| 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 |
| 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 |
| 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 |
| 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 |
| definition of the human raf amino-terminal regulatory region by deletion mutagenesis. | activation of transforming potential of the cellular raf gene has uniformly been associated with the deletion of amino-terminal coding sequences. in order to determine whether 5' truncation alone could activate cellular raf, we constructed 21 human c-raf-1 cdnas with variable bal 31-generated deletions distal to a moloney murine sarcoma virus long terminal repeat and a consensus translation initiation sequence. the deletions ranged from 136 to 1,399 nucleotides of coding sequence and shortened t ... | 1989 | 2710120 |
| the block of thyroglobulin synthesis, which occurs upon transformation of rat thyroid epithelial cells, is at the transcriptional level and it is associated with methylation of the 5' flanking region of the gene. | transformation of rat thyroid epithelial cells by kirsten murine sarcoma virus results in the block of certain thyroid differentiated functions, such as synthesis and secretion of thyroglobulin. our studies, performed by a run-on assay, demonstrate that this block occurs at the transcriptional level. we also demonstrate the de novo methylation of two methylation-sensitive sites, located within the 5' end regulatory sequences of the thyroglobulin gene, in transformed cells, in the absence of any ... | 1989 | 2767151 |
| harvey-ras mediated neoplastic development in the mouse mammary gland. | the role of a harvey-ras oncogene in mammary epithelial neoplasia was examined by infecting primary cultures of normal mouse mammary epithelial cells with either the harvey murine sarcoma virus (psi 2hamsv) alone or with hamsv plus a helper virus. the biological effects of expression of the ha-ras oncogene were determined by transplanting the infected cells into gland-cleared mammary fat pads of virgin balb/c mice. expression of the ha-ras oncogene was correlated with the development of mammary ... | 1989 | 2784851 |
| 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 |
| 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 |
| 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 |
| transformation of bone marrow cells from e mu-myc transgenic mice by abelson murine leukemia virus and harvey murine sarcoma virus. | transgenic mice harboring a c-myc gene subjugated to the immunoglobulin heavy chain enhancer offer a unique opportunity to investigate whether deregulated myc expression potentiates the transformation of b lymphoid cells by other oncogenes. by assessing colony formation in semi-solid medium, we have compared the potential of bone marrow cells from e mu-myc mice and their normal littermates for transformation by harvey murine sarcoma virus and abelson murine leukemia virus. e mu-myc bone marrow y ... | 1988 | 2840624 |
| glucocorticoids facilitate the stable transformation of embryonal rat fibroblasts by a polyomavirus large tumor antigen-deficient mutant. | the addition of glucocorticoids to the growth medium could substitute for the expression of the polyomavirus large tumor antigen in the transformation of rat fibroblasts in vitro. after transfection with a large tumor antigen-deficient mutant of polyomavirus, pbc1051, high-frequency permanent transformation was observed, if the cells were grown in medium containing dexamethasone. growth of pbc1051-transfected rat fibroblasts was strictly dependent on the presence of glucocorticoids during the in ... | 1988 | 2840668 |
| skin papillomas and other neoplasms induced by murine sarcoma viruses in mid-gestation-infected mice. | during extensive investigations on the effects of oncogenic retroviruses in developing rodents, the ability of msv to mount a neoplastic response in cd-i swiss mouse embryos was determined. by infecting the animals directly in utero at selected stages of post-implantation development, we detected a peculiar reaction of the embryonal tissues to certain msvs: when mice were exposed to kimsv at mid-gestation, the newborn developed characteristic tumors, in addition to mesenchymal cell sarcomas, not ... | 1988 | 2841249 |
| harvey sarcoma virus genome contains no extensive sequences unrelated to those of other retroviruses except ras. | the harvey murine sarcoma virus genome contains two rat-derived sets of genetic information recombined with the moloney mouse leukemia virus. the rat sequences represent a ras oncogene and a rat vl30 element. the vl30 sequences have several discrete regions of similarity with retroviral sequences which were detected by searching a protein database for similarities with predicted polypeptide sequences from the vl30 regions. on the 5' side, the most similar sequences were those of feline sarcoma v ... | 1988 | 2841504 |
| influence of the deprivation of a single amino acid on cellular proliferation and survival in rat 3y1 fibroblasts and their derivatives transformed by a wide variety of agents. | we compared proliferation and survival of various syngeneic transformed cell lines under conditions of depletion of 15 amino acids in dulbecco-eagle's medium. we used a normal fibroblast line 3y1 and 22 transformed sublines of 3y1 which had been induced by one of seven transforming agents--simian virus 40, mouse polyomavirus, adenovirus type 12, e1a gene of adenovirus type 12, cdna of harvey murine sarcoma virus, rous sarcoma virus, or n-methyl-n'-nitro-n-nitrosoguanidine. unlike other untransfo ... | 1988 | 2844831 |
| cytoarchitecture of kirsten sarcoma virus-transformed rat kidney fibroblasts: butyrate-induced reorganization within the actin microfilament network. | murine sarcoma virus-transformed rat fibroblasts (knrk cells) undergo marked cytoarchitectural reorganization during in vitro exposure to sodium-n-butyrate (nab) resulting in restoration of (1) a more typical fibroblastoid morphology, (2) proper cell-to-cell orientation, and (3) substratum adherence. augmented cell spreading, involving greater than 90% of the population, was a function of culture density and time of exposure to nab (2 mm final concentration). induced cell spreading reflected a 2 ... | 1988 | 2844835 |
