Induction kinetics of mutations at two genetic loci, DNA damage and repair in CHO cells after different exposure times to N-ethyl-N-nitrosourea.


:Ouabain resistance (ouar) and 6-thioguanine resistance (6-TGr) mutation frequencies were measured in Chinese hamster ovary cells after treatment with N-ethyl-N-nitrosourea (ENU) for varying periods of time. Maximal mutation frequency at the Na+/K+ ATPase gene locus (ouar mutations) was attained within 5 min of exposure, whereas the mutation frequency at the hypoxanthine guanine phosphoribosyltransferase locus (6-TGr mutations) continued to increase up to 60 min, following the theoretical curve for exponential decay of ENU with time. Detection of DNA single strand breaks (ssb) by alkaline elution showed that maximal levels were attained within 5 min of treatment with ENU. Fast repair of DNA ssb occurred early after exposure (greater than 50% repair within 10 min). Analysis of DNA ethylation products by h.p.l.c. showed initially rapid removal of O2-ethylcytosine (25% in the first hour), slow removal of 7-ethylguanine, 3-ethyladenine and 3-ethylguanine and no removal at all of O6-ethylguanine, O4-ethylthymine and ethylphosphotriesters. These time-course studies reveal different target gene responses in the fixation of DNA damage into mutations.






Dogliotti E,Vitelli A,Terlizzese M,Di Muccio A,Calcagnile A,Saffiotti U,Bignami M




Has Abstract


1987-01-01 00:00:00












  • The role of haplotype in 15q25.1 locus in lung cancer risk: results of scanning chromosome 15.

    abstract::The role of haplotypes and the interaction of haplotypes and smoking in lung cancer risk have not been well characterized. We analyzed data from an Italian population-based, case-control study with 1815 lung cancer patients and 1959 healthy controls in discovery, and performed a validation using a case-control study w...


    pub_type: 杂志文章


    authors: Ji X,Gui J,Han Y,Brennan P,Li Y,McKay J,Caporaso NE,Bertazzi PA,Landi MT,Amos CI

    更新日期:2015-11-01 00:00:00

  • Comparison of epidermal protein kinase C activity, ornithine decarboxylase induction and DNA synthesis stimulated by TPA or dioctanoylglycerol in mouse strains with differing susceptibility to TPA-induced tumor promotion.

    abstract::The purpose of this study was to examine the activity and associated kinetic parameters of epidermal protein kinase C (PKC) following stimulation by sn-1,2-dioctanoylglycerol (DIC8) or 12-O-tetradecanoylphorbol-13-acetate (TPA) and to examine the relationship between levels of epidermal PKC activity and the induction ...


    pub_type: 杂志文章


    authors: Mills KJ,Smart RC

    更新日期:1989-05-01 00:00:00

  • GDP-fucose:GM1 alpha 1----2fucosyltransferase is activated in parenchymal cells of rat liver during early stages of N-2-acetylaminofluorene induced hepatocarcinogenesis.

    abstract::Gangliosides from liver parenchymal and non-parenchymal cells were isolated from Fischer 344 rats that had been fed normal diet or a diet supplemented with 0.03% N-2-acetylaminofluorene (AAF) for 4 weeks. Gangliosides from liver cell fractions were characterized by an induction of both II3NeuAcIV3 alpha GalIV2FucGg4 a...


    pub_type: 杂志文章


    authors: Holmes EH

    更新日期:1990-01-01 00:00:00

  • Far upstream element-binding protein 1 facilitates hepatocellular carcinoma invasion and metastasis.

    abstract::Previous research suggests that far upstream element-binding protein 1 (FUBP1) plays an important role in various tumors including epatocellular carcinoma (HCC). However, the role of FUBP1 in liver cancer remains controversial, and the regulatory pathway by FUBP1 awaits to be determined. This study aims to identify th...


    pub_type: 杂志文章


    authors: Fu PY,Hu B,Ma XL,Tang WG,Yang ZF,Sun HX,Yu MC,Huang A,Hu JW,Zhou CH,Fan J,Xu Y,Zhou J

