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1.
FASEB J ; 38(13): e23741, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38896550

RESUMO

Access to scientific meetings and conferences is limited in low- and middle-income countries (LMIC). Efforts are being implemented to rectify this issue through short workshops, seminars, and conferences. Sena Institute of Technology (SIT), a nonprofit research institute based in Ghana, is one such organization championing this initiative. Through a partnership with the Federation of American Societies for Experimental Biology (FASEB), SIT hosted the first FASEB conference in Africa from August 27-30, 2023 in Ghana. The 3-day conference brought together scientists specialized in imaging, genetics, and cell biology from across the globe to discuss the theme "Imaging Cellular and Chromosome Dynamics." The Ghanaian Ministry of Environment, Science, Technology and Innovation (MESTI) and the Ghana Tourism Authority (GTA) provided local support to the meeting. At the end of the conference, participants recommended continuing engagement and the organization of more such meetings on the African continent.


Assuntos
Cromossomos , Humanos , Gana , Congressos como Assunto
3.
Germs ; 11(4): 468-477, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35096665
4.
Int J Mol Sci ; 20(21)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683862

RESUMO

Mucosotropic human papillomaviruses (HPVs) cause prevalent anogenital infections, some of which can progress to cancers. It is imperative to identify efficacious drug candidates, as there are few therapeutic options. We have recapitulated a robust productive program of HPV-18 in organotypic raft cultures of primary human keratinocytes. The HPV E7 protein induces S phase reentry, along with DNA damage response (DDR) in differentiated cells to support viral DNA amplification. A number of small molecule inhibitors of DDR regulators are in clinical use or clinical trials to treat cancers. Here, we used our raft culture system to examine effects of inhibitors of ATR/Chk1 and ATM/Chk2 on HPV infection. The inhibitors impaired S-phase reentry and progression as well as HPV DNA amplification. The Chk1 inhibitor MK-8776 was most effective, reducing viral DNA amplification by 90-99% and caused DNA damage and apoptosis, preferentially in HPV infected cells. We found that this sensitivity was imparted by the E7 protein and report that MK-8776 also caused extensive cell death of cervical cancer cell lines. Furthermore, it sensitized the cells to cisplatin, commonly used to treat advanced cervical cancer. Based on these observations, the Chk1 inhibitors could be potential effective agents to be re-purposed to treat the spectrum of HPV infections in single or combination therapy.


Assuntos
DNA Viral/antagonistas & inibidores , Papillomavirus Humano 18/metabolismo , Queratinócitos/efeitos dos fármacos , Proteínas E7 de Papillomavirus/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Replicação Viral/efeitos dos fármacos , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Cisplatino/farmacologia , DNA Viral/genética , DNA Viral/metabolismo , Feminino , Células HeLa , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/fisiologia , Humanos , Queratinócitos/metabolismo , Queratinócitos/virologia , Masculino , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/virologia , Inibidores de Proteínas Quinases/farmacologia , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Replicação Viral/genética
6.
Proc Natl Acad Sci U S A ; 115(47): E11138-E11147, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30385631

RESUMO

Human papillomaviruses (HPVs) cause epithelial proliferative diseases. Persistent infection of the mucosal epithelia by the high-risk genotypes can progress to high-grade dysplasia and cancers. Viral transcription and protein activities are intimately linked to regulation by histone acetyltransferases and histone deacetylases (HDACs) that remodel chromatin and regulate gene expression. HDACs are also essential to remodel and repair replicating chromatin to enable the progression of replication forks. As such, Vorinostat (suberoylanilide hydroximic acid), and other pan-HDAC inhibitors, are used to treat lymphomas. Here, we investigated the effects of Vorinostat on productive infection of the high-risk HPV-18 in organotypic cultures of primary human keratinocytes. HPV DNA amplifies in the postmitotic, differentiated cells of squamous epithelia, in which the viral oncoproteins E7 and E6 establish a permissive milieu by destabilizing major tumor suppressors, the pRB family proteins and p53, respectively. We showed that Vorinostat significantly reduced these E6 and E7 activities, abrogated viral DNA amplification, and inhibited host DNA replication. The E7-induced DNA damage response, which is critical for both events, was also compromised. Consequently, Vorinostat exposure led to DNA damage and triggered apoptosis in HPV-infected, differentiated cells, whereas uninfected tissues were spared. Apoptosis was attributed to highly elevated proapoptotic Bim isoforms that are known to be repressed by EZH2 in a repressor complex containing HDACs. Two other HDAC inhibitors, Belinostat and Panobinostat, also inhibited viral DNA amplification and cause apoptosis. We suggest that HDAC inhibitors are promising therapeutic agents to treat benign HPV infections, abrogate progeny virus production, and hence interrupt transmission.


