Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| transcriptional "silencer" element in rat repetitive sequences associated with the rat insulin 1 gene locus. | the enhancer elements from either simian virus 40 or murine sarcoma virus activate the expression of a transfected rat insulin 1 (ri1) gene when placed within 2.0 kilobases or less of the ri1 gene cap site. inclusion of 4.0 kilobases of upstream ri1 sequence, however, results in a substantial reduction in the enhancer-dependent insulin gene expression. these observations suggested that a negative transcriptional regulatory element was present between 2.0 and 4.0 kilobases of the ri1 sequence. to ... | 1986 | 3010279 |
| retroviral mutants efficiently expressed in embryonal carcinoma cells. | the myeloproliferative sarcoma virus (mpsv) is a unique member of the moloney murine sarcoma virus family. due to mutations in the u3 region of its long terminal repeat, mpsv has an expanded host range that includes cells of the hematopoietic compartment. using a mpsv recombinant containing the gene for neomycin-resistance (neor-mpsv), we demonstrate that the host range of mpsv also includes undifferentiated f9 embryonal carcinoma cells. transfer of g418-resistance with neor-mpsv to f9 cells is ... | 1986 | 3010288 |
| dna polymorphisms indicate loss of heterozygosity for chromosome 11 of d98ah2 cells. | studies with cell hybrids of normal diploid cells fused with tumorigenic d98ah2 (d98) cells had implicated human chromosome 11 of a normal cell as carrying tumorigenicity suppressing information. the cervical carcinoma-derived d98 (hela) cells contain two copies of chromosome 11. in this study, analysis of restriction fragment length polymorphism of dna from d98 cells digested with one of nine restriction endonucleases and hybridized with five dna probes for highly polymorphic regions on the sho ... | 1986 | 3011364 |
| expression of the v-mos gene alters a mr 55,000 protein during acute infection by moloney murine sarcoma virus. | infection of the rat myoblast cell line, l6e9, with moloney murine sarcoma virus (mo-musv) clone 124, altered a cellular protein of mr 55,000 (p55) within 2 days of infection. the alteration of p55 was observed as a reduction in its steady-state level in cell extracts. the reduction of p55 correlated with the appearance of p37mos in infected cells. except for p55 and one other protein, no change was detected in the total protein pattern of infected cells compared to uninfected cells, as judged b ... | 1986 | 3012522 |
| antibodies against small nuclear ribonucleoproteins immunoprecipitate complexes containing ts110 moloney murine sarcoma virus genomic and messenger rnas. | small nuclear ribonucleoproteins (snrnps) are believed to play a role in processing premessenger rnas. in this study, snrnps were immunoprecipitated from extracts of cells infected with ts110 moloney murine sarcoma virus (ts110 momusv). both the unspliced 4.0 kb and the spliced 3.5-kb ts110 momusv specific rna species were found in the immunoprecipitates obtained with monoclonal antibody anti-sm and polyclonal anti-sm, anti-(u1) rnp and anti-la sera. although only a portion of the total ts110 rn ... | 1986 | 3012876 |
| glucocorticoid responsiveness of the transcriptional enhancer of moloney murine sarcoma virus. | the long terminal repeat of moloney murine sarcoma virus (momsv) contains an imperfect direct repeat that serves as a strong transcriptional enhancer. the strength of the momsv enhancer is strongly dependent on the presence of glucocorticoid hormone. mapping studies in combination with dnaase i footprinting experiments define the presence of glucocorticoid regulatory elements at the promoter-proximal ends of each enhancer repeat. these elements behave like inducible enhancers: their regulatory a ... | 1986 | 3013424 |
| efficient constitutive production of human ifn-gamma in chinese hamster ovary cells. | a human genomic dna segment of 5.6 kb containing the entire gene for immune interferon-gamma was fused through its 5'-untranslated region to the corresponding region of the simian virus 40 (sv40) t-antigen gene. the sv40 early promoter used contained a modified transcriptional enhancer element with a 93-bp repeat. supercoiled plasmid dna was used to transfect chinese hamster ovary (cho) cells, the selectable marker being a sv40-dihydrofolate gene construct. constitutive expression of the ifn-gam ... | 1986 | 3013545 |
