RESUMO
MicroRNAs (miRNAs) are post-transcriptional gene expression regulators which expression is frequently altered in hepatocellular carcinoma (HCC). ß-ionone (ßI) is noted for its ability to inhibit persistent preneoplastic lesions (pPNLs) in liver rats. We evaluated the expression of miRNAs involved in carcinogenesis and possible targets modulated by ßI, in pPNLs and surrounding of microdissected tissues. Rats subjected to resistant hepatocyte model were treated during promotion stage with ßI (16 mg/100 g body weight) or corn oil (CO; 0.25 mL/100 g body weight; controls). Five animals receive no treatment (NT). In CO group, 38 and 29 miRNAs showed reduced expression relative to NT (P < 0.05) in pPNLs and surrounding, respectively. No miRNAs showed increased expression in surrounding of the CO compared to NT group; however, 30 miRNAs showed increased expression (P ≤ 0.05) in pPNLs of the CO group. There was no difference between ßI and CO groups (P > 0.05) in the expression of miRNAs in surrounding. In pPNLs ßI increased expression of miR-122 and miR-34a (P ≤ 0.05) and reduced of Igf2 (P ≤ 0.05), target of the latter, compared to CO. Additionally, ßI decreased the expression of miR-181c and its target Gdf2 (P ≤ 0.05). ßI reduced the expression of miR-181b and miR-708 (P ≤ 0.05) and increased the expression of their respective target mRNAs Timp3 and Mtss1 (P ≤ 0.05), relative to CO group. Modulation of miRNAs target genes by ßI was confirmed in vitro. ßI is a promising chemopreventive agent in the initial stages of hepatocarcinogenesis, as it modulates the expression of the miRNAs and target genes that can alter the metastatic phenotype of HCC. © 2016 Wiley Periodicals, Inc.
Assuntos
Anticarcinógenos/uso terapêutico , Carcinoma Hepatocelular/prevenção & controle , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hepáticas/prevenção & controle , Fígado/efeitos dos fármacos , MicroRNAs/genética , Norisoprenoides/uso terapêutico , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/prevenção & controle , Ratos , Ratos WistarRESUMO
BACKGROUND: Although males contribute half of the embryo's genome, only recently has interest begun to be directed toward the potential impact of paternal experiences on the health of offspring. While there is evidence that paternal malnutrition may increase offspring susceptibility to metabolic diseases, the influence of paternal factors on a daughter's breast cancer risk has been examined in few studies. METHODS: Male Sprague-Dawley rats were fed, before and during puberty, either a lard-based (high in saturated fats) or a corn oil-based (high in n-6 polyunsaturated fats) high-fat diet (60 % of fat-derived energy). Control animals were fed an AIN-93G control diet (16 % of fat-derived energy). Their 50-day-old female offspring fed only a commercial diet were subjected to the classical model of mammary carcinogenesis based on 7,12-dimethylbenz[a]anthracene initiation, and mammary tumor development was evaluated. Sperm cells and mammary gland tissue were subjected to cellular and molecular analysis. RESULTS: Compared with female offspring of control diet-fed male rats, offspring of lard-fed male rats did not differ in tumor latency, growth, or multiplicity. However, female offspring of lard-fed male rats had increased elongation of the mammary epithelial tree, number of terminal end buds, and tumor incidence compared with both female offspring of control diet-fed and corn oil-fed male rats. Compared with female offspring of control diet-fed male rats, female offspring of corn oil-fed male rats showed decreased tumor growth but no difference regarding tumor incidence, latency, or multiplicity. Additionally, female offspring of corn oil-fed male rats had longer tumor latency as well as decreased tumor growth and multiplicity compared with female offspring of lard-fed male rats. Paternal consumption of animal- or plant-based high-fat diets elicited opposing effects, with lard rich in saturated fatty acids increasing breast cancer risk in offspring and corn oil rich in n-6 polyunsaturated fatty acids decreasing it. These effects could be linked to alterations in microRNA expression in fathers' sperm and their daughters' mammary glands, and to modifications in breast cancer-related protein expression in this tissue. CONCLUSIONS: Our findings highlight the importance of paternal nutrition in affecting future generations' risk of developing breast cancer.
