O' Connor, T.P.; Peterson, F.; Campbell, T.C.
The effect of dietary menhaden oil on 7,12-dimethylbenzanthracene (DMBA) induced mammary tumorigenesis was examined in female Sprague-Dawley rats. Rats were obtained at age 28 days and acclimated until age 50 days when they received a single i.g. dose of 5 mg DMBA dissolved in 1 ml corn oil. Rats were then randomly assigned to one of four treatment groups with 25 rats per group. One group was fed a diet based on fish protein (freeze-dried cod) and corn oil (F/C). The second group received a diet based on fish protein and menhaden oil (F/M). The third group received a casein based diet with corn oil as the lipid source (C/C). The fourth group was fed a casein based diet with menhaden oil as the lipid source (C/M). Both the protein and lipid sources were fed at a level of 20% by weight of the diets. Rats were palpated weekly to check for mammary tumor development and the experiment was terminated 24 weeks after DMBA administration. Rats fed menhaden oil as a lipid source (F/M and C/M groups) developed significantly fewer mammary tumors than animals on the corn oil based diets (F/C and C/C groups, respectively). Thus, menhaden oil, rich in omega-3 fatty acids, significantly inhibited the development of DMBA induced mammary tumors in this experiment.
Krishna Duro de Oliveira
Full Text Available Polycyclic aromatic hydrocarbons are known carcinogens used in rodent experimental models. In this study, the carcinogen DMBA (7,12-dimethylbenzanthracene was administered by gavage, diluted in corn oil, to female BALB / c mice at hebdomadary doses of 1 mg per animal for 1, 3, 6 or 9 weeks. Animals were weighed and monitored weekly until death. Remaining animals were euthanized at the age of 53 weeks. At necropsy, representative fragments of neoplasms were collected and routinely processed for histopathological analysis. Of all mice that received DMBA, 68.57% developed some type of tumor. Of the 70 mice treated with various doses of DMBA, 22 (31.43% developed mammary tumors. The adenoacanthoma was the most commonly (18.75% diagnosed histological type of breast cancer. Lung (15.71%, lymphoid tissue (11.43%, stomach (7.14% and skin (2.86% were also primary sites of tumor development. One third (33.33% of the mice receiving 1 mg of DMBA developed lung cancer. Therefore, the administration of DMBA was shown to be an efficient model of carcinogenesis in mice, especially for the study of breast cancer, when using the highest dose, and lung, when using the lowest dose. Carcinogenesis models have been used for several purposes in cancer research. These results represent new facts for a classic carcinogenesis model.
Wang, S.Y.; Smith, D.M.
Four materials, Silastic 386 Foam Elastomer, Irganox 1010, Sylgard 184 with Encapsulating Resin and Curing Agent, and 7,12-dimethylbenzanthracene (DMBA), were tested for in vitro mutagenicity by the Ames Salmonella assay method. Silastic 386 Foam Elastomer, Irganox 1010, and Sylgard 184 Encapsulating Resin with Curing Agent were not mutagenic; the mutagenicity of DMBA was corroborated.
Kim, Ji Young [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Lee, Seung Gee [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Chung, Jin-Yong [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Kim, Yoon-Jae [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Park, Ji-Eun [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Oh, Seunghoon [Department of Physiology, College of Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Lee, Se Yong [Department of Obstetrics and Gynecology, Busan Medical Center, Busan 611-072 (Korea, Republic of); Choi, Hong Jo [Department of General Surgery, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Yoo, Young Hyun, E-mail: firstname.lastname@example.org [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); and others
7,12-Dimethylbenzanthracene (DMBA), a polycyclic aromatic hydrocarbon, exhibits mutagenic, carcinogenic, immunosuppressive, and apoptogenic properties in various cell types. To achieve these functions effectively, DMBA is modified to its active form by cytochrome P450 1 (CYP1). Exposure to DMBA causes cytotoxicity-mediated apoptosis in bone marrow B cells and ovarian cells. Although uterine endometrium constitutively expresses CYP1A1 and CYP1B1, their apoptotic role after exposure to DMBA remains to be elucidated. Therefore, we chose RL95-2 endometrial cancer cells as a model system for studying DMBA-induced cytotoxicity and cell death and hypothesized that exposure to DMBA causes apoptosis in this cell type following CYP1A1 and/or CYP1B1 activation. We showed that DMBA-induced apoptosis in RL95-2 cells is associated with activation of caspases. In addition, mitochondrial changes, including decrease in mitochondrial potential and release of mitochondrial cytochrome c into the cytosol, support the hypothesis that a mitochondrial pathway is involved in DMBA-induced apoptosis. Exposure to DMBA upregulated the expression of AhR, Arnt, CYP1A1, and CYP1B1 significantly; this may be necessary for the conversion of DMBA to DMBA-3,4-diol-1,2-epoxide (DMBA-DE). Although both CYP1A1 and CYP1B1 were significantly upregulated by DMBA, only CYP1B1 exhibited activity. Moreover, knockdown of CYP1B1 abolished DMBA-induced apoptosis in RL95-2 cells. Our data show that RL95-2 cells are susceptible to apoptosis by exposure to DMBA and that CYP1B1 plays a pivotal role in DMBA-induced apoptosis in this system. -- Highlights: ► Cytotoxicity-mediated apoptogenic action of DMBA in human endometrial cancer cells. ► Mitochondrial pathway in DMBA-induced apoptosis of RL95-2 endometrial cancer cells. ► Requirement of ligand-selective activation of CYP1B1 in DMBA-induced apoptosis.
Prasanna, H.R.; Schwartz, A.; Hacobian, N.; Magee, P.N.