| moloney murine sarcoma virus encoded p37mos expressed in yeast has protein kinase activity. | we describe the expression of the moloney murine sarcoma virus env-mos protein (p37mos) in yeast under the control of the yeast gal1 promoter. consistent with our previous results concerning the p37mos protein kinase made in virus infected mouse cells, p37mos produced in yeast possesses autophosphorylation activity in an immune complex kinase assay using anti-mos (37-35) serum. | 1986 | 3014729 |
| v-ras genes from harvey and balb murine sarcoma viruses can act as initiators of two-stage mouse skin carcinogenesis. | activated harvey murine sarcoma virus ras genes were introduced into epidermal cells in vivo by direct application of retroviruses to mouse skin. subsequent treatment with the tumor promoter 12-o-tetradecanoyl-phorbol-13-acetate (tpa) induced benign papillomas, some of which progressed to invasive carcinomas. initiation with virus was irreversible for at least 4 months, since tpa treatment after this latency period produced papillomas within 4 weeks. analysis of viral integration sites showed th ... | 1986 | 3015415 |
| temperature-sensitive splicing defect of ts110 moloney murine sarcoma virus is virus encoded. | ts110 moloney murine sarcoma virus (mo-musv)-nonproductively infected cells (6m2) have a transformed phenotype at 28 to 33 degrees c and a normal phenotype at 39 degrees c. at temperatures permissive for transformation, 6m2 cells contain p58gag produced from the 4.0-kilobase (kb) viral rna genome and p85gag-mos translated from a 3.5-kb spliced mrna. at 39 degrees c, only the 4.0-kb rna and its product p58gag are detected. two temperature-sensitive defects have been observed in ts110-infected 6m2 ... | 1986 | 3001353 |
| molecular basis underlying phenotypic revertants of moloney murine sarcoma virus musvts110. | we examined the molecular basis for phenotypic reversion in cells infected with a transformation mutant of murine sarcoma virus, musvts110. in musvts110-infected nrk cells (6m2 cells), the manifestation of the transformed phenotype at 33 degrees c and the normal phenotype at 39 degrees c is governed by thermosensitive splicing of the musvts110 primary transcript, a 4.0-kilobase (kb) rna which contains the gag and mos genes joined out of frame. at 33 degrees c, selectively, the 4.0-kb rna is proc ... | 1986 | 3001354 |
| 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 |
| keratin expression of both chemically and virally transformed human epidermal keratinocytes during the process of neoplastic conversion. | human epidermal cells, despite being 'immortalized' or 'transformed' by combinations of either oncogenic virus (sv40, adenovirus 12 or kirsten murine sarcoma virus) or chemical carcinogen (n-methyl-n'-nitro-n-nitrosoguanidine or 4-nitroquinoline-1-oxide) exhibited similar keratins (although quantitatively reduced) to that of control cells when grown in vitro. however, athymic nude mouse tumors derived from such cells exhibited suppression of the 52, 56 and 58 kd (basic type ii) keratins and a pr ... | 1986 | 2417737 |
| class ii histocompatibility antigen expression in human melanocytes transformed by harvey murine sarcoma virus (ha-msv) and kirsten msv retroviruses. | human melanocytes infected with ki-msv or ha-msv, but not amphotropic mulv, undergo a series of transformation-related changes that are characteristic of malignant melanoma. these are (a) expression of ia antigens, in particular dp, dq, and dr class ii histocompatibility gene products, (b) a transformed morphology and ability to grow in soft agar, and (c) a 5-10-fold increase in the cell surface expression of gd3 ganglioside. however, other characteristics of melanoma, such as independence from ... | 1986 | 2430046 |
| an activated harvey ras oncogene produces benign tumours on mouse epidermal tissue. | studies of the mutagenic action required for specific chemicals to produce benign or malignant tumours suggest that in mouse skin at least two genetic events occur before carcinoma formation. the isolation of an activated form of the c-rash gene from skin papillomas has provided evidence that this gene may be a target for the first mutation, which could constitute the initiating mutation in skin carcinogenesis. in vitro studies indicate that the v-rash gene of harvey murine sarcoma virus (ha-msv ... | 1986 | 2430189 |
