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Sample records for moloney murine leukemia

  1. Moloney murine leukemia virus activates NF-kappa B.

    PubMed Central

    Pak, J; Faller, D V

    1996-01-01

    Nonacutely transforming retroviruses, such as Moloney murine leukemia virus (M-MuLV), differ from transforming viruses in their mechanisms of tumor induction. While the transforming viruses cause tumors by transduction of oncogenes, the leukemia retroviruses, lacking oncogenes, employ other mechanisms, including promoter insertion and enhancer activation. Although these two mechanisms occur in many tumors induced by leukemia viruses, a substantial proportion of such tumors do not show site-specific proviral insertions. Thus, other, unidentified virus-driven mechanisms may participate in tumorigenesis. In these studies, we show that infection of cells by M-MuLV activates expression of Rel family transcription factors. In murine cells chronically infected with M-MuLV, gel shift analyses with kappaB DNA-binding motifs from the murine immunoglobulin kappa light chain enhancer demonstrated induction of at least two distinct kappaB enhancer-binding complexes. Supershifting and immunoblotting analyses defined p50, p52, RelB, and c-Rel subunits as constituents of these virus-induced protein complexes. Transient transfections performed with kappaB-dependent reporter plasmids showed transcriptional activation in M-MuLV-infected cells relative to uninfected cells. Induction of Rel/NF-kappaB transcription factor activity by M-MuLV infection may prove relevant to the mechanism of M-MuLV-induced leukemia. PMID:8648762

  2. Identification of a RNA Polymerase II Initiation Site in the Long Terminal Repeat of Moloney Murine Leukemia Viral DNA

    NASA Astrophysics Data System (ADS)

    Fuhrman, Shella A.; van Beveren, Charles; Verma, Inder M.

    1981-09-01

    We have used a soluble in vitro RNA polymerase II transcription system to define the site of initiation of Moloney murine leukemia viral RNA synthesis. Molecularly cloned integrated and unintegrated Moloney murine leukemia virus DNAs were used as templates. The 5' ends of in vitro transcripts and virion RNA of Moloney murine leukemia virus were compared by nuclease S1 protection experiments. Our results indicate that viral sequences upstream of the in vivo cap site are implicated in the transcription of viral RNA and that the 5' end of an in vitro transcript derived from an integrated Moloney murine leukemia virus clone corresponds to the 5' end of viral genomic RNA.

  3. Hexagonal organization of Moloney murine leukemia virus capsid proteins.

    PubMed

    Mayo, Keith; McDermott, Jason; Barklis, Eric

    2002-06-20

    To help elucidate the mechanisms by which retrovirus structural proteins associate to form virus particles, we have examined membrane-bound assemblies of Moloney murine leukemia virus (M-MuLV) capsid (CA) proteins. Electron microscopy and image reconstruction techniques showed that CA dimers appear to function as organizational subunits of the cage-like, membrane-bound protein arrays. However, new three-dimensional (3D) data also were consistent with hexagonal (p6) assembly models. The p6 3D reconstructions of membrane-bound M-MuLV CA proteins gave unit cells of a = b = 80.3 A, c = 110 A, gamma = 120 degrees, in which six dimer units formed a cage lattice. Neighbor cage hole-to-hole distances were 45 A, while distances between hexagonal cage holes corresponded to unit cell lengths (80.3 A). The hexagonal model predicts two types of cage holes (trimer and hexamer holes), uses symmetric head-to-head dimer building blocks, and permits the introduction of lattice curvature by conversion of hexamer to pentamer units. The M-MuLV CA lattice is similar to those formed in helical tubes by HIV CA in that hexamer units surround cage holes of 25-30 A, but differs in that M-MuLV hexamer units appear to be CA dimers, whereas HIV CA units appear to be monomers. These results suggest that while general assembly principles apply to different retroviruses, clear assembly distinctions exist between these virus types. (c) 2002 Elsevier Science (USA).

  4. Large-scale purification of gp70 from Moloney murine leukemia virus.

    PubMed

    Pyle, S W; Chabot, D J; Miller, T L; Serabyn, S A; Bess, J W; Arthur, L O

    1991-05-01

    The external envelope glycoprotein, gp70, of the Moloney murine leukemia virus was extracted from NIH 3T3 cells utilizing the detergent n-octyl-beta-D-glycopyranoside. The extracted gp70 was sequentially purified utilizing lectin-affinity, anion-exchange, and molecular-exclusion chromatography techniques. Approximately 10 mg of gp70 was purified by this method and shown to be 95% homogeneous, as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The presence of purified gp70 from Moloney murine leukemia virus was confirmed by amino acid analysis, amino-terminal sequencing, and immunoreactivity with a monoclonal antibody raised against gp70. The procedure is rapid, utilizes commercially available media, and can be used to purify large amounts of retroviral envelope glycoprotein from virus.

  5. Relationship Between Moloney Murine Leukemia and Sarcoma Virus RNAs: Purification and Hybridization Map of Complementary DNAs from Defined Regions of Moloney Murine Sarcoma Virus 124

    PubMed Central

    Dina, Dino; Beemon, Karen

    1977-01-01

    Complementary DNAs (cDNA's) specific for various regions of the Moloney murine sarcoma virus (MSV) 124 RNA genome were prepared by cross-hybridization techniques. A cDNA specific for the first 1,000 nucleotides adjacent to the RNA 3′ end (cDNA 3′) was prepared and shown to also be complementary to the 3′-terminal 1,000 nucleotides of a related Moloney murine leukemia virus (MLV) genome. A cDNA complementary to the “MSV-specific” portion of the MSV 124 genome was prepared. This cDNA was shown not to anneal to Moloney MLV RNA and to anneal to a portion of the viral RNA of about 1,500 to 1,800 nucleotides in length, located 1,000 nucleotides from the 3′ end of MSV RNA. A cDNA common to the genome of MSV and MLV was also obtained and shown to anneal to the 5′-terminal two-thirds, as well as to the 3′-terminal 1,000 nucleotides, of the MSV RNA genome. This cDNA also annealed to the RNA from MLV and mainly to the 5′-terminal half of the MLV genome. It is concluded that the 6-kilobase Moloney MSV 124 RNA genome has a sequence arrangement that includes (i) a 3′ portion of about 1,000 nucleotides, which is also present at the 3′ terminus of MLV; (ii) an MSV-specific region, not shared with MLV, which extends between 1,000 and 2,500 nucleotides from the 3′ terminus; and (iii) a second “common” region, again shared with MLV, which extends from 2,500 nucleotides to the 5′ terminus. This second common region appears to be located in the 5′ half of the 10-kilobase MLV genome as well. Experiments in which a large excess of cold MLV cDNA was annealed to 3H-labeled polyadenylic acid-containing fragments of MSV RNA gave results consistent with this arrangement of the MSV genome. PMID:197259

  6. Sequences responsible for erythroid and lymphoid leukemia in the long terminal repeats of Friend-mink cell focus-forming and Moloney murine leukemia viruses.

    PubMed Central

    Ishimoto, A; Takimoto, M; Adachi, A; Kakuyama, M; Kato, S; Kakimi, K; Fukuoka, K; Ogiu, T; Matsuyama, M

    1987-01-01

    Despite the high degree of homology (91%) between the nucleotide sequences of the Friend-mink cell focus-forming (MCF) and the Moloney murine leukemia virus (MuLV) genomic long terminal repeats (LTRs), the pathogenicities determined by the LTR sequences of the two viruses are quite different. Friend-MCF MuLV is an erythroid leukemia virus, and Moloney MuLV is a lymphoid leukemia virus. To map the LTR sequences responsible for the different disease specificities, we constructed nine viruses with LTRs recombinant between the Friend-MCF and Moloney MuLVs. Analysis of the leukemia induced with the recombinant viruses showed that a 195-base-pair nucleotide sequence, including a 75-base-pair nucleotide Moloney enhancer, is responsible for the tissue-specific leukemogenicity of Moloney MuLV. However, not only the enhancer but also its downstream sequences appear to be necessary. The Moloney virus enhancer and its downstream sequence exerted a dominant effect over that of the Friend-MCF virus, but the enhancer sequence alone did not. The results that three of the nine recombinant viruses induced both erythroid and lymphoid leukemias supported the hypothesis that multiple viral genetic determinants control both the ability to cause leukemia and the type of leukemia induced. PMID:3033317

  7. Two base changes restore infectivity to a noninfectious molecular clone of Moloney murine Leukemia virus (pMLV-1)

    SciTech Connect

    Miller, A.D.; Verma, I.M.

    1984-01-01

    The complete nucleotide sequence of a molecular clone of Moloney murine leukemia virus (pMLV-1) has previously been reported. However, pMLV-1 does not generate infectious virus after transfection into cells. The lesion in pMLV-1 has been localized by determining the biological activity of recombinants containing DNA from kilobase pair region which spans the gag-pol junction of pMLV-1 with the corresponding DNA fragment from the infectious clone (pMLV-48) and pMLV-1 reveals two single base pair changes. The mutation in the pol gene does not affect the production of infectious virus but renders them XC negative, whereas the mutation in the gag gene appears to be lethal. The complete nucleotide sequence of an infectious clone of Moloney murine leukemia virus can now be deduced.

  8. Transcriptional Silencing of Moloney Murine Leukemia Virus in Human Embryonic Carcinoma Cells.

    PubMed

    Wang, Gary Z; Goff, Stephen P

    2017-01-01

    Embryonic carcinoma (EC) cells are malignant counterparts of embryonic stem (ES) cells and serve as useful models for investigating cellular differentiation and human embryogenesis. Though the susceptibility of murine EC cells to retroviral infection has been extensively analyzed, few studies of retrovirus infection of human EC cells have been performed. We tested the susceptibility of human EC cells to transduction by retroviral vectors derived from three different retroviral genera. We show that human EC cells efficiently express reporter genes delivered by vectors based on human immunodeficiency virus type 1 (HIV-1) and Mason-Pfizer monkey virus (M-PMV) but not Moloney murine leukemia virus (MLV). In human EC cells, MLV integration occurs normally, but no viral gene expression is observed. The block to MLV expression of MLV genomes is relieved upon cellular differentiation. The lack of gene expression is correlated with transcriptional silencing of the MLV promoter through the deposition of repressive histone marks as well as DNA methylation. Moreover, depletion of SETDB1, a histone methyltransferase, resulted in a loss of transcriptional silencing and upregulation of MLV gene expression. Finally, we provide evidence showing that the lack of MLV gene expression may be attributed in part to the lack of MLV enhancer function in human EC cells.

  9. Structural basis of suppression of host translation termination by Moloney Murine Leukemia Virus

    NASA Astrophysics Data System (ADS)

    Tang, Xuhua; Zhu, Yiping; Baker, Stacey L.; Bowler, Matthew W.; Chen, Benjamin Jieming; Chen, Chen; Hogg, J. Robert; Goff, Stephen P.; Song, Haiwei

    2016-06-01

    Retroviral reverse transcriptase (RT) of Moloney murine leukemia virus (MoMLV) is expressed in the form of a large Gag-Pol precursor protein by suppression of translational termination in which the maximal efficiency of stop codon read-through depends on the interaction between MoMLV RT and peptidyl release factor 1 (eRF1). Here, we report the crystal structure of MoMLV RT in complex with eRF1. The MoMLV RT interacts with the C-terminal domain of eRF1 via its RNase H domain to sterically occlude the binding of peptidyl release factor 3 (eRF3) to eRF1. Promotion of read-through by MoMLV RNase H prevents nonsense-mediated mRNA decay (NMD) of mRNAs. Comparison of our structure with that of HIV RT explains why HIV RT cannot interact with eRF1. Our results provide a mechanistic view of how MoMLV manipulates the host translation termination machinery for the synthesis of its own proteins.

  10. Efficient N-tailing of blunt DNA ends by Moloney murine leukemia virus reverse transcriptase

    PubMed Central

    Ohtsubo, Yoshiyuki; Nagata, Yuji; Tsuda, Masataka

    2017-01-01

    Moloney murine leukemia virus reverse transcriptase (MMLV-RT) is a widely used enzyme for cDNA synthesis. Here we show that MMLV-RT has a strong template-independent polymerase activity using blunt DNA ends as substrate that generates 3′ overhangs of A, C, G, or T. Nucleotides were appended efficiently in the order A > G > T > C, and tail lengths varied from 4 to 5, 2 to 7, 2 to 4, and 2 to 3 for A, C, G, and T, respectively. The activity was so strong that nearly all our test DNA ends were appended with at least one A, C, G, or T. The N-tailing activity of MMLV-RT was enhanced in the presence of Mn2+, and the G-, C-, and T-tailing activities were further enhanced by dCMP, dGMP, and dAMP, respectively. This is the first report of an enzymatic activity that almost thoroughly appends two or more As, or one or more Cs, Gs, or Ts to the 3′ end of double-stranded DNA, which would enable exhaustive analysis of DNA samples. The N-tailing activity of MMLV-RT is potentially useful in many biotechnological applications. PMID:28150748

  11. Efficient N-tailing of blunt DNA ends by Moloney murine leukemia virus reverse transcriptase.

    PubMed

    Ohtsubo, Yoshiyuki; Nagata, Yuji; Tsuda, Masataka

    2017-02-02

    Moloney murine leukemia virus reverse transcriptase (MMLV-RT) is a widely used enzyme for cDNA synthesis. Here we show that MMLV-RT has a strong template-independent polymerase activity using blunt DNA ends as substrate that generates 3' overhangs of A, C, G, or T. Nucleotides were appended efficiently in the order A > G > T > C, and tail lengths varied from 4 to 5, 2 to 7, 2 to 4, and 2 to 3 for A, C, G, and T, respectively. The activity was so strong that nearly all our test DNA ends were appended with at least one A, C, G, or T. The N-tailing activity of MMLV-RT was enhanced in the presence of Mn(2+), and the G-, C-, and T-tailing activities were further enhanced by dCMP, dGMP, and dAMP, respectively. This is the first report of an enzymatic activity that almost thoroughly appends two or more As, or one or more Cs, Gs, or Ts to the 3' end of double-stranded DNA, which would enable exhaustive analysis of DNA samples. The N-tailing activity of MMLV-RT is potentially useful in many biotechnological applications.

  12. Effect of internal genomic sequences of the Moloney murine leukemia virus on replication

    SciTech Connect

    Fomin, I.K.; Lobanova, A.B.; Voitenok, N.N.

    1995-11-01

    Construction and use of retrovirus vectors derived from the Moloney murine leukemia virus (MoMuLV) are described. These vectors, designated minimal vectors, contain the left and right long terminal repeats (LTRs), a binding site for proline tRNA, a polypurine tract (PPT), and a dominant marker for selective introduction of vectors into a packaging cell line, but lack the internal sequences of the virus genome. The experiments showed that the minimal vectors can be replicated and that their titer was approximately 1500-fold lower than that of wild-type vectors. The minimal vectors were shown to contain all the cis-acting sequences necessary for correct reverse transcription. One infectious virion, like wild-type viruses, produced only one provirus. Unlike the avian reticuloendotheliosis virus (REV), {Psi}{sup +} and {Psi}{sup {minus}} genomes of MoMuLV did not compete for virion proteins in the {Psi}2 packaging cell line. When an insert was introduced into a central part of the LTR U5 region, the titer of the minimal vector remained the same, while the titer of the wild-type vector decreased approximately 40-fold. 28 refs., 2 figs., 2 tabs.

  13. Structural basis of suppression of host translation termination by Moloney Murine Leukemia Virus

    PubMed Central

    Tang, Xuhua; Zhu, Yiping; Baker, Stacey L.; Bowler, Matthew W.; Chen, Benjamin Jieming; Chen, Chen; Hogg, J. Robert; Goff, Stephen P.; Song, Haiwei

    2016-01-01

    Retroviral reverse transcriptase (RT) of Moloney murine leukemia virus (MoMLV) is expressed in the form of a large Gag–Pol precursor protein by suppression of translational termination in which the maximal efficiency of stop codon read-through depends on the interaction between MoMLV RT and peptidyl release factor 1 (eRF1). Here, we report the crystal structure of MoMLV RT in complex with eRF1. The MoMLV RT interacts with the C-terminal domain of eRF1 via its RNase H domain to sterically occlude the binding of peptidyl release factor 3 (eRF3) to eRF1. Promotion of read-through by MoMLV RNase H prevents nonsense-mediated mRNA decay (NMD) of mRNAs. Comparison of our structure with that of HIV RT explains why HIV RT cannot interact with eRF1. Our results provide a mechanistic view of how MoMLV manipulates the host translation termination machinery for the synthesis of its own proteins. PMID:27329342

  14. Identification of a subdomain in the Moloney murine leukemia virus envelope protein involved in receptor binding.

    PubMed Central

    MacKrell, A J; Soong, N W; Curtis, C M; Anderson, W F

    1996-01-01

    We have mutated amino acids within the receptor-binding domain of Moloney murine leukemia virus envelope in order to identify residues involved in receptor binding. Analysis of mutations in the region of amino acids 81 to 88 indicates that this region is important for specific envelope-receptor interactions. None of the aspartate 84 (D-84) mutants studied bind measurably, although they are efficiently incorporated into particles. D-84 mutants have titers that correspond to the severity of the substitution. This observation suggests that D-84 may provide a direct receptor contact. Mutations in the other charged amino acids in this domain (R-83, E-86, and E-87) yield titers similar to those of wild-type envelope, but the affinity of the mutant envelope in the binding assay is decreased by nonconservative substitutions in parallel to the severity of the change. These other amino acids may either provide secondary receptor contacts or assist in maintaining a structure in the domain that favors efficient binding. We also studied other regions of high hydrophilicity. Our initial characterization indicates that amino acids 106 to 111 and 170 to 188 do not play a major role in receptor binding. Measurements of relative binding affinity and titer indicate that most mutations in the region of amino acids 120 to 131 did not significantly affect receptor binding. However, SU encoded by mutants H123V, R124L, and C131A as well as C81A could not be detected in particles and therefore did not bind measurably. Therefore, the region encompassed by amino acids 81 to 88 appears to be directly involved in receptor binding. PMID:8627699

  15. Localization of actin in Moloney murine leukemia virus by immunoelectron microscopy.

    PubMed

    Nermut, M V; Wallengren, K; Pager, J

    1999-07-20

    Immunoelectron microscopy was used to detect actin in wild-type (wt) Moloney murine leukemia virus (MoMuLV) and in virus-like particles (VLP) produced by recombinant Semliki Forest virus expressing only the MoMuLV gag polyprotein. Gold immunolabeling revealed the presence of actin on the surface of delipidized VLP and delipidized wt virus particles. Statistical evaluation of the number of colloidal gold particles per VLP revealed a large range of values and a prevalence of VLP with small numbers of gold particles. Labeling for actin was lost after prolonged treatment of VLP with 1% Nonidet-P40, high-pH buffer, or gelsolin. Gold immunolabeling with antibodies to gag proteins p15 (MA) and p12 and p30 (CA) was abundant and was not affected by treatment of VLP or wt virus with 1% Nonidet or gelsolin. VLP treated with a mixture of detergent and aldehyde fixatives showed more uniform and consistent labeling for actin than without fixatives. Negative staining or heavy metal shadowing revealed a globular surface of delipidized VLP. Stereomicrographs of gold-immunolabeled VLP showed that p15gag and p12gag were associated with the globular projections. Delipidized VLP were also well labeled with antibody to p30gag, which indicated that the gag shell permitted access of antibodies to p30gag and was therefore not a closely packed structure. Labeling for actin-binding proteins moesin and ezrin was negative in both the wt virus and the VLP. The absence of Gaussian distribution of actin in the sample of VLP suggests that actin is not a structural protein and its presence in MuLV virus particles may be fortuitous. This, however, does not rule out any possible role of actin in transport, assembly, budding, or release of virus particles, events which take place in the cytoplasm or at the plasma membrane. The site of actin in VLP is discussed in relation to the present knowledge of the molecular organization of the MuLV gag shell.

  16. Six distinct nuclear factors interact with the 75-base-pair repeat of the Moloney murine leukemia virus enhancer.

    PubMed Central

    Speck, N A; Baltimore, D

    1987-01-01

    Binding sites for six distinct nuclear factors on the 75-base-pair repeat of the Moloney murine leukemia virus enhancer have been identified by an electrophoretic mobility shift assay combined with methylation interference. Three of these factors, found in WEHI 231 nuclear extracts, which we have named LVa, LVb, and LVc (for leukemia virus factors a, b, and c) have not been previously identified. Nuclear factors that bind to the conserved simian virus 40 corelike motif, the NF-1 motif, and the glucocorticoid response element were also detected. Testing of multiple cell lines showed that most factors appeared ubiquitous, except that the NF-1 binding factor was found neither in nuclear extracts from MEL cells nor in the embryonal carcinoma cell lines PCC4 and F9, and core-binding factor was relatively depleted from MEL and F9 nuclear extracts. Images PMID:3561410

  17. Determinants of Moloney murine leukemia virus Gag-Pol and genomic RNA proportions.

    PubMed

    Johnson, Silas F; Collins, John T; D'Souza, Victoria M; Telesnitsky, Alice

    2014-07-01

    The Moloney murine leukemia virus (MoMLV) ribonucleoprotein complex is composed of an approximately 20:1 mixture of Gag and Gag-Pol polyproteins plus a single genomic RNA (gRNA) dimer. The mechanisms that regulate these proportions are unknown. Here, we examined whether virion proportions of Gag, Gag-Pol, and gRNA were determined by sampling (that is, if they reflected expression ratios or intracellular concentrations) or more specific recruitment. To this end, MoMLV Gag, Gag-Pol, and gRNA were expressed separately or together in various ratios. Varying the expression ratios of Gag and Gag-Pol revealed that Gag-Pol incorporation was stochastic and that the conserved 20:1 Gag/Gag-Pol ratio coincided with maximal particle production. When skewed expression ratios resulted in excess Gag-Pol, the released virions maintained the intracellular Gag/Gag-Pol ratios and the infectivity per virion was largely maintained, but virion production decreased sharply with high levels of Gag-Pol. The determinants of gRNA proportions were addressed by manipulating the amounts and contexts of functional nucleocapsid (NC) and the ratios of Gag to gRNA. The results showed that the NC domain of either Gag or Gag-Pol could provide gRNA packaging functions equally well. Unlike Gag-Pol, gRNA incorporation was saturable. An upper limit of gRNA incorporation was observed, and particle production was not disrupted by excess gRNA expression. These results indicate that the determinants of Gag/Gag-Pol proportions differ from those for Gag/gRNA. On the basis of the assumption that MoMLV evolved to produce virion components in optimal proportions, these data provide a means of estimating the proportion of unspliced MoMLV RNA that serves as genomic RNA. Viruses assemble their progeny from within the cells that they parasitize, where they must sort through a rich milieu of host proteins and nucleic acids to gather together their own building blocks, which are also proteins and nucleic acids. The

  18. Nuclease S1-sensitive sites on superhelical DNA molecules carrying the LTR region of Moloney murine leukemia virus.

    PubMed

    Kimura, T; Takeya, T

    1987-04-29

    The long terminal repeat (LTR) from proviral DNA of Moloney murine leukemia virus (Mo-MLV) was cloned on a derivative of pBR322, and after introducing superhelical torsions into the resulting recombinant, the sites of conformational transition were investigated by the nuclease S1-digestion method. With an increase in the negative linking differences, fourteen dominant cutting sites were identified, of which two were mapped inside the LTR and one at the 3' end of the LTR. By searching the sequence data, all these sites were localized in the regions having either palindromic sequences or AT-rich sequences. Free energy calculation for the local secondary structure on one strand indicated that nuclease S1 attacked the palindromic sequence regions which could form relatively stable hairpin structures. Under the conditions used, no correlation was found between the S1-sensitive sites and the potential Z-DNA-forming regions, including those within the enhancer sequence.

  19. Four Moloney murine leukemia virus-infected rat cell clones producing replication-defective particles: protein and nucleic acid analyses.

    PubMed Central

    Yoshimura, F K; Yamamura, J M

    1981-01-01

    Four cloned rat cell lines (NX-1 to -4) infected with Moloney murine leukemia virus and defective in virus replication were found to be all different by viral protein and nucleic acid analyses. All four clones produced noninfectious particles and, except for NX-2, at about the same level as wild type. Compared with wild-type virions these defective particles contained larger amounts of gag precursor proteins and very little or no p30 or p15. Analysis of intracellular precursor proteins revealed that NX-2 to -4 synthesized normal Pr65gag, whereas NX-1 produced a slightly smaller precursor. Both NX-1 and NX-4 synthesized an intracellular polyprotein with a size similar to that of wild-type Pr180 gag-pol. Restriction endonuclease analysis of NX-1 to -4 cellular DNA showed that each clone contained a single integrated provirus which possessed large terminal repeat sequences at both the 5' and 3' ends. The proviruses of NX-1 to -3 appeared normal by restriction endonuclease analysis, but NX-4 provirus had a deletion of 1,700 base pairs comprising part of the polymerase region. The noninfectious particles produced by all four clones packaged Moloney viral RNAs and rat RNAs of two different sizes. Images PMID:6165841

  20. Introduction of a cis-Acting Mutation in the Capsid-Coding Gene of Moloney Murine Leukemia Virus Extends Its Leukemogenic Properties

    PubMed Central

    Audit, Muriel; Déjardin, Jérôme; Hohl, Barbara; Sidobre, Christine; Hope, Thomas J.; Mougel, Marylène; Sitbon, Marc

    1999-01-01

    Inoculation of newborn mice with the retrovirus Moloney murine leukemia virus (MuLV) results in the exclusive development of T lymphomas with gross thymic enlargement. The T-cell leukemogenic property of Moloney MuLV has been mapped to the U3 enhancer region of the viral promoter. However, we now describe a mutant Moloney MuLV which can induce the rapid development of a uniquely broad panel of leukemic cell types. This mutant Moloney MuLV with synonymous differences (MSD1) was obtained by introduction of nucleotide substitutions at positions 1598, 1599, and 1601 in the capsid gene which maintained the wild-type (WT) coding potential. Leukemias were observed in all MSD1-inoculated animals after a latency period that was shorter than or similar to that of WT Moloney MuLV. Importantly, though, only 56% of MSD1-induced leukemias demonstrated the characteristic thymoma phenotype observed in all WT Moloney MuLV leukemias. The remainder of MSD1-inoculated animals presented either with bona fide clonal erythroid or myelomonocytic leukemias or, alternatively, with other severe erythroid and unidentified disorders. Amplification and sequencing of U3 and capsid-coding regions showed that the inoculated parental MSD1 sequences were conserved in the leukemic spleens. This is the first report of a replication-competent MuLV lacking oncogenes which can rapidly lead to the development of such a broad range of leukemic cell types. Moreover, the ability of MSD1 to transform erythroid and myelomonocytic lineages is not due to changes in the U3 viral enhancer region but rather is the result of a cis-acting effect of the capsid-coding gag sequence. PMID:10559365

  1. Construction and characterization of the recombinant Moloney murine leukemia viruses bearing the mouse Fv-4 env gene.

    PubMed Central

    Masuda, M; Yoshikura, H

    1990-01-01

    A nucleotide sequence of the mouse Fv-4 env gene was completed. Structural comparison revealed a close relationship of Fv-4 to the ecotropic Cas-Br-E murine leukemia virus isolated from a wild mouse in southern California. Various portions of the env gene of Moloney murine leukemia virus were replaced by the corresponding Fv-4 env sequence to construct recombinant murine leukemia virus clones. Infectivity of these recombinants was checked by the S+L- cell focus induction assay and the XC cell syncytium formation assay. Recombinants bearing the following Fv-4 env sequence retained ecotropic infectivity; the AccI-BamHI and BamHI-BalI regions coding for the N- and C-terminal halves of Fv-4 gp70SU, respectively; and the BalI-NcoI region encoding the cleavage site between gp70SU and p15(E)TM of the Fv-4 env. However, when the Fv-4 sequence was substituted for the p15(E)TM-coding NcoI-EcoRV region or the AccI-EcoRV region covering almost the entire env gene, infectivity was undetectable in our assays. The recombinant clone containing the Fv-4 AccI-EcoRV region, i.e., almost the entire Fv-4 env sequence, was introduced with pSV2neo into NIH 3T3 cells, and a G418r cell line named NIH(Fv4)-2 was isolated. The NIH(Fv4)-2 cell released viral particles that contained reverse transcriptase, Fv-4 env molecules as well as the other viral proteins, and viral genomic RNA. However, proviral DNA synthesis was not detected upon inoculation of this virus in NIH 3T3 cells. The loss of infectivity of the recombinant virus bearing the Fv-4 AccI-EcoRV region appeared to be caused by failure in an early step of replication. Images PMID:2304138

  2. Tumorigenic Potential of a Recombinant Retrovirus Containing Sequences from Moloney Murine Leukemia Virus and Feline Leukemia Virus

    PubMed Central

    Starkey, C. R.; Lobelle-Rich, P. A.; Granger, S.; Brightman, B. K.; Fan, H.; Levy, L. S.

    1998-01-01

    A recombinant retrovirus, termed MoFe2-MuLV, was constructed in which the U3 region of T-lymphomagenic Moloney murine leukemia virus (Mo-MuLV) was replaced by that of FeLV-945, a provirus of unique long terminal repeat (LTR) structure identified only in non-T-cell, non-B-cell lymphomas of the domestic cat. The LTR of FeLV-945 is unusual in that it contains only a single copy of the transcriptional enhancer followed 25 bp downstream by a 21-bp sequence in triplicate in tandem. Infectivity of MoFe2-MuLV was demonstrated in vitro in SC-1 cells and in vivo in neonatal NIH-Swiss mice. Tumors occurred in MoFe2-MuLV-infected animals following a latency period of 4 to 10 months (average, 6 months). The results of Southern blot analysis of the T-cell receptor beta locus demonstrated that all tumors were lymphomas of T-cell origin. MoFe2-MuLV LTRs were amplified by PCR from tumor DNA and were characterized by nucleotide sequence analysis. LTRs from the tumors that occurred with relatively shorter latency predominantly retained the original MoFe2-MuLV sequence intact and unaltered. Tumors that occurred with relatively longer latency contained LTRs that also retained the 21-bp sequence triplication characteristic of the original virus but had acquired various duplications of enhancer sequences. The repeated identification of enhancer duplications in late-appearing tumors suggests that the duplication affords a selective advantage, although apparently not in the efficient induction of T-cell lymphoma. Proto-oncogenes known to be targets of insertional mutagenesis in the majority of Mo-MuLV-induced tumors or in feline non-T-cell, non-B-cell lymphomas were shown not to be rearranged in any tumor examined. Mink cell focus-inducing (MCF) proviral DNA was readily detectable in some, but not all, tumors. The presence or absence of MCF did not correlate with the kinetics of tumor induction. These studies indicate that the single-enhancer, triplication-containing FeLV LTR, typical of

  3. Domain structure of the Moloney murine leukemia virus reverse transcriptase: mutational analysis and separate expression of the DNA polymerase and RNase H activities.

    PubMed Central

    Tanese, N; Goff, S P

    1988-01-01

    The reverse transcriptase of Moloney murine leukemia virus, like that of all retroviruses, exhibits a DNA polymerase activity capable of synthesis on RNA or DNA templates and an RNase H activity with specificity for RNA in the form of an RNA.DNA hybrid. We have generated a library of linker insertion mutants of the Moloney murine leukemia virus enzyme expressed in bacteria and assayed these mutants for both enzymatic activities. Those mutations affecting the DNA polymerase activity were clustered in the 5'-proximal two-thirds of the gene, and those affecting RNase H were in the remaining 3' one-third. Based on these maps, plasmids were made that expressed each one of the domains separately; assays of the proteins encoded by these plasmids showed that each domain exhibited only the expected activity. Images PMID:2450347

  4. Evidence that a downstream pseudoknot is required for translational read-through of the Moloney murine leukemia virus gag stop codon.

    PubMed Central

    Wills, N M; Gesteland, R F; Atkins, J F

    1991-01-01

    Approximately 5% of the ribosomes translating the gag gene of murine leukemia viruses read through the UAG terminator and translate the in-frame pol gene to produce the gag-pol fusion polyprotein, the sole source of the pol gene products. We show that a pseudoknot located eight nucleotides 3' of the UAG codon in the Moloney murine leukemia virus is required for read-through. This requirement is markedly different from that known to be involved in other cases of read-through but surprisingly similar to some stimulatory sequences known to promote ribosomal frameshifting. Images PMID:1871115

  5. Identification of a gag-encoded cytotoxic T-lymphocyte epitope from FBL-3 leukemia shared by Friend, Moloney, and Rauscher murine leukemia virus-induced tumors.

    PubMed Central

    Chen, W; Qin, H; Chesebro, B; Cheever, M A

    1996-01-01

    FBL-3 is a highly immunogenic murine leukemia of C57BL/6 origin induced by Friend murine leukemia virus (MuLV). Immunization of C57BL/6 mice with FBL-3 readily elicits CD8+ cytotoxic T lymphocytes (CTL) capable of lysing FBL-3 as well as syngeneic leukemias induced by Moloney and Rauscher MuLV. The aim of this current study was to identify the immunogenic epitope(s) recognized by the FBL-3-specific CD8+ CTL. A series of FBL-3-specific CD8+ CTL clones were generated from C57BL/6 mice immunized to FBL-3. The majority of CTL clones (32 of 38) were specific for F-MuLV gag-encoded antigen. By using a series of recombinant vaccinia viruses expressing full-length and truncated F-MuLV gag genes, the antigenic epitope recognized by the FBL-3 gag-specific CTL clones, as well as by bulk-cultured CTL from spleens of mice immune to FBL-3, was localized to the leader sequence of gPr80gag protein. The precise amino acid sequence of the CTL epitope in the leader sequence was identified as CCLCLTVFL (positions 85-93) by examining lysis of targets incubated with a series of synthetic leader sequence peptides. No evidence of other CTL epitopes in the gPr80gag or Pr65gag core virion structural polyproteins was found. The identity of CCLCLTVFL as the target peptide was validated by showing that immunization with the peptide elicited CTL that lysed FBL-3. The CTL elicited by the Gag peptide also specifically lysed syngeneic leukemia cells induced by Moloney and Rauscher MuLV (MBL-2 and RBL-5). The transmembrane peptide was shown to be the major gag-encoded antigenic epitope recognized by bulk-cultured CTL derived from C57BL/6 mice immunized to MBL-2 or RBL-5. Thus, the CTL epitope of FBL-3 is localized to the transmembrane anchor domain of the nonstructural Gag polyprotein and is shared by leukemia/lymphoma cell lines induced by Friend, Moloney, and Rauscher MuLV. PMID:8892898

  6. Second site mutation in the virus envelope expands the host range of a cytopathic variant of Moloney murine leukemia virus.

    PubMed

    Ferrarone, John; Knoper, Ryan C; Li, Randolph; Kozak, Christine A

    2012-11-10

    Spl574 MLV (murine leukemia virus) is a variant of Moloney ecotropic MLV (MoMLV) that is cytopathic in Mus dunni cells and restricted by other mouse cells. Its host range and cytopathicity are due to a mutation, S82F, at a site critical for binding to the CAT-1 receptor. To identify residues that affect affinity for receptor variants, virus with S82F was passed in restrictive cells. The env genes of the adapted viruses contained 18 novel mutations, including one, E114G, present in 6 of 30 sequenced envs. MoMLV-E114G efficiently infected all mouse cells as well as ecotropic MLV resistant Chinese hamster cells. Virus with E114G and S82F induced large multinucleated syncytia in NIH 3T3 and SC-1 cells as well as M. dunni cells. Inoculation of Mo-S82F,E114G into mice produced lymphomas typical of MoMLV. Residues at env position 114 are thus important determinants of host range, and E114G suppresses host range restriction due to S82F, but does not affect S82F-governed cytopathicity.

  7. Activation of the prolactin receptor gene by promoter insertion in a Moloney murine leukemia virus-induced rat thymoma.

    PubMed Central

    Barker, C S; Bear, S E; Keler, T; Copeland, N G; Gilbert, D J; Jenkins, N A; Yeung, R S; Tsichlis, P N

    1992-01-01

    The prolactin receptor (Prlr) and growth hormone receptor (Ghr) genes and the Moloney murine leukemia virus integration-2 (Mlvi-2) locus were mapped to mouse chromosome 15 and human chromosome 5 bands p12-p14. To examine the potential relationship between Mlvi-2 and the genes encoding the growth hormone receptor and the prolactin receptor, we determined the chromosomal location of all three loci in the rat, using a panel of rat-mouse somatic cell hybrids, and in the mouse, using a panel of (C57BL/6J x Mus spretus)F1 x C57BL/6J interspecific backcross mice. These analyses revealed that Ghr, Prlr, and Mlvi-2 map to chromosome 2 in the rat and to chromosome 15 in the mouse, in close proximity with each other. Pulsed-field gel electrophoresis of rat genomic DNA showed no overlaps between the gene encoding the prolactin receptor and the remaining loci. Moreover, expression of the prolactin receptor was not affected by provirus insertion in Mlvi-2. During these studies, however, we detected one T-cell lymphoma line (2779) in which the prolactin receptor gene was activated by provirus integration. Sequence analysis of polymerase chain reaction-derived cDNA clones showed that the prolactin receptor RNA message initiates at the 5' long terminal repeat and utilizes the splice donor site 5' of the gag gene to splice the viral sequences onto exon 1 of the prolactin receptor. This message is predicted to encode the intact prolactin receptor protein product. Exposure of the T-cell lymphoma line 2779 to prolactin promoted cellular proliferation. Images PMID:1404614

  8. Yeast system as a model to study Moloney murine leukemia virus integrase: expression, mutagenesis and search for eukaryotic partners.

    PubMed

    Vera, Jorge; Parissi, Vincent; García, Andrea; Zúñiga, Roberto; Andreola, Marie-Line; Caumont-Sarcos, Anne; Tarrago-Litvak, Laura; Leon, Oscar

    2005-09-01

    Moloney murine leukemia virus (M-MuLV) integrase (IN) catalyses the insertion of the viral genome into the host chromosomal DNA. The limited solubility of the recombinant protein produced in Escherichia coli led the authors to explore the use of Saccharomyces cerevisiae for expression of M-MuLV IN. IN was expressed in yeast and purified by chromatography on nickel-NTA agarose. IN migrated as a single band in SDS-PAGE and did not contain IN degradation products. The enzyme was about twofold more active than the enzyme purified from E. coli and was free of nucleases. Using the yeast system, the substitution of the putative catalytic amino acid Asp184 by alanine was also analysed. The mutated enzyme was inactive in the in vitro assays. This is the first direct demonstration that mutation of Asp184 inactivates M-MuLV IN. Finally, S. cerevisiae was used as a model to assess the ability of M-MuLV IN to interact with eukaryotic protein partners. The expression of an active M-MuLV IN in yeast strains deficient in RAD52 induced a lethal effect. This phenotype could be attributed to cellular damage, as suggested by the viability of cells expressing inactive D184A IN. Furthermore, when active IN was expressed in a yeast strain lacking the ySNF5 transcription factor, the lethal effect was abolished, suggesting the involvement of ySNF5 in the cellular damage induced by IN. These results indicate that S. cerevisiae could be a useful model to study the interaction of IN with cellular components in order to identify potential counterparts of the natural host.

  9. Characterization of a progressive neurodegenerative disease induced by a temperature-sensitive Moloney murine leukemia virus infection.

    PubMed Central

    Bilello, J A; Pitts, O M; Hoffman, P M

    1986-01-01

    A progressive neurodegenerative disease occurred following infection of mice with a temperature-sensitive (ts) isolate of Moloney (Mo) murine leukemia virus (MuLV), ts Mo BA-1 MuLV. This NB-tropic ecotropic MuLV, which was ts for a late function, induced a syndrome of tremor, weakness of the hind limbs, and spasticity following infection of several strains of laboratory neonatal mice, including NFS, C3H/He, CBA, SJL, and BALB/c. The latent period of 8 to 16 weeks was considerably longer than that observed for the acute paralytic diseases observed following neonatal infection with other ts Mo-MuLV, rat-passaged Friend MuLV, and some wild mouse ecotropic MuLVs. Spongiform pathology without inflammation and degeneration of neurons devoid of budding virions occurred in the cerebellar grey matter, brain stem, and upper spinal cord; but lower spinal cord anterior horn cells were less obviously affected than in other MuLV-associated neuroparalytic syndromes. ts Mo BA-1 MuLV differed from other ts Mo-MuLV mutants that are capable of inducing a neuroparalytic syndrome in that while infected nervous system tissue contained high levels of MuLV p30 and gp70, no evidence of precursor accumulation or abnormal processing of MuLV p30 or gp70 could be demonstrated. The localization of virus within the nervous system suggests that direct neuronal infection may not be the etiologic mechanism in this MuLV-induced neurodegenerative disease. Images PMID:3735486

  10. Generation of glucocorticoid-responsive Moloney murine leukemia virus by insertion of regulatory sequences from murine mammary tumor virus into the long terminal repeat.

    PubMed Central

    Overhauser, J; Fan, H

    1985-01-01

    The glucocorticoid-regulatory sequences from the murine mammary tumor virus long terminal repeat (MMTV LTR) were introduced into the LTR of Moloney murine leukemia virus (M-MuLV) by recombinant DNA techniques. The site of insertion was in the M-MuLV LTR U3 region at -150 base pairs with respect to the RNA cap site. Infectious M-MuLVs carrying the altered LTRs (Mo + MMTV M-MuLVs) were recovered by transfection of proviral clones into NIH-3T3 cells. The Mo + MMTV M-MuLVs were hormonally responsive in that infection was 3 logs more efficient when performed in the presence of dexamethasone, irrespective of the orientation of the inserted MMTV sequences. However, even in the presence of hormone, the Mo + MMTV M-MuLVs were less infectious than wild-type M-MuLV. In contrast to the large effect on infectivity, dexamethasone induced virus-specific RNA levels in chronically Mo + MMTV M-MuLV-infected cells only two- to fourfold. Fusion plasmids between the altered LTRs and the bacterial chloramphenicol acetyltransferase gene allowed the investigation of LTR promoter strength by the transient chloramphenicol acetyltransferase expression assay. The chloramphenicol acetyltransferase assays indicated that the insertion of MMTV sequences into the M-MuLV LTR reduced promoter activity in the absence of glucocorticoids but that promoter activity could be induced two- to fivefold by dexamethasone. The Mo + MMTV M-MuLVs were also tested for the possibility that viral DNA synthesis or integration during initial infection was enhanced by dexamethasone. However, no significant difference was detected between cultures infected in the presence or absence of hormone. The insertion of MMTV sequences into an M-MuLV LTR deleted of its enhancer sequences did not yield infectious virus or active promoters, even in the presence of dexamethasone. Images PMID:2983110

  11. Point mutations in the Moloney murine leukemia virus enhancer identify a lymphoid-specific viral core motif and 1,3-phorbol myristate acetate-inducible element.

    PubMed Central

    Speck, N A; Renjifo, B; Hopkins, N

    1990-01-01

    The transcriptional enhancer of the Moloney murine leukemia virus (MoMLV) is organized as a 75-base-pair repeat, and in each copy of the repeat there are multiple binding sites for nuclear factors. We have introduced point mutations into each of the known nuclear factor-binding sites in the MoMLV enhancer, in both copies of the direct repeat, and have analyzed the transcriptional activity conferred by the mutated enhancers by transient-expression assays in both hematopoietic and nonhematopoietic cell lines. Mutation of individual binding sites in the MoMLV enhancer has moderate effects (less than 2-fold to 20-fold) on transcription in six independent cell lines. Several mutations decreased transcription from the MoMLV enhancer ubiquitously (the leukemia virus factor b site and the glucocorticoid response element), whereas others affected transcription specifically in lymphoid cell lines (core motif) or, more significantly, in fibroblasts (nuclear factor 1 site). The transcriptional activity of the MoMLV enhancer can be induced 8- to 10-fold by 1,3-phorbol myristate acetate in Jurkat T cells. Mutations in any of three adjacent binding sites (leukemia virus factor b and c sites and the core motif) within a 28-base-pair region in the center of the direct repeat sequence of the MoMLV enhancer completely attenuate the response to 1,3-phorbol myristate acetate. Images PMID:2104942

  12. Mutations altering the moloney murine leukemia virus p12 Gag protein affect virion production and early events of the virus life cycle.

    PubMed Central

    Yuan, B; Li, X; Goff, S P

    1999-01-01

    The p12 Gag protein of Moloney murine leukemia virus is a small polypeptide of unknown function, containing two proline-rich motifs. To determine its role in replication, we introduced a series of deletion and alanine-scanning substitution mutations throughout the p12 coding region of a proviral DNA, and characterized the phenotypes of the resulting mutant viruses. Complete deletion of p12 and mutations affecting the PPPY motif caused substantial reduction in the yield of virions and a modest reduction in Gag processing. Proteolytic cleavage of the R-peptide from the cytoplasmic tail of the envelope protein TM was abolished in these mutants, suggesting that the PPPY motif is crucial for the viral protease to access the TM tail. The resulting virions were non-infectious, and unable to initiate DNA synthesis in infected cells. Mutants with alterations in both the N- and C-terminal portions of p12 exhibited a distinct phenotype. The production of virions and processing of Gag, Pol and Env precursors were normal. The viruses were able to direct synthesis of linear viral DNA, but there was almost no detectable circular DNAs or LTR-LTR junction. These data suggest that p12 plays a critical role in the early events of the virus life cycle. PMID:10469649

  13. Improvement of retroviral retargeting by using amino acid spacers between an additional binding domain and the N terminus of Moloney murine leukemia virus SU.

    PubMed Central

    Valsesia-Wittmann, S; Morling, F J; Nilson, B H; Takeuchi, Y; Russell, S J; Cosset, F L

    1996-01-01

    We previously reported a strategy to redirect the retroviral host range by expressing single-chain antibodies (S. J. Russell, R. E. Hawkins, and G. Winter, Nucleic Acids Res. 21:1081-1085, 1993) or ligands (F.-L. Cosset, F. J Morling, Y. Takeuchi, R. A. Weiss, M. K. L. Collins, and S. J. Russell, J. Virol. 69:6314-6322, 1995) at the N terminus of Moloney murine leukemia virus (MoMLV) surface proteins (SU). Although such chimeric envelopes were able to bind the new receptors, the transduction efficiency of retargeted viruses was generally low. We hypothesized that conformational rearrangements of envelope glycoproteins were not optimally triggered following binding, and to overcome these postbinding blocks, we have generated here a set of chimeric MoMLV-derived envelopes targeted to the Ram-1 phosphate transporter in which we have varied the spacing between the Ram-1-binding domain and the MoMLV SU. All of the recombinant envelopes were correctly expressed on virions, and all bound efficiently to Ram-1. However, the interdomain spacing greatly affected the efficiency of gene transfer by retroviral vectors that had bound to Ram-1 via their chimeric envelopes. Optimal interdomain spacing allowed a 100-fold-increased viral transduction via Ram-1 compared to our previous results. PMID:8627737

  14. X-ray crystal structure of the N-terminal region of Moloney murine leukemia virus integrase and its implications for viral DNA recognition.

    PubMed

    Guan, Rongjin; Aiyer, Sriram; Cote, Marie L; Xiao, Rong; Jiang, Mei; Acton, Thomas B; Roth, Monica J; Montelione, Gaetano T

    2017-04-01

    The retroviral integrase (IN) carries out the integration of a dsDNA copy of the viral genome into the host DNA, an essential step for viral replication. All IN proteins have three general domains, the N-terminal domain (NTD), the catalytic core domain, and the C-terminal domain. The NTD includes an HHCC zinc finger-like motif, which is conserved in all retroviral IN proteins. Two crystal structures of Moloney murine leukemia virus (M-MuLV) IN N-terminal region (NTR) constructs that both include an N-terminal extension domain (NED, residues 1-44) and an HHCC zinc-finger NTD (residues 45-105), in two crystal forms are reported. The structures of IN NTR constructs encoding residues 1-105 (NTR1-105 ) and 8-105 (NTR8-105 ) were determined at 2.7 and 2.15 Å resolution, respectively and belong to different space groups. While both crystal forms have similar protomer structures, NTR1-105 packs as a dimer and NTR8-105 packs as a tetramer in the asymmetric unit. The structure of the NED consists of three anti-parallel β-strands and an α-helix, similar to the NED of prototype foamy virus (PFV) IN. These three β-strands form an extended β-sheet with another β-strand in the HHCC Zn(2+) binding domain, which is a unique structural feature for the M-MuLV IN. The HHCC Zn(2+) binding domain structure is similar to that in HIV and PFV INs, with variations within the loop regions. Differences between the PFV and MLV IN NEDs localize at regions identified to interact with the PFV LTR and are compared with established biochemical and virological data for M-MuLV. Proteins 2017; 85:647-656. © 2016 Wiley Periodicals, Inc.

  15. Arm-specific cleavage and mutation during reverse transcription of 2΄,5΄-branched RNA by Moloney murine leukemia virus reverse transcriptase

    PubMed Central

    Döring, Jessica

    2017-01-01

    Abstract Branchpoint nucleotides of intron lariats induce pausing of DNA synthesis by reverse transcriptases (RTs), but it is not known yet how they direct RT RNase H activity on branched RNA (bRNA). Here, we report the effects of the two arms of bRNA on branchpoint-directed RNA cleavage and mutation produced by Moloney murine leukemia virus (M-MLV) RT during DNA polymerization. We constructed a long-chained bRNA template by splinted-ligation. The bRNA oligonucleotide is chimeric and contains DNA to identify RNA cleavage products by probe hybridization. Unique sequences surrounding the branchpoint facilitate monitoring of bRNA purification by terminal-restriction fragment length polymorphism analysis. We evaluate the M-MLV RT-generated cleavage and mutational patterns. We find that cleavage of bRNA and misprocessing of the branched nucleotide proceed arm-specifically. Bypass of the branchpoint from the 2΄-arm causes single-mismatch errors, whereas bypass from the 3΄-arm leads to deletion mutations. The non-template arm is cleaved when reverse transcription is primed from the 3΄-arm but not from the 2΄-arm. This suggests that RTs flip ∼180° at branchpoints and RNases H cleave the non-template arm depending on its accessibility. Our observed interplay between M-MLV RT and bRNA would be compatible with a bRNA-mediated control of retroviral and related retrotransposon replication. PMID:28160599

  16. Expression and survival significance of B-cell-specific Moloney murine leukemia virus integration site 1 and matrix metalloproteinase-9 in non-small-cell lung cancer

    PubMed Central

    Mu, Mingkui; Song, Yang; Zhang, Bin

    2016-01-01

    One of the main challenges in lung cancer research is identifying patients at high risk of progression and metastasis following surgical resection. In the present study, the prognostic significance of B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) and matrix metalloproteinase-9 (MMP9) in non-small-cell lung cancer (NSCLC) was evaluated. BMI1 and MMP9 expression in tumors from 132 surgical NSCLC patients [squamous cell carcinoma (SCC), n=79; and adenocarcinoma (AD), n=53] was evaluated by immunohistochemistry. The clinical significance was determined using multivariate Cox regression analysis, Kaplan-Meier curves and the log-rank test. High BMI1 expression was more frequent in SCC compared with that in AD (P=0.015). Comparisons between the expression of BMI1 and that of other known biological markers revealed that the expression of BMI1 was correlated with that of MMP9 (χ2=4.241, P=0.039) in SCC. Although an association was not identified between high BMI1 expression and overall survival (OS) in NSCLC or AD, high BMI1 expression was an unfavorable predictor of survival in SCC according to the survival curves (P=0.038). In addition, combined high BMI1 and MMP9 expression levels were significantly correlated with SCC nodal/distant metastasis (χ2=6.392, P=0.014). Multivariate Cox proportional model analysis demonstrated that this combined marker was an independent prognostic indicator of OS in SCC (P=0.025; hazard ratio = 12.963; 95% confidence interval: 1.142–7.637). Therefore, this study demonstrated that combined BMI1 and MMP9 expression may be used as a marker for the progression and metastasis of SCC. These results may aid in the elucidation of the potential mechanism underlying the involvement of BMI1 and MMP9 in tissue-specific SCC progression. PMID:27900059

  17. Generation and characterization of a recombinant Moloney murine leukemia virus containing the v-myc oncogene of avian MC29 virus: in vitro transformation and in vivo pathogenesis.

    PubMed Central

    Brightman, B K; Pattengale, P K; Fan, H

    1986-01-01

    A new retrovirus consisting of the v-myc oncogene sequences of avian MC29 virus inserted into the genome of Moloney murine leukemia virus (M-MuLV) was generated. This was accomplished by constructing a recombinant DNA clone containing the desired organization, introducing the recombinant DNA into mouse NIH 3T3 cells, and superinfecting the cells with replication-competent M-MuLV. The construction was designed so that an M-MuLV gag-myc fusion protein would be produced. The resulting virus, M-MuLV(myc), morphologically transformed uninfected NIH 3T3 cells. Stocks of M-MuLV(myc)-M-MuLV were infected into secondary mouse embryo cultures. M-MuLV(myc) induced striking growth and proliferation of hematopoietic cells. These cells were of the myeloid lineage by morphology, phagocytic properties, and surface staining with Mac-1 and Mac-2 monoclonal antibodies. They resembled mature macrophages, although they displayed minor properties of immaturity. The myeloid cells were transformed in comparison with uninfected myeloid cells since they were less adherent and had unlimited proliferative capacity and reduced growth factor requirements. The transformed myeloid cells with proliferative potential were actually myeloid progenitors which apparently underwent terminal differentiation to macrophages. It was possible to derive a permanent line of factor-independent macrophages from M-MuLV(myc)-transformed myeloid cells. M-MuLV(myc) also immortalized and morphologically transformed mouse embryo fibroblasts. These in vitro properties closely resembled the biological activity of MC29 virus in avian cells and suggested that the nature of the v-myc oncogene was an important determinant in transformation specificity. Neonatal NIH Swiss mice inoculated intraperitoneally with M-MuLV(myc)-M-MuLV only developed lymphoblastic lymphoma characteristic of the M-MuLV helper alone, and no acute fibrosarcomas or myeloid tumors resulted. In light of the strong myeloid transformation observed in vitro

  18. Site-directed mutagenesis of the codon for Ile-25 in gPr80env alters the neurovirulence of ts1, a mutant of Moloney murine leukemia virus TB.

    PubMed Central

    Szurek, P F; Floyd, E; Yuen, P H; Wong, P K

    1990-01-01

    ts1, a spontaneous temperature-sensitive mutant of Moloney murine leukemia virus TB, causes hind-limb paralysis in mice. A Val-25----Ile substitution in gPr80env is responsible for temperature sensitivity, inefficient processing of gPr80env, and neurovirulence. In this study, the Ile-25 in gPr80env was replaced with Thr, Ala, Leu, Gly, and Glu by site-directed mutagenesis of the codon for Ile-25 to generate a new set of mutant viruses, i.e., ts1-T, -A, -L, -G, and -E, respectively. The phenotypic characteristics of these mutant viruses differed from those of ts1. For each mutant, the degree of temperature sensitivity was correlated with the degree of inefficient processing of gPr80env, and the following rank order was observed for both parameters: ts1-E greater than ts1-G greater than ts1-L greater than ts1-A greater than ts1 greater than ts1-T. In FVB/N mice, mutant viruses of low and intermediate temperature sensitivity and inefficiency in processing of gPr80env were neurovirulent and consistently caused mutant-specific disease profiles: ts1-T caused severe whole-body tremor, ts1-A generally caused hind-limb paralysis, and ts1-L generally caused a delayed-onset paraparesis. By 150 days postinfection, FVB/N mice that were infected with ts1-G and -E, mutants of high temperature sensitivity and inefficiency in processing of gPr80env, had lymphoid leukemia instead of a neurological disease. These results suggest that the dynamics of gPr80env processing are important in determining the neurovirulent phenotype in vivo. Images PMID:2214016

  19. Identification of amino acids inserted during suppression of UAA and UGA termination codons at the gag-pol junction of Moloney murine leukemia virus.

    PubMed Central

    Feng, Y X; Copeland, T D; Oroszlan, S; Rein, A; Levin, J G

    1990-01-01

    Expression of the murine leukemia virus pol gene occurs by translational readthrough of an in-frame UAG codon between the gag and pol coding regions. In a previous study, we mutated the UAG codon to UAA or UGA and demonstrated that both of these termination codons could be suppressed in reticulocyte lysates and in infected cells with the same efficiency as UAG. We now report the identity of the amino acids inserted in vitro in response to UAA and UGA in fusion products containing the gag-pol junction region. The results show that UAA, like UAG, directs the incorporation of glutamine, whereas UGA directs the incorporation of three amino acids, arginine, cysteine, and tryptophan. To our knowledge, this is the first report indicating misreading of UAA as glutamine and UGA as arginine and cysteine in higher eukaryotes. Interestingly, although our protein synthesis system presumably contains other known UAG and UGA suppressors, these tRNAs did not suppress the termination codons in our experiments. Thus, it seems possible that the sequence surrounding the gag-pol junction not only promotes suppression but also helps determine which tRNAs function in suppression. Images PMID:2247457

  20. The conserved His8 of the Moloney murine leukemia virus Env SU subunit directs the activity of the SU-TM disulphide bond isomerase

    SciTech Connect

    Li Kejun; Zhang, Shujing; Kronqvist, Malin; Ekstroem, Maria; Wallin, Michael; Garoff, Henrik . E-mail: henrik.garoff@cbt.ki.se

    2007-04-25

    Murine leukemia virus (MLV) fusion is controlled by isomerization of the disulphide bond between the receptor-binding surface (SU) and fusion-active transmembrane subunits of the Env-complex. The bond is in SU linked to a CXXC motif. This carries a free thiol that upon receptor binding can be activated (ionized) to attack the disulphide and rearrange it into a disulphide isomer within the motif. To find out whether His8 in the conserved SPHQ sequence of Env directs thiol activation, we analyzed its ionization in MLV vectors with wtEnv and Env with His8 deleted or substituted for Tyr or Arg, which partially or completely arrests fusion. The ionization was monitored by following the pH effect on isomerization in vitro by Ca{sup 2+} depletion or in vivo by receptor binding. We found that wtEnv isomerized optimally at slightly basic pH whereas the partially active mutant required higher and the inactive mutants still higher pH. This suggests that His8 directs the ionization of the CXXC thiol.

  1. Chromatin structure of recombinant Moloney murine leukemia virus proviral DNAs that contain tax-responsive sequences from human T-cell lymphotropic virus type II in the presence and absence of tax.

    PubMed Central

    Kitado, H; Fan, H

    1989-01-01

    Human T-cell lymphotropic virus types I and II (HTLV-I and HTLV-II) are replication-competent retroviruses which contain two additional regulatory proteins, tax and rex. tax is a transcriptional transactivator of the HTLV-I or HTLV-II long terminal repeat (LTR) and also of some heterologous promoters. To investigate the mechanism of tax transactivation, we used chimeric Moloney murine leukemia viruses (M-MuLVs) with LTRs containing tax-responsive sequences from the HTLV-II LTR (nucleotides -273 to -32). Mo+HTLV-II+ M-MuLV contained the HTLV II sequences inserted into the wild-type M-MuLV LTR at nucleotide -150, whereas delta Mo+HTLV-II+ M-MuLV contained the same sequences inserted into an M-MuLV LTR lacking its own enhancer region. HTLV-II tax (tax II)-positive mouse cells (15S-5a) infected with Mo+HTLV-II+ M-MuLV or delta Mo+HTLV-II+ M-MuLV showed higher rates of viral transcription in nuclear run-on assays than did infected tax-negative NIH 3T3 cells. The chromatin structure of these viruses was investigated by high-resolution mapping of DNase I-hypersensitive (HS) sites. Three prominent HS sites were associated with HTLV-II sequences in proviral chromatin both in tax-positive and in tax-negative cells. The spacing resembled that of the 21-base-pair (bp) repeats, but the HS sites were displaced approximately 50 bp upstream of the 21-bp repeats. This suggested that cellular proteins bound to the HTLV-II sequences in the presence or absence of tax. No direct effect of tax on chromatin structure was found. These in vivo results were consistent with results of in vitro DNase footprinting studies performed by other investigators. Images PMID:2786092

  2. Temperature-sensitive viral RNA expression in Moloney murine sarcoma virus ts110-infected cells.

    PubMed Central

    Hamelin, R; Brizzard, B L; Nash, M A; Murphy, E C; Arlinghaus, R B

    1985-01-01

    We examined the mos-specific intracellular RNA species in 6m2 cells, an NRK cell line nonproductively infected with the ts110 mutant of Moloney murine sarcoma virus. These cells present a normal phenotype at 39 degrees C and a transformed phenotype at 28 or 33 degrees C, expressing two viral proteins, termed P85gag-mos and P58gag, at 28 to 33 degrees C, whereas only P58gag is expressed at 39 degrees C. It has been previously shown that 6m2 cells contain two virus-specific RNA species, a 4.0-kilobase (kb) RNA coding for P58gag and a 3.5-kb RNA coding for P85gag-mos. Using both Northern blot and S1 nuclease analyses, we show here that the 3.5-kb RNA is the predominant viral RNA species in 6m2 cells grown at 28 degrees C, whereas only the 4.0-kb RNA is detected at 39 degrees C. During temperature shift experiments, the 3.5-kb RNA species disappears after a shift from 28 to 39 degrees C and is detected again after a shift back from 39 to 28 degrees C. By Southern blot analysis, we have detected only one ts110 proviral DNA in the 6m2 genome. This observation, as well as previously published heteroduplex and S1 nuclease analyses which showed that the 3.5-kb RNA species lacks about 430 bases found at the gag gene-mos gene junction in the 4.0-kb RNA, suggests that the 3.5-kb RNA is a splicing product of the 4.0-kb RNA. The absence of the 3.5-kb RNA when 6m2 cells are grown at 39 degrees C indicates that the splicing reaction is thermosensitive. The splicing defect of the ts110 Moloney murine sarcoma virus viral RNA in 6m2 cells cannot be complemented by acute Moloney murine leukemia virus superinfection, since no 3.5-kb ts110 RNA was detected in acutely superinfected 6m2 cells maintained at 39 degrees C. The spliced Moloney murine leukemia virus env mRNA, however, is found in acutely infected cells maintained at 39 degrees C, suggesting that the lack of ts110 viral RNA splicing at 39 degrees C is not due to an obvious host defect. In sharp contrast, however, 6m2 cells

  3. Characterization of Moloney murine leukaemia virus/avian myeloblastosis virus chimeric reverse transcriptases.

    PubMed

    Yasukawa, Kiyoshi; Mizuno, Masaki; Inouye, Kuniyo

    2009-03-01

    Reverse transcriptases (RTs) from Moloney murine leukaemia virus (MMLV) and avian myeloblastosis virus (AMV) contain all the fingers, palm, thumb, connection and RNase H domains. The fingers, palm and thumb domains are thought to be involved in the reverse transcription activity, and the RNase H domain is in the RNase H activity. In this study, we characterized four chimeric RTs which comprise one of the fingers, palm, thumb and RNase H domains originated from AMV RT and the other three and connection domains originated from MMLV RT. Unexpectedly, all chimeric RTs exhibited the same characteristics: their specific reverse transcription activities decreased to less than 0.1% of that of MMLV RT, while their specific RNase H activities were approximately 20% of that of MMLV RT. The decreases in the two activities of the chimeric RTs were ascribed to the decreases in k(cat). Based on that the reverse transcription activity of MMLV RT was impaired by substituting its RNase H domain with that from AMV RT, we propose that in MMLV RT, there might be an interaction between the fingers/palm/thumb domain and the RNase H domain.

  4. Expression of the v-mos gene alters a Mr 55,000 protein during acute infection by Moloney murine sarcoma virus.

    PubMed Central

    Singh, B; Sparrow, J T; Hedge, A M; Arlinghaus, R B

    1986-01-01

    Infection of the rat myoblast cell line, L6E9, with Moloney murine sarcoma virus (Mo-MuSV) clone 124, altered a cellular protein of Mr 55,000 (P55) within 2 days of infection. The alteration of P55 was observed as a reduction in its steady-state level in cell extracts. The reduction of P55 correlated with the appearance of p37mos in infected cells. Except for P55 and one other protein, no change was detected in the total protein pattern of infected cells compared to uninfected cells, as judged by either immunoblots of one-dimensional NaDodSO4 gels or direct two-dimensional gel analysis. P55 levels were unchanged when L6E9 cells were infected with Moloney murine leukemia virus or several different transforming retroviruses. To determine the specificity of this v-mos-induced effect on P55, L6E9 cells were acutely infected with a temperature-sensitive variant (ts110) of Mo-MuSV. When these cells were shifted from 39 degrees C to 33 degrees C, which activates the gag-mos gene product, the P55 level dropped by greater than 50% within 2-3 hr. Conversely, with a shift in temperature from 33 degrees C to 39 degrees C, the cells' P55 level returned to normal within 5 hr, starting at 30 min after shift. These results clearly show that v-mos expression in acutely infected L6E9 cells alters the cellular protein, P55. Images PMID:3012522

  5. Purification of core-binding factor, a protein that binds the conserved core site in murine leukemia virus enhancers.

    PubMed Central

    Wang, S W; Speck, N A

    1992-01-01

    The Moloney murine leukemia virus causes thymic leukemias when injected into newborn mice. A major genetic determinant of the thymic disease specificity of the Moloney virus genetically maps to two protein binding sites in the Moloney virus enhancer, the leukemia virus factor b site and the adjacent core site. Point mutations introduced into either of these sites significantly shifts the disease specificity of the Moloney virus from thymic leukemia to erythroleukemia (N. A. Speck, B. Renjifo, E. Golemis, T. Frederickson, J. Hartley, and N. Hopkins, Genes Dev. 4:233-242, 1990). We have purified several polypeptides that bind to the core site in the Moloney virus enhancer. These proteins were purified from calf thymus nuclear extracts by selective pH denaturation, followed by chromatography on heparin-Sepharose, nonspecific double-stranded DNA-cellulose, and core oligonucleotide-coupled affinity columns. We have achieved greater than 13,000-fold purification of the core-binding factors (CBFs), with an overall yield of approximately 19%. Analysis of purified protein fractions by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis reveals more than 10 polypeptides. Each of the polypeptides was recovered from an SDS-polyacrylamide gel, and those in the molecular size range of 19 to 35 kDa were demonstrated to have core-binding activity. The purified CBFs were shown by DNase I footprint analyses to bind the core site in the Moloney virus enhancer specifically, and also to core motifs in the enhancers from a simian immunodeficiency virus, the immunoglobulin mu chain, and T-cell receptor gamma-chain genes. Images PMID:1309596

  6. ANTIGENS OF LEUKEMIAS INDUCED BY NATURALLY OCCURRING MURINE LEUKEMIA VIRUS: THEIR RELATION TO THE ANTIGENS OF GROSS VIRUS AND OTHER MURINE LEUKEMIA VIRUSES

    PubMed Central

    Geering, Gayla; Old, Lloyd J.; Boyse, Edward A.

    1966-01-01

    Leukemias can be induced in W/Fu inbred rats by neonatal inoculation of normal thymus cells of C58 mice. These leukemias are not transplantable to C58 mice or to adult W/Fu rats, but they can be kept in passage in W/Fu rats aged 0 to 7 days. Adult W/Fu rats inoculated repeatedly with these isogenic leukemias produce cytotoxic and precipitating antibodies. These antisera are of particular value in the analysis of the antigens of leukemia cells and of leukemia viruses because their mode of preparation precludes the formation of antibody against any normal constituents of the cell. Analysis based on the cytotoxic test indicates the presence of 2 distinct cell surface antigens in leukemias induced by Passage A Gross virus or occurring spontaneously in mice of high-incidence strains. All leukemias and other tissues known to contain G (Gross) leukemia antigen have both determinants, but certain leukemias of low-incidence strains have only 1 of them and so were previously classified G-. Immunoprecipitation with these antisera reveals the presence of a cellular antigen common to G+ cells and absent from G- cells; the same antigen can be demonstrated in ether-treated Gross virus, but not in intact virus. This antigen is present also in ether-treated preparations of the Friend, Moloney, and Rauscher leukemia viruses, but not in Bittner (mammary tumor) virus. Thus it may be regarded as a group-specific antigen of murine leukemia viruses, in contrast to the type-specific cellular antigens demonstrable by the cytotoxic test. Four additional antigens associated with leukemias induced by wild-type Gross virus have been demonstrated by immunoprecipitation, but their relation to viral and cellular antigens has not been determined. PMID:4288480

  7. Cellular Moloney murine sarcoma (c-mos) sequences are hypermethylated and transcriptionally silent in normal and transformed rodent cells

    SciTech Connect

    Gattoni, S.; Kirschmeier, P.; Weinstein, I.B.; Escobedo, J.; Dina, D.

    1982-01-01

    Moloney murine sarcoma virus carries an oncogenic sequence (v-mos) which is homologous to a single copy gene (c-mos) present in the normal cells of several vertebrate species. Because of the possible significance of c-mos sequences in normal development and malignant transformation induced by physical or chemical agents, the authors examined the state of integration, methylation, and transcriptional activity of c-mos sequences in a variety of normal rodent tissues, normal cell lines, or cell lines transformed by radiation or chemical carcinogens. DNA-DNA hybridization, utilizing the Southern blotting technique and a plasmid-derived DNA probe representing the v-mos sequence, gave no evidence for rearrangements of the c-mos sequence in the DNAs obtained from these diverse cell types. Parallel studies employing the restriction enzyme isoschizomers HpaII and MspI indicated that in all of these cell types the c-mos sequences were heavily methylated. In addition, analysis of cellular RNAs by blot hybridization with the v-mos probe failed to detect evidence of transcription of the c-mos sequences in any of these cell types. This was in contrast to a Moloney sarcoma virus-transformed cell line in which they found that the integrated v-mos sequence was both undermethylated and extensively transcribed. Thus, it would appear that c-mos sequences do not play a role in the transformation of rodent cells by chemical or physical agents, although the possible role of other endogenous onc sequences remains to be determined.

  8. Comparative Analysis of HIV-1 and Murine Leukemia Virus Three-Dimensional Nuclear Distributions

    PubMed Central

    Quercioli, Valentina; Di Primio, Cristina; Casini, Antonio; Mulder, Lubbertus C. F.; Vranckx, Lenard S.; Borrenberghs, Doortje; Gijsbers, Rik; Debyser, Zeger

    2016-01-01

    Recent advances in fluorescence microscopy allow three-dimensional analysis of HIV-1 preintegration complexes in the nuclei of infected cells. To extend this investigation to gammaretroviruses, we engineered a fluorescent Moloney murine leukemia virus (MLV) system consisting of MLV-integrase fused to enhanced green fluorescent protein (MLV-IN-EGFP). A comparative analysis of lentiviral (HIV-1) and gammaretroviral (MLV) fluorescent complexes in the nuclei of infected cells revealed their different spatial distributions. This research tool has the potential to achieve new insight into the nuclear biology of these retroviruses. PMID:26962222

  9. A Novel Subgenomic Murine Leukemia Virus RNA Transcript Results from Alternative Splicing

    PubMed Central

    Déjardin, Jérôme; Bompard-Maréchal, Guillaume; Audit, Muriel; Hope, Thomas J.; Sitbon, Marc; Mougel, Marylène

    2000-01-01

    Here we show the existence of a novel subgenomic 4.4-kb RNA in cells infected with the prototypic replication-competent Friend or Moloney murine leukemia viruses (MuLV). This RNA derives by splicing from an alternative donor site (SD′) within the capsid-coding region to the canonical envelope splice acceptor site. The position and the sequence of SD′ was highly conserved among mammalian type C and D oncoviruses. Point mutations used to inactivate SD′ without changing the capsid-coding ability affected viral RNA splicing and reduced viral replication in infected cells. PMID:10729146

  10. Monoclonal antibody against IFN-gamma inhibits Moloney murine sarcoma virus-specific cytotoxic T lymphocyte differentiation

    SciTech Connect

    Zanovello, P.; Vallerani, E.; Biasi, G.; Landolfo, S.; Collavo, D.

    1988-02-15

    The role of autochthonous IFN- production was evaluated in immune reactions to Moloney murine sarcoma virus (M-MSV)-induced tumors which are characterized by spontaneous regression mainly caused by virus-specific CTL activity. A functional IFN- depletion, induced by repeated administration of mAb anti-IFN- at the site of virus inoculation, prevented tumor regression in M-MSV-injected mice. Moreover, this antibody inhibited in vitro both proliferation and differentiation of M-MSV-specific T lymphocytes obtained in bulk cultures, but not growth and lytic activity of the already differentiated virus-specific CTL clone CHM-14 stimulated with rIL-2 and relevant tumor Ag. In addition, in mice receiving mAb treatment the frequency of M-MSV-specific CTL precursors, evaluated by means of limiting dilution analysis, was strongly reduced in comparison with that of control mice injected only with virus. Because CTL secrete IFN- following antigenic stimulation, the possibility that non-T effector cells recruited by this lymphokine might mediate tumor regression was also considered. Adoptive immunotherapy experiments, performed in T cell-deficient (Tx + BM) and in sublethally irradiated mice, demonstrated that transfer of CHM-14 CTL clone, which secretes IFN-, was able to counteract M-MSV tumor growth despite the local mAb anti-IFN- treatment which may have prevented host cell recruitment. Moreover, repeated local rIFN- inoculations in Tx + BM mice did not counteract M-MSV tumor progression, thus confirming that other IFN- properties such as non-T cell recruitment, antiviral or anti-proliferative IFN- activities have little or no relevance when M-MSV-specific CTL are lacking. On the whole, these results indicate that in M-MSV-injected mice, tumor enhancement after mAb anti-IFN- treatment is principally caused by impaired differentiation of virus-specific CTL precursors.

  11. Viral genome RNA serves as messenger early in the infectious cycle of murine leukemia virus.

    PubMed Central

    Shurtz, R; Dolev, S; Aboud, M; Salzberg, S

    1979-01-01

    When NIH/3T3 mouse fibroblasts were infected with the Moloney strain of murine leukemia virus, part of the viral genome RNA molecules were detected in polyribosomes of the infected cells early in the infectious cycle. The binding appears to be specific, since we could demonstrate the release of viral RNA from polyribosomes with EDTA. Moreover, when infection occurred in the presence of cycloheximide, most viral RNA molecules were detected in the free cytoplasm. Size analysis on polyribosomal viral RNA molecules indicated that two size class molecules, 38S and 23S, are present in polyribosomes at 3 h after infection. Analysis of the polyriboadenylate [poly(rA)] content of viral RNA extracted from infected polyribosomes demonstrated that such molecules bind with greatest abundance at 3 h after infection, as has been detected with total viral RNA. No molecules lacking poly(rA) stretches could be detected in polyribosomes. Furthermore, when a similar analysis was performed on unbound molecules present in the free cytoplasm, identical results were obtained. We conclude that no selection towards poly(rA)-containing viral molecules is evident on binding to polyribosomes. These findings suggest that the incoming viral genome of the Moloney strain of murine leukemia virus may serve as a messenger for the synthesis of one or more virus-specific proteins early after infection of mouse fibroblasts. PMID:117118

  12. Phenotypes of murine leukemia virus-induced tumors: influence of 3' viral coding sequences.

    PubMed Central

    Ott, D E; Keller, J; Sill, K; Rein, A

    1992-01-01

    Murine leukemia viruses (MuLVs) induce leukemias and lymphomas in mice. We have used fluorescence-activated cell sorter analysis to determine the hematopoietic phenotypes of tumor cells induced by a number of MuLVs. Tumor cells induced by ecotropic Moloney, amphotropic 4070A, and 10A1 MuLVs and by two chimeric MuLVs, Mo(4070A) and Mo(10A1), were examined with antibodies to 13 lineage-specific cell surface markers found on myeloid cell, T-cell, and B-cell lineages. The chimeric Mo(4070A) and Mo(10A1) MuLVs, consisting of Moloney MuLV with the carboxy half of the Pol region and nearly all of the Env region of 4070A and 10A1, respectively, were constructed to examine the possible influence of these sequences on Moloney MuLV-induced tumor cell phenotypes. In some instances, these phenotypic analyses were supplemented by Southern blot analysis for lymphoid cell-specific genomic DNA rearrangements at the immunoglobulin heavy-chain, the T-cell receptor gamma, and the T-cell receptor beta loci. The results of our analysis showed that Moloney MuLV, 4070A, Mo(4070A), and Mo(10A1) induced mostly T-cell tumors. Moloney MuLV and Mo(4070A) induced a wide variety of T-cell phenotypes, ranging from immature to mature phenotypes, while 4070A induced mostly prothymocyte and double-negative (CD4- CD8-) T-cell tumors. The tumor phenotypes obtained with 10A1 and Mo(10A1) were each less variable than those obtained with the other MuLVs tested. 10A1 uniformly induced a tumor consisting of lineage marker-negative cells that lack lymphoid cell-specific DNA rearrangements and histologically appear to be early undifferentiated erythroid cell-like precursors. The Mo(10A1) chimera consistently induced an intermediate T-cell tumor. The chimeric constructions demonstrated that while 4070A 3' pol and env sequences apparently did not influence the observed tumor cell phenotypes, the 10A1 half of pol and env had a strong effect on the phenotypes induced by Mo(10A1) that resulted in a phenotypic

  13. Mechanisms of Graft-vs.-Leukemia against a Novel Murine Model of Chronic Myelogenous Leukemia

    DTIC Science & Technology

    2006-07-01

    AD_________________ Award Number: DAMD17-03-1-0311 TITLE: Mechanisms of Graft-vs.- Leukemia ...against a Novel Murine Model of Chronic Myelogenous Leukemia PRINCIPAL INVESTIGATOR: Warren D. Shlomchik, M.D. CONTRACTING ORGANIZATION...5a. CONTRACT NUMBER Mechanisms of Graft-vs.- Leukemia against a Novel Murine Model of Chronic Myelogenous Leukemia 5b. GRANT NUMBER DAMD17

  14. Effect of polymerase mutations on packaging of primer tRNAPro during murine leukemia virus assembly.

    PubMed Central

    Levin, J G; Seidman, J G

    1981-01-01

    The role of reverse transcriptase in selective encapsidation of the murine leukemia virus (MuLV) tRNA primer, tRNAPro, was investigated by examining the tRNA composition of several nonconditional pol mutants. One mutant, clone 23, which contains an altered polymerase about 40% smaller than the wild-type enzyme (B. I. Gerwin et al., J. Virol. 31:741-751, 1979) had a typical viral tRNA pattern, including normal levels of tRNAPro in free and 70S-associated 4S RNA. Another class of mutants, produced by Moloney murine leukemia virus-infected cell clone M13 and subclone M13/1, does not contain any detectable polymerase protein (A. Shields et al., Cell 14:601-609, 1978) and was found to have reduced amounts of tRNAPro in free 4S RNA. However, the level of tRNAPro associated with the genome was normal in the mutant virions. These results suggest that the reverse transcriptase protein is involved in the initial selection of tRNA primer during virus assembly, but not in the subsequent association of this tRNA with genomic RNA. Images PMID:6165833

  15. Feline leukemia virus integrase and capsid packaging functions do not change the insertion profile of standard Moloney retroviral vectors.

