Made available in DSpace on 2016-08-10T10:38:42Z (GMT). No. of bitstreams: 1 ELIANE DA SILVA RIBEIRO.pdf: 1086550 bytes, checksum: fdf51565bf5bda0fc2d8aacfc69c4ef8 (MD5) Previous issue date: 2012-06-29 / Persistent Human Papillomavirus (HPV) high risk, is the most important risk factor for development of cervical cancer. However, only high risk HPV types are associated with cancer. This ability carcinogenic due to interaction between HPV E6 protein with p53 protein, considered the main event of this process of tumor development. The present study evaluated the genotypes of HPV; Sequencing of the fragment coding the polymorphism Arg72Pro TP53, the association of these factors together with the radiosensitivity of patients with cervical cancer in selected Radiotherapy Service, Hospital Jorge Araujo, the ACCG. Twenty-seven patients with cervical cancer referred for radiotherapy were selected for this prospective study. DNA was extracted from cells harvested with cervical squamous cytobrush. Was performed HPV genotyping by reverse hybridization and evaluation of the presence of TP53 polymorphism was performed by sequencing of fragment Arg72Pro. Data were evaluated according to the average age, level of differentiation do tumor, clinical stage of the tumor and the incidence of side effects according to the criteria of the Radiation Therapy Oncology Group (RTOG). Statistical analysis was performed using SPSS 17.0 for Windows. The mean age of patients was 54 years (± 16.3). The incidence of acute side effects (RTOG) were reactions in the lower gastrointestinal tract (GIT): grade 0-1 (59.6%) and ≥ grade 2 (40.4%); reactions tract genitourinary (TGU): degree 0-1 (86.4%) and ≥ grade 2 (13.6%). The degree of acute toxicity TGI ≥ 2 was related to the age where the patients ≥ 50 years old, had a relative risk of 1.8 times greater (1.1 - 2.8; 95%) of radiosensitivity and infection with multiple HPV types, a relative risk 2.6 times higher (0.8 to 8.2, 95% CI). Therapeutic response after two months of treatment: 16 (59.3%) patients with complete remission, seven (25.9%) with active disease / death. The presence of HPV was observed in 26 (96.3%) patients, HPV genotype was more prevalent HPV 16 (61.5%), followed by HPV 52 (19.2%) and HPV 18 (11.5% ). Infection of a single HPV type was observed in 19 (73.1%) and seven (26.9%) had more than one HPV genotype. We observed the presence of genotype Arg / Arg in eight (33.3%), Arg / Pro in 15 (62.5%) and Pro / Pro in one (4.2%). Patients with genotype (Arg / Arg) had a higher risk of having multiple virus infection (RR = 1.77, 1.15 to 2.73, p = 0.04). And this multiple coinfection with an increased risk of severe acute radiosensitivity in the GIT, with a relative risk of 2.6 times greater (p=0,03). / A persistência do Papilomavírus Humano (HPV) de alto risco, é o mais importante fator de risco para o desenvolvimento do câncer de colo uterino. Contudo, apenas os HPV de alto risco estão associados ao câncer. Esta habilidade carcinogênica deve-se a interação entre a proteína E6 do HPV com proteína p53, considerado o principal evento deste processo do desenvolvimento de tumores. O presente estudo avaliou os genótipos dos HPV; O sequenciamento do fragmento que contém o polimorfismo Arg72Pro do gene TP53; A associação destes fatores entre si com a radiossensibilidade das pacientes com câncer de colo uterino selecionadas no Serviço de Radioterapia, do Hospital Araujo Jorge, da ACCG. Vinte e sete pacientes com câncer de colo uterino encaminhadas para a radioterapia foram selecionadas para este estudo prospectivo. O DNA foi extraído de células descamativas cervicais colhidas com cytobrush. Foi realizada a genotipagem do HPV através da hibridização reversa e a avaliação da presença do polimorfismo Tp53 foi realizada pelo sequenciamento do fragmento Arg72Pro. Os dados foram avaliados de acordo com a média de idade, grau de diferenciação do tumor, estadiamento clínico do tumor e incidência de efeitos colaterais de acordo com os critérios do Radiation Therapy Oncology Group (RTOG). A análise estatística foi realizada utilizando o