| a syngeneic monoclonal antibody to murine meth-a sarcoma (hepss-1) recognizes heparan sulfate glycosaminoglycan (hs-gag): cell density and transformation dependent alteration in cell surface hs-gag defined by hepss-1. | we have isolated a syngeneic monoclonal antibody (hepss-1) reactive to a murine methylcholanthrene-induced fibrosarcoma, meth-a. hepss-1 also bound to a wide variety of established and fresh normal cells derived from not only mice but also other species such as human, monkey, rat, hamster, and chicken. immunoprecipitation of surface iodinated meth-a cell extract with hepss-1, as well as sepharose 4b gel chromatography of meth-a cell extract and detection of antigens recognized by hepss-1 by a sa ... | 1986 | 2431047 |
| point mutations in the u3 region of the long terminal repeat of moloney murine leukemia virus determine disease specificity of the myeloproliferative sarcoma virus. | the myeloproliferative sarcoma virus (mpsv) is made up entirely of sequences derived from the moloney murine leukemia virus (mo-mulv) and the cellular mos oncogene. as other members of the moloney murine sarcoma virus (mo-musv) family, mpsv transforms fibroblasts in vitro and causes sarcomas in vivo. in addition, however, mpsv also causes an acute myeloproliferative disease in adult mice. the mos oncogene is essential for its transforming capacity, but sequences specific to the long terminal rep ... | 1986 | 3016984 |
| detection of an intracellular transforming protein (v-ki-ras p21) using the flow activated cell sorter (facs). | the transforming protein coded for by the ki-ras oncogene, v-p21, localizes at the cytoplasmic face of the plasma membrane. a method is presented whereby the appearance of v-p21 in kirsten murine sarcoma virus-transformed cells can be detected by flow cytometry, using a monoclonal antibody to v-p21 and methods modified from immunofluorescence microscopy. the method is sufficiently sensitive to differentiate between cellular and viral p21 levels, to detect small subpopulations of virus-transforme ... | 1986 | 3490470 |
| expression of p21 ras oncoproteins in human cancers. | the expression of proteins encoded by ras oncogenes was examined in 52 fresh human tumors of 19 different types using antibodies generated to different peptide domains of ras proteins of molecular weight 21,000 (p21). proteins related to ras genes were detected in 90% of tested tumors. in 21% of tumors there were high levels of ras p21 of greater than 40% of the level in a harvey murine sarcoma virus transformed cell line. predominance of either cellular ha-ras or other ras p21s was found in 20 ... | 1986 | 3510727 |
| ouabain sensitivity is linked to ras -transformation in human hos cells. | mouse cells transformed by the retroviral oncogene v-ki- ras are significantly more sensitive to the toxic effects of 1mm ouabain than are their nontransformed counterparts. we have extended these findings to a human cell line (hos). hos cells (atcc crl 1543) are relatively resistant to treatment with 1 microm ouabain while khos cells (transformed by kirsten murine sarcoma virus) are extremely sensitive. two flat revertant cell lines isolated from the khos line and lacking the v- ras gene sequen ... | 1986 | 3458466 |
| rna polymerase specificity of mrna production and enhancer action. | to examine the rna polymerase (ec 2.7.7.6) specificity of rna maturation/utilization and transcriptional enhancement, we constructed a chimeric plasmid (ppoli-cat) in which a promoter for mouse rrna gene transcription was placed adjacent the coding sequences for chloramphenicol acetyltransferase (cat; ec 2.3.1.28). a number of other constructs, including plasmids also containing a murine sarcoma virus enhancer or lacking any natural eukaryotic promoter sequences, were also prepared. in apparent ... | 1986 | 3462718 |
