Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| a rat mutant cell clone showing temperature-dependent transformed phenotypes with functional expression of the src gene product. | the cellular mutant b814 isolated from a fischer rat cell line shows temperature-sensitivity of focus formation on infection with moloney murine sarcoma virus (mo-msv) and rous sarcoma virus (rsv). an rsv-transformed clone (s814-2) isolated from b814 cells shows temperature-sensitive transformed phenotypes for morphology, growth in soft agar, and glucose uptake. the expression, phosphorylation, and tyrosine kinase activity of pp60v-src in s814-2 were not affected at the nonpermissive temperature ... | 1989 | 2535907 |
| induction of effective immunity to moloney murine sarcoma virus using monoclonal anti-idiotypic antibody as immunogen. | we have isolated an anti-idiotypic mab (rs1.1.3), which recognizes an idiotope present on several igm mab specific for moloney murine leukemia virus (m-mulv)-determined cell surface ag. the binding of rs1.1.3 to idiotypic antibody could be inhibited by specific ag. intraperitoneal immunization of mice with purified rs1.1.3 antibody-induced effective immunity against moloney murine sarcoma virus challenge. a single injection of rs1.1.3 7 days before virus challenge resulted in a 27% reduction in ... | 1989 | 2536772 |
| 2'-5'-oligoadenylate synthetase gene expression in normal and murine sarcoma virus-transformed nih 3t3 cells. | mouse fibroblasts transformed by murine sarcoma virus (msv) are highly sensitive to the antiproliferative effect of interferon (ifn) (m. bakhanashvili, d. h. wreschner, and s. salzberg, cancer res. 43:1289-1294, 1983). to elucidate the mechanism leading to this ifn sensitivity, the expression of the 2'-5'-oligoadenylate synthetase (2-5a synthetase) gene, the presence of the 2-5a synthetase protein, and the level of its enzymatic activity were determined in ifn-treated and untreated cultures. nih ... | 1989 | 2536824 |
| harvey murine sarcoma virus: influences of coding and noncoding sequences on cell transformation in vitro and oncogenicity in vivo. | the rat-derived harvey murine sarcoma virus (ha-musv) contains a transduced ras oncogene activated by two missense mutations and flanked by rat retroviruslike vl30 sequences. ha-musv induces focal transformation of mouse nih 3t3 cells in vitro and tumors (fibrosarcomas and splenic erythroleukemias) in newborn mice. we have used these two assays to study the contribution of coding and noncoding viral sequences to the biological activity of ha-musv. a good correlation was found between the in vitr ... | 1989 | 2536840 |
| secretion, glycosylation, and phosphorylation of rat-specific, transformation-associated proteins in moloney murine sarcoma virus-transformed rat cells. | previously, we detected, by monoclonal antibody, three moloney murine sarcoma virus (mo-msv)-activated intracellular transformation-associated proteins (tap), (p66, p63, and p60) in several mo-msv-transformed rat cell lines (chan et al., biochem. biophys. res. commun., 134: 1223-1230, 1986) and found the release of tap into the extracellular medium with a change from three intracellular polypeptides to two extracellular polypeptides (p68 and p64) (li et al., virology, 156: 91-100, 1987). since t ... | 1989 | 2538234 |
| the kirsten murine sarcoma virus induces rat thyroid carcinomas in vivo. | the injection of a retrovirus carrying the v-ras-ki oncogene into the thyroid gland of adult fischer rats induces thyroid carcinomas when associated with a treatment of the animals with a goitrogenic agent. more than one hundred adult fischer rats have been treated with the goitrogen agent propylthiouracil in order to induce thyroid hyperplasia. twenty days after treatment, rat thyroid glands, surgically prepared, were injected with the kirsten murine sarcoma virus (kimsv). within three months m ... | 1989 | 2538791 |
