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1.
J Glob Health ; 13: 04127, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37856736

RESUMO

Background: Given the increased risk of malnutrition in children with cleft lip and/or palate (CLP), determining their nutritional status is critical for preventing adverse surgical risks. However, no such disaggregated, national-level data are available in Indonesia. We aimed to determine the nutritional status of patients with clefts in Indonesia and to identify problems and solutions for malnutrition cases within the population. Methods: In this cross-sectional study, we considered records of individuals who underwent primary surgery for CLP in Smile Train-sponsored facilities in Indonesia between 1 January 2016 and 31 December 2021 (n = 18 480). We only included children under the age of five with an evaluation date prior to admission date and excluded subjects with invalid data values. We classified their nutritional status by z-scores according to the World Health Organization Child Growth Standard (2006). Malnutrition cases cover four indicators - stunting, wasting, underweight, and overweight. We compared the prevalence for malnutrition cases in children under the age of five using national health survey data. Results: We included 1899 records following data validation. The national prevalence of stunting (24.4%), wasting (12.5%), and overweight cases (12.9%) was high, while underweight cases (6.8%) were comparatively low. Statistical analyses showed significant differences in nutritional status based on length/height-for-age between girls and boys aged 0-5 months (P = 0.008) and 48-60 months (P = 0.001), and based on body mass index-for-age (P = 0.000) between girls and boys aged 0-5 months. Girls in different age groups exhibited a statistically significant difference in nutritional status based on length/height-for-age (P = 0.002) and weight-for-age (P = 0.017). Concurrent stunting and overweight were the most common forms of concurrent malnutrition (8.7%). We found a significant difference in the prevalence of underweight (P = 0.001) and overweight (P = 0.000) cases between children with CLP and those without CLP. Conclusions: Our findings highlight the importance of nutritional interventions for children with orofacial clefts in Indonesia, and the importance of age and gender in their design and implementation. Further investigation is necessary to explore the risks of overweight and concurrent malnutrition among this population.


Assuntos
Fenda Labial , Fissura Palatina , Desnutrição , Masculino , Feminino , Humanos , Criança , Lactente , Recém-Nascido , Estado Nutricional , Peso Corporal , Fenda Labial/epidemiologia , Fenda Labial/cirurgia , Sobrepeso/epidemiologia , Magreza/epidemiologia , Indonésia/epidemiologia , Estudos Transversais , Fissura Palatina/epidemiologia , Fissura Palatina/cirurgia , Desnutrição/epidemiologia , Transtornos do Crescimento/epidemiologia , Prevalência
2.
J Glob Health ; 12: 04012, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35265326

RESUMO

Background: Orofacial clefts are common birth defects, affecting one newborn in every 700 live births globally. The condition requires prompt identification, feeding support, and timely surgery. While orofacial clefts benefit from a comprehensive, life-long care management in high-income countries, care provision is often lacking or inadequate in poor-resource settings. Data on the burden of orofacial clefts in children born in limited-resource settings remain scarce. The objective of this study was to estimate the prevalence of malnutrition in children using cleft surgery records collected by one large non-governmental cleft organization in low- and middle-income countries (LMICs). Methods: The data set included clinical records of children ≤5 years who underwent primary cleft surgery between 2008 and 2018 in health care facilities across LMICs. Patients' data included birth date, sex, weight at surgery, ethnicity, country of origin, and date of primary surgery and were analysed using descriptive statistics. The prevalence of malnutrition was estimated using weight-for-age z scores and the distribution described in relation to cleft type, sex, ethnic groups, and geography. Comparisons with prevalence estimates for underweight in children under-5 within countries were conducted using publicly available survey data. Results: The analysis included 602 568 children. The prevalence of underweight in children with cleft varies with the epidemiology of cleft and the timing of primary surgery, and between ethnic groups and settings. The overall prevalence of underweight at the time of primary cleft surgery was 28.6% - a figure well above the global underweight prevalence in children under-5 without cleft estimated at 13.5%. We found a positive correlation between the prevalence of underweight among children with cleft and the prevalence of underweight in the DHS program (rs = 0.6305; P < 0.0001). Within-country comparisons showed that, with only few exceptions, the prevalence of underweight was higher in children with clefts than in their peers born without clefts (P < 0.05). Conclusions: Although orofacial cleft is not considered to be a life-threatening condition, our findings show a high burden of malnutrition among patients accessing surgeries in LMICs. Interventions prompting early identification and appropriate feeding management of this group of vulnerable children is essential to leave no one behind in the fight against malnutrition.