| serotonin as a major serum factor inducing the phospholipase c-mediated hydrolysis of phosphoinositides in normal rat kidney cells. | calf serum induced the phospholipase c-mediated hydrolysis of phosphoinositides in normal rat kidney (nrk) cells transformed by a temperature-sensitive kirsten murine sarcoma virus (tsk-nrk cells). various growth factors known to induce the phospholipase c reactions in other cell types, such as platelet-derived growth factor, fibroblast growth factor, epidermal growth factor, thrombin, vasopressin, bombesin, cholecystokinin, and prostaglandin f2 alpha, did not induce phospholipase c reactions in ... | 1988 | 2846156 |
| increased formation of unintegrated viral dna in skin fibroblasts from patients with familial polyposis coli shortly after infection with kirsten murine sarcoma virus. | skin fibroblasts from patients with familial polyposis coli (fpc) exhibit increased frequency of morphological transformation, anchorage-independent growth, and enhanced production of viral rna and viral particles after infection with murine sarcoma virus(murine leukemia virus), msv(mlv). these fpc fibroblasts form greater amounts of unintegrated viral dna as compared to normal fibroblasts during the first 4 to 24 hr after infection with kirsten msv(kimlv), suggesting that increased susceptibili ... | 1988 | 2846448 |
| cooperative transforming activities of ras, myc, and src viral oncogenes in nonestablished rat adrenocortical cells. | early-passage rat adrenocortical cells were infected with kirsten murine sarcoma virus and mmcv mouse myc virus, two retroviruses carrying the v-ki-ras and v-myc oncogenes, respectively. efficient morphological transformation required coinfection with the two viruses, was dependent on the presence of high serum concentrations, and was not immediately accompanied by growth in soft agar. the doubly infected cells coordinately acquired the capacity for anchorage- and serum-independent growth during ... | 1988 | 2846881 |
| phosphonylmethoxyethyl purine derivatives, a new class of anti-human immunodeficiency virus agents. | a study of the structure-activity relationship of a series of newly synthesized phosphonylmethoxyalkyl purine and pyrimidine derivatives revealed that several adenine derivatives substituted at the n9 position by a 2-phosphonylmethoxyethyl (pme) group inhibited human immunodeficiency virus (hiv)-induced cytopathogenicity and hiv antigen expression in vitro at concentrations significantly below the toxicity threshold for the host cells. in terms of anti-hiv potency in mt-4 cells, the pme 2,6-diam ... | 1988 | 2847636 |
| human papillomavirus type 16 cooperates with activated ras and fos oncogenes in the hormone-dependent transformation of primary mouse cells. | the effect of human papillomavirus (hpv) and activated oncogenes on the growth and morphology of primary baby mouse kidney (bmk) cells has been studied. early region dna from hpv types 16, 18, 31, and 33, but not type 6, under the transcriptional control of a heterologous, retroviral promoter cooperated with ej-ras to produce cell lines that gave rise to carcinomas in syngeneic immunocompetent animals. the same hpv constructs, when cotransfected with a plasmid containing sequences from the finke ... | 1988 | 2848240 |
| transformation/neodifferentiation of human skin fibroblasts by acute oncornaviruses and dexamethasone. | we demonstrated that the kirsten murine sarcoma virus (kimsv) and the harvey murine sarcoma virus (hamsv) converted human skin fibroblasts (hsf) into adipocytes. adipocytic conversion of hsf by kimsv and hamsv was dependent on the presence of glucocorticosteroids. the kirsten murine leukemia virus, the harvey murine sarcoma [corrected] virus and the amphotropic helper virus (ap292) were ineffective by themselves. balb murine sarcoma virus and moloney murine sarcoma virus were, to a lesser degree ... | 1988 | 2852128 |
| [the suppression of osteogenic differentiation markers in human osteosarcoma cells transformed by kirsten murine sarcoma virus]. | | 1988 | 2855077 |
| polykaryocytosis induced by amphotropic murine c-type virus (ap129) in sac-cells nonproductively transformed by moloney murine sarcoma virus (mo-msv). | nonproducer cells of stu mouse origin (sac) transformed with moloney murine sarcoma virus (mo-msv) and superinfected with the amphotropic murine c-type virus strain ap 129 unexpectedly formed polykaryocytes. the multinuclear giant cells appeared about 30 days after ap 129 infection as confirmed in three independently performed experiments. the majority of the sac-cells became involved in syncytium formation. the polykaryocytes disappeared during continued culture transfers. various cell lines ob ... | 1985 | 2859766 |
| production of oncogene-specific proteins and human t-cell leukemia (lymphotropic) retrovirus (htlv-i) envelope protein in bacteria and its potential for use in human cancers and seroepidemiological surveys. | the oncogenes coding for the harvey murine sarcoma virus p21ras protein as well as those coding for myc, myb, and mht products were fused to the amino-terminal portion of the bacteriophage lambda cii gene on the expression vector pjl6. in addition two regions of the gene for the human t-cell leukemia virus subgroup i (htlv-i) envelope were expressed in our bacterial system. each of 11 human sera tested that had been shown to contain antibodies to htlv-i or -ii by an enzyme-linked immunosorbent a ... | 1985 | 2861893 |
| marked in vivo antiretrovirus activity of 9-(2-phosphonylmethoxyethyl)adenine, a selective anti-human immunodeficiency virus agent. | 9-(2-phosphonylmethoxyethyl)adenine (pmea) is a potent and selective inhibitor of the replication of human immunodeficiency virus (hiv) in vitro in human t-lymphocyte mt-4, h9, and ath8 cells. pmea also inhibits moloney murine sarcoma virus (mo-msv)-induced transformation of murine c3h embryo fibroblasts. moreover, pmea causes a dose-dependent suppression of tumor formation and associated mortality in mice inoculated with mo-msv. at a dose of 50 or 20 mg/kg per day pmea effected a 90-100% protec ... | 1989 | 2911579 |
| biochemical localization of the transformation-sensitive 52 kda (p52) protein to the substratum contact regions of cultured rat fibroblasts. butyrate induction, characterization, and quantification of p52 in v-ras transformed cells. | a 52 kda protein (p52) was identified, using differential extraction and electrophoretic criteria, as a major extracellular and substrate-associated component of normal rat kidney (nrk) fibroblasts. cells transformed with kirsten murine sarcoma virus (knrk cells) did not express p52 constitutively, but were inducible for both p52 production and its substrate association during culture in sodium butyrate (nab)-supplemented growth medium. comparative analysis of the relative molecular mass, subcel ... | 1989 | 2920008 |