    PubMed

    Métais, J-Y; Topp, S; Doty, R T; Borate, B; Nguyen, A-D; Wolfsberg, T G; Abkowitz, J L; Dunbar, C E

    2010-06-01

    Adverse events linked to perturbations of cellular genes by vector insertion reported in gene therapy trials and animal models have prompted attempts to better understand the mechanisms directing viral vector integration. The integration profiles of vectors based on MLV, ASLV, SIV and HIV have all been shown to be non-random, and novel vectors with a safer integration pattern have been sought. Recently, we developed a producer cell line called CatPac that packages standard MoMLV vectors with feline leukemia virus (FeLV) gag, pol and env gene products. We now report the integration profile of this vector, asking if the FeLV integrase and capsid proteins could modify the MoMLV integration profile, potentially resulting in a less genotoxic pattern. We transduced rhesus macaque CD34+ hematopoietic progenitor cells with CatPac or standard MoMLV vectors, and determined their integration profile by LAM-PCR. We obtained 184 and 175 unique integration sites (ISs) respectively for CatPac and standard MoMLV vectors, and these were compared with 10 000 in silico-generated random IS. The integration profile for CatPac vector was similar to MoMLV and equally non-random, with a propensity for integration near transcription start sites and in highly dense gene regions. We found an IS for CatPac vector localized 715 nucleotides upstream of LMO-2, the gene involved in the acute lymphoblastic leukemia developed by X-SCID patients treated by gene therapy using MoMLV vectors. In conclusion, we found that replacement of MoMLV env, gag and pol gene products with FeLV did not alter the basic integration profile. Thus, there appears to be no safety advantage for this packaging system. However, considering the stability and efficacy of CatPac vectors, further development is warranted, using potentially safer vector backbones, for instance those with a SIN configuration.

  16. ESCRT Requirements for Murine Leukemia Virus Release.

    PubMed

    Bartusch, Christina; Prange, Reinhild

    2016-04-18

    The Murine Leukemia Virus (MLV) is a gammaretrovirus that hijack host components of the endosomal sorting complex required for transport (ESCRT) for budding. To determine the minimal requirements for ESCRT factors in MLV viral and viral-like particles (VLP) release, an siRNA knockdown screen of ESCRT(-associated) proteins was performed in MLV-producing human cells. We found that MLV VLPs and virions primarily engage the ESCRT-I factor Tsg101 and marginally the ESCRT-associated adaptors Nedd4-1 and Alix to enter the ESCRT pathway. Conversely, the inactivation of ESCRT-II had no impact on VLP and virion egress. By analyzing the effects of individual ESCRT-III knockdowns, VLP and virion release was profoundly inhibited in CHMP2A- and CHMP4B-knockdown cells. In contrast, neither the CHMP2B and CHMP4A isoforms nor CHMP3, CHMP5, and CHMP6 were found to be essential. In case of CHMP1, we unexpectedly observed that the CHMP1A isoform was specifically required for virus budding, but dispensable for VLP release. Hence, MLV utilizes only a subset of ESCRT factors, and viral and viral-like particles differ in ESCRT-III factor requirements.

  17. ESCRT Requirements for Murine Leukemia Virus Release

    PubMed Central

    Bartusch, Christina; Prange, Reinhild

    2016-01-01

    The Murine Leukemia Virus (MLV) is a gammaretrovirus that hijack host components of the endosomal sorting complex required for transport (ESCRT) for budding. To determine the minimal requirements for ESCRT factors in MLV viral and viral-like particles (VLP) release, an siRNA knockdown screen of ESCRT(-associated) proteins was performed in MLV-producing human cells. We found that MLV VLPs and virions primarily engage the ESCRT-I factor Tsg101 and marginally the ESCRT-associated adaptors Nedd4-1 and Alix to enter the ESCRT pathway. Conversely, the inactivation of ESCRT-II had no impact on VLP and virion egress. By analyzing the effects of individual ESCRT-III knockdowns, VLP and virion release was profoundly inhibited in CHMP2A- and CHMP4B-knockdown cells. In contrast, neither the CHMP2B and CHMP4A isoforms nor CHMP3, CHMP5, and CHMP6 were found to be essential. In case of CHMP1, we unexpectedly observed that the CHMP1A isoform was specifically required for virus budding, but dispensable for VLP release. Hence, MLV utilizes only a subset of ESCRT factors, and viral and viral-like particles differ in ESCRT-III factor requirements. PMID:27096867

  18. Solution Properties of Murine Leukemia Virus Gag Protein: Differences from HIV-1 Gag

    SciTech Connect

    Datta, Siddhartha A.K.; Zuo, Xiaobing; Clark, Patrick K.; Campbell, Stephen J.; Wang, Yun-Xing; Rein, Alan

    2012-05-09

    Immature retrovirus particles are assembled from the multidomain Gag protein. In these particles, the Gag proteins are arranged radially as elongated rods. We have previously characterized the properties of HIV-1 Gag in solution. In the absence of nucleic acid, HIV-1 Gag displays moderately weak interprotein interactions, existing in monomer-dimer equilibrium. Neutron scattering and hydrodynamic studies suggest that the protein is compact, and biochemical studies indicate that the two ends can approach close in three-dimensional space, implying the need for a significant conformational change during assembly. We now describe the properties of the Gag protein of Moloney murine leukemia virus (MLV), a gammaretrovirus. We found that this protein is very different from HIV-1 Gag: it has much weaker protein-protein interaction and is predominantly monomeric in solution. This has allowed us to study the protein by small-angle X-ray scattering and to build a low-resolution molecular envelope for the protein. We found that MLV Gag is extended in solution, with an axial ratio of {approx}7, comparable to its dimensions in immature particles. Mutational analysis suggests that runs of prolines in its matrix and p12 domains and the highly charged stretch at the C terminus of its capsid domain all contribute to this extended conformation. These differences between MLV Gag and HIV-1 Gag and their implications for retroviral assembly are discussed.

  19. Functional Characterization of the N Termini of Murine Leukemia Virus Envelope Proteins

    PubMed Central

    Lu, Chi-Wei; Roth, Monica J.

    2001-01-01

    The function of the N terminus of the murine leukemia virus (MuLV) surface (SU) protein was examined. A series of five chimeric envelope proteins (Env) were generated in which the N terminus of amphotropic 4070A was replaced by equivalent sequences from ecotropic Moloney MuLV (M-MuLV). Viral titers of these chimeras indicate that exchange with homologous sequences could be tolerated, up to V17eco/T15ampho (crossover III). Constructs encoding the first 28 amino acids (aa) of ecotropic M-MuLV resulted in Env expression and binding to the receptor; however, the virus titer was reduced 5- to 45-fold, indicating a postbinding block. Additional exchange beyond the first 28 aa of ecotropic MuLV Env resulted in defective protein expression. These N-terminal chimeras were also introduced into the AE4 chimeric Env backbone containing the amphotropic receptor binding domain joined at the hinge region to the ecotropic SU C terminus. In this backbone, introduction of the first 17 aa of the ecotropic Env protein significantly increased the titer compared to that of its parental chimera AE4, implying a functional coordination between the N terminus of SU and the C terminus of the SU and/or transmembrane proteins. These data functionally dissect the N-terminal sequence of the MuLV Env protein and identify differential effects on receptor-mediated entry. PMID:11287584

  20. Effects of murine leukemia viruses on the function of dendritic cells.

    PubMed

    Gabrilovich, D I; Roberts, M S; Harvey, J J; Botcherby, M; Bedford, P A; Knight, S C

    1993-11-01

    In asymptomatic human immunodeficiency virus-1 infection T cells respond normally to allogeneic dendritic cells (DC), but DC show reduced stimulatory capacity. By contrast in HTLV-1 infection no significant changes in allogeneic stimulation were seen but DC-stimulated activity of autologous T cells. In seeking animal models relevant to these diseases the effects of two murine leukemia retroviruses, Rauscher leukemia virus (RLV) and Moloney leukemia virus (MLV) on the function of dendritic cells and T cells in a primary mixed leucocyte reaction have been tested. Treatment by RLV in vitro suppressed the ability of DC to stimulate allogeneic T cells from healthy animals. MLV at the same concentration did not significantly affect the ability of DC to stimulate allogeneic T cells, but provoked considerable enhancement of the low level stimulation by DC in the syngeneic system. Similar results were obtained following in vivo exposure to viruses. Two pieces of evidence suggested that these effects were due to impairment of DC function and were not operating through infection of T cells. Firstly, exposure of T cells directly to virus in vitro and in vivo before stimulation with untreated allogeneic DC caused no significant alteration in T cell activity. Secondly, the impact of murine leukemia virus on DC function was not abrogated when infected DC were added to normal T cells and cultured in the presence of zidovudine. Treatment of DC by RLV caused a decrease of cluster formation with allogeneic T cells. No statistically significant influence of MLV was observed on cluster formation after 3-h of incubation in the allogeneic system. However, after 18-h incubation MLV-treated DC formed fewer clusters with T cells than untreated DC. At the same time a stimulatory effect of MLV on DC cluster formation with syngeneic T cells was found. Considerable decrease was found in major histocompatibility complex class II antigen and LFA-1 receptor expression on the DC surface in mice

  1. Characterization of producer cell-dependent restriction of murine leukemia virus replication.

    PubMed

    Serhan, Fatima; Jourdan, Nathalie; Saleun, Sylvie; Moullier, Philippe; Duisit, Ghislaine

    2002-07-01

    We previously reported that the human bronchocarcinoma cell line A549 produces poorly infectious gibbon ape leukemia virus-pseudotyped Moloney murine leukemia virus (MLV). In contrast, similar amounts of virions recovered from human fibrosarcoma HT1080 cells result in 10-fold-higher transduction rates (G. Duisit, A. Salvetti, P. Moullier, and F. Cosset, Hum. Gene Ther. 10:189-200, 1999). We have now extended this initial observation to other type-C envelope (Env) pseudotypes and analyzed the mechanism involved. Structural and morphological analysis showed that viral particles recovered from A549 (A549-MLV) and HT1080 (HT1080-MLV) cells were normal and indistinguishable from each other. They expressed equivalent levels of mature Env proteins and bound similarly to the target cells. Furthermore, incoming particles reached the cytosol and directed the synthesis of linear viral DNA equally efficiently. However, almost no detectable circular DNAs could be detected in A549-MLV-infected cells, indicating that the block of infection resulted from defective nuclear translocation of the preintegration complex. Interestingly, pseudotyping of A549-MLV with vesicular stomatitis virus glycoprotein G restored the amount of circular DNA forms as well as the transduction rates to HT1080-MLV levels, suggesting that the postentry blockage could be overcome by endocytic delivery of the core particles downstream of the restriction point. Thus, in contrast to the previously described target cell-dependent Fv-1 (or Fv1-like) restriction in mammalian cells (P. Pryciak and H. E. Varmus, J. Virol. 66:5959-5966, 1992; G. Towers, M. Bock, S. Martin, Y. Takeuchi, J. P. Stoye, and O. Danos, Proc. Natl. Acad. Sci. USA 97:12295-12299, 2000), we report here a new restriction of MLV replication that relies only on the producer cell type.

  2. LEUKEMIA-ASSOCIATED TRANSPLANTATION ANTIGENS RELATED TO MURINE LEUKEMIA VIRUS

    PubMed Central

    Sato, H.; Boyse, E. A.; Aoki, T.; Iritani, C.; Old, L. J.

    1973-01-01

    Two BALB radiation leukemias are strongly rejected by hybrids of BALB with certain other mouse strains, although BALB mice themselves exhibit no detectable resistance whatever. Hybrids immunized with progressively increased inocula are resistant to 200 x 106 or more leukemia cells; their serum is cytotoxic for the leukemia cells in vitro and protects BALB mice against challenge with these BALB leukemias. The antigenic system thus identified has been named X.1. In (BALB x B6) hybrids the major determinant of resistance was shown to be a B6 gene in the K region of H-2. This is likely to be the Rgv-1 (Resistance to gross virus) locus of Lilly, which may thus be identified in this case as an Ir (Immune response) allele conferring ability to respond to X.1 antigen on MuLV and leukemia cells, and so responsible for production of X.1 antibody and the rejection of X.1+ leukemia cells by hybrid mice. Immunoelectron microscopy with X.1 antiserum (from immunized hybrids) shows labeling both on the cell surface and on virions produced by the leukemia cells. It is not known whether X.1 comprises only one or more than one antigen. Three radiation-induced BALB leukemias, one A strain radiation-induced leukemia, and 15/15 AKR primary spontaneous leukemias were typed X.1+ by the cytotoxicity test. Several other leukemias, including one induced by passage A Gross virus and one long-transplanted AKR ascites leukemia carried in (B6 x AKR)F1 hybrids, were X.1-. Normal mice of strains with a high incidence of leukemia and one other strain (129) express X.1 antigen, but evidently in amounts too small for certain detection in vitro; by the method of absorption in vivo, however, these strains could be typed X.1+ and other strains X.1-. We ascribe the X.1 antigen system tentatively to a sub-type of MuLV that is not passage A Gross virus and is probably not the dominant sub-type in strains with a high incidence of leukemia. After repeated passage in hybrids, one of the BALB leukemias became

  3. Nucleotide Sequence of the Envelope Gene of Gardner-Arnstein Feline Leukemia Virus B Reveals Unique Sequence Homologies with a Murine Mink Cell Focus-Forming Virus †

    PubMed Central

    Elder, John H.; Mullins, James I.

    1983-01-01

    The nucleotide sequence of the envelope gene and the adjacent 3′ long terminal repeat (LTR) of Gardner-Arnstein feline leukemia virus of subgroup B (GA-FeLV-B) has been determined. Comparison of the derived amino acid sequence of the gp70-p15E polyprotein to those of several previously reported murine retroviruses revealed striking homologies between GA-FeLV-B gp70 and the gp70 of a Moloney virus-derived mink cell focus-forming virus. These homologies were located within the substituted (presumably xenotropic) portion of the mink cell focus-forming virus envelope gene and comprised amino acid sequences not present in three ecotropic virus gp70s. In addition, areas of insertions and deletions, in general, were the same between GA-FeLV-B and Moloney mink cell focus-forming virus, although the sizes of the insertions and deletions differed. Homologies between GA-FeLV-B and mink cell focus-forming virus gp70s is functionally significant in that they both possess expanded host ranges, a property dictated by gp70. The amino acid sequence of FeLV-B contains 12 Asn-X-Ser/Thr sequences, indicating 12 possible sites of N-linked glycosylation as compared with 7 or 8 for its murine counterparts. Comparison of the 3′ LTR of GA-FeLV-B to AKR and Moloney virus LTRs revealed extensive conservation in several regions including the “CCAAT” and Goldberg-Hogness (TATA) boxes thought to be involved in promotion of transcription and in the repeat region of the LTR. The inverted repeats that flanked the LTR of GA-FeLV-B were identical to the murine inverted repeats, but were one base longer than the latter. The region of U3 corresponding to the approximately 75-nucleotide “enhancer sequence” is present in GA-FeLV-B, but contains deletions relative to AKR and Moloney virus and is not repeated. An interesting pallindrome in the repeat region immediately 3′ to the U3 region was noted in all the LTRs, but was particularly pronounced in GA-FeLV-B. Possible roles for this

  4. Suppression of Moloney sarcoma virus immunity following sensitization with attenuated virus.

    PubMed

    Wood, G W

    1976-12-01

    Murine sarcoma virus (Moloney strain) (MSV-M)-induced tumors are unusual in that they regularly appear less than 2 weeks after virus inoculation, progress for 1 to 2 weeks, and are rejected by normal adult BALB/c mice. Rejectio leaves the animals immune to tumor induction. In the present study, presensitization of normal adult BALB/c mice with attenuated MSV-M resulted in an altered pattern of tumor immunity. Injection of active MSV-M into the presensitized animals resulted in tumor induction and rejection similar to that observed in normal animals, but rejection failed to produce protection against the secondary inoculation with MSV-M. After the second inoculation with active MSV-M, tumors appeared and progressed but ultimately were rejected. Over 80% of the mice died, 25% after the primary challenge and the remainder after the secondary challenge. At death, all mice had histological evidence of leukemia which was the probable cause of death. The animals that died following the secondary challenge also had evidence of disseminated MSV-M. Solid tumor nodules were found in skeletal muscle distant from the original site of inoculation, and active MSV-M was isolated from spleen and lungs. The possibility that the results were produced by specific suppression of MSV-Moloney leukemia virus immunity is discussed.

  5. Genetic rearrangements occurring during a single cycle of murine leukemia virus vector replication: characterization and implications.

    PubMed Central

    Parthasarathi, S; Varela-Echavarría, A; Ron, Y; Preston, B D; Dougherty, J P

    1995-01-01

    Retroviruses evolve at rapid rates, which is presumably advantageous for responding to selective pressures. Understanding the basic mutational processes involved during retroviral replication is important for comprehending the ability of retroviruses to escape immunosurveillance and antiviral drug treatment. Moreover, since retroviral vectors are important vehicles for somatic cell gene therapy, knowledge of the mechanism of retroviral variation is critical for anticipating untoward mutational events occurring during retrovirus-medicated gene transfer. The focus of this report is to examine the spectrum of genomic rearrangements arising during a single cycle of Moloney murine leukemia virus (MoMLV) vector virus replication. An MoMLV vector containing the herpes simplex virus thymidine kinase (tk) gene was constructed. MoMLV vector virus was produced in packaging lines, and target cells were infected. From a total of 224 mutant proviruses analyzed, 114 had gross rearrangements readily detectable by Southern blotting. The remaining proviruses were of parental size. PCR and DNA sequence analysis of 73 of the grossly rearranged mutant proviruses indicated they resulted from deletions, combined with insertions, duplications, and complex mutations that were a result of multiple genomic alterations in the same provirus. Complex hypermutations distinct from those previously described for spleen necrosis virus and human immunodeficiency virus were detected. There was a correlation between the mutation breakpoints and single-stranded regions in the predicted viral RNA secondary structure. The results also confirmed that the tk gene is inactivated at an average rate of about 8.8% per cycle of retroviral replication, which corresponds to a rate of mutation of 3%/kbp. PMID:7494312

  6. mRNA Molecules Containing Murine Leukemia Virus Packaging Signals Are Encapsidated as Dimers

    PubMed Central

    Hibbert, Catherine S.; Mirro, Jane; Rein, Alan

    2004-01-01

    Prior work by others has shown that insertion of ψ (i.e., leader) sequences from the Moloney murine leukemia virus (MLV) genome into the 3′ untranslated region of a nonviral mRNA leads to the specific encapsidation of this RNA in MLV particles. We now report that these RNAs are, like genomic RNAs, encapsidated as dimers. These dimers have the same thermostability as MLV genomic RNA dimers; like them, these dimers are more stable if isolated from mature virions than from immature virions. We characterized encapsidated mRNAs containing deletions or truncations of MLV ψ or with ψ sequences from MLV-related acute transforming viruses. The results indicate that the dimeric linkage in genomic RNA can be completely attributed to the ψ region of the genome. While this conclusion agrees with earlier electron microscopic studies on mature MLV dimers, it is the first evidence as to the site of the linkage in immature dimers for any retrovirus. Since the Ψ+ mRNA is not encapsidated as well as genomic RNA, it is only present in a minority of virions. The fact that it is nevertheless dimeric argues strongly that two of these molecules are packaged into particles together. We also found that the kissing loop is unnecessary for this coencapsidation or for the stability of mature dimers but makes a major contribution to the stability of immature dimers. Our results are consistent with the hypothesis that the packaging signal involves a dimeric structure in which the RNAs are joined by intermolecular interactions between GACG loops. PMID:15452213

  7. Ludwik Gross, Sarah Stewart, and the 1950s discoveries of Gross murine leukemia virus and polyoma virus.

    PubMed

    Morgan, Gregory J

    2014-12-01

    The Polish-American scientist Ludwik Gross made two important discoveries in the early 1950s. He showed that two viruses - murine leukemia virus and parotid tumor virus - could cause cancer when they were injected into susceptible animals. At first, Gross's discoveries were greeted with skepticism: it seemed implausible that viruses could cause a disease as complex as cancer. Inspired by Gross's initial experiments, similar results were obtained by Sarah Stewart and Bernice Eddy who later renamed the parotid tumor virus SE polyoma virus after finding it could cause many different types of tumors in mice, hamsters, and rats. Eventually the "SE" was dropped and virologists adopted the name "polyoma virus." After Gross's work was published, additional viruses capable of causing solid tumors or blood-borne tumors in mice were described by Arnold Graffi, Charlotte Friend, John Moloney and others. By 1961, sufficient data had been accumulated for Gross to confidently publish an extensive monograph--Oncogenic Viruses--the first history of tumor virology, which became a standard reference work and marked the emergence of tumor virology as a distinct, legitimate field of study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Supramolecular organization of immature and mature murine leukemia virus revealed by electron cryo-microscopy: Implications for retroviral assembly mechanisms

    PubMed Central

    Yeager, Mark; Wilson-Kubalek, Elizabeth M.; Weiner, Scott G.; Brown, Patrick O.; Rein, Alan

    1998-01-01

    We have used electron cryo-microscopy and image analysis to examine the native structure of immature, protease-deficient (PR−) and mature, wild-type (WT) Moloney murine leukemia virus (MuLV). Maturational cleavage of the Gag polyprotein by the viral protease is associated with striking morphological changes. The PR− MuLV particles exhibit a rounded central core, which has a characteristic track-like shell on its surface, whereas the WT MuLV cores display a polygonal surface with loss of the track-like feature. The pleomorphic shape and inability to refine unique orientation angles suggest that neither the PR− nor the WT MuLV adheres to strict icosahedral symmetry. Nevertheless, the PR− MuLV particles do exhibit paracrystalline order with a spacing between Gag molecules of ≈45 Å and a length of ≈200 Å. Because of the pleomorphic shape and paracrystalline packing of the Gag–RNA complexes, we raise the possibility that assembly of MuLV is driven by protein–RNA, as well as protein–protein, interactions. The maturation process involves a dramatic reorganization of the packing arrangements within the ribonucleoprotein core with disordering and loosening of the individual protein components. PMID:9636143

  9. Characterization of AKR murine leukemia virus sequences in AKR mouse substrains and structure of integrated recombinant genomes in tumor tissues.

    PubMed Central

    Quint, W; Quax, W; van der Putten, H; Berns, A

    1981-01-01

    A specific cDNA probe of AKR murine leukemia virus (AKR-MLV) was prepared to detect AKR-MLV sequences in normal and tumor tissues in a variety of AKR mouse substrains. AKR strains contained up to six endogenous AKR-MLV genomes. All substrains tested had one AKR-MLV locus in common, and closely related substrains had several proviruses integrated in an identical site. Virus-induced tumors in the AKR/FuRdA and AKR/JS strains showed a reintegration pattern of AKR-MLV sequences unique for the individual animal, suggesting a monoclonal origin for the outgrown tumors. An analysis of tumor DNAs from the AKR/FuRdA and AKR/JS substrains with restriction enzymes cleaving within the proviral genome revealed a new EcoRI restriction site and BamHI restriction site not present in normal tissues. The positions of these sites corresponded both with cleavage sites of EcoRI and BamHI in integrated Moloney recombinants and with the structure of isolated AKR mink cell focus-forming viruses. All tumors analyzed to data contain nearly identical integrated recombinant genomes, suggesting a causal relationship between the formation of recombinants and the leukemogenic process. Images PMID:6268802

  10. Xenotropic murine leukemia virus-related virus establishes an efficient spreading infection and exhibits enhanced transcriptional activity in prostate carcinoma cells.

    PubMed

    Rodriguez, Jason J; Goff, Stephen P

    2010-03-01

    Xenotropic murine leukemia virus-related virus (XMRV) is a novel human gammaretrovirus discovered in association with human prostate tumors. XMRV was first identified in prostate stromal cells surrounding the tumors of patients carrying a mutation in the HPC1 gene locus. To determine the tropism of XMRV in cell culture, we tested the ability of XMRV to spread and replicate in various prostate and nonprostate cell lines. We found that although the expression of XMRV viral proteins and the spread of infectious virus were minimal in a variety of cell lines, XMRV displayed robust expression and infection in LNCaP prostate tumor cells. The transcriptional activity of the XMRV long terminal repeat (LTR) was found to be higher than the Moloney murine leukemia virus LTRs in both LNCaP and WPMY-1 (simian virus 40-transformed prostate stromal cells). The U3 promoter of XMRV and a glucocorticoid response element (GRE) within the U3 were required for the transcriptional activity in LNCaP cells. Coexpression of the androgen receptor and stimulation with dihydrotestosterone stimulated XMRV-LTR-dependent transcription in 293T cells, and the GRE was required for this activity. These data suggest that XMRV may replicate more efficiently in LNCaP cells in part due to the transcriptional environment in LNCaP cells.

  11. An HSEF for murine myeloid leukemia

    SciTech Connect

    Bond, V.P.; Cronkite, E.P.; Bullis, J.E.; Wuu, C.S.; Marino, S.A.; Zaider, M.

    1996-10-01

    In the past decade, a large amount of effort has gone into the development of hit size effectiveness functions (HSEFs), with the ultimate aim of replacing the present absorbed dose-RBE-Q system. However, the absorbed dose determined at the tissue level is incapable of providing information on single hits on (doses to) the single cell. As a result, it is necessary to resort to microdosimetry, which is capable of providing not only the number of hits on cells, but the distribution of hit sizes as well. From this information, an HSEF can be derived. However, to date there have been no sets of data available on animals exposed to radiations of several qualities, and for which microdosimetric data were available. The objective of the present set of experiments was to remedy this situation. Large numbers of mice were exposed to radiations of several different qualities, and were observed throughout their entire lifespan for the appearance of myeloid leukemia. The HSEF developed for this neoplasm is presented and discussed.

  12. Epigenetic alterations in a murine model for chronic lymphocytic leukemia

    PubMed Central

    Chen, Shih-Shih; Sherman, Maura H; Hertlein, Erin; Johnson, Amy J; Teitell, Michael A.; Byrd, John C.; Plass, Christoph

    2010-01-01

    Early stages in the development of chronic lymphocytic leukemia (CLL) have not been explored mainly due to the inability to study normal B-cells in route to transformation. In order to determine such early events of leukemogenesis, we have used a well established mouse model for CLL. Over-expression of human TCL1, a known CLL oncogene, in murine B-cells leads to the development of mature CD19+/CD5+/IgM+ clonal leukemia with a similar disease phenotype seen in human CLL. Herein, we review our recent study using this TCL1 murine model for CLL and corresponding human CLL samples in a cross-species epigenomics approach to address the timing and relevance of epigenetic events occurring during leukemogenesis. We were able to demonstrate that the mouse model recapitulates epigenetic events very similar to what has been reported for human CLL and thus provides an exciting new tool to study early epigenetic events. Epigenetic alterations are seen at a time of three month after birth, much earlier than the phenotypically visible disease which occurs around 11 month of age. An early event in gene silencing is the inactivation of transcription factor Foxd3 expression through an NF-κB mediated process in animals with one month of age. PMID:19901553

  13. Substitution of Feline Leukemia Virus Long Terminal Repeat Sequences into Murine Leukemia Virus Alters the Pattern of Insertional Activation and Identifies New Common Insertion Sites

    PubMed Central

    Johnson, Chassidy; Lobelle-Rich, Patricia A.; Puetter, Adriane; Levy, Laura S.

    2005-01-01

    The recombinant retrovirus, MoFe2-MuLV (MoFe2), was constructed by replacing the U3 region of Moloney murine leukemia virus (M-MuLV) with homologous sequences from the FeLV-945 LTR. NIH/Swiss mice neonatally inoculated with MoFe2 developed T-cell lymphomas of immature thymocyte surface phenotype. MoFe2 integrated infrequently (0 to 9%) near common insertion sites (CISs) previously identified for either parent virus. Using three different strategies, CISs in MoFe2-induced tumors were identified at six loci, none of which had been previously reported as CISs in tumors induced by either parent virus in wild-type animals. Two of the newly identified CISs had not previously been implicated in lymphoma in any retrovirus model. One of these, designated 3-19, encodes the p101 regulatory subunit of phosphoinositide-3-kinase-gamma. The other, designated Rw1, is predicted to encode a protein that functions in the immune response to virus infection. Thus, substitution of FeLV-945 U3 sequences into the M-MuLV long terminal repeat (LTR) did not alter the target tissue for M-MuLV transformation but significantly altered the pattern of CIS utilization in the induction of T-cell lymphoma. These observations support a growing body of evidence that the distinctive sequence and/or structure of the retroviral LTR determines its pattern of insertional activation. The findings also demonstrate the oligoclonal nature of retrovirus-induced lymphomas by demonstrating proviral insertions at CISs in subdominant populations in the tumor mass. Finally, the findings demonstrate the utility of novel recombinant retroviruses such as MoFe2 to contribute new genes potentially relevant to the induction of lymphoid malignancy. PMID:15596801

  14. Dynein Regulators Are Important for Ecotropic Murine Leukemia Virus Infection

    PubMed Central

    Valle-Tenney, Roger; Opazo, Tatiana; Cancino, Jorge; Goff, Stephen P.

    2016-01-01

    ABSTRACT During the early steps of infection, retroviruses must direct the movement of the viral genome into the nucleus to complete their replication cycle. This process is mediated by cellular proteins that interact first with the reverse transcription complex and later with the preintegration complex (PIC), allowing it to reach and enter the nucleus. For simple retroviruses, such as murine leukemia virus (MLV), the identities of the cellular proteins involved in trafficking of the PIC in infection are unknown. To identify cellular proteins that interact with the MLV PIC, we developed a replication-competent MLV in which the integrase protein was tagged with a FLAG epitope. Using a combination of immunoprecipitation and mass spectrometry, we established that the microtubule motor dynein regulator DCTN2/p50/dynamitin interacts with the MLV preintegration complex early in infection, suggesting a direct interaction between the incoming viral particles and the dynein complex regulators. Further experiments showed that RNA interference (RNAi)-mediated silencing of either DCTN2/p50/dynamitin or another dynein regulator, NudEL, profoundly reduced the efficiency of infection by ecotropic, but not amphotropic, MLV reporters. We propose that the cytoplasmic dynein regulators are a critical component of the host machinery needed for infection by the retroviruses entering the cell via the ecotropic envelope pathway. IMPORTANCE Retroviruses must access the chromatin of host cells to integrate the viral DNA, but before this crucial event, they must reach the nucleus. The movement through the cytoplasm—a crowded environment where diffusion is slow—is thought to utilize retrograde transport along the microtubule network by the dynein complex. Different viruses use different components of this multisubunit complex. We found that the preintegration complex of murine leukemia virus (MLV) interacts with the dynein complex and that regulators of this complex are essential for

  15. Suppression of infectious murine leukemia virus in wild mice (Mus musculus) by passive immunization.

    PubMed

    Gardner, M B; Klement, V; Estes, J D; Gilden, R V; Toni, R; Huebner, R J

    1977-06-01

    Passive immunization with heterologous antivirus antiserum beginning at birth successfully suppressed infectious murine leukemia virus expression in Lake Casitas wild mice (Musmusculus) at 5-7 weeks of age.

  16. Epigenetic alterations in a murine model for chronic lymphocytic leukemia.

    PubMed

    Chen, Shih-Shih; Sherman, Mara H; Hertlein, Erin; Johnson, Amy J; Teitell, Michael A; Byrd, John C; Plass, Christoph

    2009-11-15

    Early stages in the development of chronic lymphocytic leukemia (CLL) have not been explored mainly due to the inability to study normal B-cells en route to transformation. In order to determine such early events of leukemogenesis, we have used a well established mouse model for CLL. Over-expression of human TCL1, a known CLL oncogene in murine B-cells leads to the development of mature CD19+/CD5+/IgM+ clonal leukemia with a disease phenotype similar to that seen in human CLL. Herein, we review our recent study using this TCL1-driven mouse model for CLL and corresponding human CLL samples in a cross-species epigenomics approach to address the timing and relevance of epigenetic events occurring during leukemogenesis. We demonstrated that the mouse model recapitulates the epigenetic events that have been reported for human CLL, affirming the power and validity of this mouse model to study early epigenetic events in cancer progression. Epigenetic alterations are detected as early as three months after birth, far before disease manifests at about 11 months of age. These mice undergo NFkappaB repressor complex mediated inactivation of the transcription factor Foxd3, whose targets become aberrantly methylated and silenced in mouse and human CLL. Overall, our data suggest the accumulated epigenetic alterations during CLL pathogenesis as a consequence of gene silencing through TCL1 and NFkappaB repressor complex, suggesting the relevance for NFkappaB as a therapeutic target in CLL.

  17. Selective Packaging of Host tRNA's by Murine Leukemia Virus Particles Does Not Require Genomic RNA

    PubMed Central

    Levin, Judith G.; Seidman, J. G.

    1979-01-01

    The 4S RNA contained in RNA tumor virus particles consists of a selected population of host tRNA's. However, the mechanism by which virions select host tRNA's has not been elucidated. We have considered a model which specifies that 35S genomic RNA determines which tRNA's are to be encapsidated as well as the relative amounts of these tRNA's within the virion. The model was tested by comparing the free 4S RNA composition of normal murine leukemia virus (MuLV) particles and noninfectious virions from actinomycin D (ActD)-treated cells, which are deficient in genomic RNA (ActD virions). Viral 4S RNA was analyzed by two-dimensional polyacrylamide gel electrophoresis. Surprisingly, the patterns obtained for control and ActD 4S RNA were identical to each other and were clearly distinct from the cell 4S RNA pattern. The viral patterns had three prominent areas of radioactivity. One of the spots was identified on the basis of its oligonucleotide fingerprint as tRNA Pro, the primer for MuLV RNA-directed DNA synthesis. These results were obtained with two different MuLV strains, AKR and Moloney, each grown in SC-1 cells. The demonstration that ActD virions contain primer tRNA and in general exhibit the characteristic MuLV tRNA pattern rather than the complete representation of cell 4S RNA leads to the conclusion that genomic RNA is not the major determinant in selective packaging of host tRNA's. A possible role for one or more viral proteins, including reverse transcriptase, is suggested. Images PMID:219227

  18. Exogenous IL-33 overcomes T cell tolerance in murine acute myeloid leukemia

    PubMed Central

    Qin, Lei; Dominguez, Donye; Chen, Siqi; Fan, Jie; Long, Alan; Zhang, Minghui; Fang, Deyu; Zhang, Yi; Kuzel, Timothy M.; Zhang, Bin

    2016-01-01

    Emerging studies suggest that dominant peripheral tolerance is a major mechanism of immune escape in disseminated leukemia. Using an established murine acute myeloid leukemia (AML) model, we here show that systemic administration of recombinant IL-33 dramatically inhibits the leukemia growth and prolongs the survival of leukemia-bearing mice in a CD8+ T cell dependent manner. Exogenous IL-33 treatment enhanced anti-leukemia activity by increasing the expansion and IFN-γ production of leukemia-reactive CD8+ T cells. Moreover, IL-33 promoted dendritic cell (DC) maturation and activation in favor of its cross presentation ability to evoke a vigorous anti-leukemia immune response. Finally, we found that the combination of PD-1 blockade with IL-33 further prolonged the survival, with half of the mice achieving complete regression. Our data establish a role of exogenous IL-33 in reversing T cell tolerance, and suggest its potential clinical implication into leukemia immunotherapy. PMID:27517629

  19. Antileukemic Efficacy of Continuous vs Discontinuous Dexamethasone in Murine Models of Acute Lymphoblastic Leukemia

    PubMed Central

    Ramsey, Laura B.; Janke, Laura J.; Payton, Monique A.; Cai, Xiangjun; Paugh, Steven W.; Karol, Seth E.; Kamdem, Landry Kamdem; Cheng, Cheng; Williams, Richard T.; Jeha, Sima; Pui, Ching-Hon; Evans, William E.; Relling, Mary V.

    2015-01-01

    Osteonecrosis is one of the most common, serious, toxicities resulting from the treatment of acute lymphoblastic leukemia. In recent years, pediatric acute lymphoblastic leukemia clinical trials have used discontinuous rather than continuous dosing of dexamethasone in an effort to reduce the incidence of osteonecrosis. However, it is not known whether discontinuous dosing would compromise antileukemic efficacy of glucocorticoids. Therefore, we tested the efficacy of discontinuous dexamethasone against continuous dexamethasone in murine models bearing human acute lymphoblastic leukemia xenografts (n = 8 patient samples) or murine BCR-ABL+ acute lymphoblastic leukemia. Plasma dexamethasone concentrations (7.9 to 212 nM) were similar to those achieved in children with acute lymphoblastic leukemia using conventional dosages. The median leukemia-free survival ranged from 16 to 59 days; dexamethasone prolonged survival from a median of 4 to 129 days in all seven dexamethasone-sensitive acute lymphoblastic leukemias. In the majority of cases (7 of 8 xenografts and the murine BCR-ABL model) we demonstrated equal efficacy of the two dexamethasone dosing regimens; whereas for one acute lymphoblastic leukemia sample, the discontinuous regimen yielded inferior antileukemic efficacy (log-rank p = 0.002). Our results support the clinical practice of using discontinuous rather than continuous dexamethasone dosing in patients with acute lymphoblastic leukemia. PMID:26252865

  20. Antileukemic Efficacy of Continuous vs Discontinuous Dexamethasone in Murine Models of Acute Lymphoblastic Leukemia.

    PubMed

    Ramsey, Laura B; Janke, Laura J; Payton, Monique A; Cai, Xiangjun; Paugh, Steven W; Karol, Seth E; Kamdem Kamdem, Landry; Cheng, Cheng; Williams, Richard T; Jeha, Sima; Pui, Ching-Hon; Evans, William E; Relling, Mary V

    2015-01-01

    Osteonecrosis is one of the most common, serious, toxicities resulting from the treatment of acute lymphoblastic leukemia. In recent years, pediatric acute lymphoblastic leukemia clinical trials have used discontinuous rather than continuous dosing of dexamethasone in an effort to reduce the incidence of osteonecrosis. However, it is not known whether discontinuous dosing would compromise antileukemic efficacy of glucocorticoids. Therefore, we tested the efficacy of discontinuous dexamethasone against continuous dexamethasone in murine models bearing human acute lymphoblastic leukemia xenografts (n = 8 patient samples) or murine BCR-ABL+ acute lymphoblastic leukemia. Plasma dexamethasone concentrations (7.9 to 212 nM) were similar to those achieved in children with acute lymphoblastic leukemia using conventional dosages. The median leukemia-free survival ranged from 16 to 59 days; dexamethasone prolonged survival from a median of 4 to 129 days in all seven dexamethasone-sensitive acute lymphoblastic leukemias. In the majority of cases (7 of 8 xenografts and the murine BCR-ABL model) we demonstrated equal efficacy of the two dexamethasone dosing regimens; whereas for one acute lymphoblastic leukemia sample, the discontinuous regimen yielded inferior antileukemic efficacy (log-rank p = 0.002). Our results support the clinical practice of using discontinuous rather than continuous dexamethasone dosing in patients with acute lymphoblastic leukemia.

  1. The target cell of transformation is distinct from the leukemia stem cell in murine CALM/AF10 leukemia models.

    PubMed

    Dutta, S; Krause, A; Vosberg, S; Herold, T; Ksienzyk, B; Quintanilla-Martinez, L; Tizazu, B; Chopra, M; Graf, A; Krebs, S; Blum, H; Greif, P A; Vetter, A; Metzeler, K; Rothenberg-Thurley, M; Schneider, M R; Dahlhoff, M; Spiekermann, K; Zimber-Strobl, U; Wolf, E; Bohlander, S K

    2016-05-01

    The CALM/AF10 fusion gene is found in various hematological malignancies including acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia and malignant lymphoma. We have previously identified the leukemia stem cell (LSC) in a CALM/AF10-driven murine bone marrow transplant AML model as B220+ lymphoid cells with B-cell characteristics. To identify the target cell for leukemic transformation or 'cell of origin of leukemia' (COL) in non-disturbed steady-state hematopoiesis, we inserted the CALM/AF10 fusion gene preceded by a loxP-flanked transcriptional stop cassette into the Rosa26 locus. Vav-Cre-induced panhematopoietic expression of the CALM/AF10 fusion gene led to acute leukemia with a median latency of 12 months. Mice expressing CALM/AF10 in the B-lymphoid compartment using Mb1-Cre or CD19-Cre inducer lines did not develop leukemia. Leukemias had a predominantly myeloid phenotype but showed coexpression of the B-cell marker B220, and had clonal B-cell receptor rearrangements. Using whole-exome sequencing, we identified an average of two to three additional mutations per leukemia, including activating mutations in known oncogenes such as FLT3 and PTPN11. Our results show that the COL for CALM/AF10 leukemia is a stem or early progenitor cell and not a cell of B-cell lineage with a phenotype similar to that of the LSC in CALM/AF10+ leukemia.

  2. Amphotropic murine leukemia viruses induce spongiform encephalomyelopathy

    PubMed Central

    Münk, Carsten; Löhler, Jürgen; Prassolov, Vladimir; Just, Ursula; Stockschläder, Marcus; Stocking, Carol

    1997-01-01

    Recombinants of amphotropic murine leukemia virus (A-MuLV) have found widespread use in retroviral vector systems due to their ability to efficiently and stably infect cells of several different species, including human. Previous work has shown that replication-competent recombinants containing the amphotropic env gene, encoding the major SU envelope glycoprotein that determines host tropism, induce lymphomas in vivo. We show here that these viruses also induce a spongiform encephalomyelopathy in mice inoculated perinatally. This fatal central nervous system disease is characterized by noninflammatory spongiform lesions of nerve and glial cells and their processes, and is associated with moderate astro- and microgliosis. The first clinical symptoms are ataxia, tremor, and spasticity, progressing to complete tetraparesis and incontinence, and finally death of the animal. Sequences within the amphotropic env gene are necessary for disease induction. Coinfection of A-MuLV recombinants with nonneuropathogenic ecotropic or polytropic MuLV drastically increases the incidence, degree, and distribution of the neurodegenerative disorder. The consequence of these results in view of the use of A-MuLV recombinants in the clinic is discussed. PMID:9159161

  3. Abelson murine leukemia virus: structural requirements for transforming gene function.

    PubMed Central

    Srinivasan, A; Dunn, C Y; Yuasa, Y; Devare, S G; Reddy, E P; Aaronson, S A

    1982-01-01

    The integrated Abelson murine leukemia virus (A-MuLV) genome cloned in bacteriophage lambda gtWES.lambda B was used to localize viral genetic sequences required for transformation. Comparison of the biological activity of cloned A-MuLV genomic and subgenomic fragments showed that subgenomic clones that lacked the 5' long terminal repeat and adjoining sequences (300 base pairs downstream of the repeat) were not biologically active. In contrast, subgenomic clones that lacked the 3' long terminal repeat and as much as 1.3 kilobase pairs of the A-MuLV cell-derived abl gene were as efficient as wild-type viral DNA in transformation. The A-MuLV-encoded polyprotein P120 and its associated protein kinase activity were detected in transformants obtained by transfection with Cla I, BamHI, and HindIII subgenomic clones. In contrast, individual transformants obtained with subgenomic Sal I clones expressed A-MuLV proteins ranging in size from 82,000 to 95,000 daltons. Each demonstrated an associated protein kinase activity. These results provide direct genetic evidence that only the proximal 40% of abl with its associated 5' helper viral sequences is required for fibroblast transformation. Images PMID:6291048

  4. Human APOBEC3G incorporation into murine leukemia virus particles

    SciTech Connect

    Kremer, Melanie; Schnierle, Barbara S. . E-mail: schba@pei.de

    2005-06-20

    The human APOBEC3G protein exhibits broad antiretroviral activity against a variety of retroviruses. It is packaged into viral particles and executes its antiviral function in the target cell. The packaging of APOBEC3G into different viral particles requires a mechanism that confers this promiscuity. Here, APOBEC3G incorporation into murine leukemia virus (MLV) was studied using retroviral vectors. APOBEC3G uptake did not require either its cytidine deaminase activity or the presence of a retroviral vector genome. Results from immunoprecipitation and co-localization studies of APOBEC3G with a MLV Gag-CFP (cyan fluorescent protein) fusion protein imply an interaction between both proteins. RNase A treatment did not inhibit the co-precipitation of Gag-CFP and APOBEC3G, suggesting that the interaction is RNA independent. Like human immunodeficiency virus (HIV) Gag, the MLV Gag precursor protein appears to interact with APOBEC3G, indicating that Gag contains conserved structures which are used to encapsidate APOBEC3G into different retroviral particles.

  5. Gene profiling of Graffi murine leukemia virus-induced lymphoid leukemias: identification of leukemia markers and Fmn2 as a potential oncogene.

    PubMed

    Charfi, Cyndia; Voisin, Véronique; Levros, Louis-Charles; Edouard, Elsy; Rassart, Eric

    2011-02-10

    The Graffi murine leukemia virus induces a large spectrum of leukemias in mice and thus provides a good model to compare the transcriptome of all types of leukemias. We analyzed the gene expression profiles of both T and B leukemias induced by the virus with DNA microarrays. Given that we considered that a 4-fold change in expression level was significant, 388 probe sets were associated to B, to T, or common to both leukemias. Several of them were not yet associated with lymphoid leukemia. We confirmed specific deregulation of Fmn2, Arntl2, Bfsp2, Gfra2, Gpm6a, and Gpm6b in B leukemia, of Nln, Fbln1, and Bmp7 in T leukemias, and of Etv5 in both leukemias. More importantly, we show that the mouse Fmn2 induced an anchorage-independent growth, a drastic modification in cell shape with a concomitant disruption of the actin cytoskeleton. Interestingly, we found that human FMN2 is overexpressed in approximately 95% of pre-B acute lymphoblastic leukemia with the highest expression levels in patients with a TEL/AML1 rearrangement. These results, surely related to the role of FMN2 in meiotic spindle maintenance, suggest its important role in leukemogenesis. Finally, we propose a new panel of genes potentially involved in T and/or B leukemias.

  6. Characterization of pal-1, a common proviral insertion site in murine leukemia virus-induced lymphomas of c-myc and Pim-1 transgenic mice.

    PubMed Central

    Scheijen, B; Jonkers, J; Acton, D; Berns, A

    1997-01-01

    Insertional mutagenesis with Moloney murine leukemia virus (MoMLV) in c-myc and Pim-1 transgenic mice permits the identification of oncogenes that collaborate with the transgenes in lymphomagenesis. The recently identified common insertion site pal-1, in MoMLV-induced lymphomas, is located in a region in which several independent integration clusters are found: eis-1, gfi-1, and evi-5. Proviral insertions of MoMLV in the different integration clusters upregulate the transcriptional activity of the Gfi-1 gene, which is located within the pal-1 locus. The eis-1/pal-1/gfi-1/evi-5 locus serves as a target for MoMLV proviral insertions in pre-B-cell lymphomas of Emu-myc transgenic mice (20%) and in T-cell lymphomas of H-2K-myc (75%) and Emu-pim-1 (93%) transgenic mice. Many tumors overexpress both Gfi-1 as well as Myc and Pim gene family members, indicating that Gfi-1 collaborates with Myc and Pim in lymphomagenesis. Proviral integrations in the previously identified insertion site bmi-1 are, however, mutually exclusive with integrations in the eis-1/pal-1/gfi-1/evi-5 locus. This finding suggests that Bmi-1 and Gfi-1 belong to the same complementation group in lymphoid transformation. PMID:8985317

  7. Overview of the Use of Murine Models in Leukemia and Lymphoma Research

    PubMed Central

    Kohnken, Rebecca; Porcu, Pierluigi; Mishra, Anjali

    2017-01-01

    Murine models have been adopted as a significant and powerful tool in the study of cancer. The applications of murine models of cancer are numerous: mechanism discovery, oncogenesis, molecular genetics, microenvironment, metastasis, and therapeutic efficacy. Leukemias and lymphomas are a group of highly heterogeneous hematologic malignancies that affect people of all ages and ethnicities. Leukemia and lymphoma arise from hematopoietic and immune cells and usually spread widely throughout the body. The liquid nature of many of these malignancies, as well as the complex microenvironment from which they arise and their multifaceted genetic basis, has added to the difficulty in generating appropriate and translational models to study them. Murine models of leukemia and lymphoma have made substantial contributions to our understanding of the pathobiology of these disorders in humans. However, while there are many advantages to these models, limitations remain. In this review, we discuss the mouse as a model to study leukemia and lymphoma, and the importance of choosing the correct methodology. Specific examples of murine models of leukemias and lymphomas are provided, with particular attention to those that are highly translational to their human counterpart. Finally, future applications of murine models and potential for better models are discussed. PMID:28265553

  8. A Multicenter Blinded Analysis Indicates No Association between Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and either Xenotropic Murine Leukemia Virus-Related Virus or Polytropic Murine Leukemia Virus

    PubMed Central

    Alter, Harvey J.; Mikovits, Judy A.; Switzer, William M.; Ruscetti, Francis W.; Lo, Shyh-Ching; Klimas, Nancy; Komaroff, Anthony L.; Montoya, Jose G.; Bateman, Lucinda; Levine, Susan; Peterson, Daniel; Levin, Bruce; Hanson, Maureen R.; Genfi, Afia; Bhat, Meera; Zheng, HaoQiang; Wang, Richard; Li, Bingjie; Hung, Guo-Chiuan; Lee, Li Ling; Sameroff, Stephen; Heneine, Walid; Coffin, John; Hornig, Mady; Lipkin, W. Ian

    2012-01-01

    ABSTRACT The disabling disorder known as chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) has been linked in two independent studies to infection with xenotropic murine leukemia virus-related virus (XMRV) and polytropic murine leukemia virus (pMLV). Although the associations were not confirmed in subsequent studies by other investigators, patients continue to question the consensus of the scientific community in rejecting the validity of the association. Here we report blinded analysis of peripheral blood from a rigorously characterized, geographically diverse population of 147 patients with CFS/ME and 146 healthy subjects by the investigators describing the original association. This analysis reveals no evidence of either XMRV or pMLV infection. PMID:22991430

  9. SUPPRESSION OF MURINE LEUKEMIAS BY L-ASPARAGINASE

    PubMed Central

    Boyse, Edward A.; Old, Lloyd J.; Campbell, H. A.; Mashburn, Louise T.

    1967-01-01

    A survey of 109 recently derived leukemias of the mouse revealed that sensitivity to suppression by guinea pig serum is a common property of transplanted leukemias of certain classes. The sensitive leukemias included five that arose spontaneously in mice of strains with a low incidence of leukemia and 21 that were induced by X-radiation. Two GPS-sensitive leukemias were not more sensitive than a GPS-resistant leukemia to a range of standard chemotherapeutic agents. The effectiveness of L-asparaginase EC-2 from Escherichia coli in suppression of the GPS-sensitive leukemia EARAD1 depends upon the conditions of assay. Whereas it is not inhibitory when administered as a single dose at the time of inoculation of the leukemia it is considerably more effective than GPS when used in the treatment of established leukemia. Permanent cures of 7-day generalized transplants of EARAD1 can be effected by the administration of 2000 or more units of EC-2. Immunological factors apparently do not contribute to cure as treated survivors are fully susceptible to rechallenge with minimal numbers of cells from the same leukemia. Reinoculated survivors with progressively growing transplants have been successfully retreated with EC-2. The blood clearance of EC-2 L-asparaginase injected into mice is much more rapid than that of GPS L-asparaginase. After intraperitoneal inoculation of the EC-1 L-asparaginase, which does not have leukemia-inhibitory activity, only very low levels of enzyme activity could be detected in the serum. The effectiveness of EC-2 from E. coli and its availability from a virtually limitless source will make it possible to extend the study of inhibition of leukemias and other tumors by L-asparaginase to species other than small rodents. PMID:5334543

  10. [Establishment of the retrovirus-mediated murine model with MLL-AF9 leukemia].

    PubMed

    Xu, Si-Miao; Yang, Yang; Zhou, Mi; Zhao, Xue-Jiao; Qin, Yu; Zhang, Pei-Ling; Yuan, Rui-Feng; Zhou, Jian-Feng; Fang, Yong

    2013-10-01

    This study was purposed to establish a retrovirus-mediated murine model with MLL-AF9 leukemia, so as to provide a basis for further investigation of the pathogenesis and therapeutic strategy of MLL associated leukemia. Murine (CD45.2) primary hematopoietic precursor positively selected for expression of the progenitor marker c-Kit by means of MACS were transduced with a retrovirus carrying MLL-AF9 fusion gene. After cultured in vitro, the transduced cells were injected intravenously through the tail vein into the lethally irradiated mice (CD45.1). PCR, flow cytometry and morphological observation were employed to evaluate the murine leukemia model system. The results showed that MLL-AF9 fusion gene was expressed in the infected cells, and the cells had a dramatically enhanced potential to generate myeloid colonies with primitive and immature morphology. Flow cytometric analysis revealed that the immortalized cells highly expressed myeloid lineage surface markers Gr-1 and Mac-1. Moreover, the expression levels of Hoxa9 and Meis1 mRNA were significantly higher in the MLL-AF9 cells than that in control. The mice transplanted with MLL-AF9 cells displayed typical signs of leukemia within 6-12 weeks. Extensive infiltration leukemic cells was observed in the Wright-Giemsa stained peripheral blood smear and bone marrow, and also in the histology of liver and spleen. Flow cytometric analysis of the bone marrow and spleen cells demonstrated that the CD45.2 populations expressed highly myeloid markers Gr-1 and Mac-1. The leukemic mice died within 12 weeks. It is concluded that the retrovirus-mediated murine model with MLL-AF9 leukemia is successfully established, which can be applied in the subsequent researches.

  11. Anti-CD45 radioimmunotherapy using 211At with bone marrow transplantation prolongs survival in a disseminated murine leukemia model

    SciTech Connect

    Orozco, Johnnie J.; Back, Tom; Kenoyer, Aimee L.; Balkin, Ethan R.; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.; Frayo, Shani; Hylarides, Mark; Green, Damian J.; Gopal, Ajay K.; Press, Oliver W.; Pagel, John M.

    2013-05-15

    Anti-CD45 Radioimmunotherapy using an Alpha-Emitting Radionuclide 211At Combined with Bone Marrow Transplantation Prolongs Survival in a Disseminated Murine Leukemia Model ABSTRACT Despite aggressive chemotherapy combined with hematopoietic cell transplant (HCT), many patients with acute myeloid leukemia (AML) relapse. Radioimmunotherapy (RIT) using antibodies (Ab) labeled primarily with beta-emitting radionuclides has been explored to reduce relapse.

  12. Radiation-induced myeloid leukemia in murine models

    PubMed Central

    2014-01-01

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included. PMID:25062865

  13. Radiation-induced myeloid leukemia in murine models.

    PubMed

    Rivina, Leena; Davoren, Michael; Schiestl, Robert H

    2014-07-25

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included.

  14. Biochemical analysis of murine leukemia viruses isolated from radiation-induced leukemias of strain BALB/c

    SciTech Connect

    Ellis, R.W.; Hopkins, N.; Fleissner, E.

    1980-02-01

    Murine leukemia viruses isolated from radiation-induced BALB/c leukemias were characterized with respect to viral proteins and RNA. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the viral structural proteins revealed that for p12, p15, p30, and gp70, three to four electrophoretic variants of each could be detected. There was no correlation found between any of these mobilities and N- or B-tropism of the viruses. Proteins of all xenotropic viral isolates were identical in their gel electrophoretic profiles. The similar phenotypes of multiple viral clones from individual leukemias and of isolates grown in different cells suggest that the polymorphism of ecotropic viruses was generated in vivo rather than during in vitro virus growth. By two-dimensional fingerprinting of RNase T1-resistant oligonucleotides from 70S viral RNA, the previously reported association of N- and B-tropism with two distinct oligonucleotides was confirmed. The presence of two other oligonucleotides was correlated with positive and negative phenotypes of the virus-coded G/sub IX/ cell surface antigen. The RNAs of two B-tropic isolates with distinctive p15 and p12 phenotypes differed from the RNA of a prototype N-tropic virus by the absence of three oligonucleotides mapping in the 5' portion (gag region) of the prototype RNA. In addition, one small-plaque B-tropic virus displayed extensive changes in the RNA sequences associated with the env region of the prototype.

  15. Modulatory Effects and Action Mechanisms of Tryptanthrin on Murine Myeloid Leukemia Cells

    PubMed Central

    Chan, Hoi-Ling; Yip, Hon-Yan; Mak, Nai-Ki; Leung, Kwok-Nam

    2009-01-01

    Leukemia is the disorder of hematopoietic cell development and is characterized by an uncoupling of cell proliferation and differentiation. There is a pressing need for the development of novel tactics for leukemia therapy as conventional treatments often have severe adverse side effects. Tryptanthrin (6,12-dihydro-6,12-dioxoindolo-(2,1-b)-quinazoline) is a naturally-occurring, weakly basic alkaloid isolated from the dried roots of medicinal indigo plants (Ban-Lan-Gen). It has been reported to have various biological and pharmacological activities, including anti-microbial, anti-inflammatory, immunomodulatory and anti-tumor effects. However, its modulatory effects and action mechanisms on myeloid cells remain poorly understood. In this study, tryptanthrin was shown to suppress the proliferation of the murine myeloid leukemia WEHI-3B JCS cells in a dose- and time-dependent manner. It also significantly reduced the growth of WEHI-3B JCS cells in vivo in syngeneic BALB/c mice. However, it exhibited no significant direct cytotoxicity on normal murine peritoneal macrophages. Flow cytometric analysis showed an obvious cell cycle arrest of the tryptanthrin-treated WEHI-3B JCS cells at the G0/G1 phase. The expression of cyclin D2, D3, Cdk 2, 4 and 6 genes in WEHI-3B JCS cells was found to be down-regulated at 24 h as measured by RT-PCR. Morphological and functional studies revealed that tryptanthrin could induce differentiation in WEHI-3B JCS cells, as shown by the increases in vacuolation, cellular granularity and NBT-reducing activity in tryptanthrin-treated cells. Collectively, our findings suggest that tryptanthrin might exert its anti-tumor effect on the murine myelomonocytic leukemia WEHI-3B JCS cells by causing cell cycle arrest and by triggering cell differentiation. PMID:19887046

  16. Flt3 does not play a critical role in murine myeloid leukemias induced by MLL fusion genes.

    PubMed

    Albouhair, Stéphanie; Morgado, Ester; Lavau, Catherine

    2013-01-01

    Leukemias harboring MLL translocations are frequent in children and adults, and respond poorly to therapies. The receptor tyrosine kinase FLT3 is highly expressed in these leukemias. In vitro studies have shown that pediatric MLL-rearranged ALL cells are sensitive to FLT3 inhibitors and clinical trials are ongoing to measure their therapeutic efficacy. We sought to determine the contribution of Flt3 in the pathogenesis of MLL-rearranged leukemias using a myeloid leukemia mouse model. Bone marrow from Flt3 null mice transduced with MLL-ENL or MLL-CBP was transplanted into host mice and Flt3 (-/-) leukemias were compared to their Flt3 wild type counterparts. Flt3 deficiency did not delay disease onset and had minimal impact on leukemia characteristics. To determine the anti-leukemic effect of FLT3 inhibition we studied the sensitivity of MLL-ENL leukemia cells to the FLT3 inhibitor PKC412 ex vivo. As previously reported for human MLL-rearranged leukemias, murine MLL-ENL leukemia cells with higher Flt3 levels were more sensitive to the cytotoxicity of PKC412. Interestingly, Flt3 deficient leukemia samples also displayed some sensitivity to PKC412. Our findings demonstrate that myeloid leukemias induced by MLL-rearranged genes are not dependent upon Flt3 signaling. They also highlight the discrepancy between the sensitivity of cells to Flt3 inhibition in vitro and the lack of contribution of Flt3 to the pathogenesis of MLL-rearranged leukemias in vivo.

  17. Interactions of Host Proteins with the Murine Leukemia Virus Integrase

    PubMed Central

    Studamire, Barbara; Goff, Stephen P.

    2010-01-01

    Retroviral infections cause a variety of cancers in animals and a number of diverse diseases in humans such as leukemia and acquired immune deficiency syndrome. Productive and efficient proviral integration is critical for retroviral function and is the key step in establishing a stable and productive infection, as well as the mechanism by which host genes are activated in leukemogenesis. Host factors are widely anticipated to be involved in all stages of the retroviral life cycle, and the identification of integrase interacting factors has the potential to increase our understanding of mechanisms by which the incoming virus might appropriate cellular proteins to target and capture host DNA sequences. Identification of MoMLV integrase interacting host factors may be key to designing efficient and benign retroviral-based gene therapy vectors; key to understanding the basic mechanism of integration; and key in designing efficient integrase inhibitors. In this review, we discuss current progress in the field of MoMLV integrase interacting proteins and possible roles for these proteins in integration. PMID:21637732

  18. Inoculation of newborn SWR/J females with an ecotropic murine leukemia virus can produce transgenic mice.

    PubMed

    Panthier, J J; Condamine, H; Jacob, F

    1988-02-01

    Endogenous ecotropic murine leukemia proviruses that were not present in the parental stock are acquired by the progeny of some SWR/J X RF/J hybrid females. We have made a stock of an ecotropic murine leukemia virus produced by such a hybrid female and inoculated newborn SWR/J females with it. We show that upon crossing of the inoculated females to SWR/J males, some of their progeny acquire ecotropic proviruses. Although most of these proviruses appear to be distributed in somatic tissues in a mosaic way, some are transmitted through the germ line. Thus an exogenous infection is able to mimic the phenomenon observed in SWR/J X RF/J hybrid mice. Available evidence suggests that this infection occurs during oogenesis in the recipient female. Our results document the conversion of an exogenous infectious ecotropic murine leukemia virus to an endogenous provirus without any manipulation of either eggs or embryos.

  19. Murine leukemia virus uses NXF1 for nuclear export of spliced and unspliced viral transcripts.

    PubMed

    Sakuma, Toshie; Davila, Jaime I; Malcolm, Jessica A; Kocher, Jean-Pierre A; Tonne, Jason M; Ikeda, Yasuhiro

    2014-04-01

    Intron-containing mRNAs are subject to restricted nuclear export in higher eukaryotes. Retroviral replication requires the nucleocytoplasmic transport of both spliced and unspliced RNA transcripts, and RNA export mechanisms of gammaretroviruses are poorly characterized. Here, we report the involvement of the nuclear export receptor NXF1/TAP in the nuclear export of gammaretroviral RNA transcripts. We identified a conserved cis-acting element in the pol gene of gammaretroviruses, including murine leukemia virus (MLV) and xenotropic murine leukemia virus (XMRV), named the CAE (cytoplasmic accumulation element). The CAE enhanced the cytoplasmic accumulation of viral RNA transcripts and the expression of viral proteins without significantly affecting the stability, splicing, or translation efficiency of the transcripts. Insertion of the CAE sequence also facilitated Rev-independent HIV Gag expression. We found that the CAE sequence interacted with NXF1, whereas disruption of NXF1 ablated CAE function. Thus, the CAE sequence mediates the cytoplasmic accumulation of gammaretroviral transcripts in an NXF1-dependent manner. Disruption of NXF1 expression impaired cytoplasmic accumulations of both spliced and unspliced RNA transcripts of XMRV and MLV, resulting in their nuclear retention or degradation. Thus, our results demonstrate that gammaretroviruses use NXF1 for the cytoplasmic accumulation of both spliced and nonspliced viral RNA transcripts. Murine leukemia virus (MLV) has been studied as one of the classic models of retrovirology. Although unspliced host messenger RNAs are rarely exported from the nucleus, MLV actively exports unspliced viral RNAs to the cytoplasm. Despite extensive studies, how MLV achieves this difficult task has remained a mystery. Here, we have studied the RNA export mechanism of MLV and found that (i) the genome contains a sequence which supports the efficient nuclear export of viral RNAs, (ii) the cellular factor NXF1 is involved in the

  20. Targeting of a Nuclease to Murine Leukemia Virus Capsids Inhibits Viral Multiplication

    NASA Astrophysics Data System (ADS)

    Natsoulis, Georges; Seshaiah, Partha; Federspiel, Mark J.; Rein, Alan; Hughes, Stephen H.; Boeke, Jef D.

    1995-01-01

    Capsid-targeted viral inactivation is an antiviral strategy in which toxic fusion proteins are targeted to virions, where they inhibit viral multiplication by destroying viral components. These fusion proteins consist of a virion structural protein moiety and an enzymatic moiety such as a nuclease. Such fusion proteins can severely inhibit transposition of yeast retrotransposon Ty1, an element whose transposition mechanistically resembles retroviral multiplication. We demonstrate that expression of a murine retrovirus capsid-staphylococcal nuclease fusion protein inhibits multiplication of the corresponding murine leukemia virus by 30- to 100-fold. Staphylococcal nuclease is apparently inactive intracellularly and hence nontoxic to the host cell, but it is active extracellularly because of its requirement for high concentrations of Ca2+ ions. Virions assembled in and shed from cells expressing the fusion protein contain very small amounts of intact viral RNA, as would be predicted for nuclease-mediated inhibition of viral multiplication.

  1. Sensitivity to. gamma. rays of avian sarcoma and murine leukemia viruses. [/sup 60/Co, uv

    SciTech Connect

    Toyoshima, K.; Niwa, O.; Yutsudo, M.; Sugiyama, H.; Tahara, S.; Sugahara, T.

    1980-09-01

    The direct inactivation of avian and murine oncoviruses by ..gamma.. rays was examined using /sup 60/Co as a ..gamma..-ray source. The inactivation of murine leukemia virus (M-MuLV) followed single-hit kinetics while the subgroup D Schmidt-Ruppin strain of avian sarcoma virus (SR-RSV D) showed multihit inactivation kinetics with an extrapolation number of 5. The two viruses showed similar uv-inactivation kinetics. The genomic RNA of the SR-RSV D strain was degraded by ..gamma.. irradiation faster than its infectivity, but viral clones isolated from the foci formed after ..gamma.. irradiation had a complete genome. These results suggest that SR-RSV D has a strong repair function, possibly connected with reverse transcriptase activity.

  2. Modeling of Chronic Myeloid Leukemia: An Overview of In Vivo Murine and Human Xenograft Models

    PubMed Central

    Vellenga, Edo

    2016-01-01

    Over the past years, a wide variety of in vivo mouse models have been generated in order to unravel the molecular pathology of Chronic Myeloid Leukemia (CML) and to develop and improve therapeutic approaches. These models range from (conditional) transgenic models, knock-in models, and murine bone marrow retroviral transduction models followed by transplantation. With the advancement of immunodeficient xenograft models, it has become possible to use human stem/progenitor cells for in vivo studies as well as cells directly derived from CML patients. These models not only mimic CML but also have been instrumental in uncovering various fundamental mechanisms of CML disease progression and tyrosine kinase inhibitor (TKI) resistance. With the availability of iPSC technology, it has become feasible to derive, maintain, and expand CML subclones that are at least genetically identical to those in patients. The following review provides an overview of all murine as well as human xenograft models for CML established till date. PMID:27642303

  3. Isolation and Characterization of Mink Cell Focus-Inducing Murine Leukemia Viruses with Xenotropic Host Range from Mouse Strain SL

    PubMed Central

    Adachi, Akio; Sakai, Koji; Ishimoto, Akinori

    1983-01-01

    A new type of mink cell focus-inducing virus was persistently isolated from the leukemic tissues of SL mice. In contrast to the dual tropic mink cell focus-inducing viruses reported to date, the new virus has the host range of the xenotropic murine leukemia virus. Analysis of RNase T1 fingerprints of genomic RNAs suggested that the mink cell focus-inducing virus with the xenotropic host range isolated from SL mice is a recombinant virus deriving from xenotropic murine leukemia virus. Images PMID:6296452

  4. Antileukemic effect of zerumbone-loaded nanostructured lipid carrier in WEHI-3B cell-induced murine leukemia model.

    PubMed

    Rahman, Heshu Sulaiman; Rasedee, Abdullah; How, Chee Wun; Zeenathul, Nazariah Allaudin; Chartrand, Max Stanley; Yeap, Swee Keong; Abdul, Ahmad Bustamam; Tan, Sheau Wei; Othman, Hemn Hassan; Ajdari, Zahra; Namvar, Farideh; Arulselvan, Palanisamy; Fakurazi, Sharida; Mehrbod, Parvaneh; Daneshvar, Nasibeh; Begum, Hasina

    2015-01-01

    Cancer nanotherapy is progressing rapidly with the introduction of many innovative drug delivery systems to replace conventional therapy. Although the antitumor activity of zerumbone (ZER) has been reported, there has been no information available on the effect of ZER-loaded nanostructured lipid carrier (NLC) (ZER-NLC) on murine leukemia cells. In this study, the in vitro and in vivo effects of ZER-NLC on murine leukemia induced with WEHI-3B cells were investigated. The results from 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, Hoechst 33342, Annexin V, cell cycle, and caspase activity assays showed that the growth of leukemia cells in vitro was inhibited by ZER-NLC. In addition, outcomes of histopathology, transmission electron microscopy, and Tdt-mediated dUTP nick-end labeling analyses revealed that the number of leukemia cells in the spleen of BALB/c leukemia mice significantly decreased after 4 weeks of oral treatment with various doses of ZER-NLC. Western blotting and reverse-transcription quantitative polymerase chain reaction assays confirmed the antileukemia effects of ZER-NLC. In conclusion, ZER-NLC was shown to induce a mitochondrial-dependent apoptotic pathway in murine leukemia. Loading of ZER in NLC did not compromise the anticancer effect of the compound, suggesting ZER-NLC as a promising and effective delivery system for treatment of cancers.

  5. Antileukemic effect of zerumbone-loaded nanostructured lipid carrier in WEHI-3B cell-induced murine leukemia model

    PubMed Central

    Rahman, Heshu Sulaiman; Rasedee, Abdullah; How, Chee Wun; Zeenathul, Nazariah Allaudin; Chartrand, Max Stanley; Yeap, Swee Keong; Abdul, Ahmad Bustamam; Tan, Sheau Wei; Othman, Hemn Hassan; Ajdari, Zahra; Namvar, Farideh; Arulselvan, Palanisamy; Fakurazi, Sharida; Mehrbod, Parvaneh; Daneshvar, Nasibeh; Begum, Hasina

    2015-01-01

    Cancer nanotherapy is progressing rapidly with the introduction of many innovative drug delivery systems to replace conventional therapy. Although the antitumor activity of zerumbone (ZER) has been reported, there has been no information available on the effect of ZER-loaded nanostructured lipid carrier (NLC) (ZER-NLC) on murine leukemia cells. In this study, the in vitro and in vivo effects of ZER-NLC on murine leukemia induced with WEHI-3B cells were investigated. The results from 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, Hoechst 33342, Annexin V, cell cycle, and caspase activity assays showed that the growth of leukemia cells in vitro was inhibited by ZER-NLC. In addition, outcomes of histopathology, transmission electron microscopy, and Tdt-mediated dUTP nick-end labeling analyses revealed that the number of leukemia cells in the spleen of BALB/c leukemia mice significantly decreased after 4 weeks of oral treatment with various doses of ZER-NLC. Western blotting and reverse-transcription quantitative polymerase chain reaction assays confirmed the antileukemia effects of ZER-NLC. In conclusion, ZER-NLC was shown to induce a mitochondrial-dependent apoptotic pathway in murine leukemia. Loading of ZER in NLC did not compromise the anticancer effect of the compound, suggesting ZER-NLC as a promising and effective delivery system for treatment of cancers. PMID:25767386

  6. Reversible growth factor dependency and autonomy during murine myelomonocytic leukemia induced by oncogenes

    PubMed Central

    Metcalf, Donald; Glaser, Stefan P.; Xu, Zhen; Di Rago, Ladina; Mifsud, Sandra

    2013-01-01

    When murine fetal liver cells were transduced with either of the human acute myeloid leukemia fusion oncogenes MLL-ENL or MLL-AF9 and then transplanted to irradiated recipient mice, myelomonocyte leukemias rapidly developed from the transplanted cells. Analysis of initial events following transduction showed that both oncogenes immediately induced a wide range of enhanced proliferative states, the most extreme of which could generate continuous lines of cells. Maturation defects accompanied the enhanced proliferative states. At all times, the transformed cells exhibited complete dependency on hematopoietic growth factors, particularly GM-CSF and IL-3. Myelomonocytic leukemic cells from primary or transplanted mice formed colonies in semisolid agar. The large majority were dependent on hematopoietic growth factors, but a low frequency of autonomous colonies was also detected. Unexpectedly, reculture of autonomous leukemic colonies generated large numbers of growth factor-dependent clonogenic progeny. Similarly, transplanted clonal autonomous leukemic cells produced leukemias containing a majority of factor-dependent cells. Conversely, recultures of factor-dependent colonies in vitro always produced small numbers of autonomous colonies among the dependent progeny. The reversible relationship between factor dependency and autonomy is surprising because autonomy would have been presumed to represent the final, irreversible, leukemic state. PMID:24082086

  7. Murine leukemia virus infects early bone marrow progenitors in immunocompetent mice.

    PubMed

    Tumas-Brundage, K M; Garret, W; Blank, K; Prystowsky, M B

    1996-10-15

    Chronic murine leukemia viruses (MuLVs) are retroviruses which induce leukemias/lymphomas after long latency periods. The induction of leukemia by MuLVs is complex, requiring multiple steps beginning with infection of an appropriate target cell. A number of investigators have proposed a bone marrow-thymus axis in the development of retrovirus induced T-cell lymphoma in which cells are initially infected in the bone marrow. These bone marrow cells or their progeny migrate to the thymus during the disease process. In our system using adult, immunocompetent BALB.K mice infected with E-55(+) MuLV, a similar pattern is seen; integrated virus is initially detectable in the bone marrow and spleen and only later in the thymus. In order to better understand the leukemic process, we analyzed the bone marrow from adult, immunocompetent BALB.K mice infected with the E-55(+) MuLV in bone marrow colony assays. The results from these assays demonstrate that either a pluripotent progenitor cell or an early progenitor cell is a target in the bone marrow for the virus.