    更新日期:2020-07-14 00:00:00

  • Synergistic anti-breast cancer effect of a combined treatment with the methyl donor S-adenosyl methionine and the DNA methylation inhibitor 5-aza-2'-deoxycytidine.

    abstract::DNA-demethylating agents activate tumor suppressor genes that are silenced by DNA methylation in cancer and are therefore emerging as a novel approach to cancer therapy. 5-azacytidine (VIDAZA), the first representative of this class of drugs was approved for treatment of myelodysplastic syndromes and is currently bein...


    pub_type: 杂志文章


    authors: Chik F,Machnes Z,Szyf M

    更新日期:2014-01-01 00:00:00

  • Pre-diagnostic leukocyte mitochondrial DNA copy number and skin cancer risk.

    abstract::No previous study has examined the association between mitochondrial DNA copy number (mtCN) and skin cancer risk prospectively. We examined the associations between peripheral blood leukocytes mtCN level and the risks of skin cancers in a case-control study nested within the Nurses' Health Study of non-Hispanic White ...


    pub_type: 杂志文章


    authors: Meng S,De Vivo I,Liang L,Giovannucci E,Tang JY,Han J

    更新日期:2016-09-01 00:00:00

  • Differential effects of oltipraz on CYP1A and CYP2B in rat lung.

    abstract::Oltipraz (OPZ) is a potent chemopreventive agent against chemically-induced carcinogenesis in several animal models. It affects the expression and/or activity of xenobiotic-metabolizing enzymes and its effects are altered in the course of inflammation in liver. The present study was undertaken to analyse the effect of...


    pub_type: 杂志文章


    authors: Le Ferrec E,Ilyin G,Mahéo K,Bardiau C,Courtois A,Guillouzo A,Morel F

    更新日期:2001-01-01 00:00:00

  • Emergence of undifferentiated rat tracheal cell carcinomas, but not squamous cell carcinomas, is associated with a loss of expression of E-cadherin and of gap junction communication.

    abstract::A series of cells representing normal, non-tumorigenic cell lines, as well as differentiating neoplastic and undifferentiated neoplastic rat tracheal epithelial cell populations were evaluated for their ability to establish homologous and/or heterologous cell-cell gap junction communication in culture. Gap junction co...


    pub_type: 杂志文章


    authors: Terzaghi-Howe M,Chang GW,Popp D

    更新日期:1997-11-01 00:00:00

  • Plasma membrane calcium ATPase 4 and the remodeling of calcium homeostasis in human colon cancer cells.

    abstract::A remodeling of calcium homeostasis has been identified as a characterizing feature of some cancers. Possible consequences of this include alterations in many pivotal physiological responses including apoptosis, proliferation and gene transcription. An alteration in calcium homeostasis can occur via changes in the exp...


    pub_type: 杂志文章


    authors: Aung CS,Ye W,Plowman G,Peters AA,Monteith GR,Roberts-Thomson SJ

    更新日期:2009-11-01 00:00:00

  • DNA hypermethylation is a mechanism for loss of expression of the HLA class I genes in human esophageal squamous cell carcinomas.

    abstract::The three human leukocyte antigen (HLA) class I antigens, HLA-A, HLA-B and HLA-C, play important roles in the elimination of transformed cells by cytotoxic T cells. Frequent loss of expression of these antigens at the cell surface has been observed in many human cancers. Various mechanisms for post-transcriptional reg...


    pub_type: 杂志文章


    authors: Nie Y,Yang G,Song Y,Zhao X,So C,Liao J,Wang LD,Yang CS

    更新日期:2001-10-01 00:00:00

  • Soy processing influences growth of estrogen-dependent breast cancer tumors.

    abstract::Soy-based products consumed in Asian countries are minimally processed whereas in the USA many of the soy foods and soy ingredients are highly processed. Soy foods contain complex mixtures of bioactive compounds, which may interact with one another. The objective of this study was to evaluate the ability of various so...