The possibility that the anticarcinogenic action of the naturally occurring steroid DHEA could arise from its interference in the metabolic activation of DMBA was investigated. Young mature male Sprague Dawley rats were fed for 14 days with a diet containing a nontoxic dose of DHEA in the diet. Control rats were pairfed and received the same diet except DHEA. The animals were given interperitoneally 120 ..mu..Ci of (/sup 3/H)DMBA in DMSO. After 48 hours the rats were sacrificed. Liver weights at sacrifice were 11.7 +/- 0.9 g and 7.1 g +/- 0.6 g for DHEA fed and control animals respectively. Protein content of whole liver and hepatic microsomal protein was significantly higher in DHEA fed animals. Binding of DMBA to hepatic DNA was 6688 +/- 1308 and 4070 +/- 890 dpm/mg DNA for control and DHEA fed animals respectively. Furthermore the excretion of DMBA derived radioactivity in urine was 2.3 fold more in DHEA fed animals. These results suggest that DHEA could protect rats from the carcinogenic manifestations of DMBA by interfering at the biotransformation step of the carcinogen.
El-Ela, S.H.A.; Bunce, O.R.
Evening primrose oil (PO) contains 9% gamma-linolenic acid (GLA) and 75% linoleic acid (LA) each of which are prostaglandin precursors. Corn oil (CO) contains 60% linoleic acid. Fifty day old virgin female rats were given DMBA (5 mg, intragastric). Three weeks post DMBA the rats were separated into two dietary groups of 20% PO and 20% CO, respectively. At 16 weeks post DMBA the rats were killed and mammary tumors analyzed by RIA for PGE/sub 1/, PGE/sub 2/, and 6-keto F/sub 1..cap alpha... PGE/sub 1/ levels in PO fed animals were increased two fold over those fed CO indicating that it is possible to shunt GLA toward monoenoic eicosanoid synthesis. However PGE/sub 2/ and 6 keto F/sub 1..cap alpha../ levels were 5x higher in PO compared to CO. Although this could be attributed to higher cis linoleic acid content of PO, more subtle mechanisms may be responsible.
Lillie, Madeline A; Ambrus, Clara M; Pickren, John W; Akhter, Selina; Islam, Abul; Ambrus, Julian L
Eight female Macaca arctoides monkeys were given dimethylbenzanthracene (DMBA) directly into the milk ducts. During a 4-year observation period, ending with euthanasia and autopsy, no mammary cancers were noticed. However, one animal developed a superficial localized squamous cell carcinoma. DMBA is highly carcinogenic in rodents, e.g. producing a high incidence of breast cancer in C3H mice. It was concluded that carcinogenicity testing should be extended beyond testing in rodents to non-human primates in order to distinguish "primary rodent carcinogens" from those highly active in primates as well. Studies are in progress to study carcinogens in human cell lines transplanted into nu/nu mice.
Corominas, M.; Sloan, S.R.; Leon, J.; Kamino, Hideko; Newcomb, E.W.; Pellicer, A. (New York Univ. Medical Center, New York (United States))
Environmental agents such as radiation and chemicals are known to cause genetic damage. Alterations in a limited set of cellular genes called proto-oncogenes lead to unregulated proliferation and differentiation. The authors have studied the role of the ras gene family in carcinogenesis using two different animal models. In one case, thymic lymphomas were induced in mice by either gamma or neutron radiation, and in the other, keratoacanthomas were induced in rabbit skin with dimethylbenzanthracene. Human keratoacanthomas similar to the ones induced in rabbits were also analyzed. They found that different types of radiation such as gamma rays and neutrons, induced different point mutations in ras genes. A novel K-ras mutation in codon 146 has been found in thymic lymphomas induced by neutrons. Keratoacanthomas induced in rabbit skin by dimethylbenzanthracene show a high frequency of H-ras-activated genes carrying a mutation in codon 61. The same is observed in human keratoacanthomas, although mutations are in both the 12th and the 61st codons of the H-ras gene. H-ras activation is less frequent in human squamous cell carcinomas than in keratoacanthomas, suggesting that ras genes could play a role in vivo in differentiation as well as in proliferation.
Ronis, Martin J; Hakkak, Reza; Korourian, Soheila; Badger, Thomas M
Effects of intact and processed bovine milk proteins on development of chemically induced mammary tumors in female rats were compared. AIN-93G diets were made with 20% casein (CAS), casein hydrolysate (CASH), intact whey protein (IWP), or whey protein hydrolysate (WPH). Pregnant Sprague-Dawley rats were fed the diets starting at Gestational Day 4. Offspring were fed the same diet. At 50 days, female offspring (44-49/group) were gavaged with sesame oil containing 80 mg/kg of the mammary carcinogen dimethylbenzanthracene (DMBA) and euthanized 62 days posttreatment. Rats fed WPH had an adenocarcinoma incidence of 17% compared to the rats fed CAS, CASH, and IWP diets (34%, 33%, and 36% respectively) (P whey protein is required for this diet to be effective in reducing DMBA-induced mammary tumors. The bioactive compounds produced during whey protein processing and mechanisms underlying the anticancer effects of WPH are yet to be identified.
Ravdin, P.M.; Jordan, V.C.
Immunization of female rats with a bovine serum albumin-luteinizing hormone releasing hormone conjugate results in suppression of dimethylbenzanthracene mammary tumor incidence. Tumor incidence was 1.3, and 1.29 tumors per rat in bovine serum albumin alone (n = 10) and unimmunized (n = 18) control groups, but no tumors were found in the bovine serum albumin-luteinizing hormone releasing hormone conjugate immunized animals (n = 10). In a second experiment immunization with bovine serum albumin-luteinizing hormone releasing hormone conjugates reduced tumor incidence to 0.3 tumors per rat (n = 10) from the 1.2 tumors per animal seen in the control animals (n = 10) immunized with bovine serum albumin alone. Bovine serum albumin-luteinizing hormone immunization caused the production of anti-LHRH antibodies, an interruption of estrous cycles, lowered serum estradiol and progesterone levels, and atrophy of the ovaries and uteri. Immunization BSA-hormone conjugates is a novel anti-tumor strategy.
Tan, Xue-Mei; Ye, Hua; Yang, Kai; Chen, Dan; Wang, Qing-Qing; Tang, Hong; Zhao, Ning-Bo
Previous studies have suggested that the expression of clock genes have circadian rhythms, and many cell cycle genes are regulated by clock genes. The disruption of circadian rhythms appears to be associated with the acceleration of cancer development. To investigate the circadian patterns of the clock gene Per2 and of cell cycle genes p53, Cyclin D1, CDK1 and Cyclin B1 in different stages of carcinogenesis, the daily mRNA profiles of these genes were detected by real-time RT-PCR in dimethylbenzanthracene-induced cancer, in precancerous lesions and in normal tissues. Per2, p53, Cyclin D1 and CDK1 showed circadian rhythms in the 3 different stages of carcinogenesis, whereas the circadian rhythm of Cyclin B1 was absent in the precancerous lesions. The mesors and amplitudes of Per2 and p53 were decreased (P circadian pattern variations of these genes in different stages of carcinogenesis.
