Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

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

Human papillomavirus in oral squamous cells carcinoma in a population of 75 Brazilian patients

Purpose In the present study, we investigated the presence of human papillomavirus (HPV) DNA and viral types in 75 cases of oral squamous cells carcinoma from Brazil to obtain data that would contribute to a better understanding of the role of HPV in the pathogenesis of this tumor. Materials and methods DNA was extracted from paraffin-embedded tissue and amplified by polymerase chain reaction using a pair of primers designated PCO3+ and PCO4+ for the detection of a fragment of the human β-globin gene, followed by polymerase chain reaction for the detection of HPV DNA using a pair of generic primers, GP5+ and GP6+. Viral typing was performed by dot blot hybridization. Results Human papillomavirus DNA was detected in 18 (24%) of the 75 cases positive for the human β-globin gene. No significant association was observed between HPV and age, sex, or anatomical location of the tumor. The most prevalent viral type was HPV-18 (77,8%). Conclusion The low frequency of detection of HPV DNA in oral epidermoid carcinomas suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors

Detection of HPV DNA and immunohistochemical expression of cell cycle proteins in oral carcinoma in a population of brazilian patients

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

Expressão imuno-histoquímica de proteínas da matriz extracelular em cistos odontogênicos calcificantes

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