| enhanced sensitivity of skin fibroblasts from neurofibromatosis patients to transformation by the kirsten murine sarcoma virus. a potential laboratory assay for individuals at risk of cancer. | the present work describes a laboratory assay for individuals predisposed to cancer within nf pedigrees. the assay is based on the association between the increased sensitivity of human skin fibroblasts to transformation by the kirsten murine sarcoma virus and predisposition to cancer in clinically affected patients and in otherwise apparently healthy individuals within nf pedigrees. the more sensitive the cells are to transformation by kimsv, the greater the probability that a person from whom ... | 1986 | 3032058 |
| multistep process of neoplastic transformation of normal human fibroblasts by 60co gamma rays and harvey sarcoma viruses. | as reported previously (namba et al., 1985), normal human fibroblasts were transformed by 60co gamma-ray irradiation into immortal cells with abnormal karyotypes. these transformed cells (kmst-6), however, showed a low cloning efficiency in soft agar and no transplantability. however, upon treatment with harvey murine sarcoma virus (ha-msv), the cells acquired elevated clonability in soft agar and transplantability in nude mice. ha-msv alone, however, did not convert normal human fibroblasts int ... | 1986 | 3949423 |
| retrovirus infection alters growth factor responses of t lymphocytes. | a murine helper/inducer t cell clone, d10.g4, has been infected with kirsten-murine sarcoma virus (kisv) pseudotyped with an amphotropic murine leukemia virus. the resultant ki-ras-expressing lines (kisv-d10) remain dependent on exogenous factors for continued growth but display distinctly different mitotic responses to certain cytokines as compared to the uninfected parent clone. unlike the parent d10.g4 cells, these kisv-d10 cells can be maintained in vitro indefinitely in the presence of reco ... | 1987 | 3033071 |
| chemically and virally transformed cells able to grow without anchorage in serum-free medium: evidence for an autocrine growth factor. | ba10-ir transformed cells, obtained by treating syrian hamster embryo fibroblasts (hef) with 7-methylbenz(a)anthracene and cultivated for a long period, are highly tumorigenic and grow in suspension as aggregates (spheroids) (levy et al., 1976). they also grow in attached form or as spheroids in serum-free (s-) synthetic medium, without insulin and transferrin, and form anchorage-independent (ai) colonies in this same, but semi-solid, medium. this exceptional phenotype was acquired stepwise, aft ... | 1987 | 3034920 |
| biologic and molecular characterization of two newly isolated ras-containing murine leukemia viruses. | a murine sarcoma virus (msv) was recovered from an (nfs x ns.c58v-1) f1 mouse which developed splenic sarcoma and erythroleukemia 6 months after inoculation with a mink cell focus-inducing murine leukemia virus (mulv) isolated from an nfs mouse infected with a wild mouse ecotropic mulv. the msv, designated ns.c58 msv-1, induced foci of transformation in mouse and rat fibroblasts, and inoculation of mice of various strains 2 weeks of age or younger resulted in erythroleukemia and sarcomatous lesi ... | 1987 | 3035212 |
| nickel-induced heritable alterations in retroviral transforming gene expression. | determination of the mutagenic effects of carcinogenic nickel compounds has been difficult because, like many metals, nickel is poorly or nonmutagenic in procaryotic mutagenicity assays. we attempted to characterize nickel-induced genetic lesions by assessing the effect of nickel chloride on the conditionally defective expression of the v-mos transforming gene in normal rat kidney cells infected with the murine sarcoma virus mutant ts110 (musvts110) retrovirus. musvts110 contains an out-of-frame ... | 1987 | 3037102 |
| rapid and selective alterations in the expression of cellular genes accompany conditional transcription of ha-v-ras in nih 3t3 cells. | hormone treatment of nih 3t3 cells that contain recombinant fusions between the mouse mammary virus long terminal repeat and the v-ras gene of harvey murine sarcoma virus results in conditional expression of the ras p21 gene product. levels of ras mrna and p21 are maximal after 2 to 4 h of hormone treatment. analysis of cellular rna by northern blotting and nuclease s1 protection assays indicates that the expression of two cellular rna species increases with kinetics similar to v-ras: v-sis-rela ... | 1987 | 3039349 |
