Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| use of a glucocorticoid-inducible promoter for expression of herpes simplex virus type 1 glycoprotein gc1, a cytotoxic protein in mammalian cells. | abundant expression of herpes simplex virus type 1 glycoprotein gc (gc1) in transfected mammalian cells has not previously been achieved, possibly because gc1 protein is toxic to cells. to approach this problem, the gc1 coding sequence was placed under the control of the weak but inducible glucocorticoid-responsive promoter from the mouse mammary tumor virus (mmtv) long terminal repeat (ltr). as controls to evaluate for gc1 cytotoxicity, the mmtv ltr promoter was used to express glycoprotein gd1 ... | 1989 | 2548078 |
| high level expression of p55, a thyroid hormone binding protein which is homologous to protein disulfide isomerase in a retroviral vector. | to develop an efficient system for a high level expression of a human cellular thyroid hormone binding protein (p55) in eukaryotic cells, a full-length p55 cdna was inserted into a harvey murine sarcoma virus-derived vector (phtbr) and transfected into mouse nih 3t3 cells. the expressed p55 has a molecular weight of 55,000 and is recognized by the human specific anti-p55 monoclonal antibody. similar to the endogenous p55, the expressed p55 is localized on endoplasmic reticulum and nuclear envelo ... | 1989 | 2553014 |
| acutely transforming retroviruses as carcinogens in mouse embryos. | spontaneous and induced transmission of oncogenic retroviruses from parents to offspring is well documented in mammals, as exemplified by murine leukaemia viruses. in addition, it is now common knowledge that transgenic mice, carrying viral and cellular transforming genes, can show unusual tumour incidences and can transmit this character to successive generations. the present report deals with the occurrence of tumours in rodents exposed directly in utero to murine sarcoma viruses (msv). attent ... | 1989 | 2553597 |
| glucocorticoid-enhanced neoplastic transformation of human keratinocytes by human papillomavirus type 16 and an activated ras oncogene. | human papillomaviruses (hpv) are known etiological agents of benign proliferation of the skin and mucosa (papillomas and warts). they have also been implicated in the development of cervical dysplasia and anogenital carcinoma. the close association of hpv type 16 dna with the majority of cervical carcinomas suggests the involvement of the virus in this type of cancer. we have developed an in vitro multistep model for human epithelial cell carcinogenesis. primary human epidermal keratinocytes acq ... | 1989 | 2556855 |
| 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine (pmedap): a novel agent with anti-human immunodeficiency virus activity in vitro and potent anti-moloney murine sarcoma virus activity in vivo. | 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine (pmedap) is a potent inhibitor of the replication of human immunodeficiency virus (hiv) in human t-lymphocyte mt-4 cells (50% effective dose: 2 microm). pmedap strongly inhibited moloney murine sarcoma virus (msv)-induced transformation of murine c3h/3t3 embryo fibroblasts and caused a dose-dependent suppression of tumor formation and mortality in newborn mice inoculated with msv. even at a dose as low as 0.25 mg/kg/day, pmedap effected a significan ... | 1989 | 2559845 |
| synthesis and secretion of plasminogen activators and collagenases in human cells transformed by kirsten murine sarcoma virus and n-methyl-n'-nitro-n-nitrosoguanidine. | the secretion of elevated levels of proteinases is considered to be a distinct property of most transformed cells. the cellular and secreted levels of plasminogen activators and collagenases have been examined in the nonmalignant human osteosarcoma (hos), the malignant kirsten murine sarcoma virus transformed (khos/np), the temperature sensitive revertant of virus transformed hos (khos-240s) and n-methyl-n'-nitro-n-nitrosoguanidine transformed hos (mnng/hos) clones. virus and mnng transformed cl ... | 1989 | 2561462 |
| transformation-sensitive and growth-related changes of protein synthesis in ref52 cells. a two-dimensional gel analysis of sv40-, adenovirus-, and kirsten murine sarcoma virus-transformed rat cells using the ref52 protein database. | two-dimensional gels of normal and virally transformed ref52 cells have been quantified and compared using the quest system for construction and analysis of protein databases. the ref52 protein map is based on more than 1600 high quality spots, and the relative amounts of these proteins are studied in 79 gels representing 12 major experiments. ref52 cells transformed by sv40, adenovirus, and kirsten murine sarcoma virus (kimsv) are compared to normal ref52 cells at several stages of growth from ... | 1989 | 2564397 |
| expression of a multidrug resistance-adenosine deaminase fusion gene. | a novel fusion gene has been created in which the expression of a dominant selectable marker, the human multidrug resistance gene, is directly linked to the expression of human adenosine deaminase cdna. the chimeric gene was inserted between the long terminal repeats of a harvey murine sarcoma virus expression vector and used to transfect drug-sensitive human kb carcinoma cells. transfectants were selected in increasing concentrations of colchicine and found to contain multiple copies of the int ... | 1989 | 2565338 |
| the mos proto-oncogene maps near the centromere on mouse chromosome 4. | the mos proto-oncogene, the cellular homolog of the transforming gene of moloney murine sarcoma virus, was originally assigned to mouse chromosome 4 using independent panels of mouse/hamster somatic cell hybrids. by in situ hybridization to metaphase chromosomes and standard genetic backcrosses, we have confirmed this assignment and determined that mos maps near the centromere in a region devoid of other markers. we have also identified a restriction fragment length polymorphism (rflp) that defi ... | 1989 | 2570024 |
| in vitro cleavage of pr65gag by the moloney murine leukaemia virus proteolytic activity yields p30 whose nh2-terminal sequence is identical to virion p30. | in vitro cleavage of gazdar murine sarcoma virus pr65gag, which has all of the antigenic determinants of moloney murine leukaemia virus pr65gag, i.e. p15, p12, p30 and p10, by the moloney murine leukaemia virus proteolytic activity yielded a p30 whose partial nh2-terminal sequence was identical to moloney murine leukaemia virus. both [3h]leucine-labelled and unlabelled pr65gag were used to generate the cleaved p30. | 1985 | 2578553 |
| amphotropic retrovirus vector transfer of the v-ras oncogene to human hematopoietic and stromal cells in continuous bone marrow cultures. | human continuous bone marrow cultures were established from intraoperative marrow specimens and infected with amphotropic murine leukemia virus (am-mulv) pseudotypes of kirsten or harvey murine sarcoma virus, and the biologic effects were compared with mouse continuous bone marrow cultures. cultures were tested for production of total nonadherent granulocytes and granulocyte-macrophage progenitor cells (gm-cfuc); virus replication by supernatant reverse transcriptase activity; percentage of adhe ... | 1985 | 2578839 |
| neoplastic transformation of human epidermal keratinocytes by ad12-sv40 and kirsten sarcoma viruses. | recent investigations have begun to dissect the number and nature of genetic alterations associated with cancer cells. in the present study, primary human epidermal keratinocytes acquired indefinite life-span in culture but did not undergo malignant conversion in response to infection with a hybrid of adenovirus 12 and simian virus 40. addition of kirsten murine sarcoma virus, which contains a k-ras oncogene, to these cells induced morphological alterations associated with the acquisition of neo ... | 1985 | 2579430 |