  8. Intracerebral hemorrhages and syncytium formation induced by endothelial cell infection with a murine leukemia virus.

    PubMed Central

    Park, B H; Lavi, E; Blank, K J; Gaulton, G N

    1993-01-01

    The mechanisms of endothelial cell damage that lead to cerebral hemorrhage are not completely understood. In this study, a cloned murine retrovirus, TR1.3, that uniformly induced stroke in neonatal BALB/c mice is described. Restriction digest mapping suggests that TR1.3 is part of the Friend murine leukemia virus (FMuLV) family. However, unlike mice exposed to other FMuLVs, mice infected with TR1.3 virus developed tremors and seizures within 8 to 18 days postinoculation. This was uniformly followed by paralysis and death within 1 to 2 days. Postmortem examination of TR1.3-inoculated mice revealed edematous brain tissue with large areas of intracerebral hemorrhage. Histologic analysis revealed prominent small vessel pathology including syncytium formation of endothelial cells. Immunohistochemical analysis of frozen brain sections using double fluorescence staining demonstrated that TR1.3 virus specifically infected small vessel endothelial cells. Although infection of vessel endothelial cells was detected in several organs, only brain endothelial cells displayed viral infection associated with hemorrhage. The primary determinant of TR1.3-induced neuropathogenicity was found to reside within a 3.0-kb fragment containing the 3' end of the pol gene, the env gene, and the U3 region of the long terminal repeat. The restricted tropism and acute pathogenicity of this cloned murine retrovirus provide a model for studying virus-induced stroke and for elucidating the mechanisms involved in syncytium formation by retroviruses in vivo. Images PMID:8396666

  9. Flt3 Does Not Play a Critical Role in Murine Myeloid Leukemias Induced by MLL Fusion Genes

    PubMed Central

    Albouhair, Stéphanie; Morgado, Ester; Lavau, Catherine

    2013-01-01

    Leukemias harboring MLL translocations are frequent in children and adults, and respond poorly to therapies. The receptor tyrosine kinase FLT3 is highly expressed in these leukemias. In vitro studies have shown that pediatric MLL-rearranged ALL cells are sensitive to FLT3 inhibitors and clinical trials are ongoing to measure their therapeutic efficacy. We sought to determine the contribution of Flt3 in the pathogenesis of MLL-rearranged leukemias using a myeloid leukemia mouse model. Bone marrow from Flt3 null mice transduced with MLL-ENL or MLL-CBP was transplanted into host mice and Flt3−/− leukemias were compared to their Flt3 wild type counterparts. Flt3 deficiency did not delay disease onset and had minimal impact on leukemia characteristics. To determine the anti-leukemic effect of FLT3 inhibition we studied the sensitivity of MLL-ENL leukemia cells to the FLT3 inhibitor PKC412 ex vivo. As previously reported for human MLL-rearranged leukemias, murine MLL-ENL leukemia cells with higher Flt3 levels were more sensitive to the cytotoxicity of PKC412. Interestingly, Flt3 deficient leukemia samples also displayed some sensitivity to PKC412. Our findings demonstrate that myeloid leukemias induced by MLL-rearranged genes are not dependent upon Flt3 signaling. They also highlight the discrepancy between the sensitivity of cells to Flt3 inhibition in vitro and the lack of contribution of Flt3 to the pathogenesis of MLL-rearranged leukemias in vivo. PMID:23977266

  10. Leukemia

    MedlinePlus

    ... a combination of genetic and environmental factors. How leukemia forms In general, leukemia is thought to occur ... causing the signs and symptoms of leukemia. How leukemia is classified Doctors classify leukemia based on its ...

  11. Leukemia

    MedlinePlus

    ... version of this page please turn Javascript on. Leukemia What Is Leukemia? Leukemia is a cancer of the blood cells. ... diagnosed with leukemia are over 50 years old. Leukemia Starts in Bone Marrow Click for more information ...

  12. Murine Leukemia Virus Uses NXF1 for Nuclear Export of Spliced and Unspliced Viral Transcripts

    PubMed Central

    Sakuma, Toshie; Davila, Jaime I.; Malcolm, Jessica A.; Kocher, Jean-Pierre A.; Tonne, Jason M.

    2014-01-01

    ABSTRACT Intron-containing mRNAs are subject to restricted nuclear export in higher eukaryotes. Retroviral replication requires the nucleocytoplasmic transport of both spliced and unspliced RNA transcripts, and RNA export mechanisms of gammaretroviruses are poorly characterized. Here, we report the involvement of the nuclear export receptor NXF1/TAP in the nuclear export of gammaretroviral RNA transcripts. We identified a conserved cis-acting element in the pol gene of gammaretroviruses, including murine leukemia virus (MLV) and xenotropic murine leukemia virus (XMRV), named the CAE (cytoplasmic accumulation element). The CAE enhanced the cytoplasmic accumulation of viral RNA transcripts and the expression of viral proteins without significantly affecting the stability, splicing, or translation efficiency of the transcripts. Insertion of the CAE sequence also facilitated Rev-independent HIV Gag expression. We found that the CAE sequence interacted with NXF1, whereas disruption of NXF1 ablated CAE function. Thus, the CAE sequence mediates the cytoplasmic accumulation of gammaretroviral transcripts in an NXF1-dependent manner. Disruption of NXF1 expression impaired cytoplasmic accumulations of both spliced and unspliced RNA transcripts of XMRV and MLV, resulting in their nuclear retention or degradation. Thus, our results demonstrate that gammaretroviruses use NXF1 for the cytoplasmic accumulation of both spliced and nonspliced viral RNA transcripts. IMPORTANCE Murine leukemia virus (MLV) has been studied as one of the classic models of retrovirology. Although unspliced host messenger RNAs are rarely exported from the nucleus, MLV actively exports unspliced viral RNAs to the cytoplasm. Despite extensive studies, how MLV achieves this difficult task has remained a mystery. Here, we have studied the RNA export mechanism of MLV and found that (i) the genome contains a sequence which supports the efficient nuclear export of viral RNAs, (ii) the cellular factor NXF1 is

  13. The xenotropic murine leukemia virus-related retrovirus debate continues at first international workshop.

    PubMed

    Stoye, Jonathan P; Silverman, Robert H; Boucher, Charles A; Le Grice, Stuart F J

    2010-12-22

    The 1st International Workshop on Xenotropic Murine Leukemia Virus-Related Retrovirus (XMRV), co-sponsored by the National Institutes of Health, The Department of Health and Human Services and Abbott Diagnostics, was convened on September 7/8, 2010 on the NIH campus, Bethesda, MD. Attracting an international audience of over 200 participants, the 2-day event combined a series of plenary talks with updates on different aspects of XMRV research, addressing basic gammaretrovirus biology, host response, association of XMRV with chronic fatigue syndrome and prostate cancer, assay development and epidemiology. The current status of XMRV research, concerns among the scientific community and suggestions for future actions are summarized in this meeting report.

  14. Tissue selectivity of murine leukemia virus infection is determined by long terminal repeat sequences.

    PubMed Central

    Rosen, C A; Haseltine, W A; Lenz, J; Ruprecht, R; Cloyd, M W

    1985-01-01

    Here we show that the tissue specificity of murine retrovirus infections is determined by the long terminal repeat (LTR) of an otherwise isogenic set of viruses. The isogenic viruses used for this study contain the coding gag, pol, and env genes of the avirulent Akv virus. Recombinant viruses that contain the LTR of a virus that induces T-cell leukemia lymphoma preferentially infect T lymphocytes. Viruses that carry the LTR of a virus that induces erythroleukemia preferentially infect non-T lymphoblastoid cell lines in the marrow and spleen. The Akv virus itself displays no tissue preference for hematopoietic cells. These experiments suggest that retroviruses that carry appropriate enhancer-promoters can be used to infect selectively specific target cells in animals. PMID:2991605

  15. Multiple steps are required for the induction of tumors by Abelson murine leukemia virus.

    PubMed Central

    Green, P L; Kaehler, D A; Bennett, L M; Risser, R

    1989-01-01

    Helper virus-free Abelson murine leukemia virus (A-MuLV) was used to induce monoclonal pre-B-cell tumors in mice. The clonality, patterns of immunoglobulin heavy-chain gene rearrangement, tumorigenicity, and v-abl oncogene expression in individual preleukemic and leukemic colonies were compared. Our results indicate that A-MuLV preleukemic cells with low or undetectable tumorigenic potential give rise to leukemic cells with high tumorigenic potential by a process of subclone selection. The levels of v-abl oncogene product in preleukemic and leukemic cell populations were not significantly different. These results suggest that an additional event(s) unrelated to the level of the v-abl protein product is required for A-MuLV-transformed cells to become fully malignant. Images PMID:2539498

  16. Conditions for Copackaging Rous Sarcoma Virus and Murine Leukemia Virus Gag Proteins during Retroviral Budding

    PubMed Central

    Bennett, Robert P.; Wills, John W.

    1999-01-01

    Rous sarcoma virus (RSV) and murine leukemia virus (MLV) are examples of distantly related retroviruses that normally do not encounter one another in nature. Their Gag proteins direct particle assembly at the plasma membrane but possess very little sequence similarity. As expected, coexpression of these two Gag proteins did not result in particles that contain both. However, when the N-terminal membrane-binding domain of each molecule was replaced with that of the Src oncoprotein, which is also targeted to the cytoplasmic face of the plasma membrane, efficient copackaging was observed in genetic complementation and coimmunoprecipitation assays. We hypothesize that the RSV and MLV Gag proteins normally use distinct locations on the plasma membrane for particle assembly but otherwise have assembly domains that are sufficiently similar in function (but not sequence) to allow heterologous interactions when these proteins are redirected to a common membrane location. PMID:9971785

  17. Removal of xenotropic murine leukemia virus by nanocellulose based filter paper.

    PubMed

    Asper, M; Hanrieder, T; Quellmalz, A; Mihranyan, A

    2015-11-01

    The removal of xenotrpic murine leukemia virus (xMuLV) by size-exclusion filter paper composed of 100% naturally derived cellulose was validated. The filter paper was produced using cellulose nanofibers derived from Cladophora sp. algae. The filter paper was characterized using atomic force microscopy, scanning electron microscopy, helium pycnometry, and model tracer (100 nm latex beads and 50 nm gold nanoparticles) retention tests. Following the filtration of xMuLV spiked solutions, LRV ≥5.25 log10 TCID50 was observed, as limited by the virus titre in the feed solution and sensitivity of the tissue infectivity test. The results of the validation study suggest that the nanocellulose filter paper is useful for removal of endogenous rodent retroviruses and retrovirus-like particles during the production of recombinant proteins.

  18. A flavone derivative from Sesbania sesban leaves and its cytotoxicity against murine leukemia P-388 cells

    SciTech Connect

    Dianhar, Hanhan Syah, Yana Maolana Mujahidin, Didin Hakim, Euis Holisotan Juliawaty, Lia Dewi

    2014-03-24

    Sesbania sesban, locally named as Jayanti, is one of Indonesia plants belonging to Fabaceae family. This species is traditionally used by Indonesian people to cure digestive disorders, fever, or headache. Jayanti can grow well in tropical to subtropical region, such as in Asia and Africa. Based on literature, qualitative analysis of the methanol extract of leaves of S. sesban showed that it contained flavonoids, alkaloids, saponins and glycosides. In addition, the activity assay of extracts of different tissues of this species showed antitumor, antimalarial, and antidiabetic activityies (leaves and seed extracts), antioxidants (flower extract), and analgesic (wood extract). Though the extracts of S. sesban parts showed interesting activities, chemical study of those extracts have not been widely reported. Therefore, the objective of this research was to isolate the secondary metabolites from methanol extract of leaves of S. sesban and to determine their cytotoxicity against murine leukemia P-388 cells. One compound has been obtained and identified as 3-hydroxy-4',7-dimethoxyflavone (1), a new isolated compound from nature. This compound was obtained through separation of methanol extract using various chromatographic techniques, such as vacuum liquid chromatography and radial chromatography. The structure elucidation of isolated compound was based on 1D NMR ({sup 1}H-NMR and {sup 13}C-NMR) and 2D NMR (HMBC). The cytotoxicity of methanol extract and compound 1 against murine leukemia P-388 cells examined through MTT assay showed IC{sub 50} value of 60.04 μg/mL and 5.40 μg/mL, respectively.

  19. A flavone derivative from Sesbania sesban leaves and its cytotoxicity against murine leukemia P-388 cells

    NASA Astrophysics Data System (ADS)

    Dianhar, Hanhan; Syah, Yana Maolana; Mujahidin, Didin; Hakim, Euis Holisotan; Juliawaty, Lia Dewi

    2014-03-01

    Sesbania sesban, locally named as Jayanti, is one of Indonesia plants belonging to Fabaceae family. This species is traditionally used by Indonesian people to cure digestive disorders, fever, or headache. Jayanti can grow well in tropical to subtropical region, such as in Asia and Africa. Based on literature, qualitative analysis of the methanol extract of leaves of S. sesban showed that it contained flavonoids, alkaloids, saponins and glycosides. In addition, the activity assay of extracts of different tissues of this species showed antitumor, antimalarial, and antidiabetic activityies (leaves and seed extracts), antioxidants (flower extract), and analgesic (wood extract). Though the extracts of S. sesban parts showed interesting activities, chemical study of those extracts have not been widely reported. Therefore, the objective of this research was to isolate the secondary metabolites from methanol extract of leaves of S. sesban and to determine their cytotoxicity against murine leukemia P-388 cells. One compound has been obtained and identified as 3-hydroxy-4',7-dimethoxyflavone (1), a new isolated compound from nature. This compound was obtained through separation of methanol extract using various chromatographic techniques, such as vacuum liquid chromatography and radial chromatography. The structure elucidation of isolated compound was based on 1D NMR (1H-NMR and 13C-NMR) and 2D NMR (HMBC). The cytotoxicity of methanol extract and compound 1 against murine leukemia P-388 cells examined through MTT assay showed IC50 value of 60.04 μg/mL and 5.40 μg/mL, respectively.

  20. Murine leukemias with retroviral insertions at Lmo2 are predictive of the leukemias induced in SCID-X1 patients following retroviral gene therapy.

    PubMed

    Davé, Utpal P; Akagi, Keiko; Tripathi, Rati; Cleveland, Susan M; Thompson, Mary A; Yi, Ming; Stephens, Robert; Downing, James R; Jenkins, Nancy A; Copeland, Neal G

    2009-05-01

    Five X-linked severe combined immunodeficiency patients (SCID-X1) successfully treated with autologous bone marrow stem cells infected ex vivo with an IL2RG-containing retrovirus subsequently developed T-cell leukemia and four contained insertional mutations at LMO2. Genetic evidence also suggests a role for IL2RG in tumor formation, although this remains controversial. Here, we show that the genes and signaling pathways deregulated in murine leukemias with retroviral insertions at Lmo2 are similar to those deregulated in human leukemias with high LMO2 expression and are highly predictive of the leukemias induced in SCID-X1 patients. We also provide additional evidence supporting the notion that IL2RG and LMO2 cooperate in leukemia induction but are not sufficient and require additional cooperating mutations. The highly concordant nature of the genetic events giving rise to mouse and human leukemias with mutations at Lmo2 are an encouraging sign to those wanting to use mice to model human cancer and may help in designing safer methods for retroviral gene therapy.

  1. Novel potent inhibitors of the histone demethylase KDM1A (LSD1), orally active in a murine promyelocitic leukemia model.

    PubMed

    Trifirò, Paolo; Cappa, Anna; Brambillasca, Silvia; Botrugno, Oronza A; Cera, Maria Rosaria; Zuffo, Roberto Dal; Dessanti, Paola; Meroni, Giuseppe; Thaler, Florian; Villa, Manuela; Minucci, Saverio; Mercurio, Ciro; Varasi, Mario; Vianello, Paola

    2017-07-01

    Histone lysine demethylases (KDMs) are well-recognized targets in oncology drug discovery. They function at the post-translation level controlling chromatin conformation and gene transcription. KDM1A is a flavin adenine dinucleotide-dependent amine oxidase, overexpressed in several tumor types, including acute myeloid leukemia, neuroblastoma and non-small-cell lung cancer. Among the many known monoamine oxidase inhibitors screened for KDM1A inhibition, tranylcypromine emerged as a moderately active hit, which irreversibly binds to the flavin adenine dinucleotide cofactor. The KDM1A inhibitors 5a-w were synthesized and tested in vitro and in vivo. The biochemical potency was determined, modulation of target in cells was demonstrated on KDM1A-dependent genes and the anti-clonogenic activity was performed in murine acute promyelocytic Leukemia (APL) blasts. An in vivo efficacy experiment was conducted using an established murine promyelocytic leukemia model. We report a new series of tranylcypromine derivatives substituted on the cyclopropyl moiety, endowed with high potency in both biochemical and cellular assays. The most interesting derivative (5a) significantly improved survival rate after oral administration in a murine model of promyelocitic leukemia.

  2. Differential Susceptibility of Spleen Focus-Forming Virus and Murine Leukemia Viruses to Ansamycin Antibiotics

    PubMed Central

    Horoszewicz, Julius S.; Leong, Susan S.; Carter, William A.

    1977-01-01

    The streptovaricin complex (SvCx) and rifamycin SV derivatives display potent antiviral activity against the polycythemic strain of Friend leukemia virus (FV-P), as measured by a reduction in the number of spleen foci produced in mice. Such reductions may be explained by inactivation of functions of (i) the spleen focus-forming virus (SFFV), (ii) its “helper” murine leukemia virus (MuLV), or (iii) both viruses normally present in FV-P. We noted that preincubation of FV-P with fractionation products of SvCx, or derivatives of rifamycin SV, at low concentrations (3 to 5 μg/ml) reduces the number of spleen foci 80 to 97%, whereas titers of MuLV (from the same inoculum) remain unaffected (MuLV titers were measured by XC, S+L−, and “helper activity” assays). Our findings indicate a remarkable biological selectivity of ansamycins, as well as nonansamycin components of SvCx, against the transforming and defective spleen focus-forming virus as compared to MuLV. Thus, the drugs might be useful in distinguishing other types of oncornaviruses. PMID:18986

  3. Effects of murine leukemia virus env gene proteins on macrophage-mediated cytotoxicity in vitro

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Takemoto, L. J.; Spooner, B. S. (Principal Investigator)

    1991-01-01

    F5b Tumor cells were incubated with concentrated culture supernatants taken from cells resistant (F5m) or sensitive (F5b) to contact-dependent macrophage cytotoxicity. Macrophage cell line B6MP102 and murine peritoneal macrophages killed targets incubated with supernatants taken from sensitive cells but poorly killed cells incubated in supernatants isolated from resistant cells. Membranes from cells resistant to macrophage killing, F5m, were fused into F5b cells. The fused F5b cells were killed significantly less than F5b cells fused with F5b cell membranes or untreated F5b cells. The decreased killing of F5b cells corresponded to increased concentrations of gp70(a) molecules on F5b cells. Affinity purified gp70(a) was added to cytotoxicity assays but failed to inhibit macrophage cytotoxicity. P15E molecules were detectable on both F5b and F5m cells. In addition, a synthetic peptide found to exhibit the inhibitory properties of p15E was added to cytotoxicity assays. P15E synthetic peptide also did not inhibit macrophage cytotoxicity. Therefore, env gene proteins of murine leukemia virus do not appear responsible for inducing tumor cell resistance to activated macrophage contact-dependent cytotoxicity.

  4. Immunotherapy of murine leukemia. Efficacy of passive serum therapy of Friend leukemia virus-induced disease in immunocompromised mice

    SciTech Connect

    Genovesi, E.V.; Livnat, D.; Collins, J.J.

    1983-02-01

    Previous studies have demonstrated that the passive therapy of Friend murine leukemia virus (F-MuLV)-induced disease with chimpanzee anti-F-MuLV serum is accompanied by the development of host antiviral humoral and cellular immunity, the latter measurable in adoptive transfer protocols and by the ability of serum-protected mice to resist virus rechallenge. The present study was designed to further examine the contribution of various compartments of the host immune system to serum therapy itself, as well as to the acquired antiviral immunity that develops in serum-protected mice, through the use of naturally immunocompromised animals (e.g., nude athymic mice and natural killer (NK)-deficient beige mutant mice) or mice treated with immunoabrogating agents such as sublethal irradiation, cyclophosphamide (Cytoxan (Cy)), cortisone, and /sup 89/Sr. The studies in nude mice indicate that while mature T-cells are not needed for effective serum therapy, they do appear to be necessary for the long-term resistance of serum-protected mice to virus rechallenge and for the generation of the cell population(s) responsible for adoptive transfer of antiviral immunity. Furthermore, this acquired resistance is not due to virus neutralization by serum antibodies since antibody-negative, Cy-treated, serum-protected mice still reject the secondary virus infection. Lastly, while the immunocompromise systems examined did effect various host antiviral immune responses, none of them, including the NK-deficient beige mutation, significantly diminished the efficacy of the passive serum therapy of F-MuLV-induced disease.

  5. Structural and biochemical characterization of the inhibitor complexes of xenotropic murine leukemia virus-related virus protease

    SciTech Connect

    Li, Mi; Gustchina, Alla; Matúz, Krisztina; Tözsér, Jozsef; Namwong, Sirilak; Goldfarb, Nathan E.; Dunn, Ben M.; Wlodawer, Alexander

    2012-10-23

    Interactions between the protease (PR) encoded by the xenotropic murine leukemia virus-related virus and a number of potential inhibitors have been investigated by biochemical and structural techniques. It was observed that several inhibitors used clinically against HIV PR exhibit nanomolar or even subnanomolar values of K{sub i}, depending on the exact experimental conditions. Both TL-3, a universal inhibitor of retroviral PRs, and some inhibitors originally shown to inhibit plasmepsins were also quite potent, whereas inhibition by pepstatin A was considerably weaker. Crystal structures of the complexes of xenotropic murine leukemia virus-related virus PR with TL-3, amprenavir and pepstatin A were solved at high resolution and compared with the structures of complexes of these inhibitors with other retropepsins. Whereas TL-3 and amprenavir bound in a predictable manner, spanning the substrate-binding site of the enzyme, two molecules of pepstatin A bound simultaneously in an unprecedented manner, leaving the catalytic water molecule in place.

  6. Organization, distribution, and stability of endogenous ecotropic murine leukemia virus DNA sequences in chromosomes of Mus musculus.

    PubMed Central

    Jenkins, N A; Copeland, N G; Taylor, B A; Lee, B K

    1982-01-01

    The endogenous ecotropic murine leukemia virus DNA content and integration sites were characterized for 54 inbred strains and substrains of mice by restriction enzyme digestion, Southern blotting, and hybridization with an ecotropic murine leukemia virus DNA-specific probe. More than 75% of these strains carried endogenous ecotropic proviruses which were located in at least 29 distinct integration sites in chromosomes of Mus musculus. Fourteen of these proviruses have been assigned specific locus designations. Most, but not all, of the endogenous ecotropic proviruses were structurally indistinguishable by this analysis from the prototype AKR ecotropic virus, and the distribution of these proviruses followed known relationships among the inbred strains and substrains of mice. These results suggest that, in general, viral DNA integration preceded the establishment of inbred mouse strains and that these integrations are relatively stable. Images PMID:6287001

  7. Molecular cloning of osteoma-inducing replication-competent murine leukemia viruses from the RFB osteoma virus stock.

    PubMed Central

    Pedersen, L; Behnisch, W; Schmidt, J; Luz, A; Pedersen, F S; Erfle, V; Strauss, P G

    1992-01-01

    We report the molecular cloning of two replication-competent osteoma-inducing murine leukemia viruses from the RFB osteoma virus stock (M. P. Finkel, C. A. Reilly, Jr., B. O. Biskis, and I. L. Greco, p. 353-366, in C. H. G. Price and F. G. M. Ross, ed., Bone--Certain Aspects of Neoplasia, 1973). Like the original RFB osteoma virus stock, viruses derived from the molecular RFB clones induced multiple osteomas in mice of the CBA/Ca strain. The cloned RFB viruses were indistinguishable by restriction enzyme analysis and by nucleotide sequence analysis of their long-terminal-repeat regions and showed close relatedness to the Akv murine leukemia virus. Images PMID:1326664

  8. Cellular RNA homologous to the Abelson murine leukemia virus transforming gene: expression and relationship to the viral sequence.

    PubMed Central

    Wang, J Y; Baltimore, D

    1983-01-01

    To examine the expression of the cellular homolog of the Abelson murine leukemia virus transforming gene (the v-abl sequence), a DNA probe representing the v-abl sequence was prepared. The probe detected two cytoplasmic polyadenylic acid-containing c-abl RNAs of about 6.5 and 5.5 kilobases in a variety of rodent cells, and slightly larger RNAs were detected in human cells. These two RNA species were found in all normal tissues or cell lines examined, but at differing concentrations: liver cells had the least, fibroblastic cell lines had the most. By using a probe able to detect the cellular but not the viral gene, the two RNAs were shown to be present in Abelson murine leukemia virus-transformed cells at levels found either in their untransformed counterparts or in similar cell types transformed by other means. The target cells of the virus have a somewhat elevated level of the two RNAs although expression of the c-abl gene is not restricted to these cells. The v-abl sequence lacks 0.35 and 0.85 kilobases of the c-abl RNA on the 5' and 3' ends, respectively. Thus, the Abelson murine leukemia virus transforming gene is an internal fragment of the transcript of a normal cellular gene. Images PMID:6306446

  9. NMR study of xenotropic murine leukemia virus-related virus protease in a complex with amprenavir

    SciTech Connect

    Furukawa, Ayako; Okamura, Hideyasu; Morishita, Ryo; Matsunaga, Satoko; Kobayashi, Naohiro; Ikegami, Takahisa; Kodaki, Tsutomu; Takaori-Kondo, Akifumi; Ryo, Akihide; Nagata, Takashi; Katahira, Masato

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Protease (PR) of XMR virus (XMRV) was successfully synthesized with cell-free system. Black-Right-Pointing-Pointer Interface of XMRV PR with an inhibitor, amprenavir (APV), was identified with NMR. Black-Right-Pointing-Pointer Structural heterogeneity is induced for two PR protomers in the APV:PR = 1:2 complex. Black-Right-Pointing-Pointer Structural heterogeneity is transmitted even to distant regions from the interface. Black-Right-Pointing-Pointer Long-range transmission of structural change may be utilized for drug discovery. -- Abstract: Xenotropic murine leukemia virus-related virus (XMRV) is a virus created through recombination of two murine leukemia proviruses under artificial conditions during the passage of human prostate cancer cells in athymic nude mice. The homodimeric protease (PR) of XMRV plays a critical role in the production of functional viral proteins and is a prerequisite for viral replication. We synthesized XMRV PR using the wheat germ cell-free expression system and carried out structural analysis of XMRV PR in a complex with an inhibitor, amprenavir (APV), by means of NMR. Five different combinatorially {sup 15}N-labeled samples were prepared and backbone resonance assignments were made by applying Otting's method, with which the amino acid types of the [{sup 1}H, {sup 15}N] HSQC resonances were automatically identified using the five samples (Wu et al., 2006) . A titration experiment involving APV revealed that one APV molecule binds to one XMRV PR dimer. For many residues, two distinct resonances were observed, which is thought to be due to the structural heterogeneity between the two protomers in the APV:XMRV PR = 1:2 complex. PR residues at the interface with APV have been identified on the basis of chemical shift perturbation and identification of the intermolecular NOEs by means of filtered NOE experiments. Interestingly, chemical shift heterogeneity between the two protomers of XMRV PR has

  10. Ecotropic Murine Leukemia Virus Infection of Glial Progenitors Interferes with Oligodendrocyte Differentiation: Implications for Neurovirulence

    PubMed Central

    Li, Ying; Dunphy, Jaclyn M.; Pedraza, Carlos E.; Lynch, Connor R.; Cardona, Sandra M.; Macklin, Wendy B.

    2016-01-01

    ABSTRACT Certain murine leukemia viruses (MLVs) are capable of inducing fatal progressive spongiform motor neuron disease in mice that is largely mediated by viral Env glycoprotein expression within central nervous system (CNS) glia. While the etiologic mechanisms and the glial subtypes involved remain unresolved, infection of NG2 glia was recently observed to correlate spatially and temporally with altered neuronal physiology and spongiogenesis. Since one role of NG2 cells is to serve as oligodendrocyte (OL) progenitor cells (OPCs), we examined here whether their infection by neurovirulent (FrCasE) or nonneurovirulent (Fr57E) ecotropic MLVs influenced their viability and/or differentiation. Here, we demonstrate that OPCs, but not OLs, are major CNS targets of both FrCasE and Fr57E. We also show that MLV infection of neural progenitor cells (NPCs) in culture did not affect survival, proliferation, or OPC progenitor marker expression but suppressed certain glial differentiation markers. Assessment of glial differentiation in vivo using transplanted transgenic NPCs showed that, while MLVs did not affect cellular engraftment or survival, they did inhibit OL differentiation, irrespective of MLV neurovirulence. In addition, in chimeric brains, where FrCasE-infected NPC transplants caused neurodegeneration, the transplanted NPCs proliferated. These results suggest that MLV infection is not directly cytotoxic to OPCs but rather acts to interfere with OL differentiation. Since both FrCasE and Fr57E viruses restrict OL differentiation but only FrCasE induces overt neurodegeneration, restriction of OL maturation alone cannot account for neuropathogenesis. Instead neurodegeneration may involve a two-hit scenario where interference with OPC differentiation combined with glial Env-induced neuronal hyperexcitability precipitates disease. IMPORTANCE A variety of human and animal retroviruses are capable of causing central nervous system (CNS) neurodegeneration manifested as motor

  11. Endogenous murine leukemia retroviral variation across wild European and inbred strains of house mouse.

    PubMed

    Hartmann, Stefanie; Hasenkamp, Natascha; Mayer, Jens; Michaux, Johan; Morand, Serge; Mazzoni, Camila J; Roca, Alfred L; Greenwood, Alex D

    2015-08-18

    Endogenous murine leukemia retroviruses (MLVs) are high copy number proviral elements difficult to comprehensively characterize using standard low throughput sequencing approaches. However, high throughput approaches generate data that is challenging to process, interpret and present. Next generation sequencing (NGS) data was generated for MLVs from two wild caught Mus musculus domesticus (from mainland France and Corsica) and for inbred laboratory mouse strains C3H, LP/J and SJL. Sequence reads were grouped using a novel sequence clustering approach as applied to retroviral sequences. A Markov cluster algorithm was employed, and the sequence reads were queried for matches to specific xenotropic (Xmv), polytropic (Pmv) and modified polytropic (Mpmv) viral reference sequences. Various MLV subtypes were more widespread than expected among the mice, which may be due to the higher coverage of NGS, or to the presence of similar sequence across many different proviral loci. The results did not correlate with variation in the major MLV receptor Xpr1, which can restrict exogenous MLVs, suggesting that endogenous MLV distribution may reflect gene flow more than past resistance to infection.

  12. Greying with age in mice: relation to expression of murine leukemia viruses.

    PubMed

    Morse, H C; Yetter, R A; Stimpfling, J H; Pitts, O M; Fredrickson, T N; Hartley, J W

    1985-06-01

    Some strains of C57BL/10 H-2-congenic mice were found to exhibit greying with age, whereas others did not. Two patterns of greying were observed, diffuse greying beginning at 4 to 6 months of age and patterned greying beginning at 4 to 6 weeks. Strains exhibiting either greying pattern expressed high levels of infectious ecotropic and mink cell focus-inducing murine leukemia viruses (MuLV) in tests of thymus and spleen and in cultures from skin or tail biopsies, whereas nongreying strains expressed little virus until late in life. Electron microscopy demonstrated large accumulations of MuLV in grey, but not in black areas, of skin from a mouse with patterned greying. Infectious MuLV was produced spontaneously by embryos of greying, but not of nongreying, mice and pups of nongreying strains fostered on greying mothers turned grey after 3 months. These results suggest that greying with age results from melanocyte dysfunction that occurs subsequent to pre- or early postnatal infection with MuLV.

  13. Biochemical, inhibition and inhibitor resistance studies of xenotropic murine leukemia virus-related virus reverse transcriptase

    PubMed Central

    Ndongwe, Tanyaradzwa P.; Adedeji, Adeyemi O.; Michailidis, Eleftherios; Ong, Yee Tsuey; Hachiya, Atsuko; Marchand, Bruno; Ryan, Emily M.; Rai, Devendra K.; Kirby, Karen A.; Whatley, Angela S.; Burke, Donald H.; Johnson, Marc; Ding, Shilei; Zheng, Yi-Min; Liu, Shan-Lu; Kodama, Ei-Ichi; Delviks-Frankenberry, Krista A.; Pathak, Vinay K.; Mitsuya, Hiroaki; Parniak, Michael A.; Singh, Kamalendra; Sarafianos, Stefan G.

    2012-01-01

    We report key mechanistic differences between the reverse transcriptases (RT) of human immunodeficiency virus type-1 (HIV-1) and of xenotropic murine leukemia virus-related virus (XMRV), a gammaretrovirus that can infect human cells. Steady and pre-steady state kinetics demonstrated that XMRV RT is significantly less efficient in DNA synthesis and in unblocking chain-terminated primers. Surface plasmon resonance experiments showed that the gammaretroviral enzyme has a remarkably higher dissociation rate (koff) from DNA, which also results in lower processivity than HIV-1 RT. Transient kinetics of mismatch incorporation revealed that XMRV RT has higher fidelity than HIV-1 RT. We identified RNA aptamers that potently inhibit XMRV, but not HIV-1 RT. XMRV RT is highly susceptible to some nucleoside RT inhibitors, including Translocation Deficient RT inhibitors, but not to non-nucleoside RT inhibitors. We demonstrated that XMRV RT mutants K103R and Q190M, which are equivalent to HIV-1 mutants that are resistant to tenofovir (K65R) and AZT (Q151M), are also resistant to the respective drugs, suggesting that XMRV can acquire resistance to these compounds through the decreased incorporation mechanism reported in HIV-1. PMID:21908397

  14. Xenotropic Murine Leukemia Virus-Related Virus in Chronic Fatigue Syndrome and Prostate Cancer

    PubMed Central

    2010-01-01

    Xenotropic murine leukemia virus-related virus (XMRV) is a γ retrovirus that has been associated with chronic fatigue syndrome (CFS) and prostate cancer. The search for viral causes of these syndromes was reignited by the finding that RNase L activity was low in hereditary prostate cancer and some CFS patients. The six strains of XMRV that have been sequenced have greater than 99% identity, indicating a new human infection rather than laboratory contamination. DNA, RNA, and proteins from XMRV have been detected in 50% to 67% of CFS patients and in about 3.7% of healthy controls. XMRV infections could be transmitted to permissive cell lines from CFS plasma, suggesting the potential for communicable and blood-borne spread of the virus and potentially CFS. This troubling concept is currently under intense evaluation. The most important steps now are to independently confirm the initial findings; develop reliable assays of biomarkers; and to move on to investigations of XMRV pathophysiology and treatment in CFS, prostate cancer, and potentially other virus-related syndromes, if they exist. PMID:20425007

  15. Insights into the nuclear export of murine leukemia virus intron-containing RNA.

    PubMed

    Pessel-Vivares, Lucie; Houzet, Laurent; Lainé, Sébastien; Mougel, Marylène

    2015-01-01

    The retroviral genome consists of an intron-containing transcript that has essential cytoplasmic functions in the infected cell. This viral transcript can escape splicing, circumvent the nuclear checkpoint mechanisms and be transported to the cytoplasm by hijacking the host machinery. Once in the cytoplasm, viral unspliced RNA acts as mRNA to be translated and as genomic RNA to be packaged into nascent viruses. The murine leukemia virus (MLV) is among the first retroviruses discovered and is classified as simple Retroviridae due to its minimal encoding capacity. The oncogenic and transduction abilities of MLV are extensively studied, whereas surprisingly the crucial step of its nuclear export has remained unsolved until 2014. Recent work has revealed the recruitment by MLV of the cellular NXF1/Tap-dependent pathway for export. Unconventionally, MLV uses of Tap to export both spliced and unspliced viral RNAs. Unlike other retroviruses, MLV does not harbor a unique RNA signal for export. Indeed, multiple sequences throughout the MLV genome appear to promote export of the unspliced MLV RNA. We review here the current understanding of the export mechanism and highlight the determinants that influence MLV export. As the molecular mechanism of MLV export is elucidated, we will gain insight into the contribution of the export pathway to the cytoplasmic fate of the viral RNA.

  16. Murine leukemia virus uses TREX components for efficient nuclear export of unspliced viral transcripts.

    PubMed

    Sakuma, Toshie; Tonne, Jason M; Ikeda, Yasuhiro

    2014-03-10

    Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV) transcripts depends on the nuclear export factor (NXF1) pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.

  17. Epigenetic changes during disease progression in a murine model of human chronic lymphocytic leukemia

    PubMed Central

    Chen, Shih-Shih; Raval, Aparna; Johnson, Amy J.; Hertlein, Erin; Liu, Te-Hui; Jin, Victor X.; Sherman, Mara H.; Liu, Shu-Jun; Dawson, David W.; Williams, Katie E.; Lanasa, Mark; Liyanarachchi, Sandya; Lin, Thomas S.; Marcucci, Guido; Pekarsky, Yuri; Davuluri, Ramana; Croce, Carlo M.; Guttridge, Denis C.; Teitell, Michael A.; Byrd, John C.; Plass, Christoph

    2009-01-01

    Epigenetic alterations, including gain or loss of DNA methylation, are a hallmark of nearly every malignancy. Changes in DNA methylation can impact expression of cancer-related genes including apoptosis regulators and tumor suppressors. Because such epigenetic changes are reversible, they are being aggressively investigated as potential therapeutic targets. Here we use the Eμ-TCL1 transgenic mouse model of chronic lymphocytic leukemia (CLL) to determine the timing and patterns of aberrant DNA methylation, and to investigate the mechanisms that lead to aberrant DNA methylation. We show that CLL cells from Eμ-TCL1 mice at various stages recapitulate epigenetic alterations seen in human CLL. Aberrant methylation of promoter sequences is observed as early as 3 months of age in these animals, well before disease onset. Abnormally methylated promoter regions include binding sites for the transcription factor FOXD3. We show that loss of Foxd3 expression due to an NF-κB p50/p50:HDAC1 repressor complex occurs in TCL1-positive B cells before methylation. Therefore, specific transcriptional repression is an early event leading to epigenetic silencing of target genes in murine and human CLL. These results provide strong rationale for the development of strategies to target NF-κB components in CLL and potentially other B-cell malignancies. PMID:19666576

  18. Epigenetic changes during disease progression in a murine model of human chronic lymphocytic leukemia.

    PubMed

    Chen, Shih-Shih; Raval, Aparna; Johnson, Amy J; Hertlein, Erin; Liu, Te-Hui; Jin, Victor X; Sherman, Mara H; Liu, Shu-Jun; Dawson, David W; Williams, Katie E; Lanasa, Mark; Liyanarachchi, Sandya; Lin, Thomas S; Marcucci, Guido; Pekarsky, Yuri; Davuluri, Ramana; Croce, Carlo M; Guttridge, Denis C; Teitell, Michael A; Byrd, John C; Plass, Christoph

    2009-08-11

    Epigenetic alterations, including gain or loss of DNA methylation, are a hallmark of nearly every malignancy. Changes in DNA methylation can impact expression of cancer-related genes including apoptosis regulators and tumor suppressors. Because such epigenetic changes are reversible, they are being aggressively investigated as potential therapeutic targets. Here we use the Emu-TCL1 transgenic mouse model of chronic lymphocytic leukemia (CLL) to determine the timing and patterns of aberrant DNA methylation, and to investigate the mechanisms that lead to aberrant DNA methylation. We show that CLL cells from Emu-TCL1 mice at various stages recapitulate epigenetic alterations seen in human CLL. Aberrant methylation of promoter sequences is observed as early as 3 months of age in these animals, well before disease onset. Abnormally methylated promoter regions include binding sites for the transcription factor FOXD3. We show that loss of Foxd3 expression due to an NF-kappaB p50/p50:HDAC1 repressor complex occurs in TCL1-positive B cells before methylation. Therefore, specific transcriptional repression is an early event leading to epigenetic silencing of target genes in murine and human CLL. These results provide strong rationale for the development of strategies to target NF-kappaB components in CLL and potentially other B-cell malignancies.

  19. Antiretroviral activities of protease inhibitors against murine leukemia virus and simian immunodeficiency virus in tissue culture.

    PubMed

    Black, P L; Downs, M B; Lewis, M G; Ussery, M A; Dreyer, G B; Petteway, S R; Lambert, D M

    1993-01-01

    Rationally designed synthetic inhibitors of retroviral proteases inhibit the processing of viral polyproteins in cultures of human immunodeficiency virus type 1 (HIV-1)-infected T lymphocytes and, as a result, inhibit the infectivity of HIV-1 for such cultures. The ability of HIV-1 protease inhibitors to suppress replication of the C-type retrovirus Rauscher murine leukemia virus (R-MuLV) and the HIV-related lentivirus simian immunodeficiency virus (SIV) was examined in plaque reduction assays and syncytium reduction assays, respectively. Three of seven compounds examined blocked production of infectious R-MuLV, with 50% inhibitory concentrations of < or = 1 microM. Little or no cellular cytotoxicity was detectable at concentrations up to 100 microM. The same compounds which inhibited the infectivity of HIV-1 also produced activity against SIV and R-MuLV. Electron microscopic examination revealed the presence of many virions with atypical morphologies in cultures treated with the active compounds. Morphometric analysis demonstrated that the active compounds reduced the number of membrane-associated virus particles. These results demonstrate that synthetic peptide analog inhibitors of retroviral proteases significantly inhibit proteolytic processing of the gag polyproteins of R-MuLV and SIV and inhibit the replication of these retroviruses. These results are similar to those for inhibition of HIV-1 infectivity by these compounds, and thus, R-MuLV and SIV might be suitable models for the in vivo evaluation of the antiretroviral activities of these protease inhibitors.

  20. Antiretroviral activities of protease inhibitors against murine leukemia virus and simian immunodeficiency virus in tissue culture.

    PubMed Central

    Black, P L; Downs, M B; Lewis, M G; Ussery, M A; Dreyer, G B; Petteway, S R; Lambert, D M

    1993-01-01

    Rationally designed synthetic inhibitors of retroviral proteases inhibit the processing of viral polyproteins in cultures of human immunodeficiency virus type 1 (HIV-1)-infected T lymphocytes and, as a result, inhibit the infectivity of HIV-1 for such cultures. The ability of HIV-1 protease inhibitors to suppress replication of the C-type retrovirus Rauscher murine leukemia virus (R-MuLV) and the HIV-related lentivirus simian immunodeficiency virus (SIV) was examined in plaque reduction assays and syncytium reduction assays, respectively. Three of seven compounds examined blocked production of infectious R-MuLV, with 50% inhibitory concentrations of < or = 1 microM. Little or no cellular cytotoxicity was detectable at concentrations up to 100 microM. The same compounds which inhibited the infectivity of HIV-1 also produced activity against SIV and R-MuLV. Electron microscopic examination revealed the presence of many virions with atypical morphologies in cultures treated with the active compounds. Morphometric analysis demonstrated that the active compounds reduced the number of membrane-associated virus particles. These results demonstrate that synthetic peptide analog inhibitors of retroviral proteases significantly inhibit proteolytic processing of the gag polyproteins of R-MuLV and SIV and inhibit the replication of these retroviruses. These results are similar to those for inhibition of HIV-1 infectivity by these compounds, and thus, R-MuLV and SIV might be suitable models for the in vivo evaluation of the antiretroviral activities of these protease inhibitors. Images PMID:8381640

  1. Insights into the nuclear export of murine leukemia virus intron-containing RNA

    PubMed Central

    Pessel-Vivares, Lucie; Houzet, Laurent; Lainé, Sébastien; Mougel, Marylène

    2015-01-01

    The retroviral genome consists of an intron-containing transcript that has essential cytoplasmic functions in the infected cell. This viral transcript can escape splicing, circumvent the nuclear checkpoint mechanisms and be transported to the cytoplasm by hijacking the host machinery. Once in the cytoplasm, viral unspliced RNA acts as mRNA to be translated and as genomic RNA to be packaged into nascent viruses. The murine leukemia virus (MLV) is among the first retroviruses discovered and is classified as simple Retroviridae due to its minimal encoding capacity. The oncogenic and transduction abilities of MLV are extensively studied, whereas surprisingly the crucial step of its nuclear export has remained unsolved until 2014. Recent work has revealed the recruitment by MLV of the cellular NXF1/Tap-dependent pathway for export. Unconventionally, MLV uses of Tap to export both spliced and unspliced viral RNAs. Unlike other retroviruses, MLV does not harbor a unique RNA signal for export. Indeed, multiple sequences throughout the MLV genome appear to promote export of the unspliced MLV RNA. We review here the current understanding of the export mechanism and highlight the determinants that influence MLV export. As the molecular mechanism of MLV export is elucidated, we will gain insight into the contribution of the export pathway to the cytoplasmic fate of the viral RNA. PMID:26158194

  2. Xenotropic Murine Leukemia Virus-Related Virus in Monozygotic Twins Discordant for Chronic Fatigue Syndrome

    PubMed Central

    Jerome, Keith R.; Diem, Kurt; Huang, Meei-Li; Selke, Stacy; Corey, Lawrence; Buchwald, Dedra

    2011-01-01

    A recent report suggested an association between xenotropic murine leukemia virus-related virus (XMRV) and chronic fatigue syndrome (CFS). If confirmed, this would suggest that antiretroviral therapy might benefit patients suffering from CFS. We validated a set of assays for XMRV, and evaluated the prevalence of XMRV in a cohort of monozygotic twins discordant for CFS. Stored PBMC were tested with 3 separate PCR assays (one of which was nested) for XMRV DNA, and serum/plasma was tested for XMRV RNA by reverse transcription (RT)-PCR. None of the PBMC samples from the twins with CFS or their unaffected co-twins were positive for XMRV, by any of the assays. One plasma sample, from an unaffected co-twin, was reproducibly positive by RT-PCR. However, serum from the same day was negative, as was a followup plasma sample obtained 2 days after the positive specimen. These data do not support an association of XMRV with CFS. PMID:21795004

  3. Small synthetic ligands for the enrichment of viral particles pseudotyped with amphotropic murine leukemia virus envelope.

    PubMed

    Fernandes, Cláudia S M; Castro, Rute; Coroadinha, Ana Sofia; Roque, A Cecília A

    2016-03-18

    Retroviral vectors gained popularity toward other viral vectors as they integrate their genome into hosts' genome, a characteristic required for the modification of stem cells. However, the production of viable particles for gene therapy is hampered by the low ratio of infectious to non-infectious viral particles after purification, low titers and limited number of competent viral receptors. We have developed de novo two fully synthetic triazine-based ligands that can selectively bind retroviral particles pseudotyped with amphotropic murine leukemia virus envelope (AMPHO4070A). A 78-membered library of triazine-based ligands was designed in silico and was virtually screened against the modeled structure of the AMPHO4070A protein. Ligands displaying the highest energy of binding were synthesized on cross-linked agarose and experimentally tested. Adsorbents containing ligands A5A10 and A10A11 showed selectivity toward viral particles containing the target protein (VLP-AMPHO), binding 19 ± 5 μg/g support and 47 ± 13 μg/g support, respectively. The elution conditions for both ligands were mild and with high recovery yields (80-100%), in comparison with common purification practices. These results were based on a lab-scale experimental setting with VLP integrity being confirmed through TEM. In particular, the elution buffer containing 12 mM imidazole allowed the recovery of intact amphotropic viral particles.

  4. Murine Leukemia Virus (MLV)-based Coronavirus Spike-pseudotyped Particle Production and Infection

    PubMed Central

    Millet, Jean Kaoru; Whittaker, Gary R.

    2016-01-01

    Viral pseudotyped particles (pp) are enveloped virus particles, typically derived from retroviruses or rhabdoviruses, that harbor heterologous envelope glycoproteins on their surface and a genome lacking essential genes. These synthetic viral particles are safer surrogates of native viruses and acquire the tropism and host entry pathway characteristics governed by the heterologous envelope glycoprotein used. They have proven to be very useful tools used in research with many applications, such as enabling the study of entry pathways of enveloped viruses and to generate effective gene-delivery vectors. The basis for their generation lies in the capacity of some viruses, such as murine leukemia virus (MLV), to incorporate envelope glycoproteins of other viruses into a pseudotyped virus particle. These can be engineered to contain reporter genes such as luciferase, enabling quantification of virus entry events upon pseudotyped particle infection with susceptible cells. Here, we detail a protocol enabling generation of MLV-based pseudotyped particles, using the Middle East respiratory syndrome coronavirus (MERS-CoV) spike (S) as an example of a heterologous envelope glycoprotein to be incorporated. We also describe how these particles are used to infect susceptible cells and to perform a quantitative infectivity readout by a luciferase assay. PMID:28018942

  5. Altered transcription of genes coding for class I histocompatibility antigens in murine tumor cells

    PubMed Central

    1983-01-01

    Three murine tumors induced by Moloney murine leukemia virus (M-MLV) which exhibited loss of some or all H-2 class I antigens at the cell surface were analyzed at the DNA and RNA level with molecular probes specific of H-2 heavy chains and beta 2-microglobulin sequences. No observable difference could be detected at the DNA level between the tumors and the parent animals. However, a decrease in H-2 mRNA was observed, especially in phenotypically H-2 negative tumor, BM5R, where H-2 transcripts were at least 30-fold less abundant. These results show that an H-2-negative character may result from a general alteration in the transcription of H-2 genes, which could reflect some kind of regulatory process. PMID:6311935

  6. Detection of receptor-specific murine leukemia virus binding to cells by immunofluorescence analysis.

    PubMed Central

    Kadan, M J; Sturm, S; Anderson, W F; Eglitis, M A

    1992-01-01

    Four classes of murine leukemia virus (MuLV) which display distinct cellular tropisms and bind to different retrovirus receptors to initiate virus infection have been described. In the present study, we describe a rapid, sensitive immunofluorescence assay useful for characterizing the initial binding of MuLV to cells. By using the rat monoclonal antibody 83A25 (L. H. Evans, R. P. Morrison, F. G. Malik, J. Portis, and W. J. Britt, J. Virol. 64:6176-6183, 1990), which recognizes an epitope of the envelope gp70 molecule common to the different classes of MuLV, it is possible to analyse the binding of ecotropic, amphotropic, or xenotropic MuLV by using only a single combination of primary and secondary antibodies. The MuLV binding detected by this assay is envelope receptor specific and matches the susceptibility to infection determined for cells from a variety of species. The binding of amphotropic MuLV to NIH 3T3 cells was shown to be rapid, saturable, and temperature dependent. Chinese hamster ovary (CHO-K1) cells normally lack the ability to bind ecotropic virus and are not infectible by ecotropic vectors. Expression of the cloned ecotropic retrovirus receptor gene (Rec) in CHO-K1 cells confers high levels of ecotropic virus-specific binding and confers susceptibility to infection. Characterization of MuLV binding to primary cells may provide insight into the infectibility of cells by retroviruses and aid in the selection of appropriate vectors for gene transfer experiments. PMID:1312632

  7. Frequent detection of infectious xenotropic murine leukemia virus (XMLV) in human cultures established from mouse xenografts

    PubMed Central

    Zhang, Yu-An; Maitra, Anirban; Hsieh, Jer-Tsong; Rudin, Charles M; Peacock, Craig D; Karikari, Collins; Brekken, Rolf A; Stastny, Victor; Gao, Boning; Girard, Luc; Wistuba, Ignacio; Frenkel, Eugene; Minna, John D

    2011-01-01

    Purpose To investigate the frequency of xenotropic murine leukemia virus (MLV) presence in human cell lines established from mouse xenografts and to search for the evidence of horizontal viral spread to other cell lines. Results Six of 23 (26%) mouse DNA free xenograft cultures were strongly positive for MLV and their sequences had greater than 99% homology to known MLV strains. Four of five available supernatant fluids from these viral positive cultures were strongly positive for RT activity. Three of these supernatant fluids were studied to confirm the infectivity of the released virions for other human culture cells. Of the 78 non-xenograft derived cell lines maintained in the xenograft culture-containing facilities, 13 (17%) were positive for MLV, including XMRV, a virus strain first identified in human tissues. By contrast, all 50 cultures maintained in a xenograft culture-free facility were negative for viral sequences. Methodology We examined xenograft tumor cell lines from seven independent laboratories and 128 non-xenografted tumor cell lines. Cell line DNA was examined for mouse DNA contamination, and by 3 Taqman qPCR assays targeting the gag, env or pol regions of MLV. Sequencing was used for viral strain identification. Supernatant fluids were tested for reverse transcriptase (RT) activity. Conclusions Human cultures derived after mouse xenografting frequently contain and release highly infectious xenotropic MLV viruses. Laboratories working with xenograft-derived human cultures should be aware of the risk of contamination with potentially biohazardous human-tropic mouse viruses and their horizontal spread to other cultures. PMID:21750403

  8. Abelson murine leukemia virus transformation-defective mutants with impaired P120-associated protein kinase activity.

    PubMed Central

    Reynolds, F H; Van de Ven, W J; Stephenson, J R

    1980-01-01

    Several transformation-defective (td) mutants of Abelson murine leukemia virus (AbLV) are described. Cells nonproductively infected with such mutants exhibited a high degree of growth contact inhibition, failed to form colonies in soft agar, lacked rescuable transforming virus, and were as susceptible as uninfected control cells to transformation by wild-type (wt) AbLV pseudotype virus. In addition, each of several td AbLV nonproductively infected cell clones analyzed was found to be nontumorigenic in vivo. Biochemical analysis of td mutant AbLV-infected clones revealed levels of expression of the major AbLV translational product, P120, and a highly related 80,000-Mr AbLV-encoded protein, P80, at concentrations analogous to those in wt AbLV-transformed cells. Although the AbLV-specific 120,000-Mr polyproteins expressed in td mutant AbLV-infected clones were indistinguishable from those in wt AbLV-transformed lines with respect to molecular weight and [35S]methionine tryptic peptide composition, they each differed from wt AbLV P120 in their patterns of post-translational phosphorylation. A previously described AbLV-associated protein kinase activity is shown to recognize as substrate a major tyrosine-specific acceptor site(s) contained within a single well-resolved tryptic peptide common to both AbLV P120 and P80. In vitro [gamma-32P]ATP-mediated labeling of this phosphorylation site was reduced to below detectable levels in td mutant nonproductively infected cell clones. These findings establish that the AbLV-encoded polyprotein P120 and its associated protein kinase activity are involved in AbLV tumorigenesis. Images PMID:6253663

  9. PpIX induces mitochondria-related apoptosis in murine leukemia L1210 cells.

    PubMed

    Su, Xiaomin; Chen, Yan; Wang, Xiaobing; Wang, Yuan; Wang, Pan; Li, Long; Liu, Quanhong

    2014-07-01

    Protoporphyrin IX (PpIX), a well-known sensitizer that can enhance laser light or ultrasound induced cytotoxicity in photodynamic and sonodynamic therapy. However, PpIX alone could effectively cause anti-tumor effect and the underlying mechanisms are rarely been reported. Therefore, this study was to investigate the possible mechanism by which PpIX revealed anti-proliferative effect on murine leukemia L1210 cells. The accumulation of PpIX in L1210 cells and normal peripheral blood mononuclear cells (PBMCs) was evaluated with flow cytometry. The subcellular localization of PpIX and apoptosis-inducing factor (AIF) translocation were determined by confocal microscope. The cell viability was examined by MTT assay. Annexin V-PE/7-AAD and DAPI staining were used to detect apoptotic cells. The mitochondrial membrane potential (MMP) changes were tested by rhodamine123 staining. DNA damage was measured by comet assay. PpIX preferentially accumulated in L1210 cells compared to PBMCs and PpIX mainly located in the mitochondria of L1210 cells. PpIX at a concentration of 1 µg/ml or above exerted significant anti-tumor effect and the cell viability loss presented PpIX dose-dependent manner. Typical apoptotic features such as chromatin condensation were observed by DAPI staining. Annexin V-PE/7-AAD analysis showed 5 µg/ml PpIX could induce about 24% cell apoptosis, which was inhibited by cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore. In addition, the PpIX caused MMP loss, AIF translocation to nucleus and serious DNA damage were also suppressed by CsA. The results indicate mitochondria-dependent apoptosis were involved in PpIX caused cell damage on L1210 cells.

  10. Murine model of immune-mediated rejection of the acute lymphoblastic leukemia 70Z/3.

    PubMed

    Labbe, Alain; Tran, Anne H; Paige, Christopher J

    2006-05-01

    70Z/3 is a murine pre-B cell leukemia line derived from BDF(1) mice and has been used in the study of signaling pathways in B cells. 70Z/3 cells were initially found to cause widespread disease upon injections in animals. We have isolated 70Z/3 variants divergent in their capacity to lead to morbidity after injections. One variant, 70Z/3-NL, elicits an immune response protecting the animal from tumor growth. Another variant, 70Z/3-L, does not induce an effective immune response and causes morbidity. We demonstrated that both CD4(+) and CD8(+) T cells are required for the rejection of 70Z/3-NL cells. Interestingly, the immune response generated against 70Z/3-NL cells was found to protect against a challenge with the lethal variant, 70Z/3-L. This indicates that although both lines can be recognized and killed by the immune system, only 70Z/3-NL is capable of inducing a protective response. Further observations, using subclones isolated from 70Z/3-NL, demonstrated that immune recognition of a portion of the cells was sufficient for protection. Depletion of CD4(+) and CD8(+) T cells in animals injected previously with 70Z/3-NL cells showed that T cells, and not Abs, were required for the maintenance of the protection initiated by 70Z/3-NL. We tested the capacity of 70Z/3-NL cells to treat mice challenged with 70Z/3-L. We can delay injections of 70Z/3-NL and still provide protection for the animals. We have a model of immune-mediated rejection which will allow us to dissect the requirements for the initiation of immune responses against an ALL tumor cell line.

  11. Splicing of Friend Murine Leukemia Virus env-mRNA Enhances Its Ability to Form Polysomes

    PubMed Central

    Machinaga, Akihito; Ishihara, Syuhei; Shirai, Akiko; Takase-Yoden, Sayaka

    2016-01-01

    Friend murine leukemia virus (MLV) belongs to the gamma retroviruses of the Retroviridae family. The positive-sense RNA of its genome contains a 5′ long terminal repeat (LTR), 5′ leader sequence, gag, pol, env, and 3′ LTR. Transcription from proviral DNA begins from the R region of the 5′ LTR and ends at the polyadenylation signal located at the R region of the other end of the 3′ LTR. There is a 5′ splice site in the 5′ leader sequence and a 3′ splice site at the 3′ end of the pol region. Both full-length unspliced mRNAs and a singly spliced mRNA (env-mRNA) are produced in MLV-infected cells. The MLV Env protein plays important roles both in viral adsorption to host cells and in neuropathogenic disease in MLV-infected mice and rats. Understanding the regulatory mechanisms controlling Env expression is important for determining the functions of the Env protein. We have previously shown that splicing increases env-mRNA stability and translation efficiency. Generally, mRNA polysome formation correlates with translation efficiency. Therefore, here we investigated the effects of env-mRNA splicing on polysome formation to identify mechanisms for Env up-regulation due to splicing. We performed polysome profile analyses using Env-expression plasmids producing spliced or unspliced env-mRNA and showed that the former formed polysomes more efficiently than the latter. Thus, splicing of env-mRNA facilitated polysome formation, suggesting that this contributes to up-regulation of Env expression. We replaced the env region of the expression plasmids with a luciferase (luc) gene, and found that in this case both unspliced and spliced luc-mRNA formed polysomes to a similar extent. Thus, we conclude that whether mRNA polysome formation is affected by splicing depends on the structure of gene in question. PMID:26909075

  12. Mink Cell Focus-Forming Murine Leukemia Virus Killing of Mink Cells Involves Apoptosis and Superinfection

    PubMed Central

    Yoshimura, Fayth K.; Wang, Tao; Nanua, Suparna

    2001-01-01

    Induction of apoptosis by different types of pathogenic retroviruses is an important step in disease development. We have observed that infection of thymic lymphocytes by the mink cell focus-forming murine leukemia virus (MCF MLV) during the preleukemic period resulted in an enhancement of apoptosis of these cells. To further study the ability of MCF MLVs to induce apoptosis and the role of this process in viral pathogenesis, we have developed an in vitro system of virus-induced apoptosis. MCF13 MLV infection of mink epithelial cells resulted in the production of cytopathic foci. In contrast, infection of mink cells with the 4070A amphotropic MLV did not produce any cytopathic effects. Staining of MCF13 MLV-infected cells with propidium iodide and annexin V-fluorescein isothiocyanate indicated that virus-induced cell death was due to apoptosis. At 6 days postinfection, the percentage of apoptotic MCF13 MLV-infected cells was 27% compared with 2 to 3% for mock- or amphotropic MLV-infected cells, representing a 9- to 14-fold difference. Assays for caspase-3 activation confirmed the detection by flow cytometry of apoptosis of MCF13 MLV-infected cells. Large amounts of unintegrated linear viral DNA were detectable by Southern blot analysis during the acute phase of infection, which indicated that MCF13 MLV is able to superinfect mink cells. Unintegrated viral DNA of only the linear form was detectable in thymic lymphocytes isolated from MCF13 MLV-inoculated mice during the preleukemic period. These results indicated that the ability of MCF13 MLV to induce apoptosis is correlated with its ability to superinfect cells and that this occurs as an early step in thymic lymphoma development. PMID:11390602

  13. Triptolide induced cell death through apoptosis and autophagy in murine leukemia WEHI-3 cells in vitro and promoting immune responses in WEHI-3 generated leukemia mice in vivo.

    PubMed

    Chan, Shih-Feng; Chen, Ya-Yin; Lin, Jen-Jyh; Liao, Ching-Lung; Ko, Yang-Ching; Tang, Nou-Ying; Kuo, Chao-Lin; Liu, Kuo-Ching; Chung, Jing-Gung

    2017-02-01

    Triptolide, a traditional Chinese medicine, obtained from Tripterygium wilfordii Hook F, has anti-inflammatory, antiproliferative, and proapoptotic properties. We investigated the potential efficacy of triptolide on murine leukemia by measuring the triptolide-induced cytotoxicity in murine leukemia WEHI-3 cells in vitro. Results indicated that triptolide induced cell morphological changes and induced cytotoxic effects through G0/G1 phase arrest, induction of apoptosis. Flow cytometric assays showed that triptolide increased the production of reactive oxygen species, Ca(2+) release and mitochondrial membrane potential (ΔΨm ), and activations of caspase-8, -9, and -3. Triptolide increased protein levels of Fas, Fas-L, Bax, cytochrome c, caspase-9, Endo G, Apaf-1, PARP, caspase-3 but reduced levels of AIF, ATF6α, ATF6β, and GRP78 in WEHI-3 cells. Triptolide stimulated autophagy based on an increase in acidic vacuoles, monodansylcadaverine staining for LC-3 expression and increased protein levels of ATG 5, ATG 7, and ATG 12. The in vitro data suggest that the cytotoxic effects of triptolide may involve cross-talk between cross-interaction of apoptosis and autophagy. Normal BALB/c mice were i.p. injected with WEHI-3 cells to generate leukemia and were oral treatment with triptolide at 0, 0.02, and 0.2 mg/kg for 3 weeks then animals were weighted and blood, liver, spleen samples were collected. Results indicated that triptolide did not significantly affect the weights of animal body, spleen and liver of leukemia mice, however, triptolide significant increased the cell populations of T cells (CD3), B cells (CD19), monocytes (CD11b), and macrophage (Mac-3). Furthermore, triptolide increased the phagocytosis of macrophage from peripheral blood mononuclear cells (PBMC) but not effects from peritoneum. Triptolide promoted T and B cell proliferation at 0.02 and 0.2 mg/kg treatment when cells were pretreated with Con A and LPS stimulation, respectively; however, triptolide

  14. Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. ...

  15. Androgen-independent proliferation of LNCaP prostate cancer cells infected by xenotropic murine leukemia virus-related virus

    SciTech Connect

    Kakoki, Katsura; Kamiyama, Haruka; Izumida, Mai; Yashima, Yuka; Hayashi, Hideki; Yamamoto, Naoki; Matsuyama, Toshifumi; Igawa, Tsukasa; Sakai, Hideki; Kubo, Yoshinao

    2014-04-25

    Highlights: • XMRV infection induces androgen-independent growth in LNCaP cells. • XMRV infection reduces expression of androgen receptor. • XMRV promotes appearance of androgen blocker-resistant prostate cancer cells. - Abstract: Xenotropic murine leukemia virus-related virus (XMRV) is a novel gammaretrovirus that was originally isolated from human prostate cancer. It is now believed that XMRV is not the etiologic agent of prostate cancer. An analysis of murine leukemia virus (MLV) infection in various human cell lines revealed that prostate cancer cell lines are preferentially infected by XMRV, and this suggested that XMRV infection may confer some sort of growth advantage to prostate cancer cell lines. To examine this hypothesis, androgen-dependent LNCaP cells were infected with XMRV and tested for changes in certain cell growth properties. We found that XMRV-infected LNCaP cells can proliferate in the absence of the androgen dihydrotestosterone. Moreover, androgen receptor expression is significantly reduced in XMRV-infected LNCaP cells. Such alterations were not observed in uninfected and amphotropic MLV-infected LNCaP cells. This finding explains why prostate cancer cell lines are preferentially infected with XMRV.

  16. Origin of pathogenic determinants of recombinant murine leukemia viruses: analysis of Bxv-1-related xenotropic viruses from CWD mice.

    PubMed Central

    Massey, A C; Coppola, M A; Thomas, C Y

    1990-01-01

    The acquisition of U3 region sequences derived from the endogenous xenotropic provirus Bxv-1 appears to be an important step in the generation of leukemogenic recombinant viruses in AKR, HRS, C58, and some CWD mice. We report here that each of three CWD lymphomas produced infectious xenotropic murine leukemia virus related to Bxv-1. In Southern blot experiments, these proviruses hybridized to probes that were specific for the xenotropic envelope and Bxv-1 U3 region sequences. Nucleotide sequence analysis of a cloned CWD xenotropic provirus, CWM-S-5X, revealed that the envelope gene was closely related to but distinct from those of other known xenotropic viruses. In addition, the U3 region of CWM-S-5X contained a viral enhancer sequence that was identical to that found in MCF 247, a recombinant AKR virus that is thought to contain the Bxv-1 enhancer. Finally, restriction enzyme sites in the CWM-S-5X provirus were analogous to those reported within Bxv-1. These results establish that the virus progeny of Bxv-1 have the potential to donate pathogenic enhancer sequences to recombinant polytropic murine leukemia viruses. Interestingly, the three CWD polytropic viruses that were isolated from the same tumor cells that produced the Bxv-1-like viruses had not incorporated Bxv-1 sequences into the U3 region. Images PMID:2170683

  17. Gene expression profiling of microglia infected by a highly neurovirulent murine leukemia virus: implications for neuropathogenesis

    PubMed Central

    Dimcheff, Derek E; Volkert, L Gwenn; Li, Ying; DeLucia, Angelo L; Lynch, William P

    2006-01-01

    Background Certain murine leukemia viruses (MLVs) are capable of inducing progressive spongiform motor neuron disease in susceptible mice upon infection of the central nervous system (CNS). The major CNS parenchymal target of these neurovirulent retroviruses (NVs) are the microglia, whose infection is largely coincident with neuropathological changes. Despite this close association, the role of microglial infection in disease induction is still unknown. In this paper, we investigate the interaction of the highly virulent MLV, FrCasE, with microglia ex vivo to evaluate whether infection induces specific changes that could account for neurodegeneration. Specifically, we compared microglia infected with FrCasE, a related non-neurovirulent virus (NN) F43/Fr57E, or mock-infected, both at a basic virological level, and at the level of cellular gene expression using quantitative real time RT-PCR (qRT-PCR) and Afffymetrix 430A mouse gene chips. Results Basic virological comparison of NN, NV, and mock-infected microglia in culture did not reveal differences in virus expression that provided insight into neuropathogenesis. Therefore, microglial analysis was extended to ER stress gene induction based on previous experiments demonstrating ER stress induction in NV-infected mouse brains and cultured fibroblasts. Analysis of message levels for the ER stress genes BiP (grp78), CHOP (Gadd153), calreticulin, and grp58 in cultured microglia, and BiP and CHOP in microglia enriched fractions from infected mouse brains, indicated that FrCasE infection did not induce these ER stress genes either in vitro or in vivo. To broadly identify physiological changes resulting from NV infection of microglia in vitro, we undertook a gene array screen of more than 14,000 well-characterized murine genes and expressed sequence tags (ESTs). This analysis revealed only a small set of gene expression changes between infected and uninfected cells (<18). Remarkably, gene array comparison of NN- and NV

  18. MN1–Fli1 oncofusion transforms murine hematopoietic progenitor cells into acute megakaryoblastic leukemia cells

    PubMed Central

    Wenge, D V; Felipe-Fumero, E; Angenendt, L; Schliemann, C; Schmidt, E; Schmidt, L H; Thiede, C; Ehninger, G; Berdel, W E; Arteaga, M-F; Mikesch, J-H

    2015-01-01

    Long-term outcome of acute megakaryoblastic leukemia (AMKL) patients without Down's syndrome remains poor. Founding mutations and chimeric oncogenes characterize various AMKL subtypes. However, for around one third of all cases the underlying mechanisms of AMKL leukemogenesis are still largely unknown. Recently, an in-frame fusion of meningeoma 1–friend leukemia virus integration 1 (MN1–Fli1) gene was detected in a child with AMKL. We intended to investigate the potential role of this oncofusion in leukemogenesis of acute myeloid leukemia. Strikingly, expression of MN1–Fli1 in murine hematopoietic progenitor cells was sufficient to induce leukemic transformation generating immature myeloid cells with cytomorphology and expression of surface markers typical for AMKL. Systematic structure function analyses revealed FLS and 3′ETS domains of Fli1 as decisive domains for the AMKL phenotype. Our data highlight an important role of MN1–Fli1 in AMKL leukemogenesis and provide a basis for research assessing the value of this oncofusion as a future diagnostic marker and/or therapeutic target in AMKL patients. PMID:26690545

  19. Discovery of 3H-Benzo[4,5]thieno[3,2-d]pyrimidin-4-ones as Potent, Highly Selective, and Orally Bioavailable Inhibitors of the Human Protooncogene Proviral Insertion Site in Moloney Murine Leukemia Virus (PIM) Kinases

    SciTech Connect

    Tao, Zhi-Fu; Hasvold, Lisa A.; Leverson, Joel D.; Han, Edward K.; Guan, Ran; Johnson, Eric F.; Stoll, Vincent S.; Stewart, Kent D.; Stamper, Geoff; Soni, Nirupama; Bouska, Jennifer J.; Luo, Yan; Sowin, Thomas J.; Lin, Nan-Horng; Giranda, Vincent S.; Rosenberg, Saul H.; Penning, Thomas D.

    2010-02-19

    Pim-1, Pim-2, and Pim-3 are a family of serine/threonine kinases which have been found to be overexpressed in a variety of hematopoietic malignancies and solid tumors. Benzothienopyrimidinones were discovered as a novel class of Pim inhibitors that potently inhibit all three Pim kinases with subnanomolar to low single-digit nanomolar K{sub i} values and exhibit excellent selectivity against a panel of diverse kinases. Protein crystal structures of the bound Pim-1 complexes of benzothienopyrimidinones 3b (PDB code 3JYA), 6e (PDB code 3JYO), and 12b (PDB code 3JXW) were determined and used to guide SAR studies. Multiple compounds exhibited potent antiproliferative activity in K562 and MV4-11 cells with submicromolar EC{sub 50} values. For example, compound 14j inhibited the growth of K562 cells with an EC{sub 50} value of 1.7 {micro}M and showed K{sub i} values of 2, 3, and 0.5 nM against Pim-1, Pim-2, and Pim-3, respectively. These novel Pim kinase inhibitors efficiently interrupted the phosphorylation of Bad in both K562 and LnCaP-Bad cell lines, indicating that their potent biological activities are mechanism-based. The pharmacokinetics of 14j was studied in CD-1 mice and shown to exhibit bioavailability of 76% after oral dosing. ADME profiling of 14j suggested a long half-life in both human and mouse liver microsomes, good permeability, modest protein binding, and no CYP inhibition below 20 {micro}M concentration.

  20. Expression of IMP1 enhances production of murine leukemia virus vector by facilitating viral genomic RNA packaging.

    PubMed

    Mai, Yun; Gao, Guangxia

    2010-12-29

    Murine leukemia virus (MLV)-based retroviral vector is widely used for gene transfer. Efficient packaging of the genomic RNA is critical for production of high-titer virus. Here, we report that expression of the insulin-like growth factor II mRNA binding protein 1 (IMP1) enhanced the production of infectious MLV vector. Overexpression of IMP1 increased the stability of viral genomic RNA in virus producer cells and packaging of the RNA into progeny virus in a dose-dependent manner. Downregulation of IMP1 in virus producer cells resulted in reduced production of the retroviral vector. These results indicate that IMP1 plays a role in regulating the packaging of MLV genomic RNA and can be used for improving production of retroviral vectors.

  1. A locus that enhances the induction of endogenous ecotropic murine leukemia viruses is distinct from genome-length ecotropic proviruses.

    PubMed Central

    Horowitz, J M; Risser, R

    1982-01-01

    The segregation of genes that enhance the induction of ecotropic murine leukemia viruses (In loci) has been compared with the segregation of ecotropic-specific nucleotide sequences in 12 low-leukemic mouse strains and 18 recombinant inbred strains. Endogenous ecotropic viruses of these strains are of genome length and structurally similar to AKR ecotropic proviruses. Low-leukemic strains of related pedigree contain ecotropic proviruses at common integration sites. Loci previously identified which enhance induction of ecotropic viruses (In genes) were correlated with the inheritance of ecotropic viral sequences in inbred low-leukemic mouse strains and in CXB recombinant inbred mouse strains. However, four BXH recombinant inbred strains were observed to possess an In gene(s) yet lack the probed envelope gene region for the corresponding endogenous ecotropic virus. These observations indicate that at least one gene that enhances ecotropic virus expression in vitro is encoded by DNA sequences outside ecotropic proviruses or by subgenomic viral sequences. Images PMID:6294342

  2. Contrasting roles of leukemia inhibitory factor in murine bone development and remodeling involve region-specific changes in vascularization.

    PubMed

    Poulton, Ingrid J; McGregor, Narelle E; Pompolo, Sueli; Walker, Emma C; Sims, Natalie A

    2012-03-01

    We describe here distinct functions of leukemia inhibitory factor (LIF) in bone development/growth and adult skeletal homeostasis. In the growth plate and developing neonate bones, LIF deficiency enhanced vascular endothelial growth factor (VEGF) levels, enlarged blood vessel formation, and increased the formation of "giant" osteoclasts/chondroclasts that rapidly destroyed the mineralized regions of the growth plate and developing neonatal bone. Below this region, osteoblasts formed large quantities of woven bone. In contrast, in adult bone undergoing remodeling osteoclast formation was unaffected by LIF deficiency, whereas osteoblast formation and function were both significantly impaired, resulting in osteopenia. Consistent with LIF promoting osteoblast commitment, enhanced marrow adipocyte formation was also observed in adult LIF null mice, and adipocytic differentiation of murine stromal cells was delayed by LIF treatment. LIF, therefore, controls vascular size and osteoclast differentiation during the transition of cartilage to bone, whereas an anatomically separate LIF-dependent pathway regulates osteoblast and adipocyte commitment in bone remodeling.

  3. No Evidence for Xenotropic Murine Leukemia-Related Virus Infection in Sweden Using Internally Controlled Multiepitope Suspension Array Serology

    PubMed Central

    Blomberg, Fredrik; Sjösten, Anna; Sheikholvaezin, Ali; Bölin-Wiener, Agnes; Elfaitouri, Amal; Hessel, Sanna; Gottfries, Carl-Gerhard; Zachrisson, Olof; Öhrmalm, Christina; Jobs, Magnus; Pipkorn, Rüdiger

    2012-01-01

    Many syndromes have a large number of differential diagnoses, a situation which calls for multiplex diagnostic systems. Myalgic encephalomyelitis (ME), also named chronic fatigue syndrome (CFS), is a common disease of unknown etiology. A mouse retrovirus, xenotropic murine leukemia-related virus (XMRV), was found in ME/CFS patients and blood donors, but this was not corroborated. However, the paucity of serological investigations on XMRV in humans prompted us to develop a serological assay which cover many aspects of XMRV antigenicity. It is a novel suspension array method, using a multiplex IgG assay with nine recombinant proteins from the env and gag genes of XMRV and 38 peptides based on known epitopes of vertebrate gammaretroviruses. IgG antibodies were sought in 520 blood donors and 85 ME/CFS patients and in positive- and negative-control sera from animals. We found no differences in seroreactivity between blood donors and ME/CFS patients for any of the antigens. This did not support an association between ME/CFS and XMRV infection. The multiplex serological system had several advantages: (i) biotinylated protein G allowed us to run both human and animal sera, which is essential because of a lack of XMRV-positive humans; (ii) a novel quality control was a pan-peptide positive-control rabbit serum; and (iii) synthetic XMRV Gag peptides with degenerate positions covering most of the variation of murine leukemia-like viruses did not give higher background than nondegenerate analogs. The principle may be used for creation of variant tolerant peptide serologies. Thus, our system allows rational large-scale serological assays with built-in quality control. PMID:22787191

  4. In vitro proteolytic cleavage of Gazdar murine sarcoma virus p65gag.

    PubMed

    Maxwell, S; Arlinghaus, R B

    1981-09-01

    Moloney murine leukemia virus, disrupted in concentrations of 0.1 to 0.5% Nonidet P-40, catalyzed the cleavage of p65, the gag gene polyprotein of the Gazdar strain of murine sarcoma virus, into polypeptides with sizes and antigenic determinants of murine leukemia virus-specified p30, p15, pp12, and p10. Cleavage performed in the presence of 0.15% Nonidet P-40 in water yielded polypeptides of approximately 40,000 (P40) and 25,000 (P25) Mr. In vitro cleavage performed in a buffered solution containing dithiothreitol in addition to 0.1% Nonidet P-40 allowed the efficient processing of P40 to p30 and a band migrating with p10. Immunoprecipitation with monospecific sera indicated that P40 contained p30 and p10, whereas P25 contained p15 and pp12 determinants. P40 and P25 are similar in size and antigenic properties to Pr40gag and Pr25gag observed in infected cells (Naso et al, J. Virol. 32:187-198, 1979).