| contingent replication assay (cra) procedure for rapid isolation of enhancers. | a rapid procedure for the isolation of functional enhancer sequences consists of the construction of a shotgun dna library in sv40-based plasmid shuttle vectors which depend on an enhancer for replication, the replication in monkey (cvi) cells of those vectors into which an enhancer sequence was inserted, the selective cleavage of unreplicated vectors by dpni and the recovery of the replicated vectors by transfection into escherichia coli. we describe conditions for the fusion of protoplasts to ... | 1987 | 3040530 |
| 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 |
| sequence and genomic structure of ras homologues dmras85d and dmras64b of drosophila melanogaster. | the ras homologues of drosophila melanogaster located at 85d and 64b on the polytene chromosome map were cloned using the ha-ras gene of harvey murine sarcoma virus as a probe. the genomic sequences of dmras85d and dmras64b were determined and shown to differ from previously published sequences. dmras85d is much more similar to the ha-ras, ki-ras, and n-ras genes than it is to either the dmras64b gene or to the ras genes of saccharomyces cerevisiae. comparison of the dmras85d genomic sequences w ... | 1987 | 3110012 |
| in vitro induction of osteosarcomalike lesion by transformation of differentiating skeletal precursor cells with fbr murine osteosarcoma virus. | this study analyzed the transforming potential of murine viruses in organ cultures of mouse fetal condylar cartilage: finkel-biskis-jinkins-murine sarcoma virus (fbj-musv) and finkel-biskis-reilly-murine sarcoma virus (fbr-musv). it was only the fbr-musv isolated from a radiation-induced osteosarcoma, that induced morphological changes as early as 24 hours following the infection. the latter manifested itself by a marked enlargement of the number of progenitor cells concomitant with an accumulat ... | 1987 | 3119176 |
| 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 |
| insulin stimulates the phosphorylation level of v-ha-ras protein in membrane fraction. | insulin was found to stimulate the phosphorylation of the 21,000-dalton protein encoded by the ras oncogene of harvey murine sarcoma virus in membrane fraction both in vivo and in vitro. when the human ras proteins expressed in e. coli were reconstituted with purified human insulin receptor, gtpase activity of normal or its mutated oncogenic ras protein was not stimulated by the addition of insulin. likewise, tyrosine kinase activity or insulin binding capacity of the receptor was not influenced ... | 1987 | 3555484 |
| lactate dehydrogenase-elevating virus induces anti-golgi apparatus antibodies. | a recently described autoantibody-inducing agent in mice was further characterized. tentatively designated agia (anti-golgi apparatus-inducing agent), this agent has previously been shown to cause antibody production against golgi apparatus (ga) antigen of cells from different vertebrate species as well as against tumour surface antigen of the moloney murine sarcoma virus-non-producer transformant sac. it was shown to possess the properties characteristic of lactate dehydrogenase-elevating virus ... | 1987 | 3598563 |
| human epidermal keratinocytes retain radiation resistance following in vitro immortalization and malignant transformation. | the radiobiology of human tumors suggests that multiple factors are involved in clinical radioresponsiveness. to date, no direct experimental evidence is available to correlate intrinsic cellular radiosensitivity with the steps of malignant transformation. we developed an in vitro multistage model of epithelial neoplasia using human epidermal keratinocytes to examine the effects of malignant transformation on radiation response. these cells were first immortalized as a result of infection with a ... | 1987 | 3659288 |