Modulating Effect of Hypnea musciformis (Red Seaweed) on Lipid Peroxidation, Antioxidants and Biotransforming Enzymes in 7,12-Dimethylbenz (a) Anthracene Induced Mammary Carcinogenesis in Experimental Animals
Balamurugan, Mohan; Sivakumar, Kathiresan; Mariadoss, Arokia Vijaya Anand; Suresh, Kathiresan
Background: Breast cancer is the second most widespread diagnosed cancer and second leading cause of cancer death in women. Objective: The present work was carried out to evaluate the chemo preventive potential of Hypnea musciformis (ethanol extract) seaweed on oxidative stress markers, bio transforming enzymes, incidence of tumors, and pathological observation in 7,12-dimethylbenzanthracene (DMBA) exposed experimental mammary carcinogenesis. Materials and Methods: Female Sprague–Dawley rats were randomly divided into four groups. Rats in the group 1 served as control. Rats in the group 2 and 3 received a single subcutaneous injection of DMBA (25 mg/kg body weight (b.w)) in the mammary gland to develop mammary carcinoma. In addition, group 3 rats were orally administrated with 200 mg/kg between of H. musciformis along with DMBA injection and group 4 rats received ethanolic extract of H. musciformis every day orally (200 mg/kg b.w) throughout the experimental period of 16 weeks. Results: Our results revealed that treatment with H. musciformis ethanolic extract to DMBA treated rats significantly reduced the incidence of tumor and tumor volume as compared to DMBA alone treated rats. Moreover, our results showed imbalance in the activities/levels of lipid peroxidation by products, antioxidant enzymes, and bio transforming phase I and II enzymes in the circulation, liver and mammary tissues of DMBA treated rats which were significantly modulated to near normal on treatment with ethanolic extract of H. musciformis. All these alterations were supported by histochemical findings. Conclusion: The results obtained from this study suggest that chemo preventive potential of H. musciformis ethanol extract is probably due to their free radicals quenching effect and modulating potential of bio transforming enzymes during DMBA exposed experimental mammary carcinogenesis. SUMMARY DMBA is a source of well-established site specific carcinogenHypnea musciformis act as a free radical
Frazier, M.E.; Samuel, J.E.
A Chinese hamster ovary (CHO) mammalian cell assay was used to evaluate the genotoxicity of complex mixtures (synthetic fuels). The genotoxicity (mutagenic potency) of the mixtures increased as the temperature of their boiling range increased. Most of the genotoxicity in the 750/sup 0/F+ boiling-range materials was associated with the neutral polycyclic aromatic hydrocarbon (PAH) fractions. Chemical analysis data indicate that the PAH fractions of high-boiling coal liquids contain a number of known chemical carcinogens, including five- and six-ring polyaromatics (e.g., benzo(a)pyrene) as well as four- and five-ring alkyl-substituted PAH (e.g., methylchrysene and dimethylbenzanthracenes); concentrations are a function of boiling point (bp). In vitro genotoxicity was also detected in fractions of nitrogen-containing polyaromatic compounds, as well as in those with aliphatics of hydroxy-containing PAH. Mutagenic activity of some fractions was detectable in the CHO assay in the absence of an exogenous metabolic activation system; in some instances, addition of exogenous enzymes and cofactors inhibited expression of the direct-acting mutagenic potential of the fraction. These data indicate that the organic matrix of the chemical fraction determines whether, and to what degree, various mutagens are expressed in the CHO assay. Therefore, the results of biological assays of these mixtures must be correlated with chemical analyses for proper interpretation of these data. 29 references, 16 figures, 4 tables.
Quesnot, Nicolas; Rondel, Karine; Audebert, Marc; Martinais, Sophie; Glaise, Denise; Morel, Fabrice; Loyer, Pascal; Robin, Marie-Anne
The in situ detection of γH2AX was recently reported to be a promising biomarker of genotoxicity. In addition, the human HepaRG hepatoma cells appear to be relevant for investigating hepatic genotoxicity since they express most of drug metabolizing enzymes and a wild type p53. The aim of this study was to determine whether the automated in situ detection of γH2AX positive HepaRG cells could be relevant for evaluation of genotoxicity after single or long-term repeated in vitro exposure compared to micronucleus assay. Metabolically competent HepaRG cells were treated daily with environmental contaminants and genotoxicity was evaluated after 1, 7 and 14 days. Using these cells, we confirmed the genotoxicity of aflatoxin B1 and benzo(a)pyrene and demonstrated that dimethylbenzanthracene, fipronil and endosulfan previously found genotoxic with comet or micronucleus assays also induced γH2AX phosphorylation. Furthermore, we showed that fluoranthene and bisphenol A induced γH2AX while no effect had been previously reported in HepG2 cells. In addition, induction of γH2AX was observed with some compounds only after 7 days, highlighting the importance of studying long-term effects of low doses of contaminants. Together, our data demonstrate that automated γH2AX detection in metabolically competent HepaRG cells is a suitable high-through put genotoxicity screening assay.