Assuntos
Fenda Labial , Fissura Palatina , Desnutrição , Criança , Fenda Labial/epidemiologia , Fenda Labial/cirurgia , Fissura Palatina/epidemiologia , Fissura Palatina/cirurgia , Estudos Transversais , Humanos , Recém-Nascido , Desnutrição/epidemiologia , Prevalência
3.
Cancer Res ; 74(3): 896-907, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24285724

RESUMO

Targeted therapies have yet to have significant impact on the survival of patients with bladder cancer. In this study, we focused on the urea cycle enzyme argininosuccinate synthetase 1 (ASS1) as a therapeutic target in bladder cancer, based on our discovery of the prognostic and functional import of ASS1 in this setting. ASS1 expression status in bladder tumors from 183 Caucasian and 295 Asian patients was analyzed, along with its hypothesized prognostic impact and association with clinicopathologic features, including tumor size and invasion. Furthermore, the genetics, biology, and therapeutic implications of ASS1 loss were investigated in urothelial cancer cells. We detected ASS1 negativity in 40% of bladder cancers, in which multivariate analysis indicated worse disease-specific and metastasis-free survival. ASS1 loss secondary to epigenetic silencing was accompanied by increased tumor cell proliferation and invasion, consistent with a tumor-suppressor role for ASS1. In developing a treatment approach, we identified a novel targeted antimetabolite strategy to exploit arginine deprivation with pegylated arginine deiminase (ADI-PEG20) as a therapeutic. ADI-PEG20 was synthetically lethal in ASS1-methylated bladder cells and its exposure was associated with a marked reduction in intracellular levels of thymidine, due to suppression of both uptake and de novo synthesis. We found that thymidine uptake correlated with thymidine kinase-1 protein levels and that thymidine levels were imageable with [(18)F]-fluoro-L-thymidine (FLT)-positron emission tomography (PET). In contrast, inhibition of de novo synthesis was linked to decreased expression of thymidylate synthase and dihydrofolate reductase. Notably, inhibition of de novo synthesis was associated with potentiation of ADI-PEG20 activity by the antifolate drug pemetrexed. Taken together, our findings argue that arginine deprivation combined with antifolates warrants clinical investigation in ASS1-negative urothelial and related cancers, using FLT-PET as an early surrogate marker of response.


Assuntos
Argininossuccinato Sintase/metabolismo , Tomografia por Emissão de Pósitrons , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Argininossuccinato Sintase/deficiência , Argininossuccinato Sintase/genética , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Glutamatos/farmacologia , Guanina/análogos & derivados , Guanina/farmacologia , Humanos , Hidrolases/farmacologia , Hidrolases/toxicidade , Imuno-Histoquímica , Camundongos , Invasividade Neoplásica , Pemetrexede , Polietilenoglicóis/farmacologia , Polietilenoglicóis/toxicidade , Prognóstico , Pirimidinas/metabolismo , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/mortalidade , Microtomografia por Raio-X
4.
Mol Cancer ; 10: 68, 2011 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-21624135

RESUMO

BACKGROUND: Histone deacetylase (HDAC) inhibitors are currently undergoing clinical evaluation as anti-cancer agents. Dietary constituents share certain properties of HDAC inhibitor drugs, including the ability to induce global histone acetylation, turn-on epigenetically-silenced genes, and trigger cell cycle arrest, apoptosis, or differentiation in cancer cells. One such example is sulforaphane (SFN), an isothiocyanate derived from the glucosinolate precursor glucoraphanin, which is abundant in broccoli. Here, we examined the time-course and reversibility of SFN-induced HDAC changes in human colon cancer cells. RESULTS: Cells underwent progressive G2/M arrest over the period 6-72 h after SFN treatment, during which time HDAC activity increased in the vehicle-treated controls but not in SFN-treated cells. There was a time-dependent loss of class I and selected class II HDAC proteins, with HDAC3 depletion detected ahead of other HDACs. Mechanism studies revealed no apparent effect of calpain, proteasome, protease or caspase inhibitors, but HDAC3 was rescued by cycloheximide or actinomycin D treatment. Among the protein partners implicated in the HDAC3 turnover mechanism, silencing mediator for retinoid and thyroid hormone receptors (SMRT) was phosphorylated in the nucleus within 6 h of SFN treatment, as was HDAC3 itself. Co-immunoprecipitation assays revealed SFN-induced dissociation of HDAC3/SMRT complexes coinciding with increased binding of HDAC3 to 14-3-3 and peptidyl-prolyl cis/trans isomerase 1 (Pin1). Pin1 knockdown blocked the SFN-induced loss of HDAC3. Finally, SFN treatment for 6 or 24 h followed by SFN removal from the culture media led to complete recovery of HDAC activity and HDAC protein expression, during which time cells were released from G2/M arrest. CONCLUSION: The current investigation supports a model in which protein kinase CK2 phosphorylates SMRT and HDAC3 in the nucleus, resulting in dissociation of the corepressor complex and enhanced binding of HDAC3 to 14-3-3 or Pin1. In the cytoplasm, release of HDAC3 from 14-3-3 followed by nuclear import is postulated to compete with a Pin1 pathway that directs HDAC3 for degradation. The latter pathway predominates in colon cancer cells exposed continuously to SFN, whereas the former pathway is likely to be favored when SFN has been removed within 24 h, allowing recovery from cell cycle arrest.


