<p>In eukaryotic cells, DNA is packaged into a structure named chromatin which contains DNA and proteins. Nucleosomes are building blocks of chromatin and contain DNA wrapped around a histone octamer. Chromatin modifications (histone post-translational modifications and histone variants) play central roles in various cellular processes including gene expression and DNA damage response. Chromatin modifying enzymes use metabolites as co-substrates and co-factors, and changes in metabolic pathways and metabolite availability affects chromatin modifications and chromatin-associated functions. Moreover, recent studies have uncovered direct roles of metabolic enzymes in chromatin-associated functions. Fumarase, a TCA cycle enzyme that catalyzes the reversible conversion of fumarate to malate in mitochondria (a hydration reaction), is an example of an enzyme with dual functions in metabolism and genome integrity. Cytoplasmic fraction of yeast fumarase, Fum1p, localizes to the nucleus and promotes growth upon DNA damage. Fum1p promotes homologous recombination by enhancing DNA end resection. Human fumarase is involved in DNA repair by non-homologous end joining. Here, we provide evidence that yeast Fum1p and the histone variant Htz1p are also involved in DNA replication stress response and DNA repair by non-homologous end joining (NHEJ). Using mutants lacking the histone variant <i>HTZ1</i>, we show that high cellular levels of fumarate, by deletion of <i>FUM1</i> or addition of exogenous fumarate, suppressed the sensitivity to DNA replication stress by modulation of activity of Jhd2p. This suppression required sensors and mediators of the intra-S phase checkpoint, but not factors involved in the processing of replication intermediates. These results imply that high cellular levels of fumarate can confer resistance to DNA replication stress by bypassing or complementing the defects caused by loss of <i>HTZ1</i> and replication fork processing factors. We also show that upon induction of DSBs, exogenous fumarate conferred resistance to mutants with defects in NHEJ, early steps of homologous recombination (DNA end resection pathway) or late steps of homologous recombination (strand invasion and exchange). Taken together, these results link the metabolic enzyme fumarase and the metabolite fumarate to DNA damage response and show that modulation of DNA damage response by regulating activity of chromatin modifying enzymes is a plausible pathway linking metabolism and nutrient availability to chromatin-associated functions like genome integrity.<br><a></a></p>

Cytogenetics is a study on the genetic considerations associated with structural and functional aspects of the cells with reference to chromosomal inclusions. Chromosomes are structures within the cells containing body's information in the form of strings of DNA. When atypical version or structural abnormality in one or more chromosomes prevails, it is defined as chromosomal aberrations (CA) depicting certain genetic pathogeny (known as genetic disorders). The present study assumes the presence of normal and abnormal chromosomal sets in varying proportions in the cytogenetic complex ; and, stochastical mixture theory is invoked to ascertain the information redundancy as a function of fractional abnormal chromosome population. This bioinformatic measure of redundancy is indicated as a track-parameter towards the progression of genetic disorder, for example, the growth of cancer. Lastly, using the results obtained, conclusions are enumerated, inferences are outlined and directions for future studies are considered. / by Jagadeshwari Karri. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

O câncer é uma das principais causas de morte em todo o mundo e o fator limitante na terapia antitumoral é a resistência a processos terapêuticos. Diversos são os mecanismos de resistência à drogas antitumorais e é fundamental desvendar os mecanismos envolvidos na quimiorresistência para eliminá-lo e ter-se uma melhor eficácia terapêutica. Nesse trabalho investigamos os mecanismos que determinam resistência a cisplatina em células de glioma. Primeiramente, mostramos que a resistência celular a cisplatina era independente de p53, capacidade de reparo de DNA. Utilizando modelo in vitro e in vivo foi demonstrado que os níveis de glutationa (GSH) tinha papel fundamental na resistência a cisplatina e temozolamida (TMZ). A linhagem de glioma resistente a TMZ tinha maior proteção antioxidante, maior expressão do fator de transcrição NRF2, GCLM e GST (envolvidos na geração e utilização de GSH). Utilizando modelo in vitro e in vivo mostramos que BSO (inibidor da síntese de GSH) potencializava o efeito tóxico do TMZ. Assim, a combinação de BSO com cisplatina e TMZ é uma abordagem poderosa para otimizar a citotoxicidade em tumores, sendo uma alternativa excitante para o tratamento de pacientes com glioma ou melanoma. / Cancer is one of main cause of death worldwide and the limiting factor is antitumoral therapy resistance. Several mechanisms command drug resistance and fundamental question is how is to unveil the mechanisms involved in it to get a better therapeutic efficacy. We investigated the mechanisms of cisplatin resistance in glioma cells. We demonstrated that cisplatin resistance was p53 independent and DNA repair capacity. It was demonstrated in a in vitro a in vivo model that gluthatione (GSH) is the major resistant factor for cisplatin and temozolomide (TMZ). We observed that the TMZ resistant glioma cell line counted with a high expression of the antioxidant transcription factor NFR2, GCLM and GST. We observed that NFR2 silencing greatly enhanced cell death, high levels of DNA damage upon TMZ treatment. In addition, BSO potentiated TMZ killing in human and murine melanoma using in vitro and in vivo models. Thus, combination of BSO, cisplatin and TMZ is a powerful strategy to optimize tumor killing, thus providing an exciting alternative therapeutic protocol to glioma and melanoma patients.

