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Introduction: DMBA is a chemical carcinogen that induces carcinomas within a few weeks of its application. We developed an experimental model of carcinogenesis induced by DMBA dissolved in 0,5% paraffin oil (DMBA-PO), verifying the inhibitory effect of the carcinogenicity of phenyl isothiocyanate (PhITC), phenethyl (PhnITC) and benzyl isothiocyanate (BITC). Material and Methods: For this, 88 hamsters were distributed into three groups: one exposed to DMBA-PO (Group 1, n=12), three subgroups (n=12) exposed to PhITC, PhnITC, BITC and DMBA-PO (Group 2, n=36) and four control subgroups (n=10) that were not exposed to the carcinogen in which PO (paraffin oil) and isothiocyanates were applied (Group 3, n=40). Results: The experiment had a duration of 20 weeks, at the end of which the inhibitory effect was established by comparing the lesions developed in the groups that received isothiocyanates with the group that was only treated with DMBA-PO. The carcinogenic effect of DMBA-PO is 100% (35 carcinomas) and the inhibitory effect was 0, whereas in the presence of isothiocyanates the carcinogenic effect decreases, with an inhibitory effect of 86% for BITC (5 carcinomas) and 74% for PhITC (9 carcinomas). Conclusion: The inhibitory effect for PhnITC is 80% in relation to invasive OSCC (1 carcinoma).
Introducción: El DMBA es un carcinógeno químico que induce carcinomas a las pocas semanas de su aplicación. Desarrollamos un modelo experimental de carcinogénesis inducida por DMBA disuelto en aceite de parafina al 0,5% (DMBA-Ap) comprobando el efecto inhibidor de la carcinogénesis de los isotiocianatos fenil (PhITC), fenetil (PhnITC) y bencil isotiocianato (BITC). Material y Métodos: Para ello, se distribuyeron 88 hámsteres en 3 grupos: uno expuesto al DMBA-Ap (Grupo 1, n=12), tres subgrupos (n=12) expuestos a PhITC, PhnITC, BITC y DMBA-Ap (Grupo 2, n=36) y cuatro subgrupos controles (n=10), no expuestos al carcinógeno en el que se aplicaron Ap e isotiocianatos (Grupo 3, n=40). Resultados:El experimento tuvo una duración de 20 semanas, al final de la cual se establece de forma comparativa el efecto inhibidor comparando las lesiones desarrolladas en los grupos que recibieron isotiocianatos con respecto al grupo tratado sólo con DMBA-Ap. El efecto carcinógeno del DMBA-Ap es del 100% (35 carcinomas) y el efecto inhibidor 0, mientras que en presencia de isotiocianatos el efecto carcinógeno disminuye, con un efecto inhibidor del 86% para BITC (5 carcinomas) y del 74% para el PhITC (9 carcinomas). Conclusión:El efecto inhibidor del PhnITC es del 80% en relación con el COCE invasivo (1 carcinoma).
Subject(s)
Animals , Male , Anticarcinogenic Agents/therapeutic use , 9,10-Dimethyl-1,2-benzanthracene/toxicity , Carcinogens , Isothiocyanates , Models, Animal , Carcinogenesis , Squamous Cell Carcinoma of Head and NeckABSTRACT
Abstract Aims: To identify the histopathological alterations in organs of Wistar rats to evaluate toxic effects of use of Annonamuricata Raw Leaf Extract (AMRLE) alone or in association with DMBA. Settings and Design: Sixty female Wistar rats were used, separated into groups and treated with a single dose of 65 mg/kg of DMBA and/or with 50; 100 and 200 mg/kg of AMRLE. Hematoxylin-Eosin (HE) and 1% methylene blue stains were used in the histopathological analysis and quantification of Aberrant Crypts (ACs) and Aberrant Crypt Focus (ACF). Fischer and Kruskal Wallis tests were used in the statistical analysis. Results: The administration of 65 mg/kg of DMBA and/or 50, 100 and 200 mg/kg of AMRLE did not influence weight development. Some histopathological alterations (hepatic steatosis; inflammatory foci in the liver, kidney and lung; pulmonary lymphoid hyperplasia, ectasia and hyperplasia in mammary gland epithelium) and the development of ACs and ACF in the intestinal colon were observed in all groups, except in the group negative control, with no statistical difference between analysed groups. Conclusions: Histopathological alterations and the formation of ACs and ACF did not show a statistically significant difference between the groups analysed. However, although AMRLE has antioxidant effects due to the presence of phenolic components, there was still the formation of some pathological processes that may be related to the isolated toxic action of DMBA and/or associated with other components of AMRLE, since these changes were not seen in the negative control group.
