• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 35
  • 25
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 77
  • 77
  • 77
  • 77
  • 42
  • 31
  • 29
  • 26
  • 26
  • 19
  • 18
  • 16
  • 16
  • 16
  • 15
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Avaliação de fatores de estadiamento em carcinoma epidermoide do esôfago e de fatores imuno-histoquímicos relacionados a apoptose e p53 / Assessment of staging factors in squamous cell carcinoma of the esophagus, and of immunohistochemical factors related to apoptosis and p53

Iberê Cauduro Soares 22 March 2011 (has links)
O carcinoma epidermoide do esôfago continua sendo a principal neoplasia maligna esofágica na população brasileira. Os objetivos desta investigação foram: avaliar a imuno-expressão de um grupo de proteínas relacionadas à via intrínseca da apoptose (bax, APAF-1 e citocromo c) e da proteína p53 em um grupo de carcinomas epidermoides do esôfago; confrontar estes resultados com a atividade proliferativa medida pela imuno-expressão do antígeno Ki67 e com a atividade apoptótica medida pela imuno-expressão da caspase 3 clivada; e confrontá-los com parâmetros implicados no estadiamento do carcinoma epidermoide do esôfago (invasão local ou pT, estado dos linfonodos regionais ou pN, grau de diferenciação do tumor primário e local do tumor primário no esôfago) e com o tamanho do tumor primário. De um grupo inicial de 91 carcinomas esofágicos consecutivos, 66 carcinomas epidermoides do esôfago foram revistos, alocados em micromatrizes teciduais e submetidos à técnica de imuno-peroxidase com anticorpos primários anti: bax, APAF-1, citocromo c, p53, Ki67 e caspase 3 clivada. Suas imuno-expressões foram semiquantificada de 0 a 5+, exceto caspase 3 clivada que foi contada em 1000 células. Apresentaram amostras válidas um conjunto de 63 carcinomas epidermoides do esôfago. A mediana de imuno-expressão destas 6 proteínas foi: 2+, 5+, 5+, 5+, 3+ e 26, respectivamente. Houve correlação positiva entre a imunoexpressão do antígeno Ki67 e a de caspase 3 clivada (coeficiente rho de Spearman =0,373, p=0,003). Houve associação entre a imunoexpressão de APAF-1 e o grau de diferenciação, com valores maiores de APAF-1 para os carcinomas epidermoides do esôfago bem diferenciados (mediana de 5+ para tumores bem diferenciados, contra mediana de 2+ para tumores pouco diferenciados, p<0,001, teste de Kruskal-Wallis). Houve associação entre o tamanho do tumor primário e o nível de invasão local do tumor primário, com tamanhos maiores quanto maior o nível de invasão local dos carcinomas epidermoides do esôfago (mediana de 32,5 mm para os tumores pT1 e mediana de 50,0 mm para os tumores pT3 ou pT4, p=0,027, teste de Kruskal-Wallis). Não houve associação entre as demais variáveis. Embora atividade proliferativa e atividade apoptótica caminhem juntas nos carcinomas epidermoides do esôfago, no estágio invasivo do principal tipo histológico de carcinoma esofágico da população brasileira, não são mais os fatores ligados à via intrínseca da apoptose que influenciam a sua progressão. Além disso, se a imunoexpressão aumentada da proteína APAF-1 estimula a diferenciação nos carcinomas epidermoides esofágicos, não o faz através de estímulo da atividade apoptótica pura e simplesmente / Squamous cell carcinoma of the esophagus remains as the major malignant esophageal neoplasm in the Brazilian population. The objectives of this study were: to assess the immunoexpression of a group of proteins related to the intrinsic pathway of apoptosis (bax, APAF-1 and cytochrome c) and to p53 protein in squamous cell carcinoma of the esophagus; to confront these results with proliferative activity measured by the immunoexpression of Ki67 and with apoptotic activity measured by the immunoexpression of cleaved caspase 3; and to confront them with parameters involved in the staging of squamous cell carcinoma of the esophagus(local invasion or pT, lymph node status or pN, grade of differentiation of primary tumor and site of primary tumor in the esophagus) and with size of primary tumor. From a starting group of 91 consecutive carcinomas of the esophagus, 66 squamous cell carcinomas of the esophagus were selected, revised, placed in tissue microarrays blocks, and submitted to immunoperoxidase technique with primary antibodies to: bax, APAF-1, cytochrome c, p53, Ki67 and cleaved caspase 3. The immunoexpression was semiquantified in a scale from 0 to 5+, except for cleaved caspase 3, whicht was counted in 1000 cells. Sixty three squamous cell carcinomas of the esophagus displayed valid cores for analysis. The median immunoexpression of these 6 proteins were: 2+, 5+, 5+, 5+, 3+ and 26, respectively. A positive correlation was found between Ki67 antigen and cleaved caspase 3 immunoexpression (Spearmans rho coefficient =0.373, p=0.003). There was association between the immunoexpression of APAF-1 and the grade of differentiation, with higher values of APAF-1 for well differentiated squamous cell carcinomas of the esophagus (median of 5+ for well differentiated tumors and median of 2+ for poorly differentiated tumors, p<0.001, Kruskal-Wallis test). The size of primary tumor was statistically associated to the degree of local invasion of primary tumor, with higher size associated to deeper local invasion (median of 32.5 mm for pT1 tumors and median of 50.0 mm for pT3 or pT4 tumors, p=0.027, Kruskal-Wallis test). There was no association among the other variables. Although proliferative activity and apoptotic activity go together in squamous cell carcinomas of the esophagus, the factors involved in the intrinsic pathway of apoptosis does not differ significantly according to the histological parameters in the invasive phase of the development of squamous cell carcinoma of esophagus. Moreover, , if increased immunoexpression of APAF-1 stimulates differentiation of squamous cell carcinomas of the esophagus, it does not work through direct higher apoptotic activity
42

