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

RNA pseudoknot structural motifs could have implications for a wide range of biological processes of RNAs. In this study, the potential RNA pseudoknots just downstream from the known and suspected retroviral frame-shift sites were predicted in the Rous sarcoma virus, primate immunodeficiency viruses (HIV-1, HIV-2, and SIV), equine infectious anemia virus, visna virus, bovine leukemia virus, human T-cell leukemia virus (types I and II), mouse mammary tumor virus, Mason-Pfizer monkey virus, and simian SRV-1 type-D retrovirus. Also, the putative RNA pseudoknots were detected in the gag-pol overlaps of two retrotransposons of Drosophila, 17.6 and gypsy, and the mouse intracisternal A particle. For each sequence, the thermodynamic stability and statistical significance of the secondary structure involved in the predicted tertiary structure were assessed and compared. Our results show that the stem-loop structures in the pseudoknots are both thermodynamically highly stable and statistically significant relative to other such configurations that potentially occur in the gag-pol or gag-pro and pro-pol junction domains of these viruses (300 nucleotides upstream and downstream from the possible frameshift sites are included). Moreover, the structural features of the predicted pseudoknots following the frameshift site of pro-pol overlaps of the HTLV-1 and HTLV-2 retroviruses are structurally well conserved. The occurrence of eight compensatory base changes in the tertiary interaction of the two related sequences allow the conservation of their tertiary structures in spite of the sequence divergence. The results support the possible control mechanism for frameshifting proposed by Brierley et al. and Jacks et al.
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PMID:RNA pseudoknots downstream of the frameshift sites of retroviruses. 166 82

The specificities of the antisera raised in the CDF1 mice that had been immunized with the P1.HTR tumor cells xenogenized by transfection with recombinant H-2Kb-erbB gene were studied. The antisera cross-reacted with a broad range of tumor cell lines maintained either in vitro or in vivo in an immunofluorescence assay. However, they did not react at all with syngeneic normal tissue cells from thymus, spleen, bone marrow and fetal liver. Even though antigens related to the murine leukemia virus and murine mammary tumor virus (MuMTV) were demonstrated in many of the tumor cell lines tested with specific antibodies, these antigens did not seem to be primarily involved in the anti-P1.HTR antibody activity. The 74 kDa molecule, which was precipitated by the anti-P1.HTR anti-serum from the surface radiolabeled cell extract of P1.HTR tumor and was discriminated from the 70 kDa molecule precipitated by the anti-MuMTV serum, was widely distributed among various tumor cell lines tested, but was absent in normal tissue cells. In contrast to the extensive cross-reaction by the antibody, the cytotoxic T lymphocyte generated in the P1.HTR immune mice were shown to be specific to the P1.HTR tumor, and the 98 kDa molecule was precipitated by the anti-P1.HTR serum from the P1.HTR tumor but not from other tumors tested. It is suggested from these results that the 98 kDa molecule is a candidate for an individual tumor-specific transplantation antigen, and is immunodominant for inducing cytotoxic T lymphocytes to coexisting intrinsic retroviral antigens and other serologically cross-reactive tumor antigens.
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PMID:Characterization of the individual and cross-reactive antigens involved in the anti-tumor immunity induced by use of an H-2K-erbB recombinant gene transfectant. 167 57

Southern blot analysis revealed no difference between the DNA from radiation-induced thymic lymphomas and DNA from normal NFS mice. The probes used in the Southern blot analyses used a murine leukemia virus (MuLV) env DNA probe (pXenv), which specifically hybridizes with xenotropic and recombinant viral env genes, and mouse mammary tumor virus (MMTV) DNA probes (MMTV gag-pol, MMTV env, and MMTV LTR). This suggests that radiation leukemogenesis was not associated with gross alteration of the organization of these retroviral genomes. In DNA from radiation-induced thymic lymphoma, there was no indication of gross rearrangement in the common integration site of MuLV, pim-1, or in the common integration sites of MMTV, int-1 and int-2. Dot blot analysis of RNA from radiation-induced thymic lymphomas and normal thymuses demonstrated that there was no substantial difference between them in the expression of retroviral sequences, pim-1, pvt-1, int-1, or int-2, although transcripts that could be hybridized to the retroviral sequences were slightly elevated in some radiation-induced thymic lymphomas. These results show that radiation leukemogenesis does not appear to involve the activation of endogenous type-C and type-B retroviruses.
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PMID:Lack of evidence for the involvement of type-C and type-B retroviruses in radiation leukemogenesis of NFS mice. 169 Apr 35

