UMLS:C0023418 - FACTA Search

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Query: UMLS:C0023418 (leukemia)
93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retroviruses have been isolated from the tissues of human leukemia patients. Previous studies have shown that these isolates share some antigenic determinants with the family of viruses isolated from the woolly monkey and gibbon ape and that they exhibit partial nuclei acid homology with this same group of viruses. We have compared the RNAs of the viruses by two-dimensional polyacrylamide gel electrophoresis of the large RNase T1-resistant oligonucleotides. The degree of sequence identity between the RNAs was determined by the similarity of their RNase T1-resistant oligonucleotide pattern on gels, fingerprints, and in some cases by partial sequence analysis of individual oligonucleotides. This technique permits us to determine the degree of sequence identity among related RNA species. From our studies we conclude that viruses isolated from the tissues of two human leukemia patients, A1476 and SKA 21-3, as well as some subcultures of a virus isolated from the leukemic tissues of a third patient, HL23V, are closely related to the wooly monkey virus. However, the fingerprints of other HL23 viral isolates are very similar to that of GaLVSF, a gibbon ape leukemia virus isolated from a lymphosarcoma.
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PMID:Relationship of retroviruses isolated from human leukemia tissues to the woolly monkey-gibbon ape leukemia viruses. 624 70

Canine thymus cells infected with virus (HL-23V) produced by human acute myelogenous leukaemia cells in culture were shown in previous reports to produce transforming and non-transforming type C virus similar or identical to the simian sarcoma virus complex SSV(SSAV) and to induce tumours in marmoset monkeys (Bergholz et al. 1977a). In these earlier studies the appearance of breakthrough foci at low dilutions of antiserum in neutralization tests with high-titred anti-SSV(SSAV) serum suggested the presence of another virus, distinct from SSV-(SSAV). We now report the isolation of this component and, by comparative neutralization analysis, demonstrate that it is most closely related to gibbon ape leukaemia virus (GALV). It is distinguished from SSV(SSAV) by kinetics of neutralization and molecular hybridization experiments. This component was readily cloned both from virus produced by HL-23V chronically-infected canine thymus cells established by Teich et al. (1975) when HL-23V was first isolated and from virus produced by HL-23V-induced marmoset tumour cells in culture. The presence of this component in the original leukaemic cell cultures is discussed.
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PMID:Isolation of a virus closely related to gibbon ape leukaemia virus from cells infected with virus (HL-23V) released by human leukaemic cells. 624 31

The tRNAs that are bound to the genomic RNAs of several murine, feline, and primate retroviruses have been identified. Transfer RNAs were divided into those loosely bound and those tightly bound by stepwise thermal dissociation of the 70 S RNA. They were then identified and semiquantitated by aminoacylation. Proline tRNA is the most tenaciously bound tRNA in several strains of murine leukemia virus, two strains of feline leukemia virus, and the primate viruses simian sarcoma, baboon endogenous, and gibbon ape lymphoma. In the feline xenotropic virus, RD-114, tRNAGly is enriched in the most tightly bound fraction. In Mason-Pfizer monkey virus, as in the murine mammary tumor virus, tRNALys is the tRNA most tenaciously bound to its genomic RNA. Besides the most tightly associated tRNA, one or more different tRNAs are found in relatively large amounts in association with the 70 S RNA. (For convenience, we refer to the largest RNA ccomplex (50-70 S) isolated from any of the retroviruses studies as '70 S' RNA.) These tRNAs can be distinguished from the most tightly bound tRNA by the fact that they can be dissociated at lower temperatures. However, they occur in the same relative abundance as the tightly bound tRNA.
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PMID:Differential association of transfer RNAs with the genomes of murine, feline and primate retroviruses. 624 15