Assuntos
Proteínas 14-3-3/metabolismo , Anticarcinógenos/farmacologia , Neoplasias do Colo/fisiopatologia , Histona Desacetilases/metabolismo , Correpressor 2 de Receptor Nuclear/metabolismo , Peptidilprolil Isomerase/metabolismo , Tiocianatos/farmacologia , Acetilação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias do Colo/enzimologia , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Ativação Enzimática/efeitos dos fármacos , Células HCT116 , Inibidores de Histona Desacetilases/farmacologia , Humanos , Isotiocianatos , Lisossomos/metabolismo , Modelos Biológicos , Peptidilprolil Isomerase de Interação com NIMA , Inibidores de Proteassoma , Ligação Proteica/fisiologia , Sulfóxidos
5.
Int J Cancer ; 126(12): 2762-72, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20104527

RESUMO

Arginine, a semi-essential amino acid in humans, is critical for the growth of human cancers, particularly those marked by de novo chemoresistance and a poor clinical outcome. In addition to protein synthesis, arginine is involved in diverse aspects of tumour metabolism, including the synthesis of nitric oxide, polyamines, nucleotides, proline and glutamate. Tumoural downregulation of the enzyme argininosuccinate synthetase (ASS1), a recognised rate-limiting step in arginine synthesis, results in an intrinsic dependence on extracellular arginine due to an inability to synthesise arginine for growth. This dependence on extracellular arginine is known as arginine auxotrophy. Several tumours are arginine auxotrophic, due to variable loss of ASS1, including hepatocellular carcinoma, malignant melanoma, malignant pleural mesothelioma, prostate and renal cancer. Importantly, targeting extracellular arginine for degradation in the absence of ASS1 triggers apoptosis in arginine auxotrophs. Several phase I/II clinical trials of the arginine-lowering drug, pegylated arginine deiminase, have shown encouraging evidence of clinical benefit and low toxicity in patients with ASS1-negative tumours. In part, ASS1 loss is due to epigenetic silencing of the ASS1 promoter in various human cancer cell lines and tumours, and it is this silencing that confers arginine auxotrophy. In relapsed ovarian cancer, this is associated with platinum refractoriness. In contrast, several platinum sensitive tumours, including primary ovarian, stomach and colorectal cancer, are characterised by ASS1 overexpression, which is regulated by proinflammatory cytokines. This review examines the prospects for novel approaches in the prevention, diagnosis and treatment of malignant disease based on ASS1 pathophysiology and its rate-limiting product, arginine.


Assuntos
Arginina/metabolismo , Argininossuccinato Sintase/metabolismo , Neoplasias/enzimologia , Neoplasias/terapia , Animais , Humanos , Neoplasias/patologia , Prognóstico
6.
Environ Mol Mutagen ; 50(3): 213-21, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19197985

RESUMO

Histone deacetylase (HDAC) inhibitors reactivate epigenetically-silenced genes in cancer cells, triggering cell cycle arrest and apoptosis. Recent evidence suggests that dietary constituents can act as HDAC inhibitors, such as the isothiocyanates found in cruciferous vegetables and the allyl compounds present in garlic. Broccoli sprouts are a rich source of sulforaphane (SFN), an isothiocyanate that is metabolized via the mercapturic acid pathway and inhibits HDAC activity in human colon, prostate, and breast cancer cells. In mouse preclinical models, SFN inhibited HDAC activity and induced histone hyperacetylation coincident with tumor suppression. Inhibition of HDAC activity also was observed in circulating peripheral blood mononuclear cells obtained from people who consumed a single serving of broccoli sprouts. Garlic organosulfur compounds can be metabolized to allyl mercaptan (AM), a competitive HDAC inhibitor that induced rapid and sustained histone hyperacetylation in human colon cancer cells. Inhibition of HDAC activity by AM was associated with increased histone acetylation and Sp3 transcription factor binding to the promoter region of the P21WAF1 gene, resulting in elevated p21 protein expression and cell cycle arrest. Collectively, the results from these studies, and others reviewed herein, provide new insights into the relationships between reversible histone modifications, diet, and cancer chemoprevention.