  5. Solanum lyratum Extracts Induce Extrinsic and Intrinsic Pathways of Apoptosis in WEHI-3 Murine Leukemia Cells and Inhibit Allograft Tumor.

    PubMed

    Yang, Jai-Sing; Wu, Chia-Chun; Kuo, Chao-Lin; Lan, Yu-Hsuan; Yeh, Chin-Chung; Yu, Chien-Chih; Lien, Jin-Cherng; Hsu, Yuan-Man; Kuo, Wei-Wen; Wood, W Gibson; Tsuzuki, Minoru; Chung, Jing-Gung

    2012-01-01

    We investigated the molecular mechanisms of cell cycle arrest and apoptotic death induced by Solanum lyratum extracts (SLE) or diosgenin in WEHI-3 murine leukemia cells in vitro and antitumor activity in vivo. Diosgenin is one of the components of SLE. Our study showed that SLE and diosgenin decreased the viable WEHI-3 cells and induced G(0)/G(1) phase arrest and apoptosis in concentration- or time-dependent manners. Both reagents increased the levels of ROS production and decreased the mitochondrial membrane potential (ΔΨ(m)). SLE- and diosgenin-triggered apoptosis is mediated through modulating the extrinsic and intrinsic signaling pathways. Intriguingly, the p53 inhibitor (pifithrin-α), anti-Fas ligand (FasL) mAb, and specific inhibitors of caspase-8 (z-IETD-fmk), caspase-9 (z-LEHD-fmk), and caspase-3 (z-DEVD-fmk) blocked SLE- and diosgenin-reduced cell viability of WEHI-3 cells. The in vivo study demonstrated that SLE has marked antitumor efficacy against tumors in the WEHI-3 cell allograft model. In conclusion, SLE- and diosgenin-induced G(0)/G(1) phase arrest and triggered extrinsic and intrinsic apoptotic pathways via p53 activation in WEHI-3 cells. SLE also exhibited antitumor activity in vivo. Our findings showed that SLE may be potentially efficacious in the treatment of leukemia in the future.

  6. Solanum lyratum Extracts Induce Extrinsic and Intrinsic Pathways of Apoptosis in WEHI-3 Murine Leukemia Cells and Inhibit Allograft Tumor

    PubMed Central

    Yang, Jai-Sing; Wu, Chia-Chun; Kuo, Chao-Lin; Lan, Yu-Hsuan; Yeh, Chin-Chung; Yu, Chien-Chih; Lien, Jin-Cherng; Hsu, Yuan-Man; Kuo, Wei-Wen; Wood, W. Gibson; Tsuzuki, Minoru; Chung, Jing-Gung

    2012-01-01

    We investigated the molecular mechanisms of cell cycle arrest and apoptotic death induced by Solanum lyratum extracts (SLE) or diosgenin in WEHI-3 murine leukemia cells in vitro and antitumor activity in vivo. Diosgenin is one of the components of SLE. Our study showed that SLE and diosgenin decreased the viable WEHI-3 cells and induced G0/G1 phase arrest and apoptosis in concentration- or time-dependent manners. Both reagents increased the levels of ROS production and decreased the mitochondrial membrane potential (ΔΨm). SLE- and diosgenin-triggered apoptosis is mediated through modulating the extrinsic and intrinsic signaling pathways. Intriguingly, the p53 inhibitor (pifithrin-α), anti-Fas ligand (FasL) mAb, and specific inhibitors of caspase-8 (z-IETD-fmk), caspase-9 (z-LEHD-fmk), and caspase-3 (z-DEVD-fmk) blocked SLE- and diosgenin-reduced cell viability of WEHI-3 cells. The in vivo study demonstrated that SLE has marked antitumor efficacy against tumors in the WEHI-3 cell allograft model. In conclusion, SLE- and diosgenin-induced G0/G1 phase arrest and triggered extrinsic and intrinsic apoptotic pathways via p53 activation in WEHI-3 cells. SLE also exhibited antitumor activity in vivo. Our findings showed that SLE may be potentially efficacious in the treatment of leukemia in the future. PMID:22611426

  7. Selective transduction of murine myelomonocytic leukemia cells (WEHI-3B) with regular and RGD-adenoviral vectors.

    PubMed

    García-Castro, J; Segovia, J C; García-Sánchez, F; Lillo, R; Gómez-Navarro, J; Curiel, D T; Bueren, J A

    2001-01-01

    On the basis of the susceptibility of normal myelomonocytic cells to adenoviral vectors, we have studied the possibility of selectively transducing myelomonocytic murine leukemic cells (WEHI-3B) with regular (Reg-Ad) and genetically modified (RGD-Ad) adenoviral vectors. An 8-h incubation of WEHI-3B cells with 100 pfu of Reg-Ad vectors/cell resulted in the whole population becoming positive for transgene expression. Under identical conditions of infection, 20-30% of mouse bone marrow (BM) cells were positive for the transgene. When RGD-Ad vectors were used, a brief exposure (10 min) of WEHI-3B cells to 150 pfu of the virus/cell was enough for 100% of the leukemia cells to become positive for the marker transgene (EGFP). Under these conditions, only 15-20% of BM cells and of primitive hematopoietic progenitors (Lin(-)Sca-1(+) cells) became EGFP(+), indicating an improved selectivity of the vectors for the leukemic cells. The incubation of WEHI-3B but not normal BM cells with soluble fiber protein (FP) inhibited the infection with Reg-Ad. The use of the RGD-Ad bypassed the FP-CAR interaction required for the transduction of WEHI-3B cells with Reg-Ad, suggesting that the abrogation of this requirement accounts for the improved infectivity of these leukemic cells and for the selectivity of RGD-Ad in targeting WEHI-3B leukemia cells.

  8. TUMOR INDUCTION BY MURINE SARCOMA VIRUS IN AKR AND C58 MICE

    PubMed Central

    Chieco-Bianchi, Luigi; Colombatti, Alfonso; Collavo, Dino; Sendo, Fujiro; Aoki, Tadao; Fischinger, Peter J.

    1974-01-01

    Adult AKR and C58 mice injected intramuscularly with murine sarcoma virus, Moloney isolate (M-MSV), developed high incidence of nonregressing local tumors. Histologically, these tumors revealed the typical pleomorphism of M-MSV sarcomas; in some cases, however, neoplastic tissue showed a nodular or diffuse growth of monomorphic myoblastlike cells, reminiscent of clonal aggregates. No depression of immune reactivity was found in M-MSV-injected mice as evaluated by direct hemolytic plaque-forming cells against SRBC and by virus-neutralizing antibody production. The MSV recovered from the induced tumors proved to be, by neutralization assay, a Gross (G)-MSV pseudotype. Moreover, tumor cell suspensions absorbed out cytotoxic antibody directed against G-cell surface antigens. Therefore, the conclusion was drawn that MSV with envelope characteristics of endogenous G leukemia virus had formed in vivo through a phenotypic mixing phenomenon. The failure of tumors to regress has been interpreted as mainly due to the partial unresponsiveness of host immune reactivity towards G-MuLV specified antigens. Since MSV-tumors arose in AKR mice after a very long latent period, the possibility was considered that this relative resistance might depend on immunologic mechanisms. In fact, M-MSV-injected AKR mice immunodepressed by goat antimouse lymphocyte serum or rendered partially tolerant by neonatal M-MuLV inoculation developed sarcomas with higher incidence and with a shorter latency. Furthermore, the MSV recovered from these early tumors proved to be the original Moloney pseudotype. PMID:4608945

  9. Anti-CD45 radioimmunotherapy using (211)At with bone marrow transplantation prolongs survival in a disseminated murine leukemia model.

    PubMed

    Orozco, Johnnie J; Bäck, Tom; Kenoyer, Aimee; Balkin, Ethan R; Hamlin, Donald K; Wilbur, D Scott; Fisher, Darrell R; Frayo, Shani L; Hylarides, Mark D; Green, Damian J; Gopal, Ajay K; Press, Oliver W; Pagel, John M

    2013-05-02

    Despite aggressive chemotherapy combined with hematopoietic stem cell transplantation (HSCT), many patients with acute myeloid leukemia (AML) relapse. Radioimmunotherapy (RIT) using monoclonal antibodies labeled with β-emitting radionuclides has been explored to reduce relapse. β emitters are limited by lower energies and nonspecific cytotoxicity from longer path lengths compared with α emitters such as (211)At, which has a higher energy profile and shorter path length. We evaluated the efficacy and toxicity of anti-CD45 RIT using (211)At in a disseminated murine AML model. Biodistribution studies in leukemic SJL/J mice showed excellent localization of (211)At-anti-murine CD45 mAb (30F11) to marrow and spleen within 24 hours (18% and 79% injected dose per gram of tissue [ID/g], respectively), with lower kidney and lung uptake (8.4% and 14% ID/g, respectively). In syngeneic HSCT studies, (211)At-B10-30F11 RIT improved the median survival of leukemic mice in a dose-dependent fashion (123, 101, 61, and 37 days given 24, 20, 12, and 0 µCi, respectively). This approach had minimal toxicity with nadir white blood cell counts >2.7 K/µL 2 weeks after HSCT and recovery by 4 weeks. These data suggest that (211)At-anti-CD45 RIT in conjunction with HSCT may be a promising therapeutic option for AML.

  10. Anti-CD45 radioimmunotherapy using 211At with bone marrow transplantation prolongs survival in a disseminated murine leukemia model

    PubMed Central

    Orozco, Johnnie J.; Bäck, Tom; Kenoyer, Aimee; Balkin, Ethan R.; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.; Frayo, Shani L.; Hylarides, Mark D.; Green, Damian J.; Gopal, Ajay K.; Press, Oliver W.

    2013-01-01

    Despite aggressive chemotherapy combined with hematopoietic stem cell transplantation (HSCT), many patients with acute myeloid leukemia (AML) relapse. Radioimmunotherapy (RIT) using monoclonal antibodies labeled with β-emitting radionuclides has been explored to reduce relapse. β emitters are limited by lower energies and nonspecific cytotoxicity from longer path lengths compared with α emitters such as 211At, which has a higher energy profile and shorter path length. We evaluated the efficacy and toxicity of anti-CD45 RIT using 211At in a disseminated murine AML model. Biodistribution studies in leukemic SJL/J mice showed excellent localization of 211At-anti-murine CD45 mAb (30F11) to marrow and spleen within 24 hours (18% and 79% injected dose per gram of tissue [ID/g], respectively), with lower kidney and lung uptake (8.4% and 14% ID/g, respectively). In syngeneic HSCT studies, 211At-B10-30F11 RIT improved the median survival of leukemic mice in a dose-dependent fashion (123, 101, 61, and 37 days given 24, 20, 12, and 0 µCi, respectively). This approach had minimal toxicity with nadir white blood cell counts >2.7 K/µL 2 weeks after HSCT and recovery by 4 weeks. These data suggest that 211At-anti-CD45 RIT in conjunction with HSCT may be a promising therapeutic option for AML. PMID:23471305

  11. Reversal of Fv-1 host range by in vitro restriction endonuclease fragment exchange between molecular clones of N-tropic and B-tropic murine leukemia virus genomes

    SciTech Connect

    Boone, L.R.; Myer, F.E.; Yang, D.M.; Ou, C.Y.; Koh, C.K.; Roberson, L.E.; Tennant, R.W.; Yang, W.K.

    1983-10-01

    Unintegrated viral DNA of the BALB/c endogenous N-tropic and B-tropic murine leukemia retroviruses and invitro passaged N-tropic Gross (passage A) murine leukemia retroviruses were molecularly cloned. Recombinant genomes were constructed in vitro by exchanging homologous restriction enzyme fragments from N- or B-tropic parents and subsequent recloning. Infectious virus was recovered after transfection of these recombinant genomes into NIH-3T3 cells and cocultivation with the Fv-1 nonrestrictive SC-1 cells. XC plaque assays of recombinant virus progeny on Fv-1/sup n/ and Fv-1/sup b/ cells indicated the the Fv-1 host range was determined by sequences located between the BamHI site in the p30 region of the gag gene (1.6 kilobase pairs from the left end of the map) and the HindIII site located in the pol gene (2.9 kilobase pairs from the left end of the map.

  12. Reversal of Fv-1 host range by in vitro restriction endonuclease fragment exchange between molecular clones of N-tropic and B-tropic murine leukemia virus genomes

    SciTech Connect

    Boone, L.R.; Myer, F.E.; Yang, D.M.; Ou, C.Y.; Koh, C.K.; Roberson, L.E.; Tennant, R.W.; Yang, W.K.

    1983-10-01

    The authors molecularly cloned unintegrated viral DNA of the BALB/c endogenous N-tropic and B-tropic murine leukemia retroviruses and in vitro passage N-tropic Gross (passage A) murine leukemia retroviruses. Recombinant genomes were constructed in vitro by exchanging homologous restriction enzyme fragments from N- or B-tropic parents and subsequent recloning. Infectious virus was recovered after transfection of these recombinant genomes into NIH-3T3 cells and cocultivation with the Fv-1 nonrestrictive SC-1 cells. XC plaque assays of recombinant virus progeny on Fv-1/sup n/ and Fv-1/sup b/ cells indicated that the Fv-1 host range was determined by sequences located between the BamHI site in the p30 region of the gag gene (1.6 kilobase pairs from the left end of the map) and the HindIII site located in pol gene (2.9 kilobase pairs from the left end of the map).

  13. Long terminal repeat of murine retroviral DNAs: sequence analysis, host-proviral junctions, and preintegration site.

    PubMed Central

    Van Beveren, C; Rands, E; Chattopadhyay, S K; Lowy, D R; Verma, I M

    1982-01-01

    The nucleotide sequence of the long terminal repeat (LTR) of three murine retroviral DNAs has been determined. The data indicate that the U5 region (sequences originating from the 5' end of the genome) of various LTRs is more conserved than the U3 region (sequences from the 3' end of the genome). The location and sequence of the control elements such as the 5' cap, "TATA-like" sequences, "CCAAT-box," and presumptive polyadenylic acid addition signal AATAAA in the various LTRs are nearly identical. Some murine retroviral DNAs contain a duplication of sequences within the LTR ranging in size from 58 to 100 base pairs. A variant of molecularly cloned Moloney murine sarcoma virus DNA in which one of the two LTRs integrated into the viral DNA was also analyzed. A 4-base-pair duplication was generated at the site of integration of LTR in the viral DNA. The host-viral junction of two molecularly cloned AKR-murine leukemia virus DNAs (clones 623 and 614) was determined. In the case of AKR-623 DNA, a 3- or 4-base-pair direct repeat of cellular sequences flanking the viral DNA was observed. However, AKR-614 DNA contained a 5-base-pair repeat of cellular sequences. The nucleotide sequence of the preintegration site of AKR-623 DNA revealed that the cellular sequences duplicated during integration are present only once. Finally, a striking homology between the sequences flanking the preintegration site and viral LTRs was observed. Images PMID:6281466

  14. The leukemia-associated gene Mllt1/ENL: characterization of a murine homolog and demonstration of an essential role in embryonic development.

    PubMed

    Doty, Raymond T; Vanasse, Gary J; Disteche, Christine M; Willerford, Dennis M

    2002-01-01

    MLLT1 (ENL/LTG19) is one of a number of fusion gene partners with the MLL oncogene involved in 11q23 translocations in human leukemia and encodes a transcriptional regulator of unknown function. Leukemias bearing MLL translocations may be myeloid or lymphoid or bear mixed lineage properties; however, those bearing MLL/MLLT1 translocations are predominantly lymphoid, suggesting that MLLT1 may influence the leukemic phenotype. The murine homolog Mllt1 exhibits 86% amino acid sequence identity with the human gene and is broadly expressed in murine tissues and cell lines, with the exception of liver and myeloid cell lines. We have mapped Mllt1 to mouse chromosome 17 band E2 using FISH analysis. The genomic structure and 5' regulatory sequence of Mllt1 are highly conserved between mouse and human. There is also conservation of the genomic structure, but not the promoter, between MLLT1 and MLLT3/AF9, a homologous gene that is also an MLL translocation partner in human leukemias with a predominant myeloid phenotype. Targeted disruption of Mllt1 in mice leads to embryonic lethality prior to 8.5 dpc. These studies indicate that MLLT1 is involved in essential developmental processes and suggest that expression patterns of MLL fusion partners may influence the lineage of MLL-associated leukemias.

  15. CD8+ T cells activated during the course of murine acute myelogenous leukemia elicit therapeutic responses to late B7 vaccines after cytoreductive treatment.

    PubMed

    Dunussi-Joannopoulos, K; Krenger, W; Weinstein, H J; Ferrara, J L; Croop, J M

    1997-04-15

    We have previously shown in a murine acute myelogenous leukemia (AML) model that leukemic mice can be cured with a B7 vaccine if immunized early in the disease and that CD8+ T cells are necessary for tumor rejection. However, when B7 vaccine is administered 2 weeks after leukemia inoculation, the effect is only prolonged survival, ending in death virtually of all the mice. To distinguish between tumor kinetics and tumor-induced immunosuppression as potential mechanisms eliminating the therapeutic potential of late B7 vaccines, we performed in vitro T-cell studies during leukemia progression and in vivo studies on the clinical outcome of late B7 vaccines in combination with prior cytoreductive chemotherapy. Our results show that CD8+ T cells from leukemic mice 1 and 2 weeks after leukemia inoculation proliferate more vigorously in response to in vitro activation than cells from normal mice and produce Th1-type cytokines interleukin-2 and interferon-gamma. Cytotoxic T lymphocyte (CTL) assays demonstrate that cells from week-2 vaccinated mice (which succumb to their leukemia), surprisingly develop a stronger CTL activity than cells from week-1 vaccinated mice (which reject their leukemia). Finally, the combination of late chemotherapy and late B7 vaccine administration can cure only 20% of leukemic mice, whereas early chemotherapy and the same late B7 vaccine administration cure 100% of leukemic mice. These results demonstrate that in murine AML tumor growth does not induce T-cell anergy or a Th2 cytokine profile and suggest that tumor growth is most likely to be the limiting factor in the curative potential of late B7 vaccines.

  16. Prevalence of Abelson murine leukemia viral oncogene homolog-breakpoint cluster region fusions and correlation with peripheral blood parameters in chronic myelogenous leukemia patients in Lorestan Province, Iran

    PubMed Central

    Kiani, Ali Asghar; Shahsavar, Farhad; Gorji, Mojtaba; Ahmadi, Kolsoum; Nazarabad, Vahideh Heydari; Bahmani, Banafsheh

    2016-01-01

    Context: Chronic myelogenous leukemia (CML) is a chronic malignancy of myeloid linage associated with a significant increase in granulocytes in bone marrow and peripheral blood. CML diagnosis is based on detection of Philadelphia chromosome and “Abelson murine leukemia viral oncogene homolog” (ABL)-“breakpoint cluster region protein” fusions (ABL-BCR fusions). Aims: In this study, patients with CML morphology were studied according to ABL-BCR fusions and the relationship between the fusions and peripheral blood cell changes was examined. Materials and Methods: All patients suspected to chronic myeloproliferative disorders in Lorestan Province visiting subspecialist hematology clinics who were confirmed by oncologist were studied over a period of 5 years. After completing basic data questionnaire, blood samples were obtained with informed consent from the patients. Blood cell count and morphology were investigated and RNA was extracted from blood samples. cDNA was synthesized from RNA and ABL-BCR fusions including b3a2 and b2a2 (protein 210 kd or p210), e1a2 (protein 190 kdor p190), and e19a2 (protein 230 kdor p230) were studied by multiplex reverse transcription polymerase chain reaction method. Coexistence of e1a2 and b2a2 (p210/p190) fusions was also studied. The prevalence of mutations and their correlation with the blood parameters were statistically analyzed. Results: Of 58 patients positive for ABL-BCR fusion, 18 (30.5%) had b2a2 fusion, 37 (62.71%) had b3a2 fusion and three (3.08%) had e1a2 fusion. Coexistence of e1a2 and b2a2 (p210/p190) was not observed. There was no significant correlation between ABL-BCR fusions and white blood cell count, platelet count, and hemoglobin concentration. Conclusions: The ABL-BCR fusions in Lorestan Province were similar to other studies in Iran, and b3a2 fusion had the highest prevalence in the studied patients studied. PMID:27857896

  17. Cell Surface Antigen Induced by Friend Murine Leukemia Virus Is also in the Virion

    PubMed Central

    Friedman, Maureen; Lilly, Frank; Nathenson, Stanley G.

    1974-01-01

    Intact particles of Friend leukemia virus derived from infectious mouse serum absorb only trace amounts of cytotoxic anti-FMR antibodies, but physical disruption of the virions by freezing and thawing, by ether extraction or by detergent treatment releases large amounts of FMR antigenic activity. Thus this antigen, previously considered to occur mainly as a neo-antigen on the surfaces of virus-infected cells and as a soluble substance in the serum of infected mice, may be primarily a virion component. PMID:4431079

  18. Pbx3 and Meis1 cooperate through multiple mechanisms to support Hox-induced murine leukemia

    PubMed Central

    Garcia-Cuellar, Maria-Paz; Steger, Julia; Füller, Elisa; Hetzner, Katrin; Slany, Robert K.

    2015-01-01

    Hox homeobox transcription factors drive leukemogenesis efficiently only in the presence of Meis or Pbx proteins. Here we show that Pbx3 and Meis1 need to dimerize to support Hox-induced leukemia and we analyze the molecular details of this cooperation. In the absence of Pbx3, Meis1 was highly unstable. As shown by a deletion analysis Meis1 degradation was contingent on a motif coinciding with the Pbx-binding domain. Either deletion of this sequence or binding to Pbx3 prolonged the half-life of Meis1 by preventing its ubiquitination. Meis1 break-down could also be blocked by inhibition of the ubiquitin proteasome system, indicating tight post-transcriptional control. In addition, Meis1 and Pbx3 cooperated genetically as overexpression of Pbx3 induced endogenous Meis1 transcription. These functional interactions translated into in vivo activity. Blocking Meis1/Pbx3 dimerization abrogated the ability to enhance proliferation and colony-forming cell numbers in primary cells transformed by Hoxa9. Furthermore, expression of Meis1 target genes Flt3 and Trib2 was dependent on Pbx3/Meis1 dimerization. This correlated with the requirement of Meis1 to bind Pbx3 in order to form high affinity DNA/Hoxa9/Meis1/Pbx3 complexes in vitro. Finally, kinetics and severity of disease in transplantation assays indicated that Pbx3/Meis1 dimers are rate-limiting factors for Hoxa9-induced leukemia. PMID:25911551

  19. Effect of fossil diatoms on the growth of two syngeneic murine leukemias

    NASA Astrophysics Data System (ADS)

    Bustuoabad, Oscar D.; Mayer, Alejandro M. S.

    1984-12-01

    The effect of micronized frustules of fossil diatoms (DS) on tumor growth and survival of mice receiving an ip inoculations of either a spontaneous lymphoblastic leukemia (LB) or P-388 lymphocytic leukemia (P-388) was investigated. A multi-dose study was designed, mice receiving 1000, 100, 10 and 1 μg of a suspension of DS, either ip or sc on day 1, 4 and 9 after tumor inoculation. With LB the best results were observed when DS were inoculated by the ip route, no effect being observed with the sc route. The best therapeutic effect resulted with 1 μg DS: 33% of the mice were alive 24 days after tumor inoculation, when all the controls had died. With P-388, only a temporary effect with the 10 μg DS dose was observed. In no case was it possible to prolong survival. It is concluded that at low doses of DS therapeutic effect is greatest, while toxicity due to SiO2 is greatly reduced.

  20. Chromatin states shape insertion profiles of the piggyBac, Tol2 and Sleeping Beauty transposons and murine leukemia virus

    PubMed Central

    Yoshida, Junko; Akagi, Keiko; Misawa, Ryo; Kokubu, Chikara; Takeda, Junji; Horie, Kyoji

    2017-01-01

    DNA transposons and retroviruses are versatile tools in functional genomics and gene therapy. To facilitate their application, we conducted a genome-wide insertion site profiling of the piggyBac (PB), Tol2 and Sleeping Beauty (SB) transposons and the murine leukemia virus (MLV) in mouse embryonic stem cells (ESCs). PB and MLV preferred highly expressed genes, whereas Tol2 and SB preferred weakly expressed genes. However, correlations with DNase I hypersensitive sites were different for all vectors, indicating that chromatin accessibility is not the sole determinant. Therefore, we analysed various chromatin states. PB and MLV highly correlated with Cohesin, Mediator and ESC-specific transcription factors. Notably, CTCF sites were correlated with PB but not with MLV, suggesting MLV prefers smaller promoter–enhancer loops, whereas PB insertion encompasses larger chromatin loops termed topologically associating domains. Tol2 also correlated with Cohesin and CTCF. However, correlations with ESC-specific transcription factors were weaker, suggesting that Tol2 prefers transcriptionally weak chromatin loops. Consistently, Tol2 insertions were associated with bivalent histone modifications characteristic of silent and inducible loci. SB showed minimum preference to all chromatin states, suggesting the least adverse effect on adjacent genes. These results will be useful for vector selection for various applications. PMID:28252665

  1. Crystal structures of the reverse transcriptase-associated ribonuclease H domain of xenotropic murine leukemia-virus related virus

    SciTech Connect

    Zhou, Dongwen; Chung, Suhman; Miller, Maria; Le Grice, Stuart F.J.; Wlodawer, Alexander

    2012-06-19

    The ribonuclease H (RNase H) domain of retroviral reverse transcriptase (RT) plays a critical role in the life cycle by degrading the RNA strands of DNA/RNA hybrids. In addition, RNase H activity is required to precisely remove the RNA primers from nascent (-) and (+) strand DNA. We report here three crystal structures of the RNase H domain of xenotropic murine leukemia virus-related virus (XMRV) RT, namely (i) the previously identified construct from which helix C was deleted, (ii) the intact domain, and (iii) the intact domain complexed with an active site {alpha}-hydroxytropolone inhibitor. Enzymatic assays showed that the intact RNase H domain retained catalytic activity, whereas the variant lacking helix C was only marginally active, corroborating the importance of this helix for enzymatic activity. Modeling of the enzyme-substrate complex elucidated the essential role of helix C in binding a DNA/RNA hybrid and its likely mode of recognition. The crystal structure of the RNase H domain complexed with {beta}-thujaplicinol clearly showed that coordination by two divalent cations mediates recognition of the inhibitor.

  2. Fv-1 restriction of murine leukemia viruses: a model for studying host genetic control of retroviral gene movement and leukemogenesis

    SciTech Connect

    Yang, W.K.; Boone, L.R.; Tennant, R.W.; Brown, A.

    1983-01-01

    Since the first isolation of a murine leukemia, it has been noted that transmission of the leukemic disease is very much dependent on the mouse strain selected for the virus inoculation. There are many different genetic determinants that may render the most resistant to viral leukemogenesis. The most well-defined among these resistance genes is the Fv-1 locus, which is present in laboratory strains as well as in wild populations of the mouse. The Fv-1 locus, with its fundamental biology and genetics well established, is ideal for biochemical studies. The molecular mechanism elucidated for this restriction system may provide information useful for further studies to understand the complex genetic factors related to the control of carcinogenesis. Recent understanding of the interaction between host Fv-1 gene and the restricted virus may be summarized as follows: there are dominantly expressed Fv-1 gene products in the cell; there are specific target molecules in the virion; the restriction is an intracellular event which leads to failure of proviral DNA integration. On the basis of these basic facts as well as results of our detailed analysis of retroviral DNA intermediates in the Fv-1 restrictive cells, we have constructed a working hypothesis for the molecular mechanism of Fv-1 gene restriction, which places particular emphasis on the structural and functional behavior of long terminal repeats (LTR) during the early phase of retrovirus infection.

  3. Chromatin states shape insertion profiles of the piggyBac, Tol2 and Sleeping Beauty transposons and murine leukemia virus.

    PubMed

    Yoshida, Junko; Akagi, Keiko; Misawa, Ryo; Kokubu, Chikara; Takeda, Junji; Horie, Kyoji

    2017-03-02

    DNA transposons and retroviruses are versatile tools in functional genomics and gene therapy. To facilitate their application, we conducted a genome-wide insertion site profiling of the piggyBac (PB), Tol2 and Sleeping Beauty (SB) transposons and the murine leukemia virus (MLV) in mouse embryonic stem cells (ESCs). PB and MLV preferred highly expressed genes, whereas Tol2 and SB preferred weakly expressed genes. However, correlations with DNase I hypersensitive sites were different for all vectors, indicating that chromatin accessibility is not the sole determinant. Therefore, we analysed various chromatin states. PB and MLV highly correlated with Cohesin, Mediator and ESC-specific transcription factors. Notably, CTCF sites were correlated with PB but not with MLV, suggesting MLV prefers smaller promoter-enhancer loops, whereas PB insertion encompasses larger chromatin loops termed topologically associating domains. Tol2 also correlated with Cohesin and CTCF. However, correlations with ESC-specific transcription factors were weaker, suggesting that Tol2 prefers transcriptionally weak chromatin loops. Consistently, Tol2 insertions were associated with bivalent histone modifications characteristic of silent and inducible loci. SB showed minimum preference to all chromatin states, suggesting the least adverse effect on adjacent genes. These results will be useful for vector selection for various applications.

  4. Fidelity of Target Site Duplication and Sequence Preference during Integration of Xenotropic Murine Leukemia Virus-Related Virus

    PubMed Central

    Kim, Sanggu; Rusmevichientong, Alice; Dong, Beihua; Remenyi, Roland; Silverman, Robert H.; Chow, Samson A.

    2010-01-01

    Xenotropic murine leukemia virus (MLV)-related virus (XMRV) is a new human retrovirus associated with prostate cancer and chronic fatigue syndrome. The causal relationship of XMRV infection to human disease and the mechanism of pathogenicity have not been established. During retrovirus replication, integration of the cDNA copy of the viral RNA genome into the host cell chromosome is an essential step and involves coordinated joining of the two ends of the linear viral DNA into staggered sites on target DNA. Correct integration produces proviruses that are flanked by a short direct repeat, which varies from 4 to 6 bp among the retroviruses but is invariant for each particular retrovirus. Uncoordinated joining of the two viral DNA ends into target DNA can cause insertions, deletions, or other genomic alterations at the integration site. To determine the fidelity of XMRV integration, cells infected with XMRV were clonally expanded and DNA sequences at the viral-host DNA junctions were determined and analyzed. We found that a majority of the provirus ends were correctly processed and flanked by a 4-bp direct repeat of host DNA. A weak consensus sequence was also detected at the XMRV integration sites. We conclude that integration of XMRV DNA involves a coordinated joining of two viral DNA ends that are spaced 4 bp apart on the target DNA and proceeds with high fidelity. PMID:20421928

  5. Alpha-phellandrene-induced DNA damage and affect DNA repair protein expression in WEHI-3 murine leukemia cells in vitro.

    PubMed

    Lin, Jen-Jyh; Wu, Chih-Chung; Hsu, Shu-Chun; Weng, Shu-Wen; Ma, Yi-Shih; Huang, Yi-Ping; Lin, Jaung-Geng; Chung, Jing-Gung

    2015-11-01

    Although there are few reports regarding α-phellandrene (α-PA), a natural compound from Schinus molle L. essential oil, there is no report to show that α-PA induced DNA damage and affected DNA repair associated protein expression. Herein, we investigated the effects of α-PA on DNA damage and repair associated protein expression in murine leukemia cells. Flow cytometric assay was used to measure the effects of α-PA on total cell viability and the results indicated that α-PA induced cell death. Comet assay and 4,6-diamidino-2-phenylindole dihydrochloride staining were used for measuring DNA damage and condensation, respectively, and the results indicated that α-PA induced DNA damage and condensation in a concentration-dependent manner. DNA gel electrophoresis was used to examine the DNA damage and the results showed that α-PA induced DNA damage in WEHI-3 cells. Western blotting assay was used to measure the changes of DNA damage and repair associated protein expression and the results indicated that α-PA increased p-p53, p-H2A.X, 14-3-3-σ, and MDC1 protein expression but inhibited the protein of p53, MGMT, DNA-PK, and BRCA-1.

  6. CD45 phosphatase is crucial for human and murine acute myeloid leukemia maintenance through its localization in lipid rafts

    PubMed Central

    Saint-Paul, Laetitia; Nguyen, Chi-Hung; Buffière, Anne; de Barros, Jean-Paul Pais; Hammann, Arlette; Landras-Guetta, Corinne; Filomenko, Rodolphe; Chrétien, Marie-Lorraine; Johnson, Pauline; Bastie, Jean-Noël; Delva, Laurent; Quéré, Ronan

    2016-01-01

    CD45 is a pan-leukocyte protein with tyrosine phosphatase activity involved in the regulation of signal transduction in hematopoiesis. Exploiting CD45 KO mice and lentiviral shRNA, we prove the crucial role that CD45 plays in acute myeloid leukemia (AML) development and maintenance. We discovered that CD45 does not colocalize with lipid rafts on murine and human non-transformed hematopoietic cells. Using a mouse model, we proved that CD45 positioning within lipid rafts is modified during their oncogenic transformation to AML. CD45 colocalized with lipid rafts on AML cells, which contributes to elevated GM-CSF signal intensity involved in proliferation of leukemic cells. We furthermore proved that the GM-CSF/Lyn/Stat3 pathway that contributes to growth of leukemic cells could be profoundly affected, by using a new plasma membrane disrupting agent, which rapidly delocalized CD45 away from lipid rafts. We provide evidence that this mechanism is also effective on human primary AML samples and xenograft transplantation. In conclusion, this study highlights the emerging evidence of the involvement of lipid rafts in oncogenic development of AML and the targeting of CD45 positioning among lipid rafts as a new strategy in the treatment of AML. PMID:27579617

  7. Lysosomal processing of sialoglycoconjugates in a wheat germ agglutinin resistant variant of EL4 murine leukemia cells

    SciTech Connect

    Devino, N.L.

    1989-01-01

    Metabolic studies were undertaken in EL4 murine leukemia in WB6, a wheat germ agglutinin-resistant variant of EL4, in order to identify any differences in lysosomal processing of sialoglyco-conjugates. Five lysosomal acid hydrolases, acetylesterase, acid phosphatase, {beta}-galactosidase, {alpha}-mannosidase, and neuraminidase, were studied using fluorescent 4-methylumbelliferyl substrates. No significant differences were found in the total activity of any of these enzymes in EL4 and WB6. Cells were incubated in the presence of N-acetylmannosamine, the metabolic precursor of sialic acid (N-acetylneuraminic acid). Free sialic acid accumulated in the lysosomes of WB6 but not of EL4. The accumulation of lysosomal free sialic acid in WB6 showed a dependence on the concentration of N-acetylmannosamine in the growth medium. Metabolic labelling with (6-{sup 3}H)-N-acetylmannosamine showed that WB6 accumulated lysosomal free sialic acid even at very low concentrations of N-acetylmannosamine. The two cell lines differed in their distribution of radiolabelled neutral sugars, free sialic acid, and sialoglycoproteins. The velocity of {sup 3}H-sialic acid release was 3.7-fold lower in WB6 than in EL4, suggesting that WB6 has a defect in lysosomal sialic acid transport. The metabolic consequences of this defect are examined, in light of other biochemical and immunological data on these cells.

  8. Functional and Structural Characterization of Novel Type of Linker Connecting Capsid and Nucleocapsid Protein Domains in Murine Leukemia Virus.

    PubMed

    Doležal, Michal; Hadravová, Romana; Kožíšek, Milan; Bednárová, Lucie; Langerová, Hana; Ruml, Tomáš; Rumlová, Michaela

    2016-09-23

    The assembly of immature retroviral particles is initiated in the cytoplasm by the binding of the structural polyprotein precursor Gag with viral genomic RNA. The protein interactions necessary for assembly are mediated predominantly by the capsid (CA) and nucleocapsid (NC) domains, which have conserved structures. In contrast, the structural arrangement of the CA-NC connecting region differs between retroviral species. In HIV-1 and Rous sarcoma virus, this region forms a rod-like structure that separates the CA and NC domains, whereas in Mason-Pfizer monkey virus, this region is densely packed, thus holding the CA and NC domains in close proximity. Interestingly, the sequence connecting the CA and NC domains in gammaretroviruses, such as murine leukemia virus (MLV), is unique. The sequence is called a charged assembly helix (CAH) due to a high number of positively and negatively charged residues. Although both computational and deletion analyses suggested that the MLV CAH forms a helical conformation, no structural or biochemical data supporting this hypothesis have been published. Using an in vitro assembly assay, alanine scanning mutagenesis, and biophysical techniques (circular dichroism, NMR, microcalorimetry, and electrophoretic mobility shift assay), we have characterized the structure and function of the MLV CAH. We provide experimental evidence that the MLV CAH belongs to a group of charged, E(R/K)-rich, single α-helices. This is the first single α-helix motif identified in viral proteins.

  9. Immunoprophylactic potential of wheat grass extract on benzene-induced leukemia: An in vivo study on murine model

    PubMed Central

    Khan, Neelofar; Ganeshpurkar, Aditya; Dubey, Nazneen; Bansal, Divya

    2015-01-01

    Objectives: Wheat grass (Triticum aestivum) is a gift of nature given to mankind. A number of scientific research on wheatgrass establishes its anticancer and antioxidant potential. Current work was focused to determine antileukemic effect of wheat grass. Materials and Methods: The commercial wheatgrass powder was extracted with 95% of methanol. Methanol extract of wheat grass was studied for acute oral toxicity as per revised Organization for Economic Cooperation and Development Guidelines number 423. Leukemia was successfully induced in Wister rats by intravenous injection of benzene. The blood was collected and analyzed for hematological parameters. Phagocytotic activity of the extract was determined. Results: Phytochemical screening revealed the presence of flavonoids, phenolics, carbohydrates, and amino acids. From acute toxicity studies, it was found that the methanol extract of wheatgrass was safe up to a dose level of 2000 mg/kg of body weight. Outcomes of hematological parameters in various experimental groups of murine model demonstrated antileukemic effect of extract. Methanol extract of wheatgrass aroused the process of phagocytosis of killed Candida albicans and also demonstrated a significant chemotactic activity at all tested concentrations. Conclusion: In the current work, methanol extract of wheat grass demonstrated antileukemic potential that might be due to the presence of flavonoids and polyphenolics in it. Further isolation, structural characterization of active constituents is necessary to extrapolate the mechanism of action. PMID:26288471

  10. Changes in p19Arf Localization Accompany Apoptotic Crisis during Pre-B-Cell Transformation by Abelson Murine Leukemia Virus▿

    PubMed Central

    Zimmerman, Rebekah Stackpole; Rosenberg, Naomi

    2008-01-01

    Transformation by Abelson murine leukemia virus (Ab-MLV) is a multistep process in which growth-stimulatory signals from the v-Abl oncoprotein and growth-suppressive signals from the p19Arf-p53 tumor suppressor pathway oppose each other and influence the outcome of infection. The process involves a proliferative phase during which highly viable primary transformants expand, followed by a period of marked apoptosis (called “crisis”) that is dependent on the presence of p19Arf and p53; rare cells that survive this phase emerge as fully transformed and malignant. To understand the way in which v-Abl expression affects p19Arf expression, we examined changes in expression of Arf during all stages of Ab-MLV transformation process. As is consistent with the ability of v-Abl to stimulate Myc, a transcription factor known to induce p19Arf, Myc and Arf are induced soon after infection and p19Arf is expressed. At these early time points, the infected cells remain highly viable. The onset of crisis is marked by an increase in p19Arf expression and a change in localization of the protein from the nucleoplasm to the nucleolus. These data together suggest that the localization and expression levels of p19Arf modulate the effects of the protein during oncogenesis and reveal that the p19Arf-mediated response is subject to multiple layers of regulation that influence its function during Ab-MLV-mediated transformation. PMID:18579612

  11. Specific sequence deletions in two classes of murine leukemia virus-related proviruses in the mouse genome.

    PubMed

    Ch'ang, L Y; Yang, W K; Myer, F E; Koh, C K; Boone, L R

    1989-02-01

    Characteristic long terminal repeats (LTR) of approximately 700 and 750 bp were found, respectively, in the two classes (polytropic and modified polytropic) of murine leukemia virus (MuLV)-related nonecotropic nonxenotropic proviral sequences in eight individual molecular clones of RFM/Un mouse chromosomal DNA fragments. Three proviral clones, two polytropic and one modified polytropic, contained sequence deletions in the viral structural genes. Nucleotide sequence analysis revealed that 7-bp direct repeats occur at both ends of deleted sequences in intact structures and one of the repeats remains in genomes with the deletion. Specifically, the deleted sequences were a 1487-bp gag-pol sequence with ACTGCCC repeat, a 113-bp mid-pol sequence with CAGGCAA repeat, and a 1811-bp env sequence with GGTCCAG repeat. The same specific sequence deletions were found in both classes of MuLV-related proviral structures. Examination of chromosomal DNA from eight inbred laboratory mouse strains and six wild mouse species showed that a minor population of proviruses with these specific deletions were present in Mus musculus and Mus spretus, all of which contain prominent 700-bp LTR polytropic proviral structures. The 750-bp LTR modified polytropic proviral structures were phylogenetically more restricted, being equally predominant in Mus musculus domesticus mice, but minor to undetectable in Mus spretus subspecies, and absent in other wild mouse populations.

  12. CD45 phosphatase is crucial for human and murine acute myeloid leukemia maintenance through its localization in lipid rafts.

    PubMed

    Saint-Paul, Laetitia; Nguyen, Chi-Hung; Buffière, Anne; Pais de Barros, Jean-Paul; Hammann, Arlette; Landras-Guetta, Corinne; Filomenko, Rodolphe; Chrétien, Marie-Lorraine; Johnson, Pauline; Bastie, Jean-Noël; Delva, Laurent; Quéré, Ronan

    2016-10-04

    CD45 is a pan-leukocyte protein with tyrosine phosphatase activity involved in the regulation of signal transduction in hematopoiesis. Exploiting CD45 KO mice and lentiviral shRNA, we prove the crucial role that CD45 plays in acute myeloid leukemia (AML) development and maintenance. We discovered that CD45 does not colocalize with lipid rafts on murine and human non-transformed hematopoietic cells. Using a mouse model, we proved that CD45 positioning within lipid rafts is modified during their oncogenic transformation to AML. CD45 colocalized with lipid rafts on AML cells, which contributes to elevated GM-CSF signal intensity involved in proliferation of leukemic cells. We furthermore proved that the GM-CSF/Lyn/Stat3 pathway that contributes to growth of leukemic cells could be profoundly affected, by using a new plasma membrane disrupting agent, which rapidly delocalized CD45 away from lipid rafts. We provide evidence that this mechanism is also effective on human primary AML samples and xenograft transplantation. In conclusion, this study highlights the emerging evidence of the involvement of lipid rafts in oncogenic development of AML and the targeting of CD45 positioning among lipid rafts as a new strategy in the treatment of AML.

  13. Interactions of Murine Leukemia Virus Core Components: Characterization of Reverse Transcriptase Packaged in the Absence of 70S Genomic RNA

    PubMed Central

    Gerwin, Brenda I.; Levin, Judith G.

    1977-01-01

    Virions produced by cells in the presence of actinomycin D (Act D virions) contain reverse transcriptase but are deficient in 70S genomic RNA. To assess the role of genomic RNA in encapsidation of a functional reverse transcriptase and to study the interaction of the enzyme and its template in the cores of intact virions, the reverse transcriptase enzymes of normal and Act D virions were compared. The enzymes were indistinguishable by column chromatography, sedimentation velocity, or template/primer preferences. In addition, these enzymes showed equal sensitivity to inactivation by antibodies directed against Rauscher murine leukemia virus DNA polymerase. The enzymes from Act D and normal virions had similar thermal decay rates and were both protected against heat denaturation by natural and synthetic template/primers. By these criteria, the DNA polymerase molecules synthesized and assembled into virions in the absence of genomic RNA are identical to those packaged under normal conditions. Additional studies designed to measure protection of reverse transcriptase by genomic RNA were carried out by comparing the thermal lability of the enzyme in intact Act D and normal virions. The thermal decay rate of reverse transcriptase in Act D virions was identical to that in control virions. In contrast to the lability of the virion-associated enzyme, however, genomic RNA in control virions was stable to heat treatment. PMID:72160

  14. The 17 Nucleotides Downstream from the env Gene Stop Codon Are Important for Murine Leukemia Virus Packaging

    PubMed Central

    Shin Yu, Seung; Kim, Jong-Mook; Kim, Sunyoung

    2000-01-01

    We have identified a previously unknown nucleotide sequence important for the packaging of murine leukemia virus. This nucleotide sequence is located downstream from the stop codon of the env gene but does not overlap the polypurine tract. Deletion of 17 bp from this region resulted in a more than 10-fold decrease in viral titer. Consistent with this result, the deletion mutant showed a 20- to 30-fold drop in the amount of virion RNA in the culture supernatant. The total amount of virion protein in the culture supernatant was comparable for the deletion mutant and the parental virus, suggesting that the mutant construct could release the empty viral particles. These results suggested that the packaging signal sequence might be present at the two extreme sites of the viral genome, one in the region around the splice donor sequence downstream from the 5′ long terminal repeat (LTR) and the other immediately upstream from the 3′ LTR. Implications for gene therapy, especially in regard to construction of retroviral vectors and packaging constructs, are discussed. PMID:10954583

  15. Human and murine pituitary expression of leukemia inhibitory factor. Novel intrapituitary regulation of adrenocorticotropin hormone synthesis and secretion.

    PubMed Central

    Akita, S; Webster, J; Ren, S G; Takino, H; Said, J; Zand, O; Melmed, S

    1995-01-01

    Leukemia inhibitory factor (LIF) gene expression was detected in human fetal pituitary tissue by expression of LIF mRNA transcripts, protein immunocytochemistry, and immunoelectron microscopy. Fetal LIF immunoreactivity colocalized with 30% of ACTH-expressing cells, approximately 20% of somatotrophs, and approximately 15% of non-hormone-expressing cells. LIF was also strongly expressed in normal adult pituitary and in four growth hormone-producing and two ACTH-producing adenomas, but not in eight nonfunctioning pituitary tumors. Culture of fetal cells expressing surface LIF-binding sites demonstrated predominance of in vitro ACTH secretion as compared with other pituitary hormones. In AtT-20 murine cells, LIF (ED50 10 pM) stimulated basal proopiomelanocortin mRNA levels by 40% and corticotropin-releasing hormone-induced ACTH secretion (two- to threefold), as did oncostatin M (ED50 30 pM), a related peptide. ACTH responses were not further enhanced by both cytokines together, which is consistent with their shared receptor. Anti-LIF antiserum neutralized basal and LIF-induced ACTH secretion, suggesting autocrine regulation of ACTH by LIF. The results show that human pituitary cells express the LIF gene and LIF-binding sites, predominantly in corticotrophs. Pituitary LIF expression and LIF regulation of proopiomelanocortin and ACTH reflect an intrapituitary role for LIF in modulating early embryonic determination of specific human pituitary cells and as a paracrine or autocrine regulator of mature ACTH. Images PMID:7883977

  16. Tyrosine phosphorylation of HSC70 and its interaction with RFC mediates methotrexate resistance in murine L1210 leukemia cells.

    PubMed

    Liu, Tuoen; Singh, Ratan; Rios, Zechary; Bhushan, Alok; Li, Mengxiong; Sheridan, Peter P; Bearden, Shawn E; Lai, James C K; Agbenowu, Senyo; Cao, Shousong; Daniels, Christopher K

    2015-02-01

    We previously identified and characterized a 66-68 kDa membrane-associated, tyrosine phosphorylated protein in murine leukemia L1210 cells as HSC70 which is a methotrexate (MTX)-binding protein. In order to further characterize the functional role of HSC70 in regulating MTX resistance in L1210 cells, we first showed that HSC70 colocalizes and interacts with reduced folate carrier (RFC) in L1210 cells by confocal laser scanning microscopy and Duolink in situ proximity ligation assay. The tyrosine phosphorylation status of HSC70 found in the membrane fraction was different from the parental L1210/0 and cisplatin (CDDP)-MTX cross resistant L1210/DDP cells. In MTX-binding assays, HSC70 from L1210/DDP cells showed less affinity for MTX-agarose beads than that of L1210/0 cells. In addition, genistein (a tyrosine phosphorylation inhibitor) significantly enhanced the resistance of L1210/0 cells to MTX. Moreover, site-directed mutation studies indicated the importance of tyrosine phosphorylation of HSC70 in regulating its binding to MTX. These findings suggest that tyrosine phosphorylation of HSC70 regulates the transportation of MTX into the cells via the HSC70-RFC system and contributes to MTX resistance in L1210 cells.

  17. Accelerated appearance of multiple B cell lymphoma types in NFS/N mice congenic for ecotropic murine leukemia viruses.

    PubMed

    Hartley, J W; Chattopadhyay, S K; Lander, M R; Taddesse-Heath, L; Naghashfar, Z; Morse, H C; Fredrickson, T N

    2000-02-01

    Spontaneous lymphomas occur at high frequency in NFS x V+ mice, strains congenic for ecotropic murine leukemia virus (MuLV) proviral genes and expressing virus at high titer. In the present study, a total of 703 NFS x V+ lymphomas were studied by histopathology, immunophenotypic analysis, immunoglobulin heavy chain or T cell receptor beta chain rearrangements, and somatic ecotropic MuLV integrations; 90% of the lymphomas tested were of B cell lineage. Low-grade tumors included small lymphocytic, follicular, and splenic marginal zone lymphomas, while high-grade tumors comprised diffuse large-cell (centroblastic and immunoblastic types), splenic marginal zone, and lymphoblastic lymphomas. Comparison of mice of similar genetic background except for presence (NFS x V+) or absence (NFS x V-) of functional ecotropic MuLV genomes showed that NFS x V-clonal lymphomas developed at about one-half the rate of those occurring in NFS x V+ mice, and most were low-grade B cell lymphomas with extended latent periods. In NFS x V+ mice, clonal outgrowth, defined by Ig gene rearrangements, was associated with acquisition of somatic ecotropic proviral integrations, suggesting that, although generation of B cell clones can be virus independent, ecotropic virus may act to increase the rate of generation of clones and speed their evolution to lymphoma. The mechanism remains undefined, because only rare rearrangements were detected in several cellular loci previously associated with MuLV insertional mutagenesis.

  18. Prevention of Contamination by Xenotropic Murine Leukemia Virus-Related Virus: Susceptibility to Alcohol-Based Disinfectants and Environmental Stability

    PubMed Central

    Palesch, David; Khalid, Mohammad; Stürzel, Christina M.

    2014-01-01

    Xenotropic murine leukemia virus-related virus (XMRV) represents a novel γ-retrovirus that is capable of infecting human cells and has been classified as a biosafety level 2 (BSL-2) organism. Hence, XMRV represents a potential risk for personnel in laboratories worldwide. Here, we measured the stability of XMRV and its susceptibility to alcohol-based disinfectants. To this end, we exposed an infectious XMRV reporter virus encoding a secretable luciferase to different temperatures, pH values, and disinfectants and infected XMRV-permissive Raji B cells to measure residual viral infectivity. We found that 1 min treatment of XMRV particles at 60°C is sufficient to reduce infectivity by 99.9%. XMRV infectivity was maximal at a neutral pH but was reduced by 86% at pH 4 and 99.9% at pH 10. The common hand and surface disinfectants ethanol and isopropanol as well as the cell fixation reagent paraformaldehyde abrogated XMRV infectivity entirely, as indicated by a reduction of infectivity exceeding 99.99%. Our findings provide evidence of specific means to inactivate XMRV. Their application will help to prevent unintended XMRV contamination of cell cultures in laboratories and minimize the risk for laboratory personnel and health care workers to become infected with this biosafety level 2 organism. PMID:24532072

  19. Prevention of contamination by xenotropic murine leukemia virus-related virus: susceptibility to alcohol-based disinfectants and environmental stability.

    PubMed

    Palesch, David; Khalid, Mohammad; Stürzel, Christina M; Münch, Jan

    2014-04-01

    Xenotropic murine leukemia virus-related virus (XMRV) represents a novel γ-retrovirus that is capable of infecting human cells and has been classified as a biosafety level 2 (BSL-2) organism. Hence, XMRV represents a potential risk for personnel in laboratories worldwide. Here, we measured the stability of XMRV and its susceptibility to alcohol-based disinfectants. To this end, we exposed an infectious XMRV reporter virus encoding a secretable luciferase to different temperatures, pH values, and disinfectants and infected XMRV-permissive Raji B cells to measure residual viral infectivity. We found that 1 min treatment of XMRV particles at 60°C is sufficient to reduce infectivity by 99.9%. XMRV infectivity was maximal at a neutral pH but was reduced by 86% at pH 4 and 99.9% at pH 10. The common hand and surface disinfectants ethanol and isopropanol as well as the cell fixation reagent paraformaldehyde abrogated XMRV infectivity entirely, as indicated by a reduction of infectivity exceeding 99.99%. Our findings provide evidence of specific means to inactivate XMRV. Their application will help to prevent unintended XMRV contamination of cell cultures in laboratories and minimize the risk for laboratory personnel and health care workers to become infected with this biosafety level 2 organism.

  20. A murine model of acute myeloid leukemia with Evi1 overexpression and autocrine stimulation by an intracellular form of GM-CSF in DA-3 cells.

    PubMed

    Cardona, Maria E; Simonson, Oscar E; Oprea, Iulian I; Moreno, Pedro M D; Silva-Lara, Maria F; Mohamed, Abdalla J; Christensson, Birger; Gahrton, Gösta; Dilber, M Sirac; Smith, C I Edvard; Arteaga, H Jose

    2016-01-01

    The poor treatment response of acute myeloid leukemia (AML) overexpressing high-risk oncogenes such as EVI1, demands specific animal models for new treatment evaluations. Evi1 is a common site of activating integrations in murine leukemia virus (MLV)-induced AML and in retroviral and lentiviral gene-modified HCS. Still, a model of overt AML induced by Evi1 has not been generated. Cell lines from MLV-induced AML are growth factor-dependent and non-transplantable. Hence, for the leukemia maintenance in the infected animals, a growth factor source such as chronic immune response has been suggested. We have investigated whether these leukemias are transplantable if provided with growth factors. We show that the Evi1(+)DA-3 cells modified to express an intracellular form of GM-CSF, acquired growth factor independence and transplantability and caused an overt leukemia in syngeneic hosts, without increasing serum GM-CSF levels. We propose this as a general approach for modeling different forms of high-risk human AML using similar cell lines.

  1. Normal sister chromatid exchange frequencies during growth of a transplantable murine myeloid leukemia

    SciTech Connect

    Au, W.W.; Goldenthal, K.L.

    1985-01-01

    Frequencies of sister chromatid exchange (SCE) were analyzed in normal and coexisting leukemic cells harvested from the bone marrow of mice 10, 15, 18, and 21 days after transplantation of myeloid leukemic cells. These posttransplantation stages correspond to no abnormal physical or clinical symptoms (day 10) through the terminal stage of leukemia (day 21). The data indicate that the SCE frequencies in normal cells of leukemic mice did not differ from those in normal cells of normal mice. Furthermore, the frequencies in the coexisting normal and leukemic cells remained statistically constant throughout the posttransplantation period. It is concluded from this study that spontaneous cellular SCE frequencies may not be altered by the presence or growth of leukemic cells. 15 references, 1 figure, 1 table.

  2. Novel principles of gamma-retroviral insertional transcription activation in murine leukemia virus-induced end-stage tumors.

    PubMed

    Sokol, Martin; Wabl, Matthias; Ruiz, Irene Rius; Pedersen, Finn Skou

    2014-05-19

    Insertional mutagenesis screens of retrovirus-induced mouse tumors have proven valuable in human cancer research and for understanding adverse effects of retroviral-based gene therapies. In previous studies, the assignment of mouse genes to individual retroviral integration sites has been based on close proximity and expression patterns of annotated genes at target positions in the genome. We here employed next-generation RNA sequencing to map retroviral-mouse chimeric junctions genome-wide, and to identify local patterns of transcription activation in T-lymphomas induced by the murine leukemia gamma-retrovirus SL3-3. Moreover, to determine epigenetic integration preferences underlying long-range gene activation by retroviruses, the colocalization propensity with common epigenetic enhancer markers (H3K4Me1 and H3K27Ac) of 6,117 integrations derived from end-stage tumors of more than 2,000 mice was examined. We detected several novel mechanisms of retroviral insertional mutagenesis: bidirectional activation of mouse transcripts on opposite sides of a provirus including transcription of unannotated mouse sequence; sense/antisense-type activation of genes located on opposite DNA strands; tandem-type activation of distal genes that are positioned adjacently on the same DNA strand; activation of genes that are not the direct integration targets; combination-type insertional mutagenesis, in which enhancer activation, alternative chimeric splicing and retroviral promoter insertion are induced by a single retrovirus. We also show that irrespective of the distance to transcription start sites, the far majority of retroviruses in end-stage tumors colocalize with H3K4Me1 and H3K27Ac-enriched regions in murine lymphoid tissues. We expose novel retrovirus-induced host transcription activation patterns that reach beyond a single and nearest annotated gene target. Awareness of this previously undescribed layer of complexity may prove important for elucidation of adverse effects

  3. Pretargeted Radioimmunotherapy Using Anti-CD45 Monoclonal Antibodies to Deliver Radiation to Murine Hematolymphoid Tissues and Human Myeloid Leukemia

    SciTech Connect

    Pagel, John M.; Matthews, Dana C.; Kenoyer, Aimee L.; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.; Gopal, Ajay K.; Lin, Yukang; Saganic, Laura; Appelbaum, Frederick R.; Press, Oliver W.

    2009-01-01

    The efficacy of radioimmunotherapy (RIT) for treatment of patients with hematological malignancies frequently fails because of disease recurrence. We therefore conducted pretargeted RIT studies to augment the efficacy in mice of therapy using a pretargeted anti-human (h)CD45 antibody (Ab)-streptavidin (SA) conjugate followed by delivery of a biotinylated clearing agent and radiolabeled-DOTA-biotin. Tumor-to-blood ratios at 24 hours were 20:1 using pretargeted anti-hCD45 RIT and <1:1 with conventional RIT. In vivo imaging studies confirmed that the pretargeted RIT approach provided high-contrast tumor images with minimal blood-pool activity, whereas directly-labeled anti-hCD45 Ab produced distinct tumor images but the blood pool retained a large amount of labeled antibody for a prolonged time. Therapy experiments demonstrated that 90Y-DOTA-biotin significantly prolonged survival of mice treated pretargeted with anti-hCD45 Ab-SA compared to mice treated with conventional RIT using 90Y-labeled anti-hCD45 Ab at the maximally tolerated dose (400 µCi). Since human CD45 antigens are confined to xenograft tumor cells in this model, and all murine tissues are devoid of hCD45 and will not bind anti-hCD45 Ab, we also compared one-step and pretargeted RIT using an anti-murine (m)CD45 Ab (A20 ) in a model where the target antigen is present on normal hematopoietic tissues. After 24 hours, 27.3 ± 2.8% of the injected dose of radionuclide was delivered per gram (% ID/g) of lymph node using 131I-A20-Ab compared with 40.0 ± 5.4% ID/g for pretargeted 111In-DOTA-biotin (p value). These data suggest that multi-step pretargeted methods for delivering RIT are superior to conventional RIT when targeting CD45 for the treatment of leukemia and may allow for the intensification of therapy, while minimizing toxicities.

  4. Polymer therapeutics with a coiled coil motif targeted against murine bcl1 leukemia.

    PubMed

    Pola, Robert; Laga, Richard; Ulbrich, Karel; Sieglová, Irena; Král, Vlastimil; Fábry, Milan; Kabešová, Martina; Kovář, Marek; Pechar, Michal

    2013-03-11

    The specificity of polymer conjugates based on N-(2-hydroxypropyl)methacrylamide (HPMA) bearing cytostatic drugs for cancer cells could be significantly increased by the incorporation of a suitable targeting ligand, such as a monoclonal antibody (mAb). However, direct binding of the protein to the polymer carrier could cause considerable problems, such as decreasing the binding capacity of mAb to its target. Here, we introduce a novel strategy of joining a targeting moiety to a polymeric conjugate with cytostatic drug. The scFv of B1 mAb (specific for BCL1 leukemia cells) was tagged with peptide K ((VAALKEK)4). Peptide E ((VAALEKE)4), which forms a stable coiled coil structure heterodimer with peptide K, was assembled with the HPMA copolymers bearing doxorubicin. Such targeted polymeric conjugates possess very selective and high binding activity toward BCL1 cells. Similarly, targeted polymeric conjugates exert approximately 100 times higher cytostatic activity toward BCL1 cells in comparison to nontargeted conjugates in vitro. At the same time, the conjugates have comparable and rather low cytostatic activity for 38C13 cells, which are used as a negative control, in vitro.

  5. Role of Murine Leukemia Virus Reverse Transcriptase Deoxyribonucleoside Triphosphate-Binding Site in Retroviral Replication and In Vivo Fidelity

    PubMed Central

    Halvas, Elias K.; Svarovskaia, Evguenia S.; Pathak, Vinay K.

    2000-01-01

    Retroviral populations exhibit a high evolutionary potential, giving rise to extensive genetic variation. Error-prone DNA synthesis catalyzed by reverse transcriptase (RT) generates variation in retroviral populations. Structural features within RTs are likely to contribute to the high rate of errors that occur during reverse transcription. We sought to determine whether amino acids within murine leukemia virus (MLV) RT that contact the deoxyribonucleoside triphosphate (dNTP) substrate are important for in vivo fidelity of reverse transcription. We utilized the previously described ANGIE P encapsidating cell line, which expresses the amphotropic MLV envelope and a retroviral vector (pGA-1). pGA-1 expresses the bacterial β-galactosidase gene (lacZ), which serves as a reporter of mutations. Extensive mutagenesis was performed on residues likely to interact with the dNTP substrate, and the effects of these mutations on the fidelity of reverse transcription were determined. As expected, most substitution mutations of amino acids that directly interact with the dNTP substrate significantly reduced viral titers (>10,000-fold), indicating that these residues played a critical role in catalysis and viral replication. However, the D153A and A154S substitutions, which are predicted to affect the interactions with the triphosphate, resulted in statistically significant increases in the mutation rate. In addition, the conservative substitution F155W, which may affect interactions with the base and the ribose, increased the mutation rate 2.8-fold. Substitutions of residues in the vicinity of the dNTP-binding site also resulted in statistically significant decreases in fidelity (1.3- to 2.4-fold). These results suggest that mutations of residues that contact the substrate dNTP can affect viral replication as well as alter the fidelity of reverse transcription. PMID:11044079

  6. Seroprevalence of xenotropic murine leukemia virus-related virus in normal and retrovirus-infected blood donors.

    PubMed

    Qiu, Xiaoxing; Swanson, Priscilla; Tang, Ning; Leckie, Gregor W; Devare, Sushil G; Schochetman, Gerald; Hackett, John

    2012-02-01

    Xenotropic murine leukemia virus-related virus (XMRV) has been reported in patients with prostate cancer and chronic fatigue syndrome. Although results have been conflicting, the potential of XMRV as an infectious human retrovirus has raised concerns about transfusion safety. To address this issue, normal and retrovirus-infected blood donors were screened for evidence of XMRV infection. Plasma from 1000 US, 100 human immunodeficiency virus Type 1-infected Cameroonian, and 642 human T-lymphotropic virus Type I (HTLV-I)-infected or uninfected Japanese blood donors as well as 311 sexually transmitted disease diagnostic specimens were screened for antibodies to XMRV gp70 and p15E using chemiluminescent immunoassays (CMIAs). CMIA-reactive samples were evaluated by p30 CMIA, Western blot, and real-time reverse transcriptase polymerase chain reaction. XMRV seroreactivity was low (0%-0.6%) with the exception of the HTLV-I-infected donors (4.9%). Antibody was detected against only a single XMRV protein (p15E or gp70); none of the seroreactive samples had detectable XMRV pol or env sequences. The elevated seroreactivity in HTLV-I-infected donors was due to an increased p15E seroreactive rate (4.1%). Inspection of XMRV and HTLV sequences revealed a high level of conservation within the immunodominant region (IDR) of the transmembrane protein. In some cases, HTLV IDR peptide competitively reduced the XMRV p15E signal. Based on the low prevalence of seroreactivity, detection of antibody to only a single XMRV protein and the absence of XMRV sequences, this study finds no compelling evidence of XMRV in normal or retrovirus-infected blood donors. The increased p15E seroreactivity observed in HTLV infection is likely due to cross-reactive antibodies. © 2012 American Association of Blood Banks.

  7. Comparative kinetic analyses of interaction of inhibitors with Rauscher murine leukemia virus and human immunodeficiency virus reverse transcriptases.

    PubMed Central

    Cherrington, J M; Fuller, M D; Mulato, A S; Allen, S J; Kunder, S C; Ussery, M A; Lesnikowski, Z; Schinazi, R F; Sommadossi, J P; Chen, M S

    1996-01-01

    The inhibitory effects of several nucleoside triphosphate analogs on Rauscher murine leukemia virus (RMuLV) and human immunodeficiency virus (HIV) type 1 reverse transcriptases (RTs) were studied. With RNA as the template, the apparent K(m) and apparent K(i) values of HIV RT toward its substrates and inhibitors are 12 to 500 times lower than the corresponding values for RMuLV RT. However, the k(i)/k(m) ratios (inhibition efficiencies) for HIV and RMuLV RTs'are similar for AZTTP (zidovudine triphosphate), d4TTP [3'-deoxythymidine-2'-ene-(3'-deoxy-2',3'-didehydrothymidine) triphosphate], PMEADP [9-(2-phosphonylmethoxyethyl)adenine diphosphate], FIAUTP [1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl)-5-iodouracil triphosphate], and HPMPCDP [(S)-1-(3-hydroxy-2-phosphylmethoxypropyl) cytosine diphosphate]. With DNA as the template, the K(m) values are similar for HIV and RMuLV RTs. However, the K(i)/K(m) values of HIV and RMuLV RTs are significantly different for ddCTP, ddATP, and 3TCTP (2',3'-dideoxy-3'-thiacytidine). The RTs of RMuLV and HIV are sufficiently different from one another that the kinetic inhibition constants for a particular antiviral compounds should be determined to indicate whether anti-RMuLV activity is likely to be predictive for the anti-HIV activity of the compound. This information, in conjunction with species-specific drug metabolism differences and tissue culture antiviral activity, is important in determining the suitability of a particular animal model. PMID:8723481

  8. Effect of Doxorubicin/Pluronic SP1049C on Tumorigenicity, Aggressiveness, DNA Methylation and Stem Cell Markers in Murine Leukemia

    PubMed Central

    Li, Shu; Kabanov, Alexander V.

    2013-01-01

    Purpose Pluronic block copolymers are potent sensitizers of multidrug resistant cancers. SP1049C, a Pluronic-based micellar formulation of doxorubicin (Dox) has completed Phase II clinical trial and demonstrated safety and efficacy in patients with advanced adenocarcinoma of the esophagus and gastroesophageal junction. This study elucidates the ability of SP1049C to deplete cancer stem cells (CSC) and decrease tumorigenicity of cancer cells in vivo. Experimental Design P388 murine leukemia ascitic tumor was grown in BDF1 mice. The animals were treated with: (a) saline, (b) Pluronics alone, (c) Dox or (d) SP1049C. The ascitic cancer cells were isolated at different passages and examined for 1) in vitro colony formation potential, 2) in vivo tumorigenicity and aggressiveness, 3) development of drug resistance and Wnt signaling activation 4) global DNA methylation profiles, and 5) expression of CSC markers. Results SP1049C treatment reduced tumor aggressiveness, in vivo tumor formation frequency and in vitro clonogenic potential of the ascitic cells compared to drug, saline and polymer controls. SP1049C also prevented overexpression of BCRP and activation of Wnt-β-catenin signaling observed with Dox alone. Moreover, SP1049C significantly altered the DNA methylation profiles of the cells. Finally, SP1049C decreased CD133+ P388 cells populations, which displayed CSC-like properties and were more tumorigenic compared to CD133− cells. Conclusions SP1049C therapy effectively suppresses the tumorigenicity and aggressiveness of P388 cells in a mouse model. This may be due to enhanced activity of SP1049C against CSC and/or altered epigenetic regulation restricting appearance of malignant cancer cell phenotype. PMID:23977261

  9. Comparative study of the growth-inhibitory and apoptosis-inducing activities of black tea theaflavins and green tea catechin on murine myeloid leukemia cells.

    PubMed

    Lung, Hong-Lok; Ip, Wai-Ki; Chen, Zhen-Yu; Mak, Nai-Ki; Leung, Kwok-Nam

    2004-03-01

    Among the black tea polyphenols, theaflavins are generally considered to be the more effective components for the inhibition of carcinogenesis. In this study, we attempted to compare the growth-inhibitory and apoptosis-inducing activities of the four black tea theaflavins (TF-1, TF-2A, TF-2B and TF-3) with the major green tea catechin epigallocatechin-3-gallate (EGCG) on the murine myeloid leukemia WEHI-3B JCS cells. All the four black tea theaflavins were shown to exert potent anti-proliferative and cytotoxic effects on the leukemia WEHI-3B JCS cells in a dose-dependent manner. The observed anti-proliferative and cytotoxic effects were in the following order of potency: EGCG > TF-2B > TF-3 > TF-2A > TF-1. In addition, all theaflavins were capable of inducing apoptosis in the leukemia WEHI-3B JCS cells. Among the four theaflavins tested, TF-2B and TF-3 were found to be slightly more potent in inducing apoptosis of the WEHI-3B JCS cells than that of TF-2A and TF-1 but were comparable to the major green tea epicatechin EGCG. More interestingly, both TF-2B and TF-3 were found to be much more effective than TF-1 and TF-2B in reducing both the in vitro clonogenicity and in vivo tumorigenicity of the WEHI-3B JCS cells, suggesting that these two black tea theaflavins might represent potential candidates for the treatment of some forms of leukemia.

  10. Biochemical effects and therapeutic potential of tunicamycin in murine L1210 leukemia

    SciTech Connect

    Morin, M.J.; Bernacki, R.J.

    1983-04-01

    Tunicamycin, an antibiotic which specifically inhibits the dolichol-mediated synthesis of glycoproteins, significantly decreased the incorporation of tritiated D-mannose and D-glucosamine into L1210 ascites leukemia cell glycoproteins at concentrations which affected the biosynthesis of proteins minimally. Mice receiving inoculations of L1210 cells pretreated with 10 microM tunicamycin in vitro survived nearly twice as long as did mice receiving implants of untreated tumor cells. A nonlethal dose of X-irradiation (350 rads) to mice 24 hr prior to receiving their inoculation of tunicamycin-treated L1210 cells prevented this increase in life span. Thirty-eight % of the long-term surviving mice which received 1 X 10(5) L1210 cells pretreated with 10 microM tunicamycin in vitro were then resistant to a subsequent challenge with 10(6) untreated L1210 ascites cells. Direct i.p. administration of tunicamycin to mice resulted in potent liver toxicity (50% lethal dose, 2.0 mg/kg) which obviated any therapeutic efficacy when administered to L1210 ascites tumor-bearing mice. The administration of nontoxic levels of D-mannose prior to the administration of tunicamycin decreased the toxicity of the antibiotic in vivo and, when combined with D-mannose in vitro, exhibited cytotoxic additivity in terms of the inhibition of L1210 leukemic cell growth. A therapeutic regimen incorporating a 24-hr infusion of the sugar prior to multiple administrations of tunicamycin gave evidence of a small therapeutic response in terms of the survival of tumor-bearing mice. These results suggest that tunicamycin, an inhibitor of glycoprotein biosynthesis, might be able to alter tumor cell growth and immunogenicity provided that host liver toxicity is diminished.

  11. Oxygen radical detoxification enzymes in doxorubicin-sensitive and -resistant P388 murine leukemia cells

    SciTech Connect

    Ramu, A.; Cohen, L.; Glaubiger, D.

    1984-05-01

    One of the proposed mechanisms for the cytotoxic effects of anthracycline compounds suggests that the effect is mediated through the formation of intracellular superoxide radicals. It is therefore possible that doxorubicin resistance is associated with increased intracellular enzyme capacity to convert these superoxide radicals to inactive metabolites. We have measured the relative activities of superoxide dismutase, glutathione peroxidase, and catalase in P388 mouse leukemia cells and in a doxorubicin-resistant subline. Since oxygen-reactive metabolites also play a role in mediating the cytotoxicity of ionizing radiation, the radiosensitivity of both cell lines was also studied. No significant differences in superoxide dismutase activity between these cell lines was observed, indicating that they have a similar capacity to convert superoxide anion radicals to hydrogen peroxide. P388 cells that are resistant to doxorubicin have 1.5 times the glutathione content and 1.5 times the activity of glutathione peroxidase measured in drug-sensitive P388 cells. However, incubation with 1-chloro-2,4-dinitrobenzene, which covalently binds glutathione, had no effect on the sensitivity of either cell line to doxorubicin. Measured catalase activity in drug-resistant P388 cells was one-third of the activity measured in doxorubicin-sensitive P388 cells. The activity of this enzyme was much higher than that of glutathione peroxidase in terms of H/sub 2/O/sub 2/ deactivation in both cell lines. It is therefore unlikely that doxorubicin-resistant P388 cells have an increased ability to detoxify reactive oxygen metabolites when compared to drug-sensitive cells. Doxorubicin-resistant P388 cells were significantly more sensitive to X-irradiation than were drug-sensitive P388 cells. These observations suggest that the difference in catalase activity in these cell lines may be associated with the observed differences in radiosensitivity.

  12. Characterization of a naturally occurring ecotropic receptor that does not facilitate entry of all ecotropic murine retroviruses.

    PubMed

    Eiden, M V; Farrell, K; Warsowe, J; Mahan, L C; Wilson, C A

    1993-07-01

    A fibroblast cell line (MDTF) derived from the feral mouse Mus dunni is resistant to infection by Moloney murine leukemia virus (Mo-MuLV), an ecotropic murine leukemia virus (E-MuLV) (M. R. Lander and S. K. Chattopadadhyay, J. Virol. 52:695-698, 1984). MDTF cells can be infected by other E-MuLVs such as Friend MuLV and Rauscher MuLV, which have been demonstrated to use the same receptor as Mo-MuLV in NIH 3T3 cells (A. Rein and A. Schultz, Virology 136:144-152, 1984). We have now shown that the block to Mo-MuLV infection of MDTF cells occurs at the level of the envelope-receptor interaction. We have cloned the ecotropic receptor cDNA from MDTF cells (dRec) and compared its sequence with that of the NIH 3T3 cell receptor (mRec). Although the deduced dRec and mRec proteins differ at only four amino acid residues, we demonstrate that these changes account for the resistance of MDTF cells to Mo-MuLV infection. Our findings suggest that retroviruses in the same receptor class can exhibit different host ranges due to single amino acid differences in their cellular receptor.

  13. Characterization of a naturally occurring ecotropic receptor that does not facilitate entry of all ecotropic murine retroviruses.

    PubMed Central

    Eiden, M V; Farrell, K; Warsowe, J; Mahan, L C; Wilson, C A

    1993-01-01

    A fibroblast cell line (MDTF) derived from the feral mouse Mus dunni is resistant to infection by Moloney murine leukemia virus (Mo-MuLV), an ecotropic murine leukemia virus (E-MuLV) (M. R. Lander and S. K. Chattopadadhyay, J. Virol. 52:695-698, 1984). MDTF cells can be infected by other E-MuLVs such as Friend MuLV and Rauscher MuLV, which have been demonstrated to use the same receptor as Mo-MuLV in NIH 3T3 cells (A. Rein and A. Schultz, Virology 136:144-152, 1984). We have now shown that the block to Mo-MuLV infection of MDTF cells occurs at the level of the envelope-receptor interaction. We have cloned the ecotropic receptor cDNA from MDTF cells (dRec) and compared its sequence with that of the NIH 3T3 cell receptor (mRec). Although the deduced dRec and mRec proteins differ at only four amino acid residues, we demonstrate that these changes account for the resistance of MDTF cells to Mo-MuLV infection. Our findings suggest that retroviruses in the same receptor class can exhibit different host ranges due to single amino acid differences in their cellular receptor. Images PMID:8510216

  14. The Icsbp locus is a common proviral insertion site in mature B-cell lymphomas/plasmacytomas induced by exogenous murine leukemia virus

    SciTech Connect

    Ma Shiliang; Sorensen, Annette Balle; Kunder, Sandra; Sorensen, Karina Dalsgaard; Quintanilla-Martinez, Leticia; Morris, David W.; Schmidt, Joerg; Pedersen, Finn Skou . E-mail: fsp@mb.au.dk

    2006-09-01

    ICSBP (interferon consensus sequence binding protein)/IRF8 (interferon regulatory factor 8) is an interferon gamma-inducible transcription factor expressed predominantly in hematopoietic cells, and down-regulation of this factor has been observed in chronic myelogenous leukemia and acute myeloid leukemia in man. By screening about 1200 murine leukemia virus (MLV)-induced lymphomas, we found proviral insertions at the Icsbp locus in 14 tumors, 13 of which were mature B-cell lymphomas or plasmacytomas. Only one was a T-cell lymphoma, although such tumors constituted about half of the samples screened. This indicates that the Icsbp locus can play a specific role in the development of mature B-lineage malignancies. Two proviral insertions in the last Icsbp exon were found to act by a poly(A)-insertion mechanism. The remaining insertions were found within or outside Icsbp. Since our results showed expression of Icsbp RNA and protein in all end-stage tumor samples, a simple tumor suppressor function of ICSBP is not likely. Interestingly, proviral insertions at Icsbp have not been reported from previous extensive screenings of mature B-cell lymphomas induced by endogenous MLVs. We propose that ICSBP might be involved in an early modulation of an immune response to exogenous MLVs that might also play a role in proliferation of the mature B-cell lymphomas.

