The IGF system is a crucial regulator of normal growth and development, however dysregulation of the system on multiple levels is associated with the incidence of a wide variety of malignancies including the breast, thyroid, lung, and colon, making the IGF system an important anti-cancer therapeutic target. Due to its role in mediating cellular proliferation, protection from apoptosis, and metastasis, traditional focus has been set on examining the role of the type 1 IGF receptor [IGF1R] in cancer. However there is mounting evidence to suggest the insulin receptor [IR] may also be involved in the potentiation and pathogenesis of cancers. The observation that IGF-II is overexpressed, compared to normal tissues, by cancers suggests signaling via target receptors by this ligand has important implications on cancer pathogenesis. Indeed, both the IGF1R and IR have been demonstrated to be up-regulated in a variety of malignancies. In regards to IR isoform, the IGF-II binding IR-A is preferentially expressed by a number of cancer cell types. Together with the observation that an autocrine proliferative loop exists between IGF-II and the IR-A in malignant thyrocytes and cultured breast cancer cells, suggests signaling via the IR-A may play a role in cancer cell growth and survival. However, very few studies on the IR-A have been conducted in cells co-expressing the IGF1R. This is mainly due to the difficulties associated with discrimination between signaling arising from IGF1R homodimers, IR-A homodimers, and IGF1R/IR-A hybrid receptors. It is not known how the IR-A interacts, and functions in conjunction with the other receptors of the IGF system to signal biologically relevant outcomes, especially in terms of anti-cancer therapeutics that aim to block and down-regulate the IGF1R. Current anti-cancer therapies targeting the IGF system have concentrated on blocking IGF signaling via the IGF1R, due mostly to the functional properties of the receptor, but also in part due to the metabolic consequences associated with blockade and inhibition of the IR. This individual targeting of the IGF1R potentially leaves a pathway by which IGF-II secreted by the tumour can circumvent current IGF1R based therapies. Consequently, this thesis investigated whether the IR-A could compensate for the targeted loss of the IGF1R and how the IR-A interacts with the IGF1R in cells co-expressing these two receptors. In addition, the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation was assessed. The main experimental techniques used throughout this body of work included; assessment of protein expression and activation by Western blot, siRNA mediated gene silencing, and measures of cell proliferation, survival, and migration. The key areas of investigation included: 1. Investigation of the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation 2. Identification of an appropriate cell line model in which to investigate the interactions between the IR-A and IGF1R 3. Optimisation of siRNA mediated knock-down of the IR-A and IGF1R in SW480 colorectal adenocarcinoma cells 4. Determination of the biological role of the IR-A in SW480 cells co-expressing the IGF1R The key findings from this work included: 1. The IR-A could not compensate for IGF1R depletion in SW480 cells 2. Dual silencing of the IR-A and IGF1R indicated signaling via the IGF1R was dominant to signaling via the IR-A in SW480 cells 3. Signaling via IR-A/IGF1R hybrid receptors may not be as potent as signaling via IGF1R homodimers 4. IGF-I at physiological concentrations can stimulate biological responses via both isoforms of the IR. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337339 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

The IGF system is a crucial regulator of normal growth and development, however dysregulation of the system on multiple levels is associated with the incidence of a wide variety of malignancies including the breast, thyroid, lung, and colon, making the IGF system an important anti-cancer therapeutic target. Due to its role in mediating cellular proliferation, protection from apoptosis, and metastasis, traditional focus has been set on examining the role of the type 1 IGF receptor [IGF1R] in cancer. However there is mounting evidence to suggest the insulin receptor [IR] may also be involved in the potentiation and pathogenesis of cancers. The observation that IGF-II is overexpressed, compared to normal tissues, by cancers suggests signaling via target receptors by this ligand has important implications on cancer pathogenesis. Indeed, both the IGF1R and IR have been demonstrated to be up-regulated in a variety of malignancies. In regards to IR isoform, the IGF-II binding IR-A is preferentially