No description available.

No description available.

No description available.

Head and neck cancer (HNC) is one of the top ten cancers in the world, and is caused by tobacco use, alcohol consumption and Human Papillomavirus (HPV). HPV associated HNC patients have improved survival rates compared to non -HPV associated HNC patients. This improved survival is due to HPV- positive tumors favorable response to chemotherapy and radiation. The literature has shown that there is a racial disparity in survival rates between Caucasians and African Americans, with African Americans having poorer survival rates. The aim of this study is to determine if the racial disparity among HNC patients is due to a difference in HPV prevalence between races. HPV prevalence in HNC was assessed by a meta-analysis of published articles (30/247) that reported race specific HPV prevalence. We also conducted a pooled analysis in which authors that assessed HPV in HNC were invited to submit their datasets. Meta-pooled prevalence estimates revealed that 20% of African American HNC patients had HPV-positive tumors, compared to 44% in Caucasians. However for both African American HNC patients and Caucasian HNC patients there was low to moderate heterogeneity between the studies (Q-test p-value = p < 0.001, I2 = 18.87%, and p= 0.008. I2 =65.47% respectively). The prevalence of HPV in African Americans was 60% and in Caucasians it was 39%. African Americans had a risk of oropharyngeal cancer that was no different from Caucasians (OR: 1.38, 95% CI: 0.53-3.62) but had an increased risk of death from oropharyngeal cancer (HR: 2.39, 95% CI 1.03-5.55) compared to Caucasians. The results of the pooled analysis does not support the concept that African Americans HNC patients have a lower prevalence of HPV, but substantiates the notion that African Americans have worse survival than Caucasians. However, these are preliminary results as the pooled analysis is still being conducted, the inclusion of more datasets in the analysis could alter these preliminary findings. / Public Health

Human papillomaviruses (HPV) have been implicated as etiologic agents in the genesis of cervical carcinoma and certain other benign lesions of the cervix. Clinical and epidemiological data, and the demonstration of HPV 16 viral DNA sequences in cervical cancer biopsies lend support to the etiologic association of HPV type 16 and cervical carcinoma. Interpretation of the association between HPV 16 and cervical cancer is limited by methods of detection. Different methods of detection of viral DNA sequences have been used based on DNA-DNA hybridization. Recently, a method based upon the in vitro enzymatic amplification of specific viral DNA sequences or polymerase chain reaction (PCR) has been used. The purpose of this study was to compare PCR with DNA-DNA hybridization methods in clinical specimens obtained from invasive cervical cancer. The in vitro enzymatic amplification or PCR was carried out on three specific regions of HPV 16. E6, E7 and L1 regions of HPV 16 were chosen as the target sequences of amplification and primers were synthesized specific to these regions. PCR was performed on 163 cervical cancer specimens using primers specific for E6 and E7 regions of HPV 16. 112 of these specimens were also analyzed using L1 primers of HPV 16. Estimates of sensitivity and specificity of the different methods to see if PCR is a better, more sensitive method compared to the other methods were computed. The results suggest that although percent positivity by PCR method increases significantly, thereby improving sensitivity of detection, the specificity suffers compared to the other methods. However the advantages of using PCR as a diagnostic tool are attractive, as it requires only picogram quantities of DNA, is rapid and easy to perform, and is amenable to automation. / Thesis / Master of Science (MS)

O câncer cervical é o segundo mais comum em mulheres em países em desenvolvimento, sendo causado por infecção persistente por Papilomavírus Humano (HPV). Quando esta persistência ocorre, entre outros fatores, está relacionada a mecanismos de evasão do sistema imune apresentados pelo vírus. A frequência de macrófagos aumenta com a progressão da lesão cervical e há aumento de células mielóides no baço de camundongos com tumor. Este trabalho tem como objetivo observar os efeitos sistêmicos de tumores associados ao HPV sobre a proliferação e recrutamento de células do sistema imune e identificar fatores que tenham papel nesses mecanismos. Utilizando modelos de tumor in vivo, observou-se que tumores associados ao HPV recrutam mais células para o tumor e induzem maior proliferação celular. Também avaliamos o perfil de expressão de citocinas nas linhagens tumorais e o perfil geral de expressão de proteínas através de eletroforese 2D. Com isto, demonstramos que linhagens tumorais positivas para HPV apresentam maior expressão de IL-6, IL-8, CXCL1, sICAM e Serpina E1. / Cervical cancer is the second most common type of cancer in women in developing countries. Its main etiologic factor is persistent infection with high risk human papillomavirus (HPV). This persistence occurs only in some cases and, among other factors, is related to mechanisms of immune evasion displayed by the virus. There is an increase in the frequency of macrophages proportional to cervical intraepithelial lesion grade and an increase of myeloid cells in the spleen of tumor bearing mice. This work aims to observe the systemic effects of HPV associated tumors on the proliferation and recruitment of immune cells, and identify factors that have a role in these mechanisms. Using in vivo tumor models, we found that HPV positive tumors recruit a higher percentage of cells and induce cellular proliferation. We also studied cytokine expression profiles of tumor cell lines, and performed proteomic assay with tumor cells transduced with HPV oncogenes. Our data shows that HPV associated tumor cell lines display higher expression of IL-6, IL-8, CXCL1, sICAM and Serpin E1.