Assuntos
Compostos Alílicos/farmacologia , Anticarcinógenos/farmacologia , Alho/química , Inibidores de Histona Desacetilases , Isotiocianatos/farmacologia , Sulfetos/farmacologia , Tiocianatos/farmacologia , Compostos Alílicos/química , Compostos Alílicos/isolamento & purificação , Animais , Anticarcinógenos/química , Anticarcinógenos/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Isotiocianatos/química , Isotiocianatos/isolamento & purificação , Modelos Moleculares , Estrutura Molecular , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/prevenção & controle , Plantas Comestíveis/química , Ligação Proteica , Sulfetos/química , Sulfetos/isolamento & purificação , Sulfóxidos , Tiocianatos/química , Tiocianatos/isolamento & purificação
7.
Carcinogenesis ; 29(9): 1816-24, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18628250

RESUMO

Histone deacetylase (HDAC) inhibitors have the potential to derepress epigenetically silenced genes in cancer cells, leading to cell cycle arrest and apoptosis. In the present study, we screened several garlic-derived small organosulfur compounds for their ability to inhibit HDAC activity in vitro. Among the organosulfur compounds examined, allyl mercaptan (AM) was the most potent HDAC inhibitor. Molecular modeling, structure activity and enzyme kinetics studies with purified human HDAC8 provided evidence for a competitive mechanism (K(i) = 24 microM AM). In AM-treated human colon cancer cells, HDAC inhibition was accompanied by a rapid and sustained accumulation of acetylated histones in total cellular chromatin. Chromatin immunoprecipitation assays confirmed the presence of hyperacetylated histone H3 on the P21WAF1 gene promoter within 4 h of AM exposure, and there was increased binding of the transcription factor Sp3. At a later time, 24 h after AM treatment, there was enhanced binding of p53 in the distal enhancer region of the P21WAF1 gene promoter. These findings suggest a primary role for Sp3 in driving P21 gene expression after HDAC inhibition by AM, followed by the subsequent recruitment of p53. Induction of p21Waf1 protein expression was detected at time points between 3 and 72 h after AM treatment and coincided with growth arrest in G(1) of the cell cycle. The results are discussed in the context of other anticarcinogenic mechanisms ascribed to garlic organosulfur compounds and the metabolic conversion of such compounds to potential HDAC inhibitors in situ.


Assuntos
Compostos Alílicos/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Alho , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases , Regiões Promotoras Genéticas/genética , Fator de Transcrição Sp3/metabolismo , Acetilação , Ligação Competitiva , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Imunoprecipitação da Cromatina , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citometria de Fluxo , Células HT29 , Histona Desacetilase 1 , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Immunoblotting , Modelos Moleculares , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição Sp1/metabolismo , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
8.
Annu Rev Nutr ; 28: 347-66, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18598138

RESUMO

Post-translational modifications of histones are the subject of intensive investigations with the aim of decoding how they regulate, alone or in combination, chromatin structure, genomic stability, and gene expression. Major epigenetic programming events take place during gametogenesis and fetal development and are thought to have long-lasting consequences on adult health. Epidemiological and experimental studies have pointed toward maternal nutrition as a major player during prenatal development in influencing disease susceptibility later in life. Although the mechanisms underlying such observations are not well elucidated, epigenetic alterations of histones by particular maternal diets might be of central importance. Moreover, as much as dietary sources can influence epigenetic programming during pregnancy, they have started to be implicated in cancer chemoprevention, via the targeting of reversible epigenetic deregulations at the level of the histones.