    pub_type: 杂志文章


    authors: Allred CD,Allred KF,Ju YH,Goeppinger TS,Doerge DR,Helferich WG

    更新日期:2004-09-01 00:00:00

  • Ionomycin downregulates beta-catenin/Tcf signaling in colon cancer cell line.

    abstract::Functional activation of beta-catenin/Tcf signaling plays an important role in the early events in colorectal carcinogenesis. We examined the effect of ionomycin against beta-catenin/Tcf signaling in colon cancer cells. Reporter gene assay showed that ionomycin inhibited beta-catenin/Tcf signaling efficiently. In addi...


    pub_type: 杂志文章


    authors: Park CH,Hahm ER,Lee JH,Jung KC,Rhee HS,Yang CH

    更新日期:2005-11-01 00:00:00

  • Lenvatinib suppresses cancer stem-like cells in HCC by inhibiting FGFR 1-3 signaling, but not FGFR4 signaling.

    abstract::In hepatocellular carcinoma (HCC), a subset of cells defined by high CD44 and CD133 expression has been reported to possess cancer stem-like cell (CSC) characteristics and to be associated with a poor prognosis. Since the approval of the multi-kinase inhibitor, lenvatinib, for patients with unresectable HCC, two such ...


    pub_type: 杂志文章


    authors: Shigesawa T,Maehara O,Suda G,Natsuizaka M,Kimura M,Shimazaki T,Yamamoto K,Yamada R,Kitagataya T,Nakamura A,Suzuki K,Ohara M,Kawagishi N,Umemura M,Nakai M,Sho T,Morikawa K,Ogawa K,Ohnishi S,Sugiyama M,Mizokami M,

    更新日期:2020-05-25 00:00:00

  • Induction of liver cell tumours in IF mice by paracetamol.

    abstract::Groups of male and female IF strain mice were fed a diet containing either 0.5% or 1.0% paracetamol for up to 18 months. Among male mice fed the higher dose, the total liver cell tumour incidence was 87%, 21.7% developing hepatocellular carcinomas: both yields were statistically significant. The corresponding incidenc...


    pub_type: 杂志文章


    authors: Flaks A,Flaks B

    更新日期:1983-01-01 00:00:00

  • The yin and yang of nitric oxide in cancer progression.

    abstract::Nitric oxide (NO) is a short-lived, pleiotropic molecule that affects numerous critical functions in the body. Presently, there are markedly conflicting findings in the literature regarding NO and its role in carcinogenesis and tumor progression. NO has been shown to have dichotomous effects on cellular proliferation,...


    pub_type: 杂志文章,评审


    authors: Burke AJ,Sullivan FJ,Giles FJ,Glynn SA

    更新日期:2013-03-01 00:00:00

  • Over-expression of EphB3 enhances cell-cell contacts and suppresses tumor growth in HT-29 human colon cancer cells.

    abstract::Receptor tyrosine kinase EphB3 is expressed in cells in the bottom of intestinal crypts near stem cell niches. Loss of Ephb3 has recently been reported to produce invasive colorectal carcinoma in Apc(Min/+) mice and EphB-mediated compartmentalization was demonstrated to be a mechanism suppressing colorectal cancer pro...


    pub_type: 杂志文章


    authors: Chiu ST,Chang KJ,Ting CH,Shen HC,Li H,Hsieh FJ

    更新日期:2009-09-01 00:00:00

  • Formation and removal of DNA adducts in rat liver treated with N-hydroxy derivatives of 2-acetylaminofluorene, 4-acetylaminobiphenyl, and 2-acetylaminophenanthrene.

    abstract::Formation and removal of hepatic DNA adducts was studied in male Sprague-Dawley rats following single injections of two hepatocarcinogens, N-hydroxy-2-acetylaminofluorene (N-OH-AAF) and N-hydroxy-4-acetylaminobiphenyl (N-OH-AABP) and a nonhepatocarcinogen, N-hydroxy-2-acetylaminophenanthrene (N-OH-AAP) at 0.5 h, 1.5 h...