| isotype distribution and specificity of the antibody response to primary moloney murine sarcoma virus infection in balb/c mice. | the development and isotype distribution of moloney murine leukemia virus (m-mulv)-specific serum antibodies following primary inoculation with moloney murine sarcoma/leukemia virus (m-musv/m-mulv) in adult balb/c mice have been investigated using an enzyme-linked immunosorbent assay (elisa). the primary antibody responses to m-musv/m-mulv consisted of the igm, igg2a, igg2b, and igg3 isotypes; no m-mulv-specific serum igg1 or iga antibodies were detected. the detectable antibody response was bip ... | 1989 | 2673279 |
| altered ganglioside expression in ras-oncogene-transformed cells. | alteration of ganglioside composition in mouse balb/3t3 cells transformed either by dna transfection with viral k-, h-, or cellular h-ras oncogene, or by infection with the k-ras oncogene-carrying murine sarcoma virus (ki-ksv) was studied using a highly sensitive thin-layer chromatography/enzyme immunostaining method. marked common decreases in the content of gd3 ganglioside and the increase of its metabolic precursor gm3 were bound in balb/3t3 cell lines transformed by either k- or h-ras oncoge ... | 1989 | 2674112 |
| multiple harvey-ras genes in the bovine genome. | three different harvey-ras (ha-ras) genes have been identified in the bovine genome by screening a lambda phage-bovine dna library with the ras gene of the harvey murine sarcoma virus. the genes have been characterized by hybridization and heteroduplex analysis with both the viral and human ha-ras genes. based on heteroduplex mapping, the putative direction of transcription and the approximate position of the coding regions of the bovine genes were established. two genes, bovine ha-ras 1 and 2, ... | 1989 | 2687766 |
| definition of the human raf amino-terminal regulatory region by deletion mutagenesis. | activation of transforming potential of the cellular raf gene has uniformly been associated with the deletion of amino-terminal coding sequences. in order to determine whether 5' truncation alone could activate cellular raf, we constructed 21 human c-raf-1 cdnas with variable bal 31-generated deletions distal to a moloney murine sarcoma virus long terminal repeat and a consensus translation initiation sequence. the deletions ranged from 136 to 1,399 nucleotides of coding sequence and shortened t ... | 1989 | 2710120 |
| avian retroviral long terminal repeats bind ccaat/enhancer-binding protein. | dna-protein interactions involving enhancer and promoter sequences within the u3 regions of several avian retroviral long terminal repeats (ltrs) were studied by dnase i footprinting. the rat ccaat/enhancer-binding protein, c/ebp, bound to all four viral ltrs examined. the rous sarcoma virus binding site corresponded closely to the 5' limit of the ltr enhancer; nucleotides -225 to -188 were protected as a pair of adjacent binding domains. the fujinami sarcoma virus ltr bound c/ebp at a single si ... | 1989 | 2725492 |
| synthesis and antiviral activity of 3'-c-cyano-3'-deoxynucleosides. | a series of 3'-c-cyano-3'-deoxynucleosides have been synthesized and evaluated as antiviral agents. reaction of 2',5'-bis-o-(tert-butyldimethylsilyl)-beta-d-erythro-pentofuranos- 3'-ulosyl derivatives of uracil, 4-n-acetylcytosine, and adenine with sodium cyanide gave a mixture of epimeric cyanohydrins, which after 3'-deoxygenation yielded the corresponding 3'-c-cyano-3'-deoxy-beta-d-xylo-pentofuranosyl derivatives 10. these compounds were epimerized to the corresponding beta-d-ribo-pentofuranos ... | 1989 | 2754698 |
| the block of thyroglobulin synthesis, which occurs upon transformation of rat thyroid epithelial cells, is at the transcriptional level and it is associated with methylation of the 5' flanking region of the gene. | transformation of rat thyroid epithelial cells by kirsten murine sarcoma virus results in the block of certain thyroid differentiated functions, such as synthesis and secretion of thyroglobulin. our studies, performed by a run-on assay, demonstrate that this block occurs at the transcriptional level. we also demonstrate the de novo methylation of two methylation-sensitive sites, located within the 5' end regulatory sequences of the thyroglobulin gene, in transformed cells, in the absence of any ... | 1989 | 2767151 |
| distinct segments within the enhancer region collaborate to specify the type of leukemia induced by nondefective friend and moloney viruses. | the nondefective moloney and friend murine leukemia viruses induce t-cell lymphomas and erythroleukemias, respectively, after being injected into newborn nfs mice. in previous studies, we showed that the distinct disease specificities of the two viruses could be switched by exchanging a small segment, about 200 nucleotides in length, encompassing their enhancer regions. this segment included the direct repeat sequence and an adjacent gc-rich region of about 20 nucleotides defined in studies of m ... | 1989 | 2783259 |
| growth stimulation of 3t3 fibroblasts by cystatin. | treatment of cultures of mouse 3t3 fibroblasts with cystatin c, a thiol-proteinase inhibitor isolated from chicken egg white, resulted in an enhanced rate of cell proliferation. this stimulation was demonstrated using two independent assay systems: (a) assessment of total cell number and (b) measurement of [3h]thymidine incorporated into acid-precipitable dna. in both assays, the dose-response curves of cystatin stimulation showed a rising function that plateaued at a concentration of approximat ... | 1989 | 2783311 |
| b cell precursors are present in the thymus during early development. | an in vitro system for transforming immature lymphoid cells present in the thymus at early development has been established. by phenotype analysis of the transformants obtained, we observed that b cell precursors, susceptible to abelson murine leukemia virus (a-mulv)- or harvey murine sarcoma virus (h-musv)-induced lymphogenesis, were present at high frequency in the fetal thymus of balb/c mice. these precursors recolonized alymphoid thymus lobes in vitro, as do t cell precursors. it was further ... | 1989 | 2784111 |
| harvey-ras mediated neoplastic development in the mouse mammary gland. | the role of a harvey-ras oncogene in mammary epithelial neoplasia was examined by infecting primary cultures of normal mouse mammary epithelial cells with either the harvey murine sarcoma virus (psi 2hamsv) alone or with hamsv plus a helper virus. the biological effects of expression of the ha-ras oncogene were determined by transplanting the infected cells into gland-cleared mammary fat pads of virgin balb/c mice. expression of the ha-ras oncogene was correlated with the development of mammary ... | 1989 | 2784851 |
| mouse xenotropic viruses can inhibit cell transformation. | mammalian type c retroviruses can be detected by their induction of foci of cell transformation in s+i - cells. we have noted that certain subtypes of the mouse xenotropic type c retrovirus (mulv) inhibit this cell alteration. this inhibition, associated with intact virions, is irreversible and gives the infected cells a phenotype of uninfected cells. in comparison to the transformed cells, the inhibited cultures showed primarily a decrease in murine sarcoma virus (msv) progeny production concom ... | 1987 | 2820140 |
| rat transformation-associated proteins (tap) induced by moloney murine sarcoma virus interact with specific receptors on normal rat kidney cells. | in this report, data are presented to show that transformation-associated proteins (tap) secreted from the transformed 6m2 cells have mitogenic activities in the stimulation of dna synthesis and proliferation of normal rat kidney (nrk-2) cells and of nonpermissively grown 6m2 cells. tap also bound specifically to nrk-2 cells with a binding dissociation constant (kd) of 1.4 pm. approximately 2 x 10(5) binding sites per cell were found. therefore, tap may represent a set of virally-induced growth ... | 1987 | 2820404 |