O Diabetes é uma das maiores causas de mortalidade no mundo, chegando a afetar cerca de 150 milhões de pessoas atualmente, sendo que esse número tende a aumentar, principalmente devido à obesidade, fator intimamente relacionado ao Diabetes Mellitus tipo 2 (DM2). Entretanto, o desenvolvimento da doença depende de diversos fatores de risco, tanto genéticos quanto ambientais, que ainda necessitam ser elucidados. Uma característica marcante dos pacientes diabéticos é um alto nível de estresse oxidativo, resultante principalmente da hiperglicemia e diminuição da defesa anti-oxidante. No presente trabalho, foi proposta a detecção dos níveis de dano no DNA pelo ensaio do cometa, assim como comparar os níveis de expressão de genes relacionados com a defesa, sinalização e reparo do DNA em resposta ao estresse oxidativo (ATM, ATR, SOD1, OGG1, XRCC1, APEX1 e FEN1) em pacientes DM2 hiperglicêmicos (PAH) e não hiperglicêmicos (PANH). Adicionalmente, o mesmo estudo foi realizado em pacientes DM2, cujas amostras foram coletadas em dois momentos: antes (PI) e após (PPI) um período de internação (sete dias) para compensação da doença e normalização dos níveis glicêmicos, comparativamente ao grupo controle. Na análise pelo ensaio do Cometa, o grupo PAH apresentou níveis significativamente (p<0,05) maiores de danos no DNA em relação ao grupo PANH, sendo que o último apresentou níveis de dano semelhantes ao grupo controle, demonstrando que a hiperglicemia é o principal fator na indução do estresse oxidativo em pacientes DM2. Com relação aos pacientes submetidos à internação por 7 dias, o grupo PPI apresentou níveis significativamente (p<0,05) menores de dano em relação ao grupo PI, embora estes tenham se apresentado acima dos observados para o grupo controle. A análise por qRT-PCR revelou perfis de expressão gênica diferenciados entre os grupos de pacientes estudados, embora as diferenças não tenham sido estatisticamente significativas. Observou-se uma repressão de genes de reparo e de sinalização (ATM, ATR, OGG1, XRCC1, FEN1 e APEX1) nos grupos PAH e PI, que apresentaram altos níveis de danos no DNA. Esse resultado pode apresentar um significado biológico relevante, sendo que na literatura, foram relatados resultados compatíveis com o estado de repressão transcricional de alguns desses genes, como os genes ATM e ATR. Os resultados obtidos demonstram a influência da hiperglicemia na indução de dano oxidativo no DNA. Além disso, os dados acerca da expressão gênica sugerem que pacientes DM2 regulam diferencialmente genes envolvidos com os processos de defesa, sinalização e reparo do DNA em resposta ao estresse oxidativo, o que pode estar relacionado com os níveis de dano observados em cada grupo analisado. Os mecanismos envolvidos na regulação desses processos são complexos e ainda necessitam ser elucidados, mas os dados do presente trabalho mostram informações relevantes que podem contribuir na compreensão desses mecanismos. / Diabetes is one of major causes of death in worldwide, resulting actually in approximately 150 million death per year, and it is becoming increasingly prevalent mostly due to obesity and overweight , that is associated related to Diabetes Mellitus type 2 (DM2). However, the development of DM2 is related to genetic and environmental risk factors which are not completely clarified. One of the most important aspects observed in DM2 patients is the presence of high oxidative stress in consequence of hyperglycemia and depletion of antioxidant defense. The present study aimed to evaluate DNA damage by the comet assay, as well as to compare expression levels of genes related to oxidative damage defense, signaling