software SPSS 17.0 para Windows. A média de idade das pacientes foi de 54 anos (±16,3). A incidência de efeitos colaterais agudos (RTOG) foram: reações no trato gastrointestinal inferior(TGI): grau 0 1 (59,6%) e grau ≥2 (40,4%); reações no trato genuturinário (TGU): grau 0 - 1 (86,4%) e grau ≥2 (13,6%). O grau de toxicidade aguda ≥ 2 do TGI associou-se com a idade, onde as pacientes com ≥ 50 anos, apresentaram um risco relativo de 1,8 vezes maior (1,1 - 2,8; IC 95%) de radiossensibilidade e com infecção por múltiplos tipos de HPV, um risco relativo 2,6 vezes maior (0,8 - 8,2; IC 95%). A resposta terapêutica após dois meses do tratamento: 16 (59,3%) pacientes com remissão total da doença, sete (25,9%) com doença em atividade/óbito. A presença do HPV foi observada em 26 (96,3%) pacientes, o genótipo do HPV mais prevalente foi HPV 16 (61,5%), seguido pelo HPV 52 (19,2%) e HPV 18 (11,5%). A infecção por um único tipo de HPV foi observado em 19 (73,1%) pacientes e sete (26,9%) apresentavam mais de um genótipo de HPV. Observamos a presença do genótipo Arg/Arg em oito (33,3%), Arg/Pro em 15 (62,5%) e Pro/Pro em uma (4,2%). As pacientes com genótipo (Arg/Arg) apresentaram maior risco de ter infecção por múltiplos vírus (RR= 1,77; 1,15-2,73; p=0,04). E esta coinfecção múltipla com um maior risco de radiossensibilidade aguda grave no TGI , com um risco relativo de 2,6 vezes maior (p=0,03).

Made available in DSpace on 2016-08-10T10:39:12Z (GMT). No. of bitstreams: 1 NATHALIA AMARAL NOGUEIRA.pdf: 6074559 bytes, checksum: db2409d0f003801fe0f55ef172d6687e (MD5) Previous issue date: 2016-03-14 / In developing countries, uterine cervical cancer is responsible for a large percentage of deaths in middle-aged women, and presents high rates of incidence, especially due to the lack of efficient screening of precursor lesions and cancer. Biomarkers can increase the accuracy and effectiveness of screening programs, diagnosis and treatment of cervical cancer precursor lesions. Among the markers related to cell proliferation changes, p16INK4a excels. P16INK4aexpression may suggest the presence of transformed cells, in the lesions seemingly normal morphology, and it also predicts the faster development of neoplastic cells. The prognostic role of p16INK4a in cervical cancer is not clear. The effect of p16INK4a expression in the survival of cervical cancer patients has been investigated and the results are conflicting. The main objective of this study was to investigate the potential prognostic role of p16INK4a in cervical carcinomas. The series comprising 161 patients attended on Araújo Jorge Hospital - Goiânia, Goiás, Brazil - from 2006 to 2007, with histologically confirmed cervical cancer, assessed for p16INK4a expression by means of immunohistochemistry. The results were compared by Chi-square test or Fisher s exact test and survival analysis by Kaplan-Meier and Log-rank tests. Overexpression of p16INK4a was observed in 145 (90.0%) of the cases. No statistically significant association was observed between p16INK4a expression and clinical pathological aspects of cervical carcinomas. The overall survival for the group was 69.0%. When survival was evaluated in relation to p16INK4a expression, cases with overexpression showed a better survival rate (70.3%), towards those with low expression (56.2%), despite the difference between groups was not statistically significant. When compared in relation to clinical staging, cases with stage I and II showed a better survival (71.9%), compared to those with stage III and IV (54.8%) (p= 0.04), translating the best prognosis of cases diagnosed ealier. Our results do not confirm the association between the p16INK4a expression and prognosis of uterine cervical cancer. / Nos países em desenvolvimento, o câncer de colo uterino é responsável por grande porcentagem de mortes em mulheres de meia idade e apresenta altas taxas de incidência, especialmente devido à falta de prevenção eficiente de lesões precursoras ou de câncer inicial. Biomarcadores podem aumentar a acurácia e a efetividade de programas de rastreamento, diagnóstico e