| differential patterns of intracellular metabolism of 2',3'-didehydro-2',3'-dideoxythymidine and 3'-azido-2',3'-dideoxythymidine, two potent anti-human immunodeficiency virus compounds. | 3'-azido-2',3'-dideoxythymidine (azt) and 2',3'-didehydro-2',3'-dideoxythymidine (d4t) are potent and selective inhibitors of human immunodeficiency virus replication in mt-4 and ath8 cells. they are also inhibitory to the replication of murine retroviruses, i.e. moloney murine sarcoma virus-induced transformation of c3h cells. in mt-4 cells azt is readily phosphorylated to its 5'-monophosphate, while the 5'-di- and 5'-triphosphates are generated to a 200-600-fold lower extent than the 5'-monoph ... | 1989 | 2539371 |
| regulation of ifn-gamma-induced host cell mhc antigen expression by kirsten msv and mlv. i. effects on class i antigen expression. | we have reported previously that the kirsten murine sarcoma virus (ki-msv) that carries the v-ki-ras oncogene prevents c3h10t 1/2 fibroblasts from being able to respond to interferon-gamma (ifn-gamma) with the expression of the class ii major histocompatibility complex (mhc) antigen, h-2a. in this report we investigate further as to whether msv or its parent virus kirsten murine leukaemia virus (ki-mlv) is able to reduce host class i mhc antigen expression. the results demonstrate that class i e ... | 1989 | 2544513 |
| regulation of ifn-gamma-induced host cell mhc antigen expression by kirsten msv and mlv. ii. effects on class ii antigen expression. | we have reported previously that the kirsten murine sarcoma virus (ki-msv), which carries the v-ki-ras oncogene, prevents the induction of the class ii mhc antigen h-2a and reduces the induction of class i mhc antigens by interferon-gamma (ifn-gamma) on c3h10t 1/2 fibroblasts. it is here shown that the abolition by the virus of h-2a expression extends also to class ii antigen h-2e and that this is maintained for at least 7 days after ifn treatment. in addition no concentration of ifn-gamma teste ... | 1989 | 2544514 |
| potentiating effect of ribavirin on the anti-retrovirus activity of 3'-azido-2,6-diaminopurine-2',3'-dideoxyriboside in vitro and in vivo. | 3'-azido-2,6-diaminopurine-2',3'-dideoxyriboside (azdddapr) is a potent and selective inhibitor of human immunodeficiency virus (hiv) replication in vitro. it also inhibits moloney murine sarcoma virus (msv)-induced transformation of murine c3h/3t3 embryo fibroblasts. azdddapr causes a marked dose-dependent suppression of msv-induced tumor formation and mortality therewith associated in newborn mice infected with msv. combination of azdddapr with ribavirin resulted in a marked potentiation of it ... | 1989 | 2545163 |
| c-fos expression induces bone tumors in transgenic mice. | the proto-oncogene c-fos has been isolated as the cellular homolog of the v-fos gene found in the osteosarcoma inducing fbr- and fbj-murine sarcoma viruses (msv). expression of the c-fos gene in transgenic mice leads to the development of bone lesions of which about half progress to bone tumors mainly chondrosarcomas. the tumors display a strong preference for males and have a latency with a mean of 9.5 months. however, also mice without visible lesions develop bone tumors with the same sex pref ... | 1989 | 2547184 |
| oncogenicity of human n-ras oncogene and proto-oncogene introduced into retroviral vectors. | the n-ras gene is the only member of the ras family which has never been naturally transduced into a retrovirus. in order to study the in vitro and in vivo oncogenicity of n-ras and to compare its pathogenicity to that of h-ras, we have inserted an activated or a normal form of human n-ras cdna into a slightly modified harvey murine sarcoma virus-derived vector in which the h-ras p21 coding region had been deleted. the resulting constructions were transfected into nih 3t3 cells. the activated n- ... | 1989 | 2548008 |
| 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 |
| 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 |
| 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 |
| presence of a constitutive paracrine beta-interferon in v-mos-bearing nonmalignant reverted cells. | a stable nonmalignant revertant cell line was derived from moloney murine sarcoma virus-transformed balb/c cells after long-term cultivation in the presence of murine type i interferon (ifn). these cells gradually established resistance to exogenous ifn and were also seen to contain ifn-dependent proteins. the presence of an endogenous ifn was confirmed by the results of northern blot analysis and in situ hybridization with an ifn-beta probe, showing that only mrna specific for ifn-beta- could b ... | 1989 | 2521813 |