Gelatinases, their tissue inhibitors and p53 in lymphomas

Kyllönen, H. (Heli) 26 May 2009 (has links)
Abstract Lymphomas are a heterogeneous group of malignancies, which usually have a good prognosis and high cure rates. Lymphomas are sensitive to chemotherapy and radiotherapy, and many patients can be cured even after a relapse, resulting in a need for effective follow-up. However, the cost-benefit ratio of radiological imaging in predicting the forthcoming relapses is poor. Consequently, there is a need for biological prognostic and predictive markers to distinguish patients at the highest risk of relapse at the time of diagnosis or during follow-up. Despite rapid progress in lymphoma treatments, some patients still die from lymphoma. Thus, more data on the basic biological features of lymphomas are also needed. Gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) have been found to play a role in the progression of solid tumours. TP53 is a tumour suppressor gene, the mutations and protein over-expression of which have been demonstrated to be associated with survival in most cancer types. There is also some evidence that these proteins could have prognostic significance in lymphomas as well. In the present study, the tissue expression, plasma concentrations and clinical value of gelatinases and their tissue inhibitors were evaluated in lymphomas. 249 primary tissue samples from patients with Hodgkin, follicular, or diffuse large B-cell lymphoma were analysed for expression of gelatinases and/or their inhibitors using immunohistochemistry. In follicular lymphoma, p53 protein expression was also investigated. The plasma samples of 126 lymphoma patients and a control group of 44 healthy volunteers were collected and studied by ELISA. TIMP-1 expression correlated with bulky tumour and nodular sclerosis subtype of Hodgkin lymphoma. In follicular lymphoma, p53 over-expression was an independent adverse prognostic factor for survival and a predictor of histological transformation. Plasma MMP-2-TIMP-2 complex appeared to be a potential follow-up marker predicting the risk of relapse in lymphoma patients. Plasma levels of the MMP-2-TIMP-2 complex, proMMP-2, TIMP-2 and proMMP-2/TIMP-2 ratio were at abnormal levels both in patients with newly diagnosed lymphoma and those in remission compared to healthy controls. The clinical significance of these markers needs further studies.
43

