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Biochimica Et Biophysica Acta Dec 2013Conversion of protein -SH groups to disulfides is an early event during protein oxidation, which has prompted great interest in the study of thiol proteins. Chemical... (Comparative Study)
Comparative Study
Conversion of protein -SH groups to disulfides is an early event during protein oxidation, which has prompted great interest in the study of thiol proteins. Chemical carcinogenesis is strongly associated with the formation of reactive oxygen species (ROS). The goal of this study was to detect thiol proteins that are sensitive to ROS generated during diethylnitrosamine (DEN) metabolism in the rat liver. DEN has been widely used to induce experimental hepatocellular carcinoma. We used modified redox-differential gel electrophoresis (redox-DIGE method) and mass spectrometry MALDI-TOF/TOF to identify differential oxidation protein profiles associated with carcinogen exposure. Our analysis revealed a time-dependent increase in the number of oxidized thiol proteins after carcinogen treatment; some of these proteins have antioxidant activity, including thioredoxin, peroxirredoxin 2, peroxiredoxin 6 and glutathione S-transferase alpha-3. According to functional classifications, the identified proteins in our study included chaperones, oxidoreductases, activity isomerases, hydrolases and other protein-binding partners. This study demonstrates that oxidative stress generated by DEN tends to increase gradually through DEN metabolism, causes time-dependent necrosis in the liver and has an oxidative effect on thiol proteins, thereby increasing the number of oxidized thiol proteins. Furthermore, these events occurred during the hepatocarcinogenesis initiation period.
Topics: Alkylating Agents; Animals; Antioxidants; Diethylnitrosamine; Liver; Male; Necrosis; Oxidative Stress; Oxidoreductases; Proteome; Proteomics; Rats; Rats, Inbred F344; Sulfhydryl Compounds
PubMed: 23994225
DOI: 10.1016/j.bbapap.2013.08.005 -
Journal of Basic and Clinical... Jun 2021For designing early treatment for liver cancer, it is important to prepare an animal model to evaluate cancer prevention treatment by using inflammation disease. The...
OBJECTIVES
For designing early treatment for liver cancer, it is important to prepare an animal model to evaluate cancer prevention treatment by using inflammation disease. The hepatocarcinogenic N-Nitrosodiethylamine (NDEA) has been reportedly able to produce free radicals that cause liver inflammation leading to liver carcinoma. This study aimed to evaluate the inflammation disease model of mice induced with hepatocarcinogenic NDEA for five weeks induction.
METHODS
The BALB-c mice were induced with NDEA 25 mg/kg of body weight once a week for five weeks intraperitonially and it was then evaluated for the body weight during study periods. The mice were then sacrificed and excised for evaluating their organs including physical and morphological appearances and histopathology evaluations.
RESULTS
The results showed a significant decrease of body weight of mice after five times induction of 25 mg NDEA/kgBW per week intraperitonially. Different morphological appearances and weight of mice organs specifically for liver and spleen had also been observed. The histopathology examination showed that there were hepatic lipidosis and steatohepatitis observed in liver and spleen, respectively that might indicate the hepatocellular injury.
CONCLUSIONS
It can be concluded that inducing mice with NDEA intraperitonially resulted in fatty liver disease leading to progress of cancer disease.
Topics: Animals; Body Weight; Diethylnitrosamine; Inflammation; Liver; Liver Neoplasms, Experimental; Mice; Mice, Inbred BALB C
PubMed: 34214328
DOI: 10.1515/jbcpp-2020-0475 -
Carcinogenesis Feb 1996Caloric restriction causes a generalized decrease in growth rate and has been repeatedly associated with an inhibitory effect on cancer development in several systems....