tratamento das lesões precursoras do câncer. Dentre os marcadores relacionados às alterações da proliferação celular, destaca-se p16INK4a, cuja expressão pode sugerir a presença de células transformadas, ainda que as lesões apresentem morfologia aparentemente normal, e traduzir a evolução mais rápida das células neoplásicas. O papel prognóstico de p16INK4a no câncer de colo uterino não é claro. O efeito da hiperexpressão da p16INK4a na sobrevida de pacientes com câncer de colo uterino tem sido investigado e os resultados são conflitantes. O principal objetivo deste estudo foi investigar o potencial papel prognóstico de p16INK4a em carcinomas de colo uterino. A casuística consistiu de 161 pacientes com câncer de colo uterino confirmados histologicamente e assistidos no Hospital Araújo Jorge, em Goiânia-GO, no período de 2006-2007. A avaliação da expressão de p16INK4a foi feita por meio de reação imuno-histoquímica. Os resultados foram comparados pelo teste do Chi-quadrado ou teste exato de Fisher e as análises de sobrevida pelos testes de Kaplan-Meier e Log-rank. Os resultados demonstraram a hiperexpressão de p16INK4a em 145 casos (90,0%), enquanto a hipoexpressão foi observada em 16 casos (10,0%). Nenhuma associação estatisticamente significativa foi observada entre a expressão de p16INK4a e os aspectos clinicopatológicos dos carcinomas de colo uterino avaliados. A sobrevida global para o grupo foi de 69,0%. Quando a sobrevida foi avaliada em relação à expressão de p16INK4a, observou-se que os casos com hiperexpressão apresentaram sobrevida de 70,3%, comparados aos de hipoexpressão que apresentaram sobrevida de 56,2%. A diferença entre os grupos não foi estatisticamente significativa. Com relação ao estadiamento clínico, observou-se que os casos com estádio I e II apresentaram melhor sobrevida (71,9%) em relação àqueles com estádio III e IV (54,8%) (p=0,04), traduzindo o melhor prognóstico dos casos diagnosticados mais precocemente. Nossos resultados não confirmaram a associação entre a expressão de p16INK4a e o prognóstico dos tumores avaliados.

Submitted by admin tede (tede@pucgoias.edu.br) on 2016-09-08T17:44:05Z No. of bitstreams: 1 ANA LÚCIA MUNARO TACCA.pdf: 3214178 bytes, checksum: 58c28e17365eb1264fc070c8b52bf41f (MD5) / Made available in DSpace on 2016-09-08T17:44:05Z (GMT). No. of bitstreams: 1 ANA LÚCIA MUNARO TACCA.pdf: 3214178 bytes, checksum: 58c28e17365eb1264fc070c8b52bf41f (MD5) Previous issue date: 2016-03-10 / The main risk factor for cervical cancer is infection with the Human Papillomavirus (HPV). However, other risk factors are required for the development of cervical cancer, among them, smoking and genetic susceptibility have been proven relevant. Enzymes named Glutathione-S-Transferase (GST) are responsible for the metabolism of tobacco carcinogens and the genes encoding these enzymes are highly polymorphic. The objective of this study was to compare the frequencies of GSTM1 and GSTT1 null polymorphisms in women with cervical cancer and in women with no history of cancer, as well as the possible associations between such genetic polymorphisms, cigarette smoking and the prognosis of cervical cancer. The series consisted of 135 patients with cervical cancer and 100 participants without cancer. Genotypes were investigated by means of polymerase chain reaction (PCR). The results were compared using the Chi-square test or Fisher's exact test, and survival analysis by Kaplan-Meier tests and Log-rank. Among the cases, the frequency for GSTM1 gene null polymorphism was 22,2%, and for the GSTT1 gene, it was 48,5%. Among the controls, the frequency of the GSTM1 gene null polymorphism was 45.0%, while for the GSTT1 gene null polymorphism it was 56.0%. Important association was demonstrated between smoking and cervical cancer (p= 0.0062; OR = 2.16). The results showed that the GSTM1 and GSTT1 null genotypes were not associated with cervical cancer in the population studied. In addition, GSTM1 genotype was significantly associated to a better prognosis of the tumors, decreasing the risk of metastasis (p= 0.014; OR = 3.45). The overall