Assuntos
Neoplasias da Mama/etiologia , Exposição Paterna , Efeitos Tardios da Exposição Pré-Natal , Animais , Apoptose , Neoplasias da Mama/patologia , Proliferação de Células , Transformação Celular Neoplásica , Análise por Conglomerados , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Lipídeos/química , Masculino , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais , Neoplasias Mamárias Experimentais , Carne , MicroRNAs , Plantas/química , Gravidez , Proteômica/métodos , Ratos , Espermatozoides/metabolismoRESUMO
Breast cancer is a global public health problem and accumulating evidence indicates early-life exposures as relevant factors in the disease risk determination. Recent studies have shown that paternal nutrition can influence offspring health including breast cancer risk. Selenium is a micronutrient with essential role in central aspects of embryogenesis, male fertility and cancer and that has been extensively studied as a chemopreventive agent in several breast cancer experimental models. Thus, we designed an animal study to evaluate whether paternal selenium deficiency or supplementation during preconception could affect the female offspring mammary gland development and breast cancer susceptibility. Male Sprague-Dawley rats were fed AIN93-G diet containing 0.15 ppm (control diet), 0.05 ppm (deficient diet) or 1 ppm (supplemented diet) of selenium for 9 weeks and mated with control female rats. Mammary carcinogenesis was induced with 7,12-dimethylbenz[a]anthracene (DMBA) in their female offspring. Paternal selenium deficiency increased the number of terminal end buds, epithelial elongation and cell proliferation in the mammary gland of the female rat offspring and these effects were associated with higher susceptibility to DMBA-induced mammary tumors (increased incidence and higher grade tumors). On the other hand, paternal selenium supplementation did not influence any of these parameters. These results highlight the importance of father's nutrition including selenium status as a relevant factor affecting daughter's breast cancer risk and paternal preconception as a potential developmental stage to start disease preventive strategies.
Assuntos
Neoplasias Mamárias Experimentais/etiologia , Selênio/administração & dosagem , Selênio/deficiência , 9,10-Dimetil-1,2-benzantraceno , Animais , Carcinogênese , Suplementos Nutricionais , Feminino , Masculino , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Ratos , Ratos Sprague-DawleyRESUMO
The risk of recurrence of estrogen receptor-positive breast cancer remains constant, even 20 years after diagnosis. Recurrence may be more likely in patients pre-programmed for it already in the womb, such as in the daughters born to obese mothers. Maternal obesity persistently alters offspring's gut microbiota and impairs tumor immune responses. To investigate if the gut dysbiosis is linked to increased risk of mammary cancer recurrence in the offspring of obese rat dams, we fed adult offspring genistein which is known to have beneficial effects on the gut bacteria. However, the effects of genistein on breast cancer remain controversial. We found that genistein intake after tamoxifen response prevented the increased risk of local recurrence in the offspring of obese dams but had no effect on the control offspring. A significant increase in the abundance of inflammatory Prevotellaceae and Enterobacteriaceae, and a reduction in short-chain fatty acid producing Clostridiaceae was observed in the offspring of obese dams. Genistein supplementation reversed these changes as well as reversed increased gut metabolite N-acetylvaline levels which are linked to increased all-cause mortality. Genistein supplementation also reduced genotoxic tyramine levels, increased metabolites improving pro-resolving phase of inflammation, and reversed the elevated tumor mRNA expression of multiple immunosuppressive genes in the offspring of obese dams. If translatable to breast cancer patients, attempts to prevent breast cancer recurrences might need to focus on dietary modifications which beneficially modify the gut microbiota.
Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Genisteína/farmacologia , Neoplasias Mamárias Animais/microbiologia , Obesidade/microbiologia , Efeitos Tardios da Exposição Pré-Natal/microbiologia , Animais , Feminino , Neoplasias Mamárias Animais/tratamento farmacológico , Obesidade/etiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Ratos , Ratos Sprague-DawleyRESUMO
Zinc is required for fetal development and is involved in key processes associated with breast carcinogenesis. We evaluated whether maternal zinc deficiency or supplementation during gestation influences female offspring susceptibility to breast cancer in adulthood. C57BL/6 mice consumed during gestation control (30â¯p.p.m. zinc), zinc-deficient (8 p.p.m) or zinc-supplemented (45â¯p.p.m.) diets. Maternal zinc supplementation increased in female mice offspring the incidence of chemically-induced mammary adenocarcinomas that were heavier, compared to control group. This was accompanied by a decreased number of terminal end buds, increased cell proliferation and apoptosis, and increased tumor suppressors p21, p53 and Rassf1, Zfp382 and Stat3 expression in mammary glands, as well as increased zinc status. Although maternal zinc deficiency did not alter the incidence of these lesions, it also induced heavier mammary adenocarcinomas, compared to control group. These effects were accompanied by a decreased number of terminal end buds, increased proto-oncogenes c-Myc and Lmo4 expression and H3K9Me3 and H4K20Me3 epigenetic marks in mammary glands of offspring, and decreased zinc status and increased levels of oxidative marker malondialdehyde. The data suggest that both maternal zinc deficiency and supplementation during gestation programmed increased breast cancer susceptibility in adult mice offspring following a J-shaped pattern through distinct mechanisms.
Assuntos
Deficiências Nutricionais/complicações , Suplementos Nutricionais , Neoplasias Mamárias Experimentais/etiologia , Zinco/administração & dosagem , Zinco/deficiência , Animais , Apoptose , Proliferação de Células , Feminino , Perfilação da Expressão Gênica , Masculino , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proto-Oncogenes , Proteína Supressora de Tumor p53/metabolismoRESUMO
Objetivo: Identificar os principais critérios e preferências na tomada de decisão em saúde para osteoporose pós-menopausa, por três grupos de stakeholders (n=3, cada): médicos; representantes de pacientes; gestores de saúde. Métodos: Uma estrutura de Análise de Decisão Multicritério (MCDA) foi realizada para gerar priorização entre tecnologias: uma revisão da literatura formou conjuntos de critérios; um painel online validou os critérios selecionados; o método AHP (Analytic Hierarchy Process) atribuiu pesos de importância para cada critério, por consenso. Resultados: Os critérios avaliados foram: eficácia (fraturas clínicas, vertebrais, não vertebrais e de quadril, densidade mineral óssea), segurança (eventos adversos e tolerabilidade), conveniência (adesão e comodidade posológica) e economia (razão de custo-efetividade incremental RCEI, custo por respondedor, impacto orçamentário e custos indiretos). Fraturas clínicas e de quadril apareceram nas primeiras posições para todos os grupos. Para os médicos, fratura de quadril (26,11%) e eventos adversos (14,64%) foram os principais critérios de priorização; para os representantes dos pacientes, fratura clínica (25,09%) e de quadril (22,84%), enquanto critérios econômicos receberam os menores pesos (1,2% a 0,98%), abaixo da comodidade posológica, por exemplo (4%). Gestores públicos priorizaram RCEI (19,44%) e fratura de quadril (16,21%). Conclusões: Os resultados apresentados têm potencial para auxiliar na tomada de decisão e priorização de tratamentos para osteoporose e estão em linha ao observado em estudos de preferência nesta área terapêutica. Embora os pesos finais tenham variado entre os grupos, os desfechos de eficácia que envolvem fraturas foram os critérios priorizados.
