The promoting effect of carbamide peroxide teeth bleaching gel in a preclinical model of head and neck cancer in hamster buccal pouch.

Autor:	Faccin Bampi V; Laboratory of Medical Skills and Surgical Research, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil., Ferreira Vilela W; Department of Food Sciences, Federal University of Lavras, Lavras, Brazil., Vilela Gonçalves R; Department of Morphology Science, Federal University of Pelotas, Pelotas, Brazil., Tavares Rheingantz MG; Department of Morphology Science, Federal University of Pelotas, Pelotas, Brazil., Minello LF; Department of Morphology Science, Federal University of Pelotas, Pelotas, Brazil., Braga da Silva JL; Department of Surgery, Faculty of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil., Oliveira de Oliveira LB; Department of Morphology Science, Federal University of Pelotas, Pelotas, Brazil.
Jazyk:	angličtina
Zdroj:	Clinical and experimental otorhinolaryngology [Clin Exp Otorhinolaryngol] 2014 Sep; Vol. 7 (3), pp. 210-5. Date of Electronic Publication: 2014 Aug 01.
DOI:	10.3342/ceo.2014.7.3.210
Abstrakt:	Objectives: The aim of this study was to verify the promoting effect of carbamide peroxide on dimethylbenzanthracene (DMBA)-induced carcinogenesis in the hamster buccal pouch, in order to reduce the period of latency for tumor formation. Methods: Sixteen hamsters were randomized into two groups of eight animals each. The hamsters of the group I had their right buccal pouches treated with 0.5% DMBA and 10% carbamide peroxide teeth bleaching gel for 55 days. The animals of the group II had their right pouches treated only with DMBA. After, six animals of each group had their pouches prepared for light microscopy. Histomorphometry was performed to assess the presence of keratinization, nuclear polymorphism, pattern of invasion, number of blood vessels, and inflammatory infiltrate in the tumor front. Furthermore, the newly formed lesions were graded according the Bryne's grading system. The remaining animals had the vascular system of the pouches casted by Mercox and qualitatively analyzed by scanning electron microscopy. Results: Histopathological analysis of the buccal pouches treated with DMBA and carbamide peroxide exhibited formation of squamous cell carcinoma well-differentiated with a high degree of malignancy in all pouches. The development of this neoplasm was associated with a significant increase in the number of blood vessels, presence of keratin pearls, and inflammatory infiltrate. The pouches of the group II showed inflammation, epithelial hyperplasia, dysplasia, and squamous cell carcinoma in only three right pouches. The analysis of the electron micrographs of the pouches chemically inducted with DBMA and carbamide peroxide reveled formation of a new vascular network characteristic of squamous cell carcinoma. Conclusion: The protocol presented here, using DMBA associated with carbamide peroxide, shortens the period of latency to produce squamous cell carcinoma in the hamster buccal pouch, decreasing the time and costs of the experiments.
Databáze:	MEDLINE
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