Mdm2 and Mdm4 Functions in Growth Control: a Dissertation

Steinman, Heather Anne 01 June 2004 (has links)
Amplification and/or overexpression of the Mdm2 oncogene occurs in many human cancers. Mdm2 promotes cellular proliferation, interferes with apoptosis, and induces tumor formation through the negative regulation of the p53 tumor suppressor. More than thirty percent of human tumors overexpressing Mdm2 also present with alternatively spliced Mdm2 isoforms that cannot directly bind p53. The presence of Mdm2 isoforms in tumors correlates with a higher tumor grade and a poorer prognosis for the patient. To investigate the function of Mdm2 isoforms in tumorigenesis, we have isolated a number of Mdm2 splice forms from tumors obtained from Mdm2-transgenic mice and find that the most frequently observed splice form in human tumors, Mdm2-b, is conserved in mice. Although the Mdm2-b protein is incapable of binding to p53 and is unable to localize to the nucleus, we demonstrate that Mdm2-b promotes cell growth in NIH3T3 cells, Rb-deficient, p19-deficient, and p53-deficient primary cells. We also show that Mdm2-b inhibits apoptosis in response to serum withdrawal and restimulation, doxorubicin treatment, and TNF-alpha administration. Mdm2-b induces foci formation in vitro and directly contributes to tumor formation in GFAP-Mdm2 transgenic mice. We propose that Mdm2-b promotes tumor growth by upregulating RelA (P65) protein levels and activity in a p53-independent manner. To better understand additional functions of Mdm2 that are p53-dependent, we have generated an Mdm2 conditional mouse model. Using primary mouse embryonic fibroblasts derived from Mdm2 conditional mice, we demonstrate that p21 is required for p53-dependent apoptosis initiated by Mdm2 loss. In support of this observation, we also note that p21-loss partially rescues embryonic lethality of Mdm2 null mice. We further show that p21-loss partially rescues the embryonic lethality caused by the loss of the Mdm2 family member, Mdm4. We address the possibility that Mdm2 and Mdm4 may play redundant roles during embryonic development and find that Mdm2 overexpression fully rescues the embryonic lethality resulting from Mdm4 loss. Our findings demonstrate that both Mdm2 and Mdm4 play critical roles in modulation of the p53 tumor suppressor pathway and that their deregulation can result in tumor formation through both p53-dependent and independent pathways.
44

Insulin-like growth factor-1 (IGF-1) impacts p53-regulated gene products in UVB-irradiated human keratinocytes and skin epidermis

Alkawar, Abdulrhaman Mohammed Mohammed 21 May 2020 (has links)
No description available.
45

Synthesis and quantitative structure-activity relationship of imidazotetrazine prodrugs with activity independent of O6-methylguanine-DNA-methyltransferase, DNA mismatch repair, and p53

Pletsas, Dimitrios, Garelnabi, Elrashied A.E., Li, Li, Phillips, Roger M., Wheelhouse, Richard T. January 2013 (has links)
Yes / The antitumor prodrug temozolomide is compromised by its dependence for activity on DNA mismatch repair (MMR) and the repair of the chemosensitive DNA lesion, O6-methylguanine (O6-MeG), by O6-methylguanine-DNA-methyltransferase (E.C. 2.1.1.63, MGMT). Tumor response is also dependent on wild-type p53. Novel 3-(2-anilinoethyl)-substituted imidazotetrazines are reported that have activity independent of MGMT, MMR, and p53. This is achieved through a switch of mechanism so that bioactivity derives from imidazotetrazine-generated arylaziridinium ions that principally modify guanine-N7 sites on DNA. Mono- and bifunctional analogues are reported, and a quantitative structure-activity relationship (QSAR) study identified the p-tolyl-substituted bifunctional congener as optimized for potency, MGMT-independence, and MMR-independence. NCI60 data show the tumor cell response is distinct from other imidazotetrazines and DNA-guanine-N7 active agents such as nitrogen mustards and cisplatin. The new imidazotetrazine compounds are promising agents for further development, and their improved in vitro activity validates the principles on which they were designed.
46

Uso da solução de Lugol para a detecção de segundos tumores primários de boca e orofaringe em portadores de carcinoma epidermóide na cabeça e pescoço: correlação dos achados na histopatologia com a imunoexpressão do p53 e metalotioneína / Using the Lugols solution for detection of seconds primary tumors of oral and oropharyngeal in patients with head and neck squamous cell carcinoma: correlation of histopathology findings with immunohistochemical p53 expression and metallothionein.