survival rate for the group was 78.5% and, when stratified by genotypes studied, survival was higher in patients with positive genotypes, indicating a higher risk of death in the presence of dual nullity (p= 0.031; RR = 2.458). / O principal fator de risco para o câncer do colo uterino é a infecção pelo Papilomavírus humano (HPV), porém, sabe-se que outros fatores são necessários para o desenvolvimento do câncer. Dentre os fatores estudados, destacam-se o tabagismo e os fatores de suscetibilidade genética. As enzimas denominadas Glutationas-S-Transferase (GST) são responsáveis pela metabolização dos carcinógenos do tabaco e os genes que codificam essas enzimas são altamente polimórficos. O principal objetivo deste estudo foi comparar as frequências dos polimorfismos nulos de GSTT1 e GSTM1 em mulheres com câncer de colo uterino e em mulheres sem história de câncer, bem como as possíveis associações entre os polimorfismos genéticos, o tabagismo e o prognóstico dos tumores de colo uterino. A casuística consistiu de 135 pacientes com câncer e 100 participantes sem câncer. Os genótipos foram investigados por meio de reação em cadeia da polimerase (PCR). Os resultados foram comparados pelo teste Chi-quadrado ou teste exato de Fisher e as análises de sobrevida pelos testes de Kaplan-Meier e comparadas por Log-rank. Entre os casos, a frequência do polimorfismo nulo para o gene GSTM1 foi de 22,2% e para o gene GSTT1 foi de 48,5%. Entre os controles, a frequência do polimorfismo nulo no gene GSTM1 foi de 45,0%, enquanto para o gene GSTT1 nulo foi de 56,0%. Importante relação entre o hábito tabagista e o câncer do colo uterino foi observada (p=0,0062; OR=2,16). Os resultados demonstraram que os genótipos nulos de GSTM1 e GSTT1 não conferiram risco para o câncer cervical na população estudada. Além disso, o genótipo GSTM1 presente esteve associado significativamente ao melhor prognóstico dos tumores, diminuindo o risco de metástases (p=0,014; OR=3,45). A sobrevida global foi de 78,5% e, quando estratificada pelos genótipos estudados, foi superior em pacientes com genótipos positivos, indicando maior risco de óbito na presença de dupla nulidade (p=0,031; RR=2,458).

Introdução: A relação causal entre infecção genital por papilomavirus humano (HPV) de alto risco e o câncer do colo uterino está bem estabelecida; porém, há controvérsias em diferentes populações quanto à prevalência e distribuição da infecção em relação à idade. Objetivos: Caracterizar, pela Captura Híbrida II (CHII), a prevalência da infecção genital por HPV de alto risco e sua estratificação por idade. Verificar a associação da infecção com fatores de risco, resultados da citologia oncológica (CO), da colposcopia e da biópsia cervical. Casuística e Métodos: Em estudo transversal estudou-se 2300 mulheres (15-65 anos) que buscaram rastreamento para o câncer cervical. Aplicou-se questionário epidemiológico e foi feita a coleta da CO e da CHII, no caso de alteração em destes exames ou ambos indicou-se colposcopia e, nos casos anormais, procedeu-se à biópsia cervical. Resultados: A prevalência da infecção genital por HPV de alto risco em toda amostra foi de 17,8%: 27% (<25 anos), 21% (25-34 anos), 12% (35-54 anos) e de 14% (55-65 anos). Participantes com maior número de parceiros sexuais durante a vida apresentaram uma maior chance de infecção, relacionamento estável, idade entre 30 a 54 anos e ser ex-fumante foram fatores associados à proteção da infecção. Encontrou-se 204 (8,8%) CO anormais e uma relação direta entre severidade do diagnostico citológico e infecção por HPV de alto risco, 14,3% em citologia normal, 78% em lesão escamosa de alto grau, 100% nos esfregaços compatíveis com carcinoma. Foram histologicamente confirmados: 10 casos de Neoplasia intra-cervical grau 2/3 (NIC2/3) entre as mulheres infectadas por HPV, com citologia normal; 4 NIC 2/3 e um carcinoma nas que apresentavam exclusivamente alteração citológica e 15 NIC 2/3 e 3 carcinomas em mulheres com ambos os testes positivos. Conclusão: A prevalência da infecção genital por HPV de alto risco foi alta, seguindo uma curva na qual