Objective: To identify the main criteria and preferences in healthcare decision-making for postmenopausal osteoporosis according to three stakeholder groups (n=3, each): physicians, patient representatives, and public healthcare managers. Methods: A multi-Criteria Decision Analysis framework was performed to generate prioritization rankings between technologies: a literature review formed sets of criteria; an online panel validated the pre-selected criteria; the Analytic Hierarchy Process (AHP) method assigned importance weights to each criterion by consensus. Results: The final weighted average included: efficacy (clinical fractures, new vertebral, non-vertebral, hip fractures, and bone mineral density), safety (clinically significant adverse events and tolerability), convenience (adherence and dosing convenience), and economics (incremental cost-effectiveness ratio ICER, cost per responder, budget impact and indirect costs). New hip and clinical fractures appeared in the top-five positions for all stakeholder groups. For physicians the main criteria were new hip fracture (26.11%) and adverse events (14.64%); similarly, for patient representatives, clinical fracture (25.09%) and new hip fracture (22.84%) were the most important ones, while economic criteria received the lowest weights (1,2% to 0,98%), below dosing convenience, for example (4%). Public healthcare managers prioritized ICER (19.44%) and new hip fractures (16.21%). Conclusions: The presented results have the potential to assist decision-making and treatment prioritization in postmenopausal osteoporosis. Although final weightings varied among stakeholders, efficacy outcomes involving fractures were the priority criteria for all of them. It is possible to observe similar results in previously published studies of preferences in osteoporosis.
Assuntos
Osteoporose , Teoria da Decisão , Técnicas de Apoio para a DecisãoRESUMO
PURPOSE: Whether it is safe for estrogen receptor-positive (ER+) patients with breast cancer to consume soy isoflavone genistein remains controversial. We compared the effects of genistein intake mimicking either Asian (lifetime) or Caucasian (adulthood) intake patterns to that of starting its intake during tamoxifen therapy using a preclinical model. EXPERIMENTAL DESIGN: Female Sprague-Dawley rats were fed an AIN93G diet supplemented with 0 (control diet) or 500 ppm genistein from postnatal day 15 onward (lifetime genistein). Mammary tumors were induced with 7,12-dimethylbenz(a)anthracene (DMBA), after which a group of control diet-fed rats were switched to genistein diet (adult genistein). When the first tumor in a rat reached 1.4 cm in diameter, tamoxifen was added to the diet and a subset of previously only control diet-fed rats also started genistein intake (post-diagnosis genistein). RESULTS: Lifetime genistein intake reduced de novo resistance to tamoxifen, compared with post-diagnosis genistein groups. Risk of recurrence was lower both in the lifetime and in the adult genistein groups than in the post-diagnosis genistein group. We observed downregulation of unfolded protein response (UPR) and autophagy-related genes (GRP78, IRE1α, ATF4, and Beclin-1) and genes linked to immunosuppression (TGFß and Foxp3) and upregulation of cytotoxic T-cell marker CD8a in the tumors of the lifetime genistein group, compared with controls, post-diagnosis, and/or adult genistein groups. CONCLUSIONS: Genistein intake mimicking Asian consumption patterns improved response of mammary tumors to tamoxifen therapy, and this effect was linked to reduced activity of UPR and prosurvival autophagy signaling and increased antitumor immunity. Clin Cancer Res; 23(3); 814-24. ©2017 AACR.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Moduladores de Receptor Estrogênico/uso terapêutico , Genisteína/farmacologia , Neoplasias Mamárias Experimentais/tratamento farmacológico , Fitoestrógenos/farmacologia , Alimentos de Soja , Tamoxifeno/uso terapêutico , 9,10-Dimetil-1,2-benzantraceno , Animais , Antineoplásicos Hormonais/farmacologia , Autofagia/efeitos dos fármacos , Autofagia/genética , Citocinas/sangue , Dieta , Chaperona BiP do Retículo Endoplasmático , Moduladores de Receptor Estrogênico/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genisteína/administração & dosagem , Genisteína/sangue , Isoflavonas/sangue , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Fitoestrógenos/administração & dosagem , Fitoestrógenos/sangue , Ratos , Ratos Sprague-Dawley , Recidiva , Alimentos de Soja/efeitos adversos , Tamoxifeno/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Resposta a Proteínas não Dobradas/genéticaRESUMO