| 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 |
| 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 |
| immortalization of murine connective tissue-type mast cells at multiple stages of their differentiation by coculture of splenocytes with fibroblasts that produce kirsten sarcoma virus. | mature connective tissue mast cells (ctmc) have not been previously available as a cell line from any species. here we describe 15 novel mast cell lines (kisv-mc) that were derived by coculturing murine splenocytes with fibroblasts that produce a ki-ras-containing murine sarcoma virus. some of the kisv-mc lines are similar to ctmc in that they synthesize predominantly heparin proteoglycans, and contain up to 35 micrograms of histamine and 2.2 units of carboxypeptidase a/10(6) cells in secretory ... | 1988 | 2457591 |
| 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 |
| 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 |
| 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 |
| 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 |
| nuclear transport in 3t3 fibroblasts: effects of growth factors, transformation, and cell shape. | nucleocytoplasmic transport of fluorescent-labeled macromolecules was investigated in transformed and nontransformed 3t3 fibroblasts. insulin and epidermal growth factor enhanced transport three-fold after 1-2-h incubation with nontransformed adhering fibroblasts; no enhancement of transport was observed for spherical unattached fibroblasts. the concentration of growth factor for maximal enhancement was 3-10 nm. nuclear transport for kirsten murine sarcoma virus-transformed balb/c 3t3 fibroblast ... | 1988 | 2448310 |
| altered junctional permeability between cells transformed by v-ras, v-mos, or v-src. | junctional permeability in normal and transformed nrk cells was quantitatively assessed by microinjecting fluorescent dye into one cell of a pair, digitizing the changes of fluorescence intensity using video analysis techniques, and applying the digital values to a solution of fick's diffusion equation. we show that this approach reliably estimates the junctional permeance of a cell pair. cells that are temperature sensitive for transformation were shown to also be temperature sensitive vis-ă-vi ... | 1988 | 3056028 |
| expression and phenotypic alterations caused by an inducible transforming ras oncogene introduced into rat liver epithelial cells. | although transforming ras oncogenes have been implicated as causative factors in liver cell transformation, the exact function and phenotypic alterations generated by the expression of such transforming genes in liver epithelial cells has yet to be defined. we have utilized a retroviral vector system to deliver an inducible transforming ras gene into normal, anchorage dependent rat liver epithelial cells. the moloney murine sarcoma virus based vector is composed of a dominant selectable marker, ... | 1988 | 3060790 |
| human bronchial epithelial cells neoplastically transformed by v-ki-ras: altered response to inducers of terminal squamous differentiation. | many human bronchial adenocarcinomas have been shown to contain an activated ki-ras oncogene (rodenhuis et al., n. engl. j. med. 317 929-935, 1987). to test the hypothesis that activated ki-ras may be causally related to human bronchial carcinogenesis, v-ki-ras oncogene was transferred into an established human bronchial epithelial cell line, beas-2b, by infection with kirsten murine sarcoma virus (ki-msv) or by transfection with a plasmid containing the transforming region of ki-msv. these cell ... | 1988 | 3067190 |
| neoplastic transformation inactivates specific trans-acting factor(s) required for the expression of the thyroglobulin gene. | the expression of rat thyroglobulin gene is repressed following the transformation of rat thyroid cells with kirsten murine sarcoma virus. the expression of a reporter gene fused to the thyroglobulin promoter is down-regulated in transformed thyroid cells in transient or in stable transfection assays. dnase and exonuclease iii cleavage-protection analysis reveals that a promoter binding activity located at -60 base pairs from the transcription start site is substantially reduced in transformed t ... | 1988 | 3162304 |