Caloric restriction causes a generalized decrease in growth rate and has been repeatedly associated with an inhibitory effect on cancer development in several systems. In contrast, exposure to complete fasting followed by refeeding is a metabolic condition associated with increased cell turnover in different organs, including the liver. The present study examines whether such condition is able to sustain the induction of initiated hepatocytes following a subnecrogenic dose of diethylnitrosamine (DENA). Male Fisher-344 rats were fasted for 4 days and 1 day after refeeding they were given a single dose of DENA (20 or 200 mg/kg body wt, i.p.). Negative and positive control groups were fed ad libitum and injected with 20 and 200 mg/kg of DENA, respectively. One week later all animals were subjected to the resistant hepatocyte model for the selection of hepatocyte nodules and they were killed 2 weeks thereafter. Results indicated the presence of gamma-glutamyltransferase (GGT) positive foci and nodules (38 +/- 7/cm2) in rats regularly fed and given 200 mg/kg of DENA, while virtually no focal lesions (< 1/cm2) were found in the group receiving 20 mg/kg of DENA and fed throughout the experiment. However, a significant number of GGT positive foci/nodules (14 +/- 7) also developed in rats exposed to fasting and given 20 mg/kg of DENA 24 h after refeeding. No evidence of hepatocellular necrosis was found in the latter group following DENA administration. No effect of fasting was observed when rats received 200 mg/kg of DENA. It is concluded that fasting/refeeding provides conditions which are able to sustain initiation in rat liver by a subnecrogenic dose of a carcinogen. These findings are in contrast with the commonly reported inhibitory effect of chronic food restriction on various stages of carcinogenesis, including initiation.
Topics: Animals; Carcinogens; Diethylnitrosamine; Eating; Enzyme Induction; Fasting; Glutathione Transferase; Liver; Liver Neoplasms, Experimental; Male; Rats; Rats, Inbred F344; gamma-Glutamyltransferase
PubMed: 8625452
DOI: 10.1093/carcin/17.2.289 -
Cancer Research Mar 1987There is considerable interest in incorporating mechanistically based biological data into the process of quantitative risk assessment. Presently, no adequate data bases...
There is considerable interest in incorporating mechanistically based biological data into the process of quantitative risk assessment. Presently, no adequate data bases for internal dosimeters, such as DNA adducts, exist for humans or experimental animals. Therefore, the major promutagenic ethyl adduct, O4-ethyldeoxythymidine (O4-EtdT), has been quantitated in liver DNA after continuous exposure of rats to drinking water containing 0.4, 1, 4, 10, 40, or 100 ppm diethylnitrosamine (DEN) for 1, 4, 7, 14, 28, 49, or 70 days. The rate of O4-EtdT accumulation was modeled as the difference between a DEN-dependent rate of formation and an O4-EtdT concentration-dependent rate of loss. In general, O4-EtdT concentrations increased rapidly during the first 7 days of exposure and by 7-28 days O4-EtdT had accumulated to apparent steady-state concentrations that were DEN concentration-dependent over the entire dose range. The concentration of the adduct increased with DEN concentration over the entire dose range for exposures of 28 days or less and for doses of 0.4 to 40 ppm DEN the adduct level increased with DEN concentration for exposures of 70 days or less. Although the dose response of O4-EtdT was relatively linear, with increasing DEN concentration a trend toward a less than linear relationship was observed. This suggests that there was a lower efficiency of formation and/or greater loss of O4-EtdT during high-dose exposures. This study provides a data base that can be used to qualitatively and quantitatively examine the relationship between external dose and O4-EtdT over a DEN dose range covering several orders of magnitude.
Topics: Animals; DNA; Diethylnitrosamine; Dose-Response Relationship, Drug; Half-Life; Male; Rats; Rats, Inbred F344; Thymidine
PubMed: 3815358
DOI: No ID Found -
Free Radical Biology & Medicine Jun 2006Diethylnitrosamine (DEN) is a well-known carcinogenic substance that requires microsomal activation before it can react with DNA to cause mutations and cancer. The aim...