Resumen Objetivos: Identificar las alteraciones histopatológicas en órganos de ratas Wistar para evaluar los efectos tóxicos del uso del Extracto de Hoja Cruda de Annona muricata (AMRLE) solo o en asociación con DMBA. Configuración y diseño: Se utilizaron sesenta ratas hembras Wistar, se separaron en grupos y se trataron con una dosis única de 65 mg/kg de DMBA y/o con 50, 100 y 200 mg/kg de AMRLE. Se utilizaron tinciones de hematoxilina-eosina (HE) y azul de metileno al 1% en el análisis histopatológico y la cuantificación de criptas aberrantes (CA) y focus de criptas aberrantes (FCA). En el análisis estadístico se utilizaron las pruebas de Fischer y Kruskal Wallis. Resultados: La administración de 65 mg/kg de DMBA y/o 50, 100 y 200 mg/kg de AMRLE no influyó en el desarrollo del peso. Se observaron algunas alteraciones histopatológicas (esteatosis hepática; focus inflamatórios en el hígado, riñón y pulmón; hiperplasia, ectasia en epitelio de la glándula mamaria e hiperplasia linfoide pulmonar) y el desarrollo de CA y FCA en el colon intestinal en todos los grupos, excepto en el grupo control negativo, sin diferencias estadísticas entre los grupos analizados. Conclusiones: Las alteraciones histopatológicas y la formación de CA y FCA no mostraron diferencias estadísticamente significativas entre los grupos analizados. Sin embargo, aunque AMRLE tiene efectos antioxidantes debido a la presencia de componentes fenólicos, aún existe la formación de algunos procesos patológicos que pueden estar relacionados con la acción tóxica aislada del DMBA y/o asociados con otros componentes de AMRLE, ya que estos cambios no fueron observados en el grupo control negativo.
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Animal models have been providing invaluable contributions to the better understanding of mechanisms of cancer (including leukaemias) development and effectiveness of most of the treatments. Chemical carcinogens are generally used to study the biology of cancers including leukaemias in many animal models, including rats and mice. The studies in most cases are aimed at the development and evaluation of cancer treatments and preventions. Some of the most common chemical carcinogens used in animal models for leukaemias include N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU), dimethyl benz(a)anthracene (DMBA) and benzo(a)pyrene (BaP). This review provides highlights on different animal models of leukaemia induced by the chemical carcinogens mentioned earlier, at the same time discussing the contributions of these models to the leukaemia diagnosis in laboratory animal models for subsequent development of treatment.
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To evaluate the carcinogenicity of p27 knockout (KO) mice with RNA-guided endonuclease (RGENs)-mediated p27 mutant exon I gene (IΔ), alterations in the carcinogenic phenotypes including tumor spectrum, tumor suppressor proteins, apoptotic proteins and cell cycle regulators were observed in p27 (IΔ) KO mice after treatment with 7,12-Dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)(DT) for 5 months. The target region (544~571 nt) in exon I of the p27 gene was successfully disrupted in p27 (IΔ) KO mice using the RGEN-induced non-homologous end joining (NHEJ) technique. After DT exposure for 5 months, a few solid tumors (identified as squamous cell carcinoma) developed on the surface of back skin of DT-treated p27 (IΔ) KO mice. Also, squamous cell hyperplasia with chronic inflammation was detected in the skin dermis of DT-treated p27 (IΔ) KO mice, while the Vehicle+p27 (IΔ) KO mice and WT mice maintained their normal histological skin structure. A significant increase was observed in the expression levels of tumor suppressor protein (p53), apoptotic proteins (Bax, Bcl-2 and Caspase-3) and cell-cycle regulator proteins (Cyclin D1, CDK2 and CDK4) in the skin of DT-treated p27 (IΔ) KO mice, although their enhancement ratio was varied. Taken together, the results of the present study suggest that squamous cell carcinoma and hyperplasia of skin tissue can be successfully developed in new p27 (IΔ) KO mice produced by RGEN-induced NHEJ technique following DT exposure for 5 months.