Objetivo: Estimar a utilização de recursos e os custos médicos diretos associados às fraturas por fragilidade, sob as perspectivas do Sistema Único de Saúde (SUS) e do Sistema de Saúde Suplementar (SSS) no Brasil, por meio de abordagem de microcusteio. Métodos: Para a determinação do padrão de utilização de recursos, foi conduzida uma revisão da literatura sobre o manejo das fraturas por fragilidade (fêmur proximal, terço distal do rádio e vértebra). As condutas foram validadas por dois especialistas. Foram considerados apenas custos diretos, sob as perspectivas do SUS e do SSS como fontes pagadoras, a partir de listas oficiais de preços adequadas a cada categoria de custos e a cada perspectiva. Resultados: Os custos finais médios atribuídos ao tratamento cirúrgico da fratura de fêmur proximal, sob as perspectivas do SUS e do SSS, foram de R$ 5.612,13 e R$ 52.384,06, respectivamente. Para as fraturas do terço distal do rádio, os custos médios por paciente para o tratamento conservador e cirúrgico foram de R$ 661,53 e R$ 1.405,21, respectivamente, sob a perspectiva do SUS, e de R$ 8.917,75 e R$ 21.689,92, para a perspectiva privada. Quanto às fraturas vertebrais, os custos por paciente para o tratamento conservador e cirúrgico foram de R$ 1.165,93 e R$ 9.775,56, respectivamente, no cenário do SUS, e de R$ 15.053,32 e R$ 54.596,78, respectivamente, sob a perspectiva do SSS. Conclusões: No Brasil, custos diretos das fraturas por fragilidade são relevantes, justificando a preocupação não apenas clínica, mas também econômica para fontes pagadoras e sociedade
Objective: To estimate the resources utilization, and direct medical costs associated with fragility fractures, from the perspectives of the Unified Healthcare System (SUS) and Supplementary Healthcare System (SSS) in Brazil, through a microcosting approach. Methods: A literature review was conducted regarding the management of fragility fractures (proximal femur, distal radius third of the radius and vertebra) to determine the pattern of resource utilization. The methods were validated by two experts. Only direct costs were considered, from the perspectives of SUS and SSS as paying sources, based on official price lists appropriate to each cost category and perspective. Public bid databases provide the actual market prices for the SUS perspective. Results: The average final costs attributed to the surgical treatment of the proximal femur fractures from the perspectives of SUS and SSS were BRL 5,612.13 and BRL 52,384.06, respectively. For fractures of the distal radius, the average costs per patient for conservative and surgical treatment were BRL 661.53 and BRL 1,405.21, respectively, from the SUS perspective, and BRL 8,917.75 and BRL 21,689.92, from the private perspective. For vertebral fractures, the cost per patient for conservative and surgical treatment were BRL 1.165,93 and BRL 9.775,56, respectively, in the SUS scenario and BRL 15.053,32 and BRL 54.596,78, respectively, under the SSS perspective. Conclusions: In Brazil, direct costs of fragility fractures are substantial, justifying not only clinical but also economic concerns for payers and society
Assuntos
Osteoporose , Custos e Análise de Custo , Fraturas Ósseas , Fraturas por OsteoporoseRESUMO
The present study investigated whether early life exposure to high levels of animal fat increases breast cancer risk in adulthood in rats. Dams consumed a lard-based high-fat (HF) diet (60% fat-derived energy) or an AIN93G control diet (16% fat-derived energy) during gestation or gestation and lactation. Their 7-week-old female offspring were exposed to 7,12-dimethyl-benzo[a]anthracene to induce mammary tumors. Pregnant dams consuming an HF diet had higher circulating leptin levels than pregnant control dams. However, compared to the control offspring, significantly lower susceptibility to mammary cancer development was observed in the offspring of dams fed an HF diet during pregnancy (lower tumor incidence, multiplicity and weight), or pregnancy and lactation (lower tumor multiplicity only). Mammary epithelial elongation, cell proliferation (Ki67) and expression of NFκB p65 were significantly lower and p21 expression and global H3K9me3 levels were higher in the mammary glands of rats exposed to an HF lard diet in utero. They also tended to have lower Rank/Rankl ratios (P=.09) and serum progesterone levels (P=.07) than control offspring. In the mammary glands of offspring of dams consuming an HF diet during both pregnancy and lactation, the number of terminal end buds, epithelial elongation and the BCL-2/BAX ratio were significantly lower and serum leptin levels were higher than in the controls. Our data confirm that the breast cancer risk of offspring can be programmed by maternal dietary intake. However, contrary to our expectation, exposure to high levels of lard during early life decreased later susceptibility to breast cancer.