Human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type I (HTLV-I) were purified by sucrose density gradient centrifugation in the presence of 1 mM EDTA. Pelleted gradient fractions were analyzed for total protein, total Gag capsid protein, and total zinc. Zinc was found to copurify and concentrate with the virus particles. Through successive cycles of resuspending in buffer containing EDTA and repelleting, the zinc content remained constant at about 1.7 mol of zinc per mol of Gag protein. Proteins from purified virus (HIV-1 and HTLV-I) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted to polyvinylidene fluoride paper, and probed with 65ZnCl2. Viral nucleocapsid (NC) proteins (HIV-1 p7NC and HTLV-I p15NC) bound 65Zn2+. Other retroviruses, including simian immunodeficiency virus, equine infectious anemia virus, bovine leukemia virus, Moloney murine leukemia virus, mouse mammary tumor virus, and Mason-Pfizer monkey virus, were found to contain amounts of zinc per milligram of total protein similar to those found in HIV-1 and HTLV-I. Collectively, these data support the hypothesis that retroviral NC proteins function as zinc finger proteins in mature viruses.
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PMID:Tightly bound zinc in human immunodeficiency virus type 1, human T-cell leukemia virus type I, and other retroviruses. 173 Nov 11

Hexadecylphosphocholine (HPC) and its analogs with a longer alkyl chain (C18 and C20) were examined for antineoplastic activity in the murine tumor models P388 leukemia, B 16 melanoma, the mammary carcinoma C3H and Ca 755, and the human MT-1 mammary tumor in nude mice. The maximum tolerated doses were determined and found to be higher in mice than in rats. The toxicity of the alkylphosphocholines increases with chain length. The murine mammary carcinoma C3H and the human MT-1 mammary carcinoma showed response to HPC whereas the classical screening models did not respond to the synthetic lipids. Furthermore, HPC showed activity in a mitoxantrone-resistant P388 leukemia. Treated/control values between 120 and 160% in survival time could be obtained following a daily application of the lipid. Examination of the activity of possible cleavage products of HPC gave no information about the mechanism of action of the used etherlipids. Liposomes with encapsulated mitoxantrone, formed from alkylphosphocholines, cholesterol and dicetylphosphate had the same activity against P388 mouse leukemia as the free drug. The hemolytic activity of the three lipids tested in vivo was assumed to be related to toxic deaths of single animals; hemolytic activity was observed to be sometimes independent of schedule and dose.
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PMID:Antitumor effects of alkylphosphocholines in different murine tumor models: use of liposomal preparations. 179 99

The comparative carcinogenicities of N-hydroxy-N-acetyl-1-aminopyrene, N-acetyl-1-aminopyrene, and 1-, 2-, and 4-nitropyrene were determined following i.p. injection into weaning female CD rats (67 mumol/kg body weight in dimethyl sulfoxide; 3 times/week for 4 weeks). At sacrifice 61 weeks after the first injection the incidences of malignant mammary tumors were increased significantly to 45 and 24% in the 4-nitropyrene- and N-hydroxy-N-acetyl-2-aminofluorene-treated groups, respectively. Cellular altered foci in the liver were increased significantly in the N-acetyl-1-aminopyrene-, N-hydroxy-N-acetyl-1-aminopyrene-, and N-hydroxy-N-acetyl-2-aminofluorene- treated groups; the latter two compounds also led to significantly increased formation of hyperplastic nodules in this organ. Significant increases in leukemia induction were observed in animals treated with 2-nitropyrene or N-hydroxy-N-acetyl-2-aminofluorene. In an experiment designed to compare the influence of the route of administration on the carcinogenic potential of this agent, 1-nitropyrene was injected i.p. or s.c. into weanling female CD rats (100 mumol/kg body weight; once a week for 4 weeks). The animals were sacrificed at 87 to 90 weeks after the first treatment. The incidences of mammary gland tumors in animals receiving injections of 1-nitropyrene by either route (59%) were significantly higher than in solvent-injected controls (37%). The incidences of adenocarcinoma in the i.p. 1-nitropyrene group (28%) and fibroadenoma in the s.c. 1-nitropyrene group (52%) were significantly higher than in the control animals (7 and 27%, respectively). These data suggest that the demonstration of the weak carcinogenicity of 1-nitropyrene is probably more a function of the length of the observation period than of the routes of administration used here. A further exploration of the effect of the route of administration involved treatment of weanling female CD rats by direct injection of 1-, 2-, or 4-nitropyrene into the mammary fat pads. A total of 2.04 mumol of the nitrocompound in dimethyl sulfoxide was injected into the mammary glands under each of the 6 left nipples. The right mammary glands were treated with the solvent only. Injections of the thoracic nipple areas were carried out on day 1; inguinal areas were treated on day 2. The animals were sacrificed after 77 weeks. The number of mammary tumor-bearing animals (23 of 28), the number with fibroadenoma (15 of 28), and the number with adenocarcinoma (19 of 28) were significantly increased in the 4-nitropyrene-treated group as compared with animals treated with only dimethyl sulfoxide.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Comparative carcinogenicities of 1-, 2-, and 4-nitropyrene and structurally related compounds in the female CD rat. 203 29