Five gibbon ape leukemia virus substrains (two from gibbons with lymphocytic leukemia and three from gibbons with myelogenous leukemia) were examined for unique genomic sequences specific for each form of leukemia. By using sequential adsorption procedures, the genome from each gibbon ape leukemia virus was fractionated into four sets of distinct nucleotide sequences. Based on their hybridization specificities toward DNAs of leukemic tissues, these sequences were designated as follows: (i) "COM," (ii) "LYM" or "MYE," (iii) "UNI," and (iv) "UND." The COM fraction represented sequences common to all of the viral genomes. The LYM fraction, which was isolated only from gibbon ape leukemia viruses associated with lymphocytic leukemia, represented genomic sequences associated with lymphocytic leukemia since the RNA hybridized at a 4- to 15-fold-higher rate to infected tissue DNA from lymphocytic leukemic gibbons than to infected tissue DNA from myelogenous leukemic gibbons. The MYE fraction, which was isolated only from gibbon ape leukemia viruses associated with myelogenous leukemia, represented genomic sequences associated with myelogenous leukemia since the RNA hybridized at a 5- to 15-fold-higher rate to infected tissue DNA from myelogenous leukemic gibbons than to infected tissue DNA from lymphocytic leukemic gibbons. The UNI fraction contained sequences unique to one virus substrain. The UND fraction contained sequences which varied depending upon the substrains involved in the adsorption procedures. These findings suggest that each gibbon ape leukemia virus examined in this study contains subgenomic sequences that are specifically identifiable only with the form of leukemia from which the virus was isolated.
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PMID:Isolation and identification of lymphocytic and myelogenous leukemia-specific sequences in genomes of gibbon oncornaviruses. 625 80

Fresh human B-lymphoblasts established in culture following exposure of adult peripheral blood leukocytes to type C retroviruses of the simian sarcoma virus/simian sarcoma-associated virus-gibbon ape leukemia virus group were analyzed in detail for the presence of the infecting virus. Viral expression ranged from production of low levels of intact virus in a few cultures to the presence of viral RNA and protein in the absence of detectable of levels of complete virus in the majority of the cultures. In situ molecular hybridization assays using 3H-labeled complementary DNA and indirect immunofluorescence assays using antibody to purified viral protein indicated that the expression of viral RNA and proteins are preferentially expressed in only a fraction of the cells in some cultures. If expression of the infecting viral sequences is necessary for the sustained growth of these cells, then those cells detectably synthesizing viral RNA and proteins may be influencing the growth of the remaining virus-negative cells. The lack of virus production in cultures synthesizing viral RNA and protein indicate that these human B-lymphocytes restrict the life cycle of these viruses at some step(s) after transcription of viral RNA or translation of viral protein.
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PMID:Restricted expression of retrovirus nucleic acids and proteins in primate type C virus (gibbon ape leukemia virus-simian sarcoma virus)-initiated human B-lymphoblast cultures. 626 66

