We investigated inhibition of Moloney leukemia virus 10 (MOV10) upon xenotropic murine leukemia virus-related virus (XMRV) and made a preliminary study of the mechanism of action. Using transfection, infection, western blotting and real-time polymerase chain reaction, we found that MOV10 inhibited XMRV replication. Using MOV10 overexpressed in viral producer cells, MOV10 was shown to reduce the infectivity of XMRV. MOV10 could be incorporated into XMRV, suggesting that MOV10 could undergo encapsidation by XMRV during viral assembly. MOV10 could also restrict the DNA production of XMRV in target cells. We found that the putative RNA-helicase domain of MOV10 maintained most of its XMRV inhibition. These results suggest that MOV10 could be required during the retroviral lifecycle. Perturbation of MOV10 disrupts the generation of infectious viral particles, suggesting that MOV10 has broad antiretroviral activity. Hence, MOV10 could be actively involved in host defense against retroviral infection.
Humans ; Moloney murine leukemia virus ; physiology ; RNA Helicases ; physiology ; Virus Replication

To produce the reverse transcriptase of moloney murine leukemia virus (MMLV-RT) through gene recombination, MMLV-rt gene was amplified by polymerase chain reaction (PCR) with specifically designed primers bearing restriction enzyme sites. Five mutation sites increasing the solution of the target protein were introduced through Site-directed mutation. After verification by sequencing, the gene was cloned into the expression vector pET15b to construct the recombinant plasmid pET15b-MMLV-rt. Purified MMLV-RT was obtained by affinity chromatography (Ni3+-NTA beads). Molecular weight and purity of MMLV-RT were analyzed with SDS-PAGE. Enzyme activity was characterized with RT-PCR. We successfully constructed the recombinant plasmid pET15b-MMLV-rt and obtained the MMLV-RT fusion protein with 6His on the N-terminus. Recombinant protein was purified through Ni3+-NTA beads based affinity chromatography, the purity of which was 96%. The Activity of the enzyme was high. MMLV-RT of 96% purity was obtained with the prokaryotic expression technique, which serves as the basis for mass production of this enzyme.
Animals ; Mice ; Moloney murine leukemia virus ; enzymology ; genetics ; RNA-Directed DNA Polymerase ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; metabolism ; Recombination, Genetic

B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial-mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.
Animals ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphoma, B-Cell/genetics* ; Male ; Mice ; Moloney murine leukemia virus/genetics* ; Mutagenesis, Insertional/genetics* ; Polycomb Repressive Complex 1/genetics* ; Prostatic Neoplasms/genetics*

INTRODUCTION AND OBJECTIVES: Retinoic acid (RA) is known as a potent chemopreventive agent in bladder tumor. Recently, RA has gained attention for up-regulation of transduced gene expression via long terminal repeat (LTR) transcriptional promotion. In this study, we investigated the possible dual effect of RA, growth inhibition and up-regulation of transduced gene expression which contains LTR promoter in human bladder carcinoma cell lines. MATERIALS AND METHODS: Human bladder carcinoma cell lines CY-24, J-82, HT-1197, ATCC) were transduced with Moloney murine leukemia virus containing cDNA of TNF-alpha. The growth of transduced and parent cell line was measured by tetrazolium based colorimetric assay (MTF). Transduced TNF-alpha gene expression was determined by ELISA method. RESULTS: TNF-alpha production was increased approximately twofold after treatment with RA (10 uM) in all three cell lines. This increase was dependent on RA concentration. RA treatment of transduced and parent cell line resulted in dose dependent inhibition of cell proliferation(up to 80% inhibitionwith 10 uM RA) in all parental and transduced cell lines. CONCLUSIONS: These results indicate that RA shows dual effect in cytokine gene transduced bladder carcinoma cells with retroviral vector containing LTR promoter and could be a supplement to the gene therapy of bladder cancer.
Cell Line* ; DNA, Complementary ; Enzyme-Linked Immunosorbent Assay ; Gene Expression* ; Genetic Therapy ; Humans* ; Moloney murine leukemia virus ; Parents ; Terminal Repeat Sequences ; Tretinoin* ; Tumor Necrosis Factor-alpha* ; Up-Regulation ; Urinary Bladder Neoplasms* ; Urinary Bladder* ; Zidovudine