| the flavonoid tangeretin inhibits invasion of mo4 mouse cells into embryonic chick heart in vitro. | tangeretin, a flavonoid from citrus plants, was found to inhibit the invasion of mo4 cells (kirsten murine sarcoma virus transformed fetal mouse cells) into embryonic chick heart fragments in vitro. the flavonoid appeared to be chemically stable in tissue culture medium, and the anti-invasive effect was reversible on omission of the molecule from the medium. unlike (+)-catechin, another anti-invasive flavonoid, tangeretin bound poorly to extracellular matrix. it did not alter fucosylated surface ... | 1989 | 2924447 |
| functions of the mos oncogene family and associated gene products. | the mos oncogene present in moloney murine sarcoma virus is one of the oldest known oncogenes, yet the identification of its biochemical function both in transformation and as a cellular proto-oncogene has been elusive. only recently have low levels of c-mos transcripts been detected in a specific group of mouse tissues. the c-mos gene is implicated in tumorigenicity by its activation by the insertion of the intracisternal a particle genome in a mouse plasmacytoma. the murine c-mos gene is capab ... | 1986 | 2946405 |
| functional characterization of murine cell lines expressing high, intermediate, or negative levels of surface receptors for interferon-gamma. | using radioiodinated murine interferon-gamma (ifn-gamma), various cell lines were analyzed for their capacity to bind ifn-gamma and to respond to its biological activity as measured by activation of the 2',5'-oligoadenylate (2-5a) synthetase, induction of the antiviral activity, and inhibition of [3h]thymidine uptake. a t-cell lymphoma, el-4, was found to express relatively high number of specific membrane receptors for ifn-gamma (60,000/cell) with a dissociation constant of around 9 x 10(-10) m ... | 1988 | 2970510 |
| coordinate regulation of the levels of type iii and type i collagen mrna in most but not all mouse fibroblasts. | a mouse genomic clone was isolated by cross-hybridization with a dna fragment which codes for the nh2-propeptide of chick alpha1(iii) collagen. the region of cross-hybridization within the mouse clone was localized, its sequence determined, and an exon coding for the nh2-propeptide of mouse alpha1(iii) collagen was identified. this dna fragment hybridizes to an rna species of approximately 5300 nucleotides, slightly larger than the major alpha2(i) collagen rna species. the mouse type iii collage ... | 1985 | 2981217 |
| analysis of viral and somatic activations of the cha-ras gene. | the activation of the cha-ras oncogene in the ej/t24 bladder carcinoma cell line was compared with the activation of the same gene in the rat-derived harvey murine sarcoma virus. the results indicate that, like the human oncogene, the harvey murine sarcoma virus-borne ras gene owes its oncogenic capacity to point mutations in coding sequences rather than to the alteration in transcriptional control that occurred when the formerly cellular ras sequences were acquired by the virus. the viral gene ... | 1985 | 2981345 |
| evidence for multiple steps in neoplastic transformation of normal and preneoplastic syrian hamster embryo cells following transfection with harvey murine sarcoma virus oncogene (v-ha-ras). | neoplastic development of syrian hamster embryo (she) cells in culture is a multistep process in which intermediate or preneoplastic cells can be identified and isolated. in an attempt to further characterize normal and preneoplastic cells, we have compared their susceptibilities to neoplastic transformation following transfection with cloned dna of the oncogenic virus, harvey murine sarcoma virus (hamsv). normal she cells, which are stably nontumorigenic when injected in nude mice, are competen ... | 1985 | 2981612 |
| further characterization of the in vitro products generated by proteolytic cleavage of gazdar murine sarcoma virus p65gag. | in vitro proteolytic cleavage of the gazdar murine sarcoma virus (gz-musv) p65gag polypeptide (gz-p65gag) was facilitated by detergent-disrupted moloney murine leukaemia virus (mo-mulv). incubation of radioactively labelled gz-p65gag in the presence of unlabelled mo-mulv under optimal conditions resulted in the cleavage of gz-p65gag to proteins of 40000 (p40) and 25000 (p25) mr. p40 and p25 appeared to be similar in both mobility and antigenicity to mo-mulv intermediates, pr40gag and pr25gag, pr ... | 1985 | 2981963 |
| temperature-sensitive viral rna expression in moloney murine sarcoma virus ts110-infected cells. | we examined the mos-specific intracellular rna species in 6m2 cells, an nrk cell line nonproductively infected with the ts110 mutant of moloney murine sarcoma virus. these cells present a normal phenotype at 39 degrees c and a transformed phenotype at 28 or 33 degrees c, expressing two viral proteins, termed p85gag-mos and p58gag, at 28 to 33 degrees c, whereas only p58gag is expressed at 39 degrees c. it has been previously shown that 6m2 cells contain two virus-specific rna species, a 4.0-kilo ... | 1985 | 2982039 |
| murine sarcoma virus ts110 rna transcripts: origin from a single proviral dna and sequence of the gag-mos junctions in both the precursor and spliced viral rnas. | our previous studies have argued persuasively that in murine sarcoma virus ts110 (musvts110) the gag and mos genes are fused out of frame due to a approximately 1.5-kilobase (kb) deletion of wild-type murine sarcoma virus 349 (musv-349) viral information. as a consequence of this deletion, infected cells grown at 39 degrees c appear morphologically normal, producing a 4-kb viral rna and a truncated gag gene product, p58gag. at 33 degrees c, however, musvts110-infected cells appear transformed, p ... | 1985 | 2982040 |
