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 percent) of the 33 cases. The prevalent viral type was HPV 18 (81.81 percent). 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.

Ki-67 cell proliferation in familial and in esporadic unilateral retinoblastoma: case report

PURPOSE: Ki-67 is a nuclear protein that is expressed at all phases of the cell cycle except the resting phase. This study is a clinicopathologic observational case report that aims to report on the cell proliferation rates, as measured by the Ki-67 antigen, in two enucleated retinoblastoma eyes. METHODS: One unilateral familial (mother with unilateral disease - patient 1) and one unilateral sporadic retinoblastoma (patient 2) patients were submitted to enucleation without previous treatment. The tumor cell proliferation rate was assessed by the Ki-67 antigen labeling index (stained cells / 100 cells) in five different fields of the tumor. RESULTS: Patient 1 was 23 months old and the tumor was exophytic with associated neovascularization of the iris; patient 2 was 6 years old and the tumor was endophytic with coarse vitreous seeds. Both enucleated eyes presented optic nerve with free surgical margins. Positive Ki-67 cell index in patient 1 varied from 75 to 90 (MD ± SD: 79.5 ± 6.61) and in patient 2 from 38 to 60 (MD ± SD: 46.6 ± 8.2). CONCLUSIONS: The familial retinoblastoma, besides the earlier age presentation, showed 45.8 percent more Ki-67 positive cells than the same stage sporadic one. This proliferation rate may explain the earlier presentation age of the tumor in the inherited disease.

OBJETIVO: O Ki-67 é antígeno nuclear que se expressa em todas as fases do ciclo celular, exceto no período de repouso. Este é um estudo de casos com correlação clínico-patológica que visa avaliar a taxa de proliferação celular, medida pelo antígeno Ki-67, em 2 olhos enucleados com retinoblastoma. MÉTODOS: Um paciente com retinoblastoma unilateral familiar (mãe com doença unilateral - paciente 1) e outro com retinoblastoma unilateral esporádico (paciente 2) foram submetidos à enucleação ocular sem outro tratamento prévio. A taxa de proliferação celular foi avaliada segundo índice obtido pela contagem de células marcadas com Ki-67, em 5 campos sob microscópia óptica (células marcadas/100 células). RESULTADOS: O paciente 1, com 23 meses de idade, apresentou tumor exofítico com neovascularização de íris associada; o paciente 2, de 6 anos, apresentou tumor de crescimento endofítico, com sementes vítreas importantes. Ambos os olhos enucleados apresentaram margens cirúrgicas do nervo óptico livres de neoplasia. O índice de células positivas no paciente 1 variou de 75 a 90 (Média ± DP: 79,5 ± 6,61), e no paciente 2, de 38 a 60 (Média ± DP: 46,6 ± 8,2). O retinoblastoma familiar, além de sua manifestação em idade mais precoce, apresentou 45,8 por cento mais células positivas que o retinoblastoma esporádico com o mesmo estadiamento. CONCLUSÃO: O retinoblastoma familiar, além de surgimento mais precoce, apresentou 45,8 por cento mais células em proliferação que o retinoblastoma esporádico em mesmo estádio. Essa taxa de proliferação pode explicar a menor idade de aparecimento do tumor nos casos de doença herdada.

Canine biphasic synovial sarcoma: case report and immunohistochemical characterization

The clinical, radiological and pathologic features of a biphasic synovial sarcoma in the left elbow joint of a two-year-old male Rottweiler are presented. The tumor showed positive immunoreactivity for vimentin, Epithelial Membrane Antigen (EMA), p53 and PCNA, while it was negative for the cytokeratin used, S-100, Rb and p21. Immunohistochemistry for EMA allowed the identification of epithelioid components of synovial sarcoma, and may, therefore, contribute in establishing a diagnosis of biphasic synovial sarcoma. Intratumoral variation in PCNA immunoreactivity was minimal, indicating that the various tumor components proliferate at more or less similar rates. Overall, the characterized immunohistochemical profile for canine synovial sarcoma, not defined previously, may provide clues to the histogenesis of the phenotypically mesenchymal and epithelial elements of the tumor, and may be of value in the differential diagnosis of challenging cases, decreasing the risk of under- and mis-diagnosis. Although more cases need to be studied to determine whether there is a consistent pattern of immunostaining in canine synovial sarcoma, its potential significance is discussed in relation to the histogenesis, molecular pathology and differential diagnosis of canine synovial sarcoma.

Expression of the G1-S Modulators in Hepatitis B Virus-Related Hepatocellular Carcinoma and Dysplastic Nodule: Association of Cyclin D1 and p53 Proteins with the Progression of Hepatocellular Carcinoma

Deranged expression of cell cycle modulators has been reported to contribute to the development and progression of hepatocellular carcinoma (HCC). However, their expression patterns remain poorly understood in hepatitis B virus (HBV)-related HCC, which constitutes about 65-70% of HCC in Korea. The aims of this study were to evaluate the expressions of G1-S modulators in HBV-related HCCs and dysplastic nodules (DNs), and to correlate with the histopathologic features of HCCs. Immunohistochemical expressions of cyclin D1, cyclin E, p53, p27, p21, p16, Rb, and PCNA proteins were investigated in 80 HCCs and 22 DNs. Cyclin D1 overexpression showed positive relationships with advanced tumor stage, poor differentiation, larger tumor size, microvascular invasion, intrahepatic meta-stasis, no tumor capsule formation, infiltrative growth, aberrant p53 expression, and high PCNA labeling index (LI) of HCC (p<0.05). Aberrant p53 expression showed positive relationship with poor differentiation of HCC (p<0.01). Expression of cyclin D1 or p53 was not observed in DNs. The p27 LI and p16 LI were lower in HCCs with intrahepatic metastasis (p<0.05). Cyclin D1 overexpression and aberrant p53 expression could be associated with the progression of HBV-related HCC, and might have a less crucial role in the DN-HCC sequence. In addition, elevated expression of p27 and p16 proteins might have inhibitory action to the intrahepatic metastasis of HBV-related HCC.