Assuntos
Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Papillomavirus Humano 18/genética , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/tratamento farmacológico , Vorinostat/farmacologia , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Células Cultivadas , Reparo do DNA/efeitos dos fármacos , DNA Viral/genética , Histonas/metabolismo , Papillomavirus Humano 18/efeitos dos fármacos , Humanos , Ácidos Hidroxâmicos/farmacologia , Queratinócitos/virologia , Mucosa/virologia , Panobinostat/farmacologia , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/transmissão , Sulfonamidas/farmacologia , Proteína Supressora de Tumor p53/metabolismo
7.
J Med Chem ; 59(23): 10470-10478, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27933957

RESUMO

Human papillomavirus (HPV) high-risk genotypes such as HPV-16 and HPV-18 cause the majority of anogenital tract carcinomas, including cervical cancer, the second most common malignancy in women worldwide. Currently there are no approved antiviral agents that reduce or eliminate HPV and reverse virus-associated pathology. We synthesized and evaluated several alkoxyalkyl acyclic nucleoside phosphonate diesters and identified octadecyloxyethyl benzyl 9-[(2-phosphonomethoxy)ethyl]guanine (ODE-Bn-PMEG) as an active compound which strongly inhibited transient amplification of HPV-11, -16, and -18 origin-containing plasmid DNA in transfected cells at concentrations well below its cytotoxic concentrations. ODE-Bn-PMEG demonstrated increased uptake in human foreskin fibroblast cells and was readily converted in vitro to the active antiviral metabolite, PMEG diphosphate. The P-chiral enantiomers of ODE-Bn-PMEG were obtained and appeared to have equivalent antiviral activities against HPV. ODE-Bn-PMEG is a promising candidate for the local treatment of HPV-16 and HPV-18 and other high-risk types, an important unmet medical need.


Assuntos
Antivirais/farmacologia , DNA Viral/efeitos dos fármacos , Guanina/análogos & derivados , Técnicas de Amplificação de Ácido Nucleico , Organofosfonatos/farmacologia , Papillomaviridae/efeitos dos fármacos , Antivirais/síntese química , Antivirais/química , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Guanina/síntese química , Guanina/química , Guanina/farmacologia , Células HEK293 , HIV/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/virologia , Estrutura Molecular , Organofosfonatos/síntese química , Organofosfonatos/química , Papillomaviridae/genética , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
8.
Infect Genet Evol ; 46: 7-11, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27725301