expressed by a number of cancer cell types. Together with the observation that an autocrine proliferative loop exists between IGF-II and the IR-A in malignant thyrocytes and cultured breast cancer cells, suggests signaling via the IR-A may play a role in cancer cell growth and survival. However, very few studies on the IR-A have been conducted in cells co-expressing the IGF1R. This is mainly due to the difficulties associated with discrimination between signaling arising from IGF1R homodimers, IR-A homodimers, and IGF1R/IR-A hybrid receptors. It is not known how the IR-A interacts, and functions in conjunction with the other receptors of the IGF system to signal biologically relevant outcomes, especially in terms of anti-cancer therapeutics that aim to block and down-regulate the IGF1R. Current anti-cancer therapies targeting the IGF system have concentrated on blocking IGF signaling via the IGF1R, due mostly to the functional properties of the receptor, but also in part due to the metabolic consequences associated with blockade and inhibition of the IR. This individual targeting of the IGF1R potentially leaves a pathway by which IGF-II secreted by the tumour can circumvent current IGF1R based therapies. Consequently, this thesis investigated whether the IR-A could compensate for the targeted loss of the IGF1R and how the IR-A interacts with the IGF1R in cells co-expressing these two receptors. In addition, the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation was assessed. The main experimental techniques used throughout this body of work included; assessment of protein expression and activation by Western blot, siRNA mediated gene silencing, and measures of cell proliferation, survival, and migration. The key areas of investigation included: 1. Investigation of the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation 2. Identification of an appropriate cell line model in which to investigate the interactions between the IR-A and IGF1R 3. Optimisation of siRNA mediated knock-down of the IR-A and IGF1R in SW480 colorectal adenocarcinoma cells 4. Determination of the biological role of the IR-A in SW480 cells co-expressing the IGF1R The key findings from this work included: 1. The IR-A could not compensate for IGF1R depletion in SW480 cells 2. Dual silencing of the IR-A and IGF1R indicated signaling via the IGF1R was dominant to signaling via the IR-A in SW480 cells 3. Signaling via IR-A/IGF1R hybrid receptors may not be as potent as signaling via IGF1R homodimers 4. IGF-I at physiological concentrations can stimulate biological responses via both isoforms of the IR. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337339 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

The IGF system is a crucial regulator of normal growth and development, however dysregulation of the system on multiple levels is associated with the incidence of a wide variety of malignancies including the breast, thyroid, lung, and colon, making the IGF system an important anti-cancer therapeutic target. Due to its role in mediating cellular proliferation, protection from apoptosis, and metastasis, traditional focus has been set on examining the role of the type 1 IGF receptor [IGF1R] in cancer. However there is mounting evidence to suggest the insulin receptor [IR] may also be involved in the potentiation and pathogenesis of cancers. The observation that IGF-II is overexpressed, compared to normal tissues, by cancers suggests signaling via target receptors by this ligand has important implications on cancer pathogenesis. Indeed, both the IGF1R and IR have been demonstrated to be up-regulated in a variety of malignancies. In regards to IR isoform, the IGF-II binding IR-A is preferentially expressed by a number of cancer cell types. Together with the observation that an autocrine proliferative loop exists between IGF-II and the IR-A in malignant thyrocytes and cultured breast cancer cells, suggests signaling via the IR-A may play a role in cancer cell growth and survival. However, very few studies on the IR-A have been conducted in cells co-expressing the IGF1R. This is mainly due to the difficulties associated with discrimination between signaling arising from IGF1R homodimers, IR-A homodimers, and IGF1R/IR-A hybrid receptors. It is not known how the IR-A interacts, and functions in conjunction with the other receptors of the IGF system to signal biologically relevant outcomes, especially in terms of anti-cancer therapeutics that aim to block and down-regulate the IGF1R. Current anti-cancer therapies targeting the IGF system have concentrated on blocking IGF signaling via the IGF1R, due mostly to the functional properties of the receptor, but also in part due to the metabolic consequences