| latent transformed growth-inhibiting factor in human malignant effusions. | an inhibitor of soft agar colony formation by a human breast carcinoma-derived cell line was found to be present in latent form in the majority of cytology-positive human malignant effusions. prior to dialysis, addition of human malignant effusions resulted in less than 10% alteration in efficiency of colony formation by the bt-20 human breast carcinoma cell line (mean efficiency 1 colony/4.3 cells plated at 14 days; mean colony diameter greater than 0.8 mm). after dialysis (membrane cutoff of 3 ... | 1988 | 3257164 |
| structural analysis of normal and transforming mil(raf) proteins: effect of 5'-truncation on phosphorylation in vivo or in vitro. | the phosphorylation sites of the cellular proto-oncogene product p71/73c-mil(raf) from quail and from human cells were analyzed by two-dimensional peptide mapping and compared to the sites phosphorylated in proteins encoded by three transforming alleles of c-mil(raf). these alleles all were 5'-truncated resulting from either retroviral transduction (v-mil, v-raf) or promoter insertion mutagenesis (ltr-c-raf). the normal cellular proteins each were phosphorylated in vivo on three major sites, two ... | 1988 | 3274084 |
| multi-step neoplastic transformation of normal human fibroblasts by co-60 gamma rays and ha-ras oncogenes. | as reported previously (namba et al., 1985; namba, 1985), normal human fibroblasts were transformed into immortal cells with abnormal karyotypes by co-60 gamma-ray irradiation. these immortally transformed cells (kmst-6) showed no clonability in soft agar and were not tumorigenic. however, by treatment with ha-ras oncogenes derived from a human lung carcinoma or harvey murine sarcoma virus, the kmst-6 cells acquired elevated clonability in soft agar and transplantability in nude mice. all the tu ... | 1988 | 3287150 |
| guanine nucleotide binding properties of purified v-ki-ras p21 protein produced in escherichia coli. | we have purified the v-ki-ras p21 protein by expression in escherichia coli of a plasmid encoding 189 amino acids of the kirsten murine sarcoma virus oncogene. the purified p21 (over 95%) exhibited a tenfold greater affinity for gtp (1.6 x 10(-7) m) than for gdp (1.1 x 10(-6) m). the preferential binding of v-ki-ras p21 towards gtp was attributed to the faster dissociation rate of gdp from the protein. the affinity of gdp to v-ki-ras p21 decreased with the depletion of mg2+ while that of gtp did ... | 1988 | 3135524 |
| multistep carcinogenesis of normal human fibroblasts. human fibroblasts immortalized by repeated treatment with co-60 gamma rays were transformed into tumorigenic cells with ha-ras oncogenes. | two normal mortal human fibroblast cell strains were transformed into immortal cell lines, susm-1 and kmst-6, by treatment with 4-nitroquinoline 1-oxide (4nqo) and co-60 gamma rays, respectively. these immortalized cell lines showed morphological changes of cells and remarkable chromosome aberrations, but neither of them grew in soft agar or formed tumors in nude mice. the immortal cell line, kmst-6, was then converted into neoplastic cells by treatment with harvey murine sarcoma virus (ha-msv) ... | 1988 | 3140712 |
| effect of recombinant human interleukin 2 on the growth of a balb/c sarcoma induced by moloney murine sarcoma virus. | the effect of in vivo administration of recombinant interleukin 2 (ril2) on the growth of a primary female balb/c sarcoma induced by moloney murine sarcoma virus (m-msv) was studied. although low-dose administration of (6,000 ju/mouse x 14 days) ril2 had no effect on the growth of the tumors, high-dose (15,000-80,000 ju/mouse x 14 days) intraperitoneal inoculation of ril2 induced tumor regression, dose-dependently. tumors in mice which received 80,000 ju/mouse/day of ril2 regressed completely 2 ... | 1988 | 3141331 |
