Research progress of 4-nitroquinoline-1-oxide-induced esophageal squamous cell carcinoma model in mice / 国际肿瘤学杂志

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with a poor prognosis. 4-nitroquinoline-1-oxide (4NQO) is a water-soluble quinoline derivative that can successfully induce the production of squamous cell carcinoma in vivo. Establishing and optimizing experimental methods for 4NQO induced ESCC formation in mice can provide a more suitable in situ model for the study of ESCC.

Ação do curcumin sobre os períodos iniciais da carcinogênese bucal induzida por 4-NQO em modelo murino / Action of curcumin on the initial stages of oral carcinogenesis induced by 4-NQO in a murine model

O Curcumin apresenta potencial terapêutico no tratamento e prevenção de doenças crônicas, inclusive câncer. O objetivo do presente trabalho foi avaliar o impacto do tratamento sistêmico do curcumin sobre os períodos iniciais da carcinogênese bucal induzida pelo 4-NQO em ratos. Quarenta ratos distribuídos em quatro grupos (n=10) foram tratados com solução de 50 ppm de 4-NQO dissolvido na água de beber ad libitum durante todo período experimental, que ocorreu em 8 e 12 semanas, sendo que dois desses grupos foram tratados com 30 ou 100 mg/kg de peso corporal de curcumin diariamente por gavagem oral, e um grupo tratado com veículo no volume correspondente à maior dose de curcumin. Os animais do grupo controle negativo (n=10) foram sacrificados no início do experimento. Os cortes histológicos, provenientes da língua dos animais, foram corados por H&E ou submetidos à reação de imunohistoquímica para detecção de PCNA, Bcl-2, SOCS1 e -3 , e STAT3. Parte das peças foi utilizada para a verificação da expressão de Vimentina, Cdh1, Cdh2 e TWIST1 por RT-qPCR. O tratamento com 100mg/kg de peso corporal de curcumin por 12 semanas, principalmente, diminuiu os valores do H-score de PCNA, Bcl-2, SOCS3, STAT3, enquanto aumentou SOCS1, além de reduzir as atipias celulares observadas na análise morfológica do epitélio lingual. A expressão dos genes avaliados por RT-qPCR também foi reduzida pelo tratamento com curcumin, independentemente da dose utilizada. Os resultados do presente estudo demonstram que o curcumin acaba por intervir e atenuar o desenvolvimento do processo carcinogênico.

Curcumin has therapeutic potential in the treatment and prevention of chronic diseases , including cancer. The aim of this study was to evaluate the impact of systemic treatment of curcumin on the initial periods of oral carcinogenesis induced by 4 - NQO in rats. Forty rats were distributed into four groups (n = 10) and treated with 50 ppm of 4-NQO solution dissolved in the drinking water ad libitum throughout the experimental period, which occurred at 8 and 12 weeks , with two of these groups were treated with 30 or 100 mg / kg body weight daily by oral gavage curcumin, and a group treated with vehicle corresponding to larger dose of curcumin volume. The animals in the negative control group (n = 10 ) were sacrificed at the beginning of the experiment. Histological sections, from the language of animals, were stained with H&E or subjected to immunohistochemical analysis for detection of PCNA, Bcl-2, SOCS1 and -3, and STAT3. Part of the pieces was used to check the expression of vimentin, Cdh1, Cdh2 and TWIST by RT - qPCR . Treatment with 100mg/kg body weight of curcumin for 12 weeks, mainly, decreased the values of the H -score of PCNA, Bcl-2, SOCS3, STAT3 , while increased SOCS1 , and reduce cellular atypia observed in the morphological analysis of lingual epithelium. The gene expression assessed by RTqPCR was also reduced by treatment with curcumin, regardless of the dose used. The results of this study demonstrate that curcumin eventually intervene and attenuate the development of the carcinogenic process

Estudo da carcinogênese bucal experimental utilizando-se o óxido de nitroquinolina (4-NQO) em ratos / Study of experimental oral carcinogenesis using nitroquinoline oxide (4-NQO) in rats

O objetivo do presente trabalho foi validar as alterações teciduais e moleculares durante os estágios iniciais do processo de carcinogênese oral experimental em ratos, utilizando-se 4-NQO. Foram utilizados 20 ratos com aproximadamente 4 meses de idade, aleatoriamente separados em grupos controle (n=10) e tratados com solução de 50 ppm de 4-NQO dissolvido na água de beber (n=10). Os animais do grupo controle foram sacrificados no primeiro dia do experimento e os animais do grupo experimental foram sacrificados após 8 e 12 semanas de tratamento. Os cortes histológicos provenientes da língua foram corados por H&E ou submetidas à reação de imunohistoquímica para detecção de PCNA, Bcl-2, SOCS1 e -3 , e STAT3. Parte dos espécimes foi utilizada para a verificação da expressão de Vimentina, Cdh1, Cdh2 e TWIST1 por RT-qPCR. Os resultados demonstraram que o tratamento com 4-NQO após 8 semanas causou displasia epitelial severa e que houve exacerbação da atipia celular após 12 semanas de tratamento. A positividade dos anticorpos analisados, com exceção do STAT3, foi aumentada em ambos os períodos experimentais. Os resultados do presente estudo apontam que tratamento com 4-NQO por 8 ou 12 semanas viabiliza avaliar as displasias epiteliais experimentais tanto a nível morfológico quanto molecular.

