Abstract:
:Experiments were conducted to determine whether the natural estrogen and an environmental compound with estrogenic action, 4-n-octylphenol (4nOP), could modify tumor development in human c-Ha-ras proto-oncogene transgenic (Tg) rats which are highly susceptible to mammary and skin carcinogens. Female and male Tg and non-transgenic (non-Tg) rats were given a single oral dose of 7,12-dimethylbenz[a]anthracene (DMBA) (25 mg/kg body weight) at 50 days of age and thereafter subcutaneously implanted with cholesterol pellets containing 0.01, 0.1 or 1.0 mg beta-estradiol 3-benzoate (E2) per rat or received diets containing 1000 or 100 p.p.m. 4nOP for 12 weeks in females or for 20 weeks in males. E2 reduced the mammary tumor incidence and multiplicity in a dose dependent manner, especially in female Tg rats. In contrast, E2 increased mammary tumor incidence and multiplicity at the lowest dose (0.01 mg), however it reduced skin tumor induction in male Tg rats. 4nOP at a dose of 100 p.p.m. decreased mammary tumor multiplicity in female Tg rats (P < 0.001). No effects were observed in males. In separate in vitro studies, E2 at low doses (10(-11)-10(-8) M) enhanced the growth of both MCF-7 and T47D cells and this was similarly the case for 4nOP at high doses (10(-7)-10(-5) M) in T47D cells. The finding that E2 and 4nOP at high doses caused reduction in mammary tumor development in female Tg and possibly non-Tg rats, may indicate that excess estrogen can exert a paradoxical inhibitory influence. E2 also appears to have bipotential effects in males, promoting mammary, but inhibiting skin carcinogenesis. These contrasting observations may be caused by differences in background physiological estrogen levels. In addition, the results suggest that Tg rats can be used in medium-term bioassay models to test for the modifying effects of estrogenic environmental compounds on mammary tumor development.
journal_name
Carcinogenesisjournal_title
Carcinogenesisauthors
Han BS,Fukamachi K,Takasuka N,Ohnishi T,Maeda M,Yamasaki T,Tsuda Hdoi
10.1093/carcin/23.7.1209keywords:
subject
Has Abstractpub_date
2002-07-01 00:00:00pages
1209-15issue
7eissn
0143-3334issn
1460-2180journal_volume
23pub_type
杂志文章相关文献
CARCINOGENESIS文献大全abstract::Aberrant crypt foci (ACF), putative preneoplastic lesions, are early morphological changes induced by the colon carcinogen azoxymethane (AOM). Although inbred mice differ markedly in their susceptibility to AOM carcinogenesis, we have previously shown that ACF develop in both resistant and sensitive mouse strains afte...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:
更新日期:2000-08-01 00:00:00
abstract::We have previously demonstrated that the active dihydrofolate reductase (DHFR) gene is efficiently repaired in Chinese hamster ovary (CHO) cells which remove only a small fraction of u.v.-induced pyrimidine dimers from the overall genome. Preferential DNA repair of essential genes may explain why the u.v. resistance o...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/8.9.1333
更新日期:1987-09-01 00:00:00
abstract::Crude plasma membranes were prepared from the liver of control rats or of rats submitted to an initiation by diethyl-nitrosamine and selection with 2-acetylaminofluorene and carbon tetrachloride (group IS) or of rats submitted to an initiation-selection protocol followed by a promotion with phenobarbital (group IS PB)...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/12.4.659
更新日期:1991-04-01 00:00:00
abstract::The apoptotic response to DNA damage appears to be an innate biological mechanism for protection against tumourigenesis. It is possible that agents that protect against colorectal cancer act by enhancing the apoptotic deletion of cells suffering DNA damage, with consequent removal of those with tumourigenic mutations....