associated with blockade and inhibition of the IR. This individual targeting of the IGF1R potentially leaves a pathway by which IGF-II secreted by the tumour can circumvent current IGF1R based therapies. Consequently, this thesis investigated whether the IR-A could compensate for the targeted loss of the IGF1R and how the IR-A interacts with the IGF1R in cells co-expressing these two receptors. In addition, the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation was assessed. The main experimental techniques used throughout this body of work included; assessment of protein expression and activation by Western blot, siRNA mediated gene silencing, and measures of cell proliferation, survival, and migration. The key areas of investigation included: 1. Investigation of the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation 2. Identification of an appropriate cell line model in which to investigate the interactions between the IR-A and IGF1R 3. Optimisation of siRNA mediated knock-down of the IR-A and IGF1R in SW480 colorectal adenocarcinoma cells 4. Determination of the biological role of the IR-A in SW480 cells co-expressing the IGF1R The key findings from this work included: 1. The IR-A could not compensate for IGF1R depletion in SW480 cells 2. Dual silencing of the IR-A and IGF1R indicated signaling via the IGF1R was dominant to signaling via the IR-A in SW480 cells 3. Signaling via IR-A/IGF1R hybrid receptors may not be as potent as signaling via IGF1R homodimers 4. IGF-I at physiological concentrations can stimulate biological responses via both isoforms of the IR. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337339 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

The IGF system is a crucial regulator of normal growth and development, however dysregulation of the system on multiple levels is associated with the incidence of a wide variety of malignancies including the breast, thyroid, lung, and colon, making the IGF system an important anti-cancer therapeutic target. Due to its role in mediating cellular proliferation, protection from apoptosis, and metastasis, traditional focus has been set on examining the role of the type 1 IGF receptor [IGF1R] in cancer. However there is mounting evidence to suggest the insulin receptor [IR] may also be involved in the potentiation and pathogenesis of cancers. The observation that IGF-II is overexpressed, compared to normal tissues, by cancers suggests signaling via target receptors by this ligand has important implications on cancer pathogenesis. Indeed, both the IGF1R and IR have been demonstrated to be up-regulated in a variety of malignancies. In regards to IR isoform, the IGF-II binding IR-A is preferentially expressed by a number of cancer cell types. Together with the observation that an autocrine proliferative loop exists between IGF-II and the IR-A in malignant thyrocytes and cultured breast cancer cells, suggests signaling via the IR-A may play a role in cancer cell growth and survival. However, very few studies on the IR-A have been conducted in cells co-expressing the IGF1R. This is mainly due to the difficulties associated with discrimination between signaling arising from IGF1R homodimers, IR-A homodimers, and IGF1R/IR-A hybrid receptors. It is not known how the IR-A interacts, and functions in conjunction with the other receptors of the IGF system to signal biologically relevant outcomes, especially in terms of anti-cancer therapeutics that aim to block and down-regulate the IGF1R. Current anti-cancer therapies targeting the IGF system have concentrated on blocking IGF signaling via the IGF1R, due mostly to the functional properties of the receptor, but also in part due to the metabolic consequences associated with blockade and inhibition of the IR. This individual targeting of the IGF1R potentially leaves a pathway by which IGF-II secreted by the tumour can circumvent current IGF1R based therapies. Consequently, this thesis investigated whether the IR-A could compensate for the targeted loss of the IGF1R and how the IR-A interacts with the IGF1R in cells co-expressing these two receptors. In addition, the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation was assessed. The main experimental techniques used throughout this body of work included; assessment of protein expression and activation by Western blot, siRNA mediated gene silencing, and measures of cell proliferation, survival, and migration. The key areas of investigation included: 1. Investigation of the individual ability of the IR isoforms to signal biological outcomes in response to IGF stimulation 2. Identification of an appropriate cell line model in which to investigate the interactions between the IR-A and IGF1R 3. Optimisation of siRNA mediated knock-down of the IR-A and IGF1R in SW480 colorectal adenocarcinoma cells 4. Determination of the biological role of the IR-A in SW480 cells co-expressing the IGF1R The key findings from this work included: 1. The IR-A could not compensate for IGF1R depletion in SW480 cells 2. Dual silencing of the IR-A and IGF1R indicated signaling via the IGF1R was dominant to signaling via the IR-A in SW480 cells 3. Signaling via IR-A/IGF1R hybrid receptors may not be as potent as signaling via IGF1R homodimers 4. IGF-I at physiological concentrations can stimulate biological responses via both isoforms of the IR. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337339 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

Colorectal cancer (CRC) is a major problem in affluent countries worldwide. In Australia it is the second most commonly diagnosed malignancy with approximately 13,000 new cases diagnosed each year. This disease is also the leading cause of cancer related death in Australia with approximately 4,500 fatalities each year. Epidemiological studies have shown geographical variation in the incidence of disease, with diet considered to be a key contributing factor to CRC risk. In particular, diets high in fibre and low in fat have been demonstrated to reduce the risk of developing CRC. Fibre is heterogeneous in nature and can be categorised into different subtypes. Resistant starch is a component of fibre which remains largely intact throughout the gastrointestinal tract until it reaches the colon. Here it undergoes bacterial fermentation to produce the short chain fatty acids (SCFAs) acetate, propionate and butyrate (BuA). Each of the SCFAs are bioactive in the colon, with the most active being BuA. The beneficial effects of fibre have been linked to BuA’s ability to induce colon cancer cell differentiation, reduce proliferation and initiate apoptosis. Interestingly, in normal cells BuA is utilised as the preferential energy source and has been shown to promote proliferation. With an apparent “paradoxical effect” on normal and cancerous cells BuA has been the subject of much investigation as a potential anticancer agent. Despite numerous studies investigating BuA actions, the exact biological mechanisms remain largely undefined. This thesis explored a possible mechanism for BuA-induced apoptosis and inhibition of proliferation. In 2003, two publications provided evidence that SCFAs, including BuA, were ligands to two members of a previously orphan family of G-protein coupled receptors (GPCRs); GPCR41 and 43. Of the two receptors BuA had the strongest effect on GPCR43. Consequently this thesis investigated the possibility that BuA acts to decrease CRC proliferation and induce apoptosis by binding to and activating GPCR43 on CRC cells. It was hypothesised that GPCR43 acted as a “BuA sensor” on the surface of the cell to mediate the effects of BuA. This experimental work utilised PCR, Q-PCR, measures of apoptosis, proliferation and differentiation and RNAi knockdown. The key areas of investigation included: (1) Determining if GPCR43 was present on a range of CRC cell lines with a cell line to represent adenocarcinoma, carcinoma and metastatic stage of disease. (2) Investigating the expression of GPCR43 with manipulated nutrient media and different levels of cell confluence. (3) Exploring GPCR43 expression in normal and malignant human patient biopsies. (4) Determining if the inhibition of G-protein function using inhibitors influenced BuAinduced changes to apoptosis and proliferation. (5) Using RNAi, investigating the effect that GPCR43 knockdown would have on BuA-induced changes to proliferation and apoptosis. The key findings from this work included: (1) Presence of GPCR43 on some but not all CRC cell lines. (2) Modulation of GPCR43 expression with exposure to BuA and altered glucose concentrations in the media. (3) An influence of G-protein inhibition on BuA-induced apoptosis but not proliferation in some cell lines. (4) GPCR43 knockdown using RNAi indicated that GPCR43 is not exclusively required for BuA to regulate apoptosis and proliferation. The results from this work indicate that GPCR43 is not likely to exclusively mediate BuA’s effects, but opens up new areas of research into the exact role of GPCR43 on CRC cells. / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2008

