Alterations in the expression and activity of extracellular matrix components in HPV-associated infections and diseases

Infection with human papillomaviruses is associated with a series of benign and malignant hyperproliferative diseases that impose a heavy burden on human populations. A subgroup of mucosal human papillomavirus types are associated with the majority of cervical cancers and a relevant fraction of vulvar, vaginal, anal, penile and head and neck carcinomas. Human papillomaviruses mediate cell transformation by the expression of two pleiotropic oncoproteins that alter major cellular regulatory pathways. However, these viruses are not complete carcinogens, and further alterations within the infected cells and in their microenvironment are necessary for tumor establishment and progression. Alterations in components of the extracellular matrix for instance, matrix metalloproteinases and some of their regulators such as tissue inhibitors of metalloproteinases, have been consistently reported in human papillomaviruses-associated diseases. Matrix metalloproteinases function by remodeling the extracellular matrix and alterations in their expression levels and/or activity are associated with pathological processes and clinical variables including local tumor invasion, metastasis, tumor relapse and overall patient prognosis and survival. In this review we present a summarized discussion on the current data concerning the impact of human papillomavirus infection on the activity and expression of extracellular matrix components. We further comment on the possibility of targeting extracellular matrix molecules in experimental treatment protocols.

Oxidative stress: therapeutic approaches for cervical cancer treatment

OBJECTIVES: Oxidative stress results from an imbalance between the generation and elimination of oxidant species. This condition may result in DNA, RNA and protein damage, leading to the accumulation of genetic alterations that can favor malignant transformation. Persistent infection with high-risk human papillomavirus types is associated with inflammatory responses and reactive oxygen species production. In this context, oxidative stress, chronic inflammation and high-risk human papillomavirus can act in a synergistic manner. To counteract the harmful effects of oxidant species, protective molecules, known as antioxidant defenses, are produced by cells to maintain redox homeostasis. In recent years, the use of natural antioxidants as therapeutic strategies for cancer treatment has attracted the attention of the scientific community. This review discusses specific molecules and mechanisms that can act against or together with oxidative stress, presenting alternatives for cervical cancer prevention and treatment.

Detección de virus papiloma humano (HPV) a partir de muestras celulares de cuello uterino en base líquida: Correlación con la inmunorreactividad de la proteína p16INK4a / Detection of human papilloma virus (HPV) in liquid-based cervical samples: Correlation with protein p16INK4a expression

La citología del cuello uterino en base líquida mejora la calidad de la muestra y el material residual podría ser utilizado para realizar pruebas complementarias, como la detección del virus papiloma humano (HPV) y estudio inmunocitoquímico de biomarcadores. El propósito de este estudio fue correlacionar la presencia de HPV y la inmunoexpresión de p16INK4a en las muestras citológicas en base líquida para examinar la utilidad de estas nuevas herramientas en la detección de cáncer de cuello uterino. Las pacientes incluidas (n=67) presentaban una citología anormal o patología cervical previa. La detección y genotipificación de HPV se realizó con PCR-SPF10/LiPA (INNOLiPA Extra Amp) y para la inmunodetección de p16INK4a se utilizó el anticuerpo clon E6H4. La citología convencional proporcionó los mismos hallazgos citológicos que la citología en base líquida. La prevalencia general del HPV fue de 43,3% (29/67). El HPV16 fue el tipo viral mas frecuente (31,03%) y el 48,3% de los casos presentó infección múltiple. En el 35,8% de las muestras cervicales se detectó inmunoexpresión de la p16INK4a y ésta fue significativamente (p<0,020) asociada a la presencia de HPV. Estos resultados apoyan la evidencia que la implementación de nuevas tecnologías en la rutina diaria del laboratorio contribuye significativamente en la detección precoz del cáncer de cuello uterino y en el aporte de datos importantes para facilitar en el manejo clínico adecuado de la paciente. La detección de HPV combinada con la p16INK4a podría ser utilizado en la evaluación de pacientes con mayor riesgo a desarrollar lesiones cervicales significativas.