Diethylnitrosamine (DEN) is a well-known carcinogenic substance that requires microsomal activation before it can react with DNA to cause mutations and cancer. The aim of this study was to use in vivo spin trapping and spin probe techniques to investigate whether free radicals are generated in rat liver tissue during DEN activation. We used alpha-phenyl-n-tert-butylnitrone (PBN) as the spin trapping agent, which was delivered through an intraperitoneal injection before DEN administration. One hour after DEN administration, multicomponent PBN adducts in the bile were detected, and the intensities were diminished by the cytochrome P450 inhibitor SKF-525A. A computer simulation of the ESR signals revealed the presence of a lipid-derived radical. Using the in vivo spin probe/ESR technique, the signal decay rate of methoxycarbonyl-PROXYL was significantly increased in the DEN-treated group compared with the rate in the vehicle group. The enhanced signal decay rate was restored with PBN and/or SKF-525A pretreatment. These results suggested that lipid-derived free radicals were generated in the liver within 1 h after DEN administration.
Topics: Animals; Bile; Diethylnitrosamine; Electron Spin Resonance Spectroscopy; Free Radicals; Lipid Peroxidation; Male; Microsomes, Liver; Rats; Rats, Inbred F344
PubMed: 16716904
DOI: 10.1016/j.freeradbiomed.2006.01.031 -
Pharmacology & Therapeutics 1996N-Nitrosodiethylamine (NDEA) is DNA reactive after bioactivation and produces tumors in every animal species tested. Bioactivation is effected by several P450 isozymes... (Review)
Review
N-Nitrosodiethylamine (NDEA) is DNA reactive after bioactivation and produces tumors in every animal species tested. Bioactivation is effected by several P450 isozymes including CYP2E1, which is ethanol inducible. Tumor formation in rat liver was proportional to O4-ethyldeoxythymidine formation in DNA, which was generally proportional to NDEA dose. At low doses in the 0.033-1.1 ppm range, the dose-response for esophageal tumor formation was sublinear, possibly due to DNA repair. Although no epidemiological studies have specifically evaluated NDEA, sufficient exposure levels would be expected to cause cancer in humans.
Topics: Animals; Biotransformation; Carcinogens; DNA; DNA Adducts; Diethylnitrosamine; Humans; Mutagenicity Tests; Neoplasms; Rats; Risk Assessment
PubMed: 8910949
DOI: 10.1016/0163-7258(96)00062-9 -
Environmental Toxicology and... Nov 2014The presence of carcinogenic compounds in the aquatic environment is a recognized problem. ABC transporters are well known players in the multidrug-resistance (MDR)...
The presence of carcinogenic compounds in the aquatic environment is a recognized problem. ABC transporters are well known players in the multidrug-resistance (MDR) phenomenon in mammals associated with resistance to chemotherapy, however little is known in fish species. Thus, the aim of this study was to induce hepatic tumours and evaluate long-term effects on P-glycoprotein (P-gp) and proliferating cell nuclear antigen (PCNA) proteins in Danio rerio liver, after exposure to diethylnitrosamine (DEN). Several hepatic histopathological alterations were observed in zebrafish after exposure to DEN including pre-neoplastic lesions 6 and 9 months post-exposure. After 3, 6 and 9 months of exposure to DEN, P-gp and PCNA proteins expression were up-regulated. In conclusion, this study has shown that zebrafish ABC transporters can play a similar role as in human disease, hence zebrafish can be used also as a biological model to investigate in more deep mechanisms involved in disease processes.
Topics: ATP Binding Cassette Transporter, Subfamily B; Animals; Carcinogens; Diethylnitrosamine; Female; Gene Expression Regulation, Neoplastic; Liver; Male; Proliferating Cell Nuclear Antigen; Zebrafish
PubMed: 25299848
DOI: 10.1016/j.etap.2014.09.002 -
Mutation Research Apr 1982DEN is an established animal carcinogen, and is effective transplacentally; but like other nitrosamines, its genotoxicity is difficult to assess in established shortterm...