Subject(s)
Animals , Mice , 9,10-Dimethyl-1,2-benzanthracene , Carcinogenesis , Carcinoma, Squamous Cell , Cell Cycle , Dermis , Epithelial Cells , Exons , Hyperplasia , Inflammation , Phenotype , Skin , Tumor Suppressor ProteinsABSTRACT
Objective To induce skin cancer in BALB/c mice using DMBA as initiator and TPA as tumor promot-er. Through optimizing the doses and frequencies of DMBA administration to establish a stable skin cancer model with less time and causing less skin damage. Methods Shaving the back of mice to expose a piece of skin around 2 cm × 2 cm. The mice were divided into a blank control group and four treatment groups randomly. These four groups were given 1, 2, 4, 7 times 100μg/100μL DMBA/acetone, respectively, in the first week, and twice 4μg/100μL TPA/acetone per week in the next 11 weeks. The body weight changes, time of tumor formation and number of tumors formed were recorded during the experiment. The mice were sacrificed at 12th week and samples of tumor tissue and adjacent normal skin tissue were taken for pathological examination using HE staining. Results Tumors were observed at the 7th week in the group with once DMBA administration in the first week and at the 4th week in the group with twice DMBA administration in the first week. Skin cancers were formed also in the group with 4?time DMBA administration in the first week, however, with signif?icantly more severe skin damages. The mice receiving DMBA everyday in the first week died at the 3th week. Conclusions The best induction protocol for skin cancer in BALB/c mice should be twice DMBA in the first week followed by twice TPA
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Objective To establish a mouse model of cutaneous squamous cell carcinoma induced by 7,12-dimethylbenz(a)anthracene (7,12-DMBA)/croton oil and narrow-band ultraviolet B (NB-UVB) irradiation.Methods A total of fifty 6-8-week old BALB/c mice (male:female 1:1) were randomly divided into three experimental groups.The group A was treated with chemical carcinogens alone, group B was treated with NB-UVB alone, and group C was treated with chemical carcinogens plus NB-UVB.The general status and skin appearance of mice were observed during the experiment.The survival rate and tumor formation rate of each group was calculated at weeks 5, 10, 15, and 20. Pathological examination was carried out to observe the histological changes of skin lesions.Results Papules measuring≥l mm in diameter began to develop in some mice of the group C at 5 weeks after the first treatment with chemical carcinogens.The tumor formation rates at 20 weeks after treatment were 86.67%, 7.14%, 94.12%in the groups A, B, C, respectively.Pathological examination revealed characteristic changes of squamous cell carcinoma in 13.34%, 0%, 70.59%of the mice in the group A, B, C, respectively.Conclusions Establishment of a mouse model of cutaneous squamous cell carcinoma induced by 7,12-DMBA/croton oil and NB-UVB is a better method than treated with chemical carcinogens alone or NB-UVB alone.This method can increase the tumor formation rate and incidence rate of SCC, and within a shorter period.
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Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds consisting of two or more fused aromatic rings. Most of them are formed during incomplete combustion of organic materials such as wood and fossil fuels, petroleum products, and coal. The composition of PAH mixtures varies with the source and is also affected by selective weathering effects in the environment. PAHs are ubiquitous pollutants frequently found in a variety of environments such as fresh water and marine sediments, the atmosphere, and ice. Due to their widespread distribution, the environmental pollution due to PAHs has aroused global concern. Many PAHs and their epoxides are highly toxic, mutagenic and/or carcinogenic to microorganisms as well as to higher forms of life including humans. The main aim of this review is to provide contemporary information on PAH sources, route of exposure, worldwide emission rate, and adverse effects on humans, especially with reference to cancer.
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Aim: Diverse pharmacological and biochemical effects of lupeol have been reported earlier. The present study utilized the immune expression pattern of proliferating cellular nuclear antigen (PCNA), cyclin D1, vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NFkB) to assess the anticancer potential of lupeol in 7,12-dimethylbenz(a) anthracene (DMBA) induced oral carcinogenesis. Methods: Well differentiated squamous cell carcinoma was appeared in the buccal mucosa of hamsters painted with DMBA thrice a week for 14 weeks. The expression pattern of the molecular markers was analysed using immunohistochemistry (PCNA, VEGF), Real Time PCR (NFkB, cyclin D1) and ELISA (COX-2). Results: We noticed oral tumors in all the hamsters treated with DMBA alone and thus the tumor incidence is 100%. The total number of tumors developed in DMBA alone painted hamsters was 23. Upregulation of cell proliferative (PCNA, cyclin D1), inflammatory (NFkB, COX-2) and angiogenic markers (VEGF) was noticed in oral tumor bearing hamsters. Lupeol administration orally to DMBA painted hamsters completely inhibited the tumor formation (0%) and downregulated the immunoexpression pattern of cell proliferative (PCNA, cyclin D1), inflammatory (NFkB, COX-2) and angiogenic markers (VEGF). Conclusion: The present results suggest that lupeol exhibited antitumor potential through its anticell proliferative, anti-inflammatory and anti-angiogenic potential during DMBA induced oral carcinogenesis.