Assuntos
Neoplasias da Mama/prevenção & controle , Dieta Hiperlipídica/efeitos adversos , Desenvolvimento Fetal , Lactação , Glândulas Mamárias Animais/patologia , Fenômenos Fisiológicos da Nutrição Materna , 9,10-Dimetil-1,2-benzantraceno , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/uso terapêutico , Resistência à Doença , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Estimativa de Kaplan-Meier , Leptina/agonistas , Leptina/sangue , Glândulas Mamárias Animais/metabolismo , Gravidez , Progesterona/antagonistas & inibidores , Progesterona/sangue , Ratos Sprague-Dawley , Carga TumoralRESUMO
Avaliações econômicas em saúde são essenciais para a tomada de decisão de gestores, visto que as inovações no setor nem sempre podem ser incorporadas conforme as expectativas dos usuários e da indústria. Logo, a análise de impacto orçamentário (AIO), uma das principais ferramentas da avaliação de tecnologias em saúde (ATS), permite aos gestores estimar o potencial número de indivíduos elegíveis para determinada tecnologia ao longo dos anos, prever quanto será necessário gastar para incorporar a tecnologia ou, eventualmente, se haverá economia nos cofres do pagador com a inclusão dela. Com a crescente publicação de artigos científicos sobre AIO no Brasil, surge a preocupação a respeito da qualidade metodológica desses estudos. O objetivo desta revisão é apresentar recomendações-chave para a elaboração de uma AIO adequada e expor a utilidade prática da AIO para a tomada de decisão de gestores de saúde por meio da análise de quatro estudos publicados. O formato de apresentação de uma AIO possibilita rápido entendimento e possui atributos que permitem evidenciar o maior valor de produtos e serviços de saúde junto aos tomadores de decisão em saúde, contribuindo para as melhores escolhas do ponto de vista clínico e econômico, nos sistemas público e privado. Porém, cabe ressaltar que alguns estudos ainda carecem de evidências de mundo real ou dados epidemiológicos para as estimativas e trabalham de maneira insuficiente as ferramentas para a redução de incertezas paramétricas.
Health economics evaluations are essential for decision makers, since innovations can not always be incorporated according to expectations of users and industry. Therefore, the Budget Impact Analysis (BIA), one of the main tools in Health Technology Assessment (HTA), allows managers to estimate the potential number of individuals eligible for a given technology over the years, to predict how much it will be necessary to spend for incorporate the technology or, eventually, whether there will be savings in the payer's coffers with the inclusion of the same. With the growing publication of scientific articles on BIA in Brazil, there is concern about the methodological quality of these studies. The objective of this review is to present key recommendations to elaborate an adequate BIA, commenting on four published studies, aiming to expose the practical utility of BIA for health managers. The presentation format of the BIA provides a quick understanding and has attributes that allows evidence of the highest value of health products and services among health decision makers, contributing to the best clinical and economic choices in public and private health systems. However, it should be noted in some studies there is still a lack of real-world evidence or epidemiological data for the estimates and insufficient using of tools to reduce parametric uncertainties.
