Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-21T20:57:06Z No. of bitstreams: 1 VicenilmaMartins.pdf: 7618309 bytes, checksum: 3d94fb00454be15b5872822df938424e (MD5) / Made available in DSpace on 2017-08-21T20:57:06Z (GMT). No. of bitstreams: 1 VicenilmaMartins.pdf: 7618309 bytes, checksum: 3d94fb00454be15b5872822df938424e (MD5) Previous issue date: 2017-04-28 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / Infection by HPV is described in the literature in 30-50% of cases of penile cancer. The immunohistochemical of p16INK4a is used as an indication of the presence of HPV and prognostic marker for squamous carcinomas various sites. However, its role in penile carcinoma has not yet been completely elucidated. The aim of the study was to prospectively analyze whether the expression of p16INK4a is associated with the presence of HPV and histological parameters in penile cancer. A prospective study was conducted in the period 2014 to 2016 with 55 cases of patients with penile carcinoma. HPV DNA was detected by PCR in fresh tumor tissue and immunohistochemistry for analysis of p16INK4a protein in paraffin waxed tissue. The evaluation of histological parameters was performed after total inclusion of the tumor tissue. HPV DNA (lowrisk and high-risk genotypes) was found in 49 (89.1%) cases, 46 (83.6%) HR-HPV. Of the 22 p16INK4a positive cases, HR-HPV DNA was present in 21 (95.5%) of them (p = 0.032). Regarding histological parameters, p16INK4a and HR-HPV were significantly associated only with the tumor subtype (p = 0.036 and p = 0.032, respectively), being that, all carcinomas with basaloid characteristics were positive p16INK4a. Using a fresh tissue sample, our sample showed the highest incidence of HPV in the literature. Expression of the p16INK4a protein was significantly associated with the presence of high oncogenic HPV virus and may serve as a marker for the presence of this virus. The p16INK4a protein was not associated with the histological prognostic parameters, except for the tumor subtype. / A infecção pelo HPV é descrita na literatura em 30-50% dos casos de câncer de pênis. A expressão imunohistoquímica de p16INK4a é utilizada como indicativo da presença de HPV e marcador prognostico para carcinomas escamosos de vários sítios. No entanto, seu papel no carcinoma de pênis ainda não está totalmente elucidado. O objetivo do estudo foi analisar, de forma prospectiva, se a expressão de p16INK4a está associada a presença de HPV e parâmetros histológicos no câncer de pênis. Estudo prospectivo realizado no período de 2014 a 2016 com 55 casos de pacientes com carcinoma pênis. Foi realizada a detecção do DNA HPV por PCR em tecido tumoral a fresco e a imunohistoquímica para análise da proteína p16INK4a em tecido parafinado. A avaliação de parâmetros histológicos foi realizada após inclusão total do tecido tumoral. O DNA HPV (genótipos de baixo risco e alto risco) foi encontrado em 49 (89,1%) casos, sendo 46 (83,6%) HRHPV. Dos 22 casos p16INK4a positivo, o DNA HR-HPV esteve presente em 21 (95,5%) deles (p = 0,032). Em relação a parâmetros histológicos, a p16INK4a e o HR-HPV foram significativamente associados apenas ao subtipo do tumor (p = 0,036 e p=0,032, respectivamente), sendo que todos os carcinomas com características basalóides foram p16INK4a positivo. Utilizando amostra de tecido a fresco, a nossa casuística mostrou a mais alta incidência de HPV da literatura. A expressão da proteína p16INK4a foi significativamente associada à presença do vírus HPV de alto risco oncogênico e pode servir como marcador da presença desse vírus. A proteína p16INK4a não foi associada aos parâmetros prognósticos histológicos, exceto ao subtipo do tumor.

Xu, Dandan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 209-231). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

No description available.