se observou novo aumento da prevalência após os 55 anos. / The causal role of high risk human papillomavirus (HPV) infection and cervical cancer has been well documented. However HPV prevalence varies greatly across populations, as might the age distribution. Objective: We aimed to determine high risk HPV prevalence and its distribution by age groups. Risk factors, cytological, colposcopic and cervical biopsies results associated with high risk HPV infection in a sample of women who self referred for cervical cancer screening. Methods: In a cross sectional study we interviewed and obtained cervical specimens from a sample of randomized 2300 women (15-65 years). Specimens were tested for the presence of high risk HPV using Hybrid Capture II (HCII) and for cervical cytological abnormalities by Pap smears or liquid based cytology. Women, who had abnormal cytology or positive HCII, or both results, were referred to colposcopy examination. Whenever colposcopy revealed an abnormal pattern, a directed punch biopsy was taken. Results: Four hundred and eight (17.7%) study participants tested positive for high risk HPV types by HC2: 27% (<25 years), 21% (25-34 years), 12% (35-54 years) and 14% (55-65 years). The main risk factor for HPV infection was number of lifetime sexual partners; age at 30 to 54 years, women who live with a partner and former smokers were negative associated with high risk HPV infection. Two hundred four (8, 8%) women had cytological abnormalities. HC II positive was associated with cytology outcome (14, 3% in normal cytology, 78% in HSIL and 100% in cervical cancer). Cervical Intraepithelial Neoplasia grade 2/3 (CIN 2/3) were found in 10 HPV infected women with normal cytological results. Women with abnormal cytological results only had 4 CIN 2/3 and 1 carcinoma and women testing positive in both techniques had 15 CIN 2/3 and 3 carcinomas. Conclusions: High risk HPV prevalence was high in this sample and the prevalence age curve showed a second pick starting around 55 years old.

Câncer cervical é a terceira causa de morte em mulheres no mundo, e a quarta causa de morte em mulheres no Brasil. Seu principal agente etiológico é o vírus do papiloma humano (HPV), e diversos estudos estão sendo feitos na tentativa de desenvolver abordagens terapêuticas que combatam tumores induzidos por HPV. Nesse contexto, surgem às vacinas de DNA, capazes de induzir resposta imune específica contra esse tipo de tumores em camundongos. Entretanto essas vacinas apresentam baixa imunogenicidade em humanos, sendo necessária estudar abordagens que aumentem a potência dessas vacinas. Eletroporação in vivo (EP) é um método de entrega de vacinas de DNA, capaz de elevar potência das mesmas. Nosso grupo desenvolveu uma imunoterapia baseada em DNA (pgDE7h), e quando associamos a EP em nossa imunização pela via intramuscular, observamos aumento do efeito antitumoral e da frequência T CD8+E7-específicas e citotóxicas, migração de células para o sítio de inoculação do DNA, indução de células T polifuncionais e de memória, além de maior avidez de células T ativadas. / Cervical cancer is the third leading cause of death in women worldwide, and the fourth leading cause of death in women in Brazil. Its main etiological agent is human papilloma virus (HPV), and several studies are being done in trying to develop therapeutic approaches that fight tumors induced by HPV. In this context, there are the DNA vaccines are capable of inducing specific immune response against this type of tumors in mice. However, these vaccines have a low immunogenicity in humans, it is required to study approaches to increase the potency of these vaccines. In vivo electroporation (EP) is a method of delivering DNA vaccines, capable of raising power of the same. Our group has developed a DNA-based immunotherapy (pgDE7h), and when associate EP in our immunization by intramuscularly observed increase antitumor effect and frequency CD8+E7-specific and cytotoxic, cell migration for the inoculation site of the DNA polyfunctional T cell induction and memory, and higher avidity for activated T cells.