and DNA repair in response to oxidative stress (ATM, ATR, SOD1, OGG1, XRCC1, APEX1 and FEN1) in three different groups: hyperglycemic DM2 patients (PAH) and non hyperglycemic DM2 patients (PANH); DM2 patients prior (PI) and after (PPI) seven days of admission at the hospital, for the recovering of glycemic levels closely to normal levels. Analysis of DNA damage by the comet assay revealed significantly (p<0,05) higher levels of DNA damage in PAH group compared to PANH group, and the last group of non hyperglycemic patients exhibited damage levels similar to the control group, demonstrating that hyperglycemia is the most important factor that results in oxidative stress in DM2 patients. Considering the group of patients treated for 7 days, the PPI group exhibited lower levels of DNA damage when compared to PI group, although these levels remained higher than those observed for the control group. Gene expression analysis by the qRT-PCR showed different expression levels between groups of patients and controls, although the differences were not found significant by statistical analysis. Interestingly, DNA repair genes (ATM, ATR, OGG1, XRCC1, FEN1 and APEX1) were found repressed in those groups (PAH and PI) that exhibited high levels of DNA damage. These results may represent a relevant biological significance, since in light of literature data, it has been reported a down-regulation of ATM and ATR expression, either at transcription and protein levels. The present results demonstrated an influence of hyperglycemia in DNA damage induction in DM2 patients. In addition, the data regarding gene expression levels suggested that DM2 patients differentially regulate genes involved in antioxidant defense, signaling and DNA repair in response to oxidative stress. The mechanisms involved in the regulation of these pathways in DM2 patients are still poorly clarified. The present data constitute relevant information towards the understanding of these mechanisms.

Chan Chi Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 100-109). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / List of Abbreviations --- p.v / List of Tables --- p.vi / List of Figures --- p.vii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- "Free radicals, oxidative stress and antioxidants" --- p.2 / Chapter 1.1.1 --- Free radical and ROS --- p.2 / Chapter 1.1.2 --- Oxidative stress --- p.6 / Chapter 1.1.3 --- Antioxidants --- p.8 / Chapter 1.2 --- Plant as a source of antioxidants --- p.13 / Chapter 1.2.1 --- Common food sources of antioxidants --- p.13 / Chapter 1.2.2 --- Legume seeds as antioxidant sources --- p.15 / Chapter 1.3 --- Methods used to evaluate the antioxidant activity --- p.16 / Chapter 1.3.1 --- β-carotene bleaching method --- p.17 / Chapter 1.3.2 --- DPPH. scavenging method --- p.17 / Chapter 1.3.3 --- High-performance liquid chromatograph (HPLC) --- p.18 / Chapter 1.3.4 --- Single cell gel electrophoresis (SCGE) --- p.20 / Chapter 1.4 --- Objectives of the study --- p.22 / Chapter 2 --- Materials and Methods --- p.23 / Chapter 2.1 --- Plant materials and chemicals --- p.23 / Chapter 2.2 --- Sample preparation --- p.23 / Chapter 2.3 --- Determination of antioxidant activity using β-carotene bleaching method --- p.24 / Chapter 2.4 --- Evaluation of free radical scavenging ability --- p.26 / Chapter 2.5 --- HPLC separation of seed extract --- p.27 / Chapter 2.6 --- Evaluation of protective effects of legumes on the DNA damage using the comet assay --- p.28 / Chapter 2.6.1 --- Preparation of reagents --- p.28 / Chapter 2.6.2 --- Blood sample --- p.29 / Chapter 2.6.3 --- Hydrogen peroxide (H2O2) treatment --- p.29 / Chapter 2.6.4 --- Ethidium bromide-acridine orange (Et-Ac) viability determination --- p.31 / Chapter 2.6.5 --- Slide preparation --- p.31 / Chapter 2.6.6 --- Alkaline comet assay --- p.31 / Chapter 2.6.7 --- Quantification of DNA damage --- p.33 / Chapter 2.6.8 --- Statistical analysis --- p.33 / Chapter 3 --- Results --- p.40 / Chapter 3.1 --- General description of 24 selected legume seeds --- p.40 / Chapter 3.1 --- Determination of antioxidant activity using β-carotene bleaching method --- p.40 / Chapter 3.2 --- Evaluation of free radical scavenging ability --- p.43 / Chapter 3.3 --- Evaluation of protective effects of legumes on the DNA damage using the comet assay --- p.45 / Chapter 3.3.1 --- Optimal assay conditions --- p.46 / Chapter 3.3.2 --- Protective effects of seed extract and vitamin C --- p.47 / Chapter 3.3.3 --- Effects of heat treatment on the protective effect --- p.48 / Chapter 4 --- Discussion --- p.84 / Chapter 4.1 --- Methanolic extraction --- p.84 / Chapter 4.2 --- Antioxidant activities determined with β-carotene bleaching method and DPPH' scavenging method --- p.84 / Chapter 4.3 --- Evaluation of protective effects of legumes on the DNA damage using the comet assay --- p.93 / Chapter 4.3.1 --- H202-mediated DNA damage --- p.93 / Chapter 4.3.2 --- Protective effects of seed extracts and vitamin C --- p.94 / Chapter 5 --- Conclusion --- p.98 / References --- p.100

The term 'Retinitis pigmentosa' (RP) represents a group of inherited, late-onset diseases characterised by progressive retinal degeneration due to photoreceptor death. Mutations in the RP2 gene are found in 7-18% of patients with X-linked RP, one of the most severe forms. The RP2 gene product is a membrane-associated protein which encompasses two distinct domains. The N-terminal domain is well characterised as possessing GTPase-activating protein (GAP) activity towards the small GTPase ARL3 and thus regulate the transport of lipid-modified proteins within the photoreceptor cell. However, it is not known if the loss of this particular function of RP2 is the sole reason that causes the disease, while the role of the protein's C-terminus remains unknown. This thesis focuses on the characterisation of two novel protein-protein interactions of RP2 with the aim to investigate novel roles of the protein. Firstly, evidence is provided that a highly-conserved cluster of RP2 residues that span both the N- and C-terminus participate in direct interaction with Osteoclast-stimulating factor 1 (OSTF1). Two hypotheses are explored about the potential role of the complex in SRC-mediated RP2 phosphorylation and the regulation of cell motility. Secondly, the catalytic subunit of DNA-dependent protein kinase (DNA PK) is identified as a novel interaction partner of RP2 in cultured cells. The two proteins are shown to co-localise in the nuclear and membrane compartments of a retinal-derived cell line and might engage in a kinase-substrate relationship. So far, no evidence was found that RP2 participates in the canonical function of DNA PK which is the regulation of DNA double-stranded breaks. Finally, the CRISPR/Cas9 genome editing method was applied on zebrafish embryos to generate a novel vertebrate animal model for the loss of RP2 function. One out of three different zebrafish lines with rp2 mutations was shown by histology to have mild late-onset thinning of the photoreceptor outer segments. The present thesis reports previously unexplored aspects of RP2's function and will, therefore, contribute to understanding the molecular mechanisms that underlie RP. Moreover, this thesis will contribute to the discussion about the usefulness of zebrafish as an RP model.