The aim of this study was to validate the tissue and molecular changes during the early stages of experimental oral carcinogenesis in rats, using 4-NQO. Were used 20 rats with approximately 4 months of age, randomly divided into control group (n = 10) and treated with 50 ppm of 4- NQO solution dissolved in drinking water (n = 10). The control group animals were sacrificed on the first day of the experiment and the experimental rats were sacrificed after 8 and 12 weeks of treatment. Histological sections from the tongue were stained with H&E or subjected to immunohistochemistry analysis for detection of PCNA, Bcl ­ 2, SOCS1 and -3, and STAT3. Part of the specimens was used to verify the expression of vimentin, Cdh1, Cdh2 and TWIST1 by RT - qPCR. The results showed that treatment with 4-NQO after 8 weeks caused severe dysplasia and cellular atypia was exacerbation after 12 weeks of treatment. The positivity of antibodies analyzed, with the exception of STAT3 was increased in both experimental periods. The results of this study indicate that treatment with 4-NQO for 8 or 12 weeks enables evaluating experimental epithelial dysplasias both morphological as molecular level

Estimates of DNA damage by the comet assay in the direct-developing frog Eleutherodactylus johnstonei (Anura, Eleutherodactylidae)

The aim of this study was to use the Comet assay to assess genetic damage in the direct-developing frog Eleutherodactylus johnstonei. A DNA diffusion assay was used to evaluate the effectiveness of alkaline, enzymatic and alkaline/enzymatic treatments for lysing E. johnstonei blood cells and to determine the amount of DNA strand breakage associated with apoptosis and necrosis. Cell sensitivity to the mutagens bleomycin (BLM) and 4-nitroquinoline-1-oxide (4NQO) was also assessed using the Comet assay, as was the assay reproducibility. Alkaline treatment did not lyse the cytoplasmic and nuclear membranes of E. johnstonei blood cells, whereas enzymatic digestion with proteinase K (40 !g/mL) yielded naked nuclei. The contribution of apoptosis and necrosis (assessed by the DNA diffusion assay) to DNA damage was estimated to range from 0 percent to 8 percent. BLM and 4NQO induced DNA damage in E. johnstonei blood cells at different concentrations and exposure times. Dose-effect curves with both mutagens were highly reproducible and showed consistently low coefficients of variation (CV < 10 percent). The results are discussed with regard to the potential use of the modified Comet assay for assessing the exposure of E. johnstonei to herbicides in ecotoxicological studies.

Inhibitory Effect of Chinese Herbal Compound Dongju on Tongue Carcinogenesis in Rats / 上海第二医科大学学报

Objective To examine the inhibitory effect of Chinese herbal Compound Dongju on 4-nitroquinoline 1-oxide(4NQO)-induced tongue carcinogenesis in rats. Methods A total of 85 Wistar rats were divided into four groups: model group(n=35),administration group(n=35),normal control group(n=5) and herb control group(n=10).4NQO dissolved in drinking water was administered orally to induce tongue carcinogenesis in rats.The herb compound was injected into the stomach of the rats during oral carcinogenesis.Rats were sacrificed at 9,13,20,24 and 32 weeks from the beginning of the experiment.The tongues of the rats were dissected for gross and histological assessment,and SP immunohistochemical method was also employed to detect the expression of cyclin D1 in the specimens. Results Compared with the model group,the incidence of dysplasia and the positive rate of cyclin D1 were suppressed by Compound Dongju(P

Dectection of p16~(CDKN2A) exon 1 methylation in experimental tongue carcinogenesis in rats / 实用口腔医学杂志

Objective: To detect methylation status of p16 CDKN2A exon 1 during experimental carcinogenesis in rats. Methods:Thirty male clean SD rats were fed with 0.02 g/L of 4-nitroquinoline-oxide (4NQO) in drinking water.13, 16 and 24 weeks after experiment the normal, moderate-severe dysplasia and invasive squamous cell carcinoma tissues were removed from their tongues respectively; then the methylation status of p16 CDKN2A exon 1 were detected by methylation-specific PCR(MSP). Results:A 123 bp-unmethylated product was amplified in all samples but the methylated product was not detected in any of the samples. Conclusion: The p16 CDKN2A exon 1 appeares to be unmethylated during carcinogenesis of tongue cancer in experimental rats.