  15. Differential antiviral activity of two TIBO derivatives against the human immunodeficiency and murine leukemia viruses alone and in combination with other anti-HIV agents.

    PubMed

    Buckheit, R W; Germany-Decker, J; Hollingshead, M G; Allen, L B; Shannon, W M; Janssen, P A; Chirigos, M A

    1993-11-01

    R82913 and R86183, two derivatives of tetrahydroimidazo[4,5,1-jk][1,4]-benzodiazepin-2(1H)-thione (TIBO), were found to potently and selectively inhibit the replication and cell killing effects of a panel of biologically diverse laboratory and clinical strains of HIV-1. The two compounds exhibited significant activity in all human cell lines tested, as well as in fresh human peripheral blood lymphocytes and macrophages. One of these two compounds (R82913) was found to significantly inhibit the replication of a murine retrovirus (Rauscher murine leukemia virus) in both UV-XC plaque formation and virus yield reduction assays. R86183, despite differing from R82913 only in the positioning of a single chlorine molecule, was not active against the murine retrovirus but was 10-fold more potent in inhibiting HIV-1 replication. Combination antiviral assays with other reverse transcriptase inhibitors, including AZT, ddC, and carbovir, yielded synergistic anti-HIV activity with both TIBO derivatives. Additive to slightly synergistic results were obtained in combinations with ddI and phosphonoformic acid whereas additive to antagonistic activity was detected in combination with dextran sulfate.

  16. Identification of Protein Instability Determinants in the Carboxy-Terminal Region of c-Myb Removed as a Result of Retroviral Integration in Murine Monocytic Leukemias

    PubMed Central

    Bies, Juraj; Nazarov, Viktor; Wolff, Linda

    1999-01-01

    The c-myb oncogene has been a target of retroviral insertional mutagenesis in murine monocytic leukemias. One mechanism by which c-myb can be activated is through the integration of a retroviral provirus into the central portion of the locus, causing premature termination of c-myb transcription and translation. We had previously shown that a leukemia-specific c-Myb protein, truncated at the site of proviral integration by 248 amino acids, had approximately a fourfold-increased half-life compared to the normal c-Myb protein, due to its ability to escape rapid degradation by the ubiquitin-26S proteasome pathway. Here we provide evidence for the existence of more than one instability determinant in the carboxy-terminal region of the wild-type protein, which appear to act independently of each other. The data were derived from examination of premature termination mutants and deletion mutants of the normal protein, as well as analysis of another carboxy-terminally truncated protein expressed in leukemia. Evidence is provided that one instability determinant is located in the terminal 87 amino acids of the protein and another is located in the vicinity of the internal region that has leucine zipper homology. In leukemias, different degrees of protein stability are attained following proviral integration depending upon how many determinants are removed. Interestingly, although PEST sequences (rich in proline, glutamine, serine, and threonine), often associated with degradation, are found in c-Myb, deletion of PEST-containing regions had no effect on protein turnover. This study provides further insight into how inappropriate expression of c-Myb may contribute to leukemogenesis. In addition, it will facilitate further studies aimed at characterizing the specific role of individual regions of the normal protein in targeting to the 26S proteasome. PMID:9971784

  17. Pronounced Hypoxia in Models of Murine and Human Leukemia: High Efficacy of Hypoxia-Activated Prodrug PR-104

    PubMed Central

    Benito, Juliana; Shi, Yuexi; Szymanska, Barbara; Carol, Hernan; Boehm, Ingrid; Lu, Hongbo; Konoplev, Sergej; Fang, Wendy; Zweidler-McKay, Patrick A.; Campana, Dario; Borthakur, Gautam; Bueso-Ramos, Carlos; Shpall, Elizabeth; Thomas, Deborah A.; Jordan, Craig T.; Kantarjian, Hagop; Wilson, William R.; Lock, Richard; Andreeff, Michael; Konopleva, Marina

    2011-01-01

    Recent studies indicate that interactions between leukemia cells and the bone marrow (BM) microenvironment promote leukemia cell survival and confer resistance to anti-leukemic drugs. There is evidence that BM microenvironment contains hypoxic areas that confer survival advantage to hematopoietic cells. In the present study we investigated whether hypoxia in leukemic BM contributes to the protective role of the BM microenvironment. We observed a marked expansion of hypoxic BM areas in immunodeficient mice engrafted with acute lymphoblastic leukemia (ALL) cells. Consistent with this finding, we found that hypoxia promotes chemoresistance in various ALL derived cell lines. These findings suggest to employ hypoxia-activated prodrugs to eliminate leukemia cells within hypoxic niches. Using several xenograft models, we demonstrated that administration of the hypoxia-activated dinitrobenzamide mustard, PR-104 prolonged survival and decreased leukemia burden of immune-deficient mice injected with primary acute lymphoblastic leukemia cells. Together, these findings strongly suggest that targeting hypoxia in leukemic BM is feasible and may significantly improve leukemia therapy. PMID:21853076

  18. Human and murine APOBEC3s restrict replication of koala retrovirus by different mechanisms.

    PubMed

    Nitta, Takayuki; Ha, Dat; Galvez, Felipe; Miyazawa, Takayuki; Fan, Hung

    2015-08-08

    Koala retrovirus (KoRV) is an endogenous and exogenous retrovirus of koalas that may cause lymphoma. As for many other gammaretroviruses, the KoRV genome can potentially encode an alternate form of Gag protein, glyco-gag. In this study, a convenient assay for assessing KoRV infectivity in vitro was employed: the use of DERSE cells (initially developed to search for infectious xenotropic murine leukemia-like viruses). Using infection of DERSE and other human cell lines (HEK293T), no evidence for expression of glyco-gag by KoRV was found, either in expression of glyco-gag protein or changes in infectivity when the putative glyco-gag reading frame was mutated. Since glyco-gag mediates resistance of Moloney murine leukemia virus to the restriction factor APOBEC3, the sensitivity of KoRV (wt or putatively mutant for glyco-gag) to restriction by murine (mA3) or human APOBEC3s was investigated. Both mA3 and hA3G potently inhibited KoRV infectivity. Interestingly, hA3G restriction was accompanied by extensive G → A hypermutation during reverse transcription while mA3 restriction was not. Glyco-gag status did not affect the results. These results indicate that the mechanisms of APOBEC3 restriction of KoRV by hA3G and mA3 differ (deamination dependent vs. independent) and glyco-gag does not play a role in the restriction.

  19. Effects of diallyl trisulfide on induction of apoptotic death in murine leukemia WEHI-3 cells in vitro and alterations of the immune responses in normal and leukemic mice in vivo.

    PubMed

    Hung, Fang-Ming; Shang, Hung-Sheng; Tang, Nou-Ying; Lin, Jen-Jyh; Lu, Kung-Wen; Lin, Jing-Pin; Ko, Yang-Ching; Yu, Chien-Chih; Wang, Hai-Lung; Liao, Jung-Chi; Lu, Hsu-Feng; Chung, Jing-Gung

    2015-11-01

    Diallyl trisulfide (DATS), a chemopreventive dietary constituent and extracted from garlic, has been shown to against cultured many types of human cancer cell liens but the fate of apoptosis in murine leukemia cells in vitro and immune responses in leukemic mice remain elusive. Herein, we clarified the actions of DATS on growth inhibition of murine leukemia WEHI-3 cells in vitro and used WEHI-3 cells to generate leukemic mice in vivo, following to investigate the effects of DATS in animal model. In in vitro study, DATS induced apoptosis of WEHI-3 cells through the G0/G1 phase arrest and induction of caspase-3 activation. In in vivo study DATS decreased the weight of spleen of leukemia mice but did not affect the spleen weight of normal mice. DATS promoted the immune responses such as promotions of the macrophage phagocytosis and NK cell activities in WEHI-3 leukemic and normal mice. However, DATS only promotes NK cell activities in normal mice. DATS increases the surface markers of CD11b and Mac-3 in leukemia mice but only promoted CD3 in normal mice. In conclusion, the present study indicates that DATS induces cell death through induction of apoptosis in mice leukemia WHEI-3 cells. DATS also promotes immune responses in leukemia and normal mice in vivo.

  20. Limits in virus filtration capability? Impact of virus quality and spike level on virus removal with xenotropic murine leukemia virus.

    PubMed

    Roush, David J; Myrold, Adam; Burnham, Michael S; And, Joseph V; Hughes, Joseph V

    2015-01-01

    Virus filtration (VF) is a key step in an overall viral clearance process since it has been demonstrated to effectively clear a wide range of mammalian viruses with a log reduction value (LRV) > 4. The potential to achieve higher LRV from virus retentive filters has historically been examined using bacteriophage surrogates, which commonly demonstrated a potential of > 9 LRV when using high titer spikes (e.g. 10(10) PFU/mL). However, as the filter loading increases, one typically experiences significant decreases in performance and LRV. The 9 LRV value is markedly higher than the current expected range of 4-5 LRV when utilizing mammalian retroviruses on virus removal filters (Miesegaes et al., Dev Biol (Basel) 2010;133:3-101). Recent values have been reported in the literature (Stuckey et al., Biotech Progr 2014;30:79-85) of LRV in excess of 6 for PPV and XMuLV although this result appears to be atypical. LRV for VF with therapeutic proteins could be limited by several factors including process limits (flux decay, load matrix), virus spike level and the analytical methods used for virus detection (i.e. the Limits of Quantitation), as well as the virus spike quality. Research was conducted using the Xenotropic-Murine Leukemia Virus (XMuLV) for its direct relevance to the most commonly cited document, the International Conference of Harmonization (ICH) Q5A (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Geneva, Switzerland, 1999) for viral safety evaluations. A unique aspect of this work is the independent evaluation of the impact of retrovirus quality and virus spike level on VF performance and LRV. The VF studies used XMuLV preparations purified by either ultracentrifugation (Ultra 1) or by chromatographic processes that yielded a more highly purified virus stock (Ultra 2). Two monoclonal antibodies (Mabs) with markedly different filtration characteristics and with similar levels of

  1. Murine leukemia provirus-mediated activation of the Notch1 gene leads to induction of HES-1 in a mouse T lymphoma cell line, DL-3.

    PubMed

    Lee, J S; Ishimoto, A; Honjo, T; Yanagawa, S

    1999-07-23

    Constitutive activation of Notch signaling is known to be associated with tumorigenesis. In a mouse T lymphoma cell line, DL-3, we found that a murine leukemia provirus was inserted in the Notch1 locus, which led to marked expression of a virus-Notch1 fusion mRNA encoding an intracellular portion of the Notch1 protein. Furthermore, expression and nuclear localization of this constitutively active form of Notch1 protein were confirmed. Corresponding to this finding, the transcription of the hairy/enhancer of split (HES-1) gene, a known target of Notch1 signaling, was elevated in this cell line. A potential role for overexpressed HES-1 in the development of the lymphoma was discussed.

  2. Fv-1 determinants in xenotropic murine leukemia viruses studied with biological assay systems: Isolation of xenotropic virus with N-tropic Fv-1 activity in the cryptic form.

    PubMed Central

    Sakai, K; Narita, H; Adachi, A; Tsuruta, S; Yorifuji, T; Ishimoto, A

    1982-01-01

    By a biological assay system using phenotypically mixed ecotropic and xenotropic murine leukemia viruses, we investigated whether in the virions of a xenotropic virus there is N- or B-tropic Fv-1 determinant in active form. The existence of N-tropic Fv-1 determinant was demonstrated in SL-XT-1 xenotropic virus isolated from the spleen of a 3-month-old SL mouse, and the N-tropic Fv-1 tropism was confirmed by analysis of the phenotypically mixed viruses harvested from clonal SC-1 cells doubly infected with the SL-XT-1 and B-tropic ecotropic viruses. However, neither N- nor B-tropic Fv-1 determinant was demonstrated in any xenotropic viruses isolated from embryo cells of BALB/c, NZB, or DBA/2 mice, or Cas E #1-IU, and xenotropic-like virus isolated from a wild mouse. PMID:6283153

  3. Increased dosage of the chromosome 21 ortholog Dyrk1a promotes megakaryoblastic leukemia in a murine model of Down syndrome.

    PubMed

    Malinge, Sébastien; Bliss-Moreau, Meghan; Kirsammer, Gina; Diebold, Lauren; Chlon, Timothy; Gurbuxani, Sandeep; Crispino, John D

    2012-03-01

    Individuals with Down syndrome (DS; also known as trisomy 21) have a markedly increased risk of leukemia in childhood but a decreased risk of solid tumors in adulthood. Acquired mutations in the transcription factor-encoding GATA1 gene are observed in nearly all individuals with DS who are born with transient myeloproliferative disorder (TMD), a clonal preleukemia, and/or who develop acute megakaryoblastic leukemia (AMKL). Individuals who do not have DS but bear germline GATA1 mutations analogous to those detected in individuals with TMD and DS-AMKL are not predisposed to leukemia. To better understand the functional contribution of trisomy 21 to leukemogenesis, we used mouse and human cell models of DS to reproduce the multistep pathogenesis of DS-AMKL and to identify chromosome 21 genes that promote megakaryoblastic leukemia in children with DS. Our results revealed that trisomy for only 33 orthologs of human chromosome 21 (Hsa21) genes was sufficient to cooperate with GATA1 mutations to initiate megakaryoblastic leukemia in vivo. Furthermore, through a functional screening of the trisomic genes, we demonstrated that DYRK1A, which encodes dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A, was a potent megakaryoblastic tumor-promoting gene that contributed to leukemogenesis through dysregulation of nuclear factor of activated T cells (NFAT) activation. Given that calcineurin/NFAT pathway inhibition has been implicated in the decreased tumor incidence in adults with DS, our results show that the same pathway can be both proleukemic in children and antitumorigenic in adults.

  4. Molecular evidence of anti-leukemia activity of gypenosides on human myeloid leukemia HL-60 cells in vitro and in vivo using a HL-60 cells murine xenograft model.

    PubMed

    Lin, Jen-Jyh; Hsu, Hui-Ying; Yang, Jai-Sing; Lu, Kung-Wen; Wu, Rick Sai-Chuen; Wu, King-Chuen; Lai, Tung-Yuan; Chen, Po-Yuan; Ma, Chia-Yu; Wood, W Gibson; Chung, Jing-Gung

    2011-09-15

    We have shown that gypenosides (Gyp) induced cell cycle arrest and apoptosis in many human cancer cell lines. However, there are no reports showing that show Gyp acts on human leukemia HL-60 cells in vitro and in a murine xenograft model in vivo. In the present study effects of Gyp on cell morphological changes and viability, cell cycle arrest and induction of apoptosis in vitro and effects on Gyp in an in vivo murine xenograft model. Results indicated that Gyp induced morphological changes, decreased cell viability, induced G0/G1 arrest, DNA fragmentation and apoptosis (sub-G1 phase) in HL-60 cells. Gyp increased reactive oxygen species production and Ca(2+) levels but reduced mitochondrial membrane potential in a dose- and time-dependent manner. Gyp also changed one of the primary indicators of endoplasmic reticulum (ER) stress due to the promotion of ATF6-α and ATF4-α associated with Ca(2+) release. Gyp reduced the ratio of Bcl-2 to Bax due to an increase in the pro-apoptotic protein Bax and inhibited levels of the anti-apoptotic protein Bcl-2. Oral consumption of Gyp reduced tumor size of HL-60 cell xenograft mode mice in vivo. These results provide new information on understanding mechanisms by which Gyp induces cell cycle arrest and apoptosis in vitro and in vivo. Copyright © 2011 Elsevier GmbH. All rights reserved.

  5. Cellular and species resistance to murine amphotropic, gibbon ape, and feline subgroup C leukemia viruses is strongly influenced by receptor expression levels and by receptor masking mechanisms.

    PubMed

    Tailor, C S; Nouri, A; Kabat, D

    2000-10-01

    Chinese hamster ovary (CHO) cells are resistant to infections by gibbon ape leukemia virus (GALV) and amphotropic murine leukemia virus (A-MLV) unless they are pretreated with tunicamycin, an inhibitor of N-linked glycosylation. These viruses use the related sodium-phosphate symporters Pit1 and Pit2, respectively, as receptors in nonhamster cells, and evidence has suggested that the corresponding transporters of CHO cells may be masked by tunicamycin-sensitive secreted inhibitors. Although the E36 line of Chinese hamster cells was reported to secrete the putative Pit2 inhibitor and to be sensitive to the inhibitory CHO factors, E36 cells are highly susceptible to both GALV and A-MLV in the absence of tunicamycin. Moreover, expression of E36 Pit2 in CHO cells conferred tunicamycin-independent susceptibilities to both viruses. Based on the latter results, it was suggested that E36 Pit2 must functionally differ from the endogenous Pit2 of CHO cells. To test these ideas, we analyzed the receptor properties of CHO Pit1 and Pit2 in CHO cells. Surprisingly, and counterintuitively, transfection of a CHO Pit2 expression vector into CHO cells conferred strong susceptibility to both GALV and A-MLV, and similar overexpression of CHO Pit1 conferred susceptibility to GALV. Thus, CHO Pit2 is a promiscuous functional receptor for both viruses, and CHO Pit1 is a functional receptor for GALV. Similarly, we found that the natural resistance of Mus dunni tail fibroblasts to subgroup C feline leukemia viruses (FeLV-C) was eliminated simply by overexpression of the endogenous FeLV-C receptor homologue. These results demonstrate a novel and simple method to unmask latent retroviral receptor activities that occur in some cells. Specifically, resistances to retroviruses that are caused by subthreshold levels of receptor expression or by stoichiometrically limited masking or interference mechanisms can be efficiently overcome simply by overexpressing the endogenous receptors in the same

  6. Phylogeny-Directed Search for Murine Leukemia Virus-Like Retroviruses in Vertebrate Genomes and in Patients Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Prostate Cancer

    PubMed Central

    Blomberg, Jonas; Sheikholvaezin, Ali; Elfaitouri, Amal; Blomberg, Fredrik; Sjösten, Anna; Mattson Ulfstedt, Johan; Pipkorn, Rüdiger; Källander, Clas; Öhrmalm, Christina; Sperber, Göran

    2011-01-01

    Gammaretrovirus-like sequences occur in most vertebrate genomes. Murine Leukemia Virus (MLV) like retroviruses (MLLVs) are a subset, which may be pathogenic and spread cross-species. Retroviruses highly similar to MLLVs (xenotropic murine retrovirus related virus (XMRV) and Human Mouse retrovirus-like RetroViruses (HMRVs)) reported from patients suffering from prostate cancer (PC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) raise the possibility that also humans have been infected. Structurally intact, potentially infectious MLLVs occur in the genomes of some mammals, especially mouse. Mouse MLLVs contain three major groups. One, MERV G3, contained MLVs and XMRV/HMRV. Its presence in mouse DNA, and the abundance of xenotropic MLVs in biologicals, is a source of false positivity. Theoretically, XMRV/HMRV could be one of several MLLV transspecies infections. MLLV pathobiology and diversity indicate optimal strategies for investigating XMRV/HMRV in humans and raise ethical concerns. The alternatives that XMRV/HMRV may give a hard-to-detect “stealth” infection, or that XMRV/HMRV never reached humans, have to be considered. PMID:22315600

  7. Characterization of structural and immunological properties of specific domains of Friend ecotropic and dual-tropic murine leukemia virus gp70s.

    PubMed Central

    Pinter, A; Honnen, W J

    1984-01-01

    A detailed comparison of the gp70 proteins of cloned ecotropic Friend murine leukemia virus (FLV) and dual-tropic Friend mink focus-forming virus (FrMCF) was performed by analyzing the structural and immunological properties of amino- and carboxy-terminal domains of these molecules generated upon controlled trypsinization. The two gp70s gave characteristic fragmentation patterns; the amino-terminal fragments of FrMCF gp70 were smaller than the corresponding fragments of FLV and contained a trypsin site which resulted in a 19,000-dalton amino-terminal fragment not observed for FLV, whereas both molecules yielded an identically sized carboxy-terminal fragment. All amino-terminal fragments of both gp70 molecules contained an endo H-sensitive oligosaccharide chain; for FrMCF, a second endo H-sensitive carbohydrate was present as well at a carboxy-terminal site for approximately 50% of the molecules. Several aspects of the disulfide interactions of the two gp70s were conserved; in both cases the carboxy-terminal fragments were disulfide bonded to p15(E), there were no disulfide bonds between amino- and carboxy-terminal fragments, and the amino-terminal fragments exhibited a significant increase in mobility upon analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. Analysis of the immunoreactivity of the different domains of the proteins by immunoprecipitation of the fragments with antisera prepared against xenotropic murine leukemia virus and feline leukemia virus gp70s indicated major differences in antigenicity for the amino-terminal domains of FLV and FrMCF gp70, whereas the carboxy-terminal domains were immunologically conserved. Similar analyses with antibodies specific for p15(E) and Pr15(E) demonstrate that these components are conserved as well. These data provide direct evidence that p15(E) and the C-terminal gp70 domain of FrMCF gp70 are related to the corresponding regions of the ecotropic FLV parent and indicate

  8. Inhibition of Pol I transcription treats murine and human AML by targeting the leukemia-initiating cell population

    PubMed Central

    Nguyen, Nhu-Y N.; Fong, Chun Yew; Sornkom, Jirawas; Wall, Meaghan; Pavy, Megan; Cullinane, Carleen; Diesch, Jeannine; Devlin, Jennifer R.; Sanij, Elaine; Quin, Jaclyn; Poortinga, Gretchen; Verbrugge, Inge; Baker, Adele; Drygin, Denis; Powell, Jason A.; Johnstone, Ricky W.; Guthridge, Mark A.; Wei, Andrew; McArthur, Grant A.; Pearson, Richard B.

    2017-01-01

    Despite the development of novel drugs, the prospects for many patients with acute myeloid leukemia (AML) remain dismal. This study reveals that the selective inhibitor of RNA polymerase I (Pol I) transcription, CX-5461, effectively treats aggressive AML, including mixed-lineage leukemia-driven AML, and outperforms standard chemotherapies. In addition to the previously characterized mechanism of action of CX-5461 (ie, the induction of p53-dependent apoptotic cell death), the inhibition of Pol I transcription also demonstrates potent efficacy in p53null AML in vivo. This significant survival advantage in both p53WT and p53null leukemic mice treated with CX-5461 is associated with activation of the checkpoint kinases 1/2, an aberrant G2/M cell-cycle progression and induction of myeloid differentiation of the leukemic blasts. The ability to target the leukemic-initiating cell population is thought to be essential for lasting therapeutic benefit. Most strikingly, the acute inhibition of Pol I transcription reduces both the leukemic granulocyte-macrophage progenitor and leukemia-initiating cell (LIC) populations, and suppresses their clonogenic capacity. This suggests that dysregulated Pol I transcription is essential for the maintenance of their leukemia-initiating potential. Together, these findings demonstrate the therapeutic utility of this new class of inhibitors to treat highly aggressive AML by targeting LICs. PMID:28283481

  9. Inhibition of Pol I transcription treats murine and human AML by targeting the leukemia-initiating cell population.

    PubMed

    Hein, Nadine; Cameron, Donald P; Hannan, Katherine M; Nguyen, Nhu-Y N; Fong, Chun Yew; Sornkom, Jirawas; Wall, Meaghan; Pavy, Megan; Cullinane, Carleen; Diesch, Jeannine; Devlin, Jennifer R; George, Amee J; Sanij, Elaine; Quin, Jaclyn; Poortinga, Gretchen; Verbrugge, Inge; Baker, Adele; Drygin, Denis; Harrison, Simon J; Rozario, James D; Powell, Jason A; Pitson, Stuart M; Zuber, Johannes; Johnstone, Ricky W; Dawson, Mark A; Guthridge, Mark A; Wei, Andrew; McArthur, Grant A; Pearson, Richard B; Hannan, Ross D

    2017-05-25

    Despite the development of novel drugs, the prospects for many patients with acute myeloid leukemia (AML) remain dismal. This study reveals that the selective inhibitor of RNA polymerase I (Pol I) transcription, CX-5461, effectively treats aggressive AML, including mixed-lineage leukemia-driven AML, and outperforms standard chemotherapies. In addition to the previously characterized mechanism of action of CX-5461 (ie, the induction of p53-dependent apoptotic cell death), the inhibition of Pol I transcription also demonstrates potent efficacy in p53null AML in vivo. This significant survival advantage in both p53WT and p53null leukemic mice treated with CX-5461 is associated with activation of the checkpoint kinases 1/2, an aberrant G2/M cell-cycle progression and induction of myeloid differentiation of the leukemic blasts. The ability to target the leukemic-initiating cell population is thought to be essential for lasting therapeutic benefit. Most strikingly, the acute inhibition of Pol I transcription reduces both the leukemic granulocyte-macrophage progenitor and leukemia-initiating cell (LIC) populations, and suppresses their clonogenic capacity. This suggests that dysregulated Pol I transcription is essential for the maintenance of their leukemia-initiating potential. Together, these findings demonstrate the therapeutic utility of this new class of inhibitors to treat highly aggressive AML by targeting LICs. © 2017 by The American Society of Hematology.

  10. A Detailed Protocol for Characterizing the Murine C1498 Cell Line and its Associated Leukemia Mouse Model

    PubMed Central

    Mopin, Alexia; Driss, Virginie; Brinster, Carine

    2016-01-01

    The intravenous injection of C1498 cells into syngeneic or congenic mice has been performed since 1941. These injections result in the development of acute leukemia. However, the nature of this disease has not been well documented in the literature. Here, we provide a technical protocol for characterizing C1498 cells in vitro and for determining the nature of the induced leukemia in vivo. The first part of this procedure is focused on determining the hematopoietic lineage and the stage of differentiation of cultured C1498 cells. To achieve this, multi-parametric flow cytometric staining is used to detect hematopoietic cell markers. Immunofluorescence microscopy, cytochemistry and a May-Grünwald Giemsa staining are then performed to assess the expression of myeloperoxidase, the activity of esterases and cellular morphology, respectively. The second part of this protocol is dedicated to describing the leukemia disease that is induced in vivo. The latter can be achieved by determining the frequencies of leukemic and inherent cells in the blood, hematopoietic organs (e.g., bone marrow and spleen) and non-lymphoid tissues (e.g., the liver and lungs) using specific staining and flow cytometry analyses. The nature of the leukemia is then confirmed using May-Grünwald Giemsa staining and staining for specific esterases in the bone marrow. Here, we present the results that were obtained using this protocol in age-matched C1498- and PBS-injected mice. PMID:27768040

  11. Genetic control of radiation leukemia virus-induced tumorigenesis. I. Role of the major murine histocompatibility complex, H-2

    PubMed Central

    1977-01-01

    Resistance to radiation leukemia virus-induced leukemogenesis is associated with the H-2D region of the H-2 complex, or with closely linked loci. The H-2Dd allele confers resistance ot the disease, while the H-2D-Q and H-2Ds alleles are associated with susceptibility. It is not clear whether Ir genes, or an alternative mechanism are responsible for the observed H-2-linked resistance to the disease. PMID:197195

  12. Targeting JAK1/2 and mTOR in murine xenograft models of Ph-like acute lymphoblastic leukemia

    PubMed Central

    Maude, Shannon L.; Tasian, Sarah K.; Vincent, Tiffaney; Hall, Junior W.; Sheen, Cecilia; Roberts, Kathryn G.; Seif, Alix E.; Barrett, David M.; Chen, I-Ming; Collins, J. Racquel; Mullighan, Charles G.; Hunger, Stephen P.; Harvey, Richard C.; Willman, Cheryl L.; Fridman, Jordan S.; Loh, Mignon L.; Grupp, Stephan A.

    2012-01-01

    CRLF2 rearrangements, JAK1/2 point mutations, and JAK2 fusion genes have been identified in Philadelphia chromosome (Ph)–like acute lymphoblastic leukemia (ALL), a recently described subtype of pediatric high-risk B-precursor ALL (B-ALL) which exhibits a gene expression profile similar to Ph-positive ALL and has a poor prognosis. Hyperactive JAK/STAT and PI3K/mammalian target of rapamycin (mTOR) signaling is common in this high-risk subset. We, therefore, investigated the efficacy of the JAK inhibitor ruxolitinib and the mTOR inhibitor rapamycin in xenograft models of 8 pediatric B-ALL cases with and without CRLF2 and JAK genomic lesions. Ruxolitinib treatment yielded significantly lower peripheral blast counts compared with vehicle (P < .05) in 6 of 8 human leukemia xenografts and lower splenic blast counts (P < .05) in 8 of 8 samples. Enhanced responses to ruxolitinib were observed in samples harboring JAK-activating lesions and higher levels of STAT5 phosphorylation. Rapamycin controlled leukemia burden in all 8 B-ALL samples. Survival analysis of 2 representative B-ALL xenografts demonstrated prolonged survival with rapamycin treatment compared with vehicle (P < .01). These data demonstrate preclinical in vivo efficacy of ruxolitinib and rapamycin in this high-risk B-ALL subtype, for which novel treatments are urgently needed, and highlight the therapeutic potential of targeted kinase inhibition in Ph-like ALL. PMID:22955920

  13. Targeting JAK1/2 and mTOR in murine xenograft models of Ph-like acute lymphoblastic leukemia.

    PubMed

    Maude, Shannon L; Tasian, Sarah K; Vincent, Tiffaney; Hall, Junior W; Sheen, Cecilia; Roberts, Kathryn G; Seif, Alix E; Barrett, David M; Chen, I-Ming; Collins, J Racquel; Mullighan, Charles G; Hunger, Stephen P; Harvey, Richard C; Willman, Cheryl L; Fridman, Jordan S; Loh, Mignon L; Grupp, Stephan A; Teachey, David T

    2012-10-25

    CRLF2 rearrangements, JAK1/2 point mutations, and JAK2 fusion genes have been identified in Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL), a recently described subtype of pediatric high-risk B-precursor ALL (B-ALL) which exhibits a gene expression profile similar to Ph-positive ALL and has a poor prognosis. Hyperactive JAK/STAT and PI3K/mammalian target of rapamycin (mTOR) signaling is common in this high-risk subset. We, therefore, investigated the efficacy of the JAK inhibitor ruxolitinib and the mTOR inhibitor rapamycin in xenograft models of 8 pediatric B-ALL cases with and without CRLF2 and JAK genomic lesions. Ruxolitinib treatment yielded significantly lower peripheral blast counts compared with vehicle (P < .05) in 6 of 8 human leukemia xenografts and lower splenic blast counts (P < .05) in 8 of 8 samples. Enhanced responses to ruxolitinib were observed in samples harboring JAK-activating lesions and higher levels of STAT5 phosphorylation. Rapamycin controlled leukemia burden in all 8 B-ALL samples. Survival analysis of 2 representative B-ALL xenografts demonstrated prolonged survival with rapamycin treatment compared with vehicle (P < .01). These data demonstrate preclinical in vivo efficacy of ruxolitinib and rapamycin in this high-risk B-ALL subtype, for which novel treatments are urgently needed, and highlight the therapeutic potential of targeted kinase inhibition in Ph-like ALL.

  14. Unraveling graft-versus-host disease and graft-versus-leukemia responses using TCR Vβ spectratype analysis in a murine bone marrow transplantation model.

    PubMed

    Fanning, Stacey L; Zilberberg, Jenny; Stein, Johann; Vazzana, Kristin; Berger, Stephanie A; Korngold, Robert; Friedman, Thea M

    2013-01-01

    The optimum use of allogeneic blood and marrow transplantation (BMT) as a curative therapy for hematological malignancies lies in the successful separation of mature donor T cells that are host reactive and induce graft-versus-host disease (GVHD) from those that are tumor reactive and mediate graft-versus-leukemia (GVL) effects. To study whether this separation was possible in an MHC-matched murine BMT model (B10.BR→CBA) with a CBA-derived myeloid leukemia line, MMC6, we used TCR Vβ CDR3-size spectratype analysis to first show that the Vβ13 family was highly skewed in the B10.BR anti-MMC6 CD8(+) T cell response but not in the alloresponse against recipient cells alone. Transplantation of CD8(+)Vβ13(+) T cells at the dose equivalent of their constituency in 1 × 10(7) CD8(+) T cells, a dose that had been shown to mediate lethal GVHD in recipient mice, induced a slight GVL response with no concomitant GVHD. Increasing doses of CD8(+)Vβ13(+) T cells led to more significant GVL responses but also increased GVHD symptoms and associated mortality. Subsequent spectratype analysis of GVHD target tissues revealed involvement of gut-infiltrating CD8(+)Vβ13(+) T cells accounting for the observed in vivo effects. When BMT recipients were given MMC6-presensitized CD8(+)Vβ13(+) T cells, they displayed a significant GVL response with minimal GVHD. Spectratype analysis of tumor-presensitized, gut-infiltrating CD8(+)Vβ13(+) T cells showed preferential usage of tumor-reactive CDR3-size lengths, and these cells expressed increased effector memory phenotype (CD44(+)CD62L(-/lo)). Thus, Vβ spectratyping can identify T cells involved in antihost and antitumor reactivity and tumor presensitization can aid in the separation of GVHD and GVL responses.

  15. Activation of PPARγ by endogenous prostaglandin J2 mediates the antileukemic effect of selenium in murine leukemia.

    PubMed

    Finch, Emily R; Tukaramrao, Diwakar B; Goodfield, Laura L; Quickel, Michael D; Paulson, Robert F; Prabhu, K Sandeep

    2017-03-30

    Supplementation with nontoxic doses of micronutrient selenium has been shown to alleviate chronic myelogenous leukemia (CML) via the elimination of leukemia stem cells (LSCs) in mice. This treatment provides a new and novel method for eliminating the LSCs that are otherwise not targeted by existing therapies. The antileukemic effect of selenium was dependent on the production of endogenous cyclopentenone prostaglandins (CyPGs), Δ-12 prostaglandin J2 (Δ(12)-PGJ2), and 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2). Here, we show that these endogenous CyPGs, produced by mice maintained on selenium-supplemented diets, alleviate the symptoms of CML through their ability to activate the nuclear hormone receptor, peroxisome proliferator activated receptor γ (PPARγ). GW9662, a potent PPARγ antagonist, blocked the antileukemic effect of selenium supplementation by significantly reducing CyPGs. This effect was mediated by an increase in 15-prostaglandin dehydrogenase (15-Pgdh) activity, which oxidizes and inactivates Δ(12)-PGJ2 and 15d-PGJ2 In contrast, treatment with the PPARγ agonist pioglitazone mimicked selenium supplementation. This treatment led to decreased 15-Pgdh activity and increased CyPG levels, which inhibited CML progression. Selenium-dependent activation of PPARγ mediated by endogenous CyPGs decreased Stat5 expression leading to the downregulation of Cited2, a master regulator of LSC quiescence. These studies suggest a potential role for selenium supplementation as an adjuvant therapy in CML. © 2017 by The American Society of Hematology.

  16. Targeting of Murine Leukemia Virus Gag to the Plasma Membrane Is Mediated by PI(4,5)P2/PS and a Polybasic Region in the Matrix ▿

    PubMed Central

    Hamard-Peron, E.; Juillard, F.; Saad, J. S.; Roy, C.; Roingeard, P.; Summers, M. F.; Darlix, J.-L.; Picart, C.; Muriaux, D.

    2010-01-01

    Membrane targeting of the human immunodeficiency virus Gag proteins is dependent on phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2] located in the plasma membrane. In order to determine if evolutionarily distant retroviral Gag proteins are targeted by a similar mechanism, we generated mutants of the matrix (MA) domain of murine leukemia virus (MuLV) Gag, examined their binding to membrane models in vitro, and analyzed their phenotypes in cell culture. In vitro, we showed that MA bound all the phosphatidylinositol phosphates with significant affinity but displayed a strong specificity for PI(4,5)P2 only if enhanced by phosphatidylserine. Mutations in the polybasic region in MA dramatically reduced this affinity. In cells, virus production was strongly impaired by PI(4,5)P2 depletion under conditions of 5ptaseIV overexpression, and mutations in the MA polybasic region altered Gag localization, membrane binding, and virion production. Our results suggest that the N-terminal polybasic cluster of MA is essential for Gag targeting to the plasma membrane. The binding of the MA domain to PI(4,5)P2 appears to be a conserved feature among retroviruses despite the fact that the MuLV-MA domain is structurally different from that of human immunodeficiency virus types 1 and 2 and lacks a readily identifiable PI(4,5)P2 binding cleft. PMID:19828619

  17. Highly Efficient Transfer of Chromosomes to a Broad Range of Target Cells Using Chinese Hamster Ovary Cells Expressing Murine Leukemia Virus-Derived Envelope Proteins

    PubMed Central

    Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

    2016-01-01

    Microcell-mediated chromosome transfer (MMCT) is an essential step for introducing chromosomes from donor cells to recipient cells. MMCT allows not only for genetic/epigenetic analysis of specific chromosomes, but also for utilization of human and mouse artificial chromosomes (HACs/MACs) as gene delivery vectors. Although the scientific demand for genome scale analyses is increasing, the poor transfer efficiency of the current method has hampered the application of chromosome engineering technology. Here, we developed a highly efficient chromosome transfer method, called retro-MMCT, which is based on Chinese hamster ovary cells expressing envelope proteins derived from ecotropic or amphotropic murine leukemia viruses. Using this method, we transferred MACs to NIH3T3 cells with 26.5 times greater efficiency than that obtained using the conventional MMCT method. Retro-MMCT was applicable to a variety of recipient cells, including embryonic stem cells. Moreover, retro-MMCT enabled efficient transfer of MAC to recipient cells derived from humans, monkeys, mice, rats, and rabbits. These results demonstrate the utility of retro-MMCT for the efficient transfer of chromosomes to various types of target cell. PMID:27271046

  18. Complementation of a primer binding site-impaired murine leukemia virus-derived retroviral vector by a genetically engineered tRNA-like primer.

    PubMed Central

    Lund, A H; Duch, M; Lovmand, J; Jørgensen, P; Pedersen, F S

    1997-01-01

    Reverse transcription of retroviral genomes is primed by a tRNA annealed to an 18-nucleotide primer binding site. Here, we present a primer complementation system to study molecular interaction of the replication machinery with the primer and primer binding site in vivo. Introduction of eight base substitutions into the primer binding site of a murine leukemia virus-based vector allowed efficient RNA encapsidation but resulted in severely reduced vector replication capacity. Replication was restored upon complementation with a synthetic gene designed to encode a complementary tRNA-like primer, but not with a noncomplementary tRNA-like molecule. The engineered primer was shown to be involved in both the initiation of first-strand synthesis and second-strand transfer. These results provide an in vivo demonstration that the retroviral replication machinery may recognize sequence complementarity rather than actual primer binding site and 3' primer sequences. Use of mutated primer binding site vectors replicating via engineered primers may add additional control features to retroviral gene transfer technology. PMID:8995641

  19. Restoration of adenylate cyclase responsiveness in murine myeloid leukemia permits inhibition of proliferation by hormone. Butyrate augments catalytic activity of adenylate cyclase.

    PubMed

    Inhorn, L; Fleming, J W; Klingberg, D; Gabig, T G; Boswell, H S

    1988-04-01

    Mechanisms of leukemic cell clonal dominance may include aberrations of transmembrane signaling. In particular, neoplastic transformation has been associated with reduced capacity for hormone-stimulated adenylate cyclase activity. In the present study, prostaglandin E, a hormonal activator of adenylate cyclase that has antiproliferative activity in myeloid cells, and cholera toxin, an adenylate cyclase agonist that functions at a postreceptor site by activating the adenylate cyclase stimulatory GTP-binding protein (Gs), were studied for antiproliferative activity in two murine myeloid cell lines. FDC-P1, an interleukin 3 (IL 3)-dependent myeloid cell line and a tumorigenic IL 3-independent subline, FI, were resistant to these antiproliferative agents. The in vitro ability of the "differentiation" agent, sodium butyrate, to reverse their resistance to adenylate cyclase agonists was studied. The antiproliferative action of butyrate involved augmentation of transmembrane adenylate cyclase activity. Increased adenylate cyclase catalyst activity was the primary alteration of this transmembrane signaling group leading to the functional inhibitory effects on leukemia cells, although alterations in regulatory G-proteins appear to play a secondary role.

  20. Distinct roles of enhancer nuclear factor 1 (NF1) sites in plasmacytoma and osteopetrosis induction by Akv1-99 murine leukemia virus

    SciTech Connect

    Sorensen, Karina Dalsgaard; Sorensen, Annette Balle; Quintanilla-Martinez, Leticia; Kunder, Sandra; Schmidt, Joerg; Pedersen, Finn Skou . E-mail: fsp@mb.au.dk

    2005-04-10

    Murine leukemia viruses (MLVs) can be lymphomagenic and bone pathogenic. In this work, the possible roles of two distinct proviral enhancer nuclear factor 1 (NF1) binding sites in osteopetrosis and tumor induction by B-lymphomagenic Akv1-99 MLV were investigated. Akv1-99 and mutants either with NF1 site 1, NF1 site 2 or both sites disrupted induced tumors (plasma cell proliferations by histopathology) with remarkably similar incidence and mean latency in inbred NMRI mice. Clonal immunoglobulin gene rearrangement detection, by Southern analysis, confirmed approximately half of the tumors induced by each virus to be plasmacytomas while the remaining lacked detectable clonally rearranged Ig genes and were considered polyclonal; a demonstration that enhancer NF1 sites are dispensable for plasmacytoma induction by Akv1-99. In contrast, X-ray analysis revealed significant differences in osteopetrosis induction by the four viruses strongly indicating that NF1 site 2 is critical for viral bone pathogenicity, whereas NF1 site 1 is neutral or moderately inhibitory. In conclusion, enhancer NF1 sites are major determinants of osteopetrosis induction by Akv1-99 without significant influence on viral oncogenicity.

  1. The effects on the expression of. beta. -lactamase by targeted insertion of a Kirsten murine leukemia virus variant into the coding region of the gene

    SciTech Connect

    Dias-Ferrao, V.P.T.

    1988-01-01

    The product of this plasmid gene protects bacteria from the antibiotic, ampicillin. When the Kirsten murine leukemia virus variant DNA (MuLV-K-Vd) was inserted into the Pst 1 site of the {beta}-lactamase gene, the transformed bacteria (E. coli, DH5) were resistant to ampicillin. The purpose of this study is to explain the presence of a functional {beta}-lactamase gene with additional nucleotides inserted into the coding region of the gene. The recombinant plasmid codes for a functional {beta}-lactamase. Northern blot analysis of RNA using a {sup 32}P-labelled 16{sup mer} oligonucleotide as a probe revealed the {beta}-lactamase transcript from the recombinant plasmid to be shorter than the transcript from the wild-type {beta}-lactamase gene. Also, greater levels of {beta}-lactamase mRNA were present in cells containing the recombinant plasmid compared to those containing the wild-type plasmid. Restriction enzyme mapping indicated that the 3{prime} end of MuLV-K-Vd insert contains sequences of {beta}-lactamase. Nucleic acid sequencing substantiated the hybridization data that {beta}-lactamase sequences are present in the 3{prime} end of MuLV-K-Vd. However, exact sequence homology is not evident.

  2. Depletion of endogenous tumor-associated regulatory T cells improves the efficacy of adoptive cytotoxic T-cell immunotherapy in murine acute myeloid leukemia.

    PubMed

    Zhou, Qing; Bucher, Christoph; Munger, Meghan E; Highfill, Steven L; Tolar, Jakub; Munn, David H; Levine, Bruce L; Riddle, Megan; June, Carl H; Vallera, Daniel A; Weigel, Brenda J; Blazar, Bruce R

    2009-10-29

    Tumor-induced immune suppression can permit tumor cells to escape host immune resistance. To elucidate host factors contributing to the poor response of adoptively transferred tumor-reactive cytotoxic T lymphocytes (CTLs), we used a systemic model of murine acute myeloid leukemia (AML). AML progression resulted in a progressive regulatory T-cell (Treg) accumulation in disease sites. The adoptive transfer of in vitro-generated, potently lytic anti-AML-reactive CTLs failed to reduce disease burden or extend survival. Compared with non-AML-bearing hosts, transferred CTLs had reduced proliferation in AML sites of metastases. Treg depletion by a brief course of interleukin-2 diphtheria toxin (IL-2DT) transiently reduced AML disease burden but did not permit long-term survival. In contrast, IL-2DT prevented anti-AML CTL hypoproliferation, increased the number of transferred CTLs at AML disease sites, reduced AML tumor burden, and resulted in long-term survivors that sustained an anti-AML memory response. These data demonstrated that Tregs present at AML disease sites suppress adoptively transferred CTL proliferation, limiting their in vivo expansion, and Treg depletion before CTL transfer can result in therapeutic efficacy in settings of substantial pre-existing tumor burden in which antitumor reactive CTL infusion alone has proven ineffective.

  3. Depletion of endogenous tumor-associated regulatory T cells improves the efficacy of adoptive cytotoxic T-cell immunotherapy in murine acute myeloid leukemia

    PubMed Central

    Zhou, Qing; Bucher, Christoph; Munger, Meghan E.; Highfill, Steven L.; Tolar, Jakub; Munn, David H.; Levine, Bruce L.; Riddle, Megan; June, Carl H.; Vallera, Daniel A.; Weigel, Brenda J.

    2009-01-01

    Tumor-induced immune suppression can permit tumor cells to escape host immune resistance. To elucidate host factors contributing to the poor response of adoptively transferred tumor-reactive cytotoxic T lymphocytes (CTLs), we used a systemic model of murine acute myeloid leukemia (AML). AML progression resulted in a progressive regulatory T-cell (Treg) accumulation in disease sites. The adoptive transfer of in vitro–generated, potently lytic anti–AML-reactive CTLs failed to reduce disease burden or extend survival. Compared with non–AML-bearing hosts, transferred CTLs had reduced proliferation in AML sites of metastases. Treg depletion by a brief course of interleukin-2 diphtheria toxin (IL-2DT) transiently reduced AML disease burden but did not permit long-term survival. In contrast, IL-2DT prevented anti-AML CTL hypoproliferation, increased the number of transferred CTLs at AML disease sites, reduced AML tumor burden, and resulted in long-term survivors that sustained an anti-AML memory response. These data demonstrated that Tregs present at AML disease sites suppress adoptively transferred CTL proliferation, limiting their in vivo expansion, and Treg depletion before CTL transfer can result in therapeutic efficacy in settings of substantial pre-existing tumor burden in which antitumor reactive CTL infusion alone has proven ineffective. PMID:19724059

  4. Ductal variant of prostate adenocarcinoma harbor Xenotropic murine leukemia virus related virus (XMRV) infection: a novel finding in subtype of prostate cancer

    PubMed Central

    Baig, Faraz Ahmed; Mirza, Talat; Hamid, Amna; Syed, Serajuddaula; Jamal, Qamar

    2017-01-01

    Objective Xenotropic murine leukemia virus related virus (XMRV), is the first gammaretrovirus identified a decade ago, in human tissue bearing adenocarcinoma of prostate, followed by several researches documenting little or no prevalence of XMRV in prostate cancer samples. However, the status of XMRV within subtype of prostate adenocarcinoma has not been investigated yet. In this study, we investigated the relationship between XMRV and broad spectrum morphological entities of prostate adenocarcinoma, including acinar, ductal and other rare subtypes. Material and methods The prevalence of XMRV DNA in different histological subtypes of prostate adenocarcinoma was examined after characterizing the tumors into groups, using formalin-fixed, paraffin-embedded tissue samples from newly diagnosed prostate adenocarcinomas and archival prostate cancer tissue from our XMRV case control analysis. Broad-spectrum XMRV DNA amplification was performed by end-point polymerase chain reaction, using commercially available primer set. Results The study included 100 patients with prostate cancer. XMRV DNA was detected in 4 of 8 (50%) ductal adenocarcinomas, exhibiting papillary and cribriform histological features. XMRV DNA was not detected in any other variant of adenocarcinoma including acinar (0/91) and mucinous carcinomas (0/1). Majority of XMRV positive cases were biologically aggressive and present cancer at an early age upon diagnosis. Conclusion Ductal adenocarcinomas demonstrate a significant association of XMRV DNA while other histological variants of prostate adenocarcinoma seem unrelated to XMRV infection. PMID:28861296

  5. Abnormalities induced by the mutant gene, lpr. Patterns of disease and expression of murine leukemia viruses in SJL/J mice homozygous and heterozygous for lpr.

    PubMed

    Morse, H C; Roths, J B; Davidson, W F; Langdon, W Y; Fredrickson, T N; Hartley, J W

    1985-03-01

    SJL/J mice heterozygous or homozygous for the lpr mutation were compared with SJL/J-+/+ mice for longevity, histopathology, antigenic characteristics of lymphocytes and expression of murine leukemia viruses (MuLV). In comparison to +/+ mice, lpr homozygotes had a markedly shortened life span, died with infiltrative pulmonary disease, but little or no renal disease, and expressed high levels of infectious ecotropic MuLV in lymphoid tissues. SJL-lpr/+ mice had a life span intermediate between SJL-+/+ and -lpr/lpr mice, died with lymphomas that histologically resembled the neoplasms of +/+ mice, and sometimes expressed high levels of ecotropic MuLV. The lymphomas of lpr/+ could be transplanted to +/+ recipients in 78% of cases, and continuous in vitro lines were established from some of them. Similar effects on virus expression or lymphoma development were not observed in other strains homozygous or heterozygous for the lpr mutation. These results indicate that the diseases expressed by mice homozygous for the lpr mutation are highly strain-dependent, and that this gene can have an effect in the heterozygous state in SJL mice.

  6. Enhancer mutations of Akv murine leukemia virus inhibit the induction of mature B-cell lymphomas and shift disease specificity towards the more differentiated plasma cell stage

    SciTech Connect

    Sorensen, Karina Dalsgaard; Kunder, Sandra; Quintanilla-Martinez, Leticia; Sorensen, Jonna; Schmidt, Joerg; Pedersen, Finn Skou . E-mail: fsp@mb.au.dk

    2007-05-25

    This study investigates the role of the proviral transcriptional enhancer for B-lymphoma induction by exogenous Akv murine leukemia virus. Infection of newborn inbred NMRI mice with Akv induced 35% plasma cell proliferations (PCPs) (consistent with plasmacytoma), 33% diffuse large B-cell lymphomas, 25% follicular B-cell lymphomas and few splenic marginal zone and small B-cell lymphomas. Deleting one copy of the 99-bp proviral enhancer sequence still allowed induction of multiple B-cell tumor types, although PCPs dominated (77%). Additional mutation of binding sites for the glucocorticoid receptor, Ets, Runx, or basic helix-loop-helix transcription factors in the proviral U3 region, however, shifted disease induction to almost exclusively PCPs, but had no major influence on tumor latency periods. Southern analysis of immunoglobulin rearrangements and ecotropic provirus integration patterns showed that many of the tumors/cell proliferations induced by each virus were polyclonal. Our results indicate that enhancer mutations weaken the ability of Akv to induce mature B-cell lymphomas prior to the plasma cell stage, whereas development of plasma cell proliferations is less dependent of viral enhancer strength.

  7. Volatile isoprenoid constituents of fruits, vegetables and herbs cumulatively suppress the proliferation of murine B16 melanoma and human HL-60 leukemia cells.

    PubMed

    Tatman, Dana; Mo, Huanbiao

    2002-01-25

    Substantial evidence from epidemiological studies supports the inverse association between the intake of fruits, vegetables and other plant products and cancer incidence. Cancer-preventive constituents of fruits and vegetables may inhibit carcinogen activation, enhance carcinogen detoxification, prevent carcinogens from interacting with critical target sites, or impede tumor progression. These activities, however, are achievable only when levels of individual bioactive constituents reach beyond those attainable from a normal balanced diet. Isoprenoids, a broad class of mevalonate-derived phytochemicals ubiquitous in the plant kingdom, suppress the proliferation of tumor cells and the growth of implanted tumors. A search for volatile isoprenoid constituents of food products spanning seven plant families identified 179 isoprenoids. Of these, 41 purchased from commercial sources were screened for efficacy in suppressing the proliferation of murine B16 melanoma cells. Individual isoprenoids suppressed the proliferation of B16 and HL-60 promyelocytic leukemia cells with varying degrees of potency. Cell cycle arrest at the G(0)-G(1) phase and apoptosis account, at least in part, for the suppression. Blends of isoprenoids suppressed B16 and HL-60 cell proliferation with efficacies equal to the sum of the individual impacts. These findings suggest that the cancer-protective property of fruits, vegetables, and related products is partly conferred by the cumulative impact of volatile isoprenoid constituents.

  8. Murine leukemia virus pol gene products: analysis with antisera generated against reverse transcriptase and endonuclease fusion proteins expressed in Escherichia coli

    SciTech Connect

    Hu, S.C.; Court, D.L.; Zweig, M.; Levin, J.G.

    1986-10-01

    The organization of the murine leukemia virus (MuLV) pol gene was investigated by expressing molecular clones containing AKR MuLV reverse transcriptase or endonuclease or both gene segments in Escherichia coli and generating specific antisera against the expressed bacterial proteins. Reaction of these antisera with detergent-disrupted virus precipitated and 80-kilodalton (kDa) protein, the MuLV reverse transcriptase, and a 46-kDa protein which we believe is the viral endonuclease. A third (50-kDa) protein, related to reverse transcriptase, was also precipitated. Bacterial extracts of clones expressing reverse transcriptase and endonuclease sequences competed with the viral 80- and 46-kDa proteins, respectively. These results demonstrate that the antisera are specific for viral reverse transcriptase and endonuclease. Immunoprecipitation of AKR MuLV with antisera prepared against a bacterial protein containing only endonuclease sequences led to the observation that reverse transcriptase and endonuclease can be associated as a complex involving a disulfide bond(s).

  9. Depletion of Dendritic Cells Enhances Susceptibility to Cell-Free Infection of Human T Cell Leukemia Virus Type 1 in CD11c-Diphtheria Toxin Receptor Transgenic Mice

    PubMed Central

    Rahman, Saifur; Manuel, Sharrón L.; Khan, Zafar K.; Wigdahl, Brian; Acheampong, Edward; Tangy, Frederic; Jain, Pooja

    2010-01-01

    Human T cell leukemia virus type 1 (HTLV-1) is associated with two immunologically distinct diseases: HTLV-1–associated myelopathy/tropical spastic paraparesis and adult T cell leukemia. The genesis of these diseases is believed to be associated with the route (mucosa versus blood) and mode (cell-free versus cell-associated) of primary infection as well as the modulation of dendritic cell (DC) functions. To explore the role of DCs during early HTLV-1 infection invivo, we used a chimeric HTLV-1 with a replaced envelope gene from Moloney murine leukemia virus to allow HTLV-1 to fuse with murine cells, which are generally not susceptible to infection with human retroviruses. We also used a CD11c-diphtheria toxin receptor transgenic mouse model system that permits conditional transient depletion of CD11c+ DCs. We infected these transgenic mice with HTLV-1 using both cell-free and cell-associated infection routes in the absence and presence of DCs. The ablation of DCs led to an enhanced susceptibility to infection with cell-free but not cell-associated HTLV-1 in both CD4 and non-CD4 fractions, as measured by the proviral load. Infection with cell-free virus in the absence of DCs was also found to have increased levels of Tax mRNA in the non-CD4 fraction. Moreover, depletion of DCs significantly dampened the cellular immune response (IFN-γ+CD8+ T cells) against both cell-free and cell-associated virus. These results uniquely differentiate the involvement of DCs in early cell-free versus late cell-associated infection of HTLV-1 and highlight a significant aspect of viral immunopathogenesis related to the progression of adult T cell leukemia and HTLV-1–associated myelopathy/tropical spastic paraparesis after the initial infection. PMID:20382884

  10. Stage-specific expression of intracisternal A-particle sequences in murine myelomonocytic leukemia cell lines and normal myelomonocytic differentiation.

    PubMed Central

    Takayama, Y; O'Mara, M A; Spilsbury, K; Thwaite, R; Rowe, P B; Symonds, G

    1991-01-01

    The levels of intracisternal A-particle (IAP) mRNA were analyzed in a variety of myelomonocytic leukemia cell lines, peritoneally derived macrophages, and normal hemopoietic progenitors induced to differentiate. In both normal and leukemic cells, the highest level of IAP message was found in cells at an intermediate stage of myelomonocytic differentiation, namely, the promyelomonocyte. These results indicate that IAP sequence transcription is regulated differentially during myelomonocytic cell development and that in general, the expression pattern is preserved in leukemic cell lines in vitro. In addition, Northern (RNA) analysis detected only type I IAP transcripts as the major IAP message and the expressed IAP subtypes varied in certain cell lines. This is the first comprehensive study of IAP expression in the myelomonocytic lineage and provides a useful system to study the biology of IAPs. Images PMID:1848323

  11. Genetic resistance in Japanese wild mice (Mus musculus molossinus) to an NB-tropic Friend murine leukemia virus.

    PubMed

    Odaka, T; Ikeda, H; Moriwaki, K; Matsuzawa, A; Mizuno, M; Kondo, K

    1978-11-01

    Wild mice (Sk, Hz-Vl, Hz-IV Om, Mol.A, Fu, Te, and Sn) trapped in various areas of Japan were crossed with mice of inbred strains (C57BL/6, C57L, BALB/c, and C57BL/10), and their progeny were infected with NB-tropic Friend nurine leukemia virus. Ten days after infection, the spleens were weighed, examined for macroscopic focal lesions, and assayed for infectious virus by the XC test. Genetic analysis indicated that 4 of 8 mice tested had a dominant gene that suppresses the virus replication; the gene resembles the Fv-4' allele. No mice with the Fv-2' allele were found.

  12. The novel combination of dual mTOR inhibitor AZD2014 and pan-PIM inhibitor AZD1208 inhibits growth in acute myeloid leukemia via HSF pathway suppression.

    PubMed

    Harada, Masako; Benito, Juliana; Yamamoto, Shinichi; Kaur, Surinder; Arslan, Dirim; Ramirez, Santiago; Jacamo, Rodrigo; Platanias, Leonidas; Matsushita, Hiromichi; Fujimura, Tsutomu; Kazuno, Saiko; Kojima, Kensuke; Tabe, Yoko; Konopleva, Marina

    2015-11-10

    Mammalian target of rapamycin (mTOR) signaling is a critical pathway in the biology of acute myeloid leukemia (AML). Proviral integration site for moloney murine leukemia virus (PIM) serine/threonine kinase signaling takes part in various pathways exerting tumorigenic properties. We hypothesized that the combination of a PIM kinase inhibitor with an mTOR inhibitor might have complementary growth-inhibitory effects against AML. The simultaneous inhibition of the PIM kinase by pan-PIM inhibitor AZD1208 and of mTOR by selective mTORC1/2 dual inhibitor AZD2014 exerted anticancer properties in AML cell lines and in cells derived from primary AML samples with or without supportive stromal cell co-culture, leading to suppressed proliferation and increased apoptosis. The combination of AZD1208 and AZD2014 rapidly activated AMPKα, a negative regulator of translation machinery through mTORC1/2 signaling in AML cells; profoundly inhibited AKT and 4EBP1 activation; and suppressed polysome formation. Inhibition of both mTOR and PIM counteracted induction of heat-shock family proteins, uncovering the master negative regulation of heat shock factor 1 (HSF1), the dominant transcription factor controlling cellular stress responses. The novel combination of the dual mTOR inhibitor and pan-PIM inhibitor synergistically inhibited AML growth by effectively reducing protein synthesis through heat shock factor pathway suppression.

  13. Chrysin, a natural and biologically active flavonoid, influences a murine leukemia model in vivo through enhancing populations of T-and B-cells, and promoting macrophage phagocytosis and NK cell cytotoxicity.

    PubMed

    Lin, Chin-Chung; Yu, Chun-Shu; Yang, Jai-Sing; Lu, Chi-Cheng; Chiang, Jo-Hua; Lin, Jing-Pin; Kuo, Chao-Lin; Chung, Jing-Gung

    2012-01-01

    Chrysin (5,7-dihydroxyflavone), a natural and biologically active flavonoid found in plants, possesses many biological activities and anticancer effects. However, there is no available evidence regarding the antileukemia responses to chrysin in a mouse model. We hypothesized that chrysin affects murine WEHI-3 leukemia cells in vitro and in vivo. The present study showed that chrysin at concentrations of 5-50 μM reduced the cell viability in concentration- and time-dependent manners. In an in vivo study, WEHI-3 leukemic BALB/c mice were established in order to determine antileukemia activity of chrysin. Our results revealed that chrysin increased the percentage of CD3 (T-cell maker), CD19 (B-cell maker) and Mac-3 (macrophages) cell surface markers in treated mice as compared with the untreated leukemia group. However, chrysin did not significantly influence the level of CD11b (a monocyte maker) in treated mice. Moreover, there was a significant increase in phagocytosis by macrophages from peripheral blood mononuclear cells, but no effect in those from the peritoneal cavity in leukemic mice after chrysin treatment. Isolated splenocytes from chrysin-treated leukemic mice demonstrated an increase of natural killer (NK) cell cytotoxicity. Based on these observations, chrysin might exhibit antileukemia effects on a murine WEHI-3 cell line-induced leukemia in vivo.

  14. Induction of donor-type chimerism in murine recipients of bone marrow allografts by different radiation regimens currently used in treatment of leukemia patients

    SciTech Connect

    Salomon, O.; Lapidot, T.; Terenzi, A.; Lubin, I.; Rabi, I.; Reisner, Y. )

    1990-11-01

    Three radiation protocols currently used in treatment of leukemia patients before bone marrow transplantation (BMT) were investigated in a murine model (C57BL/6----C3H/HeJ) for BM allograft rejection. These include (a) a single dose of total body irradiation (8.5 Gy TBI delivered at a dose rate of 0.2 Gy/min), (b) fractionated TBI 12 Gy administered in six fractions, 2 Gy twice a day in 3 days, delivered at a dose rate of 0.1 Gy/min, and (c) hyperfractionated TBI (14.4 Gy administered in 12 fractions, 1.2 Gy three times a day in 3 days, delivered at a dose rate of 0.1 Gy/min). Donor-type chimerism 6 to 8 weeks after BMT and hematologic reconstitution on day 12 after BMT found in these groups were compared with results obtained in mice conditioned with 8 Gy TBI delivered at a dose rate of 0.67 Gy/min, routinely used in this murine model. The results in both parameters showed a marked advantage for the single dose 8.5 Gy TBI over all the other treatments. This advantage was found to be equivalent to three- to fourfold increment in the BM inoculum when compared with hyperfractionated radiation, which afforded the least favorable conditions for development of donor-type chimerism. The fractionated radiation protocol was equivalent in its efficacy to results obtained in mice irradiated by single-dose 8 Gy TBI, both of which afforded a smaller but not significant advantage over the hyperfractionated protocol. This model was also used to test the effect of radiation dose rate on the development of donor-type chimerism. A significant enhancement was found after an increase in dose rate from 0.1 to 0.7 Gy/min. Further enhancement could be achieved when the dose rate was increased to 1.3 Gy/min, but survival at this high dose rate was reduced.

  15. Fatty acid metabolism in L1210 murine leukemia cells: differences in modification of fatty acids incorporated into various lipids.

    PubMed

    Burns, C P; Wei, S P; Spector, A A

    1978-10-01

    L1210 leukemia cells can utilize all of the main fatty acids that normally are present in the ascites fluid in which they grow. This finding is consistent with the view that L1210 cells derive most of their fatty acids from the ascites fluid. From 80--90% of each fatty acid was incorporated into cell lipids without structural modification, suggesting that the lipid composition of these cells can be altered by changing the type of fatty acids to which they are exposed. Most importantly, the palmitate that was subsequently incorporated into total cell phospholipids was elongated and desaturated somewhat more than that incorporated into triglycerides. This difference was due primarily to more extensive modification of the palmitate incorporated into the ethanolamine phosphoglycerides fraction. Although there was no difference between total phospholipids and triglycerides with linoleate, more of the linoleate incorporated into ethanolamine phosphoglycerides was elongated and further desaturated than that incorporated into choline phosphoglycerides and triglycerides. These findings indicate fatty acids incorporated into various cell lipid fractions are not structurally modified to the same extent. There appears to be greater modification of fatty acid used for ethanolamine phosphoglyceride synthesis as compared with triglyceride and choline phosphoglyceride synthesis.

  16. Mouse Siglec-1 Mediates trans-Infection of Surface-bound Murine Leukemia Virus in a Sialic Acid N-Acyl Side Chain-dependent Manner*

    PubMed Central

    Erikson, Elina; Wratil, Paul R.; Frank, Martin; Ambiel, Ina; Pahnke, Katharina; Pino, Maria; Azadi, Parastoo; Izquierdo-Useros, Nuria; Martinez-Picado, Javier; Meier, Chris; Schnaar, Ronald L.; Crocker, Paul R.; Reutter, Werner; Keppler, Oliver T.

    2015-01-01

    Siglec-1 (sialoadhesin, CD169) is a surface receptor on human cells that mediates trans-enhancement of HIV-1 infection through recognition of sialic acid moieties in virus membrane gangliosides. Here, we demonstrate that mouse Siglec-1, expressed on the surface of primary macrophages in an interferon-α-responsive manner, captures murine leukemia virus (MLV) particles and mediates their transfer to proliferating lymphocytes. The MLV infection of primary B-cells was markedly more efficient than that of primary T-cells. The major structural protein of MLV particles, Gag, frequently co-localized with Siglec-1, and trans-infection, primarily of surface-bound MLV particles, efficiently occurred. To explore the role of sialic acid for MLV trans-infection at a submolecular level, we analyzed the potential of six sialic acid precursor analogs to modulate the sialylated ganglioside-dependent interaction of MLV particles with Siglec-1. Biosynthetically engineered sialic acids were detected in both the glycolipid and glycoprotein fractions of MLV producer cells. MLV released from cells carrying N-acyl-modified sialic acids displayed strikingly different capacities for Siglec-1-mediated capture and trans-infection; N-butanoyl, N-isobutanoyl, N-glycolyl, or N-pentanoyl side chain modifications resulted in up to 92 and 80% reduction of virus particle capture and trans-infection, respectively, whereas N-propanoyl or N-cyclopropylcarbamyl side chains had no effect. In agreement with these functional analyses, molecular modeling indicated reduced binding affinities for non-functional N-acyl modifications. Thus, Siglec-1 is a key receptor for macrophage/lymphocyte trans-infection of surface-bound virions, and the N-acyl side chain of sialic acid is a critical determinant for the Siglec-1/MLV interaction. PMID:26370074

  17. Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

    PubMed Central

    Ahi, Yadvinder S.; Zhang, Shu; Thappeta, Yashna; Denman, Audrey; Feizpour, Amin; Reinhard, Bjoern; Muriaux, Delphine; Fivash, Matthew J.

    2016-01-01

    ABSTRACT Gammaretroviruses, such as murine leukemia viruses (MLVs), encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag). MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes. PMID:27879338

  18. Evaluation of cellular determinants required for in vitro xenotropic murine leukemia virus-related virus entry into human prostate cancer and noncancerous cells.

    PubMed

    Bhosle, Sushma; Suppiah, Suganthi; Molinaro, Ross; Liang, Yuying; Arnold, Rebecca; Diehl, William; Makarova, Natalia; Blackwell, Jerry; Petros, John; Liotta, Dennis; Hunter, Eric; Ly, Hinh

    2010-07-01

    The newly identified retrovirus-the xenotropic murine leukemia virus-related virus (XMRV)-has recently been shown to be strongly associated with familial prostate cancer in humans (A. Urisman et al., PLoS Pathog. 2:e25, 2006). While that study showed evidence of XMRV infection exclusively in the prostatic stromal fibroblasts, a recent study found XMRV protein antigens mainly in malignant prostate epithelial cells (R. Schlaberg et al., Proc. Natl. Acad. Sci. U. S. A. 106:16351-16356, 2009). To help elucidate the mechanisms behind XMRV infection, we show that prostatic fibroblast cells express Xpr1, a known receptor of XMRV, but its expression is absent in other cell lines of the prostate (i.e., epithelial and stromal smooth muscle cells). We also show that certain amino acid residues located within the predicted extracellular loop (ECL3 and ECL4) sequences of Xpr1 are required for efficient XMRV entry. Although we found strong evidence to support XMRV infection of prostatic fibroblast cell lines via Xpr1, we learned that XMRV was indeed capable of infecting cells that did not necessarily express Xpr1, such as those of the prostatic epithelial and smooth muscle origins. Further studies suggest that the expression of Xpr1 and certain genotypes of the RNASEL gene, which could restrict XMRV infection, may play important roles in defining XMRV tropisms in certain cell types. Collectively, our data reveal important cellular determinants required for XMRV entry into different human prostate cells in vitro, which may provide important insights into the possible role of XMRV as an etiologic agent in human prostate cancer.

  19. Identification of the infected target cell type in spongiform myeloencephalopathy induced by the neurotropic Cas-Br-E murine leukemia virus.

    PubMed Central

    Gravel, C; Kay, D G; Jolicoeur, P

    1993-01-01

    The Cas-Br-E murine leukemia virus (MuLV) induces a progressive hindlimb paralysis accompanied by a spongiform myeloencephalopathy in susceptible mice. In order to better understand the pathological process leading to these neurodegenerative lesions, we have investigated the nature of the cell type(s) infected by the virus during the course of the disease in CFW/D and SWR/J mice. For this purpose, we used in situ hybridization with virus-specific probes in combination with cell-type-specific histochemical (lectin) and immunological markers as well as morphological assessment. In the early stage of infection, endothelial cells represented the main cell type expressing viral RNA in the central nervous system (CNS). With disease progression and the appearance of lesions, microglial cells became the major cell type infected, accounting for up to 65% of the total infected cell population in diseased areas. Morphologically, these cells appeared activated and were frequently found in clusters. Infection and activation of microglial cells were almost exclusively restricted to diseased regions of the CNS. Neurons in diseased regions were not discernibly infected with virus at either early or late times of disease progression. Similarly, the proportion of infected astrocytes was typically < 1%. Although some endothelial cells and oligodendrocytes were infected by the virus, their infection was not limited to diseased CNS regions. These results are consistent with a model of indirect motor neuron degeneration, subsequent to the infection of nonneuronal CNS cells and especially of microglial cells. Infected microglial cells may play a role in the disease process by releasing not only virions or viral env-gene-encoded gp70 proteins but also other factors which may be directly or indirectly toxic to neurons. Parallels between microglial cell infection by MuLV and by lentiviruses, and specifically by human immunodeficiency virus, are discussed. Images PMID:8411367

  20. Novel cytotoxic exhibition mode of antimicrobial peptide anoplin in MEL cells, the cell line of murine Friend leukemia virus-induced leukemic cells.

    PubMed

    Zhu, Li-Na; Fu, Cai-Yun; Zhang, Shi-Fu; Chen, Wei; Jin, Yuan-Ting; Zhao, Fu-Kun

    2013-09-01

    Anoplin is a recently discovered antimicrobial peptide (AMP) isolated from the venom sac of the spider wasp Anoplius samariensis, and it is one of the shortest α-helical AMP found naturally to date consisting of only ten amino acids. Previous results showed that anoplin exhibits potent antimicrobial activity but little hemolytic activity. In this study, we synthesized anoplin, studied its cytotoxicity in Friend virus-induced leukemia cells [murine erythroleukemia (MEL) cells], and proposed its possible mechanism. Our results showed that anoplin could inhibit the proliferation of MEL cells in a dose-dependent and time-dependent manner via disrupting the integrity of cell membrane, which indicated that anoplin exerts its cytotoxicity efficacy. In addition, the cell cycle distribution of MEL cells was arrested in the G₀/G₁ phase significantly. However, anoplin could not induce obvious apoptosis in MEL cells, as well as anoplin could not induce visible changes on morphology and quantity in the bone marrow cells isolated from normal mice. All of these results indicate that anoplin, as generally believed, is a selective AMP, a value characteristic in the design of safe therapeutic agents. The cytotoxicity of anoplin on MEL cells was mainly attributable to the plasma membrane perturbation and also to the intracellular events such as the arrest of cell cycle. Although this is an initial study that explored the activity of anoplin in vitro rather than in vivo, with the increasing resistance of conventional chemotherapy, there is no doubt that anoplin has desirable feature to be developed as a novel and selective anticancer agent. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

  1. Endogenous CD317/Tetherin limits replication of HIV-1 and murine leukemia virus in rodent cells and is resistant to antagonists from primate viruses.

    PubMed

    Goffinet, Christine; Schmidt, Sarah; Kern, Christian; Oberbremer, Lena; Keppler, Oliver T

    2010-11-01

    Human CD317 (BST-2/tetherin) is an intrinsic immunity factor that blocks the release of retroviruses, filoviruses, herpesviruses, and arenaviruses. It is unclear whether CD317 expressed endogenously in rodent cells has the capacity to interfere with the replication of the retroviral rodent pathogen murine leukemia virus (MLV) or, in the context of small-animal model development, contributes to the well-established late-phase restriction of human immunodeficiency virus type 1 (HIV-1). Here, we show that small interfering RNA (siRNA)-mediated knockdown of CD317 relieved a virion release restriction and markedly enhanced the egress of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) in rat cells, including primary macrophages. Moreover, rodent CD317 potently inhibited MLV release, and siRNA-mediated depletion of CD317 in a mouse T-cell line resulted in the accelerated spread of MLV. Several virus-encoded antagonists have recently been reported to overcome the restriction imposed by human or monkey CD317, including HIV-1 Vpu, envelope glycoproteins of HIV-2 and Ebola virus, Kaposi's sarcoma-associated herpesvirus K5, and SIV Nef. In contrast, both rat and mouse CD317 showed a high degree of resistance to these viral antagonists. These data suggest that CD317 is a broadly acting and conserved mediator of innate control of retroviral infection and pathogenesis that restricts the release of retroviruses and lentiviruses in rodents. The high degree of resistance of the rodent CD317 restriction factors to antagonists from primate viruses has implications for HIV-1 small-animal model development and may guide the design of novel antiviral interventions.

  2. Efficacy of JAK/STAT pathway inhibition in murine xenograft models of early T-cell precursor (ETP) acute lymphoblastic leukemia.

    PubMed

    Maude, Shannon L; Dolai, Sibasish; Delgado-Martin, Cristina; Vincent, Tiffaney; Robbins, Alissa; Selvanathan, Arthavan; Ryan, Theresa; Hall, Junior; Wood, Andrew C; Tasian, Sarah K; Hunger, Stephen P; Loh, Mignon L; Mullighan, Charles G; Wood, Brent L; Hermiston, Michelle L; Grupp, Stephan A; Lock, Richard B; Teachey, David T

    2015-03-12

    Early T-cell precursor (ETP) acute lymphoblastic leukemia (ALL) is a recently described subtype of T-ALL characterized by a unique immunophenotype and genomic profile, as well as a high rate of induction failure. Frequent mutations in cytokine receptor and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways led us to hypothesize that ETP-ALL is dependent on JAK/STAT signaling. Here we demonstrate aberrant activation of the JAK/STAT pathway in ETP-ALL blasts relative to non-ETP T-ALL. Moreover, ETP-ALL showed hyperactivation of STAT5 in response to interleukin-7, an effect that was abrogated by the JAK1/2 inhibitor ruxolitinib. In vivo, ruxolitinib displayed activity in 6 of 6 patient-derived murine xenograft models of ETP-ALL, with profound single-agent efficacy in 5 models. Ruxolitinib treatment decreased peripheral blast counts relative to pretreatment levels and compared with control (P < .01) in 5 of 6 ETP-ALL xenografts, with marked reduction in mean splenic blast counts (P < .01) in 6 of 6 samples. Surprisingly, both JAK/STAT pathway activation and ruxolitinib efficacy were independent of the presence of JAK/STAT pathway mutations, raising the possibility that the therapeutic potential of ruxolitinib in ETP-ALL extends beyond those cases with JAK mutations. These findings establish the preclinical in vivo efficacy of ruxolitinib in ETP-ALL, a biologically distinct subtype for which novel therapies are needed. © 2015 by The American Society of Hematology.

