Cloned mouse mammary tumor virus DNA is biologically active in transfected mouse cells and its expression is stimulated by glucocorticoid hormones

Buetti, Elena; Diggelmann, Heidi

doi:10.1016/0092-8674(81)90129-x

Cited by 171 publications

(77 citation statements)

References 54 publications

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“…The level of induction by DM of the MMTV promoter in gmDBP1 through gmDBP3 is considerably higher than the 5-to 15-fold increase generally reported for mouse or hamster cells, which contain integrated copies of DM-inducible genes (8,11,22,33). At least two factors control the level of induction in human cell lines: the site of integration and cell type.…”

Section: Discussionmentioning

confidence: 80%

Introduction, stable integration, and controlled expression of a chimeric adenovirus gene whose product is toxic to the recipient human cell.

Klessig¹,

Brough²,

Cleghon³

1984

Mol. Cell. Biol.

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The DNA-bindihg protein (DBP) encoded by human adenoviruses is a multifunctional polypeptide which plays a central iole in regulating the expression of the viral genes. To gain a better understanding of the relationships between the various functions provided by IBP, an extensive collection of DBP mutants is essential. To this end we have constructed several permissive human cell lines which contain and express the DBP gene at high levels to allow propagation of otherwise lethal, nonrecoverable mutants of DBP. Because DB3P is totic to human cells, cell lines were constructed by using a vector in which the DBP gene is under the control of the dexamethasone-inducible promoter of the mouse mammary tumor virus. The low basal levels of DBP synthesis in the absence of dexamethasone allows isolation and propagation of these cells. Addition of dexamethasone enhances DBP production 50-to 200-fold, and within 8 h its synthesis fromb the single integrated copy of the chimeric gene is 5 to 15% of that observed during peak DBP synthesis in infected human cells in which hundreds of copies of the DBP gene serve as templates. At the nonpermissive temperature, adenovirus mutants with ts lesions in the DBP gene replicate their DNAs, express their late genes, and form infectious viral particles in these DBP+ cell lines but not in the parental HeLa cells.A number of multifunctional proteins in euearyotes have been defined by,a combination of genetic and biochemical studies. One of the best characterized of these is the simian virus 40 (SV40) large T antigen, which exhibits separate functional domains as discerned by mapping of sets of mutations which alter one but not another of the various protein functions.The human adenovirus 72-kilodalton DNA-binding protein (DBP) also plays several independent roles during the infectious cycle of this virus. Several mutants with temperature sensitive (tsj alterations in the DBP have been indispensable in defining several of the functions of this protein. The ts alterations at the nonpermissive temperature diminish the single-strand, DNA-binding activity of the protein in vitro (52) and inhibit DNA replication in vivo (13, 47, 53) and in vitro (20). Normal turn-off of viral early genes during the late phase of the lytic cycle is also disrupted at the nonpermissive temperature in cells infected with the ts mutant (6,9,10,37,38). The DBP directly affects early gene turn-off as well as DNA replication, since inhibition of viral DNA synthesis with either drugs or ts lesions in other viral early genes does not affect early gene expression (9, 10). In addition, at the nonpermissive temperatui*, the ts mutants transform rat cells in culture with an enhanced frequency compared with wild-type (wt) virus (16,54).A second class of mutants which greatly enhance the ability of this human virus to grow in monkey cells defines yet a second set of functions of DBP (1,26,29). In monkey cells infected with wt human adenovirus, the viral early genes are properly expressed (3), and viral DNA replication occurs no...

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Section: Discussionmentioning

confidence: 80%

Introduction, stable integration, and controlled expression of a chimeric adenovirus gene whose product is toxic to the recipient human cell.

Klessig¹,

Brough²,

Cleghon³

1984

Mol. Cell. Biol.