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown aetiology. Both genetic and environmental factors are known to contribute to disease development. Pathogenesis involves the production of autoantibodies, and the formation of immune complexes, leading to inflammation and destruction of autologous tissue. SLE is a heterogeneous disease both longitudinally and between affected individuals, and is characterised by periods of exacerbation, known as flares, and periods of remission. The ubiquitous human herpes viruses, cytomegalovirus (HCMV), and Epstein-Barr virus (EBV) have been associated with disease by a variety of mechanisms. Data compiled here suggests SLE patients have elevated IgG responses to HCMV and EBV, but unlike healthy controls these responses do not accumulate with age. No association has been found between the carriage of these viruses, or the magnitude of response against these viruses, and any clinical measurements of disease activity. EBV load is 5.4 times higher in SLE patients than controls. Azathioprine treatment is associated with a 4.4 fold rise in EBV load, no other drugs show associations with EBV load. Among SLE patients EBV load is inversely correlated with CD8+ T-cell IFN\(\gamma\) responses, suggesting impaired T-cell responses are the cause of elevated load. HCMV seropositivity is associated with a 7-year delay in development of disease among SLE patients, and a reduction in plasma IFN\(\alpha\) concentration.

γδ T cells play a central role in the detection of epithelial stress as a component of the lymphoid stress surveillance response. Despite their implication in a range of conditions, including several cancers, little is known about how they interact with their antigenic targets, particularly the interaction of γδ TCRs with their ligands. In this thesis I used molecular and structural modelling techniques to characterise recognition of an epithelial stress ligand, EphA2, by a Vδ1+ γδ T cell, MAU. This resulted in a tripartite model of recognition, involving coordinated interaction of EphA2 with both the TCR and its cognate A-ephrin ligands on the T cell, and the identification of a surface patch on the ligand binding domain of EphA2 that potentially represents a TCR binding site. I also performed sequence-level TCR repertoire analysis to assess γδ T cell populations in human colon and liver, and explored, the effect of chronic cytomegalovirus infection on the Vδ1+ γδ T cell repertoire, the first such analysis of its kind. These studies suggested the Vδ2negative repertoire in humans is diverse and largely private, but also highlighted a Vγ5Vδ1 population that was selectively detected in cytomegalovirus-seropositive individuals, and may be involved in cytomegalovirus immunity.

Glioblastoma is a highly malignant and aggressive high grade glioma with a poor prognosis. The low survival rates stem from tumour progression, late intervention, ineffective therapies and drug resistance, requiring new therapeutic and diagnostic approaches. Lipid droplets are dynamic organelles suggested to be influential facets of cancer metabolism and biology in many tumours. In glioblastoma lipid droplets have been associated with hypoxia higher clinical grades and poor survival however the cellular pathways underlying lipid droplet metabolism remain unclear. Using a publically available database of grade 2 ta 4 glioma gene expression, we observed that genes associated with lipid droplet metabolism were important prognostic survival and tumour progression indicators. Moreover, through confocal microscopy, flow cytometry and NMR-based methods, we observed that uptake of exogenous lipids and adipose triglyceride lipase-mediated lipid shuttling produced lipid droplets whilst autophagy was vital to lipid droplet breakdown. ATGL-mediated lipid shuttling was further observed to prevent unsaturated fatty acid oxidative damage. Finally, we investigated the effect of pharmacological lipid droplet manipulation and observed that autophagy inhibition can improve temozolomide and irradiation cytotoxicity. Taken together our data suggests that understanding lipid droplet metabolic pathways may generate prognostic bio-markers of survival and progression and improve current therapies.

Nuclear magnetic resonance spectroscopy (NMR) resonances from lipids and metabolites in tumours are associated with tumour grade and treatment response. The origin of NMR lipid signal is mainly considered to be cytoplasmic lipid droplets (LDs). The aim of this study is to investigate the lipid species of LDs in nervous system tumour cells and identify potential lipidic or metabolic markers in treatment response. NMR spectroscopic analysis revealed that the LDs contain phosphatidylcholine, cholesterol and cholesterol ester with saturated, mono-unsaturated and polyunsaturated fatty acid species. Both saturated and unsaturated lipids are accumulated into LDs in cancer cell death. It is shown that Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) and Uridine diphosphate N-acetylglucosamine galactosamine (UDP-GalNAc), the main donors of glycosylation, in parallel with 1H NMR detected lipids, increased in apoptotic cancer cells.LDs in nervous system cancer cell lines contain specific lipid species. To the best of our knowledge, it is the first study mechanistically links UDP-GlcNAc and UDP-GalNAc to cancer cell death.