  3. Viral determinants that control the neuropathogenicity of PVC-211 murine leukemia virus in vivo determine brain capillary endothelial cell tropism of the virus in vitro.

    PubMed Central

    Masuda, M; Hoffman, P M; Ruscetti, S K

    1993-01-01

    PVC-211 murine leukemia virus (MuLV) is a neuropathogenic, weakly leukemogenic variant of the nonneuropathogenic, highly leukemogenic Friend MuLV (F-MuLV). Chimeric viruses constructed from PVC-211 MuLV clone 3d and F-MuLV clone 57 indicate that the env gene of PVC-211 MuLV contains the determinant(s) responsible for pathological changes in the central nervous system. However, sequences within the 5' one-third (AatII-EcoRI region) of the PVC-211 MuLV genome, which include the 5' leader sequence, the gag gene, and the 5' quarter of the pol gene, are also needed in conjunction with the env gene determinant(s) to cause clinically evident neurological disease in the majority of virus-infected animals after a short latency. In the presence of the AatII-EcoRI region of the PVC-211 MuLV genome, the PVC-211 MuLV env gene sequences encoding the amino-terminal half of the SU protein, which contains the receptor-binding region of the protein, were sufficient to cause rapidly progressive neurological disease. When PVC-211 MuLV, F-MuLV, and various chimeric viruses were tested for their ability to replicate in cultured brain capillary endothelial cells (BCEC), the primary site of PVC-211 MuLV replication within the central nervous system, there was a direct correlation between the replication efficiency of a virus in BCEC in vitro and its ability to cause neurological disease in vivo. This observation indicates that the sequences in PVC-211 MuLV that render it neuropathogenic affect its replication in BCEC and suggests that rapid and efficient replication of the virus in BCEC is crucial for the pathological changes in the central nervous system that result in development of neurological disease. Images PMID:8392599

  4. Immunopathology of B-cell lymphomas induced in C57BL/6 mice by dualtropic murine leukemia virus (MuLV).

    PubMed Central

    Pattengale, P. K.; Taylor, C. R.; Twomey, P.; Hill, S.; Jonasson, J.; Beardsley, T.; Haas, M.

    1982-01-01

    Combined clinicopathologic and immunomorphologic evidence is presented that would indicate that a murine leukemia virus (MuLV) with the dualtropic host range is capable of producing a clinically malignant lesion composed of immunoblasts and associated plasma cells in C57BL/6 mice. This process, morphologically diagnosed as an immunoblastic lymphoma of B cells using standard histopathologic criteria, was found to be distinctly polyclonal with regard to immunoglobulin (Ig) isotype when analyzed for both surface and cytoplasmic Ig. Further studies demonstrated that this clinicopathologically malignant, dualtropic MuLV-induced, polyclonal immunoblastic lymphoma of B cells in C57BL/6 mice was normal diploid and unable to be successfully transplanted to nonimmunosuppressed syngeneic recipients. Although all serum heavy and light chain components were found to be progressively elevated as the tumor load increased, the polyclonal increase in serum immunoglobulins was most pronounced for mu heavy and kappa light chains (ie, mu greater than gamma 2A greater than alpha greater than gamma 2B greater than gamma 1; kappa greater than lamba). The dissociation of clinicopathologic and biologic criteria for malignancy in the presently described dualtropic (RadLV) MuLV-induced B-cell lesion is sharply contrasted with the thymotropic (RadLV), MuLV-induced T-cell lymphoblastic lymphoma in C57BL/6 mice. This process is also a clinicopathologically malignant lesion but, when one uses biologic criteria, is found to be distinctly monoclonal, aneuploid, and easily transplanted to nonimmunosuppressed syngeneic recipients. The close clinicopathologic and biologic similarities of the dualtropic MuLV-induced animal model to corresponding human B-cell lymphoproliferative diseases are stressed. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 PMID:6282131

  5. Contributions to transcriptional activity and to viral leukemogenicity made by sequences within and downstream of the MCF13 murine leukemia virus enhancer.

    PubMed Central

    Tupper, J C; Chen, H; Hays, E F; Bristol, G C; Yoshimura, F K

    1992-01-01

    We have identified nucleotide sequences that regulate transcription in both a cell-type-specific and general manner in the long terminal repeat of the MCF13 murine leukemia virus. Besides the enhancer element, we have observed that the region between the enhancer and promoter (DEN) has a profound effect on transcription in different cell types. This effect, however, was dependent on the copy number of enhancer repeats and was detectable in the presence of a single repeat. When two enhancer repeats were present, the effect of DEN on transcription was abrogated except in T cells. DEN also makes a significant contribution to the leukemogenic property of the MCF13 retrovirus. Its deletion from the MCF13 virus dramatically reduced the incidence of thymic lymphoma and increased the latency of disease in comparison with the wild-type virus. This effect was most marked when one rather than two enhancer repeats was present in the mutant viruses. We also observed that the removal of one repeat alone remarkably reduced leukemogenicity by the MCF13 virus. A newly identified protein-binding site (MLPal) located within DEN affects transcription only in T cells, and its deletion attenuates the ability of an MCF13 virus with a single enhancer repeat to induce thymic lymphoma. This observation suggests that the MLPal protein-binding site contributes to the effect of the DEN region on T-cell-specific transcription and viral leukemogenicity. This study identifies the importance of nonenhancer sequences in the long terminal repeat for the oncogenesis of the MCF13 retrovirus. PMID:1331510

  6. Negative regulatory element associated with potentially functional promoter and enhancer elements in the long terminal repeats of endogenous murine leukemia virus-related proviral sequences

    SciTech Connect

    Ch'ang, L.Y.; Yang, W.K.; Myer, F.E.; Yang, D.M.

    1989-06-01

    Three series of recombinant DNA clones were constructed, with the bacterial chloramphenical acetyltransferase (CAT) gene as a quantitative indicator, to examine the activities of promoter and enhancer sequence elements in the 5' long terminal repeat (LTR) of murine leukemia virus (MuLV)-related proviral sequences isolated from the mouse genome. Transient CAT expression was determined in mouse NIH 3T3, human HT1080, and mink CCL64 cultured cells transfected with the LTR-CAT constructs. The 700-base pair (bp) LTRs of three polytropic MuLV-related proviral clones and the 750-bp LTRs of four modified polytropic proviral clones, in complete structures either with or without the adjacent downstream sequences, all showed very little or negligible activities for CAT expression, while ecotropic MuLV LTRs were highly active. The MuLV-related LTRs were divided into three portions and examined separately. The 3' portion of the MuLV-related LTRs that contains the CCAAC and TATAA boxes was found to be a functional promoter, being about one-half to one-third as active as the corresponding portion of the ecotropic MuLV LTRs. A MboI-Bg/II fragment, representing the distinct 190- to 200-pb inserted segment in the middle, was found to be a potential enhancer, especially when examined in combination with the simian virus 40 promoter in CCL64 cells. A PstI-MboI fragment of the 5' portion, which contains the protein-binding motifs on the enhancer segment as well as the upstream LTF sequences, showed moderate enhancer activities in CCL6 cells but was virtually inactive in NIH 3T3 cells and HT1080 cells; addition of this fragment to the ecotropic LTR-CAT constructs depressed CAT expression.

  7. Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins.

    PubMed

    Ahi, Yadvinder S; Zhang, Shu; Thappeta, Yashna; Denman, Audrey; Feizpour, Amin; Gummuluru, Suryaram; Reinhard, Bjoern; Muriaux, Delphine; Fivash, Matthew J; Rein, Alan

    2016-11-22

    Gammaretroviruses, such as murine leukemia viruses (MLVs), encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called "glycogag" (glycosylated Gag). MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes.

  8. Absence of evidence of Xenotropic Murine Leukemia Virus-related virus infection in persons with Chronic Fatigue Syndrome and healthy controls in the United States

    PubMed Central

    2010-01-01

    Background XMRV, a xenotropic murine leukemia virus (MuLV)-related virus, was recently identified by PCR testing in 67% of persons with chronic fatigue syndrome (CFS) and in 3.7% of healthy persons from the United States. To investigate the association of XMRV with CFS we tested blood specimens from 51 persons with CFS and 56 healthy persons from the US for evidence of XMRV infection by using serologic and molecular assays. Blinded PCR and serologic testing were performed at the US Centers for Disease Control and Prevention (CDC) and at two additional laboratories. Results Archived blood specimens were tested from persons with CFS defined by the 1994 international research case definition and matched healthy controls from Wichita, Kansas and metropolitan, urban, and rural Georgia populations. Serologic testing at CDC utilized a Western blot (WB) assay that showed excellent sensitivity to MuLV and XMRV polyclonal or monoclonal antibodies, and no reactivity on sera from 121 US blood donors or 26 HTLV-and HIV-infected sera. Plasma from 51 CFS cases and plasma from 53 controls were all WB negative. Additional blinded screening of the 51 cases and 53 controls at the Robert Koch Institute using an ELISA employing recombinant Gag and Env XMRV proteins identified weak seroreactivity in one CFS case and a healthy control, which was not confirmed by immunofluorescence. PCR testing at CDC employed a gag and a pol nested PCR assay with a detection threshold of 10 copies in 1 ug of human DNA. DNA specimens from 50 CFS patients and 56 controls and 41 US blood donors were all PCR-negative. Blinded testing by a second nested gag PCR assay at the Blood Systems Research Institute was also negative for DNA specimens from the 50 CFS cases and 56 controls. Conclusions We did not find any evidence of infection with XMRV in our U.S. study population of CFS patients or healthy controls by using multiple molecular and serologic assays. These data do not support an association of XMRV with

  9. Antitumor protection from the murine T-cell leukemia/lymphoma EL4 by the continuous subcutaneous coadministration of recombinant macrophage-colony stimulating factor and interleukin-2.

    PubMed

    Vallera, D A; Taylor, P A; Aukerman, S L; Blazar, B R

    1993-09-15

    Combined continuous s.c. coadministration of macrophage-colony stimulating factor (M-CSF) plus interleukin-2 (IL-2) by osmotic pump protected mice given i.v. injections of a lethal dose of EL4 T-cell leukemia/lymphoma. Antitumor protection was significantly greater than that afforded by treatment with either cytokine alone. Since neither IL-2 receptors nor M-CSF receptors were expressed on EL4, the antitumor effect was likely attributed to murine effector cells. To determine how M-CSF+IL-2 provided this effect, we performed immunophenotypic and functional analyses as well as in vivo depletion studies of putative antitumor effector cells. Splenic phenotyping experiments revealed that the highest levels of macrophages and natural killer cells were observed in mice given the cytokine combination rather than either M-CSF or IL-2 alone. In vivo depletion of natural killer cells ablated the antitumor protective effect of M-CSF and IL-2. T-cells were also important for M-CSF+IL-2 efficacy, since adult thymectomy/T-cell depletion significantly inhibited the ability of cytokine coadministration to protect against EL4. Coadministration of the 2 cytokines significantly elevated in vivo levels of CD3+CD4+, CD3+CD8+, CD3+NK1.1+ T-cells, and CD3+CD25+ (activated) T-cells, and elevated anti-EL4 cytotoxic T-cell activity measured in vitro. Although WBC counts and fluorescence-activated cell sorter studies showed that M-CSF+IL-2 treatment significantly elevated neutrophils, s.c. delivery of granulocyte-colony stimulating factor at doses sufficient to induce neutrophilia was unable to confer anti-EL4 protection. These studies indicate that macrophages, T-cells, and natural killer cells are all important in the M-CSF+IL-2 anti-EL4 response. The superior antitumor effect of this cytokine combination along with the ability of M-CSF to diminish the toxicity of IL-2 in this model suggests that further investigations into the clinical potential of this combination treatment are warranted.

  10. Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes

    PubMed Central

    1988-01-01

    T cells primed specifically for the envelope glycoprotein of Friend murine leukemia helper virus (F-MuLV) were prepared by immunizing mice with a recombinant vaccinia virus that expressed the entire env gene of F-MuLV. Significant proliferative responses of F-MuLV envelope- specific, H-2a/b T cells were observed when the T cells were stimulated with antigen-pulsed peritoneal exudate cells (PEC) having the b allele at the K, A beta, A alpha, and E beta loci of the H-2. On the other hand, PEC having only the kappa allele at these loci did not induce the envelope-specific T cell proliferation, even when the PEC had the b allele at the E alpha, S, or D loci. F-MuLV envelope-specific proliferation of H-2a/b T cells under the stimulation of antigen- pulsed, H-2a/b PEC was specifically blocked with anti-I-Ab and anti-I- Ek mAbs but not with anti-Kb, anti-Kk, or anti-I-Ak mAbs. Moreover, (B10.MBR x A/WySn)F1 mice that have the b allele only at the K locus but not in I-A subregion were nonresponders to the envelope glycoprotein, and the bm12 mutation at the A beta locus completely abolished the T cell responsiveness to this antigen. These results indicate that proliferative T cells recognize a limited number of epitopes on F-MuLV envelope protein in the context of I-Ab, hybrid I- Ak/b, and/or hybrid I-Ek/b class II MHC molecules but fail to recognize the same envelope protein in the context of I-Ak or I-Ek molecules. This influence of the H-2I region on T cell recognition of the envelope glycoprotein appeared to control in vivo induction of protective immunity against Friend virus complex after immunization with the vaccinia-F-MuLV env vaccine. Thus, these results provide, for the first time, direct evidence for Ir gene-controlled responder/nonresponder phenotypes influencing the immune response to a pathogenic virus of mice. PMID:3141552

  11. Production and characterization of a bicistronic Moloney-based retroviral vector expressing human interleukin 2 and herpes simplex virus thymidine kinase for gene therapy of cancer.

    PubMed

    Pizzato, M; Franchin, E; Calvi, P; Boschetto, R; Colombo, M; Ferrini, S; Palù, G

    1998-07-01

    Gene-based therapeutic strategies for cancer mainly include augmentation of immunotherapeutic and chemotherapeutic approaches. In this study we report the design and functional assay of a novel bicistronic Moloney-based retroviral vector expressing human interleukin-2 (IL-2) and herpesvirus thymidine kinase (tk) through a cap-dependent translation and an internal ribosome entry site (IRES)-regulated translation, respectively. This construct has the potential for allowing combination of cytokine and suicide gene therapy, especially in areas such as the brain, composed of post-mitotic cells refractory to transduction by type C retroviral vectors. Accordingly, human glioma cells were used as targets for gene transfer after selecting a packaging cell clone that produced a reasonable titer of recombinant virus and expressed high levels of IL-2 and tk transcripts. Although transduction efficiency was reduced in glioma cells as compared with murine NIH 3T3 cells, transgene expression was effectively achieved. Transduced glioma cells were sensitive to ganciclovir and secreted around 1000 U/ml IL-2 in the culture supernatants. Simultaneous production of IL-2 and tk in vivo by genetically treated tumor cells would hopefully potentiate the effect of gangiclovir-induced metabolic suicide, possibly by boosting the immune response associated with tumor debulking or by amplifying the bystander response.

  12. Localization of the labile disulfide bond between SU and TM of the murine leukemia virus envelope protein complex to a highly conserved CWLC motif in SU that resembles the active-site sequence of thiol-disulfide exchange enzymes.

    PubMed Central

    Pinter, A; Kopelman, R; Li, Z; Kayman, S C; Sanders, D A

    1997-01-01

    Previous studies have indicated that the surface (SU) and transmembrane (TM) subunits of the envelope protein (Env) of murine leukemia viruses (MuLVs) are joined by a labile disulfide bond that can be stabilized by treatment of virions with thiol-specific reagents. In the present study this observation was extended to the Envs of additional classes of MuLV, and the cysteines of SU involved in this linkage were mapped by proteolytic fragmentation analyses to the CWLC sequence present at the beginning of the C-terminal domain of SU. This sequence is highly conserved across a broad range of distantly related retroviruses and resembles the CXXC motif present at the active site of thiol-disulfide exchange enzymes. A model is proposed in which rearrangements of the SU-TM intersubunit disulfide linkage, mediated by the CWLC sequence, play roles in the assembly and function of the Env complex. PMID:9311907

  13. Lack of in vivo cross-resistance with 4'-thio-ara-C against drug-resistant murine P388 and L1210 leukemias.

    PubMed

    Waud, William R; Gilbert, Karen S; Secrist, John A

    2011-08-01

    4'-Thio-β-D-arabinofuranosylcytosine (4'-thio-ara-C), which has shown a broad spectrum of antitumor activity against human tumor systems in mice and is undergoing clinical trials, was evaluated for cross-resistance to seven clinical agents in order to identify potentially useful guides for patient selection for further clinical trials of 4'-thio-ara-C and possible noncross-resistant drug combinations with 4'-thio-ara-C. A drug resistance profile for 4'-thio-ara-C, which was administered intraperitoneally daily for nine consecutive days, was obtained using seven drug-resistant P388 and L1210 leukemias that were implanted intraperitoneally in mice. Multidrug-resistant P388 leukemias (leukemias resistant to doxorubicin, etoposide, or paclitaxel) exhibited no cross-resistance to 4'-thio-ara-C. Leukemias resistant to camptothecin, cisplatin, and 5-fluorouracil were also not cross-resistant to 4'-thio-ara-C. Only the leukemia resistant to 1-β-D-arabinofuranosylcytosine was cross-resistant to 4'-thio-ara-C. The data suggest that (1) it may be important to exclude or to monitor with extra care patients who have previously been treated with 1-β-D-arabinofuranosylcytosine and (2) the lack of cross-resistance seen with 4'-thio-ara-C may contribute to therapeutic synergism when 4'-thio-ara-C is combined with other agents.

  14. Effective treatment of a murine model of adult T-cell leukemia using 211At-7G7/B6 and its combination with unmodified anti-Tac (daclizumab) directed toward CD25

    PubMed Central

    Zhang, Zhuo; Zhang, Meili; Garmestani, Kayhan; Talanov, Vladimir S.; Plascjak, Paul S.; Beck, Barbara; Goldman, Carolyn; Brechbiel, Martin W.; Waldmann, Thomas A.

    2006-01-01

    Adult T-cell leukemia (ATL) consists of an overabundance of T cells, which express CD25. Therapeutic efficacy of astatine-211 (211At)–labeled murine monoclonal antibody 7G7/B6 alone and in combination with daclizumab was evaluated in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice given injections of MET-1 human T-cell leukemia cells. Daclizumab and 7G7/B6 are directed toward different epitopes of CD25. Either a single dose of 12 μCi (0.444 MBq) 211At-7G7/B6 per mouse given intravenously or receptor-saturating doses of daclizumab given at 100 μg weekly for 4 weeks intravenously inhibited tumor growth as monitored by serum levels of human β-2 microglobulin (β2μ) and by prolonged survival of leukemia-bearing mice compared with the control groups (P < .001). The combination of 2 agents enhanced the antitumor effect when compared with groups treated with 12 μCi (0.444 MBq) of 211At-7G7/B6 (P < .05) or daclizumab alone (P < .05). The median survival duration of the PBS group was 62.6 days and 61.5 days in the radiolabeled nonspecific antibody 211At-11F11–treated group. In contrast, 91% of mice in the combination group survived through day 94. These results that demonstrate a significantly improved therapeutic efficacy by combining 211At-7G7/B6 with daclizumab support a clinical trial of this regimen in patients with ATL. PMID:16569769

  15. A Comparison of the Anti-Tumor Effects of a Chimeric versus Murine Anti-CD19 Immunotoxins on Human B Cell Lymphoma and Pre-B Acute Lymphoblastic Leukemia Cell Lines

    PubMed Central

    Tsai, Lydia K.; Pop, Laurentiu M.; Liu, Xiaoyun; Vitetta, Ellen S.

    2011-01-01

    Precursor B cell acute lymphoblastic leukemia (pre-B ALL) affects five to six thousand adults and almost three thousand children every year. Approximately 25% of the children and 60% of the adults die from their disease, highlighting the need for new therapies that complement rather than overlap chemotherapy and bone marrow transplantation. Immunotherapy is a class of therapies where toxicities and mechanisms of action do not overlap with those of chemotherapy. Because CD19 is a B cell- restricted membrane antigen that is expressed on the majority of pre-B tumor cells, a CD19-based immunotherapy is being developed for ALL. In this study, the anti-tumor activities of immunotoxins (ITs) constructed by conjugating a murine monoclonal antibody (MAb), HD37, or its chimeric (c) construct to recombinant ricin toxin A chain (rRTA) were compared both in vitro using human pre-B ALL and Burkitt’s lymphoma cell lines and in vivo using a disseminated human pre-B ALL tumor cell xenograft model. The murine and chimeric HD37 IT constructs were equally cytotoxic to pre-B ALL and Burkitt’s lymphoma cells in vitro and their use in vivo resulted in equivalent increases in survival of SCID mice with human pre-B ALL tumors when compared with control mice. PMID:22069716

  16. Leukemia - B-Cell Prolymphocytic Leukemia and Hairy Cell Leukemia

    MedlinePlus

    ... and Hairy Cell Leukemia: Introduction Request Permissions Leukemia - B-cell Prolymphocytic Leukemia and Hairy Cell Leukemia: Introduction ... t k e P Types of Cancer Leukemia - B-cell Prolymphocytic Leukemia and Hairy Cell Leukemia Guide ...

  17. Rictor/mammalian target of rapamycin 2 regulates the development of Notch1 induced murine T-cell acute lymphoblastic leukemia via forkhead box O3.

    PubMed

    Hua, Chunlan; Guo, Huidong; Bu, Jiachen; Zhou, Mi; Cheng, Hui; He, Fuhong; Wang, Jinhong; Wang, Xiaomin; Zhang, Yinchi; Wang, Qianfei; Zhou, Jianfeng; Cheng, Tao; Xu, Mingjiang; Yuan, Weiping

    2014-12-01

    Mammalian target of rapamycin (mTOR) is composed of two distinct biochemical complexes, mTORC1 and mTORC2. In response to nutrients and growth factors, mTORC1 is known to control cellular growth by regulating the translational regulators S6 kinase 1 and 4E binding protein 1, whereas mTORC2 mediates cell proliferation and survival by activating Akt through phosphorylation at Ser473. Studies have shown that the deregulation of mTORC2 leads to the development of myeloproliferative disorder and leukemia in the phosphatase and tensin homolog deleted on chromosome ten (PTEN)-deleted mouse model. However, the mechanism by which mTORC2 specifically affects leukemogenesis is still not fully understood. Here, we investigated the role of mTORC2 in NOTCH1-driven T-cell acute lymphoblastic leukemia (T-ALL) in a Rictor-deficient mouse model. We found that, by deleting Rictor, an essential component of mTORC2, leukemia progression was significantly suppressed by arresting a greater proportion of Rictor(△/△) leukemic cells at the G0 phase of the cell cycle. Furthermore, the absence of Rictor led to the overexpression of chemotaxis-related genes, such as CCR2, CCR4 and CXCR4, which contributed to the homing and migration of Rictor-deficient T-ALL cells to the spleen but not the bone marrow. In addition, we demonstrated that inactivation of mTORC2 caused the overexpression of forkhead box O3 and its downstream effectors and eased the progression of leukemia in T-ALL mice. Our study thus indicates that forkhead box O3 could be a potential drug target for the treatment of T-ALL leukemia.

  18. Regulation of RNA splicing in gag-deficient mutants of Moloney murine sarcoma virus MuSVts110.

    PubMed Central

    De Mars, M; Sterner, D A; Chiocca, S M; Biggart, N W; Murphy, E C

    1990-01-01

    We investigated whether the MuSVts110 gag gene product (P58gag) can regulate the novel growth temperature dependence of MuSVts110 RNA splicing. MuSVts110 mutants with either frameshifts or deletions in the gag gene were tested for their ability to maintain the MuSVts110 splicing phenotype. Only small decreases in splicing efficiency and no changes in the thermosensitivity of viral RNA splicing were observed in MuSVts110 gag gene frameshift mutants. Deletions within the gag gene, however, variably decreased MuSVts110 splicing efficiency but had no effect on its thermosensitivity. Another class of MuSVts110 splicing mutants generated by treatment of MuSVts110-infected cells with NiCl2 was also examined. In these "nickel revertants," P58gag is made, but splicing of the viral transcript is nearly complete at all growth temperatures. The splicing of "tagged" viral RNA transcribed from a modified MuSVts110 DNA introduced into nickel revertant cells remained thermosensitive, arguing against trans effects of viral gene products on splicing efficiency. These experiments indicated that neither the MuSVts110 P58gag protein nor any other viral gene product acts in trans to regulate MuSVts110 splicing. Images PMID:2157036

  19. Effective therapy of murine models of human leukemia and lymphoma with radiolabeled anti-CD30 antibody, HeFi-1

    PubMed Central

    Zhang, Meili; Yao, Zhengsheng; Patel, Hiral; Garmestani, Kayhan; Zhang, Zhuo; Talanov, Vladimir S.; Plascjak, Paul S.; Goldman, Carolyn K.; Janik, John E.; Brechbiel, Martin W.; Waldmann, Thomas A.

    2007-01-01

    CD30 is a member of the TNF receptor superfamily. Overexpression of CD30 on some neoplasms versus limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise. In this study, we evaluated the therapeutic efficacy of an anti-CD30 antibody, HeFi-1, armed with 211At in a leukemia (karpas299) model and with 90Y in a lymphoma (SUDHL-1) model. Furthermore, we investigated the combination therapy of 211At-HeFi-1 with unmodified HeFi-1 in the leukemia model. Treatment with unmodified HeFi-1 significantly prolonged the survival of the karpas299-bearing mice compared with the controls (P < 0.001). Treatment with 211At-HeFi-1 showed greater therapeutic efficacy than that with unmodified HeFi-1 as shown by survival of the mice (P < 0.001). Combining these two agents further improved the survival of the mice compared with the groups treated with either 211At-HeFi-1 (P < 0.05) or unmodified HeFi-1 (P < 0.001) alone. In the lymphoma model, the survival of the SUDHL-1-bearing mice was significantly prolonged by the treatment with 90Y-HeFi-1 compared with the controls (P < 0.001). In summary, radiolabeled HeFi-1 is very promising for the treatment of CD30-expressing leukemias and lymphomas, and the combination regimen of 211At-HeFi-1 with unmodified HeFi-1 enhanced the therapeutic efficacy. PMID:17488826

  20. Effects of 28Si Ions, 56Fe Ions, and Protons on the Induction of Murine Acute Myeloid Leukemia and Hepatocellular Carcinoma

    PubMed Central

    Weil, Michael M.; Ray, F. Andrew; Genik, Paula C.; Yu, Yongjia; McCarthy, Maureen; Fallgren, Christina M.; Ullrich, Robert L.

    2014-01-01

    Estimates of cancer risks posed to space-flight crews by exposure to high atomic number, high-energy (HZE) ions are subject to considerable uncertainty because epidemiological data do not exist for human populations exposed to similar radiation qualities. We assessed the carcinogenic effects of 300 MeV/n 28Si or 600 MeV/n 56Fe ions in a mouse model for radiation-induced acute myeloid leukemia and hepatocellular carcinoma. C3H/HeNCrl mice were irradiated with 0.1, 0.2, 0.4, or 1 Gy of 300 MeV/n 28Si ions, 600 MeV/n 56Fe ions or 1 or 2 Gy of protons simulating the 1972 solar particle event (1972SPE) at the NASA Space Radiation Laboratory. Additional mice were irradiated with 137Cs gamma rays at doses of 1, 2, or 3 Gy. All groups were followed until they were moribund or reached 800 days of age. We found that 28Si or 56Fe ions do not appear to be substantially more effective than gamma rays for the induction of acute myeloid leukemia. However, 28Si or 56Fe ion irradiated mice had a much higher incidence of hepatocellular carcinoma than gamma ray irradiated or proton irradiated mice. These data demonstrate a clear difference in the effects of these HZE ions on the induction of leukemia compared to solid tumors, suggesting potentially different mechanisms of tumorigenesis. Also seen in this study was an increase in metastatic hepatocellular carcinoma in the 28Si and 56Fe ion irradiated mice compared with those exposed to gamma rays or 1972SPE protons, a finding with important implications for setting radiation exposure limits for space-flight crew members. PMID:25126721

  1. Leukemia - resources

    MedlinePlus

    The following organizations provide information on the different types of leukemia : Cancer Care -- www.cancercare.org/diagnosis/leukemia National Cancer Institute -- www.cancer.gov/types/leukemia The ...

  2. Alpha-phellandrene, a natural active monoterpene, influences a murine WEHI-3 leukemia model in vivo by enhancing macrophague phagocytosis and natural killer cell activity.

    PubMed

    Lin, Jen-Jyh; Lu, Kung-Wen; Ma, Yi-Shih; Tang, Nou-Ying; Wu, Ping-Ping; Wu, Chih-Chung; Lu, Hsu-Feng; Lin, Jaung-Geng; Chung, Jing-Gung

    2014-01-01

    α-phellandrene (α-PA), a cyclic monoterpene, is a natural compound reported to promote immune responses in normal BALB/c mice. The effects of α-PA on immune responses in a leukemia mouse model were examined. Mice were injected with mouse leukemia WEHI-3 cells and subsequently treated orally with or without α-PA (0, 25 and 50 mg/kg) and olive oil as positive control for two weeks. Leukocytes and splenocytes were isolated and cell markers for CD3, CD19, CD11b and Mac-3, phagocytosis and natural killer cell cytoxicity effects were analyzed by flow cytometry. α-PA increased the percentage of CD3 (T-cell marker), CD19 (B-cell marker) and MAC3 (macrophages) markers but reduced the percentage of CD11b (monocytes) cell surface markers. α-PA (25 and 50 mg/kg) increased phagocytosis of macrophages from blood samples and treatment promoted natural killer cell activity at 25 mg/kg from splenocytes. α-PA at 25 mg/kg also increased B- and T-cell proliferation.

  3. Identification and characterization of the specific murine NK cell subset supporting graft-versus-leukemia- and reducing graft-versus-host-effects

    PubMed Central

    Meinhardt, Kathrin; Kroeger, Irena; Bauer, Ruth; Ganss, Franziska; Ovsiy, Ilja; Rothamer, Johanna; Büttner, Maike; Atreya, Imke; Waldner, Maximilian; Bittrich, Max; Lehmann, Christian HK; Rieger, Michael A; Beilhack, Andreas; Zeiser, Robert; Edinger, Matthias; Dudziak, Diana; Mackensen, Andreas; Rehli, Michael; Ullrich, Evelyn

    2015-01-01

    Clinical studies investigating the impact of natural killer (NK) cells in allogeneic hematopoietic stem cell transplantation settings have yielded promising results. However, NK cells are a functionally and phenotypically heterogeneous population. Therefore, we addressed the functional relevance of specific NK cell subsets distinguished by expression of CD117, CD27 and CD11b surface markers in graft-versus-leukemia (GVL)-reaction and graft-versus-host-disease (GVHD). Our results clearly demonstrate that the subset of c-Kit−CD27−CD11b+ NK cells expressed multiple cytotoxic pathway genes and provided optimal graft-versus-leukemia-effects, while significantly reducing T cell proliferation induced by allogeneic dendritic cells. Furthermore, these NK cells migrated to inflamed intestinal tissues where graft-versus-host-colitis was efficiently mitigated. For the first time, we identified the c-Kit−CD27−CD11b+ NK cell population as the specific effector NK cell subset capable of significantly diminishing GVHD in fully mismatched bone marrow transplantation settings. In conclusion, the subset of c-Kit−CD27−CD11b+ NK cells not only supports GVL, but also plays a unique role in the protection against GVHD by migrating to the peripheral GVHD target organs where they exert efficient immunoregulatory activities. These new insights demonstrate the importance of selecting the optimal NK cell subset for cellular immunotherapy following allogeneic hematopoietic stem cell transplantation. PMID:25949862

  4. Identification and characterization of the specific murine NK cell subset supporting graft-versus-leukemia- and reducing graft-versus-host-effects.

    PubMed

    Meinhardt, Kathrin; Kroeger, Irena; Bauer, Ruth; Ganss, Franziska; Ovsiy, Ilja; Rothamer, Johanna; Büttner, Maike; Atreya, Imke; Waldner, Maximilian; Bittrich, Max; Lehmann, Christian Hk; Rieger, Michael A; Beilhack, Andreas; Zeiser, Robert; Edinger, Matthias; Dudziak, Diana; Mackensen, Andreas; Rehli, Michael; Ullrich, Evelyn

    2015-01-01

    Clinical studies investigating the impact of natural killer (NK) cells in allogeneic hematopoietic stem cell transplantation settings have yielded promising results. However, NK cells are a functionally and phenotypically heterogeneous population. Therefore, we addressed the functional relevance of specific NK cell subsets distinguished by expression of CD117, CD27 and CD11b surface markers in graft-versus-leukemia (GVL)-reaction and graft-versus-host-disease (GVHD). Our results clearly demonstrate that the subset of c-Kit(-)CD27(-)CD11b(+) NK cells expressed multiple cytotoxic pathway genes and provided optimal graft-versus-leukemia-effects, while significantly reducing T cell proliferation induced by allogeneic dendritic cells. Furthermore, these NK cells migrated to inflamed intestinal tissues where graft-versus-host-colitis was efficiently mitigated. For the first time, we identified the c-Kit(-)CD27(-)CD11b(+) NK cell population as the specific effector NK cell subset capable of significantly diminishing GVHD in fully mismatched bone marrow transplantation settings. In conclusion, the subset of c-Kit(-)CD27(-)CD11b(+) NK cells not only supports GVL, but also plays a unique role in the protection against GVHD by migrating to the peripheral GVHD target organs where they exert efficient immunoregulatory activities. These new insights demonstrate the importance of selecting the optimal NK cell subset for cellular immunotherapy following allogeneic hematopoietic stem cell transplantation.

  5. Activation of Membrane Fusion by Murine Leukemia Viruses Is Controlled in cis or in trans by Interactions between the Receptor-Binding Domain and a Conserved Disulfide Loop of the Carboxy Terminus of the Surface Glycoprotein

    PubMed Central

    Lavillette, Dimitri; Boson, Bertrand; Russell, Stephen J.; Cosset, François-Loïc

    2001-01-01

    Cell entry of retroviruses is initiated by the recognition of cellular receptors and the subsequent membrane fusion between viral and cellular membranes. These two steps are mediated by the surface (SU) and transmembrane (TM) subunits of the retroviral envelope glycoprotein (Env), respectively. Determinants regulating membrane fusion have been described throughout SU and TM, but the processes coupling receptor recognition to fusion are still elusive. Here we establish that a critical interaction is formed between the receptor-binding domain (RBD) and the major disulfide loop of the carboxy-terminal domain (C domain) of the murine leukemia virus SU. Receptor binding causes an alteration of this interaction and, in turn, promotes further events of Env fusion activation. We characterize mutations which, by lowering this interaction and reducing the compatibility between the RBD and C domains of Env glycoprotein chimeras, affect both Env fusogenicity and sensitivity to receptor interference. Additionally, we demonstrate that suboptimal interactions in such mutant Env proteins can be compensated in trans by soluble RBDs in a manner that depends on their compatibility with the C domain. Our results therefore indicate that RBD/C domain interactions may occur in cis, via the proper RBD of the viral Env itself, or in trans, via a distinct RBD expressed by virion-free Env glycoproteins expressed endogenously by the infected cells or provided by neighboring Env trimers. PMID:11264358

  6. Nucleotide sequences of gag-pol regions that determine the Fv-1 host range property of BALB/c N-tropic and B-tropic murine leukemia viruses

    SciTech Connect

    Ou, C.Y.; Boone, L.R.; Koh, C.K.; Tennant, R.W.; Yang, W.K.

    1983-12-01

    Previously, in virto recombinant DNA studies demonstrated that genetic determinants of N-tropism and B-tropism, or Fv-1-related host range properties of murine leukemia viruses, were located in a BamHI-HindIII DNA segment derived from the 5' portion of the coloned viral genome. We sequenced this segment and its immediate 5' region from cloned DNA of two BALB/c mouse C-type viruses (WN1802N and WN1802B) and found base differences at 12 positions out of the otherwise identical 1390-base-pair sequences. Analysis of the most likely reading frame showed that 6 of the 12 base differences would result in four encoded amino acid changes, three of which occur at positions 109 (glutamine in WN1802N versus threonine in WN1802B), 110 (arginine in WN1802N versus glutamic acid in WN1802B), and 159 (glutamic acid in WN1802N versus glycine in WN1802B) of the p30 protein. The remaining one is located at position 36 (threonine in WN1802N versus isoleucine in WN1802B) of the viral polymerase protein. Significant conformational alteration of the p30 protein could be predicted from these amino acid changes.

  7. Emergence of foreign H-2-like cytotoxicity and transplantation targets on vaccinia and Moloney virus-infected Meth. A tumour cells.

    PubMed

    Matossian-Rogers, A; Garrido, F; Festenstein, H

    1977-01-01

    Using cytotoxic effector cells of different anti-H-2 specificities, new cell-mediated lympholysis targets, normally undetected on Meth. A tumour cells, were shown after passage with vaccinia or Moloney virus. The H-2d CML targets on Meth. A cells recognized by B10.BR anti-B10.D2 effector cells were presented only after simultaneous vaccinia virus passage, while passage with Moloney virus caused the emergence of H-2b targets. Small but significant killing of vaccinia virus-passaged Meth.A was also obtained by anti-H-2k effector cells. These results are discussed in relation to in vivo experiments: retardation of tumour growth was noted in mice which had received several injections of vaccinia or Moloney virus, showing that the new CML targets were probably acting as transplantation targets.

  8. Potent efficacy of combined PI3K/mTOR and JAK or ABL inhibition in murine xenograft models of Ph-like acute lymphoblastic leukemia.

    PubMed

    Tasian, Sarah K; Teachey, David T; Li, Yong; Shen, Feng; Harvey, Richard C; Chen, I-Ming; Ryan, Theresa; Vincent, Tiffaney L; Willman, Cheryl L; Perl, Alexander E; Hunger, Stephen P; Loh, Mignon L; Carroll, Martin; Grupp, Stephan A

    2017-01-12

    Philadelphia chromosome (Ph)-like B-cell acute lymphoblastic leukemia (Ph-like ALL) is associated with activated JAK/STAT, Abelson kinase (ABL), and/or phosphatidylinositol 3-kinase (PI3K) signaling and poor clinical outcomes. PI3K pathway signaling inhibitors have been minimally investigated in Ph-like ALL. We hypothesized that targeted inhibition of PI3Kα, PI3Kδ, PI3K/mTOR, or target of rapamycin complex 1/2 (TORC1/TORC2) would decrease leukemia proliferation and abrogate aberrant kinase signaling and that combined PI3K pathway and JAK inhibition or PI3K pathway and SRC/ABL inhibition would have superior efficacy compared to inhibitor monotherapy. We treated 10 childhood ALL patient-derived xenograft models harboring various Ph-like genomic alterations with 4 discrete PI3K pathway protein inhibitors and observed marked leukemia reduction and in vivo signaling inhibition in all models. Treatment with dual PI3K/mTOR inhibitor gedatolisib resulted in near eradication of ALL in cytokine receptor-like factor 2 (CRLF2)/JAK-mutant models with mean 92.2% (range, 86.0%-99.4%) reduction vs vehicle controls (P < .0001) and in prolonged animal survival. Gedatolisib also inhibited ALL proliferation in ABL/platelet-derived growth factor receptor (PDGFR)-mutant models with mean 66.9% (range, 42.0%-87.6%) reduction vs vehicle (P < .0001). Combined gedatolisib and ruxolitinib treatment of CRLF2/JAK-mutant models more effectively inhibited ALL proliferation than either inhibitor alone (P < .001) and further enhanced survival. Similarly, superior efficacy of combined gedatolisib and dasatinib was observed in ABL/PDGFR-mutant models (P < .001). Overall, PI3K/mTOR inhibition potently decreased ALL burden in vivo; antileukemia activity was further enhanced with combination inhibitor therapy. Clinical trials testing combinations of kinase inhibitors in Ph-like ALL patients are indicated. © 2017 by The American Society of Hematology.

  9. The FIP1L1-PDGFRA fusion gene cooperates with IL-5 to induce murine hypereosinophilic syndrome (HES)/chronic eosinophilic leukemia (CEL)-like disease.

    PubMed

    Yamada, Yoshiyuki; Rothenberg, Marc E; Lee, Andrew W; Akei, Hiroko Saito; Brandt, Eric B; Williams, David A; Cancelas, Jose A

    2006-05-15

    Dysregulated tyrosine kinase activity by the Fip1-like1 (FIP1L1)-platelet-derived growth factor receptor alpha (PDGFRA) (F/P) fusion gene has been identified as a cause of clonal hypereosinophilic syndrome (HES), called F/P-positive chronic eosinophilic leukemia (CEL) in humans. However, transplantation of F/P-transduced hematopoietic stem cells/progenitors (F/P(+) HSCs/Ps) into mice results in a chronic myelogenous leukemia-like disease, which does not resemble HES. Because a subgroup of patients with HES show T-cell-dependent interleukin-5 (IL-5) overexpression, we determined if expression of the F/P fusion gene in the presence of transgenic T-cell IL-5 overexpression in mice induces HES-like disease. Mice that received a transplant of CD2-IL-5-transgenic F/P(+) HSC/Ps (IL-5Tg-F/P) developed intense leukocytosis, strikingly high eosinophilia, and eosinophilic infiltration of nonhematopoietic as well as hematopoietic tissues, a phenotype resembling human HES. The disease phenotype was transferable to secondary transplant recipients of a high cell dose, suggesting involvement of a short-term repopulating stem cell or an early myeloid progenitor. Induction of significant eosinophilia was specific for F/P since expression of another fusion oncogene, p210-BCR/ABL, in the presence of IL-5 overexpression was characterized by a significantly lower eosinophilia than IL-5Tg-F/P recipients. These results suggest that F/P is not sufficient to induce a HES/CEL-like disease but requires a second event associated with IL-5 overexpression.

  10. Genetic control of immune responses to Moloney sarcomas in rats: role of non-RT-1 background genes.

    PubMed

    Jones, J M

    1983-08-15

    Bone marrow chimeras, athymic nude rats and a congeneic strain were utilized to verify and further examine non-RT-1 linked background genes that influence immune responses of BN and LEW rats to Moloney sarcomas. In transplants that did not involve RT-1 incompatibility, infusion of high-responder bone marrow into a lethally irradiated low-responder recipient, or low-responder bone marrow into a high-responder recipient, would restore a high antibody response to the gp70 antigen of MuLV. Such transplants did not restore a high response to the p30 antigen. Athymic nude rats did not exhibit a significant response to either p30 or gp70 while euthymic littermates exhibited a significant response to both antigens. Growth of Moloney sarcomas as well as antibody and cellular responses to antigens expressed by such tumors were measured in LEW-IN rats which carry the RT-1 of BN and the background of LEW. For each of these parameters, LEW-IN resembled LEW more closely than BN.

  11. α-Phellandrene alters expression of genes associated with DNA damage, cell cycle, and apoptosis in murine leukemia WEHI-3 cells.

    PubMed

    Lin, Jen-Jyh; Yu, Chien-Chih; Lu, Kung-Wen; Chang, Shu-Jen; Yu, Fu-Shun; Liao, Ching-Lung; Lin, Jaung-Geng; Chung, Jing-Gung

    2014-08-01

    α-phellandrene (α-PA) is a cyclic monoterpene, present in natural plants such as Schinus molle L. α-PA promotes immune responses in mice in vivo. However, there is no available information on whether α-PA affects gene expression in leukemia cells. The present study determined effects of α-PA on expression levels of genes associated with DNA damage, cell cycle and apoptotic cell death in mouse leukemia WEHI-3 cells. WEHI-3 cells were treated with 10 μM α-PA for 24 h, cells were harvested and total RNA was extracted, and gene expression was analyzed by cDNA microarray. Results indicated that α-PA up-regulated 10 genes 4-fold, 13 by over 3-fold and 175 by over 2-fold; 21 genes were down-regulated by over 4-fold, 26 genes by over 3-fold and expression of 204 genes was altered by at leas 2-fold compared with the untreated control cells. DNA damage-associated genes such as DNA damage-inducer transcript 4 and DNA fragmentation factor were up-regulated by 4-fold and over 2-fold, respectively; cell-cycle check point genes such as cyclin G2 and cyclin-dependent kinases inhibitor 2D and IA (p21) were up-regulated by over 3-fold and over 2-fold, respectively; apoptosis-associated genes such as BCL2/adenovirus EIB interacting protein 3, XIAP-associated factor 1, BCL2 modifying factor, caspase-8 and FADD-like apoptosis regulator were over 2-fold up-regulated. Furthermore, DNA damage-associated gene TATA box binding protein was over 4-fold down-regulated, and D19Ertd652c (DNA segment) over 2-fold down-regulated; cell cycle-associated gene cyclin E2 was over 2-fold down-regulated; apoptosis associated gene growth arrest-specific 5 was over 9-fold down-regulated, Gm5426 (ATP synthase) was over 3-fold down-regulated, and death box polypeptide 33 was over 2-fold down-regulated. Based on these observations, α-PA altered gene expression in WEHI-3 cells in vitro.

  12. Synergistic Activity of Deguelin and Fludarabine in Cells from Chronic Lymphocytic Leukemia Patients and in the New Zealand Black Murine Model

    PubMed Central

    Rebolleda, Nerea; Losada-Fernandez, Ignacio; Perez-Chacon, Gema; Castejon, Raquel; Rosado, Silvia; Morado, Marta; Vallejo-Cremades, Maria Teresa; Martinez, Andrea; Vargas-Nuñez, Juan A.

    2016-01-01

    B-cell chronic lymphocytic leukemia (CLL) remains an incurable disease, and despite the improvement achieved by therapeutic regimes developed over the last years still a subset of patients face a rather poor prognosis and will eventually relapse and become refractory to therapy. The natural rotenoid deguelin has been shown to induce apoptosis in several cancer cells and cell lines, including primary human CLL cells, and to act as a chemopreventive agent in animal models of induced carcinogenesis. In this work, we show that deguelin induces apoptosis in vitro in primary human CLL cells and in CLL-like cells from the New Zealand Black (NZB) mouse strain. In both of them, deguelin dowregulates AKT, NFκB and several downstream antiapoptotic proteins (XIAP, cIAP, BCL2, BCL-XL and survivin), activating the mitochondrial pathway of apoptosis. Moreover, deguelin inhibits stromal cell-mediated c-Myc upregulation and resistance to fludarabine, increasing fludarabine induced DNA damage. We further show that deguelin has activity in vivo against NZB CLL-like cells in an experimental model of CLL in young NZB mice transplanted with spleen cells from aged NZB mice with lymphoproliferation. Moreover, the combination of deguelin and fludarabine in this model prolonged the survival of transplanted mice at doses of both compounds that were ineffective when administered individually. These results suggest deguelin could have potential for the treatment of human CLL. PMID:27101369

  13. Importance of a specific amino acid pairing for murine MLL leukemias driven by MLLT1/3 or AFF1/4.

    PubMed

    Lokken, Alyson A; Achille, Nicholas J; Chang, Ming-Jin; Lin, Jeffrey J; Kuntimaddi, Aravinda; Leach, Benjamin I; Malik, Bhavna; Nesbit, Jacqueline B; Zhang, Shubin; Bushweller, John H; Zeleznik-Le, Nancy J; Hemenway, Charles S

    2014-11-01

    Acute leukemias caused by translocations of the MLL gene at chromosome 11 band q23 (11q23) are characterized by a unique gene expression profile. More recently, data from several laboratories indicate that the most commonly encountered MLL fusion proteins, MLLT1, MLLT3, and AFF1 are found within a molecular complex that facilitates the elongation phase of mRNA transcription. Mutational analyses suggest that interaction between the MLLT1/3 proteins and AFF family proteins are required for experimental transformation of hematopoietic progenitor cells (HPCs). Here, we define a specific pairing of two amino acids that creates a salt bridge between MLLT1/3 and AFF proteins that is critically important for MLL-mediated transformation of HPCs. Our findings, coupled with the newly defined structure of MLLT3 in complex with AFF1, should facilitate the development of small molecules that block this amino acid interaction and interfere with the activity of the most common MLL oncoproteins.

  14. Induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway delays the initiation but fails to eradicate established murine acute myeloid leukemia.

    PubMed

    Jaako, P; Ugale, A; Wahlestedt, M; Velasco-Hernandez, T; Cammenga, J; Lindström, M S; Bryder, D

    2017-01-01

    Mutations resulting in constitutive activation of signaling pathways that regulate ribosome biogenesis are among the most common genetic events in acute myeloid leukemia (AML). However, whether ribosome biogenesis presents as a therapeutic target to treat AML remains unexplored. Perturbations in ribosome biogenesis trigger the 5S ribonucleoprotein particle (RNP)-Mdm2-p53 ribosomal stress pathway, and induction of this pathway has been shown to have therapeutic efficacy in Myc-driven lymphoma. In the current study we address the physiological and therapeutic role of the 5S RNP-Mdm2-p53 pathway in AML. By utilizing mice that have defective ribosome biogenesis due to downregulation of ribosomal protein S19 (Rps19), we demonstrate that induction of the 5S RNP-Mdm2-p53 pathway significantly delays the initiation of AML. However, even a severe Rps19 deficiency that normally results in acute bone marrow failure has no consistent efficacy on already established disease. Finally, by using mice that harbor a mutation in the Mdm2 gene disrupting its binding to 5S RNP, we show that loss of the 5S RNP-Mdm2-p53 pathway is dispensable for development of AML. Our study suggests that induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway holds limited potential as a single-agent therapy in the treatment of AML.

  15. Gan-Lu-Yin Inhibits Proliferation and Migration of Murine WEHI-3 Leukemia Cells and Tumor Growth in BALB/C Allograft Tumor Model

    PubMed Central

    Liu, Fon-Chang; Pan, Chun-Hsu; Lai, Ming-Tsung; Chang, Shu-Jen; Chung, Jing-Gung; Wu, Chieh-Hsi

    2013-01-01

    The aim of this study was to explore the antitumor effect of Gan-Lu-Yin (GLY), a traditional Chinese herbal formula, on leukemia. Ethanolic extract of GLY was applied to evaluate its regulatory mechanisms in proliferation, migration, and differentiation of WEHI-3 leukemic cells as well as antitumor effect on BALB/c mice model. The results showed that GLY markedly reduced cell proliferation and migration with induced differentiation of WEHI-3 cells. The expression level of phosphorylated FAK, Akt, ERK1/2, and Rb was decreased p21 expression while level was increased in WEHI-3 treated with GLY. The results of cell cycle analysis revealed that GLY treatment could markedly induce G1 phase arrest and decrease cell population in S phase. Moreover, experimental results demonstrated that GLY decreased the protein expression and enzyme activity of MMP-2 and MMP-9. GLY treatment also reduced WEHI-3 leukemic infiltration in liver and spleen and tumor growth in animal model. Accordingly, GLY demonstrated an inhibitory effect on tumor growth with a regulatory mechanism partially through inhibiting FAK, Akt, and ERK expression in WEHI-3 cells. GLY may provide a promising antileukemic approach in the clinical application. PMID:23573143

  16. Chronic myelogenous leukemia (CML)

    MedlinePlus

    CML; Chronic myeloid leukemia; Chronic granulocytic leukemia; Leukemia - chronic granulocytic ... nuclear disaster. It takes many years to develop leukemia from radiation exposure. Most people treated for cancer ...

  17. Childhood Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. It is the most common type of childhood cancer. ... blood cells help your body fight infection. In leukemia, the bone marrow produces abnormal white blood cells. ...

  18. Relationship between SU Subdomains That Regulate the Receptor-Mediated Transition from the Native (Fusion-Inhibited) to the Fusion-Active Conformation of the Murine Leukemia Virus Glycoprotein

    PubMed Central

    Lavillette, Dimitri; Ruggieri, Alessia; Boson, Bertrand; Maurice, Marielle; Cosset, François-Loïc

    2002-01-01

    Envelope glycoproteins (Env) of retroviruses are trimers of SU (surface) and TM (transmembrane) heterodimers and are expressed on virions in fusion-competent forms that are likely to be metastable. Activation of the viral receptor-binding domain (RBD) via its interaction with a cell surface receptor is thought to initiate a cascade of events that lead to refolding of the Env glycoprotein into its stable fusion-active conformation. While the fusion-active conformation of the TM subunit has been described in detail for several retroviruses, little is known about the fusion-competent structure of the retroviral glycoproteins or the molecular events that mediate the transition between the two conformations. By characterizing Env chimeras between the ecotropic and amphotropic murine leukemia virus (MLV) SUs as well as a set of point mutants, we show that alterations of the conformation of the SU glycoprotein strongly elevate Env fusogenicity by disrupting the stability of the Env complex. Compensatory mutations that restored both Env stability and fusion control were also identified, allowing definition of interactions within the Env complex that maintain the stability of the native Env complex. We show that, in the receptor-unbound form, structural interactions between the N terminus of the viral RBD (NTR domain), the proline-rich region (PRR), and the distal part of the C-terminal domain of the SU subunit maintain a conformation of the glycoprotein that is fusion inhibitory. Additionally, we identified mutations that disrupt this fusion-inhibitory conformation and allow fusion activation in the absence of viral receptors, provided that receptor-activated RBD fragments are added in trans during infection. Other mutations were identified that allow fusion activation in the absence of receptors for both the viral glycoprotein and the trans-acting RBD. Finally, we found mutations of the SU that bypass in cis the requirement for the NTR domain in fusion activation. All

  19. Relationship between SU subdomains that regulate the receptor-mediated transition from the native (fusion-inhibited) to the fusion-active conformation of the murine leukemia virus glycoprotein.

    PubMed

    Lavillette, Dimitri; Ruggieri, Alessia; Boson, Bertrand; Maurice, Marielle; Cosset, François-Loïc

    2002-10-01

    Envelope glycoproteins (Env) of retroviruses are trimers of SU (surface) and TM (transmembrane) heterodimers and are expressed on virions in fusion-competent forms that are likely to be metastable. Activation of the viral receptor-binding domain (RBD) via its interaction with a cell surface receptor is thought to initiate a cascade of events that lead to refolding of the Env glycoprotein into its stable fusion-active conformation. While the fusion-active conformation of the TM subunit has been described in detail for several retroviruses, little is known about the fusion-competent structure of the retroviral glycoproteins or the molecular events that mediate the transition between the two conformations. By characterizing Env chimeras between the ecotropic and amphotropic murine leukemia virus (MLV) SUs as well as a set of point mutants, we show that alterations of the conformation of the SU glycoprotein strongly elevate Env fusogenicity by disrupting the stability of the Env complex. Compensatory mutations that restored both Env stability and fusion control were also identified, allowing definition of interactions within the Env complex that maintain the stability of the native Env complex. We show that, in the receptor-unbound form, structural interactions between the N terminus of the viral RBD (NTR domain), the proline-rich region (PRR), and the distal part of the C-terminal domain of the SU subunit maintain a conformation of the glycoprotein that is fusion inhibitory. Additionally, we identified mutations that disrupt this fusion-inhibitory conformation and allow fusion activation in the absence of viral receptors, provided that receptor-activated RBD fragments are added in trans during infection. Other mutations were identified that allow fusion activation in the absence of receptors for both the viral glycoprotein and the trans-acting RBD. Finally, we found mutations of the SU that bypass in cis the requirement for the NTR domain in fusion activation. All

  20. Clinical-Grade-Expanded Regulatory T Cells Prevent Graft-versus-Host Disease While Allowing a Powerful T Cell-Dependent Graft-versus-Leukemia Effect in Murine Models.

    PubMed

    Del Papa, Beatrice; Ruggeri, Loredana; Urbani, Elena; Baldoni, Stefano; Cecchini, Debora; Zei, Tiziana; Iacucci Ostini, Roberta; Crescenzi, Barbara; Carotti, Alessandra; Pierini, Antonio; Sportoletti, Paolo; Di Bartolomeo, Paolo; Falzetti, Franca; Mecucci, Cristina; Velardi, Andrea; Martelli, Massimo F; Di Ianni, Mauro

    2017-07-17

    We developed a good manufacturing practices-compatible expansion protocol to improve number and purity of regulatory T cells (Tregs) available for clinical trials. Six clinical-grade separation procedures were performed, followed by expansion with high-dose interleukin (IL)-2, anti-CD3/anti-CD28 TCR stimulation, and rapamycin for 19 days achieving a median of 8.5-fold (range, 6.25 to 13.7) expansion. FOXP3 expression was stably maintained over the culture period, while the percentage of CD127 was significantly reduced. The in vitro suppression assay showed a strong Mixed Lymphocytes Reaction inhibition. In vitro amplification did not induce any karyotypic modification. To evaluate the graft-versus-host disease (GVHD)/graft-versus-leukemia (GVL) bifunctional axis, expanded Tregs and conventional T cells (Tcons) were tested in NOD/SCID/IL2Rgnull mice injected with primary acute myeloid leukemia (AML) cells, AML cell line, acute lymphoid leukemia Philadelphia cell line, or Burkitt-like lymphoma cell line. All mice that received leukemia cells together with expanded Tregs and Tcons were rescued from leukemia and survived without GVHD, showing that Treg expansion procedure did not compromise GVHD control and the strong Tcon-mediated GVL activity. This report might represent the basis for treating high-risk leukemia and/or relapsed/refractory leukemia patients with high-dose Treg/Tcons. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  1. Murine Typhus

    PubMed Central

    Dzul-Rosado, Karla R; Zavala Velázquez, Jorge Ernesto; Zavala-Castro, Jorge

    2012-01-01

    Rickettsia typhi: is an intracellular bacteria who causes murine typhus. His importance is reflected in the high frequency founding specific antibodies against Rickettsia typhi in several worldwide seroepidemiological studies, the seroprevalence ranging between 3-36%. Natural reservoirs of R. typhi are rats (some species belonging the Rattus Genus) and fleas (Xenopsylla cheopis) are his vector. This infection is associated with overcrowding, pollution and poor hygiene. Typically presents fever, headache, rash on trunk and extremities, in some cases may occur organ-specific complications, affecting liver, kidney, lung or brain. Initially the disease is very similar to other diseases, is very common to confuse the murine typhus with Dengue fever, therefore, ignorance of the disease is a factor related to complications or non-specific treatments for the resolution of this infection. This paper presents the most relevant information to consider about the rickettsiosis caused by Rickettsia typhi. PMID:24893060

  2. Commonly dysregulated genes in murine APL cells

    PubMed Central

    Yuan, Wenlin; Payton, Jacqueline E.; Holt, Matthew S.; Link, Daniel C.; Watson, Mark A.; DiPersio, John F.; Ley, Timothy J.

    2007-01-01

    To identify genes that are commonly dysregulated in a murine model of acute promyelocytic leukemia (APL), we first defined gene expression patterns during normal murine myeloid development; serial gene expression profiling studies were performed with primary murine hematopoietic progenitors that were induced to undergo myeloid maturation in vitro with G-CSF. Many genes were reproducibly expressed in restricted developmental “windows,” suggesting a structured hierarchy of expression that is relevant for the induction of developmental fates and/or differentiated cell functions. We compared the normal myeloid developmental transcriptome with that of APL cells derived from mice expressing PML-RARα under control of the murine cathepsin G locus. While many promyelocyte-specific genes were highly expressed in all APL samples, 116 genes were reproducibly dysregulated in many independent APL samples, including Fos, Jun, Egr1, Tnf, and Vcam1. However, this set of commonly dysregulated genes was expressed normally in preleukemic, early myeloid cells from the same mouse model, suggesting that dysregulation occurs as a “downstream” event during disease progression. These studies suggest that the genetic events that lead to APL progression may converge on common pathways that are important for leukemia pathogenesis. PMID:17008535

  3. Leukemia Viruses Associated with Mouse Myeloma Cells*

    PubMed Central

    Watson, J.; Ralph, P.; Sarkar, S.; Cohn, Melvin

    1970-01-01

    Myeloma cells derived from BALB/c and C3H mice show evidence of infection by a murine leumemia virus. The immunoglobulin-producing myelomas secrete an RNA-containing virus with a density of 1.20 to 1.22 gm/cm3. RNA with a sedimentation coefficient of 74 S in 0.1 M sodium sodium chloride has been isolated from secreted virus particles and has a base composition similar to that found for other murine leukemia virus RNA. An intracellular virus particle has been partially purified and has a density of 1.29 to 1.32 gm/cm3. Both extracellular and intracellular virus particles contain the leukemia virus group-specific antigen. Images PMID:4317914

  4. Understanding Leukemia

    MedlinePlus

    ... a microscope. Bone marrow biopsy I A very small amount of bone filled with marrow cells is removed through a needle. The cells are then looked at under a microscope. Each main type of leukemia also has different subtypes . In other words, patients ...

  5. Childhood Cancer: Leukemia (For Parents)

    MedlinePlus

    ... acute. Acute childhood leukemias are also divided into acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) , depending on ... Bone Marrow Childhood Cancer Neutropenia Stem Cell Transplants Acute Lymphoblastic Leukemia (ALL) Chemotherapy Radiation Therapy Chronic Myelogenous Leukemia (CML) ...

  6. Chronic Myelogenous Leukemia

    MedlinePlus

    Chronic myelogenous leukemia Overview Chronic myelogenous leukemia (CML) is an uncommon type of cancer of the blood cells. The term "chronic" in chronic myelogenous leukemia indicates that this cancer ...

  7. Enhanced amplification of hepatitis C virus (HCV) cDNA by PCR: detection of HCV RNA in archival sera.

    PubMed Central

    Beardsley, A M; Gowans, E J; Burrell, C J; Marmion, B P

    1996-01-01

    A reverse transcription-PCR assay which successfully amplified hepatitis C virus RNA from poorly stored archival sera was optimized. Maximum sensitivity was achieved with Moloney murine leukemia virus RNase H- reverse transcriptase and by a single round of PCR amplification of a short (112-bp) fragment of the 5' untranslated region of the viral genome. PMID:8735126

  8. Leukemia revisited

    SciTech Connect

    Cronkite, E P

    1980-01-01

    Selected features of the historical development of our knowledge of leukemia are discussed. The use of different methodologies for study of the nature of leukemic cell proliferation are analyzed. The differences between older cell kinetic data using tritiated thymidine and autoradiography and the newer cell culture methods are more apparent than real. It is suggested that tritiated thymidine and extracorporeal irradiation of the blood may be useful for therapeutic agents that have not been given an adequate trial. Radiation leukemogenesis presents an opportunity for study of the nature of leukemogenesis that has not been exploited adequately.

  9. The leukemias: Epidemiologic aspects

    SciTech Connect

    Linet, M.S.

    1984-01-01

    Particularly geared to physicians and cancer researchers, this study of the epidemiology and etiology of leukemia analyzes the four major leukemia subtypes in terms of genetic and familial determinant factors and examines the incidence, distribution and frequency of reported leukemia clusters. Linet discusses the connection between other types of malignancies, their treatments, and the subsequent development of leukemia and evaluates the impact on leukemia onset of such environmental factors as radiation therapy, drugs, and occupational hazards.

  10. Decitabine in Treating Children With Relapsed or Refractory Acute Myeloid Leukemia or Acute Lymphoblastic Leukemia

    ClinicalTrials.gov

    2013-01-22

    Childhood Acute Myeloblastic Leukemia With Maturation (M2); Childhood Acute Promyelocytic Leukemia (M3); Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia

  11. Childhood Cancer: Leukemia (For Parents)

    MedlinePlus

    ... Habits for TV, Video Games, and the Internet Leukemia KidsHealth > For Parents > Leukemia Print A A A ... Causes Symptoms Diagnosis Treatment en español Leucemia About Leukemia The term leukemia refers to cancers of the ...

  12. What Is Chronic Lymphocytic Leukemia?

    MedlinePlus

    ... About Chronic Lymphocytic Leukemia What Is Chronic Lymphocytic Leukemia? Cancer starts when cells in the body begin ... the lymph nodes, liver, and spleen. What is leukemia? Leukemia is a cancer that starts in the ...

  13. What Is Chronic Myeloid Leukemia?

    MedlinePlus

    ... About Chronic Myeloid Leukemia What Is Chronic Myeloid Leukemia? Cancer starts when cells in the body begin ... is the same as for adults. What is leukemia? Leukemia is a cancer that starts in the ...

  14. Supportive Care for Chronic Lymphocytic Leukemia

    MedlinePlus

    ... Chronic Lymphocytic Leukemia Supportive Care for Chronic Lymphocytic Leukemia Supportive care for chronic lymphocytic leukemia (CLL) is ... Treating Hairy Cell Leukemia More In Chronic Lymphocytic Leukemia About Chronic Lymphocytic Leukemia Causes, Risk Factors, and ...

  15. Structure, distribution, and expression of an ancient murine endogenous retroviruslike DNA family.

    PubMed Central

    Obata, M M; Khan, A S

    1988-01-01

    An endogenous retroviruslike DNA, B-26, was cloned from a BALB/c mouse embryo gene library by using a generalized murine leukemia virus DNA probe. Southern blot hybridization and nucleotide sequence analyses indicated that B-26 DNA might be a novel member of the GLN DNA family (A. Itin and E. Keshet, J. Virol. 59:301-307, 1986) which contains murine leukemia virus-related pol and env sequences. Northern analysis indicated that B-26-related RNAs of 8.4 and 3.0 kilobases were transcribed in thymus, spleen, brain, and liver tissues of 6-week-old BALB/c mice. Images PMID:3172346

  16. Retrovirus transduction: Generation of infectious retroviruses expressing dominant and selectable genes is associated with in vivo recombination and deletion events

    SciTech Connect

    Joyner, A.L.; Bernstein, A.

    1983-12-01

    The authors describe the generation of infectious retroviruses containing foreign genes by an in vivo recombination-deletion mechanism. Cotransfection into mouse cells of chimeric plasmids carrying a murine retrovirus 5' long terminal repeat and either the thymidine kinase (tk) gene of herpes virus or the dominant selectable bacterial gene for neomycin resistance (neo), along with a clone of Moloney murine leukemia virus, results in the generation of infectious thymidine kinase or neomycine-resistant viruses. Expression of the selectable marker in these viruses can be regulated by the homologous transcriptional promoter of the gene, by the promoter contained within the Friend spleen focus-forming virus long terminal repeat, or by the simian virus 40 early region promoter. In all cases, the rescued viruses appeared to arise by recombination in vivo with Moloney murine leukemia virus sequences, resulting in the acquisition of the Moloney 3' long terminal repeat and variable amounts of the 3' adjacent Moloney genome. In two of the thymidine kinase constructs where tk was inserted 200 base pairs downstream from the long terminal repeat, the rescued viruses acquired a large part of the murine leukemia virus genome, including the region involved in packaging genomic RNA into virions. The generation of infectious neomycin-resistant virus is associated with deletions of simian virus 40 splicing and polyadenylation sequences. These results demonstrate that nonhomologous recombination and deletion events can take place in animal cells, resulting in the acquisition or removal of cis-acting sequences required for, or inhibitory to, retrovirus infectivity.

  17. Leukemia & Lymphoma Society

    MedlinePlus

    ... Light The Night Man & Woman of the Year Leukemia Cup Regatta Student Series Lifestyle Community Careers at ... Special Projects Beat AML Patients & caregivers Disease Information Leukemia Lymphoma Myeloma Myelodysplastic Syndromes Myeloproliferative Neoplasms Childhood Blood ...

  18. Acute Myeloid Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood ...

  19. Acute Lymphocytic Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood ...

  20. Chronic Myeloid Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. ...

  1. Chronic Lymphocytic Leukemia

    MedlinePlus

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. ...

  2. Acute Lymphocytic Leukemia

    MedlinePlus

    ... treatment of acute lymphoblastic leukemia in children. In: Hematology: Basic Principles and Practice. 6th ed. Philadelphia, Pa.: ... et al. Acute lymphoblastic leukemia in adults. In: Hematology: Basic Principles and Practice. 6th ed. Philadelphia, Pa.: ...

  3. Role of natural killer cells in the mechanism of the antitumor effect of interferon on Moloney sarcoma virus-transformed cells.

    PubMed

    Fresa, K L; Murasko, D M

    1986-01-01

    The growth of tumors induced by inoculation of cells transformed by Moloney sarcoma virus can be inhibited by in situ administration of interferon (IFN) beginning one day after tumor challenge and continuing for 2 or 3 additional days. Inhibition of tumor growth by IFN was associated with a marked augmentation of natural killer (NK) cell activity, both in the spleen and at the site of tumor challenge, by day 5 after tumor challenge. However, using optimal conditions for IFN treatment, depletion of NK cells by in vivo treatment with anti-asialo GM1 prior to tumor challenge had no significant effect on inhibition of tumor growth by IFN. When the tumor load was greater or when IFN treatment was shorter, treatment with anti-asialo-GM1 partially abrogated the inhibition of tumor growth by IFN. In vitro assays gave no evidence of IFN enhancement of specific T-cell or activated macrophage antitumor effect. These results suggest that under optimal treatment conditions, the mechanism of the antitumor effect of IFN was independent of augmentation of NK activity, but under suboptimal conditions NK cells play a role in the mechanism of the antitumor effect of IFN.

  4. Removal of either N-glycan site from the envelope receptor binding domain of Moloney and Friend but not AKV mouse ecotropic gammaretroviruses alters receptor usage

    SciTech Connect

    Knoper, Ryan C.; Ferrarone, John; Yan Yuhe; Lafont, Bernard A.P.; Kozak, Christine A.

    2009-09-01

    Three N-linked glycosylation sites were removed from the envelope glycoproteins of Friend, Moloney, and AKV mouse ecotropic gammaretroviruses: gs1 and gs2, in the receptor binding domain; and gs8, in a region implicated in post-binding cell fusion. Mutants were tested for their ability to infect rodent cells expressing 4 CAT-1 receptor variants. Three mutants (Mo-gs1, Mo-gs2, and Fr-gs1) infect NIH 3T3 and rat XC cells, but are severely restricted in Mus dunni cells and Lec8, a Chinese hamster cell line susceptible to ecotropic virus. This restriction is reproduced in ferret cells expressing M. dunni dCAT-1, but not in cells expressing NIH 3T3 mCAT-1. Virus binding assays, pseudotype assays, and the use of glycosylation inhibitors further suggest that restriction is primarily due to receptor polymorphism and, in M. dunni cells, to glycosylation of cellular proteins. Virus envelope glycan size or type does not affect infectivity. Thus, host range variation due to N-glycan deletion is receptor variant-specific, cell-specific, virus type-specific, and glycan site-specific.

  5. AMKL chimeric transcription factors are potent inducers of leukemia.

    PubMed

    Dang, J; Nance, S; Ma, J; Cheng, J; Walsh, M P; Vogel, P; Easton, J; Song, G; Rusch, M; Gedman, A L; Koss, C; Downing, J R; Gruber, T A

    2017-03-10

    Acute megakaryoblastic leukemia in patients without Down syndrome is a rare malignancy with a poor prognosis. RNA sequencing of fourteen pediatric cases previously identified novel fusion transcripts that are predicted to be pathological including CBFA2T3-GLIS2, GATA2-HOXA9, MN1-FLI and NIPBL-HOXB9. In contrast to CBFA2T3-GLIS2, which is insufficient to induce leukemia, we demonstrate that the introduction of GATA2-HOXA9, MN1-FLI1 or NIPBL-HOXB9 into murine bone marrow induces overt disease in syngeneic transplant models. With the exception of MN1, full penetrance was not achieved through the introduction of fusion partner genes alone, suggesting that the chimeric transcripts possess a unique gain-of-function phenotype. Leukemias were found to exhibit elements of the megakaryocyte erythroid progenitor gene expression program, as well as unique leukemia-specific signatures that contribute to transformation. Comprehensive genomic analyses of resultant murine tumors revealed few cooperating mutations confirming the strength of the fusion genes and their role as pathological drivers. These models are critical for both the understanding of the biology of disease as well as providing a tool for the identification of effective therapeutic agents in preclinical studies.Leukemia advance online publication, 10 March 2017; doi:10.1038/leu.2017.51.

  6. Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia

    PubMed Central

    Herhaus, Peter; Habringer, Stefan; Philipp-Abbrederis, Kathrin; Vag, Tibor; Gerngross, Carlos; Schottelius, Margret; Slotta-Huspenina, Julia; Steiger, Katja; Altmann, Torben; Weißer, Tanja; Steidle, Sabine; Schick, Markus; Jacobs, Laura; Slawska, Jolanta; Müller-Thomas, Catharina; Verbeek, Mareike; Subklewe, Marion; Peschel, Christian; Wester, Hans-Jürgen; Schwaiger, Markus; Götze, Katharina; Keller, Ulrich

    2016-01-01

    Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [68Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche. PMID:27175029

  7. Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia.

    PubMed

    Herhaus, Peter; Habringer, Stefan; Philipp-Abbrederis, Kathrin; Vag, Tibor; Gerngross, Carlos; Schottelius, Margret; Slotta-Huspenina, Julia; Steiger, Katja; Altmann, Torben; Weißer, Tanja; Steidle, Sabine; Schick, Markus; Jacobs, Laura; Slawska, Jolanta; Müller-Thomas, Catharina; Verbeek, Mareike; Subklewe, Marion; Peschel, Christian; Wester, Hans-Jürgen; Schwaiger, Markus; Götze, Katharina; Keller, Ulrich

    2016-08-01

    Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [(68)Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche.

  8. What You Need to Know about Leukemia

    MedlinePlus

    ... Publications Reports What You Need To Know About™ Leukemia This booklet is about leukemia. Leukemia is cancer of the blood and bone marrow ( ... This book covers: Basics about blood cells and leukemia Types of doctors who treat leukemia Treatments for ...

  9. Targeted Therapy for Acute Lymphocytic Leukemia

    MedlinePlus

    ... Adults Treating Acute Lymphocytic Leukemia Targeted Therapy for Acute Lymphocytic Leukemia In recent years, new drugs that target specific ... Typical Treatment of Acute Lymphocytic Leukemia More In Acute Lymphocytic Leukemia About Acute Lymphocytic Leukemia Causes, Risk Factors, and ...

  10. What Is Acute Lymphocytic Leukemia (ALL)?

    MedlinePlus

    ... Adults About Acute Lymphocytic Leukemia (ALL) What Is Acute Lymphocytic Leukemia? Cancer starts when cells in the body begin ... Acute Lymphocytic Leukemia Research and Treatment? More In Acute Lymphocytic Leukemia About Acute Lymphocytic Leukemia Causes, Risk Factors, and ...

  11. Flavopiridol, Cytarabine, and Mitoxantrone in Treating Patients With Acute Leukemia

    ClinicalTrials.gov

    2013-10-07

    Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia

  12. [Hairy cell leukemia].

    PubMed

    Dietrich, S; Andrulis, M; Zenz, T

    2015-04-01

    Hairy cell leukemia was initially described as a distinct entity in 1958. It is rare B-cell malignancy characterized by an indolent course. Advances in the treatment and understanding of the biology of hairy cell leukemia have made the disease exquisitely amenable to treatment. This review summarizes the present understanding of hairy cell leukemia with a particular focus on the development of novel and targeted approaches to treatment.

  13. Comparative analysis of radiation- and virus-induced leukemias in BALB/c mice

    SciTech Connect

    Newcomb, E.W.; Binari, R.; Fleissner, E.

    1985-01-15

    Endogenous murine leukemia virus (MuLV) proviral copies were analyzed in thymomas induced in normal BALB/c (Fv-1b) and in Fv-1n congenic mice by X-irradiation. Both strains of mice developed leukemia with similar kinetics, indicating that N-tropism of endogenous MuLV was not a rate-limiting factor in development of disease. Southern blot analysis, using a probe specific for ecotropic virus and for ecotropic-specific sequences retained in pathogenic, env-recombinant viruses, showed that the majority of radiation leukemias lacked newly acquired, clonally integrated, proviruses. This was in contrast to virus-induced leukemias, which routinely exhibited several new proviral integration sites. When an internal proviral DNA restriction fragment was monitored, some radiation leukemias showed evidence of nonclonal infection, accounting for more frequent isolation of infectious virus from such leukemias. Differences in expression of T-cell surface antigens were found in X-ray-induced and virus-induced leukemias. All radiation leukemias were TL positive, whereas virus-induced leukemias were primarily negative for TL. Some differences were also found in Lyt-1 and Lyt-2 expression. The data as a whole suggest that, in the majority of cases, radiation leukemogenesis is not initiated by a viral route--that is, the sort of viral mechanism for which exogenous infection by known pathogenic MuLV is the paradigm.