OBJECTIVES: To evaluate the effect of glutathione(GSH) on lead induced modulation of nitric oxide(NO) synthesis, and to examine how lead modulates NO production in macrophages. METHODS: This study was observed in a culture of RAW 264.7 cells, which originated from a tumor in a Balb/c mouse that was induced by the Abelson murine leukemia virus. The compounds investigated were lead chloride, N-acetyl-cystein(NAC), and Buthionine Sulfoximine(BSO). RESUJLTS: ATP synthesis in RAW 264.7 cells was unchanged by each lead concentration exposure in a dose dependent manner. The NO synthesis was decreased when exposed to lead(PbCl2) concentration 0.5 micro M. The presence of 300 micro M NAC, used as a pretreatment in the culture medium, caused the recovery of the lead induced decrease in NO synthesis, but in the presence of 300 micro M BSO as a pretreatment, there was no recoverey. Pretreatment with NAC and BSO had no affect on ATP synthesis at any of the lead concentrations used. CONCLUSIONS: These results indicated that GSH has a protective effect toward lead toxicity, and suggested that the inhibition of NO production in macrophage due to lead toxicity may be related to cofactors of iNOS (inducible nitric oxide synthase)
Abelson murine leukemia virus ; Acetylcysteine ; Adenosine Triphosphate ; Animals ; Buthionine Sulfoximine ; Glutathione* ; Macrophages ; Mice ; Nitric Oxide

OBJECTIVES: To evaluate the effect of glutathione(GSH) on lead induced modulation of nitric oxide(NO) synthesis, and to examine how lead modulates NO production in macrophages. METHODS: This study was observed in a culture of RAW 264.7 cells, which originated from a tumor in a Balb/c mouse that was induced by the Abelson murine leukemia virus. The compounds investigated were lead chloride, N-acetyl-cystein(NAC), and Buthionine Sulfoximine(BSO). RESUJLTS: ATP synthesis in RAW 264.7 cells was unchanged by each lead concentration exposure in a dose dependent manner. The NO synthesis was decreased when exposed to lead(PbCl2) concentration 0.5 micro M. The presence of 300 micro M NAC, used as a pretreatment in the culture medium, caused the recovery of the lead induced decrease in NO synthesis, but in the presence of 300 micro M BSO as a pretreatment, there was no recoverey. Pretreatment with NAC and BSO had no affect on ATP synthesis at any of the lead concentrations used. CONCLUSIONS: These results indicated that GSH has a protective effect toward lead toxicity, and suggested that the inhibition of NO production in macrophage due to lead toxicity may be related to cofactors of iNOS (inducible nitric oxide synthase)
Abelson murine leukemia virus ; Acetylcysteine ; Adenosine Triphosphate ; Animals ; Buthionine Sulfoximine ; Glutathione* ; Macrophages ; Mice ; Nitric Oxide

The purpose of this study was to develop a multiplex PCR that can detect porcine endogenous retrovirus (PERV) proviral genes (pol, envA, envB, envC) and porcine mitochondrial DNA, using a dual priming oligonucleotide (DPO) system. The primer specifically detected the PERV proviral genes pol, envA, envB, envC, and porcine mitochondrial DNA only in samples of pig origin. The sensitivity of the primer was demonstrated by simultaneous amplification of all 5 target genes in as little as 10 pg of pig DNA containing PERV proviral genes and mitochondrial DNA. The multiplex PCR, when applied to field samples, simultaneously and successfully amplified PERV proviral genes from liver, blood and hair root samples. Thus, the multiplex PCR developed in the current study using DPO-based primers is a rapid, sensitive and specific assay for the detection and subtyping of PERV proviral genes.
Animals ; DNA Primers/genetics ; DNA, Mitochondrial/*genetics ; Gammaretrovirus/*genetics ; Polymerase Chain Reaction/*methods ; Proviruses/classification/*genetics ; Sensitivity and Specificity ; Sus scrofa/*genetics/*virology