| elevated levels of a specific class of nuclear phosphoproteins in cells transformed with v-ras and v-mos oncogenes and by cotransfection with c-myc and polyoma middle t genes. | transformation of a rat thyroid epithelial cell line (frtl5-c12) with kirsten and harvey murine sarcoma viruses (carrying the ras oncogenes) results in elevated levels of three perchloric acid-soluble nuclear phosphoproteins. these three proteins are also induced to high levels in the pc-c13 thyroid epithelial cell line when transformed by the myeloproliferative sarcoma virus (carrying the v-mos oncogene) and when transformed by transfection with the c-myc proto-oncogene followed by infection wi ... | 1987 | 2820715 |
| optimizing gene expression in bpv-transformed cells: effects of cell type on enhancer/promoter interaction. | we have compared several combinations of enhancers and promoters in expressing the chloramphenicol acetyl transferase gene in transient assays, in mouse c127, the most widely used host cell for the bovine papilloma virus (bpv) expression vector. of the various combinations tested, the unit comprised of the sv40 enhancer and adenovirus type 2 major late promoter (mlp) was the most active in bpv transformed c127 cells. we further demonstrate that untransformed and bpv transformed c127 cells respon ... | 1987 | 2821493 |
| the p55 protein affected by v-mos expression is vimentin. | rabbit antiserum prepared against a cyclic 19-amino-acid peptide predicted from the sequence of the viral mos gene (v-mos) of moloney murine sarcoma virus not only recognized v-mos gene products but also specifically detected a 55,000-mr polypeptide expressed in a variety of cells that grow on solid surfaces. this normal cellular protein, previously shown to be reduced in amount in cells expressing the v-mos gene, was found to be the intermediate filament structural protein, vimentin. this concl ... | 1987 | 2822968 |
| murine retrovirus-induced malignant histiocytosis, an experimental model for the disease in humans. | the hematopoietic disregulation in adult mice induced by the malignant histiocytosis sarcoma virus (mhsv) and the harvey murine sarcoma virus (ha-musv), which both possess c-ha-ras-related oncogenic sequences, was investigated. spleen focus formation induced by mhsv and ha-musv was not restricted by the fv-2 resistance locus in congenic ddd and c57bl/6 mice, unlike leukemogenesis induced by friend virus, rauscher virus, and the myeloproliferative sarcoma virus (mpsv). c57bl/6 mice were much more ... | 1987 | 2823012 |
| identification of a rat liver nuclear protein that binds to the enhancer core element of three animal viruses. | this report describes the identification and purification of a nuclear protein from rat liver that binds selectively to dna sequences associated with several animal virus enhancers. the binding activity was tracked by direct dnase i footprinting through four steps of biochemical fractionation. these procedures led to the identification of a polypeptide species exhibiting an apparent molecular weight of 20 kd that accounts for enhancer binding activity. dnase i and dimethyl sulfate footprinting a ... | 1987 | 2824279 |
| temperature-sensitive cellular mutant for expression of mrna from murine retrovirus. | the cellular mutant b812 isolated from a fisher rat cell line shows temperature sensitivity of focus formation induced by various retroviruses such as recombinant murine retrovirus containing the middle t gene of polyomavirus (pymlv), kirsten murine sarcoma virus, moloney murine sarcoma virus, and recombinant murine retrovirus containing the src gene of rous sarcoma virus. b812 cells, however, show normal ability to proliferate and synthesize protein at the nonpermissive temperature, suggesting ... | 1988 | 2824838 |
| human p45ia1 upstream regulatory sequences expressing the chloramphenicol acetyltransferase gene. effect of ha-msv enhancer and comparison of transient with stable transformation assays. | upstream sequences of the human p450ia1 gene were inserted into a promoterless expression vector (psvo-cat) containing the chloramphenicol acetyltransferase (cat) gene, with and without the harvey murine sarcoma virus (ha-msv) core enhancer, and either plasmid was transfected into human breast carcinoma mcf-7 and mda-231 and mouse hepatoma hepa-1 cell lines. in most instances constitutive and inducible cat activities in the transient cat expression assay were similar (within 3-fold) to those in ... | 1987 | 2825673 |
| site-selective camp analogs induce nuclear translocation of the rii camp receptor protein in ha-musv-transformed nih/3t3 cells. | site-selective camp analogs, depending on the position of their substituents on the adenine ring, selectively bind to either site 1 or site 2 of the known camp binding sites of protein kinase. treatment of harvey murine sarcoma virus-transformed nih/3t3 cells with such site-selective analogs results in growth inhibition and phenotypic reversion, and the combination of a c-8 thio or halogen analog (site 1 selective) with an n6 analog (site 2 selective) produces a synergistic effect. we report her ... | 1987 | 2826232 |
| reverse transformation of harvey murine sarcoma virus-transformed nih/3t3 cells by site-selective cyclic amp analogs. | eighteen site-selective camp analogs modified at either the c-8 position or the c-6 position were tested for their growth regulatory effects on the harvey murine sarcoma virus-transformed nih/3t3 clone 13-3b-4 cells grown in a serum-free defined medium. all 18 analogs, when tested individually, exhibited an appreciable growth inhibitory effect at micromolar concentrations. the most potent growth inhibitory analogs contained a thio moiety at the c-8 position. in general, c-6 analogs required 5-10 ... | 1988 | 2826444 |
| immortalization of human endothelial cells by murine sarcoma viruses, without morphologic transformation. | amphotropic murine leukemia virus pseudotypes of murine sarcoma viruses containing the ras or mos oncogenes were constructed to permit efficient introduction of the sarcoma virus genome into early-passage human umbilical vein endothelial cells. the resulting cell lines were morphologically and phenotypically unchanged, retaining properties characteristic of differentiated endothelial cells. for example, the cells in a kirsten sarcoma virus-modified line were found to biosynthesize and secrete vo ... | 1988 | 2826502 |
| a dna element responsible for the different tissue specificities of friend and moloney retroviral enhancers. | the transcriptional enhancers of the moloney murine sarcoma virus (musv) and moloney murine leukemia virus (mulv) have different cell type specificities from that of the friend mulv. while the three enhancers are approximately equally active in erythroid cells, the moloney musv and moloney mulv enhancers are 20- to 40-fold more active than the friend mulv enhancer in t-lymphoid cells. using mutant enhancers, we have shown that specific differences between the nucleotide sequences of the moloney ... | 1988 | 2826819 |
| trans-activation of the simian virus 40 enhancer by a px product of human t-cell leukemia virus type i. | a trans-acting factor, p40, of human t-cell leukemia virus type i profoundly potentiated the function of the enhancer from simian virus 40 but not polyomavirus and rous sarcoma and murine sarcoma viruses. this trans-activation was seen in a limited repertoire of cells, in contrast to trans-activation of the human t-cell leukemia virus type i enhancer by p40. | 1988 | 2826822 |