Orientador: Ilda de Godoy / Resumo: O tabagismo é responsável pelo maior número de mortes evitáveis ​​no mundo e está relacionado ao desenvolvimento de várias doenças, principalmente a doença pulmonar obstrutiva crônica (DPOC). Assim, a busca por biomarcadores precoces torna-se relevante para sua identificação e para o sucesso terapêutico. Os objetivos do nosso estudo foram avaliar a concentração da proteína de choque térmico 70 (HSP70), expressão do gene HSP70, anticorpos anti-HSP70 auto, marcador inflamatório sistêmico através da citocina interleucina-8 (IL-8) e proteína C reativa (PCR), alterações imunológicas e danos no DNA no sangue periférico de fumantes crônicos assintomáticos e não fumantes. Nossos resultados mostraram concentrações séricas aumentadas de HSP70, anti-HSP70, IL-8, PCR e neutrófilos, e danos no DNA de células sanguíneas de fumantes em comparação ao não-fumantes. Portanto, o tabagismo foi responsável por levar a alteração nos parâmetros fisiológicos e moleculares associados ao risco de desenvolver DPOC e outras doenças pulmonares. Com base nos dados, sugerimos que a HSP70 pode ser responsável pelo aumento dos níveis de citocinas inflamatórias e, consequentemente, o aumento do influxo de neutrófilos para os pulmões e aumento dos danos ao DNA e auto-anticorpos anti-HSP70. / Abstract: Smoking is responsible for the largest number of preventable deaths in the world, and is related to the development of several diseases, mainly chronic obstructive pulmonary disease (COPD). Thus, the search for early biomarkers of such diseases becomes relevant for their identification and for successful therapy. The objectives of our study were to evaluate the concentration of heat shock protein 70 (HSP70), expression of the HSP70 gene, anti-HSP70 auto antibodies, the systemic inflammatory marker through cytokine interleukin-8 (IL-8) and CPR, immunological changes and DNA damage in peripheral blood of chronic asymptomatic smokers and non-smokers. Our results showed increased serum concentrations of HSP70, anti-HSP70, IL-8, CPR and neutrophils, and DNA damage in blood cells of smokers than in non-smokers. Therefore, cigarette smoking was confirmed as a noxious agent on physiological and molecular parameters associated with the risk for developing COPD and other lung diseases. Based on the data we suggest that HSP70 can be responsible for the increased levels of inflammatory cytokines, and consequently, the increased influx of neutrophils into the lungs and increased DNA damages e anti-HSP70 auto antibodies. / Doutor

Mammalian cells possess a variety of different DNA repair pathways, which work together to safeguard genomic integrity upon encountering different types of DNA damage. Among all lesions, DNA double-strand breaks (DSBs) are most toxic and, if left unrepaired, results in loss of genetic information and genomic instability- a hallmark of tumorigenesis. Ataxia Telangiectasia Mutated (ATM) is a protein kinase, a master regulator of the DNA damage response, and is activated upon the formation of DSBs. ATM senses DNA DSBs through its accessory proteins and functions as a transducer of the DNA damage response (DDR), which entails the activation of genes involved in DNA repair, cell cycle checkpoint, and apoptosis. Consequently, loss of ATM results in increased genomic instability and compromised checkpoint regulation. Moreover, loss of ATM has been reported in various human cancers, and Atm-deficient mice uniformly develop thymic lymphomas, highlighting its role as a tumor suppressor. Although ATM has been extensively studied, much of its known functions to date pertained to its kinase activity, and the structural function of ATM remains elusive. To investigate whether ATM possesses structural functions beyond its kinase activity, we generated a mouse model expressing kinase-dead (KD) ATM protein. Intriguingly, while Atm-/- are viable, AtmKD/KD and AtmKD/- mice were embryonic lethal and AtmKD/KD and AtmKD/- cells displayed greater genomic instability compared to ATM-null cells, suggesting that the presence of the ATM KD protein blocks additional DNA repair pathways that are not affected