Expression of odontogenic ameloblast-associated protein, amelotin, ameloblastin, and amelogenin in odontogenic tumors: immunohistochemical analysis and pathogenetic considerations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Osteolipoma of the buccal mucosa

Lipomas are benign mesenchymal neoplasms of soft tissue that can be found in any part of the human body. Conversely, their presence in the oral mucosa is rather uncommon, with approximately 4% of the cases occurring in the oral cavity. In such cases, they are likely to have originated from mature adipose tissue and to be among several described histological variants of lipomas, which are identified according to the predominant type of tissue. There is a rare lipoma, known as an osteolipoma or an ossifying lipoma; however, little has been written this type of lipoma characterized by a classical lipoma with areas of osseous metaplasia. Considering the few cases of oral osteolipomas previously described in the English-related literature and the consequent risk of misdiagnosis and overtreatment, this paper describes an extreme case of an osteolipoma affecting the buccal mucosa of an adult patient. This paper focuses particularly on the pathogenesis of this lesion and the discussion of a correct diagnosis.

Markers of tumors susceptibility in head and neck cancer

Genetic polymorphisms are associated with a number of enzymes involved in the induction of head and neck carcinomas. It has been suggested that such polymorphisms may be linked to cancer susceptibility. Using a control-case study molecular genetic approach, we have investigated the association between polymorphisms genes (CYPs, GSTs and NAT2 genes) and susceptibility in head and neck cancer.

DNA methylation patterns of the CDHI, RARB, and SFN genes in choroid plexus tumors

Genetic and epigenetic alterations in choroid plexus tumors, a rare neuroepithelial neoplasm most frequently detected in children, are poorly characterized. Epigenetic silencing associated with aberrant CpG island methylation is one mechanism leading to the loss of tumor suppressor functions in cancer cells. Using methylation-specific polymerase chain reaction, the methylation patterns of the genes CDH1 (E-cadherin), RARB (retinoic acid receptor, beta), and SFN (stratifin; 14-3-3 sigma) were retrospectively investigated in eight choroid plexus tumors (five papillomas, two atypical papillomas, and one carcinoma), as well as in two normal cortexes obtained after autopsy from male individuals aged 6 months and 64 years. Among the six pediatric tumors, the mean age at diagnosis was 1.8 years old (range, 0.2-6) and the two adult tumors were detected in a 66-year-old man and a 45-year-old woman. A high frequency of hypermethylation was detected in CDH1 and SFN genes in tumoral and normal cortex tissues. Tumor-specific RARB hypermethylation was observed in four papillomas. Further studies are required to evaluate the role of aberrant methylation in choroid plexus tumor progression. (c) 2007 Elsevier B.V. All rights reserved.

Effects of ginger (Zingiber officinale Roscoe) on DNA damage and development of urothelial tumors in a mouse bladder carcinogenesis model

Extracts of the spice ginger (Zingiber officinale Roscoe) are rich in gingerols and shogaols, which exhibit antioxidant, anti-inflammatory, antifungal, anti mycobacterial, and anticarcinogenic proprieties. The present study evaluated the chemoprotective effects of a ginger extract on the DNA damage and the development of bladder cancer induced by N-butyl-N-(4-hydroxibutyl) nitrosamine (BBN)/N-methyl-N-nitrosourea (MNU) in male Swiss mice. Groups G1-G3 were given 0.05% BBN in drinking water for 18 weeks and four i.p. injections of 30 mg/kg body weight MNU at 1, 3, 10, and 18 weeks. Group G4 and G5 received only the BBN or MNU treatments, respectively, and groups G6 and G7 were not treated with BBN or MNU. Additionally, Groups G2, G3, and G6 were fed diets containing 1, 2, and 2% ginger extract, respectively, while Groups G1, G4, G5, and G7 were fed basal diet. Samples of peripheral blood were collected during the experiment for genotoxicity analysis; blood collected 4 hr after each MNU dose was used for the analysis of DNA damage with the Comet assay (assay performed on leukocytes from all groups), while reficulocytes collected 24 hr after the last MNU treatment of Groups G5-G7 were used for the micronucleus assay. At the end of the experiment, the urinary bladder was removed, fixed, and prepared for histopathological, cell proliferation, and apoptosis evaluations. Ginger by itself was not genotoxic, and it did not alter the DNA damage levels induced by the BBN/MNU treatment during the course of the exposure. The incidence and multiplicity of simple and nodular hyperplasia and transitional cell carcinoma (TCC) were increased by the BBN/MNU treatment, but dietary ginger had no significant effect on these responses. However, in Group G2 (BBN/MNU/2% ginger-treated group), there was an increased incidence of Grade 2 TCC. The results suggest that ginger extract does not inhibit the development of BBN-induced mouse bladder tumors.