RESUMO

OBJECTIVES/BACKGROUND: Sequence variants in HPV16 confer differences in oncogenic potential; however, to date there have not been any HPV sequence studies performed in Nepal. The objective of this study was to characterize HPV16 viral genome sequences from Nepal compared to a reference sequence in order to determine their lineages. Additionally, we sought to determine if five High-grade Squamous Intraepithelial Lesion (HSIL) subjects were genetically distinct from the non-HSIL subjects. METHODS: DNA was isolated from exfoliated cervical cells from 17 individuals in Nepal who were previously identified to be HPV16-positive. A custom HPV16 Ion Ampliseq panel of multiplexed degenerate primers was designed that generated 47 overlapping amplicons and covered 99% of the viral genome for all known HPV16 variant lineages. All sequence data were processed through a custom quality control and analysis pipeline of sequence comparisons and phylogenetic analysis. RESULTS: There were high similarities across the genomes, with two major indels observed in the non-coding region between E5 and L2. Compared to the PAVE reference HPV16 genome, there were up to 9, 4, 38, 27, 8, 7, 52, and 32 nucleotide variants in the E6, E7, E1, E2, E4, E5, L2, and L1 genes in the Nepalese samples, respectively. Based on sequence variation, HPV16 from Nepal falls across the A, C, and D lineages in this study. We found no evidence of genetic distinctness between HSIL and non-HSIL subjects. CONCLUSIONS: The evolutionary and pathological characteristics of the representative HPV16 genomes from Nepal seem similar to results from other parts of the world and provide the basis for further studies.


Assuntos
Papillomavirus Humano 16/classificação , Papillomavirus Humano 16/genética , Infecções por Papillomavirus/virologia , Colo do Útero/virologia , Estudos de Coortes , Feminino , Genoma Viral/genética , Humanos , Epidemiologia Molecular , Nepal/epidemiologia , Infecções por Papillomavirus/epidemiologia , Filogenia , Doenças Uterinas/epidemiologia , Doenças Uterinas/virologia
9.
Vaccine ; 34(27): 3171-3177, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27113165

RESUMO

The prevalent human papillomaviruses (HPVs) infect human epithelial tissues. Infections by the mucosotropic HPV genotypes cause hyperproliferative ano-genital lesions. Persistent infections by high-risk (HR) HPVs such as HPV-16, HPV-18 and related types can progress to high grade intraepithelial neoplasias and cancers. Prophylactic HPV vaccines are based on DNA-free virus-like particles (VLPs) composed of the major capsid protein L1 of HPV-16, -18, -6 and -11 (Gardasil) or HPV-16 and -18 (Cervarix). Sera from vaccinated animals effectively prevent HPV pseudovirions to infect cell lines and mouse cervical epithelia. Both vaccines have proven to be highly protective in people. HPV pseudovirions are assembled in HEK293TT cells from matched L1 and L2 capsid proteins to encapsidate a reporter gene. Pseudovirions and genuine virions have structural differences and they infect cell lines or primary human keratinocytes (PHKs) with different efficiencies. In this study, we show that sera and isolated IgG from women immunized with Gardasil prevent authentic HPV-18 virions from infecting PHKs, whereas non-immune sera and purified IgG thereof are uniformly ineffective. Using early passage PHKs, neutralization is achieved only if immune sera are added within 2-4h of infection. We attribute the timing effect to a conformational change in HPV virions, thought to occur upon initial binding to heparan sulfate proteoglycans (HSPG) on the cell surface. This interpretation is consistent with the inability of immune IgG bound to or taken up by PHKs to neutralize the virus. Interestingly, the window of neutralization increases to 12-16h in slow growing, late passage PHKs, suggestive of altered cell surface molecules. In vivo, this window might be further lengthened by the time required to activate the normally quiescent basal cells to become susceptible to infection. Our observations help explain the high efficacy of HPV vaccines.


Assuntos
Anticorpos Antivirais/imunologia , Vacina Quadrivalente Recombinante contra HPV tipos 6, 11, 16, 18/uso terapêutico , Soros Imunes/imunologia , Queratinócitos/virologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Células Cultivadas , Feminino , Proteoglicanas de Heparan Sulfato/metabolismo , Papillomavirus Humano 18 , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Testes de Neutralização , Infecções por Papillomavirus/prevenção & controle
10.
Methods Mol Biol ; 1249: 93-109, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25348300

RESUMO

The productive program of the human papillomaviruses takes place in terminally differentiating squamous epithelia. In this chapter, we provide the protocols for robust production of HPV-18 in organotypic cultures of early passages of primary human keratinocytes. A critical step is the generation of genomic HPV plasmids in vivo by using Cre-loxP-mediated excisional recombination from a vector plasmid. We discuss the rationale for this approach. This system produces high yields of infectious virus and facilitates genetic analyses of HPV protein functions and their regulation in the context of recapitulated host tissue environment.