The liquid-based cervical cytology improves the quality of the sample and the residual sample could be used efficiently to carry out complementary tests, such as the detection of HPV DNA and the immunocytochemical biomarkers study. The purpose of this study was to correlate the presence of HPV and immunoexpression of p16INK4a in liquid-based cervical samples to examine the utility of these new tools in the detection of cervical cancer. The included patients (n=67) presented an abnormal cytology or previous cervical pathology. The HPV detection and genotyping were carried out with PCR-SPF10/LiPA (INNOLiPA Extra Amp) and for p16INK4a immunodetection was used antibody clone E6H4. The conventional cytology provided the same cytologic interpretations that those of liquid-based cytology. The overall HPV prevalence was 43.3% (29/67). HPV16 was the most frequent viral type (31.03%) and 48.3% of the cases were infected with multiple HPV types. p16INK4a immunoexpression was observed in 35.8% of liquid-based cytological samples and this was significantly (p < 0.020) associated to the HPV presence. These results support the evidence that the implementation of new technologies in the daily routine of the laboratory, contribute significantly in the early detection of cervical cancer and provide important data to help in the patient’s efficient management. The combined use of HPV detection and p16INK4a expression could be used for evaluation of patients with more risk to develop significant cervical lesions.

Existe alteração no mecanismo de adesão celular mediado pela E-caderina nas neoplasias cervicais de pacientes soropositivas para o HIV? / Is there any change in the cell adhesion method mediated by e-cadherin in cervical neoplasia of HIV-infected patients?

OBJETIVOS: avaliar a expressão da E-caderina em lesões do colo uterino em pacientes portadoras da infecção pelo vírus HIV. MÉTODOS: foi realizado um estudo com 77 pacientes apresentando o HPV cervical, sendo 40 soropositivas e 37 soronegativas para o HIV, todas submetidas à colposcopia e biópsia de colo uterino. O material obtido foi encaminhado para histopatologia e imunoistoquímica. Foram realizados cortes e montagem em lâminas silanizadas, e o observador foi blindado para a sorologia da paciente. Foram utilizados os anticorpos E-caderina, marca DAKO, clone NHC-38, com diluição de 1:400, e o sistema de polímeros Novolink (Novocastra). A expressão de E-caderina foi avaliada na membrana da célula epitelial, através da extensão da área corada. Utilizou-se o teste do χ2 com correção de Yates ou o teste de Fisher, para comparação de proporções na análise univariada. Foram incluídas no modelo de regressão logística todas as variáveis com valor p<0,25, chamado de modelo inicial. Foi utilizado o pacote estatístico SPSS e adotado o nível de significância estatística de 5 por cento. RESULTADOS: a expressão da E-caderina foi identificada em até 1/3 interno do epitélio em 59,3 por cento dos casos e em até 2/3 do epitélio em 11,1 por cento dos casos, mas em 29,6 por cento dos casos a expressão foi identificada em toda a espessura do epitélio entre as pacientes soronegativas para o HIV. Por outro lado, nas pacientes soropositivas para o HIV, verificou-se 45,9 por cento com expressão em até 1/3 do epitélio, 13,5 por cento com expressão até 2/3 do epitélio e 40,5 por cento em toda a espessura do epitélio. A expressão da E-caderina não foi diferente entre os dois grupos (p=0,5). A análise multivariada, contudo, identificou associação significativa entre as lesões cervicais de alto grau e a expressão da E-caderina em 2/3 e 3/3 do epitélio (p<0,001; χ2=36,9). CONCLUSÕES: a expressão da E-caderina na membrana das células epiteliais não está associada à infeção pelo vírus da imunodeficiência humana, e sim ao grau da lesão intraepitelial cervical.

PURPOSE: to evaluate the expression of E-cadherin in cervical lesions of patients suffering from HIV infection. METHODS: we conducted a study with 77 patients with cervical HPV infection, 40 of them were HIV seropositive and 37 HIV seronegative who underwent colposcopy and a biopsy of the cervix. The material obtained by biopsy of the cervix was sent for histopathologic and immunohistochemical study. Sections were obtained and mounted on silanized slides and examined by an observer who was blind to patient serology. E-cadherin antibody, clone NHC-38 diluted 1:400 (DAKO) and the Novolink polymer system (Novocastra) were used. The expression of E-cadherin was determined on the epithelial cell membrane based on the extent of the stained area. The χ2 test with Yates correction or the Fisher's Exact test was used for comparison of the proportion in univariate analysis. All the variables with p<0.25 were included in the logistic regression model, called initial model. The analyses were carried out using the SPSS software, with the level of significance set at 5 percent. RESULTS: the expression of E-cadherin was observed in up to the internal 1/3 of the epithelium in 59.3 percent of cases and in up to 2/3 of the epithelium in 11.1 percent of cases, but in 29.6 percent of cases the expression was identified throughout the thickness of the epithelium in HIV-seronegative patients. In contrast, in HIV-seropositive patients, 45.9 percent showed expression up to 1/3 of the epithelium, 13.5 percent showed expression in up to 2/3 of the epithelium, and 40.5 percent showed expression throughout the thickness of the epithelium. E-cadherin expression did not differ between groups (p=0.5). However, the multivariate analysis identified a significant association between high-grade cervical injury and E-cadherin expression in 2/3 and 3/3 of the epithelium (p=0.001; χ2=36.9). CONCLUSIONS: the expression of E-cadherin in the epithelial cell membrane is not associated with infection by the human immunodeficiency virus, but with the degree of intraepithelial cervical injury.

Carcinoma de pênis: panorama da doença no Estado da Bahia. Considerações epidemiológicas e histopatológicas / Carcinoma of the penis: an overview of the disease in the state of Bahia. Epidemiological considerations and histopathological

O câncer de pênis é um problema de saúde pública principalmente em países em desenvolvimento. No Brasil, a incidência é alta e as regiões Nordeste e Sudeste são as mais afetadas, concentrando, respectivamente, 41,9% e 40,4% dos casos, segundo dados da Sociedade Brasileira de Urologia. Com o objetivo de conhecer melhor as características da doença no Estado, procedemos a revisão de prontuários e lâminas histológicas dos pacientes com a doença, atendidos do Hospital Aristides Maltez, Bahia, entre janeiro de 1997 a dezembro de 2007. Foram estudados 314 pacientes, a média de idade foi de 57 anos, 45% dos pacientes eram analfabetos e pacientes pardos representaram 83,8% da amostra. Amputação foi o procedimento mais comum, realizado em 288 casos (74,1%), linfadenectomias foram realizadas em 77 pacientes. Alterações histológicas sugestivas de infecção por HPV foram observadas em 239 (75,9%) pacientes. Segundo a classificação da OMS de 2004, o carcinoma usual foi o mais freqüente, com 241 (76,8%) casos e os subtipos representaram 23,2% da amostra. Dentre os subtipos, o misto e o Warty foram os mais observados, 29 (9,2%) e 26 (8,2%) e sarcomatóides e verrucosos foram os menos freqüentes, 1 (0,3%) e 2 (0,6%) dos casos, respectivamente. Observamos características clínicas semelhantes: baixo nível econômico e social, baixíssimo nível de instrução, predominância de pardos e negros, dificuldade de acesso aos serviços de saúde, tempo arrastado de sintomatologia, média de idade de 57 anos, além de altas taxas de infecção por HPV. Aspectos clínico-patológicos de mais de 300 pacientes foram apresentados e revistos segundo nova classificação da OMS de 2004. Nossa série é uma das primeiras a rever os casos segundo esta nova classificação, importante para prever a evolução destes tumores e auxiliar a clínicos e cirurgiões a estabelecer a melhor estratégia no tratamento. Conhecer o perfil da doença no Estado possibilita a criação de medidas voltadas à prevenção, diagnóstico e tratamento precoce para diminuir a incidência e morbidade desta triste realidade da doença em nosso país. Assim como permite a longo prazo a continuidade de um trabalho de investigação que possa responder a questões ainda não entendidas sobre a doença.

Inmunohistoquímica de la proteína p16INK4a en biopsias y extendidos cervicovaginales y su relación con HPV por PCR / Immunohistochemistry of p16INK4a in biopsies and cervicovaginal smears, and its correlation with HPV detected by PCR

Estudios recientes sugieren que la sobreexpresión de p16, determinada por inmunohistoquímica, sería un marcador específico de células escamosas displásicas y neoplásicas con alta asociación con HPV de alto riesgo. Nuestro objetivo fue correlacionar los hallazgos cito/histológicos con la expresión de p16 y el subtipo de HPV por PCR. Seleccionamos 95 biopsias de cuello uterino y 4 legrados endocervicales de 99 individuos, y 30 extendidos cervicovaginales de otros 30 individuos, que se dividieron según el diagnóstico morfológico. Inmunomarcamos cortes del material incluido en parafina y los extendidos con el kit CINtecT p16INK4a (DAKO). Evaluamos HPV por PCR utilizando 25/99 biopsias con lesión intraepitelial escamosa de bajo grado. Observamos marcación positiva para p16 en 1/35 biopsias (2.9%) y 1/11 extendidos (9%) en los grupos sin HPV ni displasia; 16/25 biopsias (64%) y 6/10 extendidos (60%) en aquellos con lesión de bajo grado y 38/39 biopsias (97.4%) y 8/9 extendidos (89%) en los grupos con lesión de alto grado y carcinoma escamoso. Todas las muestras con HPV-6/11 fueron negativas o positivas focales para p16, en tanto que aquellas con HPV-18 u otros subtipos fueron mayoritariamente positivas de tipo difuso. Concluimos que la expresión de p16 presenta alta correlación con el diagnóstico cito/histológico y alta asociación entre la marcación difusa y la presencia de HPV de alto riesgo, aportando mayor objetividad en casos dudosos y ayudando a seleccionar grupos de individuos con riesgo de progresión de enfermedad, con un costo aceptable para estudiar grandes grupos.

Recent studies suggest that p16 overexpression determined by immunohistochemistry would be a specific marker for neoplastic and dysplastic squamous cells associated with high-risk HPV. The purpose of this study was to assess the correlation between cyto-histological findings, p16 expression and HPV subtype. A total of 99 biopsies were selected, 4 endocervical curettages and 95 uterine cervix biopsies, as well as 30 cervicovaginal smears from other 30 patients. The samples were divided according to the morphological diagnosis. Paraffin-embedded sections and cervicovaginal smears were immunostained using the CINtecT p16INK4a Cytology Kit (DAKO). HPV was analyzed by PCR in 25 of the 99 biopsies with low-grade squamous intraepithelial lesion. Among those patients with neither HPV nor dysplasia, 1 of 35 (2.9%) biopsies and 1 of 11 (9%) smears were positive for p16. Sixteen of 25 (64%) biopsies and 6 of 10 (60%) smears of the low-grade lesion cases, and 38 of 39 (97.4%) biopsies and 8 of 9 (89%) smears of the high-grade lesion and squamous carcinoma were positive for p16. All cases of HPV-6/11 were negative or focally positive for p16. Most cases of HPV-18 or other subtypes were diffusely positive. Our results indicate that p16 expression is highly correlated with cyto-histological diagnosis, and is associated with diffuse staining and high-risk HPV. This technique provides greater objectivity in doubtful cases, and helps select patients at risk of disease progression at an acceptable cost when used in large populations.

Análisis de expresión global del cáncer cérvico uterino: rutas metabólicas y genes alterados / Global expression analysis in uterine cervical cancer: Metabolic pathways and altered genes

High risk human papillomavirus (HPV) infection is considered to be the most important etiological factor of Cervical Uterine Cancer. In order to determine the global expression pattern and to identify possible molecular markers of cervical cancer, cDNA arrays with probe sets complementary to 8,000 human genes were used to examine the expression profiles among 5 cell lines derived from human cervical cancer, three HPV16(+) tumor samples and three normal cervical tissues HPV(-). The levels of expression of different cellular processes were identified. Hierarchical clustering was performed and the gene expression using RT-PCR was confirmed. Two genes were found to be consistently overexpressed in invasive cervical cancer biopsies; one of them, IL-6 was previously reported to be overexpressed in cervical cancer and one novel gene, MMP10, previously not known to be related to cervical cancer. Hierarchical clustering of the expression data revealed that samples with common HPV type infection grouped together, maybe this could mean that differences between HPV types could be indirectly determined by expression profiles.

La infección por virus de papiloma de alto riesgo (VPH) es considerada como el factor etiológico más importante del cáncer cérvico uterino (CaCU). Con el fin de determinar el patrón de expresión global e identificar algunos posibles genes marcadores del CaCU, se utilizaron microhileras de DNA que contenían 8,000 secuencias que codificaban para transcritos diferentes, para estudiar los perfiles de expresión de cinco líneas celulares derivadas de CaCU, tres muestras tumorales conteniendo VPH 16 y tres muestras normales negativas para la presencia de VPH. Se identificaron los niveles de expresión de genes relacionados con diferentes rutas metabólicas. Se llevó a cabo el análisis de agrupamiento jerárquico y posteriormente se confirmó la sobrexpresión de dos genes mediante RT-PCR. Estos dos genes se encontraron sobrexpresados en biopsias tumorales cervicales. Uno de ellos, el gen de IL6, que ha sido previamente reportado en relación con CaCU, así como el gen de la matriz-metaloproteasa 10 (MMP10) por primera vez relacionado con esta neoplasia. El análisis de agrupamiento jerárquico, además, reveló que las muestras que contienen el mismo tipo viral están asociadas, sugiriendo posibles diferencias en expresión entre tipos virales.

Mechanisms of cell transformation induced by polyomavirus

Polyomavirus is a DNA tumor virus that induces a variety of tumors in mice. Its genome encodes three proteins, namely large T (LT), middle T (MT), and small T (ST) antigens, that have been implicated in cell transformation and tumorigenesis. LT is associated with cell immortalization, whereas MT plays an essential role in cell transformation by binding to and activating several cytoplasmic proteins that participate in growth factor-induced mitogenic signal transduction to the nucleus. The use of different MT mutants has led to the identification of MT-binding proteins as well as analysis of their importance during cell transformation. Studying the molecular mechanisms of cell transformation by MT has contributed to a better understanding of cell cycle regulation and growth control