chemical or proteolytic treatment of reverse transcriptase has been used in the past to produce enzyme that is missing DNA polymerase activity and retains RNase H activity. It has not been possible to obtain reverse transcriptase that lacks RNase H but retains DNA polymerase activity. We have constructed a novel deletion derivative of the cloned Moloney murine leukemia virus (M-MLV) reverse transcriptase gene, expressed the gene in E. coli, and purified the protein to near homogeneity. The purified enzyme has a fully active DNA polymerase, but has no detectable RNase H activity. These results are consistent with, but do not prove, the conclusion that the DNA polymerase and RNase H activities of M-MLV reverse transcriptase reside within separate structural domains.
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PMID:Isolation of cloned Moloney murine leukemia virus reverse transcriptase lacking ribonuclease H activity. 244 47

ICO-1 Mab were obtained following BALB/c mouse immunization with 24-week human fetal thymocytes. Cloning for two times by the method of limited dilutions led to a hybridoma with a stable production of G3 isotype Mab. ICO-1 Mab have immunoprecipitated an antigen consisting of two polypeptide chains with molecular weight 29 and 34 kDal. The antigen expression was enhanced following PHA or alloantigen activation of blood mononuclear cells. ICO-1 Mab inhibited the alloantigenic response of blood mononuclear cells. Mab detected 29% of antigen-positive cells in the peripheral blood of healthy adults. When the reaction of ICO-1 Mab was compared with that of Mab against monomorphic Ia-like antigens OKLa, anti-Ia-BRL, BMA-021 and HLA-Dr on blood cells from healthy donors and patients with leukemia proved to be identical.
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PMID:[Standardization of ICO-1 monoclonal antibodies against monomorphic Ia-like (Dr) antigens]. 244 25


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