in ATM-null cells. In this context, we identified defects in homologous recombination, resolution of Camptothecin (CPT)-induced Topoisomerase-I lesions, and replication progression specifically in AtmKD/- cells beyond those observed in Atm-/-. Mouse model expressing KD ATM (AtmKD/-) in hematopoietic stem cells (HSCs) developed thymic lymphomas faster and more frequently than the corresponding model with the ATM-null HSCs, which was associated with increased genomic instability and loss of tumor-suppressor Pten. In collaboration with others, we showed that the majority of tumor-associated ATM mutations reported in TCGA are missense mutations and are highly enriched in the kinase domain, while Ataxia-Telangiectasia (A-T) associated germline ATM mutations are almost always truncating mutations leading to complete loss of ATM protein. This result suggests that ATM KD protein might be expressed in a significant fraction of human cancer. These results, for the first time, identified a previously unknown phosphorylation-dependent, structural function of ATM in the maintenance of genomic integrity and tumor suppression. Furthermore, the tumorigenicity and vulnerability to particular DNA damaging agents caused by the expression of the ATM KD protein relative to the loss of ATM highlight the importance of distinguishing the types of ATM mutations in tumors, and provide novel insights into the clinical use of specific ATM kinase inhibitors, as well as the prognosis and treatments of ATM-mutated cancers. ATM has been reported to be frequently inactivated in human B-cell lymphomas, including up to 50% Mantle Cell Lymphoma (MCL), which represents around 6% of all Non-Hodgkins Lymphomas (NHLs). MCL is characterized by the recurrent t(11;14)(q13;q32) translocation, which juxtaposes CCND1/BCL-1 to the IGH enhancer, leading to deregulated expression of CyclinD1 (CCND1). However, CyclinD1 overexpression in B cells alone is not sufficient to induce MCL in mouse models, and the role of ATM in the suppression of B-cell lymphomas is not well understood, in part due to the lack of ATM-deficient mature B-cell lymphoma models. To address this, we generated a mouse model that combines conditional deletion of ATM specifically in early progenitor B-cells via Mb1cre, and overexpressing CyclinD1 in lymphoid cells via EµCyclinD1 transgene. While ATM loss alone resulted in the development of indolent, clonal, mature B-cell lymphoma, combined ATM-loss and CyclinD1 overexpression accelerated and increased the incidence of B-cell lymphoma. Furthermore, ATM-loss combined with CyclinD1 overexpression led to greater genomic instability and the expansion of naïve ATM-deficient B-cells in the spleen. This study, for the first time, developed an ATM-deficient B-cell lymphoma model and demonstrated a synergistic function of ATM and CyclinD1 in pre-GC B-cell proliferation and lymphomagenesis. Furthermore, the mice described here provide a prototypic animal model to study the pathogenesis of human MCL, for which there are no suitable mouse models.

A vitamina D3 é um micronutriente obtido da dieta ou pela conversão do 7- dehidrocolesterol na epiderme após exposição à radiação UVB. A vitamina D (D2 ou D3) atua sobre o sistema renina-angiotensina-aldosterona, e sua deficiência vem sendo associada ao desenvolvimento da hipertensão. O objetivo deste estudo foi avaliar o efeito da suplementação ou deficiência de vitamina D3 em ratos espontaneamente hipertensos (SHR - spontaneously hypertensive rats) e seus controles normotensos (Wistar Kyoto - WKY) sobre a pressão arterial sistólica, danos ao DNA e cromossomos, marcadores bioquímicos do estresse oxidativo, burst oxidativo dos neutrófilos, análise de fibrose no rim e perfil de expressão de genes relacionados com a hipertensão arterial no rim e coração. Os animais foram alimentados com dieta controle (1.000 UI/kg), suplementada (10.000 UI/kg) ou deficiente (0 UI/kg) em vitamina D3 ao longo de 12 semanas. A quantificação plasmática de vitamina D3 foi avaliada pelo método ELISA (Enzyme-Linked Immunosorbent Assay) e a pressão arterial sistólica foi aferida semanalmente, por método não invasivo de