Simões, Cesar Augusto 27 May 2009 (has links)
O diagnóstico precoce dos Segundos Tumores Primários (STP) em pacientes já tratados por um carcinoma de cabeça e pescoço deve ser realizado, pois possibilita um tratamento resolutivo com baixa morbidade. O objetivo deste trabalho é avaliar se a cromoscopia com Lugol permite uma melhora na identificação de lesões malignas ou pré malignas em fases iniciais na boca e orofaringe, bem como se a imunoexpressão do p53 e da Metalotioneína no tumor índice predizem o aparecimento de um STP. Foi realizado um estudo prospectivo onde dois grupos comparáveis de portadores de carcinoma epidermóide de cabeça e pescoço foram formados (um com 106 pacientes e outro com 105 pacientes). Foram acompanhados durante um período médio de 25 meses aproximadamente. No primeiro grupo (grupo A) não foram utilizados corantes, já no segundo (grupo B) utilizou-se o Lugol. Foi observado um número de diagnósticos 200% maior no grupo em que foi utilizada a coloração de Lugol (grupo B) em relação ao grupo A. A imunoexpressão aumentada do p53 no tumor índice foi estatisticamente significante quando o paciente desenvolveu um segundo tumor primário diagnosticado pelo Lugol, não visível sem o corante, o que não ocorreu com a metalotioneína. / The early diagnosis of seconds primary tumors (STP) in patients already treated for carcinoma of the head and neck should be done, because enables a resolutive treatment with low morbidity. The objective of this paper is to evaluate whether chromoscopia using Lugols solution allows an improvement in the identification of malignant or pre malignant lesions in early stages in the mouth and oropharynx, and whether the expression of P53 and metallothionein in tumor index predict the emergence of a STP. A prospective study was conducted, where two groups statistically similar of patients with head and neck squamous cell carcinoma (one with 106 patients and another with 105 patients) were followed-up for a median period of 25 months, approximately. In the first group dyes were not used, and in the second Lugols solution was employed. It was observed a number of diagnoses 100%i higher in the group that Lugols solution was used. The increasing of P53 expression in tumor index was statistically significant when the patient developed a second primary tumor diagnosed by Lugol, not visible without dye, which has not occurred with metallothionein.
47

Tumores gástricos primários múltiplos e únicos: análise imunohistoquímica comparativa / Multiple and solitary primary gastric tumors: comparative immunohistochemistry analysis