| nucleotide sequence analysis of the balb/c murine sarcoma virus transforming gene. | we determined the nucleotide sequence of the v-h-ras-related oncogene of balb/c murine sarcoma virus. this oncogene contains an open reading frame of 189 amino acids that initiates and terminates entirely within the mouse cell-derived ras sequence. the protein encoded by this open reading frame matches the sequence predicted for the t24 human bladder carcinoma oncogene product, p21, in all but two positions. the presence of a lysine residue in position 12 of balb/c murine sarcoma virus p21 likel ... | 1985 | 2983103 |
| thyroid hormone modulation of transformation induced by kirsten murine sarcoma virus. | we have investigated the effect of triiodothyronine (t3) on the transformation of normal rat kidney (nrk) cells by the kirsten strain of murine sarcoma virus (ki-msv). when nrk cells were grown and infected with ki-msv in medium lacking t3, the yield of transformed foci was about one-half that observed in the cultures supplemented with t3. individual foci appeared somewhat later in cells grown out in medium devoid of t3. the yield of ki-msv released from transformed nrk cells was lower when thes ... | 1985 | 2983886 |
| viral harvey ras p21 expressed in escherichia coli purifies as a binary one-to-one complex with gdp. | the ras oncogene of harvey murine sarcoma virus encodes a 21,000-dalton protein, p21, which mediates transformation. viral harvey ras p21, cloned into escherichia coli hb101 lambda/pras1, has been purified to homogeneity by a three-step procedure. the purified e. coli p21 can be bound by a monoclonal antibody to viral harvey ras p21 and has an amino acid composition consistent with that predicted from its dna sequence. purified e. coli p21 has been shown by hplc analysis on an ion-exchange colum ... | 1985 | 2984188 |
| epidermal growth factor precursor is related to the translation product of the moloney sarcoma virus oncogene mos. | murine epidermal growth factor (egf) is synthesized as part of a large precursor (pro-egf), which is thought to span the cell membrane. comparison of the published pro-egf sequence with the sequences of the translation products of viral oncogenes reveals that pro-egf is related to the translation product of mos, the oncogene of moloney murine sarcoma virus. similarity is greatest between the cooh-terminal region of v-mos (residues 317-360) and part of the cytoplasmic domain of pro-egf (residues ... | 1985 | 2984673 |
| development and analysis of a transformation-defective mutant of harvey murine sarcoma tk virus and its gene product. | the harvey murine sarcoma virus has been cloned and induces focus formation on nih 3t3 cells. recombinants of this virus have been constructed which include the thymidine kinase gene of herpes simplex virus type 1 in a downstream linkage with the p21 ras gene of harvey murine sarcoma virus. harvey murine sarcoma tk virus rescued from cells transfected with this construct is both thymidine kinase positive and focus inducing in in vitro transmission studies. the hypoxanthine-aminopterin-thymidine ... | 1985 | 2985821 |
| demonstration of t antigens on the surface of cells transformed with primate polyoma viruses. | primate polyoma virus-transformed hamster, mouse, and rat cell lines were examined by indirect immunofluorescence staining for cell surface-associated t antigens, by using a rabbit antiserum prepared against sodium dodecyl sulfate-denatured large t antigen of simian virus 40 (anti-sv40-sds-t serum). positive surface staining was shown not only on sv40-transformed cells, but also on bk and jc virus-transformed cells. in contrast, normal cells and cells transformed with mouse polyoma-, human adeno ... | 1985 | 2985939 |
| two oncogenes in avian carcinoma virus mh2: myc and mht. | the 5.2-kilobase (kb) rna genome of avian carcinoma virus mh2 has the genetic structure 5' - delta gag (0.2 kb)-mht (1.2 kb)-myc (1.4 kb)-c(0.4 kb)-poly (a) (0.2 kb)-3'. delta gag is a partial retroviral core protein, mht and myc are cell-derived mh2-specific sequences, and c is the 3'-terminal retroviral vector sequence. the following results were obtained from the complete nucleotide sequences of the mht and myc genes in mh2. (i) delta gag-mht forms a hybrid gene with a contiguous reading fram ... | 1985 | 2986522 |
| recognition of mos-related proteins with an antiserum to a peptide of the v-mos gene product. | a mos-specific antiserum was generated by injection of rabbits with a peptide predicted from the sequence of the v-mos gene of moloney murine sarcoma virus (musv) strain 124. the peptide is composed of amino acids 37-55 (cyclized at the cysteine residues) conjugated to keyhole limpet haemocyanin. this serum [anti-mos(37-55c)] specifically recognized p37mos in musv-124 acutely infected nih-3t3 cells, p85gag-mos in 6m2 cells, an nrk clone infected with the temperature-sensitive mutant (ts110) of m ... | 1985 | 2987403 |
| friend murine leukemia virus-immortalized myeloid cells are converted into tumorigenic cell lines by abelson leukemia virus. | friend murine leukemia virus (fr-mulv) is a replication-competent murine retrovirus that induces acute nonlymphocytic leukemias in nfs/n mice. fr-mulv disease is divided into two stages based on the ability of the leukemia cells to grow in culture and transplant into syngeneic mice. hematopoietic cells taken from the early stage of disease after fr-mulv infection grow as immortal myeloid cell lines in the presence of wehi-3 cell-conditioned medium (cm) or interleukin 3. these growth factor-depen ... | 1985 | 2987918 |
| rates of evolution of the retroviral oncogene of moloney murine sarcoma virus and of its cellular homologues. | a method is proposed for computing the rates of nucleotide substitution for an oncogene of a retrovirus (v-onc), its cellular homologue (c-onc), and the retrovirus genome simultaneously. the method has been applied to dna sequences of the v-mos gene of moloney murine sarcoma virus (mo-musv) and the c-mos and gag genes of mo-musv and moloney murine leukemia virus (mo-mulv). the rates of nucleotide substitution for c-mos, the gag gene, and v-mos are estimated to be 1.71 x 10(-9), 6.3 x 10(-4), and ... | 1985 | 2987967 |
| mutational analyses of the moloney murine sarcoma virus enhancer. | retroviral enhancers seem to play an integral role in determining tissue tropism. in an attempt to define the sequences essential for moloney murine sarcoma virus (mo-msv) enhancer activity, we have undertaken deletion and insertion mutational analyses of the 72-bp repeats. we demonstrate that, in contrast to simian virus 40 (sv40), the proximal 19 bp of the 72-bp unit of mo-msv are not essential for enhancer function in mouse fibroblasts. our analysis further localizes the 5' boundary of the mo ... | 1985 | 2988891 |