| synthesis of specific transformation-associated proteins (taps) in two rat cell lines is closely related to the expression of the v-mos gene product of moloney murine sarcoma virus (mo-msv). | the 6m2 cell line was established by transformation of normal rat kidney cells with the ts110 mutant of moloney murine sarcoma virus (mo-msv). p85gag-mos was found to be the only known viral-transforming protein in this cell system. previously, we described the detection in 6m2 cells of rat-specific transformation-associated proteins (taps) using a monoclonal antibody (mc). in this study, we used mc to investigate further the expression of taps at different temperatures and the time course of tu ... | 1987 | 2828268 |
| monoclonal antibody against ifn-gamma inhibits moloney murine sarcoma virus-specific cytotoxic t lymphocyte differentiation. | 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 lymph ... | 1988 | 2830339 |
| reduced protein kinase c activity in a ras-resistant cell line derived from ki-msv transformed cells. | we have examined phosphatidylinositol turnover and c-kinase distribution in a flat cellular ras-resistant cell line (c11) derived from kirsten murine sarcoma virus (ki-msv) transformed nih/3t3 cells (dt). this cell type has been shown to express high levels of the p21 ki-ras gene product yet is resistant to the transforming effects of this protein. our data indicate that c11 cells have reduced levels of total c-kinase activity when compared to nih/3t3 cells and do not retain the ability to phosp ... | 1987 | 2830575 |
| the in vitro and in vivo anti-retrovirus activity, and intracellular metabolism of 3'-azido-2',3'-dideoxythymidine and 2',3'-dideoxycytidine are highly dependent on the cell species. | cell lines derived from different species show striking differences in their sensitivity to the cytostatic and anti-retrovirus activity, as well as the intracellular metabolism, of 3'-azido-2',3'-dideoxythymidine (azddthd) and 2',3'-dideoxycytidine (ddcyd). azddthd and ddcyd are considerably more cytostatic to human (i.e. raji, molt/4f, ath8) cell lines than murine (i.e. l1210) cells. the intracellular levels of azddthd 5'-triphosphate and ddcyd 5'-triphosphate formed do not seem related to the ... | 1988 | 2830886 |
| integration and loss of a single v-ki-ras gene affects tumorigenic potential of human osteosarcoma cells. | the human osteosarcoma cell line te85 clone f-5 is not tumorigenic in vivo. its transformation with kirsten murine sarcoma virus (kimsv) (khos) confers full malignant properties and stable non-tumorigenic revertants of this khos cell line have been obtained. here we show that integration and expression of a single copy of the kimsv proviral dna, which is totally lost in the hos 240s revertant, is responsible for the acquisition of tumorigenicity. cytogenetic analysis and the absence of a residua ... | 1988 | 2831097 |
| kirsten murine sarcoma virus abolishes interferon gamma-induced class ii but not class i major histocompatibility antigen expression in a murine fibroblast line. | the effect of infecting fibroblasts with kirsten murine sarcoma virus/murine leukemia virus (ki-msv/mlv) on constitutive and ifn-gamma-induced h-2 antigen expression was investigated. the fibroblasts used were two established cell lines (c3h10t1/2 and balb/c3t3) and fresh embryo fibroblasts from c3h mice. class i antigens were expressed constitutively by balb/c3t3; infection with mlv, msv or the two together had little effect on this constitutive expression. class i antigens (h-2k, h-2d) were st ... | 1988 | 2831293 |
| analysis of metal-induced mutations altering the expression or structure of a retroviral gene in a mammalian cell line. | carcinogenic metal compounds, with the exception of chromium(vi), have been found to be poorly mutagenic in both prokaryotic and mammalian cell mutagenesis assays, yet they are clearly clastogenic (hansen and stern, 1984). thus, the role of metals as initiators in carcinogenesis has been difficult to delineate. in an effort to develop a model system capable of assaying dna damage caused by carcinogenic metals, we have investigated the role of nicl2, cdcl2, na2cro4, and nmu in a murine sarcoma vi ... | 1988 | 2832750 |
| activation of thermosensitive rna splicing and production of a heat-labile p85gag-mos kinase by the introduction of a specific deletion in murine sarcoma virus-124 dna. | murine sarcoma virus ts110 (musvts110) is a conditionally transformation-defective musv mutant lacking 1,487 bases found in its wild-type parent, musv-349 (musv-124). expression of the musvts110 v-mos gene product, p85gag-mos, requires splicing of the viral transcript to align the gag and mos genes in frame. however, this splice event is restricted to growth temperatures of 33 degrees c or lower. no splicing of the viral rna, no production of p85gag-mos, and, hence, no cell transformation is obs ... | 1988 | 2835496 |
| dibutyryl camp inhibits expression of transformation-related properties in kirsten murine sarcoma virus transformed balb/c-3t3 cells despite continued presence of p21v-ki-ras. | we studied the effects of simultaneous treatment with 0.1 mm n6, o2'-dibutyryl camp (dbcamp) and 1 mm theophylline on several transformation-specific properties and on levels of the kirsten murine sarcoma virus (ki-msv) transforming gene product p21v-ki-ras, in a ki-msv-transformed mouse cell line (balb/c-3t3, clone a31; ka31). the rate of logarithmic growth, cell motility, and final saturation density were reduced in dbcamp-treated ka31 cultures. capabilities for anchorage-independent growth we ... | 1988 | 2835972 |
| construction and characterization of a retroviral vector demonstrating efficient expression of cloned cdna sequences. | we describe the construction and properties of a retroviral expression vector, designated pmv-7, designed to transfer unselected cdnas and produce their encoded proteins in recipient cells. the vector is flanked by the long terminal repeats (ltrs) of the moloney murine sarcoma virus (msv) and contains the selectable drug resistance gene neo under the regulation of the herpes simplex virus (hsv) thymidine kinase (tk) promoter. unique eco ri and hind iii sites facilitate the introduction of sequen ... | 1988 | 2836147 |
| accelerated malignant conversion of human hbl-100 cells by the v-ki-ras oncogene. | the human epithelial hbl-100 cell line harbors sv40 genetic information and has an unlimited growth potential. despite displaying properties characteristic of transformation since its early in vitro passages, it is capable of producing progressively growing tumors in nude mice only after long-term culture. this is a reproducible phenomenon and apparently not the consequence of a selection of preexisting malignant cells. superinfection of early passage nontumorigenic hbl-100 cells with kirsten mu ... | 1988 | 2836229 |
| functional studies of newly synthesized benzoic acid derivatives: identification of highly potent retinoid-like activity. | three newly synthesized benzoic acid derivatives (terephthalic acid anilides, chalcone carboxylic acid, and azobenzene carboxylic acid), with a certain structural similarity to retinoic acid, were examined for their retinoid-like bioactivity and their capacity to bind to cellular retinoid binding proteins. two in vitro systems were used to evaluate their retinoid-like bioactivity: inhibition of adipose conversion of st 13 murine preadipose cells and growth promotion of murine sarcoma virus (msv) ... | 1988 | 2836439 |
| chemical and viral transformation of cultured skin fibroblasts from patients with familial polyposis coli. | treatment of skin fibroblasts from an fpc patient with 4nqo or mnng followed by sequential passaging caused morphological changes of the cells, which showed characteristics of transformed cells such as a high frequency of colony formation in agarose, increased growth ability, and chromosomal abnormalities. this and other fibroblast lines from 5 of 12 fpc patients had an increased susceptibility to 4nqo cytotoxicity, which was caused by enhanced 4nqo-reductase activity rather than by reduced dna ... | 1988 | 2836726 |