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/23.7.1131
更新日期:2002-07-01 00:00:00
abstract::Zinc has been shown to be accumulated in N-methyl-N-nitrosourea (MNU)-induced rat mammary tumors. Zinc is required for cell proliferation and tumorigenesis is characterized by dysregulation of cell proliferation. An accumulation of zinc in mammary tumors perhaps indicates a reliance on zinc to sustain tumor growth. Li...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgh214
更新日期:2004-10-01 00:00:00
abstract::Matrix metalloproteinases (MMP) are enzymes responsible for extracellular matrix degradation which play a role in cancer progression and metastatic spreading. We investigated the effects of the MMP inhibitor, batimastat, in vitro on the proliferation and invasiveness of the rat colon cancer cell line DHD/K12, and in v...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/20.8.1445
更新日期:1999-08-01 00:00:00
abstract::Forty-two compounds belonging to various chemical groups have been tested for their ability to suppress formation of aflatoxin B1--DNA adduct mediated by microsome in vitro. While many of these compounds have either marginal or no modulating effect, some have been identified as effective inhibitors. The strong inhibit...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/5.10.1359
更新日期:1984-10-01 00:00:00
abstract::Nitrosamine-induced hepatocarcinogenesis has been used to investigate the regulation and expression of different drug-metabolizing enzymes in preneoplastic and neoplastic lesions in the female Wistar rat. The enzymes investigated were two phenobarbital-inducible cytochrome P-450 (cyt. P-450) isoenzymes (PB1 and PB2, m...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/6.4.513
更新日期:1985-04-01 00:00:00
abstract::Pancreatic cancer has remained refractory to treatment. In large part, this results from the lack of an animal model that mimics pancreatic cancer in man. We describe a novel experimental model of pancreatic cancer that shares the genetic background, histologic features and natural history of human mixed acinar-ductal...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgx119
更新日期:2018-02-09 00:00:00
abstract::In order to determine the nature of the cytotoxic lesion(s) formed by the antitumour drugs cisplatin and carboplatin, a comparative study was made of bifunctional DNA-adduct formation by these drugs. The kinetics of bifunctional cisplatin adduct formation were studied with DNA in vitro and in cultured Chinese hamster ...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/16.10.2447
更新日期:1995-10-01 00:00:00
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...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgz171
更新日期:2020-07-14 00:00:00
abstract::4,4'-Methylene-bis(2-chloroaniline) (MOCA) can produce tumors in rodents and dogs and an increased incidence of bladder tumors has been reported in exposed workers. It is therefore of interest to identify the human cytochrome P450 (P450) enzymes involved in MOCA N-oxidation, the primary reaction involved in the format...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/13.2.217
更新日期:1992-02-01 00:00:00
abstract::The pulmonary adenoma susceptibility 1 (Pas1) gene affects susceptibility to the development of lung adenomas in mice with a subset of the adenomas progressing to adenocarcinoma (ADC). In this study, genotype distributions for 10 polymorphisms in the human counterparts for three mouse candidate Pas1 genes, KRAS, CASC1...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgn048
更新日期:2008-05-01 00:00:00
abstract::4-Oxo-4-(3-pyridyl)butanal (OPB) is an aldehyde formed during the activation of the tobacco-specific N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Using the DNA alkaline elution technique, the properties of DNA alkali-labile sites induced in the isolated rat hepatocytes by NNK and OPB were compar...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/12.11.2135
更新日期:1991-11-01 00:00:00
abstract::The effect of the aromatic amines 2-acetylaminofluorene (AAF), 2-acetylaminophenanthrene (AAP) and trans-4-acetylaminostilbene (AAS) on the rat hepatic aromatic hydrocarbon (Ah) receptor level was studied. 3-Methylcholanthrene (MC), as a known receptor ligand, was used as a control. The complete liver carcinogen AAF a...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/8.7.1021
更新日期:1987-07-01 00:00:00
abstract::N-Hydroxy-2-acetylaminofluorene (N-OH-AAF) was administered i.p. to male Wistar rats 17 h after partial hepatectomy. Hepatocytes were analyzed for the presence of micronuclei 7 h, 1, 2, 3 and 4 days after injection. N-OH-AAF treatment resulted in a high frequency of micronucleated hepatocytes at days 3 and 4 (19.5% an...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/10.4.717
更新日期:1989-04-01 00:00:00
abstract::The aim of this work was to optimize the ionic strength (tau) in the liver microsomal assay (LMA) in performing short-term genotoxicity tests. tau optimization would increase the sensitivity (i.e. decrease false negatives) and at the same time increase the specificity (decrease false positives). Such optimization depe...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/13.8.1403
更新日期:1992-08-01 00:00:00