Iron is ubiquitous in the human body, fulfilling many crucial roles. However, accumulating evidence implicates excess iron as a carcinogen. This study aimed to further investigate the role of iron and haem in breast carcinogenesis and the potential utility of chelators in therapy. We demonstrate that the transport machinery for iron and haem is dysregulated in breast cancer, with import being promoted and export down-regulated to allow the accumulation of intra-cellular iron. In vitro studies demonstrate that, in contrast to benign cells, malignant cells are capable of importing haem as well as ionic iron. Both iron and haem stimulate aggressive behaviour in malignant cells, up-regulating viability, proliferation, adhesion, migration and invasion. These changes are abrogated by iron chelation. In addition, the expression profile of iron and haem transporters is shown to favour intra-cellular accumulation even when iron is plentiful and import would be expected to be down-graded. Overall this study suggests that breast cancer may be due to an inappropriate expression profile of iron and haem transporters, leading to excess intra-cellular iron which drives a malignant cell phenotype. In addition the action of chelators to downgrade malignant behaviour implies a potential therapeutic role.

Although knowledge of metabolic adaptations in cancer has increased dramatically, little is known about the spontaneous adoptive adaptations of cancer cells to changing conditions in the body. This is particularly important for chronic lymphocytic leukaemia (CLL) cells which continually circulate between different microenvironments in the blood, bone marrow and lymph nodes. To study such metabolic adaptations, a nuclear magnetic resonance (NMR) based approach; capable of monitoring real-time metabolism in primary CLL cells was developed. Using this setup, this thesis demonstrates fast, reversible metabolic plasticity in CLL cells during transition from normoxic to hypoxic conditions, associated with elevated HIF-1α dependent glycolysis. This work also demonstrates differential utilisation of pyruvate in oxygenated and hypoxic conditions where in the latter, pyruvate was actively transported into CLL cells to protect against oxidative stress. Moreover, real-time NMR experiments provided initial evidence that CLL metabolism in hypoxia correlates with stage of disease, adding significant relevance of our method for patient stratification. Additionally, to further investigate alterations between normoxic and hypoxic metabolism, Metabolic Flux Analysis (MFA) was carried out using primary CLL cell extracts, revealing modifications in pyruvate carboxylase (PC) activity and the pentose phosphate pathway (PPP). Despite the recent advent of promising new agents, CLL currently remains incurable and new therapeutic approaches are required. Understanding CLL cell adaptation to changing oxygen availability will permit the development of therapies that interfere with disease aetiology. This study makes several significant contributions towards this goal. Moreover, the findings may be relevant to all migratory cancer cells, and may have importance for the development of strategies to prevent cancer metastasis.

As a result of improvement in survival after childhood cancer, there are now increasing numbers of long-term survivors of childhood cancer living in the United Kingdom and across Europe. Specific groups of these childhood cancer survivors experience substantial excess risks of adverse health and social outcomes. Using the population-based British Childhood Cancer Survivor Study (BCCSS) the following areas were investigated: (I) The proportion of survivors on regular long-term hospital follow-up using risk stratification levels of care developed by the BCCSS in partnership with the National Cancer Survivorship Initiative. (2) The risks of adverse health and social outcomes using record-linkage and a self-reported questionnaire to assess which survivors of central nervous system tumours were at excess risk compared to the general population. (3) The risk of hospitalisation due to cerebrovascular conditions among childhood cancer survivors by electronic record linkage with Hospital Episode Statistics. Using the European PanCareSurFup cohort, the excess risks of genitourinary subsequent primary neoplasms were investigated among five-year survivors of childhood cancer. This thesis quantifies the risks experienced by childhood cancer survivors in four areas and provides an evidence-base for risk stratification by healthcare professionals caring for survivors.