The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens. OBJECTIVES: The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated. MATERIAL AND METHODS: DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique. RESULTS: From the 27 cases, 9 (33.3%) were HPV-positive and 18 (66.0%) HPV-negative. HPV 18 was the most prevalent viral type (100% cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38). CONCLUSIONS: The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells.

This study investigated the presence of human papillomavirus (HPV) DNA and viral types in 33 cases of oral squamous cells carcinoma (OSCC) and compared the immunohistochemical expression of the cell-cycle markers p21 and pRb between cases of the disease with and without HPV. DNA was extracted from paraffin-embedded tissue and amplified by PCR for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the streptavidinbiotin technique. HPV DNA was detected in 11 (33.33%) of the 33 cases. The prevalent viral type was HPV 18 (81.81%). A significant association was observed between the presence of HPV and immunohistochemical expression of pRb, but not between p21 expression and the presence of the virus. The low frequency of detection of HPV DNA in OSCC suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors.

The aim of the study was to determine the immunohistochemical expression of the PCNA, p53 and bcl-2 proteins in pleomorphic adenomas.onineteen specimens of pleomorphic adenomas were selected for analysis by the streptavidin-biotin-peroxidase method with antibodies againstp53, PCNA and bcl-2 proteins. It was observedweak labeling for p53 in 12 cases (63.1%) andforPCNA in 8 (42.1%). With respect to the bcl-2 labeling index,ono expression of this protein was detected in 12 cases, corresponding to 63.1% of the sample. Based on these findings, it was concluded that p53 and PCNA can favor the proliferative activity of pleomorphic adenomas, whereas bcl-2 probably doesonot effectively particípate in the pathogenesis of this tumor.

El objetivo del estudio fue determinar la expresión inmmunohistoquímica de las proteínas PCNA, p53 y bcl-2 en adenomas pleomórficos. Fueron seleccionados 19 especímenes de adenomas pleomórficos para análisis a través del método de la estreptavidina-biotina-peroxidasa con anticuerpos contra las proteínas p53, PCNA y bcl-2. Fue observada leve marcación para p53 en 12 casos (63,1%) y para PCNA en 8 (42,1%). Con relación al índice de marcación para bcl-2,ono fue detectada en 12 casos (63,1%) expresión de esta proteína. En base a los resultados, se concluyó que las proteínas p53 y PCNA pueden favorecer la actividad proliferativa de adenomas pleomórficos, y por otro lado, la bcl-2 probablementeono participaría efectivamente de la patogenia de este tumor.

INTRODUÇÃO: O cisto odontogênico calcificante (COC) é uma lesão odontogênica de natureza benigna considerada por alguns autores como uma lesão exclusivamente cística, enquanto outros admitem uma contraparte neoplásica benigna. Vários estudos têm pesquisado a natureza das células fantasmas características do COC, porém permanece obscuro o conhecimento sobre a expressão dos constituintes da matriz extracelular (MEC) nessa lesão. OBJETIVO: Realizar uma avaliação imuno-histoquímica da expressão de proteínas constituintes da MEC (fibronectina, tenascina e colágeno I) em espécimes de COCs, a fim de verificar se há diferenças significativas em tal expressão ou se esses padrões representam um espectro da mesma entidade. MATERIAL E MÉTODOS: Foram utilizados dez casos de COCs, representados por cinco do tipo unicístico simples, três do tipo produtor de odontoma e dois com proliferação ameloblastomatosa, que foram submetidos à técnica imuno-histoquímica da estreptoavidina-biotina com anticorpos monoclonais anti-fibronectina, anti-tenascina e anti-colágeno I. RESULTADOS: Verificou-se que houve uma expressão variável das proteínas pesquisadas, tanto entre as lesões do mesmo grupo, como entre os três grupos estudados, sendo notável a reatividade para os três anticorpos apresentada pelas células fantasmas. CONCLUSÃO: Não foi possível observar um padrão de marcação que denotasse diferenças entre o tipo unicístico simples, o produtor de odontoma e o com proliferação ameloblastomatosa. Esse achado reforça a visão de que os vários tipos histológicos do COC podem, simplesmente, representar espectros histológicos diferentes de uma só entidade com comportamento biológico semelhante.

BACKGROUND: The calcifying odontogenic cyst (COC) is an odontogenic lesion of benign nature considered by some authors as an exclusively cystic lesion, while others admit a benign neoplastic counterpart. Some studies have studied the nature of the characteristic ghost cells of the COC. However, the understanding of the expression of the extracellular matrix (MEC) components in this lesion remains unclear. OBJECTIVE: To carry out an immunohistochemical evaluation of the expression of some proteins of the MEC in specimens of COCs, in order to verify wheather there are significant differences in this expression, or these patterns represent a spectrum of the same entity. METHODS: Ten cases of COCs were selected, representing the following diagnosis: Five cases of simple unicystic type, three odontoma producing type and two with ameloblastomatous proliferating type. The specimens were processed for immunohistochemical staining by the streptavidin-biotin method with monoclonal antibodies anti-fibronectin, tenascin and collagen I. RESULTS: A variable expression of the proteins studied was verified, not only in the lesions of the same group, but also among the three studied groups. There was a notable reactivity for the three antibodies in ghost cells. CONCLUSION: It was not possible to observe a characteristic staining profile that denoted differences between the simple unicystic type, the odontoma producing type and the ameloblastomatous proliferating type. This finding supports the concept that the histologic types of the COC might represent different specters of the same entity with similar biological behavior.