O HPV é transmitido principalmente pelo contato sexual e as infecções causadas por tipos virais oncogênicos estão etiologicamente associadas com o desenvolvimento de câncer de colo de útero, vulva e ânus nas mulheres, câncer de pênis e ânus nos homens, e câncer de cabeça e pescoço em ambos os sexos. Além disso, as verrugas genitais e a rara, mas séria, papilomatose respiratória estão etiologicamente associadas aos HPVs de baixo risco 6 e 11. Ademais, os HPV-16 e 6 estão entre os tipos mais frequentemente detectados em homens, independentemente da origem da amostra estudada, ressaltando a importância epidemiológica do HPV-6. Até o momento, estudos de associação entre variantes moleculares de HPV e o desenvolvimento das doenças associadas foram realizados para os HPVs de alto-risco oncogênico, como os HPV-16 e -18. Em relação à prevalência dos HPVs de baixorisco oncogênico e as implicações da heterogeneidade viral, os dados existentes até o momento são escassos. Pelo exposto, este projeto tem por objetivo: (1) Determinar a prevalência das diferentes variantes moleculares de HPV-6 em esfregaços genitais e lesões genitais externas (LGE), especificamente em verrugas genitais (VGs), entre os participantes do estudo prospectivo multinacional da Infecção por HPV em homens (estudo HIM); (2) Verificar a associação entre a infecção por diferentes variantes moleculares de HPV-6 e o risco de desenvolvimento de LGE nos participantes do estudo HIM. Para atingir os objetivos propostos foram utilizados esfregaços genitais e amostras de verruga genital dos participantes HPV-6 positivos do estudo HIM. Nestas amostras, as variantes de HPV-6 foram caracterizadas através da amplificação por PCR e sequenciamento de um fragmento do gene L2. Isto permitiu classificar as amostras em todas as linhagens (A, B) e sub-linhagens (B1, B2, B3, B4, B5) de HPV-6 descritas. Neste estudo, as variantes da sub-linhagem B3 foram as mais prevalentes. A distribuição das variantes de HPV-6 diferiu entre os países e entre casos e controles. A prevalência das variantes B1 de HPV-6 estava aumentada em VGs e esfregaços genitais de casos em comparação aos controles. Diferenças entre a detecção de variantes B1 e B3 nas VG e no esfregaço genital precedente à lesão foram observadas. Foi encontrada uma associação significativa entre a detecção de variantes da sub-linhagem B1 de HPV-6 e o desenvolvimento de VGs. Em conclusão, variantes B1 de HPV-6 são mais prevalentes em esfregaços genitais normais que precedem o desenvolvimento de VGs. Ademais as variantes B1 conferem risco aumentado para o desenvolvimento de VGs. Estudos futuros são necessários para compreender o possível envolvimento aumentado de variantes B1 de HPV-6 na progressão para lesões clinicamente relevantes / HPV is primarily transmitted through sexual contact and infections caused by oncogenic viral types are etiologically associated with the development of cervical, vulvar and anal cancer, in women, penile and anal cancer in men, and head and neck cancer in both sexes. Moreover, genital warts and the rare, but serious, respiratory papillomatosis are etiologically associated with low-risk HPV types -6 and -11. Additionally, data obtained from different studies show that HPV types -16 and -6 are among the most frequently detected types in men, independently of the origin of the samples studied, underscoring the epidemiological relevance of HPV-6. To date, studies focusing on the association between HPV molecular variants and disease onset have been conducted on high-risk types such as -16 and -18. Regarding the prevalence of low-risk HPVs and the implications of their viral heterogeneity, date is still scarce. In light of these