Transformación de leucoplasia verrugosa proliferativa en carcinoma oral: diez años de seguimiento

The authors present a case of proliferative verrucous leukoplakia (PVL) in a 78-year-old man. It was initially presented as leukoplakia on the tongue but a microscopic investigation in 1991 revealed it to be a mild epithelial dysplasia. After 5 years of follow-up, the lesion presented changes in size and location, and a recidivant behavior. In 1996, a red granular and indurated area that appeared on the tongue was found to be a microinvasive squamous cell carcinoma when microscopically investigated. After a review of the clinicopathologic behavior of this entity, the authors concluded that it was a typical PVL, whose diagnosis is difficult and retrospective, as indicated by others. The authors emphasize the importance of periodic detailed clinical and histological examination of this type of lesions in order to detect early signs of malignancy.

Expression of betacatenin in carcinoma in pleomorphic adenoma, pleomorphic adenoma and normal salivary gland: an immunohistochemical study

OBJECTIVES: Pleomorphic adenomas are the most frequent type of epithelial salivary gland neoplasms, and their malignant counterpart, the carcinoma in pleomorphic adenomas, is much less common. Beta-catenin is a cell adhesion molecule associated with the invasion and metastasis of carcinomas of the head and neck, esophagus. The objective of this study was to detect the expression of beta-catenin in pleomorphic adenomas, carcinomas in pleomorphic adenomas and normal salivary glands to discuss its role in the development of these two lesions. STUDY DESIGN: The expression of beta-catenin (BD Transduction Laboratories) was analyzed by immunohistochemistry in formalin-fixed, paraffin embedded specimens by the avidin-biotin-peroxidase complex method in 16 pleomorphic adenomas (12 from minor salivary glands), 3 carcinomas in pleomorphic adenomas (all from palate) and 10 normal salivary glands as control group (5 from major and 5 from minor salivary glands). RESULTS: All cases of glands, adenomas and carcinomas in pleomorphic adenomas have membranous and cytoplasmic immunostaining. Nuclear beta-catenin immunostaining was not observed. The antibody presented a fine granular arrangement in the cytoplasm and cellular membrane of duct and acinic cells. Higher beta-catenin index rates were seen mainly in salivary gland ducts and in ductal structures in the adenomas and carcinomas in pleomorphic adenomas. There was protein loss in pleomorphic adenomas and cytoplasmic accumulation in carcinoma in pleomorphic adenomas. CONCLUSIONS: The present study showed participation of the loss of beta-catenin adhesion molecule in the development of pleomorphic adenoma, and that the cytoplasmic accumulation of the molecule takes part in the malignant transformation of the pleomorphic adenoma into carcinoma in pleomorphic adenoma.

Quantitative cell-cycle protein expression in oral cancer assessed by computer-assisted system

The knowledge of cell-cycle control has shown that the capacity of malignant growth is acquired by the stepwise accumulation of defects in specific genes regulating cell growth. Histologic diagnosis might be improved by a quantitative evaluation of more specific diagnosis biomarkers, which could help to precisely identify pre-malignant and malignant oral lesions. The aim of the present study is to evaluate whether computer-based quantitative assessment of p53, PCNA and Ki-67 immunohistochemical expression, could be used clinically to foresee the risk of oral malignant transformation. This retrospective study was carried out in ninety-five oral biopsies, 27 were classified as fibrous inflammatory hyperplasia, 40 as leukoplakia and 28 as oral squamous cell carcinoma. Sixteen out of the 40 leukoplakia were diagnosed as non-dysplastic leukoplakia, the other 24 being dysplastic leukoplakia, of which 50.0% were classified as moderate to severe dysplasia. Comparison of the four groups of oral tissues showed significant rises in p53 and Ki-67 positivity index, which increased steadily in the order benign, pre-malignant, and malignant. In contrast, it was not possible to relate higher PCNA levels with pre-malignant and malignant oral lesions. We therefore conclude that PCNA immunohistochemistry expression is probably an inappropriate marker to identify oral carcinogenesis, whereas joint quantitative evaluation of p53 and Ki-67, appears to be useful as a tumor marker, providing a pre-diagnostic estimate of the potential for cell-cycle deregulation of the oral proliferate status.

Immunohistochemical expression of PCNA, p53, bax and bcl-2 in oral lichen planus and epithelial dysplasia.

The potential for malignant transformation of oral lichen planus is still controversial. The expression of proteins related to cell proliferation and apoptosis in oral lichen planus and epithelial dysplasia was analyzed to evaluate the true potential for malignant transformation of this disease. Twenty-four cases of each lesion were subjected to the streptoavidin-biotin technique for identifying the immunohistochemical expression of PCNA, p53, bax, and bcl-2 proteins. Of the 24 cases of oral lichen planus, 14 (58.33%) were positive for PCNA, 10 (41.67%) for p53, 4 (16.67%) for bcl-2 and 12 (50%) for bax, whereas of the 24 cases of epithelial dysplasia, 20 (83.33%) were positive for PCNA, 10 (41.67%) for p53, 6 (25%) for bcl-2, and 20 (83.33%) for bax. Chi-squared test showed no statistically significant differences between the expression of p53 and bcl-2 in oral lichen planus and epithelial dysplasia, regardless of the grade (P > 0.05). However, the expression of PCNA and bax was significantly increased in epithelial dysplasia (P < 0.05). The results of this study showed that alterations in expression of these proteins are observed in oral lichen planus and epithelial dysplasia, suggesting the potential for malignant transformation in both lesions.