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“…Cells were labelled with 35S-methionine (200pCiml-1) for 1 or 6h as described by Westley & Rochefort (1980) and cell extracts prepared for immunoprecipitation according to Buetti & Diggelmann (1981).…”

Section: Methodsmentioning

confidence: 99%

Oestrogenic activity of tamoxifen and its metabolites on gene regulation and cell proliferation in MCF-7 breast cancer cells

Johnson

Westley²,

May³

1989

Br J Cancer

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Summary The effects of tamoxifen, three of its in vivo metabolites and 3-hydroxytamoxifen on cellular proliferation and the induction of four oestrogen-regulated RNAs (pNR-1, pNR-2, pNR-25 and cathepsin D) have been measured in MCF-7 breast cancer cells in phenol red-free culture medium. Tamoxifen and 3-hydroxytamoxifen acted as partial oestrogens to stimulate cell growth and the levels of the pNR-2 and pNR-25 RNAs. They were full oestrogens for the induction of cathepsin D RNA and induced the pNR-l RNA above the level found in oestrogen-treated cells. N-Desmethyltamoxifen and 4-hydroxytamoxifen behaved like tamoxifen except that N-desmethyltamoxifen did not induce the pNR-2 RNA and was only a partial oestrogen for the induction of cathepsin D RNA, and 4-hydroxytamoxifen did not induce the pNR-2 or pNR-25 RNAs. In the presence of oestradiol, the four anti-oestrogens prevented the stimulation of growth and reduced (pNR-2 and pNR-25) or increased (pNR-1) the RNA levels to those present in MCF-7 cells treated with the anti-oestrogen alone. In contrast, for cathepsin D RNA levels there was a synergistic effect of the anti-oestrogens and oestradiol. The concentration at which each anti-oestrogen was effective was related to its affinity for the oestrogen receptor. Metabolite E was a full oestrogen for the induction of cell proliferation and the oestrogen-regulated RNAs. pNR-25 and pNR-2 RNA levels correlated most closely with effects on cell proliferation. These RNAs are therefore potentially the most useful for predicting the response of breast cancer patients to tamoxifen therapy.

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“…Using these techniques, investigators have introduced several eucaryotic genes into foreign cells, and their expression has been demonstrated at the nucleic acid level, protein level, or both (Mulligan et al, 1979;Wigler et al, 1979;DeRobertis and Olson, 1979;Capecchi, 1980;Grosschedl and Birnstiel, 1980;Lai et al, 1980). Furthermore, there are recent reports of regulation of gene expression in these systems (Kurtz, 1981;Buetti and Diggelmann, 1981;Hynes et al, 1981). For other genes, we anticipate that expression or regulation may be difficult to demonstrate because the appropriate cell type may not be amenable to analysis in culture, or developmental programming may be essential.…”

Section: Introductionmentioning

confidence: 99%

Somatic expression of herpes thymidine kinase in mice following injection of a fusion gene into eggs

Brinster

Chen

Trumbauer

et al. 1981

Cell

635

223

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SummaryA plasmid, designated pMK, containing the structural gene for thymidine kinase from herpes simplex virus (HSV) fused to the promoter/regulatory region of the mouse metallothionein-I gene, was injected into the pronucleus of fertilized one-cell mouse eggs; the eggs were subsequently reimplanted into the oviducts of pseudopregnant mice. The first experiment produced 19 offspring, one of which expressed high levels of HSV thymidine kinase activity in the liver and kidney. pMK DNA sequences were detected in equal amounts in several tissues of the expressing mouse as well as in three mice that did not express HSV thymidine kinase activity. In all cases, several copies of the pMK plasmid were tandemly duplicated and integrated into mouse DNA. It appears as though multiple copies of the intact plasmid were fused by homologous recombination either before or after integration at a single site in the mouse genome. The overall efficiency of obtaining somatic expression of thymidine kinase in experiments performed to date is about 10% (4/41), and twice this number have integrated pMK DNA. This procedure not only provides a means of introducing new genes into mice, but it will also be a valuable system for studying tissue-specific regulation of gene expression.

show abstract

Cloned mouse mammary tumor virus DNA is biologically active in transfected mouse cells and its expression is stimulated by glucocorticoid hormones

Cited by 171 publications

References 54 publications

Introduction, stable integration, and controlled expression of a chimeric adenovirus gene whose product is toxic to the recipient human cell.

Introduction, stable integration, and controlled expression of a chimeric adenovirus gene whose product is toxic to the recipient human cell.

Oestrogenic activity of tamoxifen and its metabolites on gene regulation and cell proliferation in MCF-7 breast cancer cells

Somatic expression of herpes thymidine kinase in mice following injection of a fusion gene into eggs

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