facts, the objectives of this project are to: (1) Determine the prevalence of HPV-6 molecular variants in genital swabs and external genital lesions (EGL), specifically genital warts (GW), among participants of the prospective and multinational HPV infection in men study (HIM study); (2) To verify the association between HPV-6 molecular variants infection and the risk of developing EGL among HIM study participants. To achieve the proposed objectives, genital swabs and genital wart samples from HPV-6 positive HIM study participants were used. In these samples, HPV-6 variants were characterized by PCR amplification followed by sequencing of an L2 gene fragment. This allowed for the classification of the samples into all described HPV-6 lineages (A, B) and sub-lineages (B1, B2, B3, B4, B5). In this study, variants belonging to B3 sub-lineage were the most prevalent. HPV-6 variants distribution differed between countries and between cases and controls. HPV-6 B1 variants prevalence was increased in GWs and genital swabs of cases compared to controls. Differences among B1 and B3 variants detection in GW and the preceding genital swab were observed. A significant association of HPV-6 B1 variants detection with GW development was found. In conclusion, HPV-6 B1 variants are more prevalent in normal genital swabs that precede GW development. Additionally, B1 variants confer an increased risk for GW development. Further research is needed to understand the possible increased involvement of B1 variants in the progression to clinically relevant lesions

O HPV (Papilomavírus Humano) causa verrugas anogenitais e alguns tipos de câncer, como o câncer de colo do útero. Seu capsídeo é composto pelas proteínas L1 e L2. A L1 se autoestrutura em VLPs, utilizadas nas atuais vacinas comerciais. Para a geração de vacinas com maior espectro de proteção, a L2 é promissora, pois gera proteção cruzada. Para caracterizar VLPs de L1L2 do HPV16, células HEK293T cotransfectadas tiveram a expressão proteica analisada por citometria de fluxo, Western blotting, microscopia confocal a laser e eletrônica de transmissão. As proteínas L1 (60kDa) e L2 (100kDa) estavam presentes no núcleo e no citoplasma celular, formando VLPs de L1L2 de conformação heterogênea, cuja máxima expressão ocorre 12h após a transfecção. As VLPs extraídas estavam em diferentes estágios de estruturação. Foi possível estabelecer um sistema eficaz de produção heteróloga das proteínas de VLPs de L1L2, que poderão ser utilizadas em testes pré-clínicos, na pesquisa básica e contribuir no desenvolvimento de uma vacina profilática de amplo espectro de ação contra o HPV. / HPV (Human Papillomavirus) is the causative agent of anogenital warts and several types of cancer, as cervical cancer. The HPV capsid is composed of L1 and L2 proteins. L1 can self-assemble into VLPs (virus-like particles), the basis for HPV commercially available vaccines. To generate broad-spectrum vaccines L2 shows the greatest promise, due to cross-protection. To characterize VLPs composed of HPV16 L1 and L2 proteins, cotransfected HEK293T cells were analyzed by flow cytometry, confocal laser scanning microscopy, transmission electron microscopy and Western blotting. Proteins L1 (60kDa) and L2 (100kDa) were present in cell nucleus and cytoplasm, forming heterologous L1L2 VLPs with highest expression at 12h post-transfection. Extracted VLPs were at different maturation stages. It was possible to establish an efficient system of heterologous L1, L2 and L1L2 VLPs production. After some adjustments in protocols, these particles could be used in preclinical tests, HPV basic research and also in the development of an HPV broad-spectrum vaccine.