| revertants of v-fos-transformed fibroblasts have mutations in cellular genes essential for transformation by other oncogenes. | morphologic revertants of fbj murine sarcoma virus (v-fos)-transformed rat-1 fibroblasts were isolated using a novel selection procedure based on prolonged retention of rhodamine 123 within mitochondria of v-fos-transformed versus normal fibroblasts. two classes of revertants were isolated: class i revertants have sustained mutations in cellular genes, and a class ii revertant has a nonfunctional v-fos provirus. somatic-cell hybridization studies suggested that the revertant phenotype was recess ... | 1987 | 3664639 |
| effects of ouabain on nih/3t3 cells transformed with retroviral oncogenes and on human tumor cell lines. | both murine and human cell lines transformed by the v-ki-ras gene have been shown to be much more sensitive to the toxic effects of the cardiac glycoside ouabain than their respective controls. this differential toxicity has previously been used in the isolation of flat revertant clones from populations of kirsten murine sarcoma virus transformed nih/3t3 cells. here, we have undertaken a further characterization of this phenomenon in murine and human tumor cells. two different techniques, a 51cr ... | 1987 | 3679592 |
| electric field-mediated gene transfer (electroporation) into mouse friend and human k562 erythroleukemic cells. | electroporation, the technique of electric field mediated gene transfer, was evaluated as a means of introducing and expressing genes into mouse friend and human k562 erythroleukemic cells. long-term (stable) gene expression in both friend and k562 cells was measured using the recombinant plasmid homer 6, which carries the aminoglycoside phosphotransferase (aph) gene as a selectable marker under the transcriptional control of the moloney murine sarcoma virus long terminal repeat promoter/enhance ... | 1987 | 3507389 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| lipoprotein-associated oncornavirus-inactivating factor in the genus mus: effects on murine leukemia viruses of laboratory and exotic mice. | high titers of oncornavirus-inactivating factor (oif) were found previously in sera of laboratory mice. oif is highly active against mouse xenotropic and polytropic envelope recombinant murine leukemia viruses (mulvs) but not against ecotropic mulvs. of the 20 different mouse species or subspecies currently tested, that represent 4 subgenera, no oif was found in the 3 subgenera more distant to the laboratory mouse. in the subgenus mus, 7 of the 8 most distant species had no oif, whereas all the ... | 1987 | 3026614 |
| germ line integration of a murine leukemia provirus into a retroviruslike sequence. | nucleotide sequence analysis of the cellular sequences flanking the integrated ecotropic (mouse-infectious) murine leukemia provirus of balb/c mice indicated that the murine leukemia provirus is integrated in opposing transcriptional orientation within a solo long terminal repeat (ltr) of the vl30 family of endogenous retrovirus-related sequences. to quantify the effect of this integration event on the ability of the ecotropic provirus to be expressed, we constructed recombinant molecules that c ... | 1987 | 3027396 |
| the interaction of retrovirus and chemical carcinogen in experimental colon carcinogenesis. | the isolation and characterization of oncogenes from human colon cancer and the recognition of their homology with the ras gene of the harvey and kirsten strain of murine sarcoma virus (msv) led us to investigate the effect of exogenous msv on 1,2 dimethylhydrazine (dmh)-induced colon carcinoma in rats. dmh, 20 mg base/kg, was injected weekly for 10 weeks into sprague-dawley rats. the moloney murine sarcoma virus (msv-m) was injected (200 focus-forming units) intraperitoneally into 15 rats 48 ho ... | 1987 | 3027910 |
| monoclonal antibody study of the subcellular localization and dna-stimulating activity of murine sarcoma virus-activated transformation-associated proteins. | previously, we reported the monoclonal antibody detection of transformation-associated proteins (tap) in ts110 murine sarcoma virus-transformed normal rat kidney (6m2) cells (chan et al., 1986). in this study, we used the same monoclonal antibody to investigate the subcellular localization, the fate and the mitogenic activity of tap, as well as the correlationship between tap synthesis and the expression of transformation properties of 6m2 cells. it was found that tap were localized in the cytop ... | 1987 | 3027972 |
