Análise comparativa de biomarcadores no câncer cervical invasivo e sua correlação com o tipo de HPV.

Submitted by Alessandra Portugal ([email protected]) on 2013-09-27T18:18:34Z No. of bitstreams: 1 SÉRGIO MENEZES AMARO FILHO.pdf: 3118907 bytes, checksum: 5ace372e7cf9ac4518a96c77052798ac (MD5)Made available in DSpace on 2013-09-27T18:18:34Z (GMT). No. of bitstreams: 1 SÉRGIO MENEZES AMARO FILHO.pdf: 3118907 bytes, checksum: 5ace372e7cf9ac4518a96c77052798ac (MD5) Previous issue date: 2012-03-30Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilO câncer cervical é o terceiro tipo de câncer mais comum entre mulheres no mundo. Dentre outros cofatores, a infecção pelo HPV de alto risco, tem sido bem documentada como fator necessário ao desenvolvimento desse tipo de câncer. A principal ação do HPV envolve a expressão massiva das oncoproteínas virais E6 e E7 que podem formar complexos específicos com proteínas supressoras de tumor, sendo capazes de alterar mecanismos do ciclo celular, modificando a expressão de proteínas celulares. Um dos principais avanços na medicina clínico patológica é o uso dessas proteínas como marcadores de forma a aumentar a acurácia do prognóstico e do próprio estadiamento do câncer cervical. Assim, a fim de reforçar a hipótese de que as proteínas associadas ao ciclo celular Ki-67, MCM-2, p53 e p16INK4a se encontram superexpressas no câncer cervical, foram analisadas em 87 amostras cervicais de pacientes com câncer invasivo (CCI) e 43 cérvix normais. Verificamos também se há uma expressão diferencial que pode ajudar a avaliação do estadiamento clínico da FIGO e quais tipos virais podem induzir a uma expressão diferencial dessas proteínas. Além disso, características sociodemográficas, comportamentais e clínicas das pacientes foram obtidas dos prontuários e analisadas. Para isso, a detecção de DNA de HPV foi realizada pela técnica da PCR e hibridização in situ. A expressão das proteínas foi observada por imunohistoquímica, seguida por quantificação manual e através do software ImagePro Plus. A análise estatística foi feita utilizando o software STATA/SE 10.1 aplicando os testes: Kruskall-Wallis, Student, Fisher e Qui-Quadrado. Nossos resultados mostraram forte associação (p<0,05) do CCI e dos estágios tumorais mais avançados (III e IV) com mulheres superiores a 55 anos, com mais de quatro gestações e sem escolaridade. A prevalência de DNA de HPV por PCR na população total foi de 73,4%. Nos grupos de CCI e controle foram, respectivamente, 94,3% e 29,3%. O tipo mais prevalente foi o HPV16 (70,8%), acompanhado pelo HPV33 (11,2%) e 35 (4,5%). Como esperado, foi observado aumento (p<0,05) na expressão de Ki-67, MCM-2, p53 e p16INK4a no CCI, quando comparados ao controle. A proteína p16INK4a com expressão difusa, citoplasmática e nuclear esteve associada ao câncer. Ki-67 apresentou forte expressão (>50%) conforme o agravamento da doença. Não foi observada associação entre a expressão de MCM-2, p53 e p16, e o estadiamento do tumor. Como conclusões, foram observadas maiores chances no desenvolvimento do CCI em mulheres com idades superiores a 55 anos, com mais de quatro gestações e sem escolaridades, estando esses fatores associados, também, à progressão tumoral. Apenas o marcador Ki-67 associouse ao estágio do CCI. Os tipos mais prevalentes encontrados, HPV16, 33, 35, 67 e 58, sugerem que novos estudos devam ser considerados para implementação de vacinação contra o HPV no Brasil.Cervical cancer is the thrid most common cancer among women worldwide. Beside others cofactors, infection with high risk HPV has been well documented as a necessary cause for cancer development. The main action involves the expression of massive HPV E6 and E7 viral oncoproteins that can form specific complexes with tumor suppressor proteins that are able of changing mechanisms of the cell cycle, modifying the expression of cellular proteins. One of the major advances in medicine clinical pathology is the use of these proteins as markers in order to improve the accuracy of prognosis and the cervical cancer stages. Thus, in order to reinforce strengthen the hypothesis that the proteins involved in cell cycle Ki-67, MCM-2, p53 and p16INK4a are over expressed in the uterine cervix of patients with cervical cancer, we analyzed 87 samples from patients with invasive cervical cancer (ICC) that were compared with 43 normal cervices (controls). Was verified also whether there is a differential expression that can help to assess the FIGO staging for ICC and which HPV viral types can induce a differential expression of these proteins. Moreover sociodemographic, behavioral and clinical characteristics of patients were obtained from medical records and analyzed. Therefore, the detection of HPV DNA was performed by PCR and in situ hybridization. By means of immunohistochemistry the expression of Ki-67, MCM2, p53 and p16 were analyzed. Statistical analysis was performed using STATA / SE 1.10 by applying the Kruskal-Wallis test, T-Student, chi-square and Fisher. Our results showed a strong correlation (p<0.05) of the CCI and the later stages of the cancer in women over 55 years, more than four pregnancies and no school education. The overall HPV DNA prevalence was 73.4%. On the ICC group and control group the prevalence was, respectively, 94.3% and 29.3%. The most prevalent HPV types were HPV16 (70.8%), HPV33 (11.2%) followed by HPV 35 (4.5%). Women with HPV16 were associated with advanced age (50.8 years) compared to women with other types (58.2 years). As expected, was observed an increase in Ki-67, MCM-2, p53 and p16 expression in CCI (p<0.05), compared to control. The expression of p16 protein with diffuse cytoplasmic and nuclear staining was associated with cancer. The Ki-67 showed a strong expression (> 50%) as the later stage of the disease. There was no association between the expression of MCM-2, p53 and p16 and tumor staging. In conclusion, we observed higher risks of ICC development in older ages, multiple pregancies and no school education. Only the Ki-67 marker was associated with the stage of the ICC. The most prevalent HPV types found, HPV 16, 33, 35, 67 and 58, suggest that new studies should be evaluated and considered on implementation of HPV vaccination in Brazil