Assuntos
Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Histonas/metabolismo , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Fenômenos Fisiológicos da Nutrição Pré-Natal/fisiologia , Animais , Metilação de DNA , Feminino , Transtornos da Nutrição Fetal/genética , Regulação da Expressão Gênica , Inativação Gênica , Humanos , Masculino , Fenômenos Fisiológicos da Nutrição Materna/genética , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Fenômenos Fisiológicos da Nutrição Pré-Natal/genética
9.
Nutr J ; 6: 20, 2007 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-17767717

RESUMO

BACKGROUND: Epidemiological studies on risk factors for colorectal cancer (CRC) have mainly focused on diet, and being overweight is now recognized to contribute significantly to CRC risk. Overweight and obesity are defined as an excess of adipose tissue mass and are associated with disorders in lipid metabolism. Peroxisome proliferator-activated receptors (PPARs) and retinoid-activated receptors (RARs and RXRs) are important modulators of lipid metabolism and cellular homeostasis. Alterations in expression and activity of these ligand-activated transcription factors might be involved in obesity-associated diseases, which include CRC. Cyclooxygenase-2 (COX-2) also plays a critical role in lipid metabolism and alterations in COX-2 expression have already been associated with unfavourable clinical outcomes in epithelial tumors. The objective of this study is to examine the hypothesis questioning the relationship between alterations in the expression of nuclear receptors and COX-2 and the weight status among male subjects with CRC. METHOD: The mRNA expression of the different nuclear receptor subtypes and of COX-2 was measured in 20 resected samples of CRC and paired non-tumor tissues. The association between expression patterns and weight status defined as a body mass index (BMI) was statistically analyzed. RESULTS: No changes were observed in PPAR gamma mRNA expression while the expression of PPAR delta, retinoid-activated receptors and COX-2 were significantly increased in cancer tissues compared to normal colon mucosa (P or= 25) compared to subjects with healthy BMI (P = 0.002). CONCLUSION: Our findings show that alterations in the pattern of nuclear receptor expression observed in CRC do not appear to be correlated with patient weight status. However, the analysis of COX-2 expression in normal colon mucosa from subjects with a high BMI suggests that COX-2 deregulation might be driven by excess weight during the colon carcinogenesis process.


Assuntos
Peso Corporal , Neoplasias Colorretais/genética , Ciclo-Oxigenase 2/genética , Expressão Gênica , Receptores Citoplasmáticos e Nucleares/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Neoplasias Colorretais/complicações , Humanos , Metabolismo dos Lipídeos/genética , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/genética , Sobrepeso/complicações , Sobrepeso/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Transcrição Reversa/fisiologia , Fatores de Risco
10.
Pharmacol Res ; 55(3): 224-36, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17317210

RESUMO

Cruciferous vegetables are a rich source of glucosinolates and their hydrolysis products, including indoles and isothiocyanates, and high intake of cruciferous vegetables has been associated with lower risk of lung and colorectal cancer in some epidemiological studies. Glucosinolate hydrolysis products alter the metabolism or activity of sex hormones in ways that could inhibit the development of hormone-sensitive cancers, but evidence of an inverse association between cruciferous vegetable intake and breast or prostate cancer in humans is limited and inconsistent. Organizations such as the National Cancer Institute recommend the consumption of five to nine servings of fruits and vegetables daily, but separate recommendations for cruciferous vegetables have not been established. Isothiocyanates and indoles derived from the hydrolysis of glucosinolates, such as sulforaphane and indole-3-carbinol (I3C), have been implicated in a variety of anticarcinogenic mechanisms, but deleterious effects also have been reported in some experimental protocols, including tumor promotion over prolonged periods of exposure. Epidemiological studies indicate that human exposure to isothiocyanates and indoles through cruciferous vegetable consumption may decrease cancer risk, but the protective effects may be influenced by individual genetic variation (polymorphisms) in the metabolism and elimination of isothiocyanates from the body. Cooking procedures also affect the bioavailability and intake of glucosinolates and their derivatives. Supplementation with I3C or the related dimer 3,3'-diindolylmethane (DIM) alters urinary estrogen metabolite profiles in women, but the effects of I3C and DIM on breast cancer risk are not known. Small preliminary trials in humans suggest that I3C supplementation may be beneficial in treating conditions related to human papilloma virus infection, such as cervical intraepithelial neoplasia and recurrent respiratory papillomatosis, but larger randomized controlled trials are needed.