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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.
Hidrocarbonetos policíclicos e aromáticos são carcinógenos usados em modelos experimentais em roedores. Neste estudo, o carcinógeno DMBA (7,12-dimetilbenzantraceno) foi administrado por gavagem, diluído em óleo de milho, para camundongos BALB/c em doses hebdomadárias de 1 mg por animal por 1, 3, 6 ou 9 semanas. Os animais foram pesados e monitorados semanalmente até a morte. Os animais remanescentes foram eutanasiados com a idade de 53 semanas. Na necroscopia, fragmentos representativos das neoplasias foram colhidos e rotineiramente processados para exame histopatológico. De todos os animais que receberam DMBA, 68,57% desenvolveram algum tipo de tumor. Entre os 70 camundongos tratados com diferentes doses de DMBA, 22 (31,43%) desenvolveram neoplasias mamárias. O adenoacantoma foi o tumor mamário mais comumente diagnosticado (18,75%). Pulmões (15,71%), tecido linfoide (11,43%), estômago (7,14%) e pele (2,86%) foram também locais primários de desenvolvimento de neoplasias. Um terço (33,33%) dos camundongos que receberam 1 mg de DMBA desenvolveram neoplasias pulmonares. Portanto, a administração de DMBA foi considerada um modelo eficiente de carcinogênese em camundongos, especialmente para o estudo de neoplasias mamárias, quando a maior dose é utilizada, e de neoplasias pulmonares, quando utilizada a menor dose. Os modelos de carcinogênese química têm sido usados para diversos estudos na pesquisa em câncer, os resultados aqui apresentados mostram novos fatos para um modelo clássico de carcinogênese.
Subject(s)
Animals , Mice , /administration & dosage , Carcinogenesis/chemically induced , Mammary Neoplasms, Experimental/chemically induced , Rats, Inbred Strains/immunology , Polycyclic Aromatic Hydrocarbons/administration & dosage , Neoplasms/veterinaryABSTRACT
Chemoprevention by naturally occurring agents is gaining much attention as a newer dimension in the management of cancer. Many naturally occurring agents have shown cancer chemopreventive potential in a variety of bioassay systems and animal models, having relevance to human disease. Phytic acid or Inositol hexaphosphate (IP6), an antioxidant, is a naturally occurring polyphosphorylated carbohydrate that has shown a strong anticancer activity in several experimental models. We assessed the protective effects of Phytic acid against the 7, 12-dimethylbenz [a] anthracene (DMBA)/ 12-O-tetradecanoylphorbol-13- acetate (TPA) induced mouse skin tumorigenesis at 4 and 16 weeks, the time before and after the tumor development. At molecular level we studied expression and promoter CpG methylation status of p21, DAPK1 and COX-2. Our data suggests exposure of DMBA/TPA methylated the promoter region of p21 and DAPK1 genes in time dependent manner that could be the cause of down regulation of their expression with time, which were reversed by administration of phytic acid. But we did not observe methylation in COX-2 whereas upregulation of COX-2 was observed at protein level in mice treated with DMBA followed by TPA in time dependent manner. Administration of phytic acid prevented theses DMBA/TPA induced molecular changes. Study provides a rationale for cancer chemoprevention by natural occurring compounds like Phytic acid.