| nucleotide sequence and biochemical activities of the moloney murine sarcoma virus strain ht-1 mos gene. | the nucleotide sequence of the moloney murine sarcoma virus strain ht-1 (ht1msv) mos gene differs from that of the cellular mos gene in three positions, but these are silent changes, and the amino acid sequence of the v-mos and c-mos open reading frames are identical. we have overproduced the mos ht1msv (equivalent to c-mos) in escherichia coli under the control of phage lambda promoter (pl). the e. coli p40mos protein thus obtained was partially purified and examined for several biochemical act ... | 1985 | 2993645 |
| a mos oncogene-containing retrovirus, myeloproliferative sarcoma virus, transforms rat thyroid epithelial cells and irreversibly blocks their differentiation pattern. | differentiated, cloned rat thyroid epithelial cells (424 cells) were infected with a wild-type and a temperature-sensitive strain of the myeloproliferative variant of the moloney murine sarcoma virus. the thyroid cells were productively infected and transformed by both virus strains and displayed some of the typical properties of malignant cells, such as morphological changes, growth in soft agar, and in vivo tumorigenicity. the acquisition of the transformed phenotype by the virus-infected cell ... | 1985 | 2993656 |
| detection of a raf-related and two other transforming dna sequences in human tumors maintained in nude mice. | high molecular weight dnas prepared from a variety of human tumors maintained in nude mice were assayed for their ability to transform nih 3t3 cells. dnas from 4 of 21 tumors tested induced transformed foci in cultures of nih 3t3 cells. they were from a ewing sarcoma line, a glioblastoma line, a leiomyosarcoma line, and a lung carcinoma line. hybridization analyses of the nih 3t3 transformant dnas with a human repetitive sequence as probe revealed that four distinct transforming dna sequences we ... | 1985 | 2994056 |
| contribution of promoter to tissue-specific expression of the mouse immunoglobulin kappa gene. | the immunoglobulin kappa (kappa) gene promoter was activated by a "neutral" enhancer derived from harvey murine sarcoma virus (hamusv) in immunoglobulin-producing myeloma cells, regardless of the enhancer's orientation or position in the vector. in one fibroblast line (3t3) the immunoglobulin kappa gene promoter was completely inactive when linked to the hamusv enhancer, whereas in mouse l cells, promoter activity was observed only with the hamusv enhancer in tandem with the immunoglobulin kappa ... | 1985 | 2994213 |
| detection of the myristylated gag-raf transforming protein with raf-specific antipeptide sera. | the post-translational modifications of the gag-raf fusion proteins of the 3611 murine sarcoma virus (msv) have been examined by inhibiting glycosylation with tunicamycin and by in vivo labeling with [3h]myristic acid. the results show that p75gag-raf is myristylated but not glycosylated and that p90gag-raf is glycosylated but not myristylated (and is now termed gp90gag-raf). gp90gag-raf expression appeared to become lost during passage of the transformed cells, and consequently does not appear ... | 1985 | 2994296 |
| loss of epidermal growth factor receptors and release of transforming growth factors do not correlate with sarcoma virus-transformation in clonally-related nih/3t3-derived cell lines. | transformation of nih/3t3 cells by kirsten murine sarcoma virus (msv) caused a dramatic reduction in the number of cell-surface receptors for epidermal growth factor (egf). however, the number of egf receptors remained at a very low level in a non-tumourigenic revertant cell line isolated from the virus-transformed cells, indicating that an increase in egf receptors is not a requirement for the phenotypic reversion of kirsten msv-transformed 3t3 cells. serum-free conditioned medium from normal a ... | 1985 | 2994627 |
| synthesis of proviral dna in inbred mouse-derived clones of cells expressing different fv-1 phenotypes. | formation of proviral dnas by b-tropic murine leukaemia viruses (mlvs) was examined in n-type and dually permissive mutant cells derived from two inbred mouse strains, ddd and g, both of which are n-type. in the n-type cells, formation of circular proviral dna was strongly suppressed relative to that of linear dna. mutation resulting in loss of the n-type fv-1 restriction resulted in efficient formation of circular dna by the previously restricted b-tropic mlv. this showed that fv-1 restriction ... | 1985 | 2995562 |
| methionine-sensitive glycolysis in transformed cells. | glycolysis in several tumor cell lines grown in tissue culture was inhibited by methionine. kirsten murine sarcoma virus-transformed rat kidney cells (k-nrk) were inhibited 60-75% by 10 mm methionine, whereas normal rat kidney (nrk-49f) cells showed little or no inhibition. inhibition of glycolysis in k-nrk cells was manifest 2-4 hr after exposure to the amino acid. glycolysis in a chemically transformed cell line of madin-darby canine kidney cells was also sensitive to methionine, but maximal i ... | 1985 | 2995983 |
| study of the 78a1 isolate of moloney murine sarcoma virus. i. molecular cloning and characterization. | the 78a1 isolate of moloney murine sarcoma virus (78a1 mo-musv) was cloned from a genomic library obtained from virus producer rat cells, in the lambda vector l47. among the recombinants hybridizing with a probe specific for the v-mos sequences, we recovered a recombinant which contained leukaemia virus (mulv) sequences and was able to transform both mouse and rat cells in transfection experiments. the cloned provirus could be rescued by both mo-mulv ecotropic and amphotropic viruses in mouse ce ... | 1985 | 2997374 |
| study of the 78a1 isolate of moloney murine sarcoma virus. ii. haematopoietic tropism and tumourigenicity. | a new isolate of moloney murine sarcoma virus (mo-musv), designated 78a1, has been molecularly cloned. the cloned genome, found to be larger than that of other known isolates of the same virus is close in size to that of the myeloproliferative sarcoma virus (mpsv), also a derivative of the original mo-musv/moloney murine leukaemia virus (mo-mulv) complex. until now, mpsv was the only mo-musv isolate known to be capable of inducing a myeloproliferative disease associated with a tumoural syndrome ... | 1985 | 2997375 |