| substitution of the ltr of abelson murine leukemia virus does not alter the cell type of virally induced tumors. | the long terminal repeat (ltr) of the pre-b cell tropic abelson murine leukemia virus (a-mulv) was replaced with the ltr of the erythrotropic friend mulv or with the ltr of the erythropic/fibrotropic harvey murine sarcoma virus (ha-musv) to generate the viruses f-abl and h-abl, respectively. the parental a-mulv and the recombinant viruses induced pre-b cell lymphomas in susceptible mice with similar frequencies. recombinant virus-induced tumor dnas were analysed by nucleic acid hybridization and ... | 1988 | 2838788 |
| bifunctional activity of transforming growth factor type beta on the growth of nrk-49f cells, normal and transformed by kirsten murine sarcoma virus. | transformation of rat nrk-49f cells (49f) by kirsten murine sarcoma virus (ki-msv) renders these cells (ki-49f cells) capable of autonomous anchorage independent (ai) growth. as compared to nontransformed 49f cells, the transformation by ki-msv does not modify the cell response to transforming growth factor-beta (tgf-beta) in monolayer conditions, but alters it in a i growth conditions. the growth of nontransformed or ki-msv-transformed adherent 49f cells is slowed down by porcine tgf-beta, and ... | 1988 | 2840442 |
| transformation of bone marrow cells from e mu-myc transgenic mice by abelson murine leukemia virus and harvey murine sarcoma virus. | transgenic mice harboring a c-myc gene subjugated to the immunoglobulin heavy chain enhancer offer a unique opportunity to investigate whether deregulated myc expression potentiates the transformation of b lymphoid cells by other oncogenes. by assessing colony formation in semi-solid medium, we have compared the potential of bone marrow cells from e mu-myc mice and their normal littermates for transformation by harvey murine sarcoma virus and abelson murine leukemia virus. e mu-myc bone marrow y ... | 1988 | 2840624 |
| glucocorticoids facilitate the stable transformation of embryonal rat fibroblasts by a polyomavirus large tumor antigen-deficient mutant. | the addition of glucocorticoids to the growth medium could substitute for the expression of the polyomavirus large tumor antigen in the transformation of rat fibroblasts in vitro. after transfection with a large tumor antigen-deficient mutant of polyomavirus, pbc1051, high-frequency permanent transformation was observed, if the cells were grown in medium containing dexamethasone. growth of pbc1051-transfected rat fibroblasts was strictly dependent on the presence of glucocorticoids during the in ... | 1988 | 2840668 |
| skin papillomas and other neoplasms induced by murine sarcoma viruses in mid-gestation-infected mice. | during extensive investigations on the effects of oncogenic retroviruses in developing rodents, the ability of msv to mount a neoplastic response in cd-i swiss mouse embryos was determined. by infecting the animals directly in utero at selected stages of post-implantation development, we detected a peculiar reaction of the embryonal tissues to certain msvs: when mice were exposed to kimsv at mid-gestation, the newborn developed characteristic tumors, in addition to mesenchymal cell sarcomas, not ... | 1988 | 2841249 |
| harvey sarcoma virus genome contains no extensive sequences unrelated to those of other retroviruses except ras. | the harvey murine sarcoma virus genome contains two rat-derived sets of genetic information recombined with the moloney mouse leukemia virus. the rat sequences represent a ras oncogene and a rat vl30 element. the vl30 sequences have several discrete regions of similarity with retroviral sequences which were detected by searching a protein database for similarities with predicted polypeptide sequences from the vl30 regions. on the 5' side, the most similar sequences were those of feline sarcoma v ... | 1988 | 2841504 |
| influence of the deprivation of a single amino acid on cellular proliferation and survival in rat 3y1 fibroblasts and their derivatives transformed by a wide variety of agents. | we compared proliferation and survival of various syngeneic transformed cell lines under conditions of depletion of 15 amino acids in dulbecco-eagle's medium. we used a normal fibroblast line 3y1 and 22 transformed sublines of 3y1 which had been induced by one of seven transforming agents--simian virus 40, mouse polyomavirus, adenovirus type 12, e1a gene of adenovirus type 12, cdna of harvey murine sarcoma virus, rous sarcoma virus, or n-methyl-n'-nitro-n-nitrosoguanidine. unlike other untransfo ... | 1988 | 2844831 |
| cytoarchitecture of kirsten sarcoma virus-transformed rat kidney fibroblasts: butyrate-induced reorganization within the actin microfilament network. | murine sarcoma virus-transformed rat fibroblasts (knrk cells) undergo marked cytoarchitectural reorganization during in vitro exposure to sodium-n-butyrate (nab) resulting in restoration of (1) a more typical fibroblastoid morphology, (2) proper cell-to-cell orientation, and (3) substratum adherence. augmented cell spreading, involving greater than 90% of the population, was a function of culture density and time of exposure to nab (2 mm final concentration). induced cell spreading reflected a 2 ... | 1988 | 2844835 |
| serotonin as a major serum factor inducing the phospholipase c-mediated hydrolysis of phosphoinositides in normal rat kidney cells. | calf serum induced the phospholipase c-mediated hydrolysis of phosphoinositides in normal rat kidney (nrk) cells transformed by a temperature-sensitive kirsten murine sarcoma virus (tsk-nrk cells). various growth factors known to induce the phospholipase c reactions in other cell types, such as platelet-derived growth factor, fibroblast growth factor, epidermal growth factor, thrombin, vasopressin, bombesin, cholecystokinin, and prostaglandin f2 alpha, did not induce phospholipase c reactions in ... | 1988 | 2846156 |
| increased formation of unintegrated viral dna in skin fibroblasts from patients with familial polyposis coli shortly after infection with kirsten murine sarcoma virus. | skin fibroblasts from patients with familial polyposis coli (fpc) exhibit increased frequency of morphological transformation, anchorage-independent growth, and enhanced production of viral rna and viral particles after infection with murine sarcoma virus(murine leukemia virus), msv(mlv). these fpc fibroblasts form greater amounts of unintegrated viral dna as compared to normal fibroblasts during the first 4 to 24 hr after infection with kirsten msv(kimlv), suggesting that increased susceptibili ... | 1988 | 2846448 |
| cooperative transforming activities of ras, myc, and src viral oncogenes in nonestablished rat adrenocortical cells. | early-passage rat adrenocortical cells were infected with kirsten murine sarcoma virus and mmcv mouse myc virus, two retroviruses carrying the v-ki-ras and v-myc oncogenes, respectively. efficient morphological transformation required coinfection with the two viruses, was dependent on the presence of high serum concentrations, and was not immediately accompanied by growth in soft agar. the doubly infected cells coordinately acquired the capacity for anchorage- and serum-independent growth during ... | 1988 | 2846881 |
| phosphonylmethoxyethyl purine derivatives, a new class of anti-human immunodeficiency virus agents. | a study of the structure-activity relationship of a series of newly synthesized phosphonylmethoxyalkyl purine and pyrimidine derivatives revealed that several adenine derivatives substituted at the n9 position by a 2-phosphonylmethoxyethyl (pme) group inhibited human immunodeficiency virus (hiv)-induced cytopathogenicity and hiv antigen expression in vitro at concentrations significantly below the toxicity threshold for the host cells. in terms of anti-hiv potency in mt-4 cells, the pme 2,6-diam ... | 1988 | 2847636 |