Assuntos
Técnicas de Cultura de Células/métodos , Papillomavirus Humano 18/crescimento & desenvolvimento , Queratinócitos/virologia , Animais , Sítios de Ligação Microbiológicos/genética , Proteínas do Capsídeo/metabolismo , Separação Celular , Células Cultivadas , DNA Viral/genética , DNA Viral/isolamento & purificação , Genoma Viral , Humanos , Camundongos , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transfecção , Vírion/metabolismo
11.
PLoS One ; 9(6): e101255, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24978811

RESUMO

INTRODUCTION: Nepal has one of the highest cervical cancer rates in South Asia. Only a few studies in populations from urban areas have investigated type specific distribution of human papillomavirus (HPV) in Nepali women. Data on high-risk HPV (HR-HPV) types are not currently available for rural populations in Nepal. We aimed to assess the distribution of HR- HPV among rural Nepali women while assessing self-collected and clinician-collected cervico-vaginal specimens as sample collection methods for HPV screening. METHODS: Study participants were recruited during a health camp conducted by Nepal Fertility Care Center in Achham District of rural far western Nepal. Women of reproductive age completed a socio-demographic and clinical questionnaire, and provided two specimens; one cervical-vaginal specimen using a self-collection method and another cervical specimen collected by health camp auxiliary nurse midwives during a pelvic examination. All samples were tested for 14 different HR-HPV mRNA and also specific for HPV16/18/45 mRNA. RESULTS: Of 261 women with both clinician- and self-collected cervical samples, 25 tested positive for HR-HPV, resulting in an overall HR-HPV prevalence of 9.6% (95% confidence Interval [CI]: 6.3-13.8). The overall Kappa value assessing agreement between clinician- and self-collected tests was 0.62 (95% CI: 0.43-0.81), indicating a "good" level of agreement. Abnormal cytology was reported for 8 women. One woman identified with squamous cell carcinoma (SCC), and 7 women with high grade squamous intraepithelial lesions (HSIL). Seven of the 8 women tested positive for HR-HPV (87.5%) in clinician-collected samples and 6 in self-collected samples (75.0%). CONCLUSION: This is the first study to assess HR-HPV among rural Nepali women. Self-collected sampling methods should be the subject of additional research in Nepal for screening HR-HPV, associated with pre-cancer lesions and cancer, in women in rural areas with limited access to health services.


Assuntos
Pessoal de Laboratório Médico/estatística & dados numéricos , Papillomaviridae/fisiologia , Infecções por Papillomavirus/epidemiologia , Medição de Risco , População Rural/estatística & dados numéricos , Manejo de Espécimes/métodos , Esfregaço Vaginal/métodos , Adolescente , Adulto , Comportamento , Demografia , Feminino , Humanos , Pessoa de Meia-Idade , Nepal/epidemiologia , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Prevalência , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tamanho da Amostra , Adulto Jovem
12.
Vaccine ; 31 Suppl 5: F1-31, 2013 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-24331745

RESUMO

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters.


Assuntos
Neoplasias do Ânus/prevenção & controle , Neoplasias Orofaríngeas/prevenção & controle , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/prevenção & controle , Neoplasias Penianas/prevenção & controle , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias Vaginais/prevenção & controle , Neoplasias do Ânus/epidemiologia , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/estatística & dados numéricos , Feminino , Humanos , Masculino , Neoplasias Orofaríngeas/epidemiologia , Infecções por Papillomavirus/epidemiologia , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/imunologia , Neoplasias Penianas/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Vacinação/estatística & dados numéricos , Neoplasias Vaginais/epidemiologia
13.
Vaccine ; 31 Suppl 6: G1-31, 2013 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-24331817

RESUMO

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters.