| posttranslational processing of p21 ras proteins involves palmitylation of the c-terminal tetrapeptide containing cysteine-186. | the p21 proteins of ras oncogenes are synthesized as precursors in the cytosol. after processing, which involves acylation, the products are associated with the plasma membrane in eucaryotic cells. the p21 overproduced in escherichia coli, however, is not processed by acylation. a synthetic tetrapeptide of the p21 c terminus is used to identify the acylation site in eucaryotic p21 as cysteine-186. the same peptide of bacterial p21 is not acylated. although p21 of harvey murine sarcoma virus-tran ... | 1985 | 2997480 |
| autoregulation plus upstream positive and negative control regions associated with transcriptional activation of the mouse p1(450) gene. | 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) is known to interact with a cytosolic receptor and, in turn, activate transcription of the mouse p1(450) gene. various lengths of dna upstream of the p1(450) gene were inserted into the psv0-cat expression vector, with and without addition of the harvey murine sarcoma virus (ha-msv) 72-bp repeat enhancer element. the constructs were cotransfected with psv2-neo into mouse hepatoma wild-type cells and two variant cell lines. one variant is believed to res ... | 1985 | 2997746 |
| serine kinase activity associated with maloney murine sarcoma virus-124-encoded p37mos. | an antiserum directed against amino acid residues 37-55 [anti-mos (37-55) serum] of the predicted v-mos sequence was used to precipitate p37mos from moloney murine sarcoma virus-124 (mo-musv-124) acutely infected 3t3 cells. proteins with sizes ranging from p37mos to 43 kda (p43) were found to be phosphorylated when anti-mos (37-55) immune complexes containing p37mos were incubated with [gamma-32p]atp and mn2+. the phosphorylation of p37mos and p43 could be specifically blocked when the anti-mos ... | 1985 | 2998008 |
| presence of circulating antibodies against gag-gene mulv proteins in patients with autoimmune connective tissue disorders. | an immunoblotting procedure using viral proteins from purified murine sarcoma virus or msv-(mlv) has been developed to characterize antiviral antibodies in sera from patients with autoimmune connective tissue disorders. fifty-eight sera with anti-sm, anti-rnp, anti-ss-b (la), and other undefined specificities were found to react with several major viral polypeptide bands. most of them corresponded to gag-gene-encoded products: pr65gag, p40gag, p30, p15, p12 and p10. other bands with molecular we ... | 1985 | 2998055 |
| stage-dependent induction of prenatal tumors in mice by the kirsten and moloney strains of murine sarcoma viruses. | the moloney (momsv) and kirsten (kimsv) strains of murine sarcoma viruses are known to induce mesenchymal sarcomas upon infection of newborn rodents. to determine their activity in mouse embryos, 11- to 15-day-pregnant cd-1 mice were laparotomized, and the single implants were inoculated into the abdominal portion of the embryonal body with an average of 15 and 1500 focus-forming particles/g of body weight of the momsv and kimsv viruses, respectively. another group of less than 1-day-old pups wa ... | 1985 | 2998593 |
| human proto-oncogene c-mos maps to 8q11. | the c-mos proto-oncogene is the cellular counterpart of the viral oncogene v-mos isolated from moloney murine sarcoma virus. the c-mos gene locus has previously been assigned to human chromosome 8. by both in situ hybridization and molecular hydridization to sorted chromosome dna (using a c-mos probe) we have localized the c-mos gene to band 8q11. this regional localization is at variance with the one previously reported at 8q22 and may explain why no rearrangement of c-mos has been found in acu ... | 1985 | 3000766 |
| comparative analysis of p21 proteins from various cell types by two-dimensional gel electrophoresis. | the products of the ras gene family are related proteins at a molecular weight of 21 kda, designated p21. in the present study we used two-dimensional gel electrophoresis to compare p21 proteins from five different normal and malignant cell lines. using a known protein (3h-labeled translation initiation factor [eif-4d]) as a standard internal marker for isoelectric point (pi), we show that p21 proteins from various cells differ only slightly in molecular weight (21-24 kda) but express a wide var ... | 1985 | 3001111 |
| 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 |
| analysis of the cellular proto-oncogene mht/raf: relationship to the 5' sequences of v-mht in avian carcinoma virus mh2 and v-raf in murine sarcoma virus 3611. | the avian carcinoma virus mh2 contains a hybrid gene delta gag-mht with a contiguous open reading frame of 2682 base pairs as well as v-myc and avian helper virus-related sequences. delta gag is a partial retroviral core protein gene while v-mht and v-myc are cell-drived sequences. the v-mht sequence can be divided into two regions: the v-raf-related region at its 3' end contains 969 nucleotides which are 94% related as amino acid sequence to the onc-specific v-raf sequence of murine sarcoma vir ... | 1985 | 3002017 |
| abelson virus drives the differentiation of harvey virus-infected erythroid cells. | abelson murine leukemia virus (a-mulv) and harvey murine sarcoma virus (ha-msv) are retroviruses carrying unrelated onc genes. however, both of these viruses are capable of stimulating the growth and differentiation of erythroid precursor cells; the target cells for both appear at the same time during fetal development and follow a similar pattern throughout ontogeny. in addition, the colonies induced by each virus are morphologically similar and synthesize the adult form of hemoglobin. however, ... | 1986 | 3002634 |
| revertants of ha-musv-transformed mdck cells express reduced levels of p21 and possess a more normal phenotype. | four subclones of the originally cloned harvey murine sarcoma virus-transformed madin darby canine kidney (mdck) cells have been isolated. these subclones fall into two general classes. two subclones have a fibroblastic morphology, have lost the growth requirement for prostaglandin e1 (pge1), do not respond to glucagon or vasopressin, and, in general, appear transformed. two other subclones have epithelioid morphologies, are growth-stimulated by pge1, respond to vasopressin with an increase in i ... | 1986 | 3002821 |