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The aim of this study was to assess the effect of oral administration of Hydroalcoholic Extract of Green Propolis (HEGP) on dermal carcinogenesis in rodent model. For the biological assay, we used 36 mice, assigned into 6 groups (n=6): CTR (treated with 100 mg/kg HEGP and no tumor induction), TUM (treated with water and tumor induction), GP10 (treated with 10 mg/kg HEGP and tumor induction), GP50 (treated with 50 mg/kg HEGP and tumor induction) and GP100 (treated with 100 mg/kg HEGP and tumor induction). Cancer induction was performed in the back of the mice by topical application of DMBA. After 16 weeks, mice were euthanized and their backs were submitted to post-mortem histological analysis. The mean number of lesions developed in TUM (4.14±0.89) was significantly higher than in GP10 (2.05±1.02), GP50 (1.8±1.92) and GP100 (2.5±1.73) (p<0.05). The tumors formed in HEGP-treated groups were histologically more differentiated, but only in PV100 in situ lesions were evidenced. Infiltration of anatomical noble structures was less frequent in HEGP-treated groups (p<0.05). Our data suggest that oral administration of HEGP provided partial inhibition of DMBA-induced dermal carcinogenesis, as well as appeared to modulate the differentiation and infiltrative potential of the carcinomas in rodent model.
El objetivo de este estudio fue evaluar el efecto de la administración oral de extracto hidroalcohólico del propóleos verde (HEGP) sobre la carcinogénesis dérmica en modelo de roedores. Para el ensayo biológico, se utilizaron 36 ratones asignados en 6 grupos (n = 6): CTR (tratado con 100 mg/kg HEGP y sin inducción de tumores), TUM (tratada con agua e inducción de tumores), GP10 (tratado con 10 mg/kg HEGP e inducción de tumores), GP50 (tratado con 50 mg/kg HEGP e inducción de tumores) y GP100 (tratado con 100 mg/kg HEGP e inducción de tumores). La inducción de cáncer se llevó a cabo en la región dorsal de los ratones por aplicación tópica de DMBA. Después de 16 semanas, los ratones fueron sacrificados y sus dorsos fueron sometidos a análisis histológico post-mortem. El número medio de lesiones desarrolladas en TUM (4,14±0,89) fue significativamente mayor que GP10 (2,05±1,02), GP50 (1,8±1,92) y gp100 (2,5±1,73) (p<0,05). Los tumores formados en grupos tratados con HEGP fueron histológicamente más diferenciados, pero sólo en PV100 las lesiones in situ fueron manifiestas. La infiltración de las estructuras anatómicas blanco fue menos frecuente en los grupos tratados con HEGP (p<0,05). Nuestros datos sugieren que la administración oral de HEGP proporciona una inhibición parcial de la carcinogénesis dérmica inducida por DMBA, así como pareció modular la diferenciación y potencial infiltrante de los carcinomas en el modelo animal.
Subject(s)
Animals , Mice , Propolis/administration & dosage , Skin Neoplasms/prevention & control , Carcinogenesis/drug effects , Propolis/pharmacology , Propolis/chemistry , Skin Neoplasms/chemically induced , Flavonoids/analysis , Administration, Oral , Chemoprevention , 9,10-Dimethyl-1,2-benzanthracene , Disease Models, Animal , AlcoholsABSTRACT
To evaluate modulatory effects of a hydroalcoholic extract of Brazilian red propolis (HERP) on dermal carcinogenesis using a murine model. METHODS: The HERP was used at concentrations of 10, 50 and 100 mg/kg (PROP10, PROP50 and PROP100, respectively) to modulate dermal carcinogenesis induced by the application of 9,10-dimetil-1,2-benzatraceno (DMBA) on the backs of animals. RESULTS: The chemical compounds identified in HERP included propyl gallate, catechin, epicatechin and formononetin. PROP100 treatment resulted in significantly decreased tumor multiplicity throughout the five weeks of tumor promotion (p<0.05), and this concentration also resulted in the highest frequency of verrucous tumors (p<0.05). All of the tumors that developed in DMBA-treated animals were regarded as squamous cell carcinomas and were either diagnosed as non-invasive verrucous carcinomas or invasive squamous cell carcinomas (SCCs). The average score for malignancy was significantly lower in the PROP100-treated group than the non-treated group (p<0.05), but there was no difference between the other groups (p>0.05). CONCLUSION: The oral administration of hydroalcoholic extract of Brazilian red propolis at a dose of 100 mg/kg had a significant modulatory effect on the formation, differentiation and progression of chemically induced squamous cell carcinoma in a murine experimental model.