Computer-assisted comparison of the 5'-terminal regions of mammalian type C viruses serves as a useful model of evolutionary divergence of noncoding nucleic acid sequences. It has led to the concept that regions of conserved nucleic acid sequences, the slowly divergent sequences, contain signals of translational, transcriptional, or integrative significance. Interspersed among the conserved regions are rapidly divergent sequences in which base changes, insertions, and deletions are especially prevalent. In the present study, CPC-1, a type C virus isolated from Colobus polykomos, was shown to be related to another Old World type C monkey virus, endogenous stump-tailed monkey virus, MAC-1, by analysis of their 5'-terminal nucleotide sequences. The 5'-terminal regions of CPC-1 and MAC-1 showed a 76% nucleotide correspondence and were of similar lengths, 132 and 127 nucleotides, respectively. Previous strong-stop analyses of other type C viruses have defined two subgroups: (i) Rauscher murine leukemia virus and gibbon ape leukemia virus and (ii) baboon endogenous virus and endogenous cat virus RD114. Based on the present sequence analysis of their 5'-terminal sequences, CPC-1 and MAC-1 formed a third subgroup. Computer-assisted comparison of the 5'-terminal sequences of CPC-1 and MAC-1 to the previously reported sequence of avian spleen necrosis virus (SNV) (Shimotohno et al., Nature [London] 285:550-554, 1980) showed SNV to be a member of that subgroup of mammalian type C viruses. Consistent with the inclusion of SNV in this subgroup of mammalian type C viruses, SNV was distantly related to other mammalian type C viruses. Interestingly, the SNV 5'-terminal sequences showed no significant evolutionary relationship by these criteria to the avian leukemia and sarcoma viruses. CPC-1, MAC-1, and SNV contained conserved regulatory signals in similar positions in their 5'-terminal RNA sequences analogous to those observed in other mammalian type C retroviruses. These sequences included the canonical AAUAAA sequence, a palindrome, a putative ribosome binding site, and an integration site. Some of these highly conserved subsequences were common to 3'- and 5'-terminal noncoding sequences of nonviral eucaryotic mRNA's (Efstratiadis et al., Cell 21:653-668, 1980). Thus, analysis and comparison of 5'-terminal nucleotide sequences have been useful in defining common functional signals and in extending the matrix of relationships among retroviruses.
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PMID:5'-terminal nucleotide noncoding sequences of retroviruses: relatedness of two old world primate type C viruses and avian spleen necrosis virus. 626 13

We have cloned the complete genome of an oncogenic primate retrovirus, the San Francisco isolate of gibbon ape leukemia virus, in a lambda phage vector. DNA sequence analysis and restriction endonuclease mapping of the inserted linear provirus demonstrated 9-base pair inverted repeats at its ends, flanking direct terminal repeats 470 base pairs in length. The (-) strong stop region of this DNA showed surprisingly low sequence homology to that of another gibbon ape leukemia virus isolate from an animal with similar disease. Analysis of the clone also revealed the terminal phosphate configuration of the linear provirus. The recombinant phage is suitable for direct use as a hybridization probe to detect homologous retroviral sequences in human cell lines.
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PMID:Molecular cloning and partial characterization of unintegrated linear DNA from gibbon ape leukemia virus. 627 Jun 62

Extrachromosomal DNA was purified from canine thymus cells acutely infected with different strains of infectious primate type C viruses of the woolly monkey (simian) sarcoma helper virus and gibbon ape leukemia virus group. All DNA preparations contained linear proviral molecules of 9.1 to 9.2 kilobases, at least some of which represent complete infectious proviral DNA. Cells infected with a replication-defective fibroblast-transforming sarcoma virus and its helper, a replication-competent nontransforming helper virus, also contained a 6.6- to 6.7-kilobase DNA. These proviral DNA molecules were digested with different restriction endonucleases, and the resultant fragments were oriented to the viral RNA by a combination of partial digestions, codigestion with more than one endonuclease, digestion of integrated proviral DNA, and hybridization with 3'- and 5'-specific viral probes. The 3'- and 5'-specific probes each hybridized to fragments from both ends of proviral DNA, indicating that, in common with those of other retroviruses, these proviruses contain a large terminal redundancy at both ends, each of which consists of sequences derived from both the 3' and 5' regions of the viral RNA. The proviral sequences are organized 3',5'-unique-3',5'. Four restriction enzymes (KpnI, SmaI, PstI, and SstI) recognized sites within the large terminal redundancies, and these sites were conserved within all the isolates tested. This suggests that both the 3' and 5' ends of the genomic RNA of these viruses are extremely closely related. In contrast, the restriction sites within the unique portion of the provirus were not strongly conserved within this group of viruses, even though they were related along most of their genomes. Whereas the 5' 60 to 70% of the RNA of these viruses was more closely related by liquid hybridization experiments than was the 3' 30 to 40%, restriction sites within this region were not preferentially conserved, suggesting that small sequence differences or point mutations or both exist throughout the entire unique portion of the genome among these viruses.
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PMID:Comparative restriction endonuclease maps of proviral DNA of the primate type C simian sarcoma-associated virus and gibbon ape leukemia virus group. 628 21