Le cancer du col de l'utérus est le seul cancer pour lequel nous disposons de 2 outils complémentaires de prévention : la vaccination anti HPV (Human Papillomavirus) et le dépistage par frottis cervico-utérin. Malgré ces outils, ce cancer est responsable de 1000 décès chaque année en France, la plupart survenant chez des femmes avec un suivi non conforme aux recommandations concernant le dépistage. Notre premier article, utilisant les données du registre des cancers gynécologiques de Côte-d'Or, s'est intéressé aux facteurs associés à la mortalité par cancer du col de l'utérus. Il confirme une association significative entre non compliance au dépistage et décès. On retrouve par ailleurs des marqueurs de vulnérabilité socio-économique marqués dans notre population.Notre deuxième article avait pour objectif de déterminer la couverture vaccinale anti-HPV dans notre département ainsi que les facteurs associés à la vaccination. Une étude transversale a été menée entre octobre 2010 et mai 2011 auprès de 948 jeunes filles de 14 ans et plus scolarisées en Côte-d’Or. Pour rappel, les recommandations nationales avant 2012 ciblaient les jeunes filles de 14 ans et celles de 15 à 23 ans pour la vaccination de rattrapage. Les taux d’initiation de la vaccination étaient de 42,1% chez les filles de 14 ans et de 57,3% chez les plus âgées, insuffisants pour obtenir une efficacité optimale de la vaccination. Les freins parentaux rapportés par les jeunes filles étaient complexes. Les jeunes filles avaient une connaissance confuse et parcellaire des infections sexuellement transmissibles en général et des infections à HPV en particulier.Notre troisième article porte sur le dépistage des cancers cervical et colorectal au sein d'une population de femmes résidant en Côte-d'Or et sensibilisées à la question de la prévention des cancers, car compliantes au dépistage du cancer du sein. En France, le dépistage du cancer du col de l'utérus relève d'une initiative individuelle à l'inverse des dépistages du cancer du sein et colorectal qui fonctionnent sur un mode organisé. Au total, 1 856 femmes âgées de 50 à 65 ans ont répondu à un questionnaire envoyé par voie postale. L'objectif était de déterminer le taux de participation aux dépistages du cancer du col de l'utérus et du cancer colorectal ainsi que les facteurs associés. Les taux retrouvés étaient respectivement de 78,3% et 56,6% et cachaient des disparités notamment socio-économiques et de recours au système de soin.A l’issue de ce travail, des questions restent à explorer eu égard à ces deux modes de prévention complémentaires. Le suivi des cohortes de jeunes filles vaccinées permettra à long terme d’évaluer l’impact de la vaccination sur l’incidence des cancers du col de l’utérus, l’épidémiologie des HPV et la protection conférée vis à vis des autres cancers HPV positifs. Il conviendra également de définir les modalités du dépistage de ces jeunes filles en incluant peut être les tests HPV dans leur suivi. / Two complementary prevention tools exist for cervical cancer : HPV vaccination (Human Papillomavirus) and screening using Pap smear. Despite these effective tools, this cancer is responsible for 1,000 deaths each year in France, mostly in women who are not in accordance with the national recommendations regarding screening. Our first article, using data from the registry of gynecological cancers of Côte-d'Or, aimed to identify factors associated with mortality from cervical cancer. A significant association between non adequate follow up by screening and death was found. Association with socio-economic vulnerability and cancers was also noticed.The purpose of our second article was 1) to assess HPV vaccine coverage in a representative population of girls, aged 14 and above, attending school in Côte-d'Or and 2) to identify correlates of vaccines initiation and completion. A cross-sectional study was carried out between October 2010 and May 2011 in 948 girls. Vaccine initiation rates were 42.1% among 14-year-old girls and 57.3% among the oldest, insufficient to achieve optimal vaccination efficacy. Parental concerns about the acceptability of HPV vaccination were found and barriers to vaccination initiation and completion were complex. Girls had poor and confuse knowledge about sexually transmitted diseases in general and HPV in particular. Our third article deals with cervical and colorectal cancers screening in a population of women living in Côte-d'Or and up to date for breast cancer screening. In France, cervical cancer screening is an individual initiative, unlike screenings for breast and colorectal cancers, which are organized at a national level. Overall, 1856 women aged 50 to 65 returned a self-reported questionnaire delivered by post. The objective was to determine participation rates and factors associated with participation in both colorectal and cervical cancer screenings. Respectively 78.3% and 56.6% women were up to date for the two screenings with disparities regarding socioeconomic status and health care facilities access.Additional questions have to be explored on these two complementary modes of prevention. Follow up of cohorts of vaccinated girls will allow assessing the impact of vaccination on the incidence of cervical cancers, HPV epidemiology and the protection afforded against other HPV positive cancers. It is also important to define how vaccinated girls should be screened. HPV tests in this context are promising.