Jorge, Uana Maria Miguel 06 December 2006 (has links)
Introdução: Adenocarcinomas gástricos múltiplos primários (AGMP) são encontrados em 3,5% a 10% de todos os pacientes com câncer gástrico. A multiplicidade tumoral é amplamente reconhecida como indicador de predisposição genética para o desenvolvimento de neoplasias Além disso, as rotas de carcinogênese não estão claramente definidas nestes tumores (rota mutadora, ou supressora, ou da E-caderina). Objetivo: avaliar a imunoexpressão de hMLH1, hMSH2, e hMSH6 (rota mutadora), p53 (rota supressora) e E-caderina nos AGMP comparando-se com adenocarcinomas únicos (pareados quanto ao sexo, idade, tipo histológico, localização e estádio) e sua relação com dados clínico-patológicos. Casuística: dezenove pacientes com AGMP foram comparados a 21 pacientes com tumores gástricos únicos quanto a características imunohistoquímicas. Métodos: Blocos de tecido fixados em formalina a 10% e incluídos em parafina foram submetidos a cortes histológicos de 4 mm, para as avaliações histológica e imunohistoquímica para hMLH1, hMSH2, hMSH6, p53 e E-caderina. Resultados: A média de idade dos pacientes com AGPM foi de 66 + 9,06 anos, e de 60 + 16,9 anos nos pacientes com tumor único (P=0,56). Vinte e dois tumores estavam localizados na porção distal do estômago; 14, no corpo e cinco na porção proximal. Em 14 pacientes, as lesões eram próximas (< 3 cm), enquanto que, em cinco pacientes, as lesões estavam em outra porção do estômago. O estágio final anatomopatológico pós-operatório foi: 15 no estágio T1 (37,5%) (8 múltiplos e 7 únicos), 7 no estágio T2 (17,5%) (1 múltiplo e 6 únicos), 17 no estágio T3 (42,5%) (9 múltiplos e 8 únicos) e 1 no estágio T4 (27,5%) (1 múltiplo). Segundo a classificação de Laurén, 45 dos tumores foram do tipo intestinal (29 múltiplos e 16 únicos), 16 do tipo gástrico (12 múltiplos e 4 únicos) e um tumor do tipo misto (1 único). O estádio anatomopatológico revelou 30 tumores avançados (16 múltiplos e 14 únicos) e 32 precoces (25 múltiplos e 7 únicos). Na imunohistoquímica, não houve diferença entre a imunoexpressão nos dois grupos de tumores quanto a: hMLH1 (24,3% vs. 19% P=0,64), hMSH6 (4,8% vs. 2,4%, P=0,68), p53 (39% vs. 24%, P=0,35) e E-caderina (27% vs. 19%, P=0,46). hMSH2 foi positivo em todos os casos. Não houve associação entre os imuno-marcadores e os dados clínico-patológicos. Conclusões: 1. As rotas de carcinogênese, mutatora, supressora e E-caderina parecem estar independentemente envolvidas no desenvolvimento dos AGMP; 2. Não houve diferença de imunoexpressão dos marcadores analisados quando compararam-se os AGMP e os tumores únicos. / Introduction: Multiple primary gastric adenocarcinomas (MPGA) have been reported from 3.5% to 10% of all patients with gastric cancer. Tumoral multiplicity is largely known as an indicator of genetic predisposition for the development of neoplasias. Moreover, the route of carcinogenesis has not been clearly clarified in these tumors (mutator pathway or suppressor pathway). Aim: to evaluate the immunoexpression of hMLH1, hMSH2, and hMSH6 (mutator pathway), p53 (suppressor pathway) and E-cadherin in the MPGA, comparing to solitary adenocarcinomas (similar gender, age, histological type, location and staging) and also the relation to the clinicopathological data.: Casuistics: Nineteen patients (Group 1) with MPGA were compared to 21 patients (Group 2) with solitary gastric tumors regarding clinicopathological characteristics and immunohistochemistry. Methods: Blocks of tissue fixed in 10% formalin and embedded in parafin were submitted to 4 mm sections for histological and immunohistochemistry analysis for hMLH1, hMSH2 and hMSH6 (mutator pathway), p53 (suppressor pathway) and E-cadherin. Results: The mean age for the MPGA was 66.8 + 9.06 years, and 59.0 + 16.9 years for the solitary tumor group(P = 0.27). Twenty-two tumors were in the distal stomach, 14 were in the body and five in the proximal portion. In 14 patients the lesions were close to each other (< 3 cm), while in five patients the neoplasias were distant, in another portion of the stomach.The final postoperative pathological stage was: T1 in 15 (eight multiple and seven solitary), T2 in seven (one multiple and six soliatry), T3 in 17 ( nine multiple and eight solitary) and T4 in one ( one multiple). According to the Laurén classification, 45 tumors were intestinal type (29 multiple and 16 solitary), 16 were diffuse (12 multiple and four solitart) and one mixed type ( one solitary). 30 tumors were diagnosed in advanced staging (16 multiple and 14 soliatry) and 32 were early (25 multiple and seven solitary). There was no difference between the hMLH1 immunoexpression in the two groups (24.3% vs. 19%, P=0.64), hMSH6 (4.8% vs. 2.4%, P=0.68), p53 (39% vs. 24%, P=0.35) and E-cadherin (27% v.s 19%, P=0.46). Immunostaining for hMSH2 was positive in all MPGA, indicating absence of alterations of this repair gene marker. There was no association between the immunomarkers and the clinicopathological data. Conclusions: 1. Routes of carcinogenesis, mutator, suppressor, and E-cadherin appear to be involved independently in the development of MPGA; 2. There was no difference in the markers immunoexpression in the two groups.
48

Terapia gênica do câncer associando reparo da via p53 à imunoestimulação por IFNbeta / Cancer gene therapy associated repair via p53 immunostimulation by IFNbeta