pletismografia da artéria caudal. Os danos ao material genético foram avaliados pelo ensaio do cometa nas células do sangue periférico, rim e coração e pelo teste do micronúcleo nos eritrócitos da medula óssea e sangue periférico; o estresse oxidativo foi avaliado pelos ensaios de quantificação das substâncias reativas ao ácido tiobarbitúrico (TBARS - Thiobarbituric Acid Reactive Substances) e glutationa (GSH) no rim e coração; o burst oxidativo em neutrófilos do sangue periférico; a quantificação de fibrose por histologia renal e a expressão gênica por RT2 ProfilerTM PCR Arrays no rim e coração. Os resultados obtidos com os ratos SHR mostraram que a suplementação com vitamina D3 reduziu a pressão arterial sistólica, não induziu danos ao DNA e aos cromossomos, estresse oxidativo ou fibrose renal, e regulou a expressão de quatro genes envolvidos com a hipertensão arterial no rim (Ace, Agt, Ren e Edn1) e cinco genes no coração (Ace, Avp, Ephx2, Mylk3 e Ren). A deficiência em vitamina D3 aumentou a pressão arterial sistólica, os danos ao DNA e aos cromossomos, a peroxidação lipídica no rim e coração, o burst oxidativo dos neutrófilos, o percentual de fibrose no rim, e a expressão de treze genes envolvidos com a hipertensão arterial no rim (Ace, Acta2, Agt, Agtr1a, Agtr1b, Alox5, Cacna1c, Ece1, Ednra, Kcnma1, P2rx4, Scnn1g e Slc7a1) e nove genes no coração (Ace, Agtr1b, Cacna1c, Drd5, Mylk2, Nostrin, Scnn1a, Scnn1g e Sphk1). Nos animais WKY, a dieta suplementada alterou a expressão do gene Ren no rim e de dez genes no coração (Ace2, Bdkrb2, Drd3, Drd5, Itpr1, Itpr2, Itpr3, Ptgs1, Scnn1a e Scnn1g); e a dieta deficiente em vitamina D3 aumentou os danos ao DNA nos eritrócitos, induziu fibrose no rim e alterou a expressão de três genes no rim (Ace, Cps1 e Arg2) e de seis genes no coração (Ace, Cacna1c, Edrna, Ephx2, Itpr1 e Itpr2). Nos parâmetros pressão arterial sistólica, danos aos cromossomos, peroxidação lipídica e burst oxidativo, os ratos WKY alimentados com as dietas suplementada ou deficiente em vitamina D3 não diferiram em relação aos animais que receberam a dieta controle. Em conclusão, a variação da concentração de vitamina D3 da dieta alterou a fisiologia da hipertensão arterial, atuando como um anti-hipertensivo na suplementação e agravando os efeitos da hipertensão na deficiência. / Vitamin D3 is a micronutrient obtained from diet or by conversion of 7- dehydrocholesterol in the skin after exposure to UVB radiation. Vitamin D (D2 or D3) acts on the renin-angiotensin-aldosterone system, and its deficiency has been associated with hypertension development. This study aimed to evaluate the effect of vitamin D3 supplementation or deficiency in spontaneously hypertensive rats (SHR - spontaneously hypertensive rats) and their normotensive controls (Wistar Kyoto - WKY) on systolic blood pressure, DNA and chromosomes damage, biochemical markers of oxidative stress, oxidative burst in neutrophils, renal fibrosis and the gene expression profile of genes related to hypertension in kidney and heart. The rats were fed a vitamin D3 control diet (1,000 IU/kg) supplemented diet (10,000 IU/kg) or deficient diet (0 IU / kg) during 12 weeks. Vitamin D3 plasma quantification was performed by ELISA (Enzyme-Linked Immunosorbent Assay) technique and systolic blood pressure was measured weekly by noninvasive plethysmography of the caudal artery. DNA and chromosomal damage was evaluated by the comet assay in the peripheral blood, kidney and heart cells and by the micronucleus test in erythrocytes from bone marrow and peripheral blood; oxidative stress was evaluated by thiobarbituric acid reactive substances (TBARS) and glutathione (GHS) assays in kidney and heart; oxidative burst in neutrophils of peripheral blood; renal fibrosis by histology and gene expression by RT2 ProfilerTM PCR Arrays in kidney and heart. The results obtained for SHR rats showed that vitamin D3 supplementation reduced systolic blood pressure, did not induced DNA or chromosomal damage, oxidative stress or renal fibrosis, and regulated the expression of four genes involved with hypertension in the kidney (Ace, Agt, Ren and Edn1) and five