Estudos têm demonstrado que o microambiente tumoral é rico em ATP e adenosina, sugerindo o envolvimento da sinalização purinérgica no desenvolvimento e/ou manutenção do câncer. Ainda, o receptor purinérgico P2X7, conhecido pelo seu papel na indução de apoptose, encontra-se reduzido em alguns tecidos tumorais em comparação aos tecidos saudáveis, indicando que a sua redução possa ser um mecanismo de resistência celular à apoptose. Dessa forma, compreender o papel da sinalização purinérgica no contexto do câncer se torna indispensável e permite que novas abordagens terapêuticas sejam implementadas. Nesse trabalho, avaliamos a função dos nucleotídeos e nucleosídeos da adenina, bem como do receptor P2X7 na indução da morte celular em células de câncer cervical. Também verificamos o efeito do heat shock na potencialização da atividade do receptor P2X7 frente à curta exposição ao ATP em células de câncer de cólon. De acordo com os nossos resultados, o efeito citotóxico do ATP extracelular nas linhagens de câncer cervical é mediado principalmente pela ação do seu metabólito adenosina, que ao entrar no interior das células, promove o aumento dos níveis intracelulares de AMP, ativação de AMPK, aumento da p53 e indução de autofagia. O papel do receptor P2X7 nesse contexto parece ser apenas coadjuvante, visto que o seu bloqueio ou silenciamento impediu em apenas 20% a morte celular. Além disso, utilizando células de câncer de cólon, nós demonstramos que o heat shock aumenta a funcionalidade do receptor P2X7, independente da interação com heat shock proteins ou canais do tipo conexina/panexina, potencializando o efeito citotóxico do ATP. Esse efeito parece estar relacionado à mudanças na composição e arquitetura da membrana celular, visto que o uso do agente fluidizador de membrana benzil álcool foi capaz de mimetizar o efeito do heat shock na potencialização do receptor P2X7 a 37ºC. Este estudo fornece evidências adicionais sobre o papel da sinalização purinérgica no contexto da biologia celular tumoral e abre novas perspectivas para o uso dos nucleotídeos de adenina associados a hipertermia como agentes adjuvantes na terapia do câncer. / The tumor microenvironment is rich in ATP and adenosine, suggesting an involvement for purinergic signaling in cancer development and surveillance. The P2X7 receptor, among the P2 purinergic receptors, is broadly recognized as the “death receptor”, because it promotes cell apoptosis when exposed to high levels of extracellular ATP. Researches have been shown that P2X7 protein levels are decreased at the tumor site in comparison to adjacent healthy tissue, suggesting a mechanism of tumor escape to cell death. Thus, understanding purinergic signaling in a cancer context becomes urgent and opens a new field for therapeutic strategies. Here, we evaluated adenine nucleotides and nucleosides cytotoxicity, as well as P2X7 role in cell death induction using cervical cancer cell lines. Indeed, we investigated heat shock effect on P2X7 functionality through exposing colon cancer cell shortly to ATP at 40ºC. According to our data, adenosine uptake formed from ATP metabolism is the main responsible for the extracellular ATP cytotoxicity in cervical cancer cells. While inside of the cell, adenosine is converted to AMP, leading to AMPK activation, p53 increase and autophagy induction. ATP induced cell death per se through P2X7 in this context seems to be less important, since P2X7 blockage or knocking down reduced only 20% of cell death. In colon cancer cells, we found that heat shock stress was able to increase P2X7 pore formation independently of heat shock protein interaction or native pore-forming transporters association (e.g pannexin-or connexin-type channels), thus leading to an increase ATP cytotoxicity. The mechanism enrolled in this process seems to be related to changes in the lipid composition and architecture of membrane, as the membrane fluidizer benzyl alcohol could reproduce heat stress effect in potentiating P2X7 activation at 37ºC. In conclusion, our work provides further evidence for a purinergic signaling role in the cancer biology context and opens new perspectives for the utility of purine-based drugs associated to hypertermia as adjunctive agents in cancer therapy.