| human papillomavirus type 16 cooperates with activated ras and fos oncogenes in the hormone-dependent transformation of primary mouse cells. | the effect of human papillomavirus (hpv) and activated oncogenes on the growth and morphology of primary baby mouse kidney (bmk) cells has been studied. early region dna from hpv types 16, 18, 31, and 33, but not type 6, under the transcriptional control of a heterologous, retroviral promoter cooperated with ej-ras to produce cell lines that gave rise to carcinomas in syngeneic immunocompetent animals. the same hpv constructs, when cotransfected with a plasmid containing sequences from the finke ... | 1988 | 2848240 |
| transformation/neodifferentiation of human skin fibroblasts by acute oncornaviruses and dexamethasone. | we demonstrated that the kirsten murine sarcoma virus (kimsv) and the harvey murine sarcoma virus (hamsv) converted human skin fibroblasts (hsf) into adipocytes. adipocytic conversion of hsf by kimsv and hamsv was dependent on the presence of glucocorticosteroids. the kirsten murine leukemia virus, the harvey murine sarcoma [corrected] virus and the amphotropic helper virus (ap292) were ineffective by themselves. balb murine sarcoma virus and moloney murine sarcoma virus were, to a lesser degree ... | 1988 | 2852128 |
| [the suppression of osteogenic differentiation markers in human osteosarcoma cells transformed by kirsten murine sarcoma virus]. | 1988 | 2855077 | |
| polykaryocytosis induced by amphotropic murine c-type virus (ap129) in sac-cells nonproductively transformed by moloney murine sarcoma virus (mo-msv). | nonproducer cells of stu mouse origin (sac) transformed with moloney murine sarcoma virus (mo-msv) and superinfected with the amphotropic murine c-type virus strain ap 129 unexpectedly formed polykaryocytes. the multinuclear giant cells appeared about 30 days after ap 129 infection as confirmed in three independently performed experiments. the majority of the sac-cells became involved in syncytium formation. the polykaryocytes disappeared during continued culture transfers. various cell lines ob ... | 1985 | 2859766 |
| production of oncogene-specific proteins and human t-cell leukemia (lymphotropic) retrovirus (htlv-i) envelope protein in bacteria and its potential for use in human cancers and seroepidemiological surveys. | the oncogenes coding for the harvey murine sarcoma virus p21ras protein as well as those coding for myc, myb, and mht products were fused to the amino-terminal portion of the bacteriophage lambda cii gene on the expression vector pjl6. in addition two regions of the gene for the human t-cell leukemia virus subgroup i (htlv-i) envelope were expressed in our bacterial system. each of 11 human sera tested that had been shown to contain antibodies to htlv-i or -ii by an enzyme-linked immunosorbent a ... | 1985 | 2861893 |
| marked in vivo antiretrovirus activity of 9-(2-phosphonylmethoxyethyl)adenine, a selective anti-human immunodeficiency virus agent. | 9-(2-phosphonylmethoxyethyl)adenine (pmea) is a potent and selective inhibitor of the replication of human immunodeficiency virus (hiv) in vitro in human t-lymphocyte mt-4, h9, and ath8 cells. pmea also inhibits moloney murine sarcoma virus (mo-msv)-induced transformation of murine c3h embryo fibroblasts. moreover, pmea causes a dose-dependent suppression of tumor formation and associated mortality in mice inoculated with mo-msv. at a dose of 50 or 20 mg/kg per day pmea effected a 90-100% protec ... | 1989 | 2911579 |
| lateral diffusion of lectin receptors in fibroblast membranes as a function of cell shape. | anchorage-dependent fibroblasts respond to biochemical growth signals only when attached to and spread on a suitable substrate surface. attachment of fibroblasts initiates a cytoskeletal assembly process that results in the organization of long actin stress fibers and microtubules which may be required for transmembrane signal transduction. fibroblasts maintained in suspension, however, remain spherical with no apparent stress fibers or lengthy microtubules. because of the significant difference ... | 1989 | 2914582 |
| clonal selection by fluorescence redistribution after photobleaching (frap)--a "fast" lateral mobility fibroblast mutant (e7g1). | fluorescence redistribution after photobleaching (frap) was utilized to select a "fast" lateral mobility clone from kirsten murine sarcoma virus-transformed 3t3 (kmsv-3t3) fibroblasts. the clone, e7g1, demonstrated a lateral mobility for membrane wheat germ agglutinin (wga) and succinylated concanavalin a (scon a) receptors of (2.1 +/- 1.6) x 10(-9) cm2/s and (2.7 +/- 2.3) x 10(-9) cm2/s, respectively. these mobilities were approximately equivalent to phospholipid mobility (2.8 +/- 1.9 x 10(-9) ... | 1989 | 2914583 |
| biochemical localization of the transformation-sensitive 52 kda (p52) protein to the substratum contact regions of cultured rat fibroblasts. butyrate induction, characterization, and quantification of p52 in v-ras transformed cells. | a 52 kda protein (p52) was identified, using differential extraction and electrophoretic criteria, as a major extracellular and substrate-associated component of normal rat kidney (nrk) fibroblasts. cells transformed with kirsten murine sarcoma virus (knrk cells) did not express p52 constitutively, but were inducible for both p52 production and its substrate association during culture in sodium butyrate (nab)-supplemented growth medium. comparative analysis of the relative molecular mass, subcel ... | 1989 | 2920008 |
| the flavonoid tangeretin inhibits invasion of mo4 mouse cells into embryonic chick heart in vitro. | tangeretin, a flavonoid from citrus plants, was found to inhibit the invasion of mo4 cells (kirsten murine sarcoma virus transformed fetal mouse cells) into embryonic chick heart fragments in vitro. the flavonoid appeared to be chemically stable in tissue culture medium, and the anti-invasive effect was reversible on omission of the molecule from the medium. unlike (+)-catechin, another anti-invasive flavonoid, tangeretin bound poorly to extracellular matrix. it did not alter fucosylated surface ... | 1989 | 2924447 |
| functions of the mos oncogene family and associated gene products. | the mos oncogene present in moloney murine sarcoma virus is one of the oldest known oncogenes, yet the identification of its biochemical function both in transformation and as a cellular proto-oncogene has been elusive. only recently have low levels of c-mos transcripts been detected in a specific group of mouse tissues. the c-mos gene is implicated in tumorigenicity by its activation by the insertion of the intracisternal a particle genome in a mouse plasmacytoma. the murine c-mos gene is capab ... | 1986 | 2946405 |
| functional characterization of murine cell lines expressing high, intermediate, or negative levels of surface receptors for interferon-gamma. | using radioiodinated murine interferon-gamma (ifn-gamma), various cell lines were analyzed for their capacity to bind ifn-gamma and to respond to its biological activity as measured by activation of the 2',5'-oligoadenylate (2-5a) synthetase, induction of the antiviral activity, and inhibition of [3h]thymidine uptake. a t-cell lymphoma, el-4, was found to express relatively high number of specific membrane receptors for ifn-gamma (60,000/cell) with a dissociation constant of around 9 x 10(-10) m ... | 1988 | 2970510 |