abstract::Despite their individual key roles in promoting head and neck squamous cell carcinoma (HNSCC) progression and treatment resistance, little is known about the impact of intratumoral hypoxia on the activity of the epidermal growth factor receptor (EGFR) signaling pathway in this cancer type. Here, we show that in highly...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgq078
更新日期:2010-07-01 00:00:00
abstract::Epigenetic silencing of tumor suppressor genes commonly occurs in human cancers via increasing DNA methylation and repressive histone modifications at gene promoters. However, little is known about how pathogenic environmental factors contribute to cancer development by affecting epigenetic regulatory mechanisms. Prev...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgq197
更新日期:2010-12-01 00:00:00
abstract::Debrisoquine hydroxylase activity has been attributed to CYP2D6 and poor metabolizers of debrisoquine have a reduced relative risk of developing aggressive bladder cancer. Production of a proximate carcinogen could occur in liver or bladder mucosa. However, it is not known if CYP2D6 is expressed in human bladder mucos...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/15.9.1955
更新日期:1994-09-01 00:00:00
abstract::1,3-Dimethyl-3-phenyl-1-nitrosourea (DMPNU) shows no spontaneous decomposition in aqueous buffered solution (pH 7.0) at 37 degrees C over a measuring period of 10 days, but it is directly genotoxic in all assays applied. This compound induces base substitutions in Salmonella typhimurium (especially in the plasmid harb...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/4.4.409
更新日期:1983-01-01 00:00:00
abstract::A pilot study was conducted to determine whether any relationship exists between micronucleated cell rates of female uterine cervical epithelium and current smoking status. Cervical uterine cells obtained from 118 pre-menopausal females, seen between September 1994 and June 1995 at the Occupational Medecine Interprofe...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/18.4.749
更新日期:1997-04-01 00:00:00
abstract::To evaluate the significance of C-C chemokine receptor type 5 (CCR5) in lung tumor development, we compared carcinogen-induced tumor growth in CCR5 knockout (CCR5(-/-)) mice and wild-type (CCR5(+/+)) mice. CCR5(-/-) mice showed reduced urethane (1g/kg)-induced tumor incidence when compared with those of CCR5(+/+) mice...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgs265
更新日期:2012-12-01 00:00:00
abstract::Current procedures for diagnosis and biomarker examination of colorectal cancer (CRC) are invasive and unpleasant. There is a great need to identify sensitive and specific biomarkers for early diagnosis of CRC. Circulating microRNAs (miRNAs) are promising molecular markers for CRC prediction. We performed a comprehens...
journal_title:Carcinogenesis
pub_type: 杂志文章,随机对照试验
doi:10.1093/carcin/bgu189
更新日期:2014-12-01 00:00:00
abstract::DNA mismatch repair (MMR) deficiency results in a strong mutator phenotype and high-frequency microsatellite instability (MSI-H), which are the hallmarks of tumors arising within Lynch syndrome. MSI-H is characterized by length alterations within simple repeated sequences, microsatellites. Lynch syndrome is primarily ...
journal_title:Carcinogenesis
pub_type: 杂志文章,评审
doi:10.1093/carcin/bgm228
更新日期:2008-04-01 00:00:00
abstract::Previous studies have shown that 1- and 3-nitrobenzo[a]pyrene (NBaP) were mutagenic in the Salmonella reversion assay without exogenous activation and that 1-, 3- and 6-NBaP were mutagenic in the presence of hepatocytes or liver homogenate (S9). In the present study, 1-, 3- and 6-NBaP were tested for mutagenicity in C...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/7.4.681
更新日期:1986-04-01 00:00:00
abstract::A simple method for detection of DNA single-strand breaks (DNA-SSB) in cultured cells is described, based on filtration of alkaline-lysed cells through microfilters. After exposure to potentially DNA damaging agents, the cells are transferred to 0.8 micron cellulose acetate filters mounted in microfilter devices where...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/15.1.137
更新日期:1994-01-01 00:00:00
abstract::The natural flavonoid quercetin has been suggested by epidemiological studies to have preventive activity against lung cancer; however, the mechanism of which has not been well elucidated. In this report, we demonstrate that quercetin significantly enhances tumor necrosis factor-related apoptosis-inducing ligand (TRAI...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/bgm133
更新日期:2007-10-01 00:00:00
abstract::This report shows that generation of hydrogen peroxide (H2O2) by human polymorphonuclear leukocytes (PMNs) activated with tumor promoters of varying potency as first and second stage promoters correlates well with activities of these promoters in vivo. Those tested were 12-O-tetradecanoylphorbol-13-acetate (TPA), a co...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/8.3.455
更新日期:1987-03-01 00:00:00
abstract::We constructed a complementary DNA (cDNA) library from mRNAs of rat liver induced by an initiating dose of a chemical carcinogen, N-nitrosodiethylamine (DEN). Using a differential hybridization with cDNA probes prepared from mRNAs of control and DEN-treated rat liver, eight cDNAs of which expression was altered by an ...
journal_title:Carcinogenesis
pub_type: 杂志文章
doi:10.1093/carcin/15.8.1759
更新日期:1994-08-01 00:00:00