Magister Public Health - MPH / The study aimed to describe the knowledge and awareness of HPV infection and vaccine of female university students and to determine the predictors of vaccine acceptability. The study found that 70% of the participants were sexually active. Awareness and knowledge on HPV/vaccine were poor; with only 22% being aware of HPV and that a HPV vaccine was available in South Africa. A greater proportion (80%) reported willingness to be vaccinated. Being aware of the existence of a pap smear, higher knowledge about HPV, higher perceived vaccine effectiveness and higher perceived severity of HPV infection were significantly associated with increased willingness to be vaccinated. / South Africa

Multi-helix rotating shield brachytherapy (RSBT) applicator and multi-source RSBT apparatus are two novel intensity-modulated brachytherapy techniques for the treatment of cervical and prostate cancer, respectively. The use of imaging techniques such as magnetic resonance imaging guided brachytherapy has enabled the precise identification and contouring of tumor volumes for treatment planning, as well as demonstrated the challenges associated with using conventional high dose rate brachytherapy (HDR-BT) approaches to conform the radiation dose to the target and avoid surrounding sensitive healthy tissues. The target conformity of conventional HDR-BT dose distributions is restricted based on the geometrical constraints imposed by the position and shape of the tube-shaped applicators, as well as the radially-symmetric radiation dose distributions produced by the radiation sources. Dose distribution conformity for cervical and prostate cancer can be significantly improved relative to conventional HDR-BT through the use of multi-helix and multi-source RSBT techniques, respectively. In this study, two novel RSBT concepts for treating cervical and prostate cancer were introduced and the dosimetric impact was evaluated. A Henschke-type cervical cancer applicator, designed for an electronic brachytherapy (eBx) source (Xoft AxxentTM) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles, is proposed. The interior wall of the applicator contains six evenly-spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly-distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. RSBT treatment plans were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. Treatment delivery time and tumor coverage (D90 of HR-CTV) were the two metrics used as the basis for evaluation and comparison. With multi-source RSBT apparatus, precise angular and linear positioning of partially-shielded 153Gd brachytherapy sources in interstitial needles for the treatment of locally-advanced prostate cancer is carried out. Following needle implantation through the patient template, an angular drive mechanism is docked to the patient template. Each needle is coupled to a multisource afterloader catheter by a connector passing through a shaft. The shafts are rotated about their axes by translating a moving template between two stationary templates. Shafts’ surfaces and moving template holes are helically threaded with the same pattern such that translation of the moving template causes simultaneous rotation of the shafts. The catheter angles are simultaneously incremented throughout treatment. For each rotation angle, source depth in each needle is controlled by a multisource afterloader, which is proposed as an array of belt-driven linear actuators, each of which drives a wire that controls catheter depth in a needle. In conclusion, the helical RSBT approach for treating cervical cancer and the multi-catheter RSBT approach for treating prostate cancer, powered with novel radiation sources amenable to shielding, are clinically- and mechanically-feasible techniques that dosimetrically outperform conventional brachytherapy methods while minimizing damage to healthy tissues inside and/or adjacent to the target.

Purpose: To assess rotating shield brachytherapy (RSBT) delivered with the electronic brachytherapy (eBT) source comparing to intracavitary (IC) and intracavitary plus supplemental interstitial brachytherapy (IC+IS BT) delivered with a conventional 192Ir radioactive source. Method and Materials: IC, IC+IS and RSBT treamtent plan were simulated for 5 patients with bulky (>40 cc) cervical cancer. One BT plan for each patient (fraction 1) guided by magnetic resonance imaging (MRI) was used in our treatment planning system (TPS). A bio- and MRI-compatible polycarbonate (Makrolon Rx3158) intrauterine applicator was simulated for IC and RSBT, and the Vienna applicator was simulated for IC+IS BT. 192Ir was used as the radiation source of IC and IC+IS BT, and the Xoft AxxentTM eBT source was used for RSBT. A 0.5 mm thick tungsten shield was used for RSBT with different azimuthal and zenith angles, which reduced radiation transmission through the shield to less than 0.1%. The total dose delivered was calculated as the external beam radiation therapy (EBRT) dose plus the BT dose delivered over five treatment fractions. Results: RSBT and IC+IS BT had higher dose conformity in terms of the minimum dose to the hottest 90% (D90) of the high-risk clinical target volume (HR-CTV) than IC BT for all the patients. The advantage of RSBT over IC+IS BT was dependent on the shield emission angle, tumor shape and tandem applicator location. The delivery time of RSBT was increased as finer emission angle were selected. Conclusions: RSBT is a less-invasive potential alternative to conventional IC and IC+IS BT for treating bulky cervical cancer. RSBT delivery times are clinically acceptable if proper emission angle is selected based on the tumor shape and tandem applicator location.