14.
Vaccine ; 31 Suppl 7: H1-31, 2013 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-24332295

RESUMO

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters.

15.
Vaccine ; 31 Suppl 8: I1-31, 2013 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-24229716

RESUMO

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters.


Assuntos
Detecção Precoce de Câncer/métodos , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/imunologia , Neoplasias do Ânus/epidemiologia , Neoplasias do Ânus/etiologia , Neoplasias do Ânus/prevenção & controle , Feminino , Saúde Global , Humanos , Masculino , Neoplasias Orofaríngeas/epidemiologia , Neoplasias Orofaríngeas/etiologia , Neoplasias Orofaríngeas/prevenção & controle , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Neoplasias Penianas/epidemiologia , Neoplasias Penianas/etiologia , Neoplasias Penianas/prevenção & controle , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/etiologia , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias Vulvares/epidemiologia , Neoplasias Vulvares/etiologia , Neoplasias Vulvares/prevenção & controle
16.
Artigo em Inglês | MEDLINE | ID: mdl-23685995

RESUMO

Human papillomaviruses (HPVs) are prevalent pathogens of mucosal and cutaneous epithelia. Productive infections of squamous epithelia lead to benign hyperproliferative warts, condylomata, or papillomas. Persistent infections of the anogenital mucosa by high-risk HPV genotypes 16 and 18 and closely related types can infrequently progress to high-grade intraepithelial neoplasias, carcinomas-in-situ, and invasive cancers in women and men. HPV-16 is also associated with a fraction of head and neck cancers. We discuss the interactions of the mucosotropic HPVs with the host regulatory proteins and pathways that lead to benign coexistence and enable HPV DNA amplification or, alternatively, to cancers that no longer support viral production.


Assuntos
Alphapapillomavirus/genética , Infecções por Papillomavirus/genética , Neoplasias do Colo do Útero/virologia , Verrugas/virologia , Alphapapillomavirus/fisiologia , Feminino , Genoma Viral , Genótipo , Interações Hospedeiro-Patógeno , Humanos , Masculino , Neoplasias do Colo do Útero/genética , Replicação Viral , Verrugas/genética
17.
Proc Natl Acad Sci U S A ; 110(19): 7542-9, 2013 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-23572574

RESUMO

Human papillomaviruses (HPVs) amplify in differentiated strata of a squamous epithelium. The HPV E7 protein destabilizes the p130/retinoblastoma susceptibility protein family of tumor suppressors and reactivates S-phase reentry, thereby facilitating viral DNA amplification. The high-risk HPV E6 protein destabilizes the p53 tumor suppressor and many other host proteins. However, the critical E6 targets relevant to viral DNA amplification have not been identified, because functionally significant E6 mutants are not stably maintained in transfected cells. Using Cre-loxP recombination, which efficiently generates HPV genomic plasmids in transfected primary human keratinocytes, we have recapitulated a highly productive infection of HPV-18 in organotypic epithelial cultures. By using this system, we now report the characterization of four HPV-18 E6 mutations. An E6 null mutant accumulated high levels of p53 and amplified very poorly. p53 siRNA or ectopic WT E6 partially restored amplification, whereas three missense E6 mutations that did not effectively destabilize p53 complemented the null mutant poorly. Unexpectedly, in cis, two of the missense mutants amplified, albeit to a lower extent than the WT and only in cells with undetectable p53. These observations and others implicate p53 and additional host proteins in regulating viral DNA amplification and also suggest an inhibitory effect of E6 overexpression. We show that high levels of viral DNA amplification are critical for late protein expression and report several previously undescribed viral RNAs, including bicistronic transcripts predicted to encode E5 and L2 or an alternative form of E1^E4 and L1.