Made available in DSpace on 2015-03-03T11:52:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-26Bitstream added on 2015-03-03T12:07:07Z : No. of bitstreams: 1 000808319.pdf: 876369 bytes, checksum: 3244e6e3938737edaba8e2c8144fa57a (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Investigamos as repercussões do padrão alimentar ocidental, rico em gordura, (óleo de milho) (20%) e pobre em micronutrientes [ácido fólico (1 mg/g), colina (0,12%) e fibra (2%)], ocorrido durante a gestação, lactação e puberdade na susceptibilidade ao desenvolvimento de câncer do cólon induzido pela 1,2-dimetilhidrazina (DMH) no rato. Avaliamos se a reintrodução da dieta Ocidental durante a vida adulta em animais previamente expostos à dieta Ocidental durante a vida intrauterina, lactação e puberdade, pode modificar a susceptibilidade à oncogênese do cólon pela DMH. Ratas fêmeas SD prenhes receberam dieta semi-purificada controle (AIN-93) ou do tipo Ocidental (WD - Western Style Diet) a partir do dia gestacional 12 (DG 12). Após o desmame (dia 21), a prole de machos permaneceu com o mesmo tipo de dieta de suas mães até o dia pós-natal 50 (DPN 50). Nesse momento, receberam quatro injeções subcutâneas de DMH (40mg/kg) e foram divididos nos seguintes grupos/dietas: Grupo I (AIN-93/DMH/AIN-93) recebeu dieta controle durante todo o experimento (DG 12- DPN 370), o Grupo II (AIN-93/DMH/Ocidental) recebeu dieta Ocidental somente na vida adulta, a partir do DPN 260, Grupo III (Ocidental/DMH/AIN-93) recebeu dieta Ocidental desde a vida intrauterina até o início da puberdade (DG 12 - DPN 50), e o Grupo IV (Ocidental/DMH/Ocidental) recebeu dieta Ocidental desde a vida intrauterina até o início da puberdade (DG 12 - DPN 50), e foi reintroduzido à dieta Ocidental na vida adulta (DPN 260). Todos os animais foram eutanasiados ao final da 50ª semana de experimento (DPN 370). O cólon foi removido e submetido à análise estereoscópica e histológica para determinar o número, distribuição e multiplicidade dos focos de criptas aberrantes (FCAs). As características das lesões neoplásicas e os níveis séricos de insulina e leptina foram analisados à necropsia. A exposição à dieta Ocidental durante a gestação, ... / We examined the effects of a Western Style Diet (WD), high in fat (corn oil) (20%) and low in micronutrients [i.e.; folic acid (1 mg/g), choline (0.12%) and fiber (2%)] during pregnancy, lactation and in prepubertal stage to examine the susceptibility to colon carcinogenesis induced by dimethylhydrazine (DMH) in male Sprague-Dawley (SD) rats as later adults. We also evaluated whether WD reintroduction during adulthood can modify susceptibility to colon carcinogenesis. Pregnant SD rats received one of two diets AIN-93G or WD at gestational day 12 (GD 12). F1 male pups were weaned (21d) and fed the same AIN- 93G or WD diets from their dams until postnatal day 50 (PND 50). At this point, they were given four subcutaneous injections of carcinogen DMH (40 mg/body weight) and were shared the following diets/group: group I (AIN-93/DMH/AIN-93) a lifetime control diet-fed group (GD 12 until postnatal day - PND 370), group II (AIN-93/DMH/WD) received WD only in adulthood (at PND 260), group III (WD/DMH/AIN-93) received WD during pregnancy from dams until prepubertal stage (GD 12 - PND 50) and group IV (WD/DMH/WD), received WD since pregnancy from dams (GD 12) until prepubertal stage (PND 50) and was reintroduced to WD during adulthood (PND 260). All groups were euthanized at the end of 50th week (PND 370). The colon was removed and the aberrant crypt foci (ACF) were stereoscopically and histologically scored for number, distribution and multiplicity. Neoplastic lesions and serum insulin and leptin concentrations were analysed at necropsy. ACF multiplicity and dysplastic lesions were significantly higher in the group fed WD during pregnancy until prepubertal stage (group III) than control group (group I). In the group III, the number of adenocarcinomas were higher than control (group I). In the group fed WD only in adulthood (group II), ACF multiplicity was significantly higher than in the control (group I). The group ... / CNPq: 142195/2010-3 / FAPESP: 10/18827-0

Made available in DSpace on 2015-12-10T14:23:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-28. Added 1 bitstream(s) on 2015-12-10T14:30:04Z : No. of bitstreams: 1 000853903.pdf: 918508 bytes, checksum: d82c80d39357f403a66df5582254910d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O interferon alfa (IFN-α), um IFN do tipo I, se apresenta como uma citocina com grande potencial terapêutico, pois atua no combate direto às células tumorais, além de agir sobre a maturação de células dendríticas (DCs), que são células apresentadoras de antígenos profissionais e peças chave na elaboração da uma resposta antitumoral. Entretanto, a administração sistêmica de citocinas pode produzir toxicidade importante nos pacientes, de modo que a indução de sua produção in situ poderia representar uma forma de imunomodulação mais adequada. Assim, o objetivo deste estudo é verificar a ação de vetores lentivirais