| antibodies against viral proteins can be produced effectively in response to the increased uptake of alpha 2-macroglobulin:viral protein conjugate by macrophages. | we have previously shown that foreign antigens conjugated to alpha 2-macroglobulin (alpha 2m) were effectively taken up by macrophages, which was followed by a remarkable increase in the proliferation of immune t cells. we present in this report that the production of antibodies against viral proteins can also be effectively achieved when viral proteins were conjugated to alpha 2m and fed to the in vitro immune system. proteins derived from kirstein murine sarcoma virus (ki-msv) were partially p ... | 1988 | 2449204 |
| alpha, beta- and beta, gamma-methylene 5'-phosphonate derivatives of 3'-azido-2',3'-dideoxythymidine-5'-triphosphate. correlation between affinity for reverse transcriptase, susceptibility to hydrolysis by phosphodiesterases and anti-retrovirus activity. | a series of 5'-phosphorylated derivatives of 3'-azido-2',3'-dideoxythymidine (azddthd), including azddthd 5'-mono- and 5'-triphosphate, alpha, beta-methylene azddthd-5'-diphosphate, alpha,beta-methylene azddthd-5'-triphosphate, and beta,gamma-methylene azddthd-5'-triphosphate, were evaluated for their cytostatic and anti-retrovirus properties, and their inhibitory effects on the reverse transcriptases of moloney murine leukemia virus and human immunodeficiency virus. in contrast with the 5'-mono ... | 1988 | 2455521 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 5-azacytidine inhibits adipocytic conversion of human skin fibroblasts by kirsten murine sarcoma virus and dexamethasone. | transformation of human skin fibroblasts (sf) by the kirsten murine sarcoma virus (kimsv) is associated with their neodifferentiation into preadipose cells. hydrocortisone or dexamethasone (dx) promote the transformation/neodifferentiation of preadipocytes to fully differentiated adipocytes. 5-azacytidine (5-aza-cr) by itself, or together with dx, or immediately after inoculation with kimsv did not cause adipocytic conversion of human sf. addition of 5-aza-cr either before or immediately after e ... | 1987 | 2450793 |
| enhanced g2 chromatid radiosensitivity, an early stage in the neoplastic transformation of human epidermal keratinocytes in culture. | a deficiency in dna repair, manifest as enhanced chromatid radiosensitivity during the g2 phase of the cell cycle, together with a proliferative stimulus such as that provided by active oncogenes may be necessary and sufficient for the malignant neoplastic transformation of human keratinocytes in culture. normal epidermal keratinocytes established as continuous cell lines by transfection with psv3-neo or infection with adeno 12-sv40 hybrid virus developed enhanced g2 chromatid radiosensitivity a ... | 1987 | 2434215 |
| expression of the c-raf protooncogene in human hematopoietic cells and cell lines. | the murine sarcoma virus 3611 contains the transforming v-raf gene that has partial nucleotide homology with the src family of tyrosine kinase-encoding oncogenes. although this virus induces fibrosarcomas in mice, a recombinant murine retrovirus carrying both the raf and myc oncogenes induces immunoblastic lymphomas and immortalizes mouse macrophages in vitro. the present study has thus monitored the expression of c-raf in human hematopoietic cells. the results demonstrate the presence of a 3.6- ... | 1987 | 2436688 |
| temporary inhibition of moloney-murine sarcoma virus (m-msv) induced-tumours by adoptive transfer of ricin-treated t-lymphocytes. | the potential use of tumour-specific t-lymphocytes loaded with ricin in cell targeting experiments was investigated. moloney-murine sarcoma virus (m-msv)-specific t-lymphocytes, obtained in mass mixed leucocyte-tumour cell culture (mltc) and a m-msv-specific cytotoxic t-lymphocyte (ctl) clone, were incubated with 125i-labelled ricin in order to evaluate toxin uptake and release. the internalized ricin (4.5 x 10(-17) mol and 6.5 x 10(-17) mol per 10(2) mltc and ctl clone cells, respectively) was ... | 1987 | 2437947 |
| characterization of hyaluronate binding proteins isolated from 3t3 and murine sarcoma virus transformed 3t3 cells. | a hyaluronic acid binding fraction was purified from the supernatant media of both 3t3 and murine sarcoma virus (msv) transformed 3t3 cultures by hyaluronate and immunoaffinity chromatography. sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved the hyaluronate affinity-purified fraction into three major protein bands of estimated molecular weight (mr,e) 70k, 66k, and 56k which contained hyaluronate binding activity and which were termed hyaluronate binding proteins (habp). hyaluro ... | 1987 | 2440472 |