| coordinate regulation of the levels of type iii and type i collagen mrna in most but not all mouse fibroblasts. | a mouse genomic clone was isolated by cross-hybridization with a dna fragment which codes for the nh2-propeptide of chick alpha1(iii) collagen. the region of cross-hybridization within the mouse clone was localized, its sequence determined, and an exon coding for the nh2-propeptide of mouse alpha1(iii) collagen was identified. this dna fragment hybridizes to an rna species of approximately 5300 nucleotides, slightly larger than the major alpha2(i) collagen rna species. the mouse type iii collage ... | 1985 | 2981217 |
| analysis of viral and somatic activations of the cha-ras gene. | the activation of the cha-ras oncogene in the ej/t24 bladder carcinoma cell line was compared with the activation of the same gene in the rat-derived harvey murine sarcoma virus. the results indicate that, like the human oncogene, the harvey murine sarcoma virus-borne ras gene owes its oncogenic capacity to point mutations in coding sequences rather than to the alteration in transcriptional control that occurred when the formerly cellular ras sequences were acquired by the virus. the viral gene ... | 1985 | 2981345 |
| evidence for multiple steps in neoplastic transformation of normal and preneoplastic syrian hamster embryo cells following transfection with harvey murine sarcoma virus oncogene (v-ha-ras). | neoplastic development of syrian hamster embryo (she) cells in culture is a multistep process in which intermediate or preneoplastic cells can be identified and isolated. in an attempt to further characterize normal and preneoplastic cells, we have compared their susceptibilities to neoplastic transformation following transfection with cloned dna of the oncogenic virus, harvey murine sarcoma virus (hamsv). normal she cells, which are stably nontumorigenic when injected in nude mice, are competen ... | 1985 | 2981612 |
| further characterization of the in vitro products generated by proteolytic cleavage of gazdar murine sarcoma virus p65gag. | in vitro proteolytic cleavage of the gazdar murine sarcoma virus (gz-musv) p65gag polypeptide (gz-p65gag) was facilitated by detergent-disrupted moloney murine leukaemia virus (mo-mulv). incubation of radioactively labelled gz-p65gag in the presence of unlabelled mo-mulv under optimal conditions resulted in the cleavage of gz-p65gag to proteins of 40000 (p40) and 25000 (p25) mr. p40 and p25 appeared to be similar in both mobility and antigenicity to mo-mulv intermediates, pr40gag and pr25gag, pr ... | 1985 | 2981963 |
| temperature-sensitive viral rna expression in moloney murine sarcoma virus ts110-infected cells. | 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-kilo ... | 1985 | 2982039 |
| murine sarcoma virus ts110 rna transcripts: origin from a single proviral dna and sequence of the gag-mos junctions in both the precursor and spliced viral rnas. | our previous studies have argued persuasively that in murine sarcoma virus ts110 (musvts110) the gag and mos genes are fused out of frame due to a approximately 1.5-kilobase (kb) deletion of wild-type murine sarcoma virus 349 (musv-349) viral information. as a consequence of this deletion, infected cells grown at 39 degrees c appear morphologically normal, producing a 4-kb viral rna and a truncated gag gene product, p58gag. at 33 degrees c, however, musvts110-infected cells appear transformed, p ... | 1985 | 2982040 |
| nucleotide sequence analysis of the balb/c murine sarcoma virus transforming gene. | we determined the nucleotide sequence of the v-h-ras-related oncogene of balb/c murine sarcoma virus. this oncogene contains an open reading frame of 189 amino acids that initiates and terminates entirely within the mouse cell-derived ras sequence. the protein encoded by this open reading frame matches the sequence predicted for the t24 human bladder carcinoma oncogene product, p21, in all but two positions. the presence of a lysine residue in position 12 of balb/c murine sarcoma virus p21 likel ... | 1985 | 2983103 |
| thyroid hormone modulation of transformation induced by kirsten murine sarcoma virus. | we have investigated the effect of triiodothyronine (t3) on the transformation of normal rat kidney (nrk) cells by the kirsten strain of murine sarcoma virus (ki-msv). when nrk cells were grown and infected with ki-msv in medium lacking t3, the yield of transformed foci was about one-half that observed in the cultures supplemented with t3. individual foci appeared somewhat later in cells grown out in medium devoid of t3. the yield of ki-msv released from transformed nrk cells was lower when thes ... | 1985 | 2983886 |
| viral harvey ras p21 expressed in escherichia coli purifies as a binary one-to-one complex with gdp. | the ras oncogene of harvey murine sarcoma virus encodes a 21,000-dalton protein, p21, which mediates transformation. viral harvey ras p21, cloned into escherichia coli hb101 lambda/pras1, has been purified to homogeneity by a three-step procedure. the purified e. coli p21 can be bound by a monoclonal antibody to viral harvey ras p21 and has an amino acid composition consistent with that predicted from its dna sequence. purified e. coli p21 has been shown by hplc analysis on an ion-exchange colum ... | 1985 | 2984188 |
| epidermal growth factor precursor is related to the translation product of the moloney sarcoma virus oncogene mos. | murine epidermal growth factor (egf) is synthesized as part of a large precursor (pro-egf), which is thought to span the cell membrane. comparison of the published pro-egf sequence with the sequences of the translation products of viral oncogenes reveals that pro-egf is related to the translation product of mos, the oncogene of moloney murine sarcoma virus. similarity is greatest between the cooh-terminal region of v-mos (residues 317-360) and part of the cytoplasmic domain of pro-egf (residues ... | 1985 | 2984673 |
| development and analysis of a transformation-defective mutant of harvey murine sarcoma tk virus and its gene product. | the harvey murine sarcoma virus has been cloned and induces focus formation on nih 3t3 cells. recombinants of this virus have been constructed which include the thymidine kinase gene of herpes simplex virus type 1 in a downstream linkage with the p21 ras gene of harvey murine sarcoma virus. harvey murine sarcoma tk virus rescued from cells transfected with this construct is both thymidine kinase positive and focus inducing in in vitro transmission studies. the hypoxanthine-aminopterin-thymidine ... | 1985 | 2985821 |
| demonstration of t antigens on the surface of cells transformed with primate polyoma viruses. | primate polyoma virus-transformed hamster, mouse, and rat cell lines were examined by indirect immunofluorescence staining for cell surface-associated t antigens, by using a rabbit antiserum prepared against sodium dodecyl sulfate-denatured large t antigen of simian virus 40 (anti-sv40-sds-t serum). positive surface staining was shown not only on sv40-transformed cells, but also on bk and jc virus-transformed cells. in contrast, normal cells and cells transformed with mouse polyoma-, human adeno ... | 1985 | 2985939 |
| myeloid cell transformation by ras-containing murine sarcoma viruses. | balb and harvey murine sarcoma viruses contain ras transforming genes capable of altering the proliferation and differentiation of cells within the erythroid and lymphoid lineages (w. d. hankins and e. m. scolnick, cell 26:91-97, 1981; j. h. pierce and s. a. aaronson, j. exp. med. 156:873-887, 1982; e. m. scolnick et al., mol. cell. biol. 1:68-74). the present studies demonstrate hematopoietic targets of ras-containing viruses within the myeloid lineage. diffuse colonies were induced by balb or ... | 1985 | 2985965 |
| two oncogenes in avian carcinoma virus mh2: myc and mht. | the 5.2-kilobase (kb) rna genome of avian carcinoma virus mh2 has the genetic structure 5' - delta gag (0.2 kb)-mht (1.2 kb)-myc (1.4 kb)-c(0.4 kb)-poly (a) (0.2 kb)-3'. delta gag is a partial retroviral core protein, mht and myc are cell-derived mh2-specific sequences, and c is the 3'-terminal retroviral vector sequence. the following results were obtained from the complete nucleotide sequences of the mht and myc genes in mh2. (i) delta gag-mht forms a hybrid gene with a contiguous reading fram ... | 1985 | 2986522 |
