RESUMO
Hyperhomocysteinemia (HHcy) is recognized as an independent risk factor for various significant medical conditions, yet controversy persists around its assessment and management. The diagnosis of disorders afffecting homocysteine (Hcy) metabolism faces delays due to insufficient awareness of its clinical presentation and unique biochemical characteristics. In cases of arterial or venous thrombotic vascular events, particularly with other comorbidities, it is crucial to consider moderate to severe HHcy. A nutritional approach to HHcy management involves implementing dietary strategies and targeted