genes in the heart (Ace, Avp, Ephx2, Mylk3 and Ren). Vitamin D3 deficiency increased systolic blood pressure, DNA damage in erythrocytes, lipid peroxidation in kidney and heart, oxidative burst in neutrophils and the renal fibrosis, and regulates the expression of thirteen genes involved with hypertension in kidney (Ace, Acta2, Agt, Agtr1a, Agtr1b, Alox5, Cacna1c, Ece1, Ednra, Kcnma1, P2rx4, Scnn1g and Slc7a1) and nine genes in heart (Ace, Agtr1b, Cacna1c, Drd5, Mylk2, Nostrin, Scnn1a, Scnn1g and Sphk1). In WKY rats, vitamin D3 supplementation altered the expression of Ren gene in the kidney and of ten genes in the heart (Ace2, Bdkrb2, Drd3, Drd5, Itpr1, Itpr2, Itpr3, Ptgs1, Scnn1a and Scnn1g); and vitamin D3 deficiency increased DNA damage in erythrocytes and renal fibrosis, and altered the expression of three genes in the kidney (Ace, Cps1 and Arg2) and six genes in the heart (Ace, Cacna, Ednra, Ephx2, Itpr1 and Itpr2). In the parameters systolic blood pressure, chromosomal damage, lipid peroxidation and oxidative burst, WKY rats fed with vitamin D3 supplemented or deficient diet did not differ compared to rats that received vitamin D3 control diet. In conclusion, the variation of dietary vitamin D3 levels altered the physiology of hypertension, acting as an antihypertensive in supplementation and aggravating the hypertension effects in its deficiency.

Breast cancer is the most commonly occurring cancer in women, with incidence rates approaching 1.38 million cases per year worldwide. Over the last few decades, there have been numerous attempts to develop, synthesise and advance into the clinic novel and selective breast cancer therapies. Research work has shown that bisnaphthalimidopropyl diaminodicyclohexylmethane (BNIPDaCHM) exerts potent in vitro anti-cancer activities and strong DNA binding properties. The aim of this thesis was to synthetise novel bisnaphthalimidopropyl derivatives (BNIPs) and investigate their subsequent modes of action within two human metastatic breast cancer cell lines, MDA-MB-231 and SKBR-3. A series of novel BNIPs, bisnaphthalimidopropyl-piperidylpropane (BNIPPiProp), bisnaphthalimidopropyl- ethylenedipiperidine (BNIPPiEth) and (trans(trans))-4,4’-methylenebis-cyclohexylamine (trans,trans-BNIPDaCHM) were synthesised, characterised and studied in comparison to BNIPDaCHM for their DNA binding and anti-cancer activities against MDA-MB-231 and SKBR-3 cells. Thermal denaturation studies have shown that BNIPs can intercalate and stabilize the double helix of Calf Thymus, each BNIP can competitively displace EtBr from DNA in a dose dependent manner and by UV binding studies, high affinity was found for the three novel BNIPs. After 24 hours treatment, all novel BNIPs, exhibited strong cytotoxicity with IC50 values ranging from 1.4 μM to 3.3 μM in MDA-MB-231 cells and 0.2 - 0.7 μM in SKBR-3 cells, confirming the importance of bisnaphthalimidopropyl functionality. BNIPs were also found to increase intracellular ROS levels after 8 hours treatment and induce a significant increase in DNA strand breaks compared to endogenous levels, after 24 hour treatment in both cell lines. After cell synchronisation, cell cycle distribution was studied, revealing that trans,trans-BNIPDaCHM induces sub-G1 cell population arrest in MDA-MB-231 and SKBR-3 cells, after 24 hours treatment. In addition, BNIPs induced apoptotic phosphatidylserine exposure, after 0.5 hours treatment, inhibited Caspase-3 activity and increased autophagy, after 24 hour treatment in MDA-MB-231 and SKBR-3 cells. Moreover, BNIPs inhibited histone deacetylases (HDAC) activity after 24 hours treatment in MDA-MB-231 and SKBR-3 cells and BNIPDaCHM was identified as a potential SIRT2 inhibitor, in SKBR-3 cells. According to Proteome Profiler Arrays, BNIPDaCHM and BNIPPiEth altered the expression of cell stress-related proteins in a cell dependent manner and bioinformatic analysis revealed two novel, putative pathways for BNIP-induced oxidative stress-mediated cell death in MDA-MB-231 and SKBR-3 cells. The above findings indicate that BNIPs represent promising candidates for future breast cancer studies and cancer treatment.