| recognition of mos-related proteins with an antiserum to a peptide of the v-mos gene product. | a mos-specific antiserum was generated by injection of rabbits with a peptide predicted from the sequence of the v-mos gene of moloney murine sarcoma virus (musv) strain 124. the peptide is composed of amino acids 37-55 (cyclized at the cysteine residues) conjugated to keyhole limpet haemocyanin. this serum [anti-mos(37-55c)] specifically recognized p37mos in musv-124 acutely infected nih-3t3 cells, p85gag-mos in 6m2 cells, an nrk clone infected with the temperature-sensitive mutant (ts110) of m ... | 1985 | 2987403 |
| inhibition by retinoic acid of murine retrovirus-induced cellular transformation and tumor formation. | the effect of all-trans-retinoic acid (ra) on cellular transformation and on tumorigenicity of retrovirally transformed cells was investigated. ra treatment of nrk and nih/3t3 cells transformed by balb/c murine sarcoma virus (musv), kirsten murine sarcoma virus (k-musv), and simian sarcoma virus resulted in a significant reduction in anchorage-dependent growth of only k-musv-transformed nrk cells. a 62% reduction in cell number was observed at 10(-5) m ra. in contrast, anchorage-independent grow ... | 1985 | 2987593 |
| friend murine leukemia virus-immortalized myeloid cells are converted into tumorigenic cell lines by abelson leukemia virus. | friend murine leukemia virus (fr-mulv) is a replication-competent murine retrovirus that induces acute nonlymphocytic leukemias in nfs/n mice. fr-mulv disease is divided into two stages based on the ability of the leukemia cells to grow in culture and transplant into syngeneic mice. hematopoietic cells taken from the early stage of disease after fr-mulv infection grow as immortal myeloid cell lines in the presence of wehi-3 cell-conditioned medium (cm) or interleukin 3. these growth factor-depen ... | 1985 | 2987918 |
| rates of evolution of the retroviral oncogene of moloney murine sarcoma virus and of its cellular homologues. | a method is proposed for computing the rates of nucleotide substitution for an oncogene of a retrovirus (v-onc), its cellular homologue (c-onc), and the retrovirus genome simultaneously. the method has been applied to dna sequences of the v-mos gene of moloney murine sarcoma virus (mo-musv) and the c-mos and gag genes of mo-musv and moloney murine leukemia virus (mo-mulv). the rates of nucleotide substitution for c-mos, the gag gene, and v-mos are estimated to be 1.71 x 10(-9), 6.3 x 10(-4), and ... | 1985 | 2987967 |
| mutational analyses of the moloney murine sarcoma virus enhancer. | retroviral enhancers seem to play an integral role in determining tissue tropism. in an attempt to define the sequences essential for moloney murine sarcoma virus (mo-msv) enhancer activity, we have undertaken deletion and insertion mutational analyses of the 72-bp repeats. we demonstrate that, in contrast to simian virus 40 (sv40), the proximal 19 bp of the 72-bp unit of mo-msv are not essential for enhancer function in mouse fibroblasts. our analysis further localizes the 5' boundary of the mo ... | 1985 | 2988891 |
| use of site-specific antipeptide antibodies to perturb the serine kinase catalytic activity of p37mos. | the mos oncogene of moloney murine sarcoma virus encodes a protein of approximately 37,000 daltons (designated p37mos). we have detected a serine protein kinase activity which is closely associated with p37mos in immune complexes obtained with antibodies [anti-mos(37-55) serum] that were generated with a peptide containing amino acids 37 through 55 of the v-mos protein (s. a. maxwell and r. b. arlinghaus, virology 143:321-333, 1985). immune complexes that were derived with antibodies generated a ... | 1985 | 2991608 |
| nucleotide sequence and biochemical activities of the moloney murine sarcoma virus strain ht-1 mos gene. | the nucleotide sequence of the moloney murine sarcoma virus strain ht-1 (ht1msv) mos gene differs from that of the cellular mos gene in three positions, but these are silent changes, and the amino acid sequence of the v-mos and c-mos open reading frames are identical. we have overproduced the mos ht1msv (equivalent to c-mos) in escherichia coli under the control of phage lambda promoter (pl). the e. coli p40mos protein thus obtained was partially purified and examined for several biochemical act ... | 1985 | 2993645 |
| a mos oncogene-containing retrovirus, myeloproliferative sarcoma virus, transforms rat thyroid epithelial cells and irreversibly blocks their differentiation pattern. | differentiated, cloned rat thyroid epithelial cells (424 cells) were infected with a wild-type and a temperature-sensitive strain of the myeloproliferative variant of the moloney murine sarcoma virus. the thyroid cells were productively infected and transformed by both virus strains and displayed some of the typical properties of malignant cells, such as morphological changes, growth in soft agar, and in vivo tumorigenicity. the acquisition of the transformed phenotype by the virus-infected cell ... | 1985 | 2993656 |
| detection of a raf-related and two other transforming dna sequences in human tumors maintained in nude mice. | high molecular weight dnas prepared from a variety of human tumors maintained in nude mice were assayed for their ability to transform nih 3t3 cells. dnas from 4 of 21 tumors tested induced transformed foci in cultures of nih 3t3 cells. they were from a ewing sarcoma line, a glioblastoma line, a leiomyosarcoma line, and a lung carcinoma line. hybridization analyses of the nih 3t3 transformant dnas with a human repetitive sequence as probe revealed that four distinct transforming dna sequences we ... | 1985 | 2994056 |
| contribution of promoter to tissue-specific expression of the mouse immunoglobulin kappa gene. | the immunoglobulin kappa (kappa) gene promoter was activated by a "neutral" enhancer derived from harvey murine sarcoma virus (hamusv) in immunoglobulin-producing myeloma cells, regardless of the enhancer's orientation or position in the vector. in one fibroblast line (3t3) the immunoglobulin kappa gene promoter was completely inactive when linked to the hamusv enhancer, whereas in mouse l cells, promoter activity was observed only with the hamusv enhancer in tandem with the immunoglobulin kappa ... | 1985 | 2994213 |
| detection of the myristylated gag-raf transforming protein with raf-specific antipeptide sera. | the post-translational modifications of the gag-raf fusion proteins of the 3611 murine sarcoma virus (msv) have been examined by inhibiting glycosylation with tunicamycin and by in vivo labeling with [3h]myristic acid. the results show that p75gag-raf is myristylated but not glycosylated and that p90gag-raf is glycosylated but not myristylated (and is now termed gp90gag-raf). gp90gag-raf expression appeared to become lost during passage of the transformed cells, and consequently does not appear ... | 1985 | 2994296 |
| loss of epidermal growth factor receptors and release of transforming growth factors do not correlate with sarcoma virus-transformation in clonally-related nih/3t3-derived cell lines. | transformation of nih/3t3 cells by kirsten murine sarcoma virus (msv) caused a dramatic reduction in the number of cell-surface receptors for epidermal growth factor (egf). however, the number of egf receptors remained at a very low level in a non-tumourigenic revertant cell line isolated from the virus-transformed cells, indicating that an increase in egf receptors is not a requirement for the phenotypic reversion of kirsten msv-transformed 3t3 cells. serum-free conditioned medium from normal a ... | 1985 | 2994627 |