Epigenetic Silencing of CRABP2 and MX1 in Head and Neck Tumors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression of Ki-67 Antigen and Caspase-3 Protein in Benign Lesions and Esophageal Carcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differentially expressed genes in giant cell tumor of bone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ameloblastic fibro-odontoma: A case report

Ameloblastic fibro-odontoma (AFO) is a rare, benign, slow-growing odontogenic tumor, generally asymptomatic and more prevalent in children and adolescents. We report a case of AFO in the mandible of an eight-year-old Caucasian male patient, and review the literature. Intraoral examination revealed a swelling extending from the deciduous second molar to the retromolar triangle, covered with normal mucosa. A panoramic radiograph showed a large, well-demarcated radiolucency with radiopaque areas. The provisional diagnosis was of AFO, and so an incisional biopsy was performed. Histologically, the lesion was composed of connective tissue resembling the dental papilla, with epithelial strands or islands, as well as denticles and amorphous masses of enamel and dentin consistent with a diagnosis of AFO. Surgical excision and curettage of the lesion were performed. The patient has been monitored for eight years and the lesion has not recurred.

Comparison of histological and molecular diagnosis of Helicobacter pylori in benign lesions and gastric adenocarcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Wound healing and colon carcinogenesis. Enhancing effects of skin wounding on development of colon tumors induced by 1,2 Dimethylhydrazine in the rat

Este estudo foi desenvolvido com a finalidade de investigar a possível influência do processo de cicatrização sobre o desenvolvimento neoplásico à distância, em um modelo experimental de carcinogênese do colon induzido pela 1,2 dimetil-hidrazina ( DMH). Ratos Wistar machos receberam injeções semanais de DMH ( 20mg/Kg, via subcutânea) ou solução salina, durante oito semanas. Na nona semana, um grupo tratado com DMH e um controle, foram submetidos à intervenção cirúrgica para retirada de um retalho cutâneo de 4cm no flanco direito, que cicatrizou por segunda intenção. Na 12ª semana, logo após o fechamento da ferida cutânea, os animais foram submetidos à eutanásia. O colon foi dividido em segmentos proximal e distal e examinado a nível macroscópico e histológico. Foram analisadas a incidência, distribuição e morfologia das lesões. O número total de tumores na mucosa do colon e o número de tumores por animal foi significantimente maior no grupo submetido à ferida cutânea do que no grupo tratado somente com DMH. O número de carcinomas pouco diferenciados foi significantimente maior no grupo com ferida cutânea do que em seu respectivo controle. Estes resultados sugerem que o processo de reparação de uma ferida cutânea favorece o desenvolvimento neoplásico em um órgão à distância, tal como o colon e que este efeito parece estar relacionado ao tipo histológico da neoplasia.

Câncer diferenciado da tiróide de baixo risco: revisão do estado atual da literatura e proposta de conduta

A incidência do câncer diferenciado da tiróide vem aumentando há várias décadas no Brasil, assim como em todo o mundo. A popularização de métodos diagnósticos sensíveis e de uso relativamente simples tem contribuído para o diagnóstico cada vez mais freqüente de carcinomas de pequeno tamanho. Uma parte destes tumores ocorre em pacientes denominados de baixo risco, que poderiam se beneficiar de estratégias de conduta menos agressivas. Entretanto, a definição de baixo risco ainda é confusa e não existem meios seguros para distinguir os pacientes que evoluirão de forma pior dos demais. Por outro lado, o uso de novos métodos de acompanhamento vem mudando a maneira de conduzir estes casos. Um grupo multidisciplinar que inclui pesquisadores básicos, endocrinologistas, médicos nucleares, cirurgiões e patologistas endócrinos reviu a literatura pertinente e, com base em sua experiência, propõe algumas normas de conduta no carcinoma diferenciado da tiróide chamado de baixo risco em nosso meio.

Three-dimensional magnetic resonance reconstruction images before and after surgical therapy of spontaneous canine brain tumors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosomal imbalances detected in primary bone tumors by comparative genomic hybridization and interphase fluorescence in situ hybridization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)