Assuntos
DNA Viral/metabolismo , Proteínas de Ligação a DNA/genética , Genes p53 , Papillomavirus Humano 18/genética , Mutação , Proteínas Oncogênicas Virais/genética , Células Cultivadas , Genes Supressores de Tumor , Teste de Complementação Genética , Genoma Viral , Humanos , Integrases/metabolismo , Queratinócitos/citologia , Mutação de Sentido Incorreto , Fenótipo , Plasmídeos/metabolismo , RNA Interferente Pequeno/metabolismo , Proteína Supressora de Tumor p53/metabolismo
18.
Vaccine ; 30 Suppl 5: F175-82, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23199961

RESUMO

The recognition that human papillomavirus (HPV) infection is the central, necessary cause of cervical cancer paved the way to new fronts of prevention via improved screening methods and HPV vaccination. Much has been learned in all fronts, from the molecular basis of our understanding of how HPV causes disease to the health economics of preventive strategies at the individual and population levels. Progress in other areas of cancer control has yet to show the same multi- and trans-disciplinary gains seen in research on HPV-associated malignancies, which is one of the unequivocal success stories in disease prevention. Yet, as an embarrassment of riches, much more research is needed to fill the gaps in knowledge that remain before we are able to reap the benefits from the knowledge translation from all fronts. Public health research on setting-specific implementation of HPV-based preventive strategies and more concerted advocacy to counter barriers facing the adoption of these strategies are likely to yield major dividends in reducing the burden of HPV-associated diseases. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.


Assuntos
Neoplasias/epidemiologia , Neoplasias/prevenção & controle , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Detecção Precoce de Câncer/métodos , Política de Saúde , Humanos , Vacinas contra Papillomavirus/administração & dosagem
19.
Vaccine ; 30 Suppl 5: F71-82, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23199967

RESUMO

This chapter reviews the current treatment of chronic and neoplastic human papillomavirus (HPV)-associated conditions and the development of novel therapeutic approaches. Surgical excision of HPV-associated lower genital tract neoplasia is very successful but largely depends on secondary prevention programmes for identification of disease. Only high-risk HPV-driven chronic, pre-neoplastic lesions and some very early cancers cannot be successfully treated by surgical procedures alone. Chemoradiation therapy of cervical cancer contributes to the 66-79% cervical cancer survival at 5 years. Outlook for those patients with persistent or recurrent cervical cancer following treatment is very poor. Topical agents such as imiquimod (immune response modifier), cidofovir (inhibition of viral replication; induction apoptosis) or photodynamic therapy (direct damage of tumour and augmentation of anti-tumour immunity) have all shown some useful efficacy (~50-60%) in treatment of high grade vulvar intraepithelial neoplasia (VIN). Provider administered treatments of genital warts include cryotherapy, trichloracetic acid, or surgical removal which has the highest primary clearance rate. Patient applied therapies include podophyllotoxin and imiquimod. Recurrence after "successful" treatment is 30-40%. Further improvements could derive from a rational combination of current therapy with new drugs targeting molecular pathways mediated by HPV in cancer. Small molecule inhibitors targeting the DNA binding activities of HPV E1/E2 or the anti-apoptotic consequences of E6/E7 oncogenes are in preclinical development. Proteasome and histone deacetylase inhibitors, which can enhance apoptosis in HPV positive tumour cells, are being tested in early clinical trials. Chronic high-risk HPV infection/neoplasia is characterised by systemic and/or local immune suppressive regulatory or escape factors. Recently two E6/E7 vaccines have shown some clinical efficacy in high grade VIN patients and this correlated with strong and broad systemic HPV-specific T cell response and modulation of key local immune factors. Treatments that can shift the balance of immune effectors locally in combination with vaccination are now being tested. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.


Assuntos
Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/terapia , Antivirais/administração & dosagem , Crioterapia/métodos , Tratamento Farmacológico/métodos , Feminino , Neoplasias dos Genitais Femininos/cirurgia , Neoplasias dos Genitais Femininos/virologia , Neoplasias dos Genitais Masculinos/cirurgia , Neoplasias dos Genitais Masculinos/virologia , Humanos , Imunomodulação , Masculino , Vacinas contra Papillomavirus/administração & dosagem , Radioterapia/métodos
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