Tam On Yi Ann. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 138-152). / Abstracts in English and Chinese. / ABSTRACT --- p.I / ACKNOWLEDGMENTS --- p.VI / ABBREVIATIONS --- p.VIII / LIST OF FIGURES --- p.X / LIST OF TABLES --- p.XI / CONTENTS --- p.XII / Chapter Chapter One: --- Introduction --- p.1 / Chapter 1.1 --- History of human papillomavirus --- p.2 / Chapter 1.2 --- Biology of human papillomavirus --- p.4 / Chapter 1.2.1 --- Classification --- p.4 / Chapter 1.2.2 --- Genome structure --- p.5 / Chapter 1.2.3 --- Properties of gene products --- p.6 / Chapter 1.2.3.1 --- El gene --- p.6 / Chapter 1.2.3.2 --- E2 gene --- p.7 / Chapter 1.2.3.3 --- E4 gene --- p.7 / Chapter 1.2.3.4 --- E5 gene --- p.7 / Chapter 1.2.3.5 --- E6 gene --- p.7 / Chapter 1.2.3.6 --- E7 gene --- p.8 / Chapter 1.2.3.7 --- LI and L2 genes --- p.9 / Chapter 1.2.4 --- Latent and lytic life cycle --- p.9 / Chapter 1.2.5 --- Host specificity --- p.10 / Chapter 1.2.6 --- Site of infection --- p.11 / Chapter 1.2.7 --- Clinical manifestations --- p.11 / Chapter 1.2.8 --- Mode of infection --- p.12 / Chapter 1.2.9 --- Detection method --- p.13 / Chapter 1.2.9.1 --- DNA hybridization --- p.13 / Chapter 1.2.9.2 --- DNA amplification methods --- p.15 / Chapter 1.2.9.3 --- Hybrid capture assay --- p.16 / Chapter 1.2.9.4 --- Other DNA detection methods --- p.17 / Chapter 1.2.9.5 --- Serology --- p.18 / Chapter 1.3 --- Biology of cervical intraepithelial neoplasia and cervical cancer --- p.19 / Chapter 1.3.1 --- Grading of severity of cervical neoplasia --- p.20 / Chapter 1.3.2 --- Treatment of cervical intraepithelial lesions --- p.22 / Chapter 1.3.3 --- Prognosis after treatment --- p.22 / Chapter 1.4 --- Epidemiology of cervical cancer --- p.23 / Chapter 1.4.1 --- Global burden of disease --- p.23 / Chapter 1.4.2 --- Local burden of disease --- p.23 / Chapter 1.4.2.1 --- Incidence --- p.23 / Chapter 1.4.2.2 --- Mortality --- p.24 / Chapter 1.4.2.3 --- Age distribution --- p.24 / Chapter 1.4.2.4 --- Trends of incidence and mortality --- p.25 / Chapter 1.4.2.5 --- Morbidity --- p.25 / Chapter 1.4.2.6 --- International comparison --- p.25 / Chapter 1.5 --- Aetiology and risk factors --- p.26 / Chapter 1.5.1 --- Human papillomavirus infection --- p.26 / Chapter 1.5.2 --- Number of sexual partners --- p.26 / Chapter 1.5.3 --- Age of first sexual intercourse --- p.27 / Chapter 1.5.4 --- Presence of other sexually-transmitted diseases --- p.28 / Chapter 1.5.5 --- Cigarette smoking --- p.29 / Chapter 1.5.6 --- Diet --- p.30 / Chapter 1.5.7 --- Oral contraceptives --- p.30 / Chapter 1.5.8 --- Parity --- p.31 / Chapter 1.5.9 --- Age --- p.32 / Chapter 1.5.10 --- Socio-economic status --- p.32 / Chapter 1.6 --- Malignant transformation of human papillomavirus infection --- p.33 / Chapter 1.7 --- Primary prevention of cervical cancer - vaccine for human papillomavirus --- p.38 / Chapter 1.7.1 --- Classification of vaccine for human papillomavirus --- p.38 / Chapter 1.7.2 --- Human papillomavirus vaccination combined with human papillomavirus screening --- p.39 / Chapter 1.8 --- Secondary prevention of cervical cancer --- p.40 / Chapter 1.8.1 --- Cytology screening --- p.40 / Chapter 1.8.2 --- Detection of human papillomavirus --- p.41 / Chapter 1.9 --- Human papillomavirus and cervical cancer --- p.43 / Chapter 1.9.1 --- Risk association between cervical cancer and human papillomavirus infection --- p.43 / Chapter 1.9.2 --- World-wide prevalence of human papillomavirus types in cervical cancer --- p.43 / Chapter 1.9.3 --- Human papillomavirus prevalence in China and Hong Kong --- p.44 / Chapter Chapter Two: --- Materials and Methods --- p.49 / Chapter 2.1 --- Ethics approval --- p.50 / Chapter 2.2 --- Sample management --- p.50 / Chapter 2.2.1 --- Sample collection --- p.50 / Chapter 2.2.2 --- Sample storage and labelling --- p.50 / Chapter 2.3 --- DNA extraction --- p.51 / Chapter 2.3.1 --- Physical extraction 226}0ؤ heating --- p.51 / Chapter 2.3.2 --- Chemical extraction - Qiagen kit extraction --- p.51 / Chapter 2.4 --- Polymerase chain reaction --- p.53 / Chapter 2.4.1 --- Controls for polymerase chain reaction --- p.53 / Chapter 2.4.2 --- Beta-globin polymerase chain reaction --- p.53 / Chapter 2.4.3 --- HPV 52-specific human papillomavirus polymerase chain reaction --- p.56 / Chapter 2.4.4 --- Consensus human papillomavirus L1 open-reading frame polymerase chain reaction --- p.57 / Chapter 2.4.4.1 --- GP5+/6+ polymerase chain reaction --- p.57 / Chapter 2.4.4.2 --- MY09/11 polymerase chain reaction --- p.60 / Chapter 2.4.4.3 --- PGMY09/11 polymerase chain reaction --- p.63 / Chapter 2.5 --- Genotyping of human papillomavirus --- p.65 / Chapter 2.5.1 --- Restriction fragment length polymorphism --- p.65 / Chapter 2.5.2 --- Reverse line-blot hybridization --- p.67 / Chapter 2.6 --- Sequencing --- p.69 / Chapter 2.6.1 --- Sequencing for HPV genotyping --- p.69 / Chapter 2.6.2 --- Sequencing of HPV 52 E6 and E7 genes --- p.69 / Chapter 2.7 --- Statistical analysis --- p.70 / Chapter Chapter Three --- Study I 226}0ؤ Comparison of Three HPV DNA Detection Methods --- p.71 / Chapter 3.1 --- Objective --- p.72 / Chapter 3.2 --- Study plan --- p.72 / Chapter 3.3 --- Results --- p.74 / Chapter 3.3.1 --- Study population --- p.74 / Chapter 3.3.2 --- Optimisation of polymerase chain reactions --- p.74 / Chapter 3.3.3 --- Method 1: GP5+/6+ PCR followed by cycle sequencing --- p.76 / Chapter 3.3.4 --- Method 2: MY09/11 PCR followed by restriction fragment length polymorphism --- p.76 / Chapter 3.3.5 --- Method 3: PGMY09/11 PCR followed by reverse line-blot hybridization --- p.77 / Chapter 3.3.6 --- Prevalence and genotype distribution of human papillomavirus infection in cervical cancer patients --- p.81 / Chapter 3.3.7 --- Detection of multiple infections --- p.81 / Chapter 3.3.8 --- Sensitivity of the detection methods --- p.82 / Chapter 3.3.9 --- Comparison of prevalence rates of human papillomavirus genotypes --- p.82 / Chapter 3.3.10 --- Comparison of genotype distribution in Hong Kong cervical cancer patients with other geographic regions --- p.83 / Chapter 3.3.11 --- Follow-up investigation of GP5+/6+ primer binding site in HPV 52 --- p.84 / Chapter 3.4 --- Discussion --- p.91 / Chapter Chapter Four --- Study II - Post-treatment Follow-up Study on Patients with High-grade Cervical Lesions --- p.95 / Chapter 4.1 --- Objective --- p.96 / Chapter 4.2 --- Study plan --- p.96 / Chapter 4.3 --- Results --- p.97 / Chapter 4.3.1 --- Study population --- p.97 / Chapter 4.3.2 --- The prevalence and genotype distribution of human papillomavirus infection before treatment --- p.98 / Chapter 4.3.3 --- Persistent human papillomavirus infection --- p.99 / Chapter 4.3.4 --- Risk-factors associated with persistent human papillomavirus infection --- p.99 / Chapter 4.3.4.1 --- Excision margin status --- p.99 / Chapter 4.3.4.2 --- Multiple human papillomavirus infections --- p.99 / Chapter 4.4 --- Discussion --- p.108 / Chapter 4.4.1 --- Prevalence and genotype distribution of human papillomavirus in high-grade cervical neoplasia --- p.108 / Chapter 4.4.2 --- Risk factors for cervical intraepithelial neoplasia recurrence --- p.110 / Chapter Chapter Five --- Study III - Investigation of Human Papillomavirus 52 Sequence Variation --- p.115 / Chapter 5.1 --- Objective --- p.116 / Chapter 5.2 --- Study plan --- p.116 / Chapter 5.3 --- Results --- p.117 / Chapter 5.3.1 --- Study population --- p.117 / Chapter 5.3.2 --- Nucleotide sequence variations --- p.119 / Chapter 5.3.2.1 --- Human papillomavirus 52 E6 open-reading frame --- p.119 / Chapter 5.3.2.2 --- Human papillomavirus 52 E7 open-reading frame --- p.123 / Chapter 5.3.2.3 --- Comparison of nucleotide sequence variations in HPV 52 E6 and E7 open-reading frame --- p.128 / Chapter 5.4 --- Discussion --- p.134 / References --- p.137

Les infections à Papillomavirus Humain (HPV) sont des infections sexuellement transmissibles très fréquentes. La persistance de ces infections est un facteur causal du cancer du col de l’utérus et est aussi à l’origine d’autres cancers de la zone ano-génitale et de verrues génitales chez les femmes et chez les hommes. Depuis l’introduction de deux vaccins bivalent et quadrivalent permettant de prévenir certains types d’HPV, de nombreux modèles mathématiques ont été développés afin d’estimer l’impact potentiel de différentes stratégies de vaccination. L’objectif de ce travail de thèse a été d’estimer l’impact potentiel de la vaccination en France sur l’incidence de certains cancers liés à l’HPV, notamment le cancer du col de l’utérus et le cancer anal chez les femmes françaises ; ainsi que sur la prévalence des infections à HPV 6/11/16/18. Différents modèles dynamiques de type déterministe ont été développés. Ils sont représentés par des systèmes d’équations différentielles ordinaires. Une étude théorique du comportement asymptotique d’un premier modèle comportant peu de strates a été réalisée. Le nombre de reproduction de base R0 et le nombre de reproduction avec vaccination Rv ont été estimés. Des modèles plus complexes ont intégré une structure d’âge et de comportement sexuel. Les modélisations réalisées permettent de conclure à l’impact important de la vaccination sur la prévalence des infections à HPV et sur l’incidence des cancers du col de l’utérus et de la zone anale chez les femmes françaises dans un délai de quelques décennies, si l’on prend en compte les taux de vaccination observés en France au début de la campagne de vaccination / Human Papillomavirus infection (HPV) is the most frequent sexually transmitted disease. Epidemiological studies have established a causal relationship between HPV infections and occurence of cervical cancer. These infections have also been incriminated in anogenital cancers and anogenital warts among women and men. Since the introduction of bivalent and quadrivalent vaccines which offer protection against some HPV genotypes, many mathematical models have been developed in order to assess the potential impact of vaccine strategies. The aim of this thesis work was to assess the potential impact of HPV vaccination in France on the incidence of some cancers linked with HPV, particularly cervical cancer and anal cancer in French women, and on the prevalence of HPV 6/11/16/18 infections. Different deterministic dynamic models have been developped. They are represented by systems of ordinary differential equations. A theoretical analysis of the asymptotic behavior for a first model with few strata is realized. The basic reproduction number R0 and the vaccinated reproduction number Rv are assessed. More complex models taking into account age and sexual behavior have been developed. Using vaccination rates observed in France at the launch of the vaccination campaign, our modeling shows the large impact of vaccination on HPV prevalences, on cervical cancer and anal cancer incidences among French women within a few decades