Subject(s)
Animals , Rats , Carcinogenesis , Neoplasms/pathology , Propolis/analysis , Rodentia/classificationABSTRACT
Cancer is a cellular tumor that unlike benign tumor can metastasize and invade the surrounding tissues. In the present study the anticancer effect of paclitaxel was evaluated on 7, 12 Di Methyl Benz (a) Anthracene induced skin cancer in wistar rats and results were compared with normal, paclitaxel and paclitaxel-Di allyl sulfide combined alternative chemotherapy. By analyzing the various biochemical parameters (lipid Profile and lipid metabolizing enzymes) and Marker enzymes (squamous cell antigen). Skin cancer was induced in rats by 7, 12 Di methyl benz(a) anthracene (DMBA) at the dosage of 5 μg was dissolved in 100μl and administered into experimental animals for 28 weeks. In this study, we demonstrated that combination of paclitaxel and Di allyl sulfide protects the rats from a lethal dose of DMBA for 30 days. Total cholesterol (TC), free cholesterol (FC), phospholipids (PL) and triglycerides (TG) were found to be significantly increased whereas ester cholesterol (EC) and free fatty acids (FFA) were significantly decreased when compared with cancer bearing group II animals. From the present study, the effect of Paclitaxel- Di allyl sulfide combination proved to be a more significant chemotherapeutic agent against DMBA induced skin cancer in wistar rats compared to that of paclitaxel by analyzing the lipid profile and lipid metabolizing enzymes and marker enzymes.
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Camundongos AIRmax e AIRmin diferem na sensibilidade à carcinogênese, sendo os AIRmin mais sensíveis à carcinogênese de pele devido ao seu fundo genético e um polimorfismo no gene Ahr. Mais que isso, estas linhagens possuem um desequilíbrio de frequência dos alelos do gene Slc11a1. Para estudar a interação dos alelos de resistência (R) ou suscetibilidade (S) do gene Slc11a1 com os loci de resposta inflamatória aguda dos animais AIRmax e AIRmin, foram produzidas sublinhagens homozigotas para estes alelos:AIRmaxRR, AIRmaxSS, AIRminRR e AIRminSS. Nosso objetivo foi investigar a diferença de sensibilidade à carcinogênese de pele induzida por DMBA nestas sublinhagens. A incidência de câncer de pele foi de 7% nos animais AIRminRR e de 13% nos animais AIRminSS.Os animais AIRmaxSS não apresentaram câncer de pele, mas a incidência de câncer em órgãos internos foi 100% nesta sublinhagem.Esses dados mostraram que os camundongos AIRmaxSS tem maior suscetibilidade à carcinogênese, sugerindo que o alelo S, no fundo genético AIRmax, pode influenciar na suscetibilidade ao câncer.
Mice AIRmax and AIRmin differ on sensibility to carcinogenesis. AIRmin mice are significantly more sensitive to skin carcinogenesis than AIRmax mice due to the genetic background and the polymorphism of aryl hydrocarbon receptor (Ahr) gene. Furthermore,these mice have an imbalance of frequency of Slc11a1 gene alleles.To study the interaction of resistant (R) or susceptible (S) Slc11a1 alleles with acute inflammatory reaction loci found in AIRmax and AIRmin mice, homozygous sublines for these alleles were produced: AIRmaxRR, AIRmaxSS, AIRminRR and AIRminSS. The objective of this study was to investigate the difference in skin carcinogenesis sensibility induced by DMBA agent in these sublines.The incidence of skin cancer was 7% in AIRminRR mice and 13% in AIRminSS mice.AIRmaxRR and AIRmaxSS mice did not show skin cancer, but the incidence of internal organs cancer was 100% only in AIRmaxSS mice. These data showed that AIRmaxSS animals have higher susceptibility, suggesting that the S allele in the AIRmax background could influence susceptible to cancer.
Subject(s)
Animals , Mice , Mice , Skin Neoplasms/genetics , Skin Neoplasms/immunology , Carcinogens , Aryl Hydrocarbon Receptor Nuclear Translocator/geneticsABSTRACT
Aim: In present study the antioxidant activity of turmeric was studied in Wistar albino rats. Study design: The experimental animals were divided in to five groups each containing six animals. Group I served as normal control. All the other four groups, viz. II, III, IV and V were first challenged with7-12 Dimethylbenzanthracene (DMBA). Thereafter, group III, IV and V received Indole-3-Carbinol, turmeric and turmeric with garlic respectively for four weeks. Group II have Received no intervention other than DMBA. Methodology: At the end of the study all the animals were sacrificed and the effects of DMBA, Indole-3-Carbinol, Turmeric and Turmeric with garlic were monitored by growth rate during study period and also by assaying the levels of lipid peroxidation (MDA), superoxidedismutase (SOD), and catalase (CAT) in liver and kidney homogenates. In addition serum alanine transferase (ALT), aspartate aminotransferase (AST), alkaline phoshatase (ALP), urea and Creatinine levels were also studied. Results: The results showed that the difference in total body weight gain was not significant among all the groups. Body weight in group II was found to be reduced than the body weight on zero day. There was significant decrease in SOD and CAT, but significant increase in MDA in both the tissue homogenates. The levels of AST, ALT, ALP, Creatinine and Urea were significantly increased in group II. Reversal effects of DMBA were shown by group IV and V but they were lower than group III. Cyst formation in liver was observed in group II rats only. Enlargement and paleness of liver was maximum in group II as compared to other treated groups. Conclusion: In present study the turmeric have shown the reversal effects of DMBA induced carcinogenicity.