Papel da proteína Mx1 na resposta a interferons e no processo neoplásico

The Mx1 protein is encoded by an interferon- induced gene and shares domain organization, homooligomerization capacity and membrane association with the large dynamin-like GTPases. The Mx1 protein is involved in the response to a large number of RNA viruses, such as the bunyavirus family and the influenza virus. Interestingly, it has also been found as a methylation-silenced gene in several types of neoplasm, including head and neck squamous cell carcinoma. In this scenario, MX1 gene silencing is associated with immortalization in several neoplastic cell lines. Thus, Mx1 stands out as one of the key proteins involved in interferon-induced immune response and also plays an important role in cell cycle control. Here we discuss some of the functions of the Mx1 protein, including its antiviral activity, protein folding and involvement in neoplasia, as well as those revealed by investigating its cellular partners.

Evaluation of the expression of p53, MDM2, and SUMO-1 in oral lichen planus

Objective: The objective of this study was to compare the expression of proteins p53, MDM2, and SUMO-1 in oral lichen planus (OLP) lesions, epithelial dysplasia, and squamous cell carcinoma. Materials and Methods: The sample consisted of the following five groups of cheek mucosa lesions: normal mucosa (NM), inflammatory fibrous hyperplasia (IFH), lichen planus, epithelial dysplasia, and squamous cell carcinoma. The tissue samples were stained with hematoxylin-eosin and submitted to immunohistochemistry using anti-p53, anti-MDM2, and anti-SUMO-1 antibodies. Results: The results of this study demonstrated similar expression of p53 and MDM2 between OLP, oral epithelial dysplasia and, to a lesser extent, between OLP and oral squamous cell carcinoma (OSCC). However, for SUMO-1 a similar expression was observed in OLP, NM, and IFH. Conclusions: The results demonstrated overexpression of important proteins (p53 and MDM2) related to regulatory mechanisms of apoptosis in OLP, suggesting that there is a favorable environment for malignant transformation. The expression of SUMO-1 in OLP was similar to NM and IFH, suggesting that alterations of this protein occur at later stages of carcinogenesis, because important overexpression occurred in oral epithelial dysplasia and OSCC. © 2013 John Wiley & Sons A/S.

Digit ratio (2D:4D) is associated with gastric cancer

Background: Sex steroid exposure during early human development may influence disease susceptibility. Digit ratio (2D:4D) is a putative marker for prenatal hormone exposure and sensitivity, as well as the action of genes closely related to carcinogenesis. Digit ratio could act as a possible marker for cancer predisposition. Aims: The aim of this study is to investigate the possible correlations between right hand, left hand and right minus left (R. - L) 2D:4D and gastric cancer (GCA) in men and women and assess the correlations with tumor staging and histological diagnosis. Methods: Digital images of the right and left hand palms of patients diagnosed with GCA (n = 57, 42 males, 15 females) and age and sex-matched controls (n = 59, 41 males, 18 females) were obtained. Means for 2D:4D were compared. Data were analyzed by repeated-measures one-way ANOVA and Student's t-test for finger measurements and group comparisons and Pearson's and Spearman's tests for correlations with tumor staging (α = 0.05). Results: GCA group presented significantly higher left 2D:4D, but significantly lower R. - L in comparison to healthy controls, particularly so for males. Digit ratio did not correlate to clinical staging or TNM staging. However, low R. - L was significantly related to adenocarcinomas. Conclusions: Early developmental conditions, including prenatal testosterone seem to play a role on the malignant transformation of gastric lesions. The 2D:4D pattern found for gastric cancer parallels that earlier described for breast cancer. The findings suggest that 2D:4D could add to the list of etiological factors and be a putative marker for the screening of patients' susceptibility to develop gastric cancer. © 2012 Elsevier Ltd.

Análise clínico-histológica da queilite actínica: uma abordagem interexaminadores e correlação de áreas atróficas e não atróficas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise comparativa entre terapia fotodinâmica com ácido 5-aminolevulínico versus crioterapia no tratamento da queratose actínica: estudo prospectivo randonizado

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Expressão do PCNA e p53 em leucoplasias de mucosa jugal com diferentes graus de queratinização (Graus I, II, e III de Grinspan)

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

Avaliação da expressão das proteínas p53, MDM2 e SUMO-1 em líquen plano bucal, displasia epitelial bucal e carcinoma de células escamosas bucal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação da seqüência de cDNA da enzima hialuronidase do veneno de Polybia paulista (Hymenoptera : vespidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Expressão de HER-1 e HER-2 totais e fosforilados em queilite actínica e carcinoma epidermóide de lábio inferior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo do potencial de transformação maligna do líquen plano bucal: análise histológica, histoquímica e imunoistoquímica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação da constante de afinidade e cinética da interação lectina ArtinM-célula leucêmica (NB4) por meio de técnicas piezoelétrica e eletroquímica

Pós-graduação em Biotecnologia - IQ