Assuntos
Anticarcinógenos/farmacologia , Brassicaceae , Glucosinolatos/farmacologia , Neoplasias/prevenção & controle , Verduras , Animais , Brassicaceae/química , Estrogênios/metabolismo , Glutationa Transferase/genética , Humanos , Polimorfismo Genético , Fatores de Risco , Xenobióticos/metabolismo
11.
Int J Cancer ; 116(6): 839-46, 2005 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-15856452

RESUMO

Epidemiologic studies suggest that intake of high energy from fat, inducing overweight, increases the risk of cancer development and promotes colon carcinogenesis. It is therefore important to understand which parameters are affected early on by a high-fat diet in order to devise and improve protective nutritional strategies. We investigated the effect of high energy/fat intake on colon mucosa of male Wistar rats induced by a single 1,2-dimethylhydrazine (DMH) injection. Aberrant crypt foci (ACF) were numbered and modifications in cyclooxygenase-2 (COX-2) and beta-catenin levels assessed. Peroxisome proliferator- and retinoic acid-activated receptors (PPAR and RAR, RXR) are key transcription factors regulating gene expression in response to nutrient-activated signals. A short-term study was designed to evaluate whether alterations in mRNA expression of nuclear receptors can be detected at the beginning of the weight gain phase induced by an appetizing hyperlipidic diet (HLD). HLD consumption induced early downregulation of PPARgamma (-33.1%) and RARbeta (-53.1%) mRNA expression concomitant with an increase in levels of COX-2 (+45.5%) and beta-catenin (+84.56%) and in the number of ACF (191.56 +/- 88.60 vs. 21.14 +/- 11.64, p < 0.05). These findings suggest that HLD increases ACF occurrence, possibly through alterations in the mRNA expression profile of nuclear receptors. Moreover, the use HLD rich in retinyl esters or supplemented with all-trans retinoic acid led to a reduction in the number of ACF. Vitamin A also prevented HLD-induced alterations and the increase in levels of COX-2 and beta-catenin. The present observations show a protective role for vitamin A against disturbances associated with HLD exposure in induced colon carcinogenesis.


Assuntos
1,2-Dimetilidrazina/farmacologia , Proteínas do Citoesqueleto/genética , Gorduras na Dieta/metabolismo , Prostaglandina-Endoperóxido Sintases/genética , Receptores Citoplasmáticos e Nucleares/genética , Transativadores/genética , Vitamina A/farmacologia , Animais , Carcinógenos/farmacologia , Ciclo-Oxigenase 2 , Gorduras na Dieta/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores do Ácido Retinoico/efeitos dos fármacos , Receptores do Ácido Retinoico/genética , Tretinoína/farmacologia , beta Catenina
12.
Nutr Cancer ; 48(1): 28-36, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15203375

RESUMO

Some dietary compounds, among them fats, are modulators of colon cancer risk. This study reports the modulating effects of n-6, with or without vitamin A, on promotion of colon preneoplasic lesions induced by 1,2-dimethylhydrazine (DMH) and on the expression of nuclear receptors (PPARgamma, RXRalpha, and RARbeta). One group of male Fisher rats was fed a basic diet (5% safflower oil) and two groups were fed a high-fat diet (HFD, 25% safflower oil). Of these, one was supplemented with 200 IU vitamin A for 5 mo. The safflower oil contained polyunsaturated fatty acids, mainly linoleic acid (73%). The data showed an increasing effect of safflower oil-enriched diet on aberrant crypt foci occurrence and multiplicity. This effect was impaired by vitamin A supplementation. In addition, an HFD-related up-regulation of PPARgamma and a concomitant down-regulation of RARbeta mRNA expression were observed with or without chemical initiation and were prevented by vitamin A. Moreover, when treated with DMH, HFD rats exhibited a dramatically decreased expression of RXRalpha mRNA (-49%). It was hypothesized that HFD, leading to hyperexpression of PPARgamma, would produce an alteration of retinoic acid signaling and, in this way, create a background modulating colon cancer risk.


Assuntos
Neoplasias do Colo/metabolismo , Gorduras na Dieta/administração & dosagem , Proliferadores de Peroxissomos/metabolismo , RNA Mensageiro/metabolismo , Receptores do Ácido Retinoico/metabolismo , Vitamina A/metabolismo , 1,2-Dimetilidrazina , Animais , Colo/metabolismo , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Neoplasias do Colo/prevenção & controle , Gorduras na Dieta/efeitos adversos , Ácidos Graxos Ômega-6/administração & dosagem , Mucosa Intestinal/metabolismo , Masculino , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias Experimentais/prevenção & controle , Distribuição Aleatória , Ratos , Ratos Endogâmicos F344 , Receptores do Ácido Retinoico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Óleo de Cártamo/administração & dosagem , Óleo de Cártamo/química
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