McCreery, Melissa Q; Halliwill, Kyle D; Chin, Douglas; Delrosario, Reyno; Hirst, Gillian; Vuong, Peter; Jen, Kuang-Yu; Hewinson, James; Adams, David J; Balmain, Allan
Human tumors show a high level of genetic heterogeneity, but the processes that influence the timing and route of metastatic dissemination of the subclones are unknown. Here we have used whole-exome sequencing of 103 matched benign, malignant and metastatic skin tumors from genetically heterogeneous mice to demonstrate that most metastases disseminate synchronously from the primary tumor, supporting parallel rather than linear evolution as the predominant model of metastasis. Shared mutations between primary carcinomas and their matched metastases have the distinct A-to-T signature of the initiating carcinogen dimethylbenzanthracene, but non-shared mutations are primarily G-to-T, a signature associated with oxidative stress. The existence of carcinomas that either did or did not metastasize in the same host animal suggests that there are tumor-intrinsic factors that influence metastatic seeding. We also demonstrate the importance of germline polymorphisms in determining allele-specific mutations, and we identify somatic genetic alterations that are specifically related to initiation of carcinogenesis by Hras or Kras mutations. Mouse tumors that mimic the genetic heterogeneity of human cancers can aid our understanding of the clonal evolution of metastasis and provide a realistic model for the testing of novel therapies. PMID:26523969
Battani, Somashekhar; Pawar, Harish; Suresh, Sarasija
The objective of the present investigation was formulation of raloxifene loaded solid lipid nanoparticles (R-SLN) for oral administration and evaluation of its anticancer potential in 7,12- dimethylbenzanthracene (DMBA)-induced breast cancer in Sprague-Dawley rats. Optimized R-SLN formulation prepared by modified micro-emulsion method resulted in R-SLN of 288.0±28.5 nm size and 95.56% entrapment efficiency. R-SLN exhibited in vitro prolonged release of raloxifene for 72 h in phosphate buffered saline. R-SLN was stable in simulated gastro-intestinal (GIT) fluids consisting of pH 1.2, pH 7.4, simulated gastric fluid and simulated intestinal fluid. A two-fold increase was observed in raloxifene oral bioavailability from R-SLN. R-SLN exhibited enhanced efficacy and chemopreventive activity over pure raloxifene as indicated by evaluation of tumor burden (P solid lipid nanoparticles in optimizing chemoprevention of breast cancer by R-SLN.
Krishna Duro de Oliveira
Full Text Available Gap junctions are communicating junctions which are important for tissue homeostasis, and their disruption is involved in carcinogenic processes. This study aimed to verify the influence of deletion of one allele of the Connexin 43 gene on cancer incidence in different organs. The 7, 12-dimethylbenzanthracene (DMBA carcinogenic model, using hebdomadary doses by gavage of 9 mg per animal, was used to induce tumors in Connexin 43 heterozygous or wild-type mice. The experiment began in the eighth week of the mice life, and all of them were euthanized when reaching inadequate physical condition, or at the end of 53 weeks. No statistical differences occurred for weight gain and cancer survival time (P=0.9853 between heterozygous and wild-type mice. Cx43+/− mice presented significantly higher susceptibility to lung cancer (P=0.0200 which was not evidenced for benign neoplasms (P=0.3449. In addition, incidence of ovarian neoplasms was 2.5-fold higher in Cx43+/− mice, although not statistically significant. Other organs showed a very similar cancer occurrence between Cx43 groups. The experiment strengthens the evidence of the relationship between Connexin 43 deficiency and carcinogenesis.
Corina V. Sasso
Full Text Available Prolactin (PRL is a key player in the development of mammary cancer. We studied the effects of parity or hyperprolactinemia on mammary carcinogenesis in OFA hr/hr treated with 7,12-dimethylbenzanthracene. They were divided into three groups: nulliparous (Null, primiparous (PL, after pregnancy and lactation, and hyperprolactinemic rats (I, implanted in the arcuate nucleus with 17β-estradiol. The tumor incidence was similar in the three groups. However, a higher percentage of regressing tumors was evident in the PL group. Serum PRL, mammary development, and mammary β-casein content were higher in I rats compared to Null. The expression of hormone receptors was similar in the different groups. However, mammary tissue from PL rats bearing tumors had increased expression of PRL and estrogen alpha receptors compared to rats free of tumors. Our results suggest that serum PRL levels do not have relevance on the incidence of tumors, probably because the low levels of PRL in OFA rats are not further decreased by PL like in other strains. However, supraphysiological levels of PRL affect carcinogenesis. PL induces regression of the tumors due to the differentiation produced on the mammary cells. Alterations in the expression of hormonal receptors may be involved in progression and regression of tumors.
Ana Milena Serrano Contreras
Full Text Available This study determines the effect of Morindia citrifolia juice (Tahitian Noni® in the development of breast cancer induced by carcinogen agent 7.12-dimethylbenzanthracene (DMBA in rats. For this purpose, the breast cancer induction model 1.7-DMBA was used on Spraguey Dawley nulliparous rats of 35 days of age, randomly divided into three groups: group 1 control, which received no treatment, and groups 2 and 3, induced with DMBA at a dose of 55 mg/kg. The latter received a dose of noni juice of 4 ml/kg per day for 90 days. The results showed that a significant percentage (83.33% of the rats from the group induced with DMBA not treated with noni juice developed palpable breast tumors ( ≤ 2 cm of the ductal carcinoma in situ type and atypical ductal hyperplasia, compared to the other groups that did not develop any kind of tumors. In addition, it was found that rats that developed breast cancer had a lower weight gain and significantly increased water consumption (p < 0.05 compared to the other two groups. The results of the hematological and biochemical parameters showed no significant changes between groups. Histopathological changes compatible with liver toxicity were found in rats treated with noni juice. In conclusion, it was found in this preliminary study that noni juice has positive effects in modulating the development of breast cancer induced by DMBA.