    pub_type: 杂志文章


    authors: Gupta RC,Dighe NR

    更新日期:1984-03-01 00:00:00

  • Initiation of enzyme-altered foci by the synthetic steroid cyproterone acetate in rat liver foci bioassay.

    abstract::Cyproterone acetate (CPA) is a synthetic steroid which is used in oral contraceptive and anti-androgen formulations. It has previously been classified as a tumor promoter in rat liver. Recent studies have shown that CPA induces DNA repair synthesis in isolated hepatocytes, and this implies that CPA is genotoxic. We st...


    pub_type: 杂志文章


    authors: Deml E,Schwarz LR,Oesterle D

    更新日期:1993-06-01 00:00:00

  • Exposure of Fischer 344 rats to a weak power frequency magnetic field facilitates mammary tumorigenesis in the DMBA model of breast cancer.

    abstract::The possibility that long-term exposure to relatively weak power frequency magnetic fields (MFs) emanating from the generation, transmission and use of electricity could increase the risk of breast cancer is a matter of ongoing debate. Laboratory studies using well-defined exposure conditions are useful to examine whe...


    pub_type: 杂志文章


    authors: Fedrowitz M,Löscher W

    更新日期:2008-01-01 00:00:00

  • Chemopreventive effects of early-stage and late-stage supplementation of vitamin E and selenium on esophageal carcinogenesis in rats maintained on a low vitamin E/selenium diet.

    abstract::Low vitamin E and selenium (Ve/Se) nutritional status is known to be associated with increased risk of esophageal squamous cell carcinoma (ESCC). A previous human intervention trial demonstrated that Ve/Se supplementation decreased the occurrence of esophageal cancer death among younger participants but not among olde...


    pub_type: 杂志文章


    authors: Yang H,Fang J,Jia X,Han C,Chen X,Yang CS,Li N

    更新日期:2011-03-01 00:00:00

  • Metabolic cooperation in SK-HEP-1 human hepatoma cells following treatment with benzodiazepine tranquilizers.

    abstract::The ability of three benzodiazepine tranquilizers, diazepam, oxazepam and chlordiazepoxide chlorhydrate to block metabolic cooperation between human hepatoma cells was analysed using autoradiographical monitoring. Independent tests were performed with compound concentrations varying from 1 to 50 micrograms/ml. The res...


    pub_type: 杂志文章


    authors: Rolin-Limbosch S,Moens W,Szpirer C

    更新日期:1987-07-01 00:00:00

  • Rac1 promotes diethylnitrosamine (DEN)-induced formation of liver tumors.

    abstract::To elucidate the function of the Ras-homologous GTPase Rac1 in hepatocarcinogenesis induced by diethylnitrosamine (DEN), mice lacking hepatic Rac1 expression were treated with DEN and compared to the wild-type (WT). Rac1 knock-out (KO) mice were found to have a lower tumor yield as compared to Rac1 proficient mice. Th...


    pub_type: 杂志文章


    authors: Bopp A,Wartlick F,Henninger C,Schwarz M,Kaina B,Fritz G

    更新日期:2015-03-01 00:00:00

  • The coordinate regulation of DNA synthesis and suppression of apoptosis is differentially regulated by the liver growth agents, phenobarbital and methylclofenapate.

    abstract::The coordinate regulation of DNA synthesis and suppression of apoptosis was investigated in a rat hepatocyte cell culture system which supports high level induction of DNA synthesis by the peroxisome proliferator, methylclofenapate (MCP) (Plant, N.J. et al., 1998, Carcinogenesis, 19, 925-931). The peroxisome prolifera...


    pub_type: 杂志文章


    authors: Plant NJ,Horley NJ,Dickins M,Hasmall S,Elcombe CR,Bell DR

    更新日期:1998-09-01 00:00:00

  • Induction, repair and accumulation of thymine dimers in the skin of UV-B-irradiated hairless mice.