Catani, João Paulo Portela 11 September 2014 (has links)
Os avanços científicos das últimas décadas permitiram que a compreensão do câncer evoluísse de uma visão simplista, na qual o principal motor seria uma atividade celular hiperploriferativa, para uma visão mais complexa onde o estado fisiológico geral permite a gênese e progressão tumoral. Essa evolução permite o desenvolvimento de novas abordagens terapêuticas e traz novas esperanças para o tratamento de muitos tipos de cânceres ainda extremamente deletérios. Dentro desse novo panorama, terapias que estimulem a imunidade antitumoral têm se mostrado extremamente promissoras. Nesse trabalho, procuramos investigar os efeitos antitumorais desencadeados pela combinação da indução de morte celular e imunoestimulação. Para tanto, visamos à recuperação da via de p53 (pela transferência gênica do próprio p53 ou p19) associada à transferência gênica de IFNbeta. A transferência gênica foi mediada por vetores adenovirais do sorotipo 5. Nossas observações, em um modelo murino de carcinoma pulmonar, permitem concluir que esta linhagem é sensível a morte induzida pela transferência gênica de p19 e não p53. Porém, a transferência gênica intratumoral de IFNbeta se mostrou chave no controle do crescimento do tumor primário. Destacamos, entretanto, que a associação de IFNbeta com p19 produziu efeitos imunoprotetores superiores à transferência de IFNbeta ou p19 sozinhos. Tal efeito parece ser dependente da indução de fatores quimiotáxicos e conseqüente recrutamento de neutrófilos para o sítio tumoral. O efeito da transferência gênica combinada de ambos os genes IFNbeta e p19 se mostrou ainda mais promissor quando associado à cisplatina, induzindo uma notável redução no crescimento tumoral / Scientific advances from the last decades enabled the evolution of our knowledge of cancer from a simplistic vision, in which the main motor was an excessive cell proliferation, to a more complex one, where the general physiologic state enables tumorigenesis and tumor progression. This evolution enabled the development of new therapies and brings new hopes for the treatment of several types of cancers. In this context, therapies that induce an antitumor immunity are very promising. In this work, we are investigating the antitumor effects triggered by the combination of cell death induction and immunostimulation. To this end, we aimed to restore p53 pathway (by p53 or p19 gene transfer) associated with immunostimulation by IFNbeta gene transfer. The gene transfer was mediated by Adenovectors Serotype 5. Our observations in a murine model of lung cancer showed that this cell line is sensitive to cell death induced by p19 gene transfer, but not p53. Nevertheless, intratumoral gene transfer of IFNbeta, was crucial in controlling tumor growth. Moreover, p19 and IFNbeta association induced higher immunoprotecting effects than p19 or IFNbeta alone. This effect seems to be depending on the induction of chemotactic factors, and the recruitment of neutrophils to the tumor site. The effect of combined gene transfer of p19 and IFNbeta was even more promising when associated with Cisplatine, inducing a remarkable reduction in tumor growth
49

Leucoplasia oral: tratamento cirúrgico com laser de CO2 e de diodo e análise por imuno-histoquímica da expressão de proteínas relacionadas à carcinogênese (p53, COX-2 e EGFR) / Oral leukoplakia: surgical treatment with CO2 and diode lasers and analysis of the expression of proteins related to carcinogenesis (p53, COX-2 e EGFR) by immunohistochemistry