Lei Wang; Hai-Lin Liu; Ya Li; Ping Yuan
AIM: To detect the proteomic variabilities of pancreatic intraepithelial neoplasia (PanIN) and pancreatic carcinoma (PC) induced by 7,12-dimethylbenzanthracene (DMBA) in rat models and to identify potential biomarkers. METHODS: Sixty adult male Sprague Dawley rats were randomized into three groups. The rats had DMBA implanted into their pancreas for one (n = 20) or two months (n = 20) or assigned to the normal group (n = 20). The rats were killed after one or two months, and were evaluated histopathologically. Three tissue samples from each group of rats with either normal pancreas, PanIN (PanIN-2) or PC were examined by 2D-DIGE. The different expression spot features were analyzed by matrix-assisted laser desorption/ionizationtime of flight/time of flight (MALDI-TOF/TOF) tandem mass spectrometry. The expression of enolase 1, a differentially expressed protein, was identified by immunohistochemistry. RESULTS: There was significant difference in the proportions of neoplastic changes between the 1- and 2-mogroups (P = 0.0488). There was an increase in the frequency of adenocarcinomas in the 2-mo group compared with the 1-mo group (P = 0.0309). No neoplastic changes were observed in any of the animals in the normal group. Enolase 1, pancreatic ELA3B, necdin, Hbp23, CHD3, hnRNP A2/B1, Rap80, and Gnb2l1 were up-regulated in the PanIN and PC tissues, and CEL, TPT1, NME2, PCK2, an unnamed protein product, and glycine C-acetyltransferase were down-regulated in the PanIN and PC tissues. The immunohistochemical results showed that enolase 1 expression was up-regulated in the pancreatic cancer tissues of rats and humans. CONCLUSION: The pancreatic protein expression changes induced by DMBA suggest potential molecular targets for the early diagnosis and treatment of PC.
Wang Lu [Pharmacology and Environmental Toxicology, University of Mississippi, University, MS (United States); Camus, Alvin C. [Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA (United States); Dong, Wu; Thornton, Cammi [Pharmacology and Environmental Toxicology, University of Mississippi, University, MS (United States); Willett, Kristine L., E-mail: email@example.com [Pharmacology and Environmental Toxicology, University of Mississippi, University, MS (United States)
CYP1C1 is a relatively newly identified member of the cytochrome P450 family 1 in teleost fish. However, CYP1C1's expression and physiological roles relative to the more recognized CYP1A in polycyclic aromatic hydrocarbons (PAHs) induced toxicities are unclear. Fundulus heteroclitus fry were exposed at 6-8 days post-hatch (dph) and again at 13-15 dph for 6 h to dimethyl sulfoxide (DMSO) control, 5 mg/L benzo[a]pyrene (BaP), or 5 mg/L dimethylbenzanthracene (DMBA). Fry were euthanized at 0, 6, 18, 24 and 30 h after the second exposure. In these groups, both CYP1A and CYP1C1 protein expression were induced within 6 h after the second exposure. Immunohistochemistry (IHC) results from fry revealed strongest CYP1C1 expression in renal tubular and intestinal epithelial cells. Additional fish were examined for liver lesions 8 months after initial exposure. Gross lesions were observed in 20% of the BaP and 35% of the DMBA-treated fish livers. Histopathologic findings included foci of cellular alteration and neoplasms, including hepatocellular adenoma, hepatocellular carcinoma and cholangioma. Strong CYP1A immunostaining was detected diffusely in altered cell foci and on the invading margin of hepatocelluar carcinomas. Lower CYP1A expression was seen in central regions of the neoplasms. In contrast, CYP1C1 was only detectable and highly expressed in proliferated bile duct epithelial cells. Our CYP1C1 results suggest the potential for tissue specific CYP1C1-mediated PAH metabolism but not a more chronic role in progression to liver hepatocellular carcinoma.
Wang, Lu; Camus, Alvin C.; Dong, Wu; Thornton, Cammi; Willett, Kristine L.
CYP1C1 is a relatively newly identified member of the cytochrome P450 family 1 in teleost fish. However, CYP1C1’s expression and physiological roles relative to the more recognized CYP1A in polycyclic aromatic hydrocarbons (PAHs) induced toxicities are unclear. Fundulus heteroclitus fry were exposed at 6–8 days post-hatch (dph) and again at 13–15 dph for 6 hr to dimethyl sulfoxide (DMSO) control, 5 mg/L benzo[a]pyrene (BaP), or 5 mg/L dimethylbenzanthracene (DMBA). Fry were euthanized at 0, 6, 18, 24 and 30 hr after the second exposure. In these groups, both CYP1A and CYP1C1 protein expression were induced within 6 hr after the second exposure. Immunohistochemistry (IHC) results from fry revealed strongest CYP1C1 expression in renal tubular and intestinal epithelial cells. Additional fish were examined for liver lesions eight months after initial exposure. Gross lesions were observed in 20% of the BaP and 35% of the DMBA-treated fish livers. Histopathologic findings included foci of cellular alteration and neoplasms, including hepatocellular adenoma, hepatocellular carcinoma and cholangioma. Strong CYP1A immunostaining was detected diffusely in altered cell foci and on the invading margin of hepatocelluar carcinomas. Lower CYP1A expression was seen in central regions of the neoplasms. In contrast, CYP1C1 was only detectable and highly expressed in proliferated bile duct epithelial cells. Our CYP1C1 results suggest the potential for tissue specific CYP1C1-mediated PAH metabolism but not a more chronic role in progression to liver hepatocellular carcinoma. PMID:20621368
Lingquan Kong; Kainan Wu; Hui Lin
OBJECTIVE To explore the inhibitory effects of quercetin on angiogenesis of experimental mammary carcinoma.METHODS A 7,12-dimethylbenzanthracene (DMBA)-induced animal model of mammary carcinoma was established in rats. Seventy-nine female Sprague-Dawly rats were randomized into 4 groups namely, DMBA, DMBA with tamoxifen (TAM), DMBA with quercetin and control agents identified as group A, B, C and D respectively. Treatment was for 28 weeks. Samples of breast tissues were collected for histopathological observation and microvessel density (MVD) estimation by light microscopy. The expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and the protein product of H-ras were examined by immunohistochemical staining.tumor diameter of group A (76.2%, 2.37cm) were significantly higher than that in group B (40.9%, 1.82cm), C (45.5%, 1.71cm) and D (0%, 0cm) (P＜0.05). There was no significant difference between groups B and C (P ＞0.05), which indicated that quercetin inhibited the incidence and growth of ing for VEGF, bFGF and the H-ras protein product showed significant differences between groups A and B, as well as groups A and C (P ＜ 0.05), but no significant difference between groups B and C (P＞0.05).CONCLUSION Quercetin can reduce the DMBA- induced mammary carcinoma incidence and tumor growth.The following mechanisms may be recausing inhibition of proliferation of the tumor cells and tumor angiogenesis.as VEGF and bFGF, so that angiogenesis in the mammary carcinomas is suppressed, with decreased mammary MVD in the rats receiving quercetin treatment.