| increased adenylate cyclase activity in rat thyroid epithelial cells expressing viral ras genes. | the activity of the adenylate cyclase catalytic subunit is higher in harvey and kirsten murine sarcoma viruses-infected thyroid epithelial cells than in uninfected control cells either in the presence of mg2+ alone or following stimulation by mn2+ or forskolin. the higher activity is associated with an increased camp cellular content. the gpp(nh)p and f- anion are more effective positive modulators in the control than in the virus infected cells: these results exclude therefore that the ras p21 ... | 1987 | 3028415 |
| at least two nuclear proteins bind specifically to the rous sarcoma virus long terminal repeat enhancer. | we used the sensitive gel electrophoresis dna-binding assay and dnase i footprinting to detect at least two protein factors (efi and efii) that bound specifically to the rous sarcoma virus (rsv) enhancer in vitro. these factors were differentially extracted from quail cell nuclei, recognized different nucleotide sequences in the u3 region of the rsv long terminal repeat, and appeared to bind preferentially to opposite dna strands as monitored by the dnase i protection assay. the efi- and efii-pr ... | 1987 | 3029568 |
| functional activity in vivo of effector t cell populations. iii. protection against moloney murine sarcoma virus (m-msv)-induced tumors in t cell deficient mice by the adoptive transfer of a m-msv-specific cytolytic t lymphocyte clone. | the functional activity of moloney murine sarcoma virus (m-msv)-specific t lymphocytes in vivo was assayed by the i.v. injection of virus-specific t lymphocytes into t cell-deficient "b mice". virus-specific t lymphocytes generated in mixed lymphocyte tumor cell cultures were transferred i.v. into syngeneic "b mice" injected simultaneously at a distant site with the virus. these experiments indicated that a low dose (1 x 10(6) cultured cells) of infused lymphocytes can afford protection. to defi ... | 1987 | 3030766 |
| structure and expression of mos sequences in spontaneous and moloney murine sarcoma virus-induced yolk sac carcinomas in rats. | facilitation of yolk-sac carcinoma (ysca) development in fetectomized rats by the moloney murine sarcoma virus/murine leukemia virus (mo-msv/mlv) complex was found to be closely associated with the presence of mo-msv sequences in the genomes of the ysca cells. the virus-induced yscas consisted of cells of mono- or oligoclonal origin which always contained in their genomes at least i randomly integrated mo-msv provirus. in yscas which developed in the absence of virus, no rearrangement or amplifi ... | 1987 | 3030942 |
| 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 |
| 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 |
| 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 |
| amplification and rearrangement of the kirsten ras oncogene in virus-transformed balb/c 3t3 cells during malignant tumor progression. | analyses of the cellular and viral kirsten ras genes (c-ki-ras and v-ki-ras, respectively) during malignant tumor progression were performed by using kirsten murine sarcoma virus-transformed balb/c 3t3 cells that harbor a replication-defective provirus. after injection into athymic nude mice by four different routes, primary tumors and secondary lung metastases were isolated, adapted to in vitro growth, and analyzed for dna levels and mrna expression of both genes for comparison with the origina ... | 1987 | 3474646 |
| continuing rearrangement of immunoglobulin and t-cell receptor genes in a ha-ras-transformed lymphoid progenitor cell line. | the arrangement of immunoglobulin genes has been examined in a series of lymphoid cell lines transformed with the harvey murine sarcoma virus. one cell line, haftl-1, expresses antigenic markers characteristic of b-lymphoid cells and undergoes frequent rearrangement at the jh locus (where j = joining and h = heavy chain) during propagation in culture. by molecular cloning and nucleotide sequence determination, these rearrangements were found to represent the earliest postulated step in heavy cha ... | 1987 | 3470759 |
| 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 |
| 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 |
| 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 |