| murine retroviruses control class i major histocompatibility antigen gene expression via a trans effect at the transcriptional level. | moloney murine leukemia virus (m-mulv) and moloney murine sarcoma virus (m-msv) exert a regulatory effect on the class i genes of the murine major histocompatibility complex (mhc). we have previously shown that m-mulv infection of mouse fibroblasts results in a substantial increase in cell surface expression of h-2k, h-2d, and h-2l proteins, whereas m-msv, upon coinfection of the same cells, is apparently able to override the mulv-induced increase in h-2 expression. as a result of this modulatio ... | 1987 | 2441241 |
| changes in cellular gene expression in rat thyroid epithelial cells transformed by the kirsten murine sarcoma virus. | we have exploited a recently characterized system of rat thyroid epithelial cells transformed by the wild-type (wt) and a temperature-sensitive (ts) mutant strain of the kirsten murine sarcoma virus (ki-msv) in order to study the effects of the k-ras oncogene on the gene expression of differentiated thyroid epithelial cells. by using cdnas isolated from normal thyroid glands as probes, we were able to identify three sets of cellular sequences whose expression is influenced by the v-k-ras oncogen ... | 1987 | 2442021 |
| 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 |
| 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 |
| modification of steroidogenesis in rat adrenocortical cells transformed by kirsten murine sarcoma virus. | adrenal fibroblasts from adult rats acquire some adrenocortical parenchymal characteristics as a consequence of transformation in early passage with kirsten murine sarcoma virus. to further define the effects of kirsten murine sarcoma virus-induced transformation on the steroid enzymes of these cells, we investigated the capacity of kirsten murine sarcoma virus-transformed and untransformed adrenocortical fibroblasts to convert progesterone to c19 and c21 steroid metabolites. over 95% of metabol ... | 1987 | 3469015 |
| monoclonal igm antibodies that inhibit primary moloney murine sarcoma growth. | monoclonal igm antibodies with specificity for moloney murine sarcoma virus (m-musv)-moloney murine leukemia virus (m-mulv) from two hybridoma clones have been isolated and characterized. the monoclonal antibodies have specificity for a cytoplasmic and cell surface friend-moloney-rauscher group-specific antigen. immunoelectron microscopy revealed antibody binding to the surface of virus-expressing cells but not to the budding virus particles. treatment of m-musv-injected mice with monoclonal igm ... | 1987 | 3469466 |
| alteration of glycolipids in ras-transfected nih 3t3 cells. | glycosphingolipid alterations upon viral transformation are well documented. transformation of mouse 3t3 cells with murine sarcoma viruses results in marked decreases in the levels of gangliosides gm1 and gd1a and an increase in gangliotriaosylceramide. the transforming oncogenes of these viruses have been identified as members of the ras gene family. we analyzed nih 3t3 cells transfected with human h-, k- and n-ras oncogenes for their glycolipid composition and expression of cell surface gangli ... | 1987 | 3476926 |
| comparison of major cytoskeletons among normal human fibroblasts, immortal human fibroblasts transformed by exposure to co-60 gamma rays, and the latter cells made tumorigenic by treatment with harvey murine sarcoma virus. | immortally transformed human fibroblasts in general acquire an epithelial shape, while normal human fibroblasts demonstrate a spindle-shaped feature. in order to investigate this difference, three types of major cytoskeletal elements, namely, f-actin, tubulin, and vimentin of immortal human fibroblasts were morphologically compared with those of normal human fibroblasts. as a result, a significant difference was observed in the distribution and in the number of f-actin fibers between immortal an ... | 1987 | 3305051 |