  14. MLL-ENL-mediated leukemia initiation at the interface of lymphoid commitment.

    PubMed

    Ugale, A; Säwén, P; Dudenhöffer-Pfeifer, M; Wahlestedt, M; Norddahl, G L; Bryder, D

    2017-06-01

    Translocations involving the mixed lineage leukemia-1 are recurrent events in acute leukemia and associate with lymphoid (ALL), myeloid (AML) or mixed lineage (MLL) subtypes. Despite an association with ALL in humans, murine MLL fusion models are persistently restricted to AML. We here explored this issue using an inducible mixed lineage leukemia-eleven nineteen leukemia (MLL-ENL) mouse model. Although multiple progenitor cell types with myeloid potential are potent AML leukemia-initiating cells, also the earliest lymphoid progenitors were capable of initiating AML. This ability to evoke a latent myeloid potential in the earliest lymphoid progenitors was lost upon further lymphoid commitment. At the same time, more downstream/committed lymphoid precursors also failed to initiate lymphoid leukemia. Co-expression of MLL-ENL with a constitutively active RAS allele, the most common co-mutation in MLL fusion leukemias, could influence on both disease latency and lineage assignment of developing leukemia in what appears to be a mutation-order-dependent manner. Finally, CEBPB-mediated transdifferentation of committed and otherwise leukemia-incompetent B-cell progenitors imbued these cells with leukemic competence for AML. Therefore, apart from providing detailed insight into the differential responsiveness of candidate target cells to a first-hit MLL fusion event, our data warrants caution to therapeutic approaches based on the concept of transdifferentiation.

  15. Flavopiridol in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, or Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2013-06-03

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Blastic Phase Chronic Myelogenous Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Relapsing Chronic Myelogenous Leukemia

  16. Nearest-neighbor interactions of the major RNA tumor virus glycoprotein on murine cell surfaces.

    PubMed Central

    Takemoto, L J; Fox, C F; Jensen, F C; Elder, J H; Lerner, R A

    1978-01-01

    Formaldehyde-fixed Staphylococcus aureus and monospecific antiserum to gp70, the major envelope glycoprotein of murine leukemia virus, were used to immunoadsorb gp70 from Nonidet P40 extracts prepared from surface-radioiodinated murine cells. The labeled gp70 molecules in these cells were linked to a protein of approximately 15,000 daltons via native disulfide bonding. Prior treatment of cells with the reversible, bifunctional, crosslinking reagent dimethyl-3,3'-dithiobispropionimidate, followed by immunoadsorption and two-dimensional diagonal electrophoresis, revealed apparent homodimers and homotrimers of the 85,000-dalton complex. Identical treatment of purified type C RNA tumor virus from murine cells also revealed homodimeric and homotrimeric species, demonstrating similar self-associating tendencies of this glycoprotein in both intact virus and the plasma membrane of nonproducing murine cells. One cross-linked product consistently detected on the surfaces of murine cells was not present after crosslinking of a representative strain of murine leukemia virus. Images PMID:211503

  17. The Family Leukemia Association

    ERIC Educational Resources Information Center

    Pollitt, Eleanor

    1976-01-01

    An association of families of children with leukemia, the Family Leukemia Association (FLA), was recently established in Toronto. This paper discusses (a) philosophy of the FLA; (b) formative years of this organization; (c) problems encountered by leukemic children and their families; and (d) the FLA's past and future educational and social…

  18. The Family Leukemia Association

    ERIC Educational Resources Information Center

    Pollitt, Eleanor

    1976-01-01

    An association of families of children with leukemia, the Family Leukemia Association (FLA), was recently established in Toronto. This paper discusses (a) philosophy of the FLA; (b) formative years of this organization; (c) problems encountered by leukemic children and their families; and (d) the FLA's past and future educational and social…

  19. [Acute plasma cell leukemia].

    PubMed

    Monsalbe, V; Domíngues, C; Roa, I; Busel, D; González, S

    1989-01-01

    Plasma Cell Leukemia is a very rare form of plasmocytic dyscrasia, whose clinical and pathological characteristics warrant its recognition as a distinct subentity. We report the case of a 60 years old man who presented a rapidly fatal acute plasma cell leukemia, with multiple osteolytic lesions, hipercalcemia, renal and cardiac failure.

  20. Fludarabine Phosphate and Total-Body Irradiation Before Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Leukemia

    ClinicalTrials.gov

    2016-07-18

    B-Cell Prolymphocytic Leukemia; Chronic Lymphocytic Leukemia; Prolymphocytic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; T-Cell Prolymphocytic Leukemia

  1. Leukemia Cutis Associated with Secondary Plasma Cell Leukemia.

    PubMed

    DeMartinis, Nicole C; Brown, Megan M; Hinds, Brian R; Cohen, Philip R

    2017-05-09

    Plasma cell leukemia is an uncommon, aggressive variant of leukemia that may occur de novo or in association with multiple myeloma. Leukemia cutis is the cutaneous manifestation of leukemia, and indicates an infiltration of the skin by malignant leukocytes or their precursors. Plasma cell leukemia cutis is a rare clinical presentation of leukemia. We present a man who developed plasma cell leukemia cutis in association with multiple myeloma. Cutaneous nodules developed on his arms and legs 50 days following an autologous stem cell transplant. Histopathologic examination showed CD138-positive nodular aggregates of atypical plasma cells with kappa light chain restriction, similar to the phenotype of his myeloma. In spite of systemic treatment of his underlying disease, he died 25 days after the presentation of leukemia cutis. Pub-Med was searched for the following terms: cutaneous plasmacytomas, leukemia cutis, plasma cell leukemia nodules, plasma cell leukemia cutis, and secondary cutaneous plasmacytoma. Papers were reviewed and appropriate references evaluated. Leukemia cutis in plasma cell leukemia patients is an infrequent occurrence. New skin lesions in patients with plasma cell leukemia should be biopsied for pathology and for tissue cultures to evaluate for cancer or infection, respectively. The diagnosis plasma cell leukemia cutis is associated with a very poor prognosis.

  2. Role of CXCR4-mediated bone marrow colonization in CNS infiltration by T cell acute lymphoblastic leukemia.

    PubMed

    Jost, Tanja Rezzonico; Borga, Chiara; Radaelli, Enrico; Romagnani, Andrea; Perruzza, Lisa; Omodho, Lorna; Cazzaniga, Giovanni; Biondi, Andrea; Indraccolo, Stefano; Thelen, Marcus; Te Kronnie, Geertruy; Grassi, Fabio

    2016-06-01

    Infiltration of the central nervous system is a severe trait of T cell acute lymphoblastic leukemia. Inhibition of CXC chemokine receptor 4 significantly ameliorates T cell acute lymphoblastic leukemia in murine models of the disease; however, signaling by CXC chemokine receptor 4 is important in limiting the divagation of peripheral blood mononuclear cells out of the perivascular space into the central nervous system parenchyma. Therefore, Inhibition of CXC chemokine receptor 4 potentially may untangle T cell acute lymphoblastic leukemia cells from retention outside the brain. Here, we show that leukemic lymphoblasts massively infiltrate cranial bone marrow, with diffusion to the meninges without invasion of the brain parenchyma, in mice that underwent xenotransplantation with human T cell acute lymphoblastic leukemia cells or that developed leukemia from transformed hematopoietic progenitors. We tested the hypothesis that T cell acute lymphoblastic leukemia neuropathology results from meningeal infiltration through CXC chemokine receptor 4-mediated bone marrow colonization. Inhibition of leukemia engraftment in the bone marrow by pharmacologic CXC chemokine receptor 4 antagonism significantly ameliorated neuropathologic aspects of the disease. Genetic deletion of CXCR4 in murine hematopoietic progenitors abrogated leukemogenesis induced by constitutively active Notch1, whereas lack of CCR6 and CCR7, which have been shown to be involved in T cell and leukemia extravasation into the central nervous system, respectively, did not influence T cell acute lymphoblastic leukemia development. We hypothesize that lymphoblastic meningeal infiltration as a result of bone marrow colonization is responsible for the degenerative alterations of the neuroparenchyma as well as the alteration of cerebrospinal fluid drainage in T cell acute lymphoblastic leukemia xenografts. Therefore, CXC chemokine receptor 4 may constitute a pharmacologic target for T cell acute lymphoblastic

  3. Leukemias in Children.

    PubMed

    Seth, Rachna; Singh, Amitabh

    2015-09-01

    Childhood cancers are rare but an important cause of morbidity and mortality in children younger than 15 y of age. Common childhood malignancies include leukemias (commonest, 30-40%), brain tumors (20%) and lymphoma (12%) followed by neuroblastoma, retinoblastoma and tumors arising from soft tissues, bones and gonads. Leukemias, the commonest childhood cancer, arise from clonal proliferation of abnormal hematopoietic cells leading to disruption of normal marrow function and marrow failure. The various clinical manifestations of leukemia result from unregulated proliferation of the malignant clone and bone marrow failure. There are two main subtypes, the commoner, acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). A small proportion may have chronic myeloid leukemia (CML) and juvenile myelomonocytic leukemia (JMML). A systematic approach is necessary for diagnosis. Treatment should be initiated as early as possible to avoid complications. A timely referral to a cancer center must be done if facilities for diagnosis/treatment, management of complications and provision for supportive care are not available at the treating center.

  4. Sorafenib in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, or Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2013-01-08

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia

  5. [Therapeutic effect of focal adhesion kinase gene silence on leukemia].

    PubMed

    Xu, Lü-Hong; Fang, Jian-Pei; Weng, Wen-Jun; Xu, Hong-Gui; Zhang, Ya-Ting

    2011-06-01

    This study was aimed to investigate the effects of focal adhesion kinase (FAK) gene silence on leukemia cell growth, leukemogenesis and efficacy of chemotherapy drug. Vector containing lentiviral-FAK-shRNA was constructed and transfected into BCR/ABL-BaF3 leukemic cells, the cell growth and apoptosis were detected in vitro. The effect of FAK shRNA on leukemogenesis was studied in a murine model with leukemia. The apoptosis of leukemia cells and survival of leukemic mice treated by FAK shRNA combined with drug STI571 were monitored. The results showed that FAK gene expression was knocked down by lentiviral-FAK-shRNA. FAK gene silencing inhibited leukemia cell growth in vitro. The apoptosis test results showed that the percentages of Annexin V(+) cells in vector control group and FAK shRNA group were (3.46 ± 0.56)% and (7.3 ± 0.79)%, respectively, and the difference was statistically significant (p < 0.05). The mice in vector control group died at day 21 to 27, while the mice in FAK shRNA group died between day 52 and 60, and the difference was statistically significant (p < 0.05). Moreover, FAK gene silence combined with drug STI571 could enhance the apoptosis of leukemia cells and prolong survival time of leukemic mice. It is concluded that FAK gene silence inhibits leukemogenesis and promotes efficacy of chemotherapy drug on leukemia cells, indicating FAK gene silence may be considered as a new therapeutic strategy for leukemia.

  6. Dermatoglyphics in childhood leukemia

    PubMed Central

    Berka, Ludmila; McClure, P. D.; Sonley, Marilyn J.; Thompson, Margaret W.

    1971-01-01

    The dermatoglyphics of 54 leukemic children do not differ significantly from those of 25 mothers and 592 unrelated controls with respect to frequency of digital pattern types, position of axial triradius, or type of palmar flexion creases. These findings do not support the hypothesis that children with leukemia have an increased frequency of unusual dermal patterns, but suggest that the dermatoglyphics of leukemic children are not distinctive and therefore have no practical value in the diagnosis of childhood leukemia. Whatever factors are responsible for the development of leukemia in children, these factors do not appear regularly to affect the differentiation of the dermal ridges. PMID:5112119

  7. Conventional murine gene targeting.

    PubMed

    Zimmermann, Albert G; Sun, Yue

    2013-01-01

    Murine gene knockout models engineered over the last two decades have continued to demonstrate their potential as invaluable tools in understanding the role of gene function in the context of normal human development and disease. The more recent elucidation of the human and mouse genomes through sequencing has opened up the capability to elucidate the function of every human gene. State-of-the-art mouse model generation allows, through a multitude of experimental steps requiring careful standardization, gene function to be reliably and predictably ablated in a live model system. The application of these standardized methodologies to directly target gene function through murine gene knockout has to date provided comprehensive and verifiable genetic models that have contributed tremendously to our understanding of the cellular and molecular pathways underlying normal and disease states in humans. The ensuing chapter provides an overview of the latest steps and procedures required to ablate gene function in a murine model.

  8. Acute Myeloid Leukemia (AML) (For Parents)

    MedlinePlus

    ... TV, Video Games, and the Internet Acute Myeloid Leukemia (AML) KidsHealth > For Parents > Acute Myeloid Leukemia (AML) ... Treatment Coping en español Leucemia mieloide aguda About Leukemia Leukemia is a type of cancer that affects ...

  9. Can Acute Myeloid Leukemia Be Prevented?

    MedlinePlus

    ... Causes, Risk Factors, and Prevention Can Acute Myeloid Leukemia Be Prevented? It’s not clear what causes most ... Myeloid Leukemia Be Prevented? More In Acute Myeloid Leukemia About Acute Myeloid Leukemia Causes, Risk Factors, and ...

  10. Drugs Approved for Leukemia

    Cancer.gov

    This page lists cancer drugs approved by the FDA for use in leukemia. The drug names link to NCI's Cancer Drug Information summaries. The list includes generic names, brand names, and common drug combinations, which are shown in capital letters.

  11. Clonal evolution in leukemia.

    PubMed

    Ferrando, Adolfo A; López-Otín, Carlos

    2017-10-06

    Human leukemias are liquid malignancies characterized by diffuse infiltration of the bone marrow by transformed hematopoietic progenitors. The accessibility of tumor cells obtained from peripheral blood or through bone marrow aspirates, together with recent advances in cancer genomics and single-cell molecular analysis, have facilitated the study of clonal populations and their genetic and epigenetic evolution over time with unprecedented detail. The results of these analyses challenge the classic view of leukemia as a clonal homogeneous diffuse tumor and introduce a more complex and dynamic scenario. In this review, we present current concepts on the role of clonal evolution in lymphoid and myeloid leukemia as a driver of tumor initiation, disease progression and relapse. We also discuss the implications of these concepts in our understanding of the evolutionary mechanisms involved in leukemia transformation and therapy resistance.

  12. CT findings in leukemia

    SciTech Connect

    Heiberg, E.; Wolverson, M.K.; Sundaram, M.; Shields, J.B.

    1984-12-01

    Review of 84 computed tomographic (CT) scans in leukemic patients demonstrate a wide spectrum of abnormalities. Findings caused by leukemia were lymphadenopathy, visceral enlargement, focal defects, and tissue infiltration. Hemorrhage was by far the most common complication and could usually be characterized on the noncontrast CT scan. The distinction between old hematomas, foci of infection, and leukemia infiltration could not be made with certainty without CT-guided aspiration. Unusual instances of sepsis, such as microabscesses of the liver and typhlitis, were seen.

  13. Treatment of Children with APL (Acute Promyelocytic Leukemia)

    MedlinePlus

    ... Childhood Leukemia Treatment of Children With Acute Promyelocytic Leukemia (APL) Treatment of acute promyelocytic leukemia (APL), the ... With Chronic Myelogenous Leukemia (CML) More In Childhood Leukemia About Childhood Leukemia Causes, Risk Factors, and Prevention ...

  14. Treatment of Chronic Lymphocytic Leukemia by Risk Group

    MedlinePlus

    ... Chronic Lymphocytic Leukemia Typical Treatment of Chronic Lymphocytic Leukemia Treatment options for chronic lymphocytic leukemia (CLL) vary ... Treating Hairy Cell Leukemia More In Chronic Lymphocytic Leukemia About Chronic Lymphocytic Leukemia Causes, Risk Factors, and ...

  15. Myeloid leukemia after hematotoxins

    SciTech Connect

    Larson, R.A.; LeBeau, M.M.; Vardiman, J.W.; Rowley, J.D.

    1996-12-01

    One of the most serious consequences of cancer therapy is the development of a second cancer, especially leukemia. Several distinct subsets of therapy-related leukemia can now be distinguished. Classic therapy-related myeloid leukemia typically occurs 5 to 7 years after exposure to alkylating agents and/or irradiation, has a myelodysplastic phase with trilineage involvement, and is characterized by abnormalities of the long arms of chromosomes 5 and/or 7. Response to treatment is poor, and allogeneic bone marrow transplantation is recommended. Leukemia following treatment with agents that inhibit topoisomerase 11, however, has a shorter latency, no preleukemic phase, a monoblastic, myelomonocytic, or myeloblastic phenotype, and balanced translocations, most commonly involving chromosome bands 11 q23 or 21 q22. The MLL gene at 11 q23 or the AML1 gene at 21 q22 are almost uniformly rearranged. MLL is involved with many fusion gene partners. Therapy-related acute lymphoblastic leukemia also occurs with 1 1 q23 rearrangements. Therapy-related leukemias with 11 q23 or 21 q22 rearrangements, inv(16) or t(15;17), have a more favorable response to treatment and a clinical course similar to their de novo counterparts. 32 refs., 4 tabs.

  16. Tipifarnib and Bortezomib in Treating Patients With Acute Leukemia or Chronic Myelogenous Leukemia in Blast Phase

    ClinicalTrials.gov

    2015-04-14

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With Minimal Differentiation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Blastic Phase; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Disease; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia

  17. AKT capture by feline leukemia virus.

    PubMed

    Kawamura, Maki; Umehara, Daigo; Odahara, Yuka; Miyake, Ariko; Ngo, Minh Ha; Ohsato, Yoshiharu; Hisasue, Masaharu; Nakaya, Masa-Aki; Watanabe, Shinya; Nishigaki, Kazuo

    2017-04-01

    Oncogene-containing retroviruses are generated by recombination events between viral and cellular sequences, a phenomenon called "oncogene capture". The captured cellular genes, referred to as "v-onc" genes, then acquire new oncogenic properties. We report a novel feline leukemia virus (FeLV), designated "FeLV-AKT", that has captured feline c-AKT1 in feline lymphoma. FeLV-AKT contains a gag-AKT fusion gene that encodes the myristoylated Gag matrix protein and the kinase domain of feline c-AKT1, but not its pleckstrin homology domain. Therefore, it differs structurally from the v-Akt gene of murine retrovirus AKT8. AKT may be involved in the mechanisms underlying malignant diseases in cats.

  18. BMS-214662 in Treating Patients With Acute Leukemia, Myelodysplastic Syndrome, or Chronic Myeloid Leukemia

    ClinicalTrials.gov

    2013-01-22

    Adult Acute Promyelocytic Leukemia (M3); Blastic Phase Chronic Myelogenous Leukemia; Childhood Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia

  19. Flavopiridol and Vorinostat in Treating Patients With Relapsed or Refractory Acute Leukemia or Chronic Myelogenous Leukemia or Refractory Anemia

    ClinicalTrials.gov

    2013-04-01

    Blastic Phase Chronic Myelogenous Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Relapsing Chronic Myelogenous Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Myeloid Leukemia

  20. Murine embryonic stem cells secrete cytokines/growth modulators that enhance cell survival/anti-apoptosis and stimulate colony formation of murine hematopoietic progenitor cells.

    PubMed

    Guo, Ying; Graham-Evans, Barbara; Broxmeyer, Hal E

    2006-04-01

    Stromal cell-derived factor (SDF)-1/CXCL12, released by murine embryonic stem (ES) cells, enhances survival, chemotaxis, and hematopoietic differentiation of murine ES cells. Conditioned medium (CM) from murine ES cells growing in the presence of leukemia inhibitory factor (LIF) was generated while the ES cells were in an undifferentiated Oct-4 expressing state. ES cell-CM enhanced survival of normal murine bone marrow myeloid progenitors (CFU-GM) subjected to delayed growth factor addition in vitro and decreased apoptosis of murine bone marrow c-kit(+)lin- cells. ES CM contained interleukin (IL)-1alpha, IL-10, IL-11, macrophage-colony stimulating factor (CSF), oncostatin M, stem cell factor, vascular endothelial growth factor, as well as a number of chemokines and other proteins, some of which are known to enhance survival/anti-apoptosis of progenitors. Irradiation of ES cells enhanced release of some proteins and decreased release of others. IL-6, FGF-9, and TNF-alpha, not detected prior to irradiation was found after ES cells were irradiated. ES cell CM also stimulated CFU-GM colony formation. Thus, undifferentiated murine ES cells growing in the presence of LIF produce/release a number of biologically active interleukins, CSFs, chemokines, and other growth modulatory proteins, results which may be of physiological and/or practical significance.

  1. Regulation of Chemokine Expression by Lipopolysaccharide In Vitro and In Vivo

    DTIC Science & Technology

    2002-06-10

    Figure 1. Diagram of Enterobacterial LPS (A) and Lipid A (B) 4 Figure 2. LPS Signaling 8 Figure 3. Physiological Consequences of...MLV Moloney Murine Leukemia Virus MPL monophosphoryl lipid A MPO myeloperoxidase mRNA messenger ribonucleic acid MW molecular weight MyD88...chain, the core polysaccharide, and the lipid A domain (Figure 1A). The hydrophilic O-specific chain is a polymer of repeating oligosaccharide units

  2. Retinoic acid-induced differentiation of retrovirus-infected HL-60 cells is associated with enhanced transcription from the viral long terminal repeat

    SciTech Connect

    Collins, S.J.

    1988-11-01

    The author infected different human leukemic cell lines with an amphotropic retrovirus vector (designated PA317/N2) which confers G418 resistance and contains the Moloney murine leukemia virus long terminal repeat. In retrovirus-infected G418-resistant HL-60 cells, induction of granulocyte differentiation by retinoic acid was invariably accompanied by a marked increase (5- to 10-fold) in the transcriptional activity of the integrated retroviral long terminal repeat.

  3. Analysis of Breast Cell-Lineage Response Differences to Taxol Using a Novel Co-Culture System

    DTIC Science & Technology

    2005-06-01

    obtain immortalized cells are indicated by cell type followed by the introduced gene of interest. All infections are performed using human papilloma virus ...higher-flow peak corresponds to lower overall integrin is the main receptor of human papilloma virus type 16 VLP. numbers of cells, and therefore follow...type 16 (HPV type 16) under the transcriptional regulation of the moloney murine leukemia virus (MMLV) promoter sequence (12). The HPV E6 and E7

  4. Patient-derived xenotransplants can recapitulate the genetic driver landscape of acute leukemias.

    PubMed

    Wang, K; Sanchez-Martin, M; Wang, X; Knapp, K M; Koche, R; Vu, L; Nahas, M K; He, J; Hadler, M; Stein, E M; Tallman, M S; Donahue, A L; Frampton, G M; Lipson, D; Roels, S; Stephens, P J; Sanford, E M; Brennan, T; Otto, G A; Yelensky, R; Miller, V A; Kharas, M G; Levine, R L; Ferrando, A; Armstrong, S A; Krivtsov, A V

    2017-01-01

    Genomic studies have identified recurrent somatic mutations in acute leukemias. However, current murine models do not sufficiently encompass the genomic complexity of human leukemias. To develop preclinical models, we transplanted 160 samples from patients with acute leukemia (acute myeloid leukemia, mixed lineage leukemia, B-cell acute lymphoblastic leukemia, T-cell ALL) into immunodeficient mice. Of these, 119 engrafted with expected immunophenotype. Targeted sequencing of 374 genes and 265 frequently rearranged RNAs detected recurrent and novel genetic lesions in 48 paired primary tumor (PT) and patient-derived xenotransplant (PDX) samples. Overall, the frequencies of 274 somatic variant alleles correlated between PT and PDX samples, although the data were highly variable for variant alleles present at 0-10%. Seventeen percent of variant alleles were detected in either PT or PDX samples only. Based on variant allele frequency changes, 24 PT-PDX pairs were classified as concordant while the other 24 pairs showed various degree of clonal discordance. There was no correlation of clonal concordance with clinical parameters of diseases. Significantly more bone marrow samples than peripheral blood samples engrafted discordantly. These data demonstrate the utility of developing PDX banks for modeling human leukemia, and emphasize the importance of genomic profiling of PDX and patient samples to ensure concordance before performing mechanistic or therapeutic studies.

  5. Anticipation in familial leukemia

    SciTech Connect

    Horwitz, M.; Jarvik, G.P.; Goode, E.L.

    1996-11-01

    Anticipation refers to worsening severity or earlier age at onset with each generation for an inherited disease and primarily has been described for neurodegenerative illnesses resulting from expansion of trinucleotide repeats. We have tested for evidence of anticipation in familial leukemia. Of 49 affected individuals in nine families transmitting autosomal dominant acute myelogenous leukemia (AML), the mean age at onset is 57 years in the grandparental generation, 32 years in the parental generation, and 13 years in the youngest generation (P < .001). Of 21 parent-child pairs with AML, 19 show younger ages at onset in the child and demonstrate a mean decline in age at onset of 28 years (P < .001). Of 18 affected individuals from seven pedigrees with autosomal dominant chronic lymphocytic leukemia (CLL), the mean age at onset in the parental generation is 66 years versus 51 years in the youngest generation (P = .008). Of nine parent-child pairs with CLL, eight show younger ages at onset in the child and reveal a mean decline in age at onset of 21 years (P = .001). Inspection of rare pedigrees transmitting acute lymphocytic leukemia, chronic myelogenous leukemia, multiple types of leukemia, and lymphoma is also compatible with anticipation. Sampling bias is unlikely to explain these findings. This suggests that dynamic mutation of unstable DNA sequence repeats could be a common mechanism of inherited hematopoietic malignancy with implications for the role of somatic mutation in the more frequent sporadic cases. We speculate on three possible candidate genes for familial leukemia with anticipation: a locus on 21q22.1-22.2, CBL2 on 11q23.3, and CBFB or a nearby gene on 16q22. 55 refs., 4 figs.

  6. Hematopoietic overexpression of the transcription factor Erg induces lymphoid and erythro-megakaryocytic leukemia

    PubMed Central

    Carmichael, Catherine L.; Metcalf, Donald; Henley, Katya J.; Kruse, Elizabeth A.; Di Rago, Ladina; Mifsud, Sandra; Alexander, Warren S.; Kile, Benjamin T.

    2012-01-01

    The transcription factor encoded by the E-twenty-six (ETS)-related gene, ERG, is an essential regulator of hematopoietic stem cell function and a potent human oncoprotein. Enforced expression of ERG in murine hematopoietic cells leads to the development of a well-characterized lymphoid leukemia and a less well-defined non lymphoid disease. To clarify the latter, we generated murine bone marrow chimeras with enforced Erg expression in engrafted hematopoietic progenitor cells. As expected, these mice developed lymphoid leukemia. However, the previously reported non lymphoid disease that developed was shown to be a uniform, transplantable leukemia with both erythroid and megakaryocytic characteristics. In vivo, this disease had the overall appearance of an erythroleukemia, with an accumulation of immature erythroblasts that infiltrated the bone marrow, spleen, liver, and lung. However, when stimulated in vitro, leukemic cell clones exhibited both erythroid and megakaryocytic differentiation, suggesting that transformation occurred in a bipotential progenitor. Thus, in mice, Erg overexpression induces the development of not only lymphoid leukemia but also erythro-megakaryocytic leukemia. PMID:22936051

  7. Chronic lymphocytic leukemia: molecular genetics and animal models.

    PubMed

    Pekarsky, Y; Calin, G A; Aqeilan, R

    2005-01-01

    Chronic lymphocytic leukemia accounts for almost 30% of all adult leukemia cases in the United States and Western Europe. Although several common genomic abnormalities in CLL have been identified, mutational and functional analysis of corresponding genes so far have not proved their involvement in CLL. Our latest studies demonstrated functional involvement of Tcl1 oncoprotein and microRNA genes in the pathogenesis of CLL. Deregulated expression of Tcl1 in transgenic mice resulted in CLL. These CLL tumors showed abnormalities in expression of murine microRNA genes mmu-mir-15a and mmu-mir-16-1. Interestingly, human homologs of these genes, mir-15a and mir-16-1, located at the chromosome 13q14 are also deleted in human CLL samples. In this review we summarize and discuss these new developments. These recently emerged insights into the molecular mechanisms of CLL will allow for the development of new approaches to treat this disease.

  8. Identification of leukemia cell surface proteins in clams

    SciTech Connect

    Reinisch, C.L.; Smolowitz, R.; Miosky, D. Marine Biological Lab., Woods Hole, MA )

    1988-09-01

    Soft-shell clams, Mya arenaria, develop leukemias which, in the advanced stages of disease, kill the host. The authors laboratory has developed an extensive panel of murine monoclonal antibodies to leukemia cells of Mya, and has used these powerful reagents to diagnose the disease with extreme accuracy. They have now ascertained that one membrane-associated protein of approximately 200kD is immunodominant. The function of this protein, regulation of its production and potential site of synthesis are being evaluated. Monoclonal antibodies have also permitted the exploration of the mechanism of leukemogensis. They have evaluated the specific staining pattern of one monoclonal antibody, and have concluded that at least one ontogenic source of leukemic cells may be connective tissue cells lining the sinusoids. Whether or not exposure to severely polluted sites such as New Bedford Harbor stimulates the export of immature hemocytes which then become transformed is at least one possibility amenable to testing using the monoclonal reagents.

  9. Differential niche and Wnt requirements during acute myeloid leukemia progression.

    PubMed

    Lane, Steven W; Wang, Yingzi J; Lo Celso, Cristina; Ragu, Christine; Bullinger, Lars; Sykes, Stephen M; Ferraro, Francesca; Shterental, Sebastian; Lin, Charles P; Gilliland, D Gary; Scadden, David T; Armstrong, Scott A; Williams, David A

    2011-09-08

    Hematopoietic stem cells (HSCs) engage in complex bidirectional signals with the hematopoietic microenvironment (HM), and there is emerging evidence that leukemia stem cells (LSCs) may use similar interactions. Using a syngeneic retroviral model of MLL-AF9 induced acute myeloid leukemia (AML), we have identified 2 different stages of leukemia progression, propagated by "pre-LSCs" and established leukemia (LSCs) and compared the homing properties of these distinctive entities to that of normal HSCs. The homing and microlocalization of pre-LSCs was most similar to long-term HSCs and was dependent on cell-intrinsic Wnt signaling. In contrast, the homing of established LSCs was most similar to that of committed myeloid progenitors and distinct from HSCs. Although osteoblast-derived Dickkopf-1, a potent Wnt inhibitor known to impair HSC function, dramatically impaired normal HSC localization within the bone marrow, it did not affect pre-LSCs, LSC homing, or AML development. Mechanistically, cell-intrinsic Wnt activation was observed in human and murine AML samples, explaining the independence of MLL-AF9 LSCs from niche-derived Wnt signals. These data identify differential engagement of HM associated with leukemic progression and identify an LSC niche that is physically distinct and independent of the constraints of Wnt signaling that apply to normal HSCs.

  10. Differential niche and Wnt requirements during acute myeloid leukemia progression

    PubMed Central

    Lane, Steven W.; Wang, Yingzi J.; Lo Celso, Cristina; Ragu, Christine; Bullinger, Lars; Sykes, Stephen M.; Ferraro, Francesca; Shterental, Sebastian; Lin, Charles P.; Gilliland, D. Gary

    2011-01-01

    Hematopoietic stem cells (HSCs) engage in complex bidirectional signals with the hematopoietic microenvironment (HM), and there is emerging evidence that leukemia stem cells (LSCs) may use similar interactions. Using a syngeneic retroviral model of MLL-AF9 induced acute myeloid leukemia (AML), we have identified 2 different stages of leukemia progression, propagated by “pre-LSCs” and established leukemia (LSCs) and compared the homing properties of these distinctive entities to that of normal HSCs. The homing and microlocalization of pre-LSCs was most similar to long-term HSCs and was dependent on cell-intrinsic Wnt signaling. In contrast, the homing of established LSCs was most similar to that of committed myeloid progenitors and distinct from HSCs. Although osteoblast-derived Dickkopf-1, a potent Wnt inhibitor known to impair HSC function, dramatically impaired normal HSC localization within the bone marrow, it did not affect pre-LSCs, LSC homing, or AML development. Mechanistically, cell-intrinsic Wnt activation was observed in human and murine AML samples, explaining the independence of MLL-AF9 LSCs from niche-derived Wnt signals. These data identify differential engagement of HM associated with leukemic progression and identify an LSC niche that is physically distinct and independent of the constraints of Wnt signaling that apply to normal HSCs. PMID:21765021

  11. Final Report: Comparative Studies in the Field of Mouse and Human Leukemia, June 1, 1991 - October 31, 1994

    SciTech Connect

    Haas, Martin

    1998-12-01

    Early in the work on this grant the authors established that the growth factor-dependence of radiation-induced thymic leukemia cells was dependent on the autocrine/paracrine growth factor IL-4. Localized, thymic leukemias always grew by virtue of an IL-4-driven autocrine/paracrine pathway. They continued and investigated the mechanism of progression of the thymic leukemias to the later, disseminate disease. Linking the generation of disseminated leukemias to their growth factor-dependent status [10,11], they found that the development of growth factor-independence was associated with the dissemination of the leukemia from the thymus to other sites, e.g. spleen, lymphnodes, liver and kidney [9,8]. Indeed, all disseminated leukemias were composed of growth factor-independent cells. The generation of disseminated radiation-induced leukemia is associated with the loss of specific differentiation antigens and the mutation of the p53 tumor suppressor gene. The thymic, growth factor-independent leukemia carried non-mutated, wild type p53 [4]. These results suggested that it might be possible to influence the dissemination [6,7] of leukemia cell propagation in vivo by the re-introduction of wild type p53 into the leukemias cells. They could show that the transduction of genes encoding specific mutant p53 proteins enhanced their dissemination potential and, in addition, the transduction of constructs encoding wild type p53 reversed the disseminated phenotype--and the leukemic phenotype--of murine and human acute leukemia cells. As a result of the DOE grant, and to further study the gene-transduction approach for the inhibition of leukemia and other cancer cells, they developed an acute retroviral gene transfer system that was capable of the rapid generation of high-titer retroviral virions that were non-mutated and non-deleted [12]. This system has been supplied to dozens of laboratories in the country and is widely used in many research laboratories.

  12. Topoisomerase II and leukemia

    PubMed Central

    Pendleton, MaryJean; Lindsey, R. Hunter; Felix, Carolyn A.; Grimwade, David; Osheroff, Neil

    2014-01-01

    Type II topoisomerases are essential enzymes that modulate DNA under- and overwinding, knotting, and tangling. Beyond their critical physiological functions, these enzymes are the targets for some of the most widely prescribed anticancer drugs (topoisomerase II poisons) in clinical use. Topoisomerase II poisons kill cells by increasing levels of covalent enzyme-cleaved DNA complexes that are normal reaction intermediates. Drugs such as etoposide, doxorubicin, and mitoxantrone are frontline therapies for a variety of solid tumors and hematological malignancies. Unfortunately, their use is also associated with the development of specific leukemias. Regimens that include etoposide or doxorubicin are linked to the occurrence of acute myeloid leukemias that feature rearrangements at chromosomal band 11q23. Similar rearrangements are seen in infant leukemias and are associated with gestational diets that are high in naturally occurring topoisomerase II–active compounds. Finally, regimens that include mitoxantrone and epirubicin are linked to acute promyelocytic leukemias that feature t(15;17) rearrangements. The first part of this article will focus on type II topoisomerases and describe the mechanism of enzyme and drug action. The second part will discuss how topoisomerase II poisons trigger chromosomal breaks that lead to leukemia and potential approaches for dissociating the actions of drugs from their leukemogenic potential. PMID:24495080

  13. Obatoclax, Fludarabine, and Rituximab in Treating Patients With Previously Treated Chronic Lymphocytic Leukemia

    ClinicalTrials.gov

    2013-09-27

    B-cell Chronic Lymphocytic Leukemia; Leukemia; Prolymphocytic Leukemia; Refractory Chronic Lymphocytic Leukemia; Stage I Chronic Lymphocytic Leukemia; Stage II Chronic Lymphocytic Leukemia; Stage III Chronic Lymphocytic Leukemia; Stage IV Chronic Lymphocytic Leukemia

  14. RUNX1-ETO Leukemia.

    PubMed

    Lin, Shan; Mulloy, James C; Goyama, Susumu

    2017-01-01

    AML1-ETO leukemia is the most common cytogenetic subtype of acute myeloid leukemia, defined by the presence of t(8;21). Remarkable progress has been achieved in understanding the molecular pathogenesis of AML1-ETO leukemia. Proteomic surveies have shown that AML-ETO forms a stable complex with several transcription factors, including E proteins. Genome-wide transcriptome and ChIP-seq analyses have revealed the genes directly regulated by AML1-ETO, such as CEBPA. Several lines of evidence suggest that AML1-ETO suppresses endogenous DNA repair in cells to promote mutagenesis, which facilitates acquisition of cooperating secondary events. Furthermore, it has become increasingly apparent that a delicate balance of AML1-ETO and native AML1 is important to sustain the malignant cell phenotype. Translation of these findings into the clinical setting is just beginning.

  15. Tanespimycin and Cytarabine in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Chronic Myelogenous Leukemia, Chronic Myelomonocytic Leukemia, or Myelodysplastic Syndromes

    ClinicalTrials.gov

    2013-09-27

    Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes

  16. Leukemia in benzene workers.

    PubMed

    Rinsky, R A; Young, R J; Smith, A B

    1981-01-01

    To evaluate the possible association between occupational exposure to benzene and subsequent death from leukemia, the National Institute for Occupational Safety and Health (NIOSH) conducted a retrospective cohort mortality study of workers who had been exposed to benzene in the manufacture of rubber hydrochloride at two locations in Ohio. Ascertainment of vital status was accomplished for 98% of the cohort. Among 748 workers who had at least one day of exposure to benzene between 1940 and 1950, seven deaths from leukemia occurred; from United States death rates standardized for sex, age, and calendar time period, only 1.25 leukemia deaths would have been expected (standardized mortality ratio = 560; p less than 0.001). Mean duration of exposure to benzene was brief, and 437 (58%) of the cohort were exposed for less than 1 year. Evaluation of leukemia mortality for those workers exposed five or more years showed an SMR of 2100. All leukemia deaths were myelocytic or monocytic in cell type. Four additional cases of leukemia have been reorganized in workers at the study locations, but occurred in persons not encompassed by the strict definition of the cohort. Reconstruction of past exposures to benzene at the two locations indicates that in some areas of the plant airborne benzene concentrations rose occasionally to several hundred parts per million (ppm), but that for the most part, employee eight-hour time-weighted averages (TWA) fell within the limits considered permissible at the time of exposure. These data corroborate an initial analysis of the same cohort by Infante et al, and indicate that benzene is a human carcinogen at a range of exposures not greatly above the current legal standard.

  17. Side-stream cigarette smoke accentuates immunomodulation during murine AIDS.

    PubMed

    Zhang, Jin; Du Ester, En-Jie; Watson, Ronald Ross

    2002-05-01

    Side-stream cigarette smoke has become a hotly debated social, political, and scientific health and safety issue for nonsmokers. The harmful influences of side-stream cigarette smoke on human health are its adverse effects on the immune system, especially when already compromised by other agents. Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by human immunodeficiency virus (HIV). To facilitate studies, murine AIDS was induced in C57BL/6 mice by LP-BM5 murine leukemia virus infection, which mimics human AIDS. After 2 weeks of retroviral infection, the mice were exposed to side-stream cigarette smoke for 30 min, 5 days/week for 12 weeks using a side-stream cigarette smoke exposure system. Murine retrovirus infection reduced the in vitro proliferation of T lymphocytes stimulated by concanavalin A, increased the release of pro-inflammatory cytokine interleukin-6 (IL-6) tumor necrosis factor-alpha (TNF-alpha), increased the hepatic lipid peroxidation and decreased the alpha-tocopherol levels in liver, lung and heart. Concomitant side-stream cigarette smoke exposure for 12 weeks further inhibited the proliferation of T cells, increased the release of TNF-alpha, IL-6 cytokines and enhanced the hepatic lipid peroxidation from retrovirus infected mice. The loss of alpha-tocopherol was also further enhanced by side-stream cigarette smoke exposure during retrovirus infection. Our conclusions are that side-stream cigarette smoke induced increasing oxidative stress, reducing nutrient concentrations and suppressing immune function could make mice with murine AIDS more susceptible to opportunistic infections, potentially accelerating murine AIDS progression. Thus, the reduction of side-stream cigarette smoke exposure is an important health issue in AIDS patients to improve the quality and quantity of their lives.

  18. Chemopreventive effects of dietary eicosapentaenoic acid supplementation in experimental myeloid leukemia

    PubMed Central

    Finch, Emily R.; Kudva, Avinash K.; Quickel, Michael D.; Goodfield, Laura L.; Kennett, Mary J.; Whelan, Jay; Paulson, Robert F.; Prabhu, K. Sandeep

    2015-01-01

    Current therapies for treatment of myeloid leukemia do not eliminate leukemia stem cells (LSC), leading to disease relapse. In this study, we supplemented mice with eicosapentaenoic acid (EPA, C20:5), a polyunsaturated omega-3 fatty acid, at pharmacological levels, to examine if the endogenous metabolite, cyclopentenone prostaglandin delta-12 PGJ3 (Δ12-PGJ3), was effective in targeting LSCs in experimental leukemia. EPA supplementation for eight weeks resulted in enhanced endogenous production of Δ12-PGJ3 that was blocked by indomethacin, a cyclooxygenase inhibitor. Using a murine model of chronic myelogenous leukemia (CML) induced by bone marrow transplantation of BCR-ABL-expressing hematopoietic stem cells, mice supplemented with EPA showed a decrease in the LSC population, reduced splenomegaly and leukocytosis, when compared to mice on an oleic acid diet. Supplementation of CML mice carrying the T315I mutation (in BCR-ABL) with EPA resulted in a similar effect. Indomethacin blocked the EPA effect and increased the severity of BCR-ABL-induced CML and decreased apoptosis. Δ12-PGJ3 rescued indomethacin-treated BCR-ABL mice and decreased LSCs. Inhibition of hematopoietic-prostaglandin D synthase (H-PGDS) by HQL-79 in EPA-supplemented CML mice also blocked the effect of EPA. In addition, EPA supplementation was effective in a murine model of acute myeloid leukemia. Supplemented mice exhibited a decrease in leukemia burden and a decrease in the LSC colony-forming unit (LSC-CFU). The decrease in LSCs was confirmed through serial transplantation assays in all disease models. The results support a chemopreventive role for EPA in myeloid leukemia, which is dependent on the ability to efficiently convert EPA to endogenous cyclooxygenase-derived prostanoids, including Δ12-PGJ3. PMID:26290393

  19. Normal ABL1 is a tumor suppressor and therapeutic target in human and mouse leukemias expressing oncogenic ABL1 kinases.

    PubMed

    Dasgupta, Yashodhara; Koptyra, Mateusz; Hoser, Grazyna; Kantekure, Kanchan; Roy, Darshan; Gornicka, Barbara; Nieborowska-Skorska, Margaret; Bolton-Gillespie, Elisabeth; Cerny-Reiterer, Sabine; Müschen, Markus; Valent, Peter; Wasik, Mariusz A; Richardson, Christine; Hantschel, Oliver; van der Kuip, Heiko; Stoklosa, Tomasz; Skorski, Tomasz

    2016-04-28

    Leukemias expressing constitutively activated mutants of ABL1 tyrosine kinase (BCR-ABL1, TEL-ABL1, NUP214-ABL1) usually contain at least 1 normal ABL1 allele. Because oncogenic and normal ABL1 kinases may exert opposite effects on cell behavior, we examined the role of normal ABL1 in leukemias induced by oncogenic ABL1 kinases. BCR-ABL1-Abl1(-/-) cells generated highly aggressive chronic myeloid leukemia (CML)-blast phase-like disease in mice compared with less malignant CML-chronic phase-like disease from BCR-ABL1-Abl1(+/+) cells. Additionally, loss of ABL1 stimulated proliferation and expansion of BCR-ABL1 murine leukemia stem cells, arrested myeloid differentiation, inhibited genotoxic stress-induced apoptosis, and facilitated accumulation of chromosomal aberrations. Conversely, allosteric stimulation of ABL1 kinase activity enhanced the antileukemia effect of ABL1 tyrosine kinase inhibitors (imatinib and ponatinib) in human and murine leukemias expressing BCR-ABL1, TEL-ABL1, and NUP214-ABL1. Therefore, we postulate that normal ABL1 kinase behaves like a tumor suppressor and therapeutic target in leukemias expressing oncogenic forms of the kinase. © 2016 by The American Society of Hematology.

  20. Murine AIDS Protects Mice Against Experimental Cerebral Malaria: Down-Regulation by Interleukin 10 a T-Helper Type 1 CD4^+ Cell-Mediated Pathology

    NASA Astrophysics Data System (ADS)

    Eckwalanga, Michel; Marussig, Myriam; Dias Tavares, Marisa; Bouanga, Jean Claude; Hulier, Elisabeth; Henriette Pavlovitch, Jana; Minoprio, Paola; Portnoi, Denis; Renia, Laurent; Mazier, Dominique

    1994-08-01

    The retrovirus LP-BM5 murine leukemia virus induces murine AIDS in C57BL/6 mice that has many similarities with human AIDS; Plasmodium berghei ANKA causes experimental cerebral malaria in the same strain of mice. The outcome of malaria infection was studied in mice concurrently infected with the two pathogens. The retrovirus significantly reduced the gravity of the neurological manifestations associated with Plasmodium berghei ANKA infection. The protection against experimental cerebral malaria induced by murine AIDS increased with duration of viral infection and, hence, with the severity of the immunodeficiency. Interleukin 10, principally from splenic T cells, was shown to play a crucial role in this protection.

  1. AMPK protects leukemia-initiating cells in myeloid leukemias from metabolic stress in the bone marrow

    PubMed Central

    Saito, Yusuke; Chapple, Richard H.; Lin, Angelique; Kitano, Ayumi; Nakada, Daisuke

    2015-01-01

    SUMMARY How cancer cells adapt to metabolically adverse conditions in patients and strive to proliferate is a fundamental question in cancer biology. Here we show that AMP-activated protein kinase (AMPK), a metabolic checkpoint kinase, confers metabolic stress resistance to leukemia-initiating cells (LICs) and promotes leukemogenesis. Upon dietary restriction, MLL-AF9-induced murine AML activated AMPK and maintained leukemogenic potential. AMPK deletion significantly delayed leukemogenesis and depleted LICs by reducing the expression of glucose transporter 1 (Glut1), compromising glucose flux, and increasing oxidative stress and DNA damage. LICs were particularly dependent on AMPK to suppress oxidative stress in the hypoglycemic bone marrow environment. Strikingly, AMPK inhibition synergized with physiological metabolic stress caused by dietary restriction and profoundly suppressed leukemogenesis. Our results indicate that AMPK protects LICs from metabolic stress, and that combining AMPK inhibition with physiological metabolic stress potently suppresses AML by inducing oxidative stress and DNA damage. PMID:26440282

  2. Frequencies and prognostic impact of RAS mutations in MLL-rearranged acute lymphoblastic leukemia in infants

    PubMed Central

    Driessen, Emma M.C.; van Roon, Eddy H.J.; Spijkers-Hagelstein, Jill A.P.; Schneider, Pauline; de Lorenzo, Paola; Valsecchi, Maria Grazia; Pieters, Rob; Stam, Ronald W.

    2013-01-01

    Acute lymphoblastic leukemia in infants represents an aggressive malignancy associated with a high incidence (approx. 80%) of translocations involving the Mixed Lineage Leukemia (MLL) gene. Attempts to mimic Mixed Lineage Leukemia fusion driven leukemogenesis in mice raised the question whether these fusion proteins require secondary hits. RAS mutations are suggested as candidates. Earlier results on the incidence of RAS mutations in Mixed Lineage Leukemia-rearranged acute lymphoblastic leukemia are inconclusive. Therefore, we studied frequencies and relation with clinical parameters of RAS mutations in a large cohort of infant acute lymphoblastic leukemia patients. Using conventional sequencing analysis, we screened neuroblastoma RAS viral (v-ras) oncogene homolog gene (NRAS), v-Ki-ras Kirsten rat sarcoma viral oncogene homolog gene (KRAS), and v-raf murine sarcoma viral oncogene homolog B1 gene (BRAF) for mutations in a large cohort (n=109) of infant acute lymphoblastic leukemia patients and studied the mutations in relation to several clinical parameters, and in relation to Homeobox gene A9 expression and the presence of ALL1 fused gene 4-Mixed Lineage Leukemia (AF4-MLL). Mutations were detected in approximately 14% of all cases, with a higher frequency of approximately 24% in t(4;11)-positive patients (P=0.04). Furthermore, we identified RAS mutations as an independent predictor (P=0.019) for poor outcome in Mixed Lineage Leukemia-rearranged infant acute lymphoblastic leukemia, with a hazard ratio of 3.194 (95% confidence interval (CI):1.211–8.429). Also, RAS-mutated infants have higher white blood cell counts at diagnosis (P=0.013), and are more resistant to glucocorticoids in vitro (P<0.05). Finally, we demonstrate that RAS mutations, and not the lack of Homeobox gene A9 expression nor the expression of AF4-MLL are associated with poor outcome in t(4;11)-rearranged infants. We conclude that the presence of RAS mutations in Mixed Lineage Leukemia

  3. Leukemia and Benzene

    PubMed Central

    Snyder, Robert

    2012-01-01

    Excessive exposure to benzene has been known for more than a century to damage the bone marrow resulting in decreases in the numbers of circulating blood cells, and ultimately, aplastic anemia. Of more recent vintage has been the appreciation that an alternative outcome of benzene exposure has been the development of one or more types of leukemia. While many investigators agree that the array of toxic metabolites, generated in the liver or in the bone marrow, can lead to traumatic bone marrow injury, the more subtle mechanisms leading to leukemia have yet to be critically dissected. This problem appears to have more general interest because of the recognition that so-called “second cancer” that results from prior treatment with alkylating agents to yield tumor remissions, often results in a type of leukemia reminiscent of benzene-induced leukemia. Furthermore, there is a growing literature attempting to characterize the fine structure of the marrow and the identification of so called “niches” that house a variety of stem cells and other types of cells. Some of these “niches” may harbor cells capable of initiating leukemias. The control of stem cell differentiation and proliferation via both inter- and intra-cellular signaling will ultimately determine the fate of these transformed stem cells. The ability of these cells to avoid checkpoints that would prevent them from contributing to the leukemogenic response is an additional area for study. Much of the study of benzene-induced bone marrow damage has concentrated on determining which of the benzene metabolites lead to leukemogenesis. The emphasis now should be directed to understanding how benzene metabolites alter bone marrow cell biology. PMID:23066403

  4. Cloning and characterization of a murine SIL gene

    SciTech Connect

    Collazo-Garcia, N.; Scherer, P.; Aplan, P.D.

    1995-12-10

    The human SIL gene is disrupted by a site-specific interstitial deletion in 25% of children with T-cell acute lymphoblastic leukemia. Since transcriptionally active genes are prone to recombination events, the recurrent nature of this lesion suggests that the SIL gene product is transcriptionally active in the cell type that undergoes this interstitial deletion and that the SIL gene product may play a role in normal lymphoid development. To facilitate studies of SIL gene function, we have cloned and characterized a murine SIL gene. The predicted murine SIL protein is 75% identical to the human gene, with good homology throughout the open reading frame. An in vitro translated SIL cDNA generated a protein slightly larger than the predicted 139-kDa protein. Although a prior report detected SIL mRNA expression exclusively in hematopoietic tissues, a sensitive RT-PCR assay demonstrated SIL expression to be ubiquitous, detectable in all tissues examined. Since the RT-PCR assay suggested that SIL mRNA expression was higher in rapidly proliferating tissues, we assayed SIL mRNA expression using a murine erythroleukemia model of terminal differentiation and found it to be dramatically decreased in conjunction with terminal differentiation. These studies demonstrate that the human SIL gene product is quite well conserved in rodents and suggest that the SIL gene product may play a role in cell proliferation. 26 refs., 6 figs.

  5. What Are the Key Statistics about Acute Lymphocytic Leukemia?

    MedlinePlus

    ... Leukemia (ALL) What Are the Key Statistics About Acute Lymphocytic Leukemia? The American Cancer Society’s estimates for acute lymphocytic ... Acute Lymphocytic Leukemia Research and Treatment? More In Acute Lymphocytic Leukemia About Acute Lymphocytic Leukemia Causes, Risk Factors, and ...

  6. Do We Know What Causes Chronic Myelomonocytic Leukemia?

    MedlinePlus

    ... Prevention Do We Know What Causes Chronic Myelomonocytic Leukemia? Some cases of chronic myelomonocytic leukemia (CMML) are ... Myelomonocytic Leukemia Be Prevented? More In Chronic Myelomonocytic Leukemia About Chronic Myelomonocytic Leukemia Causes, Risk Factors, and ...

  7. The cell polarity determinant CDC42 controls division symmetry to block leukemia cell differentiation.

    PubMed

    Mizukawa, Benjamin; O'Brien, Eric; Moreira, Daniel C; Wunderlich, Mark; Hochstetler, Cindy L; Duan, Xin; Liu, Wei; Orr, Emily; Grimes, H Leighton; Mulloy, James C; Zheng, Yi

    2017-09-14

    As a central regulator of cell polarity, the activity of CDC42 GTPase is tightly controlled in maintaining normal hematopoietic stem and progenitor cell (HSC/P) functions. We found that transformation of HSC/P to acute myeloid leukemia (AML) is associated with increased CDC42 expression and activity in leukemia cells. In a mouse model of AML, the loss of Cdc42 abrogates MLL-AF9-induced AML development. Furthermore, genetic ablation of CDC42 in both murine and human MLL-AF9 (MA9) cells decreased survival and induced differentiation of the clonogenic leukemia-initiating cells. We show that MLL-AF9 leukemia cells maintain cell polarity in the context of elevated Cdc42-guanosine triphosphate activity, similar to nonmalignant, young HSC/Ps. The loss of Cdc42 resulted in a shift to depolarized AML cells that is associated with a decrease in the frequency of symmetric and asymmetric cell divisions producing daughter cells capable of self-renewal. Importantly, we demonstrate that inducible CDC42 suppression in primary human AML cells blocks leukemia progression in a xenograft model. Thus, CDC42 loss suppresses AML cell polarity and division asymmetry, and CDC42 constitutes a useful target to alter leukemia-initiating cell fate for differentiation therapy. © 2017 by The American Society of Hematology.

  8. Pharmacologic inhibition of fatty acid oxidation sensitizes human leukemia cells to apoptosis induction

    PubMed Central

    Samudio, Ismael; Harmancey, Romain; Fiegl, Michael; Kantarjian, Hagop; Konopleva, Marina; Korchin, Borys; Kaluarachchi, Kumar; Bornmann, William; Duvvuri, Seshagiri; Taegtmeyer, Heinrich; Andreeff, Michael

    2009-01-01

    The traditional view is that cancer cells predominately produce ATP by glycolysis, rather than by oxidation of energy-providing substrates. Mitochondrial uncoupling — the continuing reduction of oxygen without ATP synthesis — has recently been shown in leukemia cells to circumvent the ability of oxygen to inhibit glycolysis, and may promote the metabolic preference for glycolysis by shifting from pyruvate oxidation to fatty acid oxidation (FAO). Here we have demonstrated that pharmacologic inhibition of FAO with etomoxir or ranolazine inhibited proliferation and sensitized human leukemia cells — cultured alone or on bone marrow stromal cells — to apoptosis induction by ABT-737, a molecule that releases proapoptotic Bcl-2 proteins such as Bak from antiapoptotic family members. Likewise, treatment with the fatty acid synthase/lipolysis inhibitor orlistat also sensitized leukemia cells to ABT-737, which supports the notion that fatty acids promote cell survival. Mechanistically, we generated evidence suggesting that FAO regulates the activity of Bak-dependent mitochondrial permeability transition. Importantly, etomoxir decreased the number of quiescent leukemia progenitor cells in approximately 50% of primary human acute myeloid leukemia samples and, when combined with either ABT-737 or cytosine arabinoside, provided substantial therapeutic benefit in a murine model of leukemia. The results support the concept of FAO inhibitors as a therapeutic strategy in hematological malignancies. PMID:20038799

  9. Radiation-induced leukemia: Comparative studies in mouse and man

    SciTech Connect

    Haas, M.

    1991-01-01

    We now have a clear understanding of the mechanism by which radiation-induced (T-cell) leukemia occurs. In irradiated mice (radiation-induced thymic leukemia) and in man (acute lymphoblastic T-cell leukemia, T-ALL) the mechanism of leukemogenesis is surprisingly similar. Expressed in the most elementary terms, T-cell leukemia occurs when T-cell differentiation is inhibited by a mutation, and pre-T cells attempt but fail to differentiate in the thymus. Instead of leaving the thymus for the periphery as functional T-cells they continue to proliferate in the thymus. The proliferating pre- (pro-) T-cells constitute the (early) acute T-cell leukemia (A-TCL). This model for the mechanism of T-cell leukemogenesis accounts for all the properties of both murine and human A-TCL. Important support for the model has recently come from work by Ilan Kirsch and others, who have shown that mutations/deletions in the genes SCL (TAL), SIL, and LCK constitute primary events in the development of T-ALL, by inhibiting differentiation of thymic pre- (pro-) T-cells. This mechanism of T-cell leukemogenesis brings several specific questions into focus: How do early A-TCL cells progress to become potently tumorigenic and poorly treatable Is it feasible to genetically suppress early and/or progressed A-TCL cells What is the mechanism by which the differentiation-inhibited (leukemic) pre-T cells proliferate During the first grant year we have worked on aspects of all three questions.

  10. Genetics Home Reference: chronic myeloid leukemia

    MedlinePlus

    ... Home Health Conditions chronic myeloid leukemia chronic myeloid leukemia Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Chronic myeloid leukemia is a slow-growing cancer of the blood- ...

  11. Treating Chronic Myeloid Leukemia by Phase

    MedlinePlus

    ... Myeloid Leukemia Targeted Therapies for Chronic Myeloid Leukemia Interferon Therapy for Chronic Myeloid Leukemia Chemotherapy for Chronic ... to help decide what drug would be best. Interferon or chemotherapy (chemo) may be tried for those ...

  12. Gemtuzumab Ozogamicin in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia or Acute Promyelocytic Leukemia

    ClinicalTrials.gov

    2017-02-20

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Promyelocytic Leukemia (M3); Childhood Acute Promyelocytic Leukemia (M3); Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Myeloid Leukemia

  13. AMPK Protects Leukemia-Initiating Cells in Myeloid Leukemias from Metabolic Stress in the Bone Marrow.

    PubMed

    Saito, Yusuke; Chapple, Richard H; Lin, Angelique; Kitano, Ayumi; Nakada, Daisuke

    2015-11-05

    How cancer cells adapt to metabolically adverse conditions in patients and strive to proliferate is a fundamental question in cancer biology. Here we show that AMP-activated protein kinase (AMPK), a metabolic checkpoint kinase, confers metabolic stress resistance to leukemia-initiating cells (LICs) and promotes leukemogenesis. Upon dietary restriction, MLL-AF9-induced murine acute myeloid leukemia (AML) activated AMPK and maintained leukemogenic potential. AMPK deletion significantly delayed leukemogenesis and depleted LICs by reducing the expression of glucose transporter 1 (Glut1), compromising glucose flux, and increasing oxidative stress and DNA damage. LICs were particularly dependent on AMPK to suppress oxidative stress in the hypoglycemic bone marrow environment. Strikingly, AMPK inhibition synergized with physiological metabolic stress caused by dietary restriction and profoundly suppressed leukemogenesis. Our results indicate that AMPK protects LICs from metabolic stress and that combining AMPK inhibition with physiological metabolic stress potently suppresses AML by inducing oxidative stress and DNA damage. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. MS-275 and Azacitidine in Treating Patients With Myelodysplastic Syndromes, Chronic Myelomonocytic Leukemia, or Acute Myeloid Leukemia

    ClinicalTrials.gov

    2017-01-31

    Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndrome; Leukemia; Previously Treated Myelodysplastic Syndrome; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndrome; Untreated Adult Acute Myeloid Leukemia

  15. Mouse models for pre-clinical drug testing in leukemia.

    PubMed

    Bhatia, Sanil; Daschkey, Svenja; Lang, Franziska; Borkhardt, Arndt; Hauer, Julia

    2016-11-01

    The development of novel drugs which specifically target leukemic cells, with the overall aim to increase complete remission and to reduce toxicity and morbidity, is the most important prerequisite for modern leukemia treatment. In this regard, the current transition rate of potential novel drugs from bench to bedside is remarkably low. Although many novel drugs show promising data in vitro and in vivo, testing of these medications in clinical phase I trials is often sobering with intolerable toxic side effects leading to failure in FDA approval. Areas covered: In this review, the authors discuss the development of murine model generation in the context of targeted therapy development for the treatment of childhood leukemia, aiming to decrease the attrition rate of progressively complex targeted therapies ranging from small molecules to cell therapy. As more complex therapeutic approaches develop, more complex murine models are needed, to recapitulate closely the human phenotype. Expert opinion: Combining xenograft models for efficacy testing and GEMMs for toxicity testing will be a global approach for pre-clinical testing of complex therapeutics and will contribute to the clinical approval of novel compounds. Finally, this approach is likely to increase clinical approval of novel compounds.

  16. Phase I Dose-Escalation Trial of Clofarabine Followed by Escalating Doses of Fractionated Cyclophosphamide in Children With Relapsed or Refractory Acute Leukemias

    ClinicalTrials.gov

    2010-09-21

    Myelodysplastic Syndrome; Acute Myeloid Leukemia; Myeloproliferative Disorders; Acute Lymphocytic Leukemia; Acute Promyelocytic Leukemia; Acute Leukemia; Chronic Myelogenous Leukemia; Myelofibrosis; Chronic Myelomonocytic Leukemia; Juvenile Myelomonocytic Leukemia

  17. Temsirolimus and Imatinib Mesylate in Treating Patients With Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2013-01-11

    Accelerated Phase Chronic Myelogenous Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Phase Chronic Myelogenous Leukemia; Relapsing Chronic Myelogenous Leukemia

  18. Imatinib Mesylate and Decitabine in Treating Patients With Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2013-01-22

    Accelerated Phase Chronic Myelogenous Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Childhood Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Relapsing Chronic Myelogenous Leukemia

  19. Sox4 is a key oncogenic target in C/EBPα mutant Acute Myeloid Leukemia

    PubMed Central

    Zhang, Hong; Alberich-Jordà, Meritxell; Amabile, Giovanni; Yang, Henry; Staber, Philipp B.; DiRuscio, Annalisa; Welner, Rob; Ebralidze, Alexander; Zhang, Junyan; Levantini, Elena; Lefebvre, Véronique; Valk, Peter J.M.; Delwel, Ruud; Hoogenkamp, Maarten; Nerlov, Claus; Cammenga, Jörg; Saez, Borja; Scadden, David T.; Bonifer, Constanze

    2014-01-01

    Summary Mutation or epigenetic silencing of the transcription factor C/EBPα is observed in ~10% of patients with acute myeloid leukemia (AML). In both cases, a common global gene expression profile is observed, but down-stream targets relevant for leukemogenesis are not known. Here we identify Sox4 as a direct target of C/EBPα whereby its expression is inversely correlated with C/EBPα activity. Downregulation of Sox4 abrogated increased self-renewal of leukemic cells and restored their differentiation. Gene expression profiles of leukemia initiating cells (LICs) from both Sox4 overexpression and murine C/EBPα mutant AML models clustered together, but differed from other types of AML. Our data demonstrate that Sox4 overexpression resulting from C/EBPα inactivation contributes to the development of leukemia with a distinct LIC phenotype. PMID:24183681

  20. Clinical advances in the management of chronic myelogenous leukemia: focus on bosutinib and patient considerations.

    PubMed

    Sweet, Kendra; Pinilla-Ibarz, Javier; Zhang, Ling

    2014-01-01

    The treatment for chronic myeloid leukemia has changed significantly over the past 15 years, and as of now, there are five BCR-ABL1 (breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1) tyrosine kinase inhibitors that have gained approval for treatment of this disease. All five are very effective drugs, and the decision surrounding which to use in specific patients is based on numerous factors. Bosutinib is one of the newer tyrosine kinase inhibitors to gain approval, and has been studied in the first-line setting as well as after failure of other tyrosine kinase inhibitors. It is an SRC-ABL1 (steroid receptor co-activator-ABL1) inhibitor that works in the presence of most kinase domain mutations. The primary side effects of bosutinib are gastrointestinal upsets. In the appropriate clinical setting, bosutinib can be considered a valuable addition to the armamentarium of treatments available for chronic myeloid leukemia.

  1. Mifepristone causing complete remission of rapidly advancing leukemia with measurement of progesterone-induced blocking factor.

    PubMed

    Check, Jerome H; Check, Diane; Cohen, Rachael; Sarumi, Mojirayo

    2014-05-01

    Mifepristone has been demonstrated to cause palliation from murine and human cancer, even in cancers not known to be positive for expression of progesterone receptors. The aim of the present study was to determine if rapidly advancing chronic lymphocytic leukemia responds to mifepristone therapy, and if so, is this effect related to increased expression of the progesterone-induced blocking factor? An 81-year-old woman with chronic lymphocytic leukemia whose condition progressed to the acute rapidly progressing stage agreed to be exclusively treated orally with 200 mg mifepristone daily. The patient showed a dramatic improvement after a short exposure time to mifepristone. Complete remission has persisted so far for 12 months on exclusive mifepristone therapy. Her PIBF levels were normal before mifepristone therapy and did not change after treatment. Mifepristone can provide marked improvement of human leukemia even in the absence of increased serum PIBF levels.

  2. MLL1 and DOT1L cooperate with meningioma-1 to induce acute myeloid leukemia

    PubMed Central

    Riedel, Simone S.; Haladyna, Jessica N.; Bezzant, Matthew; Stevens, Brett; Pollyea, Daniel A.; Sinha, Amit U.; Armstrong, Scott A.; Wei, Qi; Pollock, Roy M.; Daigle, Scott R.; Jordan, Craig T.; Ernst, Patricia; Bernt, Kathrin M.

    2016-01-01

    Meningioma-1 (MN1) overexpression is frequently observed in patients with acute myeloid leukemia (AML) and is predictive of poor prognosis. In murine models, forced expression of MN1 in hematopoietic progenitors induces an aggressive myeloid leukemia that is strictly dependent on a defined gene expression program in the cell of origin, which includes the homeobox genes Hoxa9 and Meis1 as key components. Here, we have shown that this program is controlled by two histone methyltransferases, MLL1 and DOT1L, as deletion of either Mll1 or Dot1l in MN1-expressing cells abrogated the cell of origin–derived gene expression program, including the expression of Hoxa cluster genes. In murine models, genetic inactivation of either Mll1 or Dot1l impaired MN1-mediated leukemogenesis. We determined that HOXA9 and MEIS1 are coexpressed with MN1 in a subset of clinical MN1hi leukemia, and human MN1hi/HOXA9hi leukemias were sensitive to pharmacologic inhibition of DOT1L. Together, these data point to DOT1L as a potential therapeutic target in MN1hi AML. In addition, our findings suggest that epigenetic modulation of the interplay between an oncogenic lesion and its cooperating developmental program has therapeutic potential in AML. PMID:26927674

  3. Donor cell leukemia.

    PubMed

    Ruiz-Arguelles, Alejandro

    2012-04-01

    Minimal residual disease refers to the tumour cells that are still present in a given patient after completion of a therapeutic scheme. The demonstration and quantification of residual neoplastic cells has a crucial impact in clinical decision making, for it might prompt continuation of treatment, while the absence of such cells might serve as evidence to withdraw therapy. Therefore, both sensitivity and specificity of the methods used to unravel residual neoplastic cells must be highly reliable and robust. Flow cytometry has been widely used for this purpose, and its clinical performance depends mainly on the criteria of interpretation, rather than in the technique by itself; molecular biology techniques have proved to be highly sensitive and specific but unfortunately they cannot be used in all patients or in all types of leukemia. Finally, the development of donor cell leukemia in transplanted patients, might mimic residual disease and add more confusion to an already controversial issue. These topics are discussed in this paper.

  4. Mast cell leukemia.

    PubMed

    Georgin-Lavialle, Sophie; Lhermitte, Ludovic; Dubreuil, Patrice; Chandesris, Marie-Olivia; Hermine, Olivier; Damaj, Gandhi

    2013-02-21

    Mast cell leukemia (MCL) is a very rare form of aggressive systemic mastocytosis accounting for < 1% of all mastocytosis. It may appear de novo or secondary to previous mastocytosis and shares more clinicopathologic aspects with systemic mastocytosis than with acute myeloid leukemia. Symptoms of mast cell activation-involvement of the liver, spleen, peritoneum, bones, and marrow-are frequent. Diagnosis is based on the presence of ≥ 20% atypical mast cells in the marrow or ≥ 10% in the blood; however, an aleukemic variant is frequently encountered in which the number of circulating mast cells is < 10%. The common phenotypic features of pathologic mast cells encountered in most forms of mastocytosis are unreliable in MCL. Unexpectedly, non-KIT D816V mutations are frequent and therefore, complete gene sequencing is necessary. Therapy usually fails and the median survival time is < 6 months. The role of combination therapies and bone marrow transplantation needs further investigation.

  5. IMMUNOTHERAPY IN ACUTE LEUKEMIA

    PubMed Central

    Leung, Wing

    2010-01-01

    Recent advances in immunotherapy of cancer may represent a successful example in translational research, in which progress in knowledge and technology in immunology has lead to new strategies of immunotherapy, and even past failure in many clinical trials have led to a better understanding of basic cancer immunobiology. This article reviews the latest concepts in antitumor immunology and its application in the treatment of cancer, with particular focus on acute leukemia. PMID:19100371

  6. Phase 1 Study of Terameprocol (EM-1421) in Patients With Leukemia

    ClinicalTrials.gov

    2016-02-20

    Leukemias; Acute Myeloid Leukemia (AML); Acute Lymphocytic Leukemia (ALL); Adult T Cell Leukemia (ATL); Chronic Myeloid Leukemia (CML-BP); Chronic Lymphocytic Leukemia (CLL); Myelodysplastic Syndrome (MDS); Chronic Myelomonocytic Leukemia (CMML)

  7. SB-715992 in Treating Patients With Acute Leukemia, Chronic Myelogenous Leukemia, or Advanced Myelodysplastic Syndromes

    ClinicalTrials.gov

    2013-01-10

    Acute Undifferentiated Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Acute Promyelocytic Leukemia (M3); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Blastic Phase Chronic Myelogenous Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes; Untreated Adult Acute Myeloid Leukemia

  8. Tumour-Associated Transplantation Antigens of Neoplasms Induced by a Naturally Occurring Murine Sarcoma Virus (FBJ-MSV)

    PubMed Central

    Jones, David B.; Moore, Michael

    1973-01-01

    FBJ osteosarcoma virus (FBJ-MSV) isolated originally from a spontaneously arising osteosarcoma in a CF1 mouse is the only known naturally occurring murine sarcoma virus (MSV). It is unique among strains of MSV in producing primarily sarcomata in mice. The capacity of tumour cells transformed in vivo by this agent to elicit specific transplantation immunity in syngeneic hosts was investigated. A low level of resistance (104-105 cells) was consistently induced by implantation of x-irradiated (15,000 rad) tumours or surgical excision of developing subcutaneous grafts. By contrast intraperitoneal inoculation of virus containing cellfree extracts of FBJ-MSV sarcomata was a far less effective immunization procedure. Confirmatory evidence for the antigenicity of these neoplasms was obtained in tests in which preincubation of tumour cells with lymphoid cells from specifically immune donors inhibited in vivo outgrowth of the FBJ-MSV cells in untreated syngeneic recipients. The induction of host resistance to FBJ-MSV cells by immunization with identical and independently-induced FBJ-MSV tumours established that FBJ-MSV cells possess common cell surface antigenic specificities in a manner analogous to those of experimental neoplasms induced by other oncogenic DNA and RNA viruses. Since FBJ-MSV cells release infectious virus it was not possible in this system to establish whether the tumour-rejection antigen was cellular or virion in nature. The antigenic weakness of FBJ-MSV cells in syngeneic hosts is comparable with that of virus-induced murine leukaemias of the Gross (G) or “wild” type subgroup to which category FBJ-MSV also belongs. These features suggest that FBJ-MSV exemplifies naturally occurring sarcomagenic viruses more closely than those of the Friend-Moloney-Rauscher-Graffi (FMRGr) subgroup which in general induce highly antigenic neoplasms. PMID:4516007

  9. Tumor suppressors BTG1 and IKZF1 cooperate during mouse leukemia development and increase relapse risk in B-cell precursor acute lymphoblastic leukemia patients.

    PubMed

    Scheijen, Blanca; Boer, Judith M; Marke, René; Tijchon, Esther; van Ingen Schenau, Dorette; Waanders, Esmé; van Emst, Liesbeth; van der Meer, Laurens T; Pieters, Rob; Escherich, Gabriele; Horstmann, Martin A; Sonneveld, Edwin; Venn, Nicola; Sutton, Rosemary; Dalla-Pozza, Luciano; Kuiper, Roland P; Hoogerbrugge, Peter M; den Boer, Monique L; van Leeuwen, Frank N

    2017-03-01

    Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis. In a large discovery cohort of 533 childhood B-cell precursor acute lymphoblastic leukemia patients, we observed that single-copy losses of BTG1 were significantly enriched in IKZF1-deleted B-cell precursor acute lymphoblastic leukemia (P=0.007). While BTG1 deletions alone had no impact on prognosis, the combined presence of BTG1 and IKZF1 deletions was associated with a significantly lower 5-year event-free survival (P=0.0003) and a higher 5-year cumulative incidence of relapse (P=0.005), when compared with IKZF1-deleted cases without BTG1 aberrations. In contrast, other copy number losses commonly observed in B-cell precursor acute lymphoblastic leukemia, such as CDKN2A/B, PAX5, EBF1 or RB1, did not affect the outcome of IKZF1-deleted acute lymphoblastic leukemia patients. To establish whether the combined loss of IKZF1 and BTG1 function cooperate in leukemogenesis, Btg1-deficient mice were crossed onto an Ikzf1 heterozygous background. We observed that loss of Btg1 increased the tumor incidence of Ikzf1(+/-) mice in a dose-dependent manner. Moreover, murine B cells deficient for Btg1 and Ikzf1(+/-) displayed increased resistance to glucocorticoids, but not to other chemotherapeutic drugs. Together, our results identify BTG1 as a tumor suppressor in leukemia that, when deleted, strongly enhances the risk of relapse in IKZF1-deleted B-cell precursor acute lymphoblastic leukemia, and augments the glucocorticoid resistance phenotype mediated by the loss of IKZF1 function. Copyright© Ferrata Storti Foundation.

  10. Acute myeloid leukemia creates an arginase-dependent immunosuppressive microenvironment

    PubMed Central

    Mussai, Francis; De Santo, Carmela; Abu-Dayyeh, Issa; Booth, Sarah; Quek, Lynn; McEwen-Smith, Rosanna M.; Qureshi, Amrana; Dazzi, Francesco; Vyas, Paresh

    2013-01-01

    Acute myeloid leukemia (AML) is the most common acute leukemia in adults and the second most common frequent leukemia of childhood. Patients may present with lymphopenia or pancytopenia at diagnosis. We investigated the mechanisms by which AML causes pancytopenia and suppresses patients’ immune response. This study identified for the first time that AML blasts alter the immune microenvironment through enhanced arginine metabolism. Arginase II is expressed and released from AML blasts and is present at high concentrations in the plasma of patients with AML, resulting in suppression of T-cell proliferation. We extended these results by demonstrating an arginase-dependent ability of AML blasts to polarize surrounding monocytes into a suppressive M2-like phenotype in vitro and in engrafted nonobese diabetic–severe combined immunodeficiency mice. In addition, AML blasts can suppress the proliferation and differentiation of murine granulocyte-monocyte progenitors and human CD34+ progenitors. Finally, the study showed that the immunosuppressive activity of AML blasts can be modulated through small-molecule inhibitors of arginase and inducible nitric oxide synthase, suggesting a novel therapeutic target in AML. The results strongly support the hypothesis that AML creates an immunosuppressive microenvironment that contributes to the pancytopenia observed at diagnosis. PMID:23733335

  11. Childhood Leukemia and Primary Prevention

    PubMed Central

    Whitehead, Todd P.; Metayer, Catherine; Wiemels, Joseph L.; Singer, Amanda W.; Miller, Mark D.

    2016-01-01

    Leukemia is the most common pediatric cancer, affecting 3,800 children per year in the United States. Its annual incidence has increased over the last decades, especially among Latinos. Although most children diagnosed with leukemia are now cured, many suffer long-term complications, and primary prevention efforts are urgently needed. The early onset of leukemia – usually before age five – and the presence at birth of “pre-leukemic” genetic signatures indicate that pre- and postnatal events are critical to the development of the disease. In contrast to most pediatric cancers, there is a growing body of literature – in the United States and internationally – that has implicated several environmental, infectious, and dietary risk factors in the etiology of childhood leukemia, mainly for acute lymphoblastic leukemia, the most common subtype. For example, exposures to pesticides, tobacco smoke, solvents, and traffic emissions have consistently demonstrated positive associations with the risk of developing childhood leukemia. In contrast, intake of vitamins and folate supplementation during the pre-conception period or pregnancy, breastfeeding, and exposure to routine childhood infections have been shown to reduce the risk of childhood leukemia. Some children may be especially vulnerable to these risk factors, as demonstrated by a disproportionate burden of childhood leukemia in the Latino population of California. The evidence supporting the associations between childhood leukemia and its risk factors – including pooled analyses from around the world and systematic reviews – is strong; however, the dissemination of this knowledge to clinicians has been limited. To protect children’s health, it is prudent to initiate programs designed to alter exposure to well-established leukemia risk factors rather than to suspend judgement until no uncertainty remains. Primary prevention programs for childhood leukemia would also result in the significant co

  12. A screening-based approach to circumvent tumor microenvironment-driven intrinsic resistance to BCR-ABL+ inhibitors in Ph+ acute lymphoblastic leukemia.