许彦枝; 王小玲; 李少成; 李盛琳; 章魁华; 张普洪
Objective The reverting effects of natural carotene on dimethyl-benzanthracene (DMBA) induced oral premalignant lesion in syrian golden hamsters were studied.Methods The hamsters were divided into,control group of the oral premalignant epithelia,oral administration of natural carotene treated group (15mg/kg/day,5d/week,for 4 weeks) and topical application of membrane of natrual carotene treated group (1cm×1cm/10mg,5d/week,for 4 weeks).Results Both oral administration group and topital administration group showed effective,but oral administration group was a bit superior in treating oral premalignant lesion to topical administration.Conclusion Natural carotene could effectively revert DMBA-induced oral premalignant lesion in hamsters.%目的研究天然胡萝卜素对二甲基苯并蒽(DMBA)诱发的金黄地鼠口腔粘膜癌前病变的逆转作用。方法选用DMBA诱发金黄地鼠口腔粘膜癌前病变模型，用0.5%天然胡萝卜素溶液灌胃口服和口腔局部贴膜进行治疗，光镜下组织观察。结果无论是灌胃治疗组还是口腔贴膜组均显示出明显的治疗效果，灌胃治疗组略优于口腔贴膜组。结论天然胡萝卜素对DMBA诱发的动物口腔癌前病变有逆转作用。
Full Text Available Amit Kumar Srivastava,1 Priyanka Bhatnagar,2 Madhulika Singh,1 Sanjay Mishra,1 Pradeep Kumar,2 Yogeshwer Shukla,1 Kailash Chand Gupta1,2 1Proteomics Laboratory, Indian Institute of Toxicology Research (CSIR, Lucknow, India; 2Nucleic Acid Research Laboratory, Institute of Genomics and Integrative Biology (CSIR, Delhi University Campus, India Abstract: In spite of proficient results of several phytochemicals in preclinical settings, the conversion rate from bench to bedside is not very encouraging. Many reasons are attributed to this limited success, including inefficient systemic delivery and bioavailability under in vivo conditions. To achieve improved efficacy, polyphenolic constituents of black (theaflavin [TF] and green (epigallocatechin-3-gallate [EGCG] tea in poly(lactide-co-glycolide nanoparticles (PLGA-NPs were entrapped with entrapment efficacy of ~18% and 26%, respectively. Further, their preventive potential against 7,12-dimethylbenzanthracene (DMBA-induced DNA damage in mouse skin using DNA alkaline unwinding assay was evaluated. Pretreatment (topically of mouse skin with either TF or EGCG (100 µg/mouse doses exhibits protection of 45.34% and 28.32%, respectively, against DMBA-induced DNA damage. However, pretreatment with TF-loaded PLGA-NPs protects against DNA damage 64.41% by 1/20th dose of bulk, 71.79% by 1/10th dose of bulk, and 72.46% by 1/5th dose of bulk. Similarly, 51.28% (1/20th of bulk, 57.63% (1/10th of bulk, and 63.14% (1/5th of bulk prevention was noted using EGCG-loaded PLGA-NP doses. These results showed that tea polyphenol-loaded PLGA-NPs have ~30-fold dose-advantage than bulk TF or EGCG doses. Additionally, TF- or EGCG-loaded PLGA-NPs showed significant potential for induction of DNA repair genes (XRCC1, XRCC3, and ERCC3 and suppression of DNA damage responsive genes (p53, p21, MDM2, GADD45α, and COX-2 as compared with respective bulk TF or EGCG doses. Taken together, TF- or EGCG-loaded PLGA-NPs showed a superior
Christopher J Scarlett
Full Text Available BACKGROUND AND AIMS: Chronic pancreatitis and pancreatic cancer are characterised by extensive stellate cell mediated fibrosis, and current therapeutic development includes targeting pancreatic cancer stroma and tumor-host interactions. Recent evidence has suggested that circulating bone marrow derived stem cells (BMDC contribute to solid organs. We aimed to define the role of circulating haematopoietic cells in the normal and diseased pancreas. METHODS: Whole bone marrow was harvested from male β-actin-EGFP donor mice and transplanted into irradiated female recipient C57/BL6 mice. Chronic pancreatitis was induced with repeat injections of caerulein, while carcinogenesis was induced with an intrapancreatic injection of dimethylbenzanthracene (DMBA. Phenotype of engrafted donor-derived cells within the pancreas was assessed by immunohistochemistry, immunofluorescence and in situ hybridisation. RESULTS: GFP positive cells were visible in the exocrine pancreatic epithelia from 3 months post transplantation. These exhibited acinar morphology and were positive for amylase and peanut agglutinin. Mice administered caerulein developed chronic pancreatitis while DMBA mice exhibited precursor lesions and pancreatic cancer. No acinar cells were identified to be donor-derived upon cessation of cerulein treatment, however rare occurrences of bone marrow-derived acinar cells were observed during pancreatic regeneration. Increased recruitment of BMDC was observed within the desmoplastic stroma, contributing to the activated pancreatic stellate cell (PaSC population in both diseases. Expression of stellate cell markers CELSR3, PBX1 and GFAP was observed in BMD cancer-associated PaSCs, however cancer-associated, but not pancreatitis-associated BMD PaSCs, expressed the cancer PaSC specific marker CELSR3. CONCLUSIONS: This study demonstrates that BMDC can incorporate into the pancreas and adopt the differentiated state of the exocrine compartment. BMDC that