Baboon endogenous virus (BaEV) is a type C retrovirus present in multiple proviral copies in the DNA of baboons. Although interspecies antigenic determinants present on reverse transcriptase and gag proteins are shared among all mammalian type C viruses, no nucleic acid homology between BaEV and other type C viruses (except RD-114) has been found in conventional liquid hybridization experiments. In this study, we used restriction fragments of cloned BaEV DNA immobilized on nitrocellulose to test for relatedness with [(32)P]cDNA's of various type C and type D viruses. We detected the following distant relationships previously found only through immunological and protein sequencing techniques: (i) eight type C viral cDNA's (the endogenous virus of rhesus monkeys, feline leukemia virus, simian sarcoma virus, gibbon ape leukemia virus, Rauscher murine leukemia virus, BALB-2, NZB, and RD-114) and two type D viral cDNA's (Mason-Pfizer monkey virus and squirrel monkey retrovirus) were able to hybridize with cloned BaEV DNA; (ii) the eight type C probes hybridized to restriction fragments spanning most of the BaEV genome, but only RD-114 hybridized to fragments within the 1.9 kilobases at the 3' end of the genome; (iii) the two type D probes hybridized primarily to fragments within the 1.9 kilobases at the 3' terminus and weakly or not at all elsewhere; and (iv) [(32)P]cDNA's of several other oncornaviruses (mouse mammary tumor virus, equine infectious anemia virus, bovine leukemia virus, and reticuloendotheliosis virus) exhibited no homology with BaEV DNA. DNA sequence analysis has allowed us to orient the BaEV restriction map with the genetic map at both ends of the genome. Homologies between retroviral cDNA's and BaEV clone restriction fragments could thus be related to specific BaEV genes. Whereas type C cDNA's hybridized to fragments from gag, pol, and the pol-env junction, squirrel monkey retrovirus cDNA hybridized only to a fragment coding for the p15E portion of env. Mason-Pfizer monkey virus cDNA also hybridized within the p15E region, but exhibited homology to the 3' half of gp70 as well. These results are discussed relative to previously reported antigenic relatedness of retroviral proteins. The data suggest that BaEV represents an important link in oncornavirus evolution.
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PMID:DNA sequence relationship of the baboon endogenous virus genome to the genomes of other type C and type D retroviruses. 628 72

Cultured human hematopoietic cells from several normal and leukemic sources, including those cells initiated after exposure to primate type C retroviruses were tested for their capacity to induce tumors in young athymic BALB/c (nu/nu) mice after sc inoculation. An attempt was made to correlate these results with virus expression and chromosome patterns. Progressively growing tumor formation was observed in 5 of 18 normal diploid B-lymphoblast lines from normal peripheral blood and in one of three diploid B-lymphoblast lines from leukemic donors established after infection with primate type C viruses (gibbon ape leukemia virus or simian sarcoma virus). In contrast, none of eight spontaneously transformed B-lymphoblast lines with normal diploid karyotypes formed progressively growing tumors, although one formed a tumor that remained the same size (0.5 cm) for several months. Progressive tumor formation occurred in four of seven previously established cell lines of different cell types that had abnormal karyotypes. Of the normal diploid B-lymphoblast cultures exposed to type C viruses, 12 were tested for the presence of viral RNA and structural proteins (p12, p30, gp70), and this information was correlated with tumorigenicity. Four of the six cultures expressing viral RNA or proteins were tumorigenic, whereas only one of six cultures that did not express virus information was positive. The results of this study suggest that expression of type C viral RNA and proteins by human B-lymphoblasts increases their tumorigenicity in nude mice. It is also apparent that caution must be used in attempts to correlate cell tumorigenicity and chromosome abnormalities in nude mice.
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PMID:Effect of type C viral expression and cellular karyotype on human B-lymphoblast tumorigenicity in nude mice. 628 77

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