The avian endogenous env gene product blocks the surface receptor and, as a result, cells become immune to related exogenous retroviruses. On the other hand, the same sequence can be included in the pathogenic retrovirus genome, as shown by oligonucleotide mapping. However, since the complete env gene sequence was not known, the comparison of genomic nucleotide sequences was not possible. Therefore an avian endogenous provirus with an intact env gene was cloned from a chicken gene bank and the regions coding for the C terminus of the gp85 and gp37 proteins were sequenced. Comparison of this sequence with those of other retroviruses proved that one of the pathogenic viruses associated with osteopetrosis is a cross between avian endogenous virus and Rous sarcoma virus. Retroviruses and, especially, endogenous retroviruses are traditionally of the most developed models of viral carcinogenesis. Many endogenous retroviruses are implicated in neoplastic transformation of the cell. For instance, endogenous mouse mammary tumor virus of some inbred lines appears to be the only causative agent in these mammary cancers. Other even nonpathogenic murine endogenous retroviruses are involved in the origination of MCF-type recombinant acute leukosis viruses. Some endogenous retroviruses are implicated in the transduction or activation of cellular protooncogenes. Our interest in endogenous viruses is based on their ability to make cells resistant to exogenous retroviruses. Expression of their major envelope glycoprotein leads to cellular surface receptor blockage and imparts immunity to infection by the related leukemia retroviruses. This problem is quite elaborated for chicken endogenous virus RAV-O (7-9).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Avian endogenous provirus (ev-3) env gene sequencing: implication for pathogenic retrovirus origination. 216 Nov 59

A murine retrovirus which expresses the v-mycOK10 oncogene under the control of the dexamethasone-regulatable mouse mammary tumor virus (MMTV) promoter has been constructed. In this vector, denoted pMImyc, the Moloney Murine leukemia virus (MoMuLV) sequences required for virus replication, integration and packaging were kept, while all the elements for transcription regulation were derived from the MMTV long terminal repeat (LTR). After transfection of NIH 3T3 fibroblasts with this construct, a cell line was isolated in which the level of v-myc RNAs were increased 60 fold by dexamethasone. Kinetic studies showed that this induction can be maintained for up to 12 hours of hormone treatment. After infection with MoMuLV as a helper virus, and in the presence of dexamethasone, the production of pMImyc RNA, estimated by slot blot analysis, was equivalent to about 10(3) viral particles/ml.
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PMID:Glucocorticoids regulate expression of the v-mycOK10 oncogene in a murine retroviral vector with chimeric MoMuLV-MMTV LTRs. 216 66

A line of transgenic mice that express the human adenovirus type 12 E1A and E1B genes under the regulatory control of the mouse mammary tumor virus long terminal repeat was studied. Mice from this line develop olfactory neuroblastomas at approximately 6 months of age. Large numbers of type C retrovirus (ecotropic murine leukemia virus) particles were found in the tumor rosettes. No similar examples of virus activation were identified in tumors from other transgenic experiments. Examination of spontaneous olfactory neuroblastomas from three domestic cats also demonstrated retrovirus in tumor rosettes.
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PMID:Activation of retrovirus in transgenic mice: association with development of olfactory neuroblastoma. 216 6

We report the construction of 17 recombinant inbred (RI) strains of mice derived from the progenitor strains NZB/BINRe and SM/J and the typing of this RI strain set, designated NXSM, for 58 loci distributed on 16 autosomes and the X chromosome. Two backcrosses involving NZB/BINJ and SM/J were constructed to confirm chromosomal assignments and determine gene orders suggested from NXSM RI strain data. From these results we recommend that chromosomal assignments and gene orders suggested from analyses of RI strain sets be confirmed using data obtained by other means. We also typed NZB/BINJ and SM/J for mammary tumor proviral (Mtv) loci. Both strains share three previously described Mtv loci: Mtv-7, Mtv-14 and Mtv-17. In addition, NZB/BINJ contains the previously described Mtv-3 and Mtv-9 loci and two new Mtv proviral loci: Mtv-27 located on chromosome (Chr) 1 and Mtv-28 located on the X chromosome. SM/J contains the previously described loci Mtv-6 and Mtv-8. Four LTR, mink cell focus-forming murine leukemia viral loci were identified and mapped: Ltrm-1 on Chr 12, Ltrm-2 on Chr 16, Ltrm-3 on Chr 5, and Ltrm-4 on Chr 13. The Tgn locus was positioned proximal to the Ly-6 locus on Chr 15.
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PMID:The NXSM recombinant inbred strains of mice: genetic profile for 58 loci including the Mtv proviral loci. 216 66


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