carregando o gene do IFN-α para transdução de células tumorais, permitindo assim a produção localizada de IFN-α, a fim de explorar, in vitro, seu potencial lítico e imunomodulatório sobre DCs. Vetores lentivirais carregando o gene do IFN-α humano (Lego-IFN) ou GFP (Lego-GFP) foram utilizados para a transdução in vitro de células de câncer colorretal. A transdução foi feita com diferentes multiplicidades de infecção (MOIs - 0.3, 1.0, 2.0, 4.0) para avaliarmos o efeito dose-dependente, seguido de co-cultura com DCs derivadas de monócitos de doadores saudáveis (DC-0.3, DC-1.0, DC-2.0, DC-4.0). Após 48h de co-cultura, as DCs foram avaliadas fenotípica e funcionalmente, através da análise dos marcadores de membrana por citometria de fluxo, capacidade de aloestimulação e de indução de linfócitos T citotóxicos (CTLs). Nós observamos que a transdução com Lego-GFP, mas não com Lego-IFN, aumentou a imunogenicidade das células tumorais, com aumento de expressão de CD54 e HLA-DR. A co-cultura de DCs com células tumorais transduzidas com Lego-IFN aumentou discretamente seu perfil de ativação, mas não seu potencial aloestimulatório in vitro. Observamos que linfócitos cultivados com DC-2.0 produziram níveis mais altos de IFN-γ, sugerindo a indução de um perfil Th1, enquanto que... / Interferon alpha (IFN-α) is a type I IFN with great therapeutic potential, since it is able to directly fight tumor cells and enhance the maturation of dendritic cells (DCs), the main antigen-presenting cells, required for an effective antitumor response. However, the systemic administration of cytokines can induce severe collateral effects. Therefore, the induction of cytokine secretion in situ should represent a more adequate approach for cytokine-based immunotherapy. Thus, the goal of this study was to induce IFN-α secretion by colon cancer cells by transduction with a lentivirus vector carrying the human IFN-α gene, followed by analysis of its immunomodulatory potential over DCs. Transduction was made with different multiplicities of infection (MOIs - 0.3, 1.0, 2.0 and 4.0) to evaluate the dose-dependent effects. Such cells were co-cultured with monocyte-derived DCs from healthy donors (DC-0.3, DC-1.0, DC-2.0 and DC-4.0). Forty-eight hours later, DCs were evaluated for their phenotype (surface activation/maturation markers) by flow cytometry, their ability to induce allogeneic response in a mixed leukocyte reaction (MLR) and effectiveness to induce cytotoxic T cells. We observed that transduction with Lego-GFP, but not Lego-IFN, increased tumor cells' immunogenicity with up-regulation of the markers CD54 and HLA-DR. Co-culture of Lego-IFN-transduced tumor cells with DCs slightly enhanced their activation phenotype but not their potential to stimulate T cell proliferation in vitro. Furthermore, we observed that lymphocytes cultured with DC-2.0 produced higher levels of IFN-γ, suggesting an induction of Th1 profile on T cells, while DC-GFP induced more IL-10 and IL-4. Additionally, DC-4.0 was more efficient in generating cytotoxic T lymphocytes (CTLs) that the control DC, however DC-GFP induced even more CD8+T cell proliferation. The enhancement of tumor cell immunogenicity and the superior induction of CLTs ...

Made available in DSpace on 2014-06-11T19:27:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-21Bitstream added on 2014-06-13T20:17:31Z : No. of bitstreams: 1 fragoso_mf_me_botfm.pdf: 663141 bytes, checksum: 3faf3707c9cd0b2583b7df103e5d313a (MD5) / Açaí, fruto da Euterpe oleraceae Martius, é consumido in natura e em uma variedade de bebidas e alimentos. Esse fruto tem sido bastante consumido e produzido no Brazil, devido à alta popularidade como alimento funcional com capacidade antioxidante e antiinflamatória. Este trabalho investigou o efeito protetor potencial do consumo da polpa de açaí (PA) seca por pulverização na carcinogênese de cólon induzida pela 1,2-dimetilhidrazina (DMH) em ratos Wistar adultos (peso médio de 200g). Após 4 semanas de administração de DMH, os grupos passaram a receber dieta padrão, dieta contendo 2.5% ou 5.0% de PA e 0.2% de N-acetilcisteína (NAC) durante 10 semanas de tratamento para análise de focos de criptas aberrantes (FCA). Adicionalmente, dois grupos receberam dieta padrão e dieta contendo 5.0% de PA durante 20 semanas de tratamento para análise de tumores de cólon. No experimento de 14 semanas, foi observada redução significante no número de criptas aberrantes (CA) e em FCA (1-3 CA) nos grupos que receberam 5.0% de PA e 0.2% de NAC (37% e 47% de inibição, p = 0.036; 37% e 41% de inibição, p = 0.042), respectivamente, quando comparados ao grupo não tratado. No experimento de 24 semanas, foi observada redução no número de adenocarcinomas invasivos e multiplicidade