| an endogenous mouse mammary tumor virus genome common in inbred mouse strains is located on chromosome 6. | we have examined ecori-restricted cellular dna from mouse-hamster somatic cell hybrids. results of this analysis show that the unit ii mouse mammary tumor virus proviral genome is located on mouse chromosome 6. restriction analysis of cellular dna from (c3h/ouj x czech ii) x czech ii backcross mice showed a strong linkage between unit ii and igk. the gene order of these markers on chromosome 6 relative to the raf and kirsten murine sarcoma virus ras-2 proto-oncogenes was established. | 1986 | 3003402 |
| monoclonal antibody detection of transformation associated protein (tap) in ts110 moloney murine sarcoma virus transformed 6m2 cells that are different from the mos gene product. | by the use of a highly specific monoclonal antibody (designated mc), we were able to detect three radiolabeled bands with molecular weights of 60,000, 63,000, and 66,000 daltons in the ts-110 moloney murine sarcoma virus mutant-transformed rat kidney cells known as 6m2. expression of transformation properties as well as these three bands in 6m2 cells was found to be temperature sensitive. therefore, mc detected factors that are apparently associated with the transformation of 6m2 cells. these fa ... | 1986 | 3004486 |
| homologous recognition of a promoter domain common to the msv ltr and the hsv tk gene. | we have partially purified, from rat liver, a nuclear protein fraction with sequence-specific affinity to a promoter domain shared by the herpesvirus tk gene and the moloney murine sarcoma virus ltr. for both promoters, the protein-binding domain occurs roughly 80 bp upstream of the mrna cap site and harbors the pentanucleotide sequence 5'-ccaat-3'. the msv ltr pentanucleotide occurs on the coding strand in an orientation pointing toward the retroviral transcription unit. the hsv tk pentanucleot ... | 1986 | 3004739 |
| oncogenic retrovirus from spontaneous murine osteomas. ii. molecular cloning and genomic characterization. | an n-ecotropic murine leukemia virus (oa mulv), originally isolated from spontaneous osteomas of strain 101 mice, was molecularly cloned. the virus induces osteomas, osteopetrosis, and malignant lymphomas in nmri mice. the cloned virus was analyzed by heteroduplex analysis, restriction enzyme mapping, and oligonucleotide mapping. the data show a very close relationship to the endogenous akv prototype virus with some differences in the gag and the env region. the nucleotide sequence of the u3 reg ... | 1986 | 3006346 |
| hydrocortisone promotes the neodifferentiation of kirsten murine sarcoma virus transformed human skin fibroblasts to adipose cells: relevance to oncogenic mechanisms. | 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) promotes the transformation/neodifferentiation of such preadipocytes into mature fat cells. the effects of hc on the expression of adipocyte-containing foci and on the total number of transformed foci present in kimsv-treated cultures appeared to be dose-dependent and was optimal at a concen ... | 1986 | 3007230 |
| an agent or agents produced by virus-transformed cells cause unregulated ruffling in untransformed cells. | knrk cells (a normal rat kidney [nrk] cell line transformed by kirsten murine sarcoma virus) in sparse culture exhibit a highly ruffled morphology, but the cause of this ruffling is unknown. in this study, we have demonstrated that the continuous, excess ruffling on knrk cells is caused by one or more soluble agents secreted by the knrk cells themselves. to do this study, an assay for ruffling responses in live cell cultures was defined, and its reproducibility was demonstrated. this assay permi ... | 1986 | 3007528 |
| cell-mediated co-action of transforming growth factors: incubation of type beta with normal rat kidney cells produces a soluble activity that prolongs the ruffling response to type alpha. | intense, continuous ruffling is a characteristic of many transformed cells, but untransformed cells ruffle intensely only briefly after exposure to growth factors. we reported previously that cells of a normal rat kidney (nrk) cell line transformed by kirsten murine sarcoma virus secrete their own ruffle-inducing agent(s) that cause sustained ruffling in either themselves or untransformed nrk cells. in the present study, we examined the roles of the transforming growth factors tgf-alpha and tgf- ... | 1986 | 3007529 |
| nucleotide sequence of exon i of the rat c-k-ras gene. | we have isolated a dna fragment containing exon i of rat cellular proto-oncogene of k-ras and sequenced the exon i. the obtained sequence was compared with that of the corresponding region in viral oncogene of kirsten strain of murine sarcoma virus (ki-msv). the results showed that the exon i sequences of cellular k-ras genes in rat and human cells could encode the same amino acid sequence, while the viral k-ras gene could code for two different amino acids corresponding to the 12th and 37th pos ... | 1986 | 3009041 |
| 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 |
| differential transformation of c3h10t1/2 cells by v-mos: sequential expression of transformation parameters. | extremely small quantities of the product of the transforming gene v-mos of moloney murine sarcoma virus are able to efficiently transform cells. recent data indicate the existence of a threshold level for v-mos transformation of nih3t3 cells. using mouse mammary tumor virus long terminal repeat sequences or hybrid promoters consisting of mouse mammary tumor virus and moloney murine sarcoma virus long terminal repeat elements to express v-mos in c3h10t1/2 cells, we established cell lines represe ... | 1985 | 3016522 |
| 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 |
| enhancer-dependent expression of the rat preproinsulin gene in bovine papillomavirus type 1 vectors. | the effect of position in a bovine papillomavirus type 1 (bpv-1) vector on foreign gene expression was assessed with the rat preproinsulin (ri1) gene. the ri1 gene was inserted at each of the bpv-1/pml2d junctions in either transcriptional orientation in derivatives of the pdbpv-1(142-6) vector which consists of the bamhi linear genome of bpv-1 dna cloned into pml2d. transformed lines of c127 cells were established and assayed for ri1 gene expression. cells containing the ri1 gene at the 3' end ... | 1985 | 3018523 |