DEN is an established animal carcinogen, and is effective transplacentally; but like other nitrosamines, its genotoxicity is difficult to assess in established shortterm cytogenetic tests. The mouse transplacental micronucleus test demonstrates the ability of DEN to cause chromosome breakage in utero. Positive results were obtained from the 15th day of gestation and a linear dose-response relationship is expressed when micronucleated polychromatic erythrocytes are measured in neonatal blood, after transplacental exposure late in gestation. 25mg/kg (the lowest dose tested) caused a significant increase in MNPCEs (p less than 0.05). A micronucleus test based on polychromatic erythrocytes in neonatal blood permits maximal exploitation of the metabolic capacity of the prenatal liver and is therefore sensitive to clastogenic chemicals not activated by adult bone marrow.
Topics: Animals; Carcinogens; Cell Nucleus; Diethylnitrosamine; Dose-Response Relationship, Drug; Erythrocytes; Female; Fetal Blood; Maternal-Fetal Exchange; Mice; Mutagenicity Tests; Mutagens; Nitrosamines; Pregnancy
PubMed: 7078570
DOI: 10.1016/0165-7992(82)90139-7 -
Cancer Letters Jul 1980The formation by diethylnitrosamine (DEN) and persistence of O4-ethylthymidine in rat liver DNA in vivo has been studied using enzymic hydrolysis of DNA, cation exchange...
The formation by diethylnitrosamine (DEN) and persistence of O4-ethylthymidine in rat liver DNA in vivo has been studied using enzymic hydrolysis of DNA, cation exchange column chromatography and thin-layer chromatography (TLC). The amount of O4-ethylthymidine represented about 1% of the total ethylation; its half-life in vivo was 19 (range 16--24) days, the same value as obtained for O2-ethylthymidine. The persistence of O2- and O4-ethylthymidine, rather than the rapid removal of O6-ethylguanine, favours the former miscoding base adducts as relevant molecular lesions in rat liver carcinogenesis.
Topics: Alkylation; Animals; DNA; Diethylnitrosamine; Female; Liver; Nitrosamines; Rats; Thymidine
PubMed: 7226125
DOI: 10.1016/0304-3835(80)90058-0 -
Roczniki Akademii Medycznej W... 2003To assess the possibility of promoting esophageal squamous cell carcinoma after direct administration of diethylnitrosamine (DEN) into the wall of the esophagus.
PURPOSE
To assess the possibility of promoting esophageal squamous cell carcinoma after direct administration of diethylnitrosamine (DEN) into the wall of the esophagus.
MATERIAL AND METHODS
Adult male Wistar rats weighing 250-300 g were used in the studies. Via laparotomy, solution of DEN (at the volume of 0.1 ml) was injected directly into the esophageal wall. Animals were divided into 3 groups: CONTROL group--injected with saline, DEN1 group--injected with DEN 100 mg, DEN2 group--injected twice with DEN at the dose of 100 mg with 7 days interval (total dose of 200 mg).
RESULTS
Microscopic evaluation after 180 days revealed signs of esophagitis in 20% and 30% subjects in DEN1 and DEN2 group respectively. In 30% of animals from DEN1 and 50% animals from DEN2 group, low-grade dysplasia was recognized. The difference between DEN2 and control animals was statistically significant with p < 0.03. Neither high-grade dysplasia nor invasive carcinoma were found in both experimental groups. None of the liver specimens showed the evidence of pathology.
CONCLUSIONS
These initial results may indicate the possibility of development of premalignant lesions after local administration of carcinogen into esophageal wall. Observed changes were limited exclusively to esophagus which became the "target organ" in this model.
Topics: Alkylating Agents; Animals; Diethylnitrosamine; Esophageal Neoplasms; Injections; Male; Models, Animal; Precancerous Conditions; Rats; Rats, Wistar
PubMed: 14737940
DOI: No ID Found