    abstract::A monoclonal antibody specific for cyclobutane thymine dimers in DNA was used in immunofluorescence studies to detect these lesions in skin sections taken from hairless mice that had been irradiated with UV-B. The dimer-specific fluorescence in epidermal cell nuclei was quantified with fluorescence microscopy through ...


    pub_type: 杂志文章


    authors: Vink AA,Berg RJ,de Gruijl FR,Roza L,Baan RA

    更新日期:1991-05-01 00:00:00

  • Polymorphisms in genes involved in GH1 release and their association with breast cancer risk.

    abstract::The regulation of growth hormone 1 (GH1) and insulin-like-growth factor-1 (IGF-1) release is under the influence of three pituitary hormones [growth hormone releasing hormone (GHRH), ghrelin (GHRL) and somatostatin (SST)], which act in an autocrine/paracrine fashion in the breast. By binding to their respective recept...


    pub_type: 杂志文章


    authors: Wagner K,Hemminki K,Grzybowska E,Klaes R,Burwinkel B,Bugert P,Schmutzler RK,Wappenschmidt B,Butkiewicz D,Pamula J,Pekala W,Försti A

    更新日期:2006-09-01 00:00:00

  • Rapid induction of colon carcinogenesis in CYP1A-humanized mice by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and dextran sodium sulfate.

    abstract::2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant heterocyclic amine produced during the cooking of meats and fish, is suspected to be a human carcinogen. Metabolic activation of PhIP is primarily mediated by the enzyme cytochrome P450 (CYP) 1A2. Metabolism of PhIP by CYP1A2 differs considerabl...


    pub_type: 杂志文章


    authors: Cheung C,Loy S,Li GX,Liu AB,Yang CS

    更新日期:2011-02-01 00:00:00

  • Bioavailability of tobacco-specific N-nitrosamines to the snuff dipper.

    abstract::Use of supercritical carbon dioxide extraction in the analysis of smokeless tobacco for tobacco-specific N-nitrosamines revealed the presence of higher levels of 4-(methylnitros-amino)-1-(3-pyridyl)-1-butanone (NNK) than had been determined with conventional methods. Whether human saliva may be similarly capable of re...


    pub_type: 杂志文章


    authors: Prokopczyk B,Wu M,Cox JE,Hoffmann D

    更新日期:1992-05-01 00:00:00

  • Dose and schedule of oral retinoic acid and indomethacin needed to effectively inhibit phorbol ester-induced epidermal ornithine decarboxylase activity.

    abstract::Currently there is no well-defined biological parameter or marker to help define agents, doses, and dose schedules for human cancer chemoprevention trials. Induction of ornithine decarboxylase, the rate limiting enzyme in the polyamine biosynthetic pathway, has been shown to be an essential aspect of mouse skin tumor ...


    pub_type: 杂志文章


    authors: Loprinzi CL,Verma AK

    更新日期:1985-11-01 00:00:00

  • Use of a mathematical model of rodent in vitro benzene metabolism to predict human in vitro metabolism data.

    abstract::Benzene, a ubiquitous environmental pollutant, is known to cause leukemia and aplastic anemia in humans and hematotoxicity and myelotoxicity in rodents. Toxicity is thought to be exerted through oxidative metabolites formed in the liver, primarily via pathways mediated by cytochrome P450 2E1 (CYP2E1). Phenol, hydroqui...


    pub_type: 杂志文章


    authors: Lovern MR,Maris ME,Schlosser PM

    更新日期:1999-08-01 00:00:00

  • Effect of vitamin C supplementation on gastric mucosal DNA damage.

    abstract::The effect of oral vitamin C supplementation on intragastric ascorbate levels and gastric mucosal DNA damage as measured by the 32P-postlabelling assay was assessed in 43 patients. In patients with normal gastric mucosa, treatment with vitamin C resulted in elevation of intragastric ascorbate levels in all cases. In t...


    pub_type: 杂志文章


    authors: Dyke GW,Craven JL,Hall R,Garner RC

    更新日期:1994-02-01 00:00:00