Kern, Vivian Cunha Galletta 03 March 2010 (has links)
Leucoplasia oral (LO) é uma lesão potencialmente maligna, definida como uma placa branca que não pode ser caracterizada como outra doença da mucosa oral. Dentro de certo consenso, as LOs devem ser tratadas, mas nenhum tratamento disponível tem a capacidade de prevenir a transformação maligna. Este trabalho teve como objetivo avaliar a eficácia do tratamento cirúrgico das LOs por lasers de CO2 e diodo e verificar a ocorrência de desfechos clínicos de recidivas, desenvolvimento de novas lesões ou transformação maligna após o tratamento. Adicionalmente foi realizado estudo imunohistoquímico em material biopsiado das lesões e em tecido normal gengival (grupo controle). Fatores reconhecidamente de risco como hábitos nocivos (álcool e tabagismo), características clínicas das lesões, grau de displasia, bem como a expressão dos anticorpos investigados, foram analisados e relacionados com a ocorrência de desfechos clínicos em 40 pacientes atendidos no ambulatório de Estomatologia Clínica. Os cortes histológicos das lesões foram classificados de acordo com o grau de displasia e com um sistema binário, e subsequentemente foram testados para os anticorpos anti-p53, anti-COX-2 e anti- EGFR através de reação imuno-histoquímica. Análise de Kaplan-Meier, seguida do teste de log-rank e análise de regressão de Cox avaliaram a ocorrência de recorrência, desenvolvimento de novas lesões e transformação maligna e possíveis fatores relacionados com esses desfechos clínicos. Teste de odds ratio e de x2 avaliaram a expressão dos anticorpos investigados em LOs e grupo controle. Pacientes com LO apresentaram idade média de 60,5 anos e a relação homem/mulher foi de 1,35:1. Hábitos de tabagismo e etilismo foram prevalentes em homens. A maior parte das lesões era < 2 cm (57,1%), tinha aspecto homogêneo (67,3%) e displasia epitelial (61,2%); apenas 7 lesões eram de alto risco (sistema binário). Desfechos clínicos de recorrência, desenvolvimento de novas lesões ou transformação maligna foram observados em 37,5% dos pacientes; 2 pacientes desenvolveram malignidade em sítios distintos da LO inicial. Análise estatística mostrou associação entre desfecho de recorrência e lesões de alto risco, e entre desfecho de desenvolvimento de novas lesões e mulheres acima de 60 anos. Os anticorpos p53 e COX-2 foram mais expressos em LOs que no grupo controle, mas a expressão de nenhum anticorpo foi relacionada com os desfechos clínicos avaliados. O tratamento por lasers de alta potência (CO2 e diodo) mostrou-se eficiente na remoção das lesões, embora não tenha evitado desfechos clínicos de recorrência, desenvolvimento de novas lesões e transformação maligna. Lesões de alto risco e mulheres acima de 60 anos constituíram fatores de risco aos desfechos clínicos, enquanto os anticorpos analisados não foram eficientes para prognosticar a evolução das LOs. / Oral leukoplakia (OL) is a potentially malignant lesion, defined as a white patch that cannot be characterized as any other disease of the oral mucosa. In general, OL should be treated; however no treatment available has been able to prevent malignant transformation. The aim of this study was to evaluate the efficacy of surgical treatment with CO2 and diode lasers in 40 patients with OL and the occurrence of clinical outcomes of recurrence, development of new lesions or malignant transformation, after treatment. Additionally, an immunohistochemistry study was performed in OL biopsy-specimen and in gingival normal tissue (control group). Recognized risk factors such as habits (alcohol and tobacco), clinical characteristics of lesions, grade of dysplasia, as well as the expression of immunohistochemistry reaction were analyzed. Histological slides of lesions were classified according to the grade of dysplasia and a binary system, and subsequently tested for the anti-p53, anti-COX-2 and anti-EGFR antibodies by immunohistochemistry assay. Kaplan-Meier analysis along with log-rank test and Cox regression analysis were used to assess the occurrence of clinical outcomes and the association with risk factors. Odds ratio and x2 tests evaluated the expression of the investigated antibodies in OLs and in the control group. Patients with OL had a mean age of 60.5 years and the men/women ratio was of 1.35:1. Smoking and alcohol habits were more prevalent among men than in women. Lesions were clinically characterized as measuring less than 2 cm (57.1%), with a homogenous aspect (67.3%) and histologically with epithelial dysplasia (61.2%); only 7 lesions were classified as of high-risk (binary system). Clinical outcomes (recurrence, development of new lesions and malignant transformation) were observed in 37.5% patients; 2 patients developed malignancy in areas distant from the initial OL site. Statistical analysis showed association between recurrence and high-risk lesions, and between development of new lesions and women over 60 years old. Anti-P53 and anti-COX-2 antibodies were more expressed among OL than in the control group, but no antibody expression was related to the clinical outcomes analyzed. Surgical treatment with high-power lasers (CO2 and diode) showed to be efficient in the removal of OL lesions, but it did not avoid clinical outcomes of recurrence, development of new lesions and malignant transformation. High-risk lesions and women over 60 years old constituted risk factors for the clinical outcomes, while the analized antibodies were not usefull markers to characterize OL lesions with higher risk of malignancy.
50

Avaliação na linhagem endotelial tEnd dos efeitos diretos da transferência gênica de IFNbeta e p19arf e efeitos parácrinos mediados pela linhagem B16 transduzida pelos mesmos vetores adenovirais / Distinct roles of direct transduction versus exposure to the tumor secretome on murine endothelial cells after melanoma gene therapy with interferon-? and p19Arf