Assuntos
Humanos , Gestão em Saúde , Avaliação da Tecnologia BiomédicaRESUMO
Fatores dietéticos como o selênio (Se) são apontados como importantes moduladores do risco de desenvolvimento do câncer de mama. Essa neoplasia pode apresentar sua origem no início do desenvolvimento e, assim, a alimentação materna poderia ter importantes repercussões na programação fetal da doença. A fim de verificar se diferentes concentração de selênio na dieta materna poderiam programar o risco da progênie feminina ao câncer de mama, ratas foram alimentadas com ração contendo 0,15 (CO), 1,0 (SUP) ou 0,05 (DEF) ppm de Se durante a gestação e sua progênie feminina iniciada com DMBA. A progênie do grupo SUP apresentou menor suscetibilidade à carcinogênese, indicado pelo menor número médio e multiplicidade de adenocarcinomas mamários (p< 0,05), enquanto a do grupo DEF apresentou maior suscetibilidade à carcinogênese, indicado pela maior incidência dos mesmos (p< 0,05). Mães do grupo DEF apresentaram menor concentração de Se no sangue (p< 0,05) e sua prole apresentou menor atividade da enzima GPx1 (p< 0,05). Além disso, observou-se na glândula mamária da progênie de 50 dias menor expressão (western blot e qPCR) de ERα, Her-2, EGFR e Ras no grupo SUP em comparação aos grupos CO e DEF (p< 0,05). Analisou-se, ainda, o padrão de metilação global do DNA (HPLC-DAD), expressão das enzimas DNMT1, 3a e 3b (qPCR), o padrão global de modificações pós traducionais em histonas (western blot) e o padrão de metilação da região promotora do gene Erα (modificação com bissulfito e pirossequenciamento) na glândula mamária da progênie de 50 dias. Não houve diferença no padrão de metilação global do DNA e expressão das enzimas DNMTs (p>0,05). Houve aumento na expressão de H4K16 acetilada nos grupos SUP e DEF (p< 0,05). Finalmente, em comparação a progênie do grupo DEF, a do grupo SUP apresentou região promotora de Erα com aumento marginal (p=0,07) na metilação de dois dinucleotídeos CpG. Conclui-se que o consumo de diferentes concentrações de Se na dieta materna tem impacto sobre a suscetibilidade da progênie ao câncer de mama na vida adulta através da modulação da expressão de receptores e oncogenes relacionados ao desenvolvimeto dessa neoplasia, além da influência em processos epigenéticos. Tais resultados apontam para a existência de uma "janela de programação" no início do desenvolvimento sensível a ação do Se, resultando em diminuição do risco de câncer de mama quando suplementado na dieta materna e o inverso quando de sua deficiencia
Based on epidemiological studies and animal models, the essential micronutrient selenium has been highlighted as a promising dietary factor associated to breast cancer risk reduction. Breast cancer may have its origin in early development and thus the maternal diet could have important implications in the fetal programming of the disease. In order to ascertain whether differences in selenium concentration in maternal diet could modulate the susceptibility of female offspring to breast cancer, a biological assay was conducted in which female rats were fed a diet with 0.15 (CO), 1.0 (SUP) or 0.05 (DEF) ppm of selenium during gestational period and the female offspring subjected to a mammary carcinogenesis model induced by DMBA. SUP group offspring presented decreased susceptibility to mammary carcinogenesis, as indicated by lower (p< 0,05) average number and multiplicity od adenocarcinomas, while the DEF group offspring had a greater susceptibility, as indicated by the increase (p< 0,05) in adenocarcinomas incidency. Mothers of the DEF group pesented lower (p< 0,05) Se blood concetrations and their offspring presented lower (p<0,05).GPx1 activity. In addition, there was a decrease (p< 0,05) in ERα, Her-2, EGFR and Ras expression (western blot and qPCR) in the mammary gland of 7 weeks old female SUP group offspring when compared to CO and DEF groups offspring. DNA global methylation pattern (HPLC-DAD), DNMT1, 3a e 3b expression (qPCR), global pattern of post-translational modification in histones (western blot) and methylation status of Erα promoter region (bisulfite modification and pyrosequencing) were also evaluated in the mammary gland of 7 weeks old offspring. There was no diffrence (p>0,05) in DNA global methylation pattern and DNMTs expression. There was an increase in acetilated H4K16 expression in groups SUP and DEF (p< 0,05). Lastly, when compared to DEF offspring, the SUP offspring presented a marginal increase in the methylation of two CpG dinucleotides in the Erα promoter region. In conclusion, the consumption of different selenium concentration in maternal diet plays a role in the progeny's breast cancer susceptibility through the modulation of receptors and oncogenes expression, in addition to modifications in epigenetic patterns. These results indicate the presence of a "programming window" in the beggining of development susceptible to selenium effects, resulting in decreased breast cancer risk when supplemented and the opposite when deficient