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Background & objectives Breast cancer is a leading cause of cancer death in women; dietary fat is the one of the factors that influences its incidence. In the present study we investigated the effect of feeding cow ghee versus soybean oil on 7,12-dimethylbenz(a)anthracene (DMBA) induced mammary cancer in rat and expression of cyclooxygenase-2 and peroxisome proliferators activated receptor- γ (PPAR-γ) in mammary gland. Methods Two groups of 21 day old female rats (30 each) were fed for 44 wk diet containing cow ghee or soybean oil (10%). The animals were given DMBA (30mg/kg body weight) through oral intubation after 5 wk feeding. Another two groups (8 each) fed similarly but not given DMBA served as control for the gene expression study. Results In DMBA treated groups, the animal fed soybean oil had higher tumour incidence (65.4%), tumour weight (6.18 g) and tumour volume (6285 mm3) compared to those fed cow ghee (26.6%, 1.67 g, 1925 mm3, respectively). Tumour latency period was 23 wk on soybean oil compared to 27 wk on cow ghee. Histological analysis of tumours showed that the progression of carcinogenesis was more rapid on soybean oil than on cow ghee. The expression of cyclooxygenase-2 was observed only in DMBA treated rats and it was significantly less on cow ghee than on soybean oil. The expression of PPAR-γ was significantly more on cow ghee than on soybean oil. Interpretation & conclusions Our results show that dietary cow ghee opposed to soybean oil attenuates mammary carcinogenesis induced by DMBA; and the effect is mediated by decreased expression of cyclooxygenase-2 and increased expression of PPAR-γ in the former group.
Subject(s)
Analysis of Variance , Animals , Benz(a)Anthracenes/administration & dosage , Benz(a)Anthracenes/toxicity , Cyclooxygenase 2/metabolism , DNA Primers/genetics , Dietary Fats/pharmacology , Female , Gene Expression Regulation, Neoplastic/drug effects , Mammary Neoplasms, Experimental/chemically induced , Mammary Neoplasms, Experimental/metabolism , PPAR gamma/metabolism , Rats , Reverse Transcriptase Polymerase Chain Reaction , Soybean Oil/pharmacologyABSTRACT
The modulating effect of curcumin and ferulic acid was investigated on expression pattern of apoptosis regulatory p53 and bcl-2 proteins in oral squamous cell carcinoma (OSCC). The OSCC was induced in the buccal pouch of golden Syrian hamster by painting with 0.5% 7,12-dimethylbenz[]anthracene (DMBA) three-times a week for 14 weeks. The expression pattern of p53 and bcl-2 proteins was analyzed by immunohistochemical staining. We noticed 100% tumor formation in hamsters painted with DMBA alone for 14 weeks. Overexpression of p53 and bcl-2 proteins was observed in the buccal mucosa of tumor-bearing hamsters. Oral administration of curcumin (80 mg/kg body wt) and ferulic acid (40 mg/kg body wt) to DMBA painted hamsters on days alternate to DMBA painting for 14 weeks completely inhibited tumor formation and down-regulated the expression pattern of p53 and bcl-2 proteins. Our results thus demonstrated the protective role of curcumin and ferulic acid on DMBA-induced abnormal expression of p53 and bcl-2 proteins in the buccal mucosa of golden Syrian hamsters.