Full Text Available Hua Ye, Kai Yang, Xue-Mei Tan, Xiao-Juan Fu, Han-Xue LiDepartment of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of ChinaBackground: Recent studies have demonstrated that the clock gene PER1 regulates various tumor-related genes. Abnormal expressions and circadian rhythm alterations of PER1 are closely related to carcinogenesis. However, the dynamic circadian variations of PER1 and tumor-related genes at different stages of carcinogenesis remain unknown. This study was conducted to investigate the daily rhythm variation of PER1 and expression of tumor-related genes VEGF, KI67, C-MYC, and P53 in different stages of carcinogenesis.Materials and methods: Dimethylbenzanthracene was used to establish a golden hamster model of buccal mucosa carcinogenesis. Hamsters with normal buccal mucosa, precancerous lesion, and cancerous lesion were sacrificed at six different time points during a 24-hour period of a day. Pathological examination was conducted using routine hematoxylin and eosin staining. PER1, VEGF, KI67, C-MYC, and P53 mRNAs were detected by real-time reverse transcriptase polymerase chain reaction, and a cosinor analysis was applied to analyze the daily rhythm.Results: PER1, VEGF, C-MYC, and P53 mRNA exhibited daily rhythmic expression in three carcinogenesis stages, and KI67 mRNA exhibited daily rhythmic expression in the normal and precancerous stages. The daily rhythmic expression of KI67 was not observed in cancerous stages. The mesor and amplitude of PER1 and P53 mRNA expression decreased upon the development of cancer (P<0.05, whereas the mesor and amplitude of VEGF, KI67, and C-MYC mRNA increased upon the development of cancer (P<0.05. Compared with the normal tissues, the acrophases of PER1, VEGF, and C-MYC mRNA occurred earlier, whereas the acrophases of P53 and KI67 mRNA lagged remarkably in the precancerous lesions. In the cancer stage, the acrophases
Xing-Guo Tan; Zhu-Lin Yang
BACKGROUND: Recent studies have conifrmed that the expression of Ezrin, hepatocyte growth factor (HGF) and its receptor (C-met) is related to the genesis, progress, invasion and metastasis of some malignant tumors. Researches have also found that the biological function of Ezrin is closely related to HGF/C-met in malignant tumors. However, there is no report on the expression levels of Ezrin, HGF and C-met in rat pancreatic cancer induced by dimethylbenzanthracene (DMBA). This study aimed to detect the expression of Ezrin, HGF and C-met in rat pancreatic cancer and non-cancerous pancreatic tissues, and assess its effect in cancer induction by DMBA. METHODS: Ninety Sprague-Dawley rats were divided into 3 groups randomly: 40 in a pancreatic cancer model group (group A), 40 in a trichostatin A (TSA) intervention group (group B), and 10 in a control group (group C). DMBA was directly implanted into the parenchyma of rat pancreas in group A+group B. The rats of group B were treated with 1 ml of TSA saline solution (1μg/ml) via intraperitoneal injection weekly. The carcinogenesis of rats executed within 3-5 months in groups A and B was observed by macrograph and microscopy. Meanwhile, the rats in group C were executed within 5 months. The EnVisionTM immunohistochemistry for detecting the expression levels of Ezrin, HGF and C-met was used in parafifn-embedded sections of the pancreatic specimens. RESULTS: The incidence of pancreatic cancer in group A was 48.6%and in group B 33.3%. The maximal diameter of tumor mass was signiifcantly larger in group A than that in group B (P in the pancreas of group C and other main organs of groups A and B. The positive rates of Ezrin, HGF and C-met were signiifcantly higher in ductal adenocarcinoma than in non-cancerous pancreatic tissues of groups A and B (P0.05). The positive rates of Ezrin, HGF and C-met in non-cancerous pancreatic tissues proved mild to severe atypical hyperplasia of the ductal epithelia. The pancreas of group
张亚平; 杜钢军; 孙婷; 李佳桓; 刘伟杰; 王莹莹
目的 观察附子总生物碱对二甲基苯葸诱导的乳腺癌小鼠体征、部分血液学指标及肿瘤的影响.方法 小鼠分为对照组、模型组、附子总生物碱组.模型组小鼠每天sc二甲基苯蒽橄榄油溶液50 mg/kg,每周2次、连续5周,建立乳腺癌模型,给药组在每天给予二甲基苯蒽的同时,给予附子总生物碱2 mg/kg,观察实验期间各组小鼠乳腺肿瘤的潜伏期、发生率、外观、体温和外耳微循环变化,检测血清中雌二醇和孕酮水平、红细胞Na+,K+-ATP酶和Ca2+,Mg2+-ATP酶活性及血液流变学指标,综合评价附子总生物碱对小鼠乳腺癌的影响.结果 模型组小鼠随给药时间的延长逐渐出现畏寒喜暖、蜷缩少动、体温下降、外耳微循环受阻状况,同时血中雌二醇和孕酮水平升高,红细胞ATP酶活性降低,全血黏度及红细胞聚集指数增高;附子总生物碱可以显著改善上述指标变化,阻止肿瘤生长.结论 二甲基苯葸诱导的乳腺癌小鼠表现为体寒血瘀体征,附子总生物碱能改善这些症状,阻止肿瘤进展.%To investigate the effects of total alkaloids from Aconiti Lateralis Radix Praeparata (TAALRP) on the manifestation of breast cancer induced by 7, 12-dimethylbenzanthracene (DMBA), some hematological indexes, and tumor growth in mice. Methods The mice were divided into control, model, and TAALRP groups. Mice in the model group were sc injected with DMBA (50 mg/kg in olive oil) twice weekly for five weeks to establish a breast cancer model; Mice in TAALRP group were simultaneously ig administrated with TAALRP (2 mg/kg). The changes in tumorigenic latency, incidence, appearance, body temperature, and auricle microcirculation were observed in carcinogenic process; The levels of estradiol and progesterone in serum, the activities of erythrocytic Na+, K+-ATPase and Ca2,Mg2+-ATPase, and hemorrheologic indexes were detected. The effects of TAALRP on breast cancer in mice were
刘乔飞; 廖泉; 牛哲禹; 李媛; 王梦一; 姚鲁田; 卢朝辉; 赵玉沛