de tumores no grupo que recebeu 5.0% de PA na dieta (p < 0.005 e p = 0.001, respectivamente) quando comparados ao grupo não tratado. Além disso, redução significante na proliferação celular de tumores marcados com Ki-67 e na taxa de crescimento tumoral foi observada no grupo que recebeu 5.0% de PA (p = 0.003 e p = 0.001). Portanto, os resultados desse trabalho indicam que uma dieta acrescida de 5.0% da polpa de açaí seca por pulverização pode reduzir o desenvolvimento de FCA e de tumores de colón induzidos em ratos, indicando seu uso como um potencial alimento funcional / Acai, fruit from Euterpe oleraceae Martius, is consumed in natura and in a variety of beverages and food preparations. This fruit has been widely consumed and produced in Brazil, due to the high popularity as a functional food with antioxidant and anti-inflammatory capacities. This study investigated the potential protective effect of spray-dried açai pulp (AP) intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male adult Wistar rats (mean weight of 200g). After 4 weeks of DMH administration, groups were fed standard diet, diet containing AP at 2.5% or 5.0% or 0.2% N-acetylcysteine (NAC) during 10 weeks for analysis of aberrant crypt foci (ACF) as endpoint. Additionally, two groups were fed standard diet or diet containing AP at 5.0% during 20 weeks for analysis of colon tumor as endpoint. In 14-week ACF assay, a significant reduction in number of aberrant crypt (AC) and in ACF (1-3 AC) were observed in groups fed 5.0% AP and 0.2% NAC (37% and 47% inhibition, p = 0.036; 37% and 41% inhibition, p = 0.042), respectively, when compared to the untreated group. In 24-week tumor assay, a significant reduction in number of invasive adenocarcinomas and tumor multiplicity were observed in group fed 5.0% AP (p < 0.005 and p = 0.001, respectively) when compared to untreated group. Also, significant reduction in tumor Ki-67 cell proliferation and growth index was observed in group fed 5.0% AP (p = 0.003 and p = 0.001). Therefore, the findings of this study indicate that spray-dried açai pulp feeding at 5.0% may reduce the development of chemically-induced ACF and colon tumor in male rats, indicating their use as a potential functional food

Made available in DSpace on 2014-06-11T19:23:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T20:10:15Z : No. of bitstreams: 1 moura_na_me_botib.pdf: 645966 bytes, checksum: 470176f1b4d022fe7693f78122d3d799 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Yacon (Smallanthus sonchifolius) é uma raiz originária da região dos Andes que tem se destacado pelos seus compostos bioativos principalmente frutanos como futooligossacarídeos e inulina. O presente projeto teve como objetivo determinar a atividade quimioprotetora da ingestão de Yacon sobre o desenvolvimento de lesões pré-neoplásicas (focos de criptas aberrantes-FCA) induzidas pela dimetilhidrazina (DMH) em ratos Wistar machos. Os animais foram divididos em seis grupos com 5 a 12 animais cada. Os animais dos Grupos 1 a 4 e Grupos 5 e 6 receberam respectivamente, quatro injeções subcutâneas de DMH (40 mg/Kg) e solução de EDTA (veículo da DMH) nas duas semanas iniciais do experimento respectivamente. Os animais receberam ração basal até a sexta semana do experimento e a partir desta os animais dos grupos 2, 3, 4, 5 receberam ração acrescida de extrato de Yacon a 0,5%, 1%, 1% e 1%, respectivamente. Os animais do grupo 4 receberam Lactobacilus casei (2,5 x 1010 de UFC por Kg de ração). O sacrifício ocorreu na vigésima semana de experimento para análise de focos de criptas aberrantes (FCA) e tumores. Nossos resultados mostraram uma redução no número, multiplicidade de FCA e no número de adenocarcinomas invasivos nos grupos tratados com 1% yacon (G3) e na combinação simbiótica (G4), (0,05 < p < 0, 001). A multiplicidade de tumores (invasivos e não invasivos) foi significativamente menor no grupo tratado com a combinação simbiótica (p < 0,02). Observou-se também uma redução significativa nas taxas de proliferação celular tanto em criptas colônicas como em tumores nos grupos tratados com 1% yacon (G3) e na combinação simbiótica (G4), p < 0.001. Os resultados sugerem que a ingestão de extrato de yacon exerce atividade quimiopreventiva contra carcinogênese de cólon / Yacon (Smallanthus sonchifolius) is a tuberous root native to the Andean region of South America which contains high amounts of inulin-type fructans. The present study investigated the beneficial potential of yacon root intake on development of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. Six groups were studied: Groups 1–4 were given four s.c. injections of DMH (40 mg/kg b.w.) twice a week, during two weeks, whereas Groups 4 and 5 received