| myosin isoform expression in rat rhabdomyosarcoma induced by moloney murine sarcoma virus. | myosin isoform expression was analyzed in experimental rhabdomyosarcoma (rms) using monoclonal antibodies (mabs) and immunofluorescence techniques. tumors induced by inoculating newborn rats with moloney murine sarcoma virus (mo-msv) were examined 30-90 days after birth. nine tumors and two lymph node metastases were studied by direct, indirect, and double immunofluorescence assays using a panel of five anti-myosin mabs. the mab bf-45 was specifically reactive with embryonic myosin heavy chain ( ... | 1987 | 3305517 |
| analysis of ras genes and linked viral sequences in rat hepatocarcinogenesis. | after long-term feeding of a choline-devoid diet to rats, the authors analyzed rask, rash, and rasn transcripts and gene structure in livers and liver tumors. they controlled their analysis by studying cell lines derived from chemically induced hepatomas. transcripts from all three genes were elevated in all tumors, but not in the livers from which they arose. the transcript elevations may represent an effect of active cell proliferation in the tumors. clone hihi-3, derived from the kirsten muri ... | 1987 | 3314528 |
| defective hla class ii expression in a regulatory mutant is partially complemented by activated ras oncogenes. | the human b-cell line rj2.2.5, derived by mutagenesis from a burkitt lymphoma cell line and selected for loss of hla class ii antigen expression, was infected with recombinant retroviruses containing either the harvey murine sarcoma virus oncogene v-ha-ras or the human neuroblastoma homolog nras. both activated ras genes partially complemented the regulatory defect in rj2.2.5 and specifically increased the expression of the dr and dq subsets of hla class ii genes. blot-hybridization analysis and ... | 1987 | 3317416 |
| defects in lens fiber differentiation are linked to c-mos overexpression in transgenic mice. | we describe three strains of transgenic mice derived by embryo microinjection of dna consisting of a long terminal repeat (ltr) of moloney murine sarcoma virus (mo-msv) linked to the murine c-mos coding sequences. southern analysis of the genomic dna of these strains suggested that in each case the transgene had integrated at a different chromosomal location. the strains were characterized by dominant changes in secondary lens fiber differentiation. shortly after birth, insufficient elongation o ... | 1987 | 3322940 |
| kinetic analysis of hydrocortisone effect on the neodifferentiation of kirsten murine sarcoma virus-transformed human skin fibroblasts to adipose cells. | here we have demonstrated that transformation of human skin fibroblasts (sf) by the kirsten murine sarcoma virus (kimsv) is associated with their neodifferentiation into preadipose cells. hydrocortisone (hc) and dexamethasone (dx) promoted the transformation/neodifferentiation of preadipocytes into mature fat cells. the effects of hc on the expression of adipocyte-containing foci (acf) and on the total number of transformed foci (ttf) present in kimsv-treated sf cultures were optimal at a concen ... | 1987 | 3442733 |
| mouse and rat cells undergo rapidly inducible changes in polypeptide secretion following infection with kirsten murine sarcoma virus. | characteristic changes in the secreted polypeptides of kirsten murine sarcoma virus (kimsv) transformed mouse and rat cell lines could be detected 48 hours after infection of phenotypically normal cells with this virus and correlated with detection of the kimsv encoded polypeptide p21. | 1987 | 3453098 |
| regulation of differential processing of mouse immunoglobulin mu heavy-chain mrna. | the switch between the synthesis of membrane-bound and secreted igm during b cell differentiation is accomplished by producing, from a single gene, two alternative forms of mu heavy-chain mrna that differ only in their 3' termini. the precursor mu rna is either polyadenylated at the first poly(a) site, for secreted mu mrna, or spliced between the c4 and m1 exons, for membrane-bound mu mrna, in a mutually exclusive manner. to elucidate the molecular mechanism of the differential processing of mou ... | 1987 | 3108856 |