The Bcr-Abl oncogene is produced by the reciprocal translocation between c-Abl gene on chromosome 9 and the Bcr gene on chromosome 22 in human genome. The encoded Bcr-Abl fusion protein is responsible for the pathogenesis of certain human leukemias. Abelson murine leukemia virus (A-MuLV) is a retrovirus that could lead to transformation of B lymphocyte in mice, and v-Abl is the oncogene of A-MuLV. Abl oncoproteins (such as Bcr-Abl and v-Abl) play critical roles in tumorigenesis of certain cell types. Several signal transduction pathways, including JAK/STAT/Pim, PI3K/AKT/mTOR and RAS/RAF/MEK signaling pathway, are involved in Abl-mediated tumorigenesis. In addition, Abl-mediated tumorigenesis is associated with mutation or abnormal modification of key signal molecules as well as dysregulation of some critical long noncoding RNAs (lncRNAs). Here, we review the molecular mechanisms by which Abl oncogenes activate three major signaling pathways, and provide a scientific basis for therapy of Abl oncoprotein-induced tumors.
Abelson murine leukemia virus ; Animals ; Cell Transformation, Neoplastic ; Fusion Proteins, bcr-abl ; Genes, abl ; Humans ; Phosphatidylinositol 3-Kinases

OBJECTIVETo investigate the roles of mouse erythroid differentiation and denucleation factor (MEDDF), a novel factor cloned in our laboratory recently, in erythroid terminal differentiation.

METHODSMouse erythroleukemia (MEL) cells were transfected with eukaryotic expression plasmid pcDNA-MEDDF. Then we investigated the changes on characteristics of cell growth by analyzing cells growth rate, mitotic index and colony-forming rate in semi-solid medium. The expressions of c-myc and beta-globin genes were analysed by semi-quantitative RT-PCR.

RESULTSMEL cells transfected with pcDNA-MEDDF showed significant lower growth rate, mitotic index, and colony-forming rate in semi-solid medium (P<0.01). The percentage of benzidine-positive cells was 32.8% after transfection. The expression of beta-globin in cells transfected with pcDNA-MEDDF was 3.43 times higher than that of control (MEL transfected with blank vector, pcDNA3.1), and the expression of c-myc decreased by 66.3%.

CONCLUSIONSMEDDF can induce differentiation of MEL cell and suppress its malignancy.

Activins ; genetics ; pharmacology ; Animals ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Friend murine leukemia virus ; Globins ; biosynthesis ; genetics ; Inhibin-beta Subunits ; genetics ; pharmacology ; Leukemia, Erythroblastic, Acute ; metabolism ; pathology ; Mice ; Proto-Oncogene Proteins c-myc ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; Transfection ; Tumor Cells, Cultured

Xenotransplantation, as a potential solution to the shortage of human organs, is associated with a number of concerns including immunologic rejection and xenogenic infection. While the pigs are considered the most suitable organ source for xenotransplantation, there is a potential public health risk due to zoonosis. Among the known porcine zoonotic microbes, Porcine Endogenous Retrovirus (PERV) is the most considerable virus. PERV belongs to the Gammaretrovirus and has been divided into three groups (A, B, and C). To characterize the gag of PERVs, we isolated the genomic DNAs from three pig breeds (Birkshire, Duroc, and Yorkshire) and two types of SPF miniature pigs. About 1.5 kb fragments covering full length of gag were amplified and cloned into T-vector. A total of 38 clones were obtained and sequenced. Nucleotide sequences were analyzed and phylogenetic trees were constructed from the nucleotide and deduced amino acids. PERV-A, -B and -C were present in the proportion of 47, 19 and 34%, respectively. Regardless of origin or subgroups, gag clones showed highly homology in nucleotide and deduced amino acid sequences. Deduced amino acids sequence alignments showed typical conserve sequences, Cys-His box and processing sites. Among analyzed clones, about 28% of isolates had the correct open reading frame. To test the functional expression of Gag protein, gag was subcloned into expression vector and confirmed its expression in HeLa cell. This research provides the fundamental information about molecular characteristics of gag gene and functional Gag protein related xenotropic PERVs.
Amino Acid Sequence ; Amino Acids ; Base Sequence ; Clone Cells ; DNA ; Endogenous Retroviruses* ; Gammaretrovirus ; Gene Products, gag ; Genes, gag* ; HeLa Cells ; Humans ; Korea* ; Open Reading Frames ; Public Health ; Sequence Alignment ; Swine* ; Transplantation, Heterologous