Vieira, Igor de Luna 18 March 2016 (has links)
A vascularização tem um papel central na progressão tumoral e representa um alvo terapêutico de grande interesse. A inibição da angiogênese tem potencial de retardar a progressão tumoral e inibir metástase. Em decorrência disto, terapias anti-angiogênicas têm demonstrado ser promissora no controle do crescimento tumoral. Segundo a literatura, interferon-? (IFN?, ativador do sistema imune inato e adaptativo) e p19Arf (supressor de tumor e parceiro funcional de p53), quando estudados individualmente, alteram a vasculatura tumoral. Nosso grupo construiu e utilizou vetores adenovirais recombinantes portadores dos cDNAs de INFbeta e p19Arf e observou que a transferência desta combinação de genes induziu morte celular e diminuiu progressão tumoral, resultados foram observados em modelos murinos de melanoma B16 de terapia genica in situ, vacina profilática e vacina terapêutica. Neste trabalho, exploramos a ideia que a combinação dos vetores adenovirais portadores de INFbeta e p19Arf proporcionam efeitos anti-angiogênicos através de seu impacto em células endoteliais. Para averiguarmos essa hipótese, células endoteliais murinas (tEnd) foram transduzidas com os vetores adenovirais, revelando que o vetor Ad-p19 confere inibição da proliferação, formação de tubos, migração e induz aumento na expressão de genes relacionados a via de p53 e morte celular. O vetor Ad-IFNbeta sozinho ou adicionado em combinação com Ad-p19, não teve impacto significante nestes ensaios. Alternativamente, a influencia indireta, ou parácrina, nas células tEnd cultivadas juntamente com as células B16 transduzidas com os vetores adenovirais também foi investigada. Quando as células B16 foram transduzidas com Ad-IFNbeta ou a co-transdução Ad-IFNbeta+Ad-p19 em co-cultura com a linhagem tEnd, houve inibição da proliferação. Não observamos efeito inibitório na tEnd da co-cultura quando as células da B16 foram transduzidas somente com Ad-p19. Seguindo o ensaio de co-cultura, produzimos meio condicionado da B16 transduzida com os vetores e aplicamos esses meios nas células tEnd. Observamos que Ad-IFN, sozinho ou em combinação com Ad-19, diminuiu a viabilidade, proliferação e levou a morte das células tEnd. Neste trabalho, constamos que inibição de células endoteliais pode ser realizada por transdução direta com Ad-19 ou quando estas células são expostas ao ambiente modulado por células tumorais transduzidas com o vetor Ad-IFNbeta. Mesmo que a transferência gênica de ambos IFNbeta e p19Arf não demonstrou ser uma abordagem superior à aplicação dos genes isolados, observamos que nossa abordagem pode ter um impacto importante na inibição da angiogênese pelas células endoteliais / The vasculature plays a central role in tumor progression and represents a therapeutic target of great interest. Inhibition of angiogenesis has the potential to slow down tumor progression and inhibit metastasis. As a result, anti-angiogenic therapies have been shown to be promising for the control of tumor growth. According to the literature, interferon ? (IFN?, activator of the innate and adaptive immune systems) and p19Arf (tumor suppressor and functional partner of p53) when studied individually alter tumor vasculature. Our group has constructed and used recombinant adenovirus vectors carrying the cDNAs of INFbeta and p19Arf and noted that the transfer of this combination of genes induced cell death and decreased tumor progression, as observed in the B16 murine model of in situ melanoma gene therapy as well as prophylactic and therapeutic vaccine approaches. In this study, we explore the idea that the combination of adenoviral vectors bearing INFbeta and p19Arf produce anti-angiogenic effects due to their impact on endothelial cells. To test this hypothesis, murine endothelial cells (tEnd) were transduced with adenoviral vectors, revealing that Ad-p19 vector confers inhibition of proliferation, tube formation, migration and induces increased expression of genes related to the p53 cell death pathway. The Ad-IFNbeta vector alone had no significant impact on these tests. Alternatively, influences on paracrine effects are evaluated on endothelial cells co-cultured with B16 cells that were previously transduced with adenoviral vectors. When the B16 cells were transduced with Ad-IFNbeta or co-transduced with Ad-IFNbeta + Ad-p19, co-culture resulted in the inhibition of proliferation of the endothelial cells. When B16 cells were transduced with Ad-p19 only, co-culture did alter endothelial cell behavior. Following the co-culture assay, we produce conditioned medium from B16 cells that were transduced with the vectors and applied the media on tEnd cells. We noted that conditioned medium derived from B16 transduced with Ad-IFN alone or in combination with Ad-19 decreased the viability and proliferation and induced cell death of tEnd. In this work, we show that inhibition of endothelial cells can be performed directly by transduction with Ad-19 or when such cells are exposed to the environment modulated by tumor cells transduced with Ad-IFNbeta. Even though the gene transfer of both IFNbeta and p19 was not found to be superior to the application of single genes, we observed that our approach may have an important impact on the inhibition of angiogenesis through endothelial cells

Page generated in 0.1153 seconds