Objective To establish the pancreatic cancerogenesis model in mice and to observe the changes of the immune cell populations in peripheral blood and pancreatic lesions.Methods The in situ embedding of canerogen dimethylbenzanthracene (DMBA) was adopted to establish the pancreatic cancerogenesis process from chronic pancreatitis(CP),pancreatic intraepithelial neoplasma (PanIN) to pancreatic cancer.Total ly 60 C57BL/6J mice were used,and 8 weeks after embedding,the mice were killed.20 mice were randomized selected,and 7 immune cell populations in the peripheral blood and pancreatic lesions were detected by flow cytometery(FCM).Results During the observational peroid of 8 weeks,14(23.3％) mice died.Among the 46 survivors,20 mice were randomized selected for FCM analysis.All of the 46 pancreatic lesions were pathologically analyzed.12 cases were CP(26.1％),11 cases were lower grade PanIN (PanIN-1,2,LG-PanIN) (23.9％),9 cases were high grade PanIN (PanIN-3,HG-PanIN) (19.6％) and 14 cases were PC.Among the 20 randomized selected mice,4 cases were CP,7 cases were LG-PanIN,4 cases were HG-PanIN and 5 cases were PC.The myeloid derived suppressor cells (MDSC) of HG-PanIN and CP were significantly more than that of LG-PanIN and CP.In the pancreatic lesions,the granulocytes,MDSC and M2 polarized TAM of HG-PanIN and PC were significantly more than that of LG-PanIN and CP.On the contrary,the T lymphocytes and M1 polarized TAM were significantly decreased.Conclusions In situ embedding of DMBA is a feasible and practical method to establish the spontaneous pancreatic cancerogenesis model in the immunocompetent mice.Pancreatic cancerogenesis can induce systemic and even stronger local immunosuppression,and the MDSC and M2 polarized TAM may play the vital roles.%目的 建立小鼠胰腺癌发生模型并观察外周血及肿瘤组织中免疫细胞群的变化.方法 利用致癌剂二甲基苯蒽(DMBA)胰腺内原位包埋的方法建立从慢性胰腺炎(chronic pancreatitis
Zyflamend对口腔黏膜癌变过程中前列腺素E2和白三烯B4水平影响的动物实验%Detection of prostaglandin E2 and leukotriene B4 in 7,12-dimethyibenz (a) anthracene-induced oral pre-cancerous lesions in hamsters treated with Zyflamend by liquid chromatographic tandem mass spectrometry
目的 通过测定抗炎天然植物混合剂Zyflamend对地鼠口腔黏膜癌变过程中花生四烯酸代谢产物前列腺素( prostaglandin,PG) E2和白三烯B4水平的影响,探讨其可能的作用机制.方法 将27只金黄地鼠分为5组,阴性对照组3只,不涂药；其余24只用0.5％的二甲基苯并蒽( dimethylbenzanthracene,DMBA)涂于左侧颊囊3次/周,3周后将其按随机数字表随机分为4组(每组6只),阳性对照组不涂药,其余3组金黄地鼠分别于左侧颊囊分别涂低、中、高浓度Zyflamend(稀释比例分别为1∶3、1∶1和原液).每周涂药3次,第4周末处死动物取左侧颊囊速冻于液氮中行液相色谱-串联质谱法(liquid chromatographic tandem mass spectrometry,LC-MS/MS)分析.结果 阳性对照组PGE2为(0.377±0.290) μg/g,低、中、高浓度Zyflamend组的PGE2水平分别为(0.523±0.286)、(0.488±0.147)和(0.774±0.314) μg/g,低、中浓度组与阳性对照组相比差异无统计学意义(P＞0.05),高浓度组与阳性对照组相比差异有统计学意义(P＜0.05).与阳性对照组(0.135±0.046) μg/g相比,低、中、高浓度组白三烯B4水平均显著降低(P＜0.05),分别为(0.094±0.066)、(0.096±0.077)和(0.067±0.012) μg/g.结论 癌前病变的早期炎症阶段,Zyflamend能够抑制5-脂氧合酶途径中代谢产物白三烯B4的水平.%Objective To determine the level of prostaglandin E2 (PGE2 ) and leukotriene B4 (LTB4 ) after treatment with a unique anti-inflammatory herbal preparation (Zyflamend) in 7,12-dimethylbenz(a) anthracene (DMBA)-induced oral precancerous lesions in golden Syrian hamsters.Methods The hamsters were divided into five groups.The Syrian hamsters were applied with 0.5％ DMBA solution topically to the left cheek pouch three times per week for three consecutive weeks.The negative control group was not treated.After the last treatment by DMBA,the 0.5％ DMBA treated hamsters were divided into four groups at random.The positive group was
谭雪梅; 叶华; 杨凯; 陈丹; 唐洪
Objective To investigate the expression and circadian rhythm variation of biological clock gene Per1 and cell cycle genes p53,CyclinD1,cyclin-dependent kinases (CDK1),CyclinB1 in different stages of carcinogenesis in buccal mucosa and its relationship with the development of buccal mucosa carcinoma.Methods Ninety golden hamsters were housed under 12 hours light-12 hours dark cycles,and the model of buccal squamous cell carcinoma was established by using the dimethylbenzanthracene(DMBA) to smear the golden hamster buccal mucosa.Before the DMBA was used and after DMBA was used 6 weeks and 14 weeks respectively,the golden hamsters were sacrificed at 6 different time points (5 rats per time point) within 24 hour,including 4,8,12,16,20 and 24 hour after lights onset(HALO),and the normal buccal mucosa,precancerous lesions and cancer tissue were obtained,respectively.HE stained sections were prepared to observe the canceration of each tissue.Real time RT-PCR was used to detect the mRNA expression of Per1,p53,CyclinD1,CDK1 and CyclinB1,and a cosine analysis method was applied to determine the circadian rhythm variation of Per1,p53,CyclinD1,CDK1 and CyclinB1 mRNA expression,which were characterized by median,amplitude and acrophase.Results The expression of Per1,p53,CDK1 and CyclinD1 mRNA in 6 different time points within 24 hours in the tissues of three different stages of carcinogenesis had circadian rhythm,respectively.However,the CyclinB 1 mRNA was expressed with circadian rhythm just in normal and cancer tissue (P＜0.05),while in precancerous lesions the circadian rhythm was in disorder (P＞0.05).As the development of carcinoma,the median of Per 1 and p53 mRNA expression were significantly decreased (P＜0.05),yet the median of CDK1,CyclinB1 and CyclinD1 mRNA expression were significantly increased (P＜0.05).The amplitude of Per1,p53 and CyclinD1 mRNA expression was significantly decreased as the development of carcinoma (P＜0.05),however the amplitude of CDK1 m