similar injections of EDTA solution (DMH vehicle). After 6 weeks of DMH-initiation, groups were fed with basal diet (G1 and G6) or basal diet containing dried extract of yacon root at 0.5% (G2), 1.0% (G3 and G5) or a synbiotic formulation (G4) (1.0% yacon root plus Lactobacillus casei at 2.5 x 1010 CFU per g diet) for 13 weeks. At 20 week, all animals were killed and the colons were analyzed for development of aberrant crypt foci (ACF) and tumor. A significant reduction in number and multiplicity of ACF and in number of invasive adenocarcinomas was observed in the groups orally treated with 1.0% yacon root (G3) or their synbiotic formulation (G4) (0.05 < p < 0.001). Tumor multiplicity (noninvasive plus invasive) was significantly lower solely in group fed with symbiotic formulation (p < 0.02). Also, a reduction in cell proliferation indexes in colonic crypt and tumor were observed in groups orally treated with 1.0% yacon root (G3) or their synbiotic formulation (G4) (p < 0.001). The findings this study suggest that yacon root intake may have potential as chemopreventive agent against colon carcinogenesis

Orientador: Luis Fernando Barbisan / Banca: Camila Renata Correa / Banca: Sérgio Britto Garcia / Resumo: Açaí, fruto da Euterpe oleraceae Martius, é consumido in natura e em uma variedade de bebidas e alimentos. Esse fruto tem sido bastante consumido e produzido no Brazil, devido à alta popularidade como alimento funcional com capacidade antioxidante e antiinflamatória. Este trabalho investigou o efeito protetor potencial do consumo da polpa de açaí (PA) seca por pulverização na carcinogênese de cólon induzida pela 1,2-dimetilhidrazina (DMH) em ratos Wistar adultos (peso médio de 200g). Após 4 semanas de administração de DMH, os grupos passaram a receber dieta padrão, dieta contendo 2.5% ou 5.0% de PA e 0.2% de N-acetilcisteína (NAC) durante 10 semanas de tratamento para análise de focos de criptas aberrantes (FCA). Adicionalmente, dois grupos receberam dieta padrão e dieta contendo 5.0% de PA durante 20 semanas de tratamento para análise de tumores de cólon. No experimento de 14 semanas, foi observada redução significante no número de criptas aberrantes (CA) e em FCA (1-3 CA) nos grupos que receberam 5.0% de PA e 0.2% de NAC (37% e 47% de inibição, p = 0.036; 37% e 41% de inibição, p = 0.042), respectivamente, quando comparados ao grupo não tratado. No experimento de 24 semanas, foi observada redução no número de adenocarcinomas invasivos e multiplicidade de tumores no grupo que recebeu 5.0% de PA na dieta (p < 0.005 e p = 0.001, respectivamente) quando comparados ao grupo não tratado. Além disso, redução significante na proliferação celular de tumores marcados com Ki-67 e na taxa de crescimento tumoral foi observada no grupo que recebeu 5.0% de PA (p = 0.003 e p = 0.001). Portanto, os resultados desse trabalho indicam que uma dieta acrescida de 5.0% da polpa de açaí seca por pulverização pode reduzir o desenvolvimento de FCA e de tumores de colón induzidos em ratos, indicando seu uso como um potencial alimento funcional / Abstract: Acai, fruit from Euterpe oleraceae Martius, is consumed in natura and in a variety of beverages and food preparations. This fruit has been widely consumed and produced in Brazil, due to the high popularity as a functional food with antioxidant and anti-inflammatory capacities. This study investigated the potential protective effect of spray-dried açai pulp (AP) intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male adult Wistar rats (mean weight of 200g). After 4 weeks of DMH administration, groups were fed standard diet, diet containing AP at 2.5% or 5.0% or 0.2% N-acetylcysteine (NAC) during 10 weeks for analysis of aberrant crypt foci (ACF) as endpoint. Additionally, two groups were fed standard diet or diet containing AP at 5.0% during 20 weeks for analysis of colon tumor as endpoint. In 14-week ACF assay, a significant reduction in number of aberrant crypt (AC) and in ACF (1-3 AC) were observed in groups fed 5.0% AP and 0.2% NAC (37% and 47% inhibition, p = 0.036; 37% and 41% inhibition, p = 0.042), respectively, when compared to the untreated group. In 24-week tumor assay, a significant reduction in number of invasive adenocarcinomas and tumor multiplicity were observed in group fed 5.0% AP (p < 0.005 and p = 0.001, respectively) when compared to untreated group. Also, significant reduction in tumor Ki-67 cell proliferation and growth index was observed in group fed 5.0% AP (p = 0.003 and p = 0.001). Therefore, the findings of this study indicate that spray-dried açai pulp feeding at 5.0% may reduce the development of chemically-induced ACF and colon tumor in male rats, indicating their use as a potential functional food / Mestre