Subject(s)
9,10-Dimethyl-1,2-benzanthracene/toxicity , Animals , Coumaric Acids/pharmacology , Cricetinae , Curcumin/pharmacology , Immunohistochemistry , Male , Mesocricetus , Mouth Neoplasms/chemically induced , Mouth Neoplasms/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Tumor Suppressor Protein p53/metabolismABSTRACT
DMBA (7,12-dimethylbenz[a]anthracene) is known to generate DNA-reactive species during their metabolism, which may enhance oxidative stress in cells. Since selenium is known as a non-enzymic antioxidant, health problems induced by many environmental pollutants, have stimulated the evaluation of relative antioxidant potential of selenium and synthetic organoselenium compounds. Therefore, we aimed to evaluate chemopreventive potential of synthetic organoselenium compounds by monitoring level of liver nitric oxide. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (Se I) and (Se II) in the determined doses. DMBA-induced in rats, the effects of organoselenium compounds on nitric oxide levels in rat liver was studied. In this study, it has been observed a statistically significant increase in (Nitric Oxide) levels for the liver of rat exposed to DMBA (p<0.05). However with administration of Se I and Se II there was a statistically significant decrease in NO levels (p<0.05). The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rat livers was rationalized. Protection against nitric oxide measured in Se I and Se II treated groups were provided by synthesized organoselenium compounds. Se I and Se II both provided chemoprevention against DMBA-induced oxidative stress in rat liver.
ABSTRACT
We investigated the effect of thalidomide on cachexia and TNF-α serum levels during experimental skin carcinogenesis in mice. Female mice were divided into four groups: 1) DMBA (dissolved in acetone) induced tumorigenesis; 2) DMBA and Thalidomide (dissolved in DMSO); 3) DMBA and DMSO; and 4) Acetone. Body weight was measured once a week. Euthanasia was performed 14 weeks later, when blood was collected for the dosage of TNF-α serum levels. Mice with DMBA induced tumorigenesis had a significant loss of body weight when compared to acetone treated animals, starting at the third week and lasting the whole experiment. But there was no difference among Thalidomide treated and the others DMBA control animals, regarding body weight. High TNF-α serum levels were associated with the development of cachexia in mice during the process of experimental skin tumorigenesis. However, there was not a significant difference in the TNF-α serum levels when compared control mice and thalidomide treated mice. These results suggest that thalidomide does not interfere with skin tumorigenesis, cachexia and serum TNF-α levels in Balb/C mice. In addition, high TNF-α serum levels are associated to weight loss during experimental carcinogenesis.
Subject(s)
Animals , Female , Mice , Thalidomide/pharmacology , Cachexia/etiology , Tumor Necrosis Factor-alpha/pharmacology , Carcinogenesis/chemically inducedABSTRACT
A carcinogênese química em glândulas salivares animais não se apresenta como um modelo novo de pesquisa. O uso de DMBA em glândulas submandibulares de ratos produz carcinomas e sarcomas, associados ou não. Apesar de bem estudada a histopatologia deste tipo de carcinogênese, pouco se sabe em relação a imunoistoquímica das neoplasias. Este estudo se propõe a revisar pesquisa pregressa realizada por Mainenti (2006), na tentativa de melhor entender a formação de tumores induzidos por DMBA. O estudo original diagnosticou lesões não neoplásicas, principalmente sialadenites, e tumores como carcinomas, carcinossarcomas e um caso de sarcoma. O presente trabalho fez uso de lâminas e material de estoque em formol. Foram comparadas as lâminas originais com novas lâminas coradas em hematoxilina e eosina. Para a pesquisa de fibras colágenas utilizou-se a coloração pelo método do tricrômico de Gomori. A imunoistoquímica foi realizada utilizando os seguintes anticorpos:AE1/AE3, vimentina, _-SMA, calponina, desmina, miogenina, S-100,CerbB-2 e EMA. Certas lesões, previamente diagnosticadas como sialadenites, foram reclassificadas como carcinomas. A imunoistoquímica foi positiva para os seguintes anticorpos: AE1/AE3 para neoplasia epitelial, vimentina para tecido conjuntivo e tumores mesenquimais, _-SMA e calponina para poucas células fusiformes pleomórficas no estroma dos carcinomas e nas neoplasias mesenquimais. Concluiu-se que a imunoistoquímica revelou diferenciação muito sugestiva de miofibroblastos no estroma dos carcinomas e miofibroblastos compondo o fibrossarcoma e os carcinosarcomas. Estas células produziram colágeno revelado pelo tricrômico de Gomori. O componente epitelial neoplásico foi sugerido como derivado de células luminais.