    PubMed

    Singh, Harpreet; Shelat, Anang A; Singh, Amandeep; Boulos, Nidal; Williams, Richard T; Guy, R Kiplin

    2014-01-01

    Signaling by the BCR-ABL fusion kinase drives Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Despite their clinical activity in many patients with CML, the BCR-ABL kinase inhibitors (BCR-ABL-KIs) imatinib, dasatinib, and nilotinib provide only transient leukemia reduction in patients with Ph+ ALL. While host-derived growth factors in the leukemia microenvironment have been invoked to explain this drug resistance, their relative contribution remains uncertain. Using genetically defined murine Ph+ ALL cells, we identified interleukin 7 (IL-7) as the dominant host factor that attenuates response to BCR-ABL-KIs. To identify potential combination drugs that could overcome this IL-7-dependent BCR-ABL-KI-resistant phenotype, we screened a small-molecule library including Food and Drug Administration-approved drugs. Among the validated hits, the well-tolerated antimalarial drug dihydroartemisinin (DHA) displayed potent activity in vitro and modest in vivo monotherapy activity against engineered murine BCR-ABL-KI-resistant Ph+ ALL. Strikingly, cotreatment with DHA and dasatinib in vivo strongly reduced primary leukemia burden and improved long-term survival in a murine model that faithfully captures the BCR-ABL-KI-resistant phenotype of human Ph+ ALL. This cotreatment protocol durably cured 90% of treated animals, suggesting that this cell-based screening approach efficiently identified drugs that could be rapidly moved to human clinical testing.

  13. A screening based approach to circumvent tumor microenvironment-driven intrinsic resistance to BCR-ABL+ inhibitors in Ph+ acute lymphoblastic leukemia

    PubMed Central

    Singh, Harpreet; Shelat, Anang A.; Singh, Amandeep; Boulos, Nidal; Williams, Richard T.; Guy, R. Kiplin

    2014-01-01

    Signaling by the BCR-ABL fusion kinase drives Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Despite their clinical activity in many patients with CML, the BCR-ABL kinase inhibitors (BCR-ABL-KIs) imatinib, dasatinib, and nilotinib provide only transient leukemia reduction in patients in Ph+ ALL. While host-derived growth factors present in the leukemia microenvironment have been invoked to explain this drug resistance, their relative contribution remains uncertain. Using genetically-defined murine Ph+ ALL cells, we identified Interleukin 7 (IL-7) as the dominant host-factor that attenuates response to BCR-ABL-KIs. To identify potential combination drugs that could overcome this IL-7-dependent BCR-ABL-KI-resistant phenotype, we screened a small molecule library including FDA-approved drugs. Among the validated hits, the well-tolerated anti-malarial drug dihydroartemisinin (DHA) displayed potent activity in vitro and modest in vivo monotherapy activity against engineered murine BCR-ABL-KI–resistant Ph+ ALL. Strikingly, co-treatment with DHA and dasatinib in vivo strongly reduced primary leukemia burden and improved long-term survival in a murine model that faithfully captures the BCR-ABL-KI-resistant phenotype of human Ph+ ALL. This co-treatment protocol durably cured 90% of treated animals, suggesting that this cell-based screening approach efficiently identified drugs that could be rapidly moved to human clinical testing PMID:23989453

  14. Developmental Outcome of Childhood Leukemia.

    ERIC Educational Resources Information Center

    Coniglio, Susan J.; Blackman, James A.

    1995-01-01

    Literature on developmental and psychosocial outcomes of childhood leukemia is reviewed, focusing on preschool-age children. Studies are categorized in terms of outcome measures: intelligence/achievement, neuropsychological, memory/attention, and psychosocial tests. Evidence suggests that preschool children with leukemia are at high risk for…

  15. Developmental Outcome of Childhood Leukemia.

    ERIC Educational Resources Information Center

    Coniglio, Susan J.; Blackman, James A.

    1995-01-01

    Literature on developmental and psychosocial outcomes of childhood leukemia is reviewed, focusing on preschool-age children. Studies are categorized in terms of outcome measures: intelligence/achievement, neuropsychological, memory/attention, and psychosocial tests. Evidence suggests that preschool children with leukemia are at high risk for…

  16. Obinutuzumab in chronic lymphocytic leukemia.

    PubMed

    Dupuis, Jehan

    2015-09-01

    Obinutuzumab is the second next-generation monoclonal anti-CD20 antibody (after ofatumumab) to enter clinical practice in chronic lymphocytic leukemia. Its superiority in association with chlorambucil as compared with chlorambucil alone has led to its approval as a first-line treatment for chronic lymphocytic leukemia, for patients who are not candidates for a more intensive treatment.

  17. High Throughput Drug Sensitivity Assay and Genomics- Guided Treatment of Patients With Relapsed or Refractory Acute Leukemia

    ClinicalTrials.gov

    2017-07-14

    Acute Leukemia of Ambiguous Lineage; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia

  18. Acute Lymphoblastic Leukemia (ALL) (For Parents)

    MedlinePlus

    ... TV, Video Games, and the Internet Acute Lymphoblastic Leukemia (ALL) KidsHealth > For Parents > Acute Lymphoblastic Leukemia (ALL) ... Treatment Coping en español Leucemia linfoblástica aguda About Leukemia Leukemia is a type of cancer that affects ...

  19. Juvenile Myelomonocytic Leukemia (JMML) (For Parents)

    MedlinePlus

    ... TV, Video Games, and the Internet Juvenile Myelomonocytic Leukemia (JMML) KidsHealth > For Parents > Juvenile Myelomonocytic Leukemia (JMML) ... Treatment Coping en español Leucemia mielomonocítica juvenil About Leukemia Leukemia is a type of cancer that affects ...

  20. Chronic Myelogenous Leukemia (CML) (For Parents)

    MedlinePlus

    ... TV, Video Games, and the Internet Chronic Myelogenous Leukemia (CML) KidsHealth > For Parents > Chronic Myelogenous Leukemia (CML) ... Treatment Coping en español Leucemia mielógena crónica About Leukemia Leukemia is a type of cancer that affects ...

  1. Leukemia: Recent advances in biology and treatment

    SciTech Connect

    Gale, R.P.; Golde, D.W.

    1985-01-01

    This book is a compilation of papers presented at a Symposium on the advances in the biology and treatment of leukemia. Topics covered include oncogenes and chromosomes in leukemia - the interactions of oncogenes with hemopoietic cells;the involvement of oncogenes in chronic myelogenous leukemia;oncogene regulation during erythroid differentiation;genomic rearrangements in human cancer;and pathenogenesis of leukemia.

  2. Rebeccamycin Analog in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia, Myelodysplastic Syndrome, Acute Lymphoblastic Leukemia, or Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2013-01-22

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes

  3. SJG-136 in Treating Patients With Relapsed or Refractory Acute Leukemia, Myelodysplastic Syndromes, Blastic Phase Chronic Myelogenous Leukemia, or Chronic Lymphocytic Leukemia

    ClinicalTrials.gov

    2013-09-27

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Blastic Phase Chronic Myelogenous Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Chronic Lymphocytic Leukemia; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes

  4. Bendamustine Plus Alemtuzumab for Refractory Chronic Lymphocytic Leukemia (CLL)

    ClinicalTrials.gov

    2013-08-20

    Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Stage III Chronic Lymphocytic Leukemia; Stage III Small Lymphocytic Lymphoma; Stage IV Chronic Lymphocytic Leukemia; Stage IV Small Lymphocytic Lymphoma

  5. [Molecular targeted therapy in lymphoid leukemias].

    PubMed

    Kojima, Kensuke; Ando, Toshihiko; Kimura, Shinya

    2014-06-01

    Recent advances in the treatment of lymphoid leukemias have incorporated molecular targeted drugs (CD20-targeting rituximab and BCR-ABL tyrosine kinase inhibitors) into the traditional chemotherapeutic agents. This article reviews novel molecular targeted therapies for patients with lymphoid leukemias including acute lymphoblastic leukemia, chronic lymphocytic leukemia, hairly cell leukemia and HTLV-I-related adult T-cell leukemia. Investigational agents that will be discussed in this review include inotuzumab, blinatumomab, alemtuzumab, ofatumumab, ibrutinib, idelalisib, bafetinib, lenalidomide, ABT-199 and mogamulizumab. Novel approaches warrant continued research to improve outcomes for patients with lymphoid leukemias.

  6. Donor Umbilical Cord Blood Transplant With or Without Ex-vivo Expanded Cord Blood Progenitor Cells in Treating Patients With Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Chronic Myelogenous Leukemia, or Myelodysplastic Syndromes

    ClinicalTrials.gov

    2017-09-14

    Acute Biphenotypic Leukemia; Acute Erythroid Leukemia; Acute Lymphoblastic Leukemia in Remission; Acute Megakaryoblastic Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia in Remission; Blasts Under 10 Percent of Bone Marrow Nucleated Cells; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Mixed Phenotype Acute Leukemia; Myelodysplastic Syndrome; Myelodysplastic Syndrome With Excess Blasts; Pancytopenia; Refractory Anemia; Secondary Acute Myeloid Leukemia

  7. Adult Acute Lymphoblastic Leukemia

    PubMed Central

    Faderl, Stefan; O’Brien, Susan; Pui, Ching-Hon; Stock, Wendy; Wetzler, Meir; Hoelzer, Dieter; Kantarjian, Hagop M.

    2016-01-01

    Acute lymphoblastic leukemia (ALL), a clonal expansion of hematopoietic blasts, is a highly heterogeneous disease comprising many entities for which distinct treatment strategies are pursued. Although ALL is a success story in pediatric oncology, results in adults lag behind those in children. An expansion of new drugs, more reliable immunologic and molecular techniques for the assessment of minimal residual disease, and efforts at more precise risk stratification are generating new aspects of adult ALL therapy. For this review, the authors summarized pertinent and recent literature on ALL biology and therapy, and they discuss current strategies and potential implications of novel approaches to the management of adult ALL. PMID:20101737

  8. Establishment of a myeloid leukemia cell line, TRL-01, with MLL-ENL fusion gene.

    PubMed

    Ninomiya, Manabu; Abe, Akihiro; Yokozawa, Toshiya; Ozeki, Kazutaka; Yamamoto, Kazuhito; Ito, Mamoru; Ito, Masafumi; Kiyoi, Hitoshi; Emi, Nobuhiko; Naoe, Tomoki

    2006-08-01

    We established a leukemia cell line derived from therapy-related acute myeloid leukemia with the t(11;19) by xenotransplantation into the NOD/SCID mouse with IL-2Rgamma(c)-/- (NOG mouse). The cell line, TRL-01, could be serially transplanted from mouse to mouse and also grown in an adherence-dependent manner on a murine bone marrow stroma cell line, HESS-5. TRL-01 had the same immunophenotype as the original leukemia cells: positive for CD13, CD33, CD11a, CD18, CD29, CD49d, CD49e, CD54, CD62L, and CD117, and negative for CD3, CD4, CD8, CD19, CD34, CD41a, CD41b, CD135, and myeloperoxidase. Translocation (11;19)(q23;p13) in both the original sample and TRL-01 generated MLL-ENL chimeric transcripts joining exon 6 and exon 4, respectively, which has a novel isoform. In cultures of TRL-01, addition of GM-CSF, SCF, and G-CSF and adhesion to fibronectin-coated plates promoted transient proliferation and survival, although they did not support long-term culture. Subcutaneous injection caused a tumor to form only when HESS-5 was coinjected at the same site. These results suggest that TRL-01 is a useful cell line for studying not only the leukemia-related biology of MLL-ENL but also the intercellular association between leukemia and stroma.

  9. Therapeutic Targeting of MLL Degradation Pathways in MLL-Rearranged Leukemia.

    PubMed

    Liang, Kaiwei; Volk, Andrew G; Haug, Jeffrey S; Marshall, Stacy A; Woodfin, Ashley R; Bartom, Elizabeth T; Gilmore, Joshua M; Florens, Laurence; Washburn, Michael P; Sullivan, Kelly D; Espinosa, Joaquin M; Cannova, Joseph; Zhang, Jiwang; Smith, Edwin R; Crispino, John D; Shilatifard, Ali

    2017-01-12

    Chromosomal translocations of the mixed-lineage leukemia (MLL) gene with various partner genes result in aggressive leukemia with dismal outcomes. Despite similar expression at the mRNA level from the wild-type and chimeric MLL alleles, the chimeric protein is more stable. We report that UBE2O functions in regulating the stability of wild-type MLL in response to interleukin-1 signaling. Targeting wild-type MLL degradation impedes MLL leukemia cell proliferation, and it downregulates a specific group of target genes of the MLL chimeras and their oncogenic cofactor, the super elongation complex. Pharmacologically inhibiting this pathway substantially delays progression, and it improves survival of murine leukemia through stabilizing wild-type MLL protein, which displaces the MLL chimera from some of its target genes and, therefore, relieves the cellular oncogenic addiction to MLL chimeras. Stabilization of MLL provides us with a paradigm in the development of therapies for aggressive MLL leukemia and perhaps for other cancers caused by translocations. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Eltrombopag inhibits the proliferation of leukemia cells via reduction of intracellular iron and induction of differentiation.

    PubMed

    Roth, Michael; Will, Britta; Simkin, Guillermo; Narayanagari, Swathi; Barreyro, Laura; Bartholdy, Boris; Tamari, Roni; Mitsiades, Constantine S; Verma, Amit; Steidl, Ulrich

    2012-07-12

    Eltrombopag (EP) is a small-molecule, nonpeptide thrombopoietin receptor (TPO-R) agonist that has been approved recently for the treatment of thrombocytopenia in patients with chronic immune thrombocytopenic purpura. Prior studies have shown that EP stimulates megakaryopoiesis in BM cells from patients with acute myeloid leukemia and myelodysplastic syndrome, and the results also suggested that it may inhibit leukemia cell growth. In the present study, we studied the effects of EP on leukemia cell proliferation and the mechanism of its antiproliferative effects. We found that EP leads to a decreased cell division rate, a block in G(1) phase of cell cycle, and increased differentiation in human and murine leukemia cells. Because EP is species specific in that it can only bind TPO-R in human and primate cells, these findings further suggested that the antileukemic effect is independent of TPO-R. We found that treatment with EP leads to a reduction in free intracellular iron in leukemic cells in a dose-dependent manner. Experimental increase of intracellular iron abrogated the antiproliferative and differentiation-inducing effects of EP, demonstrating that its antileukemic effects are mediated through modulation of intracellular iron content. Finally, determination of EP's antileukemic activity in vivo demonstrated its ability to prolong survival in 2 mouse models of leukemia.

  11. Complementing mutations in core binding factor leukemias: from mouse models to clinical applications.

    PubMed

    Müller, A M S; Duque, J; Shizuru, J A; Lübbert, M

    2008-10-02

    A great proportion of acute myeloid leukemias (AMLs) display cytogenetic abnormalities including chromosomal aberrations and/or submicroscopic mutations. These abnormalities significantly influence the prognosis of the disease. Hence, a thorough genetic work-up is an essential constituent of standard diagnostic procedures. Core binding factor (CBF) leukemias denote AMLs with chromosomal aberrations disrupting one of the CBF transcription factor genes; the most common examples are translocation t(8;21) and inversion inv(16), which result in the generation of the AML1-ETO and CBFbeta-MYH11 fusion proteins, respectively. However, in murine models, these alterations alone do not suffice to generate full-blown leukemia, but rather, complementary events are required. In fact, a substantial proportion of primary CBF leukemias display additional activating mutations, mostly of the receptor tyrosine kinase (RTK) c-KIT. The awareness of the impact and prognostic relevance of these 'second hits' is increasing with a wider range of mutations tested in clinical trials. Furthermore, novel agents targeting RTKs are emanating rapidly and entering therapeutic regimens. Here, we present a concise review on complementing mutations in CBF leukemias including pathophysiology, mouse models, and clinical implications.

  12. Specificity of disease induced by M-MuLV chimeric retroviruses containing v-myc or v-src is not determined by the LTR.

    PubMed

    Feuer, G; Lee, W T; Pattengale, P K; Fan, H

    1993-07-01

    The long terminal repeats (LTRs) of defective Moloney Murine Leukemia Virus (M-MuLV) containing the avian v-myc and v-src oncogenes were exchanged for LTRs from murine retroviruses inducing myeloid and erythroid disease, in an attempt to retarget disease specificity. Chimeric MuLVs containing either the Myeloproliferative sarcoma virus or the Rauscher mink cell focus-inducing virus LTRs induced the same disease as the parental viruses, suggesting that for these viruses the v-myc and v-src oncogenes are the major determinants in the disease specificity. However, substitution of the LTRs did affect the efficiency of tumorigenesis.

  13. Immunity to WT1 in the animal model and in patients with acute myeloid leukemia.

    PubMed

    Gaiger, A; Reese, V; Disis, M L; Cheever, M A

    2000-08-15

    The Wilms' tumor (WT1) gene participates in leukemogenesis and is overexpressed in most types of leukemia in humans. WT1 is also detectable in many types of lung, thyroid, breast, testicular, and ovarian cancers and melanoma in humans. Initial studies evaluated whether immune responses to murine WT1 can be elicited in mice. Murine and human WT1 are similar. Thus, mouse models might lead to resolution of many of the critical issues for developing WT1 vaccines. C57/BL6 (B6) mice were injected with synthetic peptides from the natural sequence of WT1 containing motifs for binding to major histocompatibility (MHC) class II molecules. Immunization induced helper T-cell responses specific for the immunizing WT1 peptides and antibody responses specific for WT1 protein. Screening of multiple murine cancer cell lines identified 2 murine cancers, TRAMP-C and BLKSV40, that "naturally" overexpress WT1. Immunization with MHC class I binding peptides induced WT1 peptide-specific cytotoxic T-lymphocyte (CTL) that specifically lysed TRAMP-C and BLKSV40. WT1 specificity of lysis was confirmed by cold target inhibition. No toxicity was noted by histopathologic evaluation in the WT1 peptide-immunized animals. WT1 peptide immunization did not show any effect on TRAMP-C tumor growth in vivo. Immunization of B6 mice to syngeneic TRAMP-C elicited WT1-specific antibody, demonstrating that WT1 can be immunogenic in the context of cancer cells. To evaluate whether WT1 might be similarly immunogenic in humans, serum from patients with leukemia was evaluated for pre-existing antibody responses. Western blot analyses showed WT1-specific antibodies directed against the N-terminus portion of the WT1 protein in the sera of 3 of 18 patients with acute myeloid leukemia (AML). (Blood. 2000;96:1480-1489)

  14. Tipifarnib in Treating Patients With Chronic Myeloid Leukemia, Chronic Myelomonocytic Leukemia, or Undifferentiated Myeloproliferative Disorders

    ClinicalTrials.gov

    2017-05-08

    Accelerated Phase of Disease; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Myelomonocytic Leukemia; Chronic Phase of Disease; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Recurrent Disease

  15. The allometry of chronic myeloid leukemia.

    PubMed

    Pacheco, Jorge M; Traulsen, Arne; Dingli, David

    2009-08-07

    Chronic myeloid leukemia (CML) is an acquired neoplastic hematopoietic stem cell (HSC) disorder characterized by the expression of the BCR-ABL oncoprotein. This gene product is necessary and sufficient to explain the chronic phase of CML. The only known cause of CML is radiation exposure leading to a mutation of at least one HSC, although the vast majority of patients with CML do not have a history of radiation exposure. Nonetheless, in humans, significant radiation exposure (after exposure to atomic bomb fallout) leads to disease diagnosis in 3-5 years. In murine models, disease dynamics are much faster and CML is fatal over the span of a few months. Our objective is to develop a model that accounts for CML across all mammals. In the following, we combine a model of CML dynamics in humans with allometric scaling of hematopoiesis across mammals to illustrate the natural history of chronic phase CML in various mammals. We show how a single cell can lead to a fatal illness in mice and humans but a higher burden of CML stem cells is necessary to induce disease in larger mammals such as elephants. The different dynamics of the disease is rationalized in terms of mammalian mass. Our work illustrates the relevance of animal models to understand human disease and highlights the importance of considering the re-scaling of the dynamics that accrues to the same biological process when planning experiments involving different species.

  16. ZFP521 regulates murine hematopoietic stem cell function and facilitates MLL-AF9 leukemogenesis in mouse and human cells.

    PubMed

    Garrison, Brian S; Rybak, Adrian P; Beerman, Isabel; Heesters, Balthasar; Mercier, Francois E; Scadden, David T; Bryder, David; Baron, Roland; Rossi, Derrick J

    2017-08-03

    The concept that tumor-initiating cells can co-opt the self-renewal program of endogenous stem cells as a means of enforcing their unlimited proliferative potential is widely accepted, yet identification of specific factors that regulate self-renewal of normal and cancer stem cells remains limited. Using a comparative transcriptomic approach, we identify ZNF521/Zfp521 as a conserved hematopoietic stem cell (HSC)-enriched transcription factor in human and murine hematopoiesis whose function in HSC biology remains elusive. Competitive serial transplantation assays using Zfp521-deficient mice revealed that ZFP521 regulates HSC self-renewal and differentiation. In contrast, ectopic expression of ZFP521 in HSCs led to a robust maintenance of progenitor activity in vitro. Transcriptional analysis of human acute myeloid leukemia (AML) patient samples revealed that ZNF521 is highly and specifically upregulated in AMLs with MLL translocations. Using an MLL-AF9 murine leukemia model and serial transplantation studies, we show that ZFP521 is not required for leukemogenesis, although its absence leads to a significant delay in leukemia onset. Furthermore, knockdown of ZNF521 reduced proliferation in human leukemia cell lines possessing MLL-AF9 translocations. Taken together, these results identify ZNF521/ZFP521 as a critical regulator of HSC function, which facilitates MLL-AF9-mediated leukemic disease in mice.

  17. Leukemia: genetics and prognostic factors.

    PubMed

    Hamerschlak, Nelson

    2008-08-01

    To present the implications of genetics, particularly of cytogenetic techniques, for the diagnosis and prognosis of leukemia. A survey of articles selected from MEDLINE, American Society of Hematology educational programs, the CAPES web portal, the National Comprehensive Cancer Network and textbook chapters. Since the discovery in 1960 by Peter C. Nowel and David Hungerford of the 9:22 translocation (the Philadelphia chromosome), genetics has come to play an important role in hematology, in this case making it possible to diagnose chronic myeloid leukemia and opening doors to research avenues for the whole field of oncology. One point of great interest refers to the implications of these findings for the prognosis of a range of types of leukemia. In acute myeloid leukemia, the karyotype is of fundamental importance to postremission treatment decisions, and molecular factors determine the treatment of individuals with normal karyotypes. In chronic myeloid leukemia, clonal evolution is associated with progression to the blast crisis. Patients on imatinib who cease responding may have mutations on their ABL gene. Finally, in acute lymphoblastic leukemia, factors such as hyperdiploidy and t 12:21 are associated with good prognosis, whereas carriers of t 4:11 and t 9:22 are considered high risk patients. Genetics has come to stay as far as hematology and, in particular, the management of leukemia and its prognostic factors are concerned. These tests should always be carried out and the appropriate treatment adopted in the light of their results, so that optimal patient outcomes can be achieved.

  18. Entinostat and Clofarabine in Treating Patients With Newly Diagnosed, Relapsed, or Refractory Poor-Risk Acute Lymphoblastic Leukemia or Bilineage/Biphenotypic Leukemia

    ClinicalTrials.gov

    2014-07-16

    Acute Leukemias of Ambiguous Lineage; Philadelphia Chromosome Negative Adult Precursor Acute Lymphoblastic Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia

  19. Marrow transplantation for leukemia

    SciTech Connect

    Thomas, E.D.

    1981-07-01

    Marrow transplantation for selected patients with leukemia, as for patients with severe combined immunologic deficiency or severe aplastic anemia, has now become an accepted clinical procedure. For patients with acute leukemia who have relapsed after achieving a remission of chemotherapy, marrow grafting from an identical twin or an HLA-identical sibling has now been demonstrated to produce median remissions as long as or longer than any reported for combination chemotherapy. In contrast to chemotherapy, marrow transplantation offers the possibility of cure for a small but significant fraction of these patients. Marrow transplantation for patients with ANL in first remission has now resulted in median survivals much longer than any reported with chemotherapy. Although it now appears that more than 50% of these patients can be cured with marrow transplantation, a much longer follow-up is indicated since some patients who achieve a complete remission with combination chemotherapy are now living for a long time, and some of these patients (less than 20%) may also be cured. Current intensive research with new modalities such as interferon, Acyclovir, Cyclosporin A, and monoclonal antibodies can reasonably be expected to improve the overall results of marrow transplantation.

  20. MicroRNA profiling can classify acute leukemias of ambiguous lineage as either acute myeloid leukemia or acute lymphoid leukemia.

    PubMed

    de Leeuw, David C; van den Ancker, Willemijn; Denkers, Fedor; de Menezes, Renée X; Westers, Theresia M; Ossenkoppele, Gert J; van de Loosdrecht, Arjan A; Smit, Linda

    2013-04-15

    Classification of acute leukemia is based on the commitment of leukemic cells to the myeloid or the lymphoid lineage. However, a small percentage of acute leukemia cases lack straightforward immunophenotypical lineage commitment. These leukemias of ambiguous lineage represent a heterogeneous category of acute leukemia that cannot be classified as either acute myeloid leukemia (AML) or acute lymphoid leukemia (ALL). The lack of clear classification of acute leukemias of ambiguous lineage as either AML or ALL is a hurdle in treatment choice for these patients. Here, we compared the microRNA (miRNA) expression profiles of 17 cases with acute leukemia of ambiguous lineage and 16 cases of AML, B-cell acute lymphoid leukemia (B-ALL), and T-cell acute lymphoid leukemia (T-ALL). We show that leukemias of ambiguous lineage do not segregate as a separate entity but exhibit miRNA expression profiles similar to AML, B-ALL, or T-ALL. We show that by using only 5 of the most lineage-discriminative miRNAs, we are able to define acute leukemia of ambiguous lineage as either AML or ALL. Our results indicate the presence of a myeloid or lymphoid lineage-specific genotype, as reflected by miRNA expression, in these acute leukemias despite their ambiguous immunophenotype. miRNA-based classification of acute leukemia of ambiguous lineage might be of additional value in therapeutic decision making.

  1. Lenalidomide in Treating Older Patients With Acute Myeloid Leukemia

    ClinicalTrials.gov

    2014-07-25

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

  2. What Should You Ask Your Doctor about Acute Lymphocytic Leukemia?

    MedlinePlus

    ... Types What Should You Ask Your Doctor About Acute Lymphocytic Leukemia? It is important to have frank, honest discussions ... Your Doctor About Acute Lymphocytic Leukemia? More In Acute Lymphocytic Leukemia About Acute Lymphocytic Leukemia Causes, Risk Factors, and ...

  3. What Should You Ask Your Doctor about Chronic Lymphocytic Leukemia?

    MedlinePlus

    ... Should You Ask Your Doctor About Chronic Lymphocytic Leukemia? As you cope with cancer and cancer treatment, ... About Chronic Lymphocytic Leukemia? More In Chronic Lymphocytic Leukemia About Chronic Lymphocytic Leukemia Causes, Risk Factors, and ...

  4. What Should You Ask Your Doctor about Chronic Myeloid Leukemia?

    MedlinePlus

    ... Should You Ask Your Doctor About Chronic Myeloid Leukemia? As you cope with cancer and cancer treatment, ... About Chronic Myeloid Leukemia? More In Chronic Myeloid Leukemia About Chronic Myeloid Leukemia Causes, Risk Factors, and ...

  5. What Are the Risk Factors for Chronic Myeloid Leukemia?

    MedlinePlus

    ... What Are the Risk Factors for Chronic Myeloid Leukemia? A risk factor is something that affects a ... Myeloid Leukemia Be Prevented? More In Chronic Myeloid Leukemia About Chronic Myeloid Leukemia Causes, Risk Factors, and ...

  6. What's New in Chronic Lymphocytic Leukemia Research and Treatment?

    MedlinePlus

    ... Lymphocytic Leukemia (CLL) About Chronic Lymphocytic Leukemia What's New in Chronic Lymphocytic Leukemia Research and Treatment? Many ... person's outlook and whether they will need treatment. New drugs for chronic lymphocytic leukemia Dozens of new ...

  7. Modulating Leukemia-Initiating Cell Quiescence to Improve Leukemia Treatment

    DTIC Science & Technology

    2015-09-01

    chromosome translocation. We utilized a mouse model of human acute myeloid leukemia (AML) induced by the MLL-AF9 oncogene to determine the role of Necdin...function as an endogenous anti-mitotic and anti-apoptotic protein in post-mitotic neurons [1]. The necdin gene is located on chromosome 15 in human and...Downing, J.R. (1996). AML1, the target of multiple chromosomal translocations in human leukemia, is essential for normal fetal liver hematopoiesis. Cell

  8. CCI-779 in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Myelodysplastic Syndromes, or Chronic Myelogenous Leukemia in Blastic Phase

    ClinicalTrials.gov

    2013-01-22

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia; Secondary Myelodysplastic Syndromes

  9. Cilengitide in Treating Patients With Acute Myeloid Leukemia

    ClinicalTrials.gov

    2013-01-23

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b)

  10. Murine typhus in travelers returning from Indonesia.

    PubMed Central

    Parola, P.; Vogelaers, D.; Roure, C.; Janbon, F.; Raoult, D.

    1998-01-01

    We report the first three documented cases of murine typhus imported into Europe from Indonesia, discuss clues for the diagnosis of the disease, and urge that murine fever be considered in the diagnosis of febrile disease in travelers. PMID:9866749

  11. Murine typhus in travelers returning from Indonesia.

    PubMed

    Parola, P; Vogelaers, D; Roure, C; Janbon, F; Raoult, D

    1998-01-01

    We report the first three documented cases of murine typhus imported into Europe from Indonesia, discuss clues for the diagnosis of the disease, and urge that murine fever be considered in the diagnosis of febrile disease in travelers.

  12. Decitabine in Treating Patients With Previously Untreated Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-05-18

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

  13. Murine Gammaretrovirus Group G3 Was Not Found in Swedish Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia

    PubMed Central

    Elfaitouri, Amal; Mattsson Ulfstedt, Johan; Muradrasoli, Shaman; Bölin Wiener, Agnes; Golbob, Sultan; Öhrmalm, Christina; Matousek, Michael; Zachrisson, Olof; Gottfries, Carl-Gerhard; Blomberg, Jonas

    2011-01-01

    Background The recent report of gammaretroviruses of probable murine origin in humans, called xenotropic murine retrovirus related virus (XMRV) and human murine leukemia virus related virus (HMRV), necessitated a bioinformatic search for this virus in genomes of the mouse and other vertebrates, and by PCR in humans. Results Three major groups of murine endogenous gammaretroviruses were identified. The third group encompassed both exogenous and endogenous Murine Leukemia Viruses (MLVs), and most XMRV/HMRV sequences reported from patients suffering from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Two sensitive real-time PCRs for this group were developed. The predicted and observed amplification range for these and three published XMRV/HMRV PCRs demonstrated conspicuous differences between some of them, partly explainable by a recombinatorial origin of XMRV. Three reverse transcription real-time PCRs (RTQPCRs), directed against conserved and not overlapping stretches of env, gag and integrase (INT) sequences of XMRV/HMRV were used on human samples. White blood cells from 78 patients suffering from ME/CFS, of which 30 patients also fulfilled the diagnostic criteria for fibromyalgia (ME/CFS/FM) and in 7 patients with fibromyalgia (FM) only, all from the Gothenburg area of Sweden. As controls we analyzed 168 sera from Uppsala blood donors. We controlled for presence and amplifiability of nucleic acid and for mouse DNA contamination. To score as positive, a sample had to react with several of the XMRV/HMRV PCRs. None of the samples gave PCR reactions which fulfilled the positivity criteria. Conclusions XMRV/HMRV like proviruses occur in the third murine gammaretrovirus group, characterized here. PCRs developed by us, and others, approximately cover this group, except for the INT RTQPCR, which is rather strictly XMRV specific. Using such PCRs, XMRV/HMRV could not be detected in PBMC and plasma samples from Swedish patients suffering from ME/CFS/FM, and in

  14. Vaccine Therapy Plus Immune Adjuvant in Treating Patients With Chronic Myeloid Leukemia, Acute Myeloid Leukemia, or Myelodysplastic Syndrome

    ClinicalTrials.gov

    2013-01-04

    Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Myeloid Leukemia in Remission; Chronic Phase Chronic Myelogenous Leukemia; Previously Treated Myelodysplastic Syndromes; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia

  15. How Is Childhood Leukemia Classified?

    MedlinePlus

    ... Classification based on how the leukemia cells look (morphology) In the past, doctors used the French-American- ... of AML are classified mainly based on their morphology (how they look under the microscope). There are ...

  16. Pharmacogenetics in Acute Lymphoblastic Leukemia

    PubMed Central

    Cheok, Meyling H.; Pottier, Nicolas; Kager, Leo

    2009-01-01

    Progress in the treatment of acute leukemia in children has been remarkable, from a disease being lethal four decades ago to current cure rates exceeding 80%. This exemplary progress is largely due to the optimization of existing treatment modalities rather than the discovery of new antileukemic agents. However, despite these high cure rates, the annual number of children whose leukemia relapses after their initial therapy remains greater than that of new cases of most types of childhood cancers. The aim of pharmacogenetics is to develop strategies to personalize treatment and tailor therapy to individual patients, with the goal of optimizing efficacy and safety through better understanding of human genome variability and its influence on drug response. In this review, we summarize recent pharmacogenomic studies related to the treatment of pediatric acute lymphoblastic leukemia. These studies illustrate the promise of pharmacogenomics to further advance the treatment of human cancers, with childhood leukemia serving as a paradigm. PMID:19100367

  17. Down syndrome preleukemia and leukemia.

    PubMed

    Maloney, Kelly W; Taub, Jeffrey W; Ravindranath, Yaddanapudi; Roberts, Irene; Vyas, Paresh

    2015-02-01

    Children with Down syndrome (DS) and acute leukemias acute have unique biological, cytogenetic, and intrinsic factors that affect their treatment and outcome. Myeloid leukemia of Down syndrome (ML-DS) is associated with high event-free survival (EFS) rates and frequently preceded by a preleukemia condition, the transient abnormal hematopoiesis (TAM) present at birth. For acute lymphoblastic leukemia (ALL), their EFS and overall survival are poorer than non-DS ALL, it is important to enroll them on therapeutic trials, including relapse trials; investigate new agents that could potentially improve their leukemia-free survival; and strive to maximize the supportive care these patients need. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Isolated Hoxa9 overexpression predisposes to the development of lymphoid but not myeloid leukemia.

    PubMed

    Beachy, Sarah H; Onozawa, Masahiro; Silverman, Deborah; Chung, Yang Jo; Rivera, Mariela Martinez; Aplan, Peter D

    2013-06-01

    Hoxa9 is expressed in hematopoietic stem and progenitor cells, although this expression is usually diminished as these cells undergo differentiation. In addition, aberrant expression of Hoxa9 is strongly associated with both T cell and myeloid leukemia in mice and humans. Despite this strong association, enforced expression of Hoxa9 in murine bone marrow or thymus has only shown a modest ability to transform cells. To investigate this question, we used Vav regulatory elements to generate a transgenic mouse that targets Hoxa9 overexpression to all hematopoietic tissues. High-level expression of the Hoxa9 transgene in the hematopoietic compartment was associated with embryonic lethality, as no pups from founders that expressed high levels of the transgene were born live. However, offspring of an additional founder line, which expressed lower levels of Hoxa9, developed a precursor T cell lymphoblastic leukemia/lymphoma, accompanied by spontaneous Notch1 mutations. In contrast to most murine models of leukemia associated with Hoxa9 overexpression, the Vav-Hoxa9 mice did not overexpress other Hoxa cluster genes, mir196b (a microRNA that is embedded in the Hoxa locus), Meis1, or Pbx3. The Hoxa9 transgenic mouse reported in this study provides a suitable system for the study of Hoxa9 collaborators that drive myeloid and lymphoid malignant transformation.

  19. PROGRESS IN ACUTE MYELOID LEUKEMIA

    PubMed Central

    Kadia, Tapan M.; Ravandi, Farhad; O’Brien, Susan; Cortes, Jorge; Kantarjian, Hagop M.

    2014-01-01

    Significant progress has been made in the treatment of acute myeloid leukemia (AML). Steady gains in clinical research and a renaissance of genomics in leukemia have led to improved outcomes. The recognition of tremendous heterogeneity in AML has allowed individualized treatments of specific disease entities within the context of patient age, cytogenetics, and mutational analysis. The following is a comprehensive review of the current state of AML therapy and a roadmap of our approach to these distinct disease entities. PMID:25441110

  20. Treatment of prolymphocytic leukemia

    SciTech Connect

    Hollister, S. Jr.; Coleman, M.

    1982-11-01

    Prolymphocytic leukemia is characterized by marked splenomegaly, distinctive cellular morphologic characteristics, and a poor clinical course. Five patients with typical PL were treated systematically with vincristine/prednisone, chlorambucil/prednisone, splenic irradiation, splenectomy, and other chemotherapy regimens. No patient responded to vincristine/prednisone. Two patients responded to chlorambucil/prednisone, and four patients had brief responses to splenic irradiation. Two patients underwent splenectomy, one of whom had a prolonged clinical remissions. No other chemotherapy combinations were of value. The median survival was 33 months. Recommendations are made to use chlorambucil/prednisone or splenic irradiation as initial treatment. Splenectomy should be considered in patients refractory to these modalities. The course of PL may be more protracted than originally reported.

  1. Risk-Based Classification System of Patients With Newly Diagnosed Acute Lymphoblastic Leukemia

    ClinicalTrials.gov

    2017-02-13

    Adult B Acute Lymphoblastic Leukemia; Adult T Acute Lymphoblastic Leukemia; Childhood B Acute Lymphoblastic Leukemia; Childhood T Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

  2. Induction of Protective CTL Responses in Newborn Mice by a Murine Retrovirus

    NASA Astrophysics Data System (ADS)

    Sarzotti, Marcella; Robbins, Deanna S.; Hoffman, Paul M.

    1996-03-01

    The susceptibility of neonates to virus-induced disease is thought to reflect, in part, the immaturity of their immune systems. However, inoculation of newborn mice with low doses of Cas-Br-M murine leukemia virus induced a protective cytotoxic T lymphocyte (CTL) response. The inability of neonates to develop a CTL response to high doses of virus was not the result of immunological immaturity but correlated with the induction of a nonprotective type 2 cytokine response. Thus, the initial viral dose is critical in the development of protective immunity in newborns.

  3. Antibody Therapy for Pediatric Leukemia

    PubMed Central

    Vedi, Aditi; Ziegler, David S.

    2014-01-01

    Despite increasing cure rates for pediatric leukemia, relapsed disease still carries a poor prognosis with significant morbidity and mortality. Novel targeted therapies are currently being investigated in an attempt to reduce adverse events and improve survival outcomes. Antibody therapies represent a form of targeted therapy that offers a new treatment paradigm. Monoclonal antibodies are active in pediatric acute lymphoblastic leukemia (ALL) and are currently in Phase III trials. Antibody-drug conjugates (ADCs) are the next generation of antibodies where a highly potent cytotoxic agent is bound to an antibody by a linker, resulting in selective targeting of leukemia cells. ADCs are currently being tested in clinical trials for pediatric acute myeloid leukemia and ALL. Bispecific T cell engager (BiTE) antibodies are a construct whereby each antibody contains two binding sites, with one designed to engage the patient’s own immune system and the other to target malignant cells. BiTE antibodies show great promise as a novel and effective therapy for childhood leukemia. This review will outline recent developments in targeted agents for pediatric leukemia including monoclonal antibodies, ADCs, and BiTE antibodies. PMID:24795859

  4. The MN1-TEL fusion protein, encoded by the translocation (12;22)(p13;q11) in myeloid leukemia, is a transcription factor with transforming activity.

    PubMed

    Buijs, A; van Rompaey, L; Molijn, A C; Davis, J N; Vertegaal, A C; Potter, M D; Adams, C; van Baal, S; Zwarthoff, E C; Roussel, M F; Grosveld, G C

    2000-12-01

    The Tel gene (or ETV6) is the target of the translocation (12;22)(p13;q11) in myeloid leukemia. TEL is a member of the ETS family of transcription factors and contains the pointed protein interaction (PNT) domain and an ETS DNA binding domain (DBD). By contrast to other chimeric proteins that contain TEL's PNT domain, such as TEL-platelet-derived growth factor beta receptor in t(5;12)(q33;p13), MN1-TEL contains the DBD of TEL. The N-terminal MN1 moiety is rich in proline residues and contains two polyglutamine stretches, suggesting that MN1-TEL may act as a deregulated transcription factor. We now show that MN1-TEL type I, unlike TEL and MN1, transforms NIH 3T3 cells. The transforming potential depends on both N-terminal MN1 sequences and a functional TEL DBD. Furthermore, we demonstrate that MN1 has transcription activity and that MN1-TEL acts as a chimeric transcription factor on the Moloney sarcoma virus long terminal repeat and a synthetic promoter containing TEL binding sites. The transactivating capacity of MN1-TEL depended on both the DBD of TEL and sequences in MN1. MN1-TEL contributes to leukemogenesis by a mechanism distinct from that of other chimeric proteins containing TEL.

  5. Tipifarnib in Treating Older Patients With Acute Myeloid Leukemia

    ClinicalTrials.gov

    2015-03-19

    Adult Acute Megakaryoblastic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With Minimal Differentiation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

  6. Suppression of retroviral propagation and disease by suramin in murine systems.

    PubMed Central

    Ruprecht, R M; Rossoni, L D; Haseltine, W A; Broder, S

    1985-01-01

    Retroviral propagation crucially depends on reverse transcriptase (RT). We have developed murine models to test the biological effectiveness of the RT inhibitor suramin. The drug was active in our assay system, which includes (i) inhibition of RT activity in the murine T-cell tropic virus SL3-3 and Rauscher murine leukemia virus (MuLV), (ii) inhibition of plaque formation in the XC plaque assay, (iii) inhibition of viral infection of cultured murine T cells, and (iv) inhibition of splenomegaly induced by Rauscher MuLV in BALB/c mice. Suramin decreases viral titers significantly, even if started 36 hr after infection. Viral titers and number of infected cells increased to control levels after removal of the drug. BALB/c mice treated i.v. with 40 mg of suramin per kg twice per week following infection with Rauscher MuLV showed a 35% decrease in splenomegaly. Suramin is an active antiretroviral agent whose effect on retroviral propagation is reversible. We conclude that it acts as a virustatic drug and that long-term administration of suramin will be necessary if it is used for experimental treatment of human retroviral illnesses such as the acquired immune deficiency syndrome. PMID:2415971

  7. Antimicrobial proteins of murine macrophages.

    PubMed Central

    Hiemstra, P S; Eisenhauer, P B; Harwig, S S; van den Barselaar, M T; van Furth, R; Lehrer, R I

    1993-01-01

    Three murine microbicidal proteins (MUMPs) were purified from cells of the murine macrophage cell line RAW264.7 that had been activated by gamma interferon. Similar proteins were also present in nonactivated RAW264.7 cells, in cells of the murine macrophage cell line J774A.1, and in resident and activated murine peritoneal macrophages. MUMP-1, MUMP-2, and MUMP-3 killed Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Mycobacterium fortuitum, and Cryptococcus neoformans in vitro. MUMP-1 resembled an H1 histone but was unusual because its N-terminal residue (serine) was not N acetylated. Although MUMP-2 was N terminally blocked, its high lysine/arginine ratio and its reactivity with an antibody to H1 histones suggested that it also belonged to the H1 histone family. MUMP-3 was identical to histone H2B in 30 of 30 amino-terminal residues. Although the antimicrobial properties of histones have been recognized for decades, this is the first evidence that such proteins may endow the lysosomal apparatus of macrophages with nonoxidative antimicrobial potential. Other MUMPs, including some with a more restricted antimicrobial spectrum and one that appeared to be induced in RAW264.7 cells after gamma interferon stimulation, were noted but remain to be characterized. Images PMID:8514411

  8. Phase I/II Study of Nilotinib/Ruxolitinb Therapy for TKI Resistant Ph-Leukemia

    ClinicalTrials.gov

    2016-03-04

    Chronic Phase Chronic Myeloid Leukemia; Accelerated Phase Chronic Myeloid Leukemia; Blastic Phase Chronic Myeloid Leukemia; Philadelphia Positive Acute Lymphoblastic Leukemia; Resistant to Tyrosine Kinase Inhibitor Therapy

  9. 8-Chloro-Adenosine in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-11-08

    Recurrent Adult Acute Myeloid Leukemia; Relapsed Adult Acute Myeloid Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia Arising From Previous Myeloproliferative Disorder

  10. Leukemia cutis with lymphoglandular bodies: a clue to acute lymphoblastic leukemia cutis.

    PubMed

    Obiozor, Cynthia; Ganguly, Siddhartha; Fraga, Garth R

    2015-08-15

    Leukemia cutis describes cutaneous lesions produced by infiltrates of leukemic cells. It usually manifests contemporaneously with the initial diagnosis of systemic leukemia, but may also precede or follow systemic leukemia. Most cases are associated with acute myeloid leukemia. Adult B-cell lymphoblastic leukemia cutis is very rare. We report a 59-year-old woman with a history of B-cell acute lymphoblastic leukemia who relapsed with aleukemic lymphoblastic leukemia cutis. Lymphoglandular bodies were conspicuous on biopsy and may serve as a morphologic clue to lymphocytic differentiation while molecular and immunophenotypic studies are pending. The patient was successfully treated with local radiation therapy and oral ponatinib.

  11. ChREBP promotes the differentiation of leukemia-initiating cells to inhibit leukemogenesis through the TXNIP/RUNX1 pathways

    PubMed Central

    Zeng, Hongxiang; Gu, Hao; Chen, Chiqi; Li, Minle; Xia, Fangzhen; Xie, Li; Liu, Xiaoye; Zhang, Feifei; Tong, Xuemei; Wang, Jiangbo; Yu, Zhuo; Zheng, Junke

    2016-01-01

    Targeting leukemia-initiating cells (LICs) is the key to eradicating leukemia and preventing its relapse. Recent studies have indicated that metabolic regulation may play a critical role in the maintenance of stemness in LICs, although the detailed mechanisms are poorly understood. Herein, we provide intriguing evidence showing that a glucose-responsive transcription factor, carbohydrate responsive element binding protein (ChREBP), served as a tumor suppressor rather than an oncogene, as previously described, to inhibit the development of acute myeloid leukemia by promoting the differentiation of LICs. Using an MLL-AF9-induced murine leukemia model, we demonstrated that the deletion of ChREBP resulted in the blockage of the differentiation of LICs and significantly reduced survival in ChREBP-null leukemic mice. However, ChREBP was not required for the normal repopulation abilities of hematopoietic stem cells. ChREBP promoted leukemia cell differentiation through the direct inhibition of RUNX1 or the transactivation of TXNIP to downregulate the RUNX1 level and ROS generation. Moreover, knockdown of ChREBP in human leukemia THP1 cells led to markedly enhanced proliferation and decreased differentiation upon PMA treatment. Collectively, we unraveled an unexpected role of ChREBP in leukemogenesis, which may provide valuable clues for developing novel metabolic strategies for leukemia treatment. PMID:27224916

  12. How Is Acute Lymphocytic Leukemia Diagnosed?

    MedlinePlus

    ... Adults Early Detection, Diagnosis, and Types How Is Acute Lymphocytic Leukemia Diagnosed? Certain signs and symptoms can suggest that ... described below. Tests used to diagnose and classify ALL If your doctor thinks you have leukemia, he ...

  13. The Childhood Leukemia International Consortium

    PubMed Central

    Metayer, Catherine; Milne, Elizabeth; Clavel, Jacqueline; Infante-Rivard, Claire; Petridou, Eleni; Taylor, Malcolm; Schüz, Joachim; Spector, Logan G.; Dockerty, John D.; Magnani, Corrado; Pombo-de-Oliveira, Maria S.; Sinnett, Daniel; Murphy, Michael; Roman, Eve; Monge, Patricia; Ezzat, Sameera; Mueller, Beth A.; Scheurer, Michael E.; Armstrong, Bruce K.; Birch, Jill; Kaatsch, Peter; Koifman, Sergio; Lightfoot, Tracy; Bhatti, Parveen; Bondy, Melissa L.; Rudant, Jérémie; O’Neill, Kate; Miligi, Lucia; Dessypris, Nick; Kang, Alice Y.; Buffler, Patricia A.

    2013-01-01

    Background Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case–control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene–environment interactions. Objectives The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote investigations of rarer exposures, gene–environment interactions and subtype-specific associations through the pooling of data from independent studies. Methods By September 2012, CLIC included 22 studies (recruitment period: 1962–present) from 12 countries, totaling approximately 31 000 cases and 50 000 controls. Of these, 19 case–control studies have collected detailed epidemiologic data, and DNA samples have been collected from children and child–parent trios in 15 and 13 of these studies, respectively. Two registry-based studies and one study comprising hospital records routinely obtained at birth and/or diagnosis have limited interview data or biospecimens. Conclusions CLIC provides a unique opportunity to fill gaps in knowledge about the role of environmental and genetic risk factors, critical windows of exposure, the effects of gene–environment interactions and associations among specific leukemia subtypes in different ethnic

  14. Childhood leukemia in Woburn, Massachusetts.

    PubMed Central

    Cutler, J J; Parker, G S; Rosen, S; Prenney, B; Healey, R; Caldwell, G G

    1986-01-01

    Possible associations between environmental hazards and the occurrence of childhood leukemia were investigated in Woburn, MA, for the period 1969-79. Residents of Woburn were concerned over what they perceived to be a large number of childhood leukemia cases; at the same time there was extensive publicity about uncontrolled hazardous waste sites in Woburn, which resulted in its being placed on the Superfund list. Many believed that the elevated rate of childhood leukemia was related to these sites or to two city water wells that had been closed in 1979 when they were found to be contaminated by organic chemicals. An occurrence was defined as childhood leukemia when it was diagnosed in a Woburn resident less than 20 years old between 1969 and 1979 and confirmed by review of hospital and pathology records. This investigation confirmed an increase in incidence which was distributed uniformly over the 11-year period. Six of the persons with leukemia were located close to each other in one census tract, 7.5 times the expected number. Parents of the children and of two matched control groups were interviewed about medical history, mother's pregnancy history, school history, and environmental exposures. There were no significant differences between the leukemia victims and persons in the control groups. No leukemia sufferer had contact with a hazardous waste site. While the contaminants of Wells G and H, which had been closed, are not known leukemogens, it is not possible to rule out exposure to this water as a factor, particularly in the eastern Woburn residents. PMID:3083476

  15. SPARC promotes leukemic cell growth and predicts acute myeloid leukemia outcome

    PubMed Central

    Alachkar, Houda; Santhanam, Ramasamy; Maharry, Kati; Metzeler, Klaus H.; Huang, Xiaomeng; Kohlschmidt, Jessica; Mendler, Jason H.; Benito, Juliana M.; Hickey, Christopher; Neviani, Paolo; Dorrance, Adrienne M.; Anghelina, Mirela; Khalife, Jihane; Tarighat, Somayeh S.; Volinia, Stefano; Whitman, Susan P.; Paschka, Peter; Hoellerbauer, Pia; Wu, Yue-Zhong; Han, Lina; Bolon, Brad N.; Blum, William; Mrózek, Krzysztof; Carroll, Andrew J.; Perrotti, Danilo; Andreeff, Michael; Caligiuri, Michael A.; Konopleva, Marina; Garzon, Ramiro; Bloomfield, Clara D.; Marcucci, Guido

    2014-01-01

    Aberrant expression of the secreted protein, acidic, cysteine-rich (osteonectin) (SPARC) gene, which encodes a matricellular protein that participates in normal tissue remodeling, is associated with a variety of diseases including cancer, but the contribution of SPARC to malignant growth remains controversial. We previously reported that SPARC was among the most upregulated genes in cytogenetically normal acute myeloid leukemia (CN-AML) patients with gene-expression profiles predictive of unfavorable outcome, such as mutations in isocitrate dehydrogenase 2 (IDH2-R172) and overexpression of the oncogenes brain and acute leukemia, cytoplasmic (BAALC) and v-ets erythroblastosis virus E26 oncogene homolog (ERG). In contrast, SPARC was downregulated in CN-AML patients harboring mutations in nucleophosmin (NPM1) that are associated with favorable prognosis. Based on these observations, we hypothesized that SPARC expression is clinically relevant in AML. Here, we found that SPARC overexpression is associated with adverse outcome in CN-AML patients and promotes aggressive leukemia growth in murine models of AML. In leukemia cells, SPARC expression was mediated by the SP1/NF-κB transactivation complex. Furthermore, secreted SPARC activated the integrin-linked kinase/AKT (ILK/AKT) pathway, likely via integrin interaction, and subsequent β-catenin signaling, which is involved in leukemia cell self-renewal. Pharmacologic inhibition of the SP1/NF-κB complex resulted in SPARC downregulation and leukemia growth inhibition. Together, our data indicate that evaluation of SPARC expression has prognosticative value and SPARC is a potential therapeutic target for AML. PMID:24590286

  16. Hematopoietic differentiation is required for initiation of acute myeloid leukemia

    PubMed Central

    Ye, Min; Zhang, Hong; Yang, Henry; Koche, Richard; Staber, Philipp B.; Cusan, Monica; Levantini, Elena; Welner, Robert S.; Bach, Christian S.; Zhang, Junyan; Krivtsov, Andrei; Armstrong, Scott A.; Tenen, Daniel G.

    2015-01-01

    Summary Mutations in acute myeloid leukemia (AML)-associated oncogenes often arise in hematopoietic stem cells (HSCs) and promote acquisition of leukemia stem cell (LSC) phenotypes. However, as LSCs often share features of lineage-restricted progenitors, the relative contribution of differentiation status to LSC transformation is unclear. Using murine MLL-AF9 and MOZ-TIF2 AML models, we show that myeloid differentiation to granulocyte macrophage progenitors (GMPs) is critical for LSC generation. Disrupting GMP formation by deleting the lineage-restricted transcription factor C/EBPa blocked normal granulocyte formation and prevented initiation of AML. However, restoring myeloid differentiation in C/EBPa mutants with inflammatory cytokines reestablished AML transformation capacity. Genomic analyses of GMPs, including gene expression and H3K79me2 profiling in conjunction with ATAC-seq, revealed a permissive genomic environment for activation of a minimal transcription program shared by GMPs and LSCs. Together, these findings show myeloid differentiation is a prerequisite for LSC formation and AML development, providing insights for therapeutic development. PMID:26412561

  17. Cannabinoids induce incomplete maturation of cultured human leukemia cells

    SciTech Connect

    Murison, G.; Chubb, C.B.H.; Maeda, S.; Gemmell, M.A.; Huberman, E.

    1987-08-01

    Monocyte maturation markers were induced in cultured human myeloblastic ML-2 leukemia cells after treatment for 1-6 days with 0.03-30 ..mu..M ..delta../sup 9/-tetrahydrocannabinol (THC), the major psychoactive component of marijuana. After a 2-day or longer treatment, 2- to 5-fold increases were found in the percentages of cells exhibiting reactivity with either the murine OKM1 monoclonal antibody of the Leu-M5 monoclonal antibody, staining positively for nonspecific esterase activity, and displaying a promonocyte morphology. The increases in these differentiation markers after treatment with 0.03-1 ..mu..M THC were dose dependent. At this dose range, THC did not cause an inhibition of cell growth. The THC-induced cell maturation was also characterized by specific changes in the patterns of newly synthesized proteins. The THC-induced differentiation did not, however, result in cells with a highly developed mature monocyte phenotype. However, treatment of these incompletely matured cells with either phorbol 12-myristate 13-acetate of 1..cap alpha..,25-dihydroxycholecalciferol, which are inducers of differentiation in myeloid leukemia cells (including ML-2 cells), produced cells with a mature monocyte morphology. The ML-2 cell system described here may be a useful tool for deciphering critical biochemical events that lead to the cannabinoid-induced incomplete cell differentiation of ML-2 cells and other related cell types. Findings obtained from this system may have important implications for studies of cannabinoid effects on normal human bone-marrow progenitor cells.

  18. Characterization of Leukemia-Inducing Genes Using a Proto-Oncogene/Homeobox Gene Retroviral Human cDNA Library in a Mouse In Vivo Model.

    PubMed

    Jang, Su Hwa; Lee, Sohyun; Chung, Hee Yong

    2015-01-01

    The purpose of this research is to develop a method to screen a large number of potential driver mutations of acute myeloid leukemia (AML) using a retroviral cDNA library and murine bone marrow transduction-transplantation system. As a proof-of-concept, murine bone marrow (BM) cells were transduced with a retroviral cDNA library encoding well-characterized oncogenes and homeobox genes, and the virus-transduced cells were transplanted into lethally irradiated mice. The proto-oncogenes responsible for leukemia initiation were identified by PCR amplification of cDNA inserts from genomic DNA isolated from leukemic cells. In an initial screen of ten leukemic mice, the MYC proto-oncogene was detected in all the leukemic mice. Of ten leukemic mice, 3 (30%) had MYC as the only transgene, and seven mice (70%) had additional proto-oncogene inserts. We repeated the same experiment after removing MYC-related genes from the library to characterize additional leukemia-inducing gene combinations. Our second screen using the MYC-deleted proto-oncogene library confirmed MEIS1and the HOX family as cooperating oncogenes in leukemia pathogenesis. The model system we introduced in this study will be valuable in functionally screening novel combinations of genes for leukemogenic potential in vivo, and the system will help in the discovery of new targets for leukemia therapy.

  19. PS-341 in Treating Patients With Refractory or Relapsed Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Chronic Myeloid Leukemia in Blast Phase, or Myelodysplastic Syndrome

    ClinicalTrials.gov

    2013-01-22

    Adult Acute Promyelocytic Leukemia (M3); Blastic Phase Chronic Myelogenous Leukemia; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia

  20. Feline Leukemia Virus Infection Requires a Post-Receptor Binding Envelope-Dependent Cellular Component▿

    PubMed Central

    Hussain, Naveen; Thickett, Kelly R.; Na, Hong; Leung, Cherry; Tailor, Chetankumar S.

    2011-01-01

    Gammaretrovirus receptors have been suggested to contain the necessary determinants to mediate virus binding and entry. Here, we show that murine NIH 3T3 and baby hamster kidney (BHK) cells overexpressing receptors for subgroup A, B, and C feline leukemia viruses (FeLVs) are weakly susceptible (101 to 102 CFU/ml) to FeLV pseudotype viruses containing murine leukemia virus (MLV) core (Gag-Pol) proteins, whereas FeLV receptor-expressing murine Mus dunni tail fibroblast (MDTF) cells are highly susceptible (104 to 106 CFU/ml). However, NIH 3T3 cells expressing the FeLV subgroup B receptor PiT1 are highly susceptible to gibbon ape leukemia virus pseudotype virus, which differs from the FeLV pseudotype viruses only in the envelope protein. FeLV resistance is not caused by a defect in envelope binding, low receptor expression levels, or N-linked glycosylation. Resistance is not alleviated by substitution of the MLV core in the FeLV pseudotype virus with FeLV core proteins. Interestingly, FeLV resistance is alleviated by fusion of receptor-expressing NIH 3T3 and BHK cells with MDTF or human TE671 cells, suggesting the absence of an additional cellular component in NIH 3T3 and BHK cells that is required for FeLV infection. The putative FeLV-specific cellular component is not a secreted factor, as MDTF conditioned medium does not alleviate the block to FeLV infection. Together, our findings suggest that FeLV infection requires an additional envelope-dependent cellular component that is absent in NIH 3T3 and BHK cells but that is present in MDTF and TE671 cells. PMID:21917946

  1. Feline leukemia virus infection requires a post-receptor binding envelope-dependent cellular component.

    PubMed

    Hussain, Naveen; Thickett, Kelly R; Na, Hong; Leung, Cherry; Tailor, Chetankumar S

    2011-12-01

    Gammaretrovirus receptors have been suggested to contain the necessary determinants to mediate virus binding and entry. Here, we show that murine NIH 3T3 and baby hamster kidney (BHK) cells overexpressing receptors for subgroup A, B, and C feline leukemia viruses (FeLVs) are weakly susceptible (10(1) to 10(2) CFU/ml) to FeLV pseudotype viruses containing murine leukemia virus (MLV) core (Gag-Pol) proteins, whereas FeLV receptor-expressing murine Mus dunni tail fibroblast (MDTF) cells are highly susceptible (10(4) to 10(6) CFU/ml). However, NIH 3T3 cells expressing the FeLV subgroup B receptor PiT1 are highly susceptible to gibbon ape leukemia virus pseudotype virus, which differs from the FeLV pseudotype viruses only in the envelope protein. FeLV resistance is not caused by a defect in envelope binding, low receptor expression levels, or N-linked glycosylation. Resistance is not alleviated by substitution of the MLV core in the FeLV pseudotype virus with FeLV core proteins. Interestingly, FeLV resistance is alleviated by fusion of receptor-expressing NIH 3T3 and BHK cells with MDTF or human TE671 cells, suggesting the absence of an additional cellular component in NIH 3T3 and BHK cells that is required for FeLV infection. The putative FeLV-specific cellular component is not a secreted factor, as MDTF conditioned medium does not alleviate the block to FeLV infection. Together, our findings suggest that FeLV infection requires an additional envelope-dependent cellular component that is absent in NIH 3T3 and BHK cells but that is present in MDTF and TE671 cells.

  2. Inhibition of Feline leukemia virus replication by the integrase inhibitor Raltegravir.

    PubMed

    Cattori, Valentino; Weibel, Beatrice; Lutz, Hans

    2011-08-26

    The oncogenic gammaretrovirus Feline leukemia virus (FeLV) has been the leading cause of death among domestic cats until the introduction of efficient diagnostics and vaccines in the late 1980s. So far, no efficient treatment for viremic animals is available. Hence, use of the FeLV model to evaluate antiretroviral therapies applied to HIV is a timely task. The efficacy of the integrase inhibitor Raltegravir, which is widely used for the treatment of HIV in humans, has been assessed in vitro for the FeLV-A/Glasgow-1 strain. EC(50) values for FeLV-A inhibition in feline cell lines are in the range of that observed for HIV and xenotropic murine leukemia virus-related gammaretrovirus. Therefore, Raltegravir may be a potential therapeutical agent for felids with progressive FeLV infection.

  3. Acute Lymphoblastic Leukemia (ALL) (For Parents)

    MedlinePlus

    ... 1- to 2-Year-Old Acute Lymphoblastic Leukemia (ALL) KidsHealth > For Parents > Acute Lymphoblastic Leukemia (ALL) A A A What's in this article? About ... child will develop acute lymphoblastic, or lymphoid, leukemia (ALL). This is the most common type of childhood ...

  4. Small-Molecule Disruption of the Myb/p300 Cooperation Targets Acute Myeloid Leukemia Cells.

    PubMed

    Uttarkar, Sagar; Piontek, Therese; Dukare, Sandeep; Schomburg, Caroline; Schlenke, Peter; Berdel, Wolfgang E; Müller-Tidow, Carsten; Schmidt, Thomas J; Klempnauer, Karl-Heinz

    2016-12-01

    The transcription factor c-Myb is essential for the proliferation of hematopoietic cells and has been implicated in the development of leukemia and other human cancers. Pharmacologic inhibition of Myb is therefore emerging as a potential therapeutic strategy for these diseases. By using a Myb reporter cell line, we have identified plumbagin and several naphthoquinones as potent low-molecular weight Myb inhibitors. We demonstrate that these compounds inhibit c-Myb by binding to the c-Myb transactivation domain and disrupting the cooperation of c-Myb with the coactivator p300, a major driver of Myb activity. Naphthoquinone-induced inhibition of c-Myb suppresses Myb target gene expression and induces the differentiation of the myeloid leukemia cell line HL60. We demonstrate that murine and human primary acute myeloid leukemia cells are more sensitive to naphthoquinone-induced inhibition of clonogenic proliferation than normal hematopoietic progenitor cells. Overall, our work demonstrates for the first time the potential of naphthoquinones as small-molecule Myb inhibitors that may have therapeutic potential for the treatment of leukemia and other tumors driven by deregulated Myb. Mol Cancer Ther; 15(12); 2905-15. ©2016 AACR. ©2016 American Association for Cancer Research.

  5. Divergent effects of supraphysiologic Notch signals on leukemia stem cells and hematopoietic stem cells.

    PubMed

    Chiang, Mark Y; Shestova, Olga; Xu, Lanwei; Aster, Jon C; Pear, Warren S

    2013-02-07

    The leukemia stem cell (LSC) hypothesis proposes that a subset of cells in the bulk leukemia population propagates the leukemia.We tested the LSC hypothesis in a mouse model of Notch-induced T-cell acute lymphoblastic leukemia (T-ALL) in which the tumor cells were largely CD4+ CD8+ T cells. LSC activity was enriched but rare in the CD8+ CD4 HSA(hi) immature single-positive T-cell subset. Although our murine T-ALL model relies on transduction of HSCs, we were unable to isolate Notch-activated HSCs to test for LSC activity. Further analysis showed that Notch activation in HSCs caused an initial expansion of hematopoietic and T-cell progenitors and loss of stem cell quiescence, which was followed by progressive loss of long-term HSCs and T-cell production over several weeks. Similar results were obtained in a conditional transgenic model in which Notch activation is induced in HSCs by Cre recombinase. We conclude that although supraphysiologic Notch signaling in HSCs promotes LSC activity in T-cell progenitors, it extinguishes self-renewal of LT-HSCs. These results provide further evidence for therapeutically targeting T-cell progenitors in T-ALL while also underscoring the need to tightly regulate Notch signaling to expand normal HSC populations for clinical applications.

  6. Preclinical validation: LV/IL-12 transduction of patient leukemia cells for immunotherapy of AML

    PubMed Central

    Huang, Ju; Liu, Yuanfeng; Au, Bryan C; Barber, Dwayne L; Arruda, Andrea; Schambach, Axel; Rothe, Michael; Minden, Mark D; Paige, Christopher J; Medin, Jeffrey A

    2016-01-01

    Interleukin-12 (IL-12) is a potent cytokine that may be harnessed to treat cancer. To date, nearly 100 IL-12-based clinical trials have been initiated worldwide. Yet systemic administration of IL-12 is toxic. Different strategies are being developed to reduce such toxicities by restricting IL-12 distribution. Our previous studies employed lentivector-mediated expression of murine IL-12 in tumor cells and demonstrated effective protection in both mouse leukemia and solid tumor challenge models. In this study, we carried out preclinical validation studies using a novel lentivector to engineer expression of human IL-12 in acute myeloid leukemia blast cells isolated from 21 patients. Acute myeloid leukemia cells were transduced with a bicistronic lentivector that encodes the human IL-12 cDNA as a fusion, as well as a LNGFR (ΔLNGFR)/mutant thymidylate kinase cassette as a marking and cell-fate control element. A range of 20–70% functional transduction efficiencies was achieved. Transduced acute myeloid leukemia cells produced bioactive IL-12 protein and displayed dose-dependent sensitivity to the prodrug 3′-azido-3′-deoxythymidine. In vitro immortalization assays using transduced mouse hematopoietic stem cells demonstrated minimal genotoxic risk from our IL-12 vector. Scale-up transduction and cell processing was subsequently validated in a GMP facility to support our (now approved) Clinical Trial Application (CTA). PMID:27933304

  7. Acute leukemias of ambiguous origin.

    PubMed

    Porwit, Anna; Béné, Marie C

    2015-09-01

    This session of the Society for Hematopathology/European Association for Haematopathology Workshop focused on acute leukemias of ambiguous origin. We provide an overview of mixed-phenotype acute leukemia (MPAL) as recognized in the current World Health Organization classification and summarize diagnostic criteria for major categories of MPAL: B/myeloid, T/myeloid, B/T, and B/T/myeloid. Most MPAL cases submitted were B/myeloid and T/myeloid MPAL, the most frequent types, but three cases of B/T MPAL were also submitted, and examples of all categories are illustrated. We emphasize that a comprehensive approach to immunophenotyping is required to accurately establish the diagnosis of MPAL. Flow cytometry immunophenotyping using a large panel of antibodies is needed as well as confirmatory immunohistochemical analysis and cytochemistry studies for myeloperoxidase and nonspecific esterase. We discuss technical issues in determining blast lineage and possible pitfalls in MPAL diagnosis. In particular, rare cases of B-acute lymphoblastic leukemia (B-ALL) can express myeloperoxidase but are otherwise consistent with B-ALL and should be treated as such. Last, we review the differential diagnosis between acute undifferentiated leukemia and acute myeloid leukemia with minimal differentiation. There was an agreement that diagnosis of MPAL can be challenging, especially if applied flow cytometry panels are not comprehensive enough. Copyright© by the American Society for Clinical Pathology.

  8. Nilotinib and Combination Chemotherapy in Treating Patients With Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia or Blastic Phase Chronic Myelogenous Leukemia

    ClinicalTrials.gov

    2015-10-29

    B-cell Adult Acute Lymphoblastic Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Philadelphia Chromosome Positive Adult Precursor Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia

  9. Treosulfan, Fludarabine Phosphate, and Total-Body Irradiation Before Donor Stem Cell Transplant in Treating Patients With High-Risk Acute Myeloid Leukemia, Myelodysplastic Syndrome, Acute Lymphoblastic Leukemia

    ClinicalTrials.gov

    2017-04-05

    Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Blastic Phase Chronic Myelogenous Leukemia; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Childhood Chronic Myelogenous Leukemia; Childhood Myelodysplastic Syndromes; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

  10. Leukemia inhibitory factor (LIF).

    PubMed

    Nicola, Nicos A; Babon, Jeffrey J

    2015-10-01

    Leukemia inhibitory factor (LIF) is the most pleiotropic member of the interleukin-6 family of cytokines. It utilises a receptor that consists of the LIF receptor β and gp130 and this receptor complex is also used by ciliary neurotrophic growth factor (CNTF), oncostatin M, cardiotrophin1 (CT1) and cardiotrophin-like cytokine (CLC). Despite common signal transduction mechanisms (JAK/STAT, MAPK and PI3K) LIF can have paradoxically opposite effects in different cell types including stimulating or inhibiting each of cell proliferation, differentiation and survival. While LIF can act on a wide range of cell types, LIF knockout mice have revealed that many of these actions are not apparent during ordinary development and that they may be the result of induced LIF expression during tissue damage or injury. Nevertheless LIF does appear to have non-redundant actions in maternal receptivity to blastocyst implantation, placental formation and in the development of the nervous system. LIF has also found practical use in the maintenance of self-renewal and totipotency of embryonic stem cells and induced pluripotent stem cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Chronic Lymphocytic Leukemia

    PubMed Central

    Motta, Marina; Wierda, William G.; Ferrajoli, Alessandra

    2015-01-01

    Patients with purine analogue-refractory chronic lymphocytic leukemia (CLL) have short survival and limited treatment options. Defining the best salvage strategies for this population is challenging, because limited data are available from clinical trials, and because studies have enrolled mixed populations (patients with recurrent and refractory disease or patients with refractory disease and Richter transformation). Moreover, patients with refractory CLL have a high incidence of unfavorable molecular and clinical features, such as high-risk genomic profiles, unmutated immunoglobulin heavy-chain genes, expression of zeta-chain-associated protein kinase 70, and bulky lymphadenopathies. These patients are also severely immunosuppressed because of the underlying disease and the treatments received, and experience a high rate of infectious complications that pose an additional difficulty in selecting treatment. Despite these challenges, in parallel with better characterizations of the biologic features of refractory CLL, the number of available treatment modalities for this population has increased. Several chemoimmunotherapy combinations have been developed, and novel agents with a different mechanism of action are being investigated in clinical trials. Furthermore, allogeneic stem cell transplantation with nonmyeloablative conditioning regimens is a therapeutic strategy that is increasingly offered to patients with refractory CLL. PMID:19536902

  12. Leukemia Inhibitory Factor (LIF)

    PubMed Central

    Nicola, Nicos A; Babon, Jeffrey J

    2015-01-01

    Leukemia inhibitory factor (LIF) is the most pleiotropic member of the interleukin-6 family of cytokines. It utilises a receptor that consists of the LIF receptor β and gp130 and this receptor complex is also used by ciliary neurotrophic growth factor (CNTF), oncostatin M, cardiotrophin1 (CT1) and cardiotrophin-like cytokine (CLC). Despite common signal transduction mechanisms (JAK/STAT, MAPK and PI3K) LIF can have paradoxically opposite effects in different cell types including stimulating or inhibiting each of cell proliferation, differentiation and survival. While LIF can act on a wide range of cell types, LIF knockout mice have revealed that many of these actions are not apparent during ordinary development and that they may be the result of induced LIF expression during tissue damage or injury. Nevertheless LIF does appear to have non-redundant actions in maternal receptivity to blastocyst implantation, placental formation and in the development of the nervous system. LIF has also found practical use in the maintenance of self-renewal and totipotency of embryonic stem cells and induced pluripotent stem cells. PMID:26187859

  13. PLASMA CELL LEUKEMIA

    PubMed Central

    de Larrea, Carlos Fernandez; Kyle, Robert A.; Durie, Brian GM; Ludwig, Heinz; Usmani, Saad; Vesole, David H.; Hajek, Roman; Miguel, Jésus San; Sezer, Orhan; Sonneveld, Pieter; Kumar, Shaji K.; Mahindra, Anuj; Comenzo, Ray; Palumbo, Antonio; Mazumber, Amitabha; Anderson, Kenneth C.; Richardson, Paul G.; Badros, Ashraf Z.; Caers, Jo; Cavo, Michele; LeLeu, Xavier; Dimopoulos, Meletios A.; Chim, CS; Schots, Rik; Noeul, Amara; Fantl, Dorotea; Mellqvist, Ulf-Henrik; Landgren, Ola; Chanan-Khan, Asher; Moreau, Philippe; Fonseca, Rafael; Merlini, Giampaolo; Lahuerta, JJ; Bladé, Joan; Orlowski, Robert Z.; Shah, Jatin J.

    2014-01-01

    Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic-pathologic entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10 9/L) of plasma cells in the peripheral blood. It is proposed that the thresholds for diagnosis be reexamined and consensus recommendations are made for diagnosis, as well as, response and progression criteria. Induction therapy needs to begin promptly and have high clinical activity leading to rapid disease control in an effort to minimize the risk of early death. Intensive chemotherapy regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem-cell transplantation (HDT/ASCT) if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding of the pathogenesis of PCL. PMID:23288300

  14. Idarubicin and Cytarabine With or Without Bevacizumab in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia

    ClinicalTrials.gov

    2013-01-23

    Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Childhood Acute Basophilic Leukemia; Childhood Acute Eosinophilic Leukemia; Childhood Acute Erythroleukemia (M6); Childhood Acute Megakaryocytic Leukemia (M7); Childhood Acute Monoblastic Leukemia (M5a); Childhood Acute Monocytic Leukemia (M5b); Childhood Acute Myeloblastic Leukemia With Maturation (M2); Childhood Acute Myeloblastic Leukemia Without Maturation (M1); Childhood Acute Myelomonocytic Leukemia (M4); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia; Untreated Childhood Acute Myeloid Leukemia and Other Myeloid Malignancies

  15. Adipose tissue attracts and protects acute lymphoblastic leukemia cells from chemotherapy

    PubMed Central

    Pramanik, Rocky; Sheng, Xia; Ichihara, Brian; Heisterkamp, Nora; Mittelman, Steven D.

    2013-01-01

    Obesity is associated with an increased risk of acute lymphoblastic leukemia (ALL) relapse. Using mouse and cell co-culture models, we investigated whether adipose tissue attracts ALL to a protective microenvironment. Syngeneically implanted ALL cells migrated into adipose tissue within ten days. In vitro, murine ALL cells migrated towards adipose tissue explants and 3T3-L1 adipocytes. Human and mouse ALL cells migrated toward adipocyte conditioned media, which was mediated by SDF-1α. In addition, adipose tissue explants protected ALL cells against daunorubicin and vincristine. Our findings suggest that ALL migration into adipose tissue could contribute to drug resistance and potentially relapse. PMID:23332453

  16. Characterization of a protein that binds multiple sequences in mammalian type C retrovirus enhancers.

    PubMed Central

    Sun, W; O'Connell, M; Speck, N A

    1993-01-01

    Mammalian type C retrovirus enhancer factor 1 (MCREF-1) i