| delineation of transcriptional control signals within the moloney murine sarcoma virus long terminal repeat. | we identified three distinct elements within the moloney murine sarcoma virus long terminal repeat that control transcription. the phenotypes of unidirectional deletion mutants of the long terminal repeat were assayed in microinjected frog oocytes and in transfected mouse fibroblasts. steady-state levels of rna bearing the same 5' terminus as the authentic moloney murine sarcoma viral transcripts were measured by primer extension in assays that included a pseudo-wild-type internal reference. mut ... | 1985 | 3018539 |
| alternate utilization of two regulatory domains within the moloney murine sarcoma virus long terminal repeat. | the moloney murine sarcoma virus long terminal repeat (ltr) harbors two distinct positive activators of transcription, namely, a distal signal and an enhancer. in this report we demonstrate that infection by herpes simplex virus (hsv) can markedly affect the utilization of these two moloney murine sarcoma virus transcription signals. we investigated the hsv-mediated trans-acting effects with two goals in mind: first, to gain insight into ltr function, and second, to probe the mechanisms used by ... | 1985 | 3018540 |
| the effect of cerulenin on the synthesis of the precursor gag polyprotein in defective murine leukemia and sarcoma virus producing cell lines. | the effect of cerulenin, an inhibitor of de novo fatty acid (and cholesterol) biosynthesis, on the synthesis of the precursor gag polyprotein, pr65gag in a defective murine leukemia virus (334c) producing murine cell line (3je) and a defective murine sarcoma virus (gazdar) producing hamster cell line (htg-2) was examined. in contrast to moloney murine leukemia virus (m-mulv) producing cell lines (mjd-54, clone 2) the amount of the pr65gag remaining in the presence of cerulenin (20 micrograms/ml) ... | 1986 | 3019002 |
| modulation by normal serum factors of kirsten murine sarcoma virus-induced transformation in adult rat cells infected in early passage. | adult rat adrenal cells, infected with kirsten murine sarcoma virus in early passage, transform consistently in 10% fetal bovine serum (fbs)-supplemented medium. substitution of 3% horse serum (hs) for fbs reverses early foci and delays transformation. the influence of the serum on dna synthesis, anchorage dependence, tumorigenicity, and subcellular mr 21,000 transforming protein (p21) distribution was followed from infection in passage 1 to complete transformation. in fbs, increased expression ... | 1986 | 3019533 |
| molecular cloning of the temperature-sensitive 371 kirsten murine sarcoma virus and expression in escherichia coli of the mutant and wild-type viral kirsten ras p21 proteins. | rodent fibroblasts infected with the ts371 kirsten murine sarcoma virus (kimusv) are temperature sensitive for the maintenance of transformation because of the production of an abnormal p21 protein. we cloned the ts371 kimusv provirus from the genome of a conditionally transformed nonproducer cell line, ts371 kimusv nrk clone 5 (t. y. shih, m. o. weeks, h. a. young, and e. m. scolnick, j. virol. 31:546-556, 1979). the molecularly cloned virus had 1,000-fold lower transformed focus-forming activi ... | 1986 | 3022010 |
| suppression of tumor growth by senescence in virally transformed human fibroblasts. | normal human cells whether embryonic, neonatal, or adult are resistant to experimentally induced tumorigenesis in contrast to rodent or chicken cells. we showed previously that neither transformation with simian virus 40 dna nor transfection with human mutant hras dna immortalized fs-2 cells (diploid, neonatal human fibroblasts). further, tumorigenicity was not induced, despite expression of the respective transforming gene products tumor (t) antigen or p21. here we describe treatment of fs-2 an ... | 1986 | 3022300 |
| the effect of viral transformation on prostaglandin production depends on cell type. | the role of prostaglandins in cellular differentiation and transformation has been widely studied. we have found previously that prostaglandin e2 production was greatly diminished in dog kidney cells (mdck) after transformation by harvey murine sarcoma virus. in the present study, we have shown that viral transformation can have differing effects in the ability to modify the production of prostaglandin in cultured cells. for example, the prostaglandin e2 production in rat kidney cells (nrk) is d ... | 1986 | 3022469 |
| altered cellular functions in a pc-12 cell clone chronically infected with retrovirus. | we characterized retrovirus-induced changes in pc-12 cell function and neuronal differentiation. pc-12 cells were infected with a neurotropic retrovirus (temperature-sensitive moloney murine leukemia virus, mutant ba-1). we isolated a cell clone from this infected culture that displayed altered response to nerve growth factor; increased choline acetyltransferase activity; and decreased basal and nerve growth factor-stimulated acetylcholinesterase activity. in addition, kirsten murine sarcoma vir ... | 1986 | 3022728 |
| assignment of ras proto-oncogenes in chinese hamsters: implications for mammalian gene linkage conservation and neoplasia. | hras and kras are the cellular homologs of the oncogenic transforming genes found in the harvey strain of murine sarcoma virus and the kirsten murine sarcoma virus, respectively. phyla as diverse as insects, birds, and mammals possess distinct hras and kras sequences, suggesting that these genes are essential to metazoa. in this report, we used a clone panel of chinese hamster x mouse c11d somatic cell hybrids segregating hamster chromosomes to map those genes. southern filter hybridization anal ... | 1986 | 3022995 |
| expression of viral p21ras during acquisition of a transformed phenotype by rat adrenal cortex cells infected with kirsten murine sarcoma virus. | rat adrenal cortex cells infected with kirsten murine sarcoma virus acquire a transformed phenotype in a progressive fashion. the expression of the viral p21ras does not appear to correlate with the degree of transformation of the adrenocortical cells but rather is produced at similar levels as the culture becomes transformed. this indicates that the expression of an oncogenic form of p21ras is not of itself sufficient to completely transform rat adrenal cortex cells. | 1986 | 3023835 |