HPV DNA methylation at the early promoter and E1/E2 integrity: A comparison between HPV16, HPV18 and HPV45 in cervical cancer

Objectives: To compare and describe type-specific characteristics of HPV16, HPV18 and HPV45 in cervical cancer with respect to 3′LCR methylation and disruption of E1/E2. Methods: The methylation level of 137 cervical cancer samples (70 with HPV16, 37 with HPV18, and 30 with HPV45) of Brazilian patients was analyzed by pyrosequencing. PCR amplifications were performed to characterize E1 and E2 disruption as an episomal surrogate. Results: The 3′LCR of HPV16 showed a higher methylation at all CpG sites (7%, 9%, 11%, 10% and 10%) than homologous HPV18 regions (4%, 5%. 6%, 9% and 5%) and HPV45 regions (7%, 7% and 5%). Presence of intact E1/E2 was associated with higher HPV16 and HPV18 methylation levels at all CpG sites (p < 0.05). Disruption of E1/E2 was more frequently found in HPV45 (97%) and HPV18 (84%) than in HPV16 DNA (30%). HPV16 disruption was more frequently found in E1 (48%) unlike HPV18, where it was found in E2 (61%). Concomitant disruption of E1/E2 was most frequent in HPV45 (72%). Conclusions: The findings showed a higher methylation associated with intact E1/E2 for HPV16 and HPV18. The closely phylogenetic related HPV18 and HPV45 share a similar methylation level and the frequency of viral genome disruption. Keywords: Human papillomavirus, Invasive cervical cancer, Methylation, Pyrosequencing, HPV genome, Viral genome integratio

A comparative analysis of clinical and molecular factors with the stage of cervical cancer in a brazilian cohort

Submitted by Luis Guilherme Macena ([email protected]) on 2013-07-31T16:33:15Z No. of bitstreams: 1 A Comparative Analysis of Clinical and Molecular Factors.pdf: 1117978 bytes, checksum: 9363a0174c2fd7de506f55cbf0020692 (MD5)Made available in DSpace on 2013-07-31T16:33:15Z (GMT). No. of bitstreams: 1 A Comparative Analysis of Clinical and Molecular Factors.pdf: 1117978 bytes, checksum: 9363a0174c2fd7de506f55cbf0020692 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório Interdisciplinar de Pesquisa Médica. Rio de Janeiro, RJ, Brasil.Johns Hopkins Bloomberg School of Public Health. Department of Epidemiology Infectious Diseases. Baltimore, Maryland, USA.Ohio State University. Comprehensive Cancer Center. Columbus, Ohio, USA.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Universidade de São Paulo. Instituto de Medicina Tropical Laboratório de Virologia. São Paulo, SP, Brasil.Hospital Alemão Oswaldo Cruz. São Paulo, SP, Brasil.Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Niterói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório Interdisciplinar de Pesquisa Médica. Rio de Janeiro, RJ, Brasil.Cell cycle protein expression plays an important role in the pathophysiology of cervical cancer. However, few studies have attempted to correlate the use of these biomarkers with the clinical progression of the tumor. Objectives:1) To analyze the expression of Ki-67, p53 and p16 INK4a in cervical cancer, 2) to correlate the relative expression of these proteins as well as clinical parameters with the stage of disease, and 3) to determine the HPV DNA prevalence and subtype distribution. Methods:Tissue Micro-Arrays (TMA) from patients with invasive cervical cancer (ICC) and controls were analyzed. HPV DNA detection was done by PCR and in situ hybridization. Ki-67, p53 and p16 INK4a were analyzed by immunohistochemistry; clinical data was derived from the chart review. Results:Advanced tumor stage (III and IV) was strongly associated (p,0.005) with advanced age (.55 years old), with more than four pregnancies and with the lack of formal education. HPV DNA was found in 94.3% of cases with the most prevalent types being HPV16 (67.5%), followed by HPV33 (12.0%) and HPV35 (3.6%). High expression of Ki-67 and p16 was more common in the advanced FIGO stages (p = 0.023). Women with HPV16 tended to be younger (50.9 years; SE 1.9) compared to women with other types (59.9 years; SE 2.8). Conclusion:We found that Ki-67 and p16 expression were independently associated with the tumor stage. We also noted that about 1/3 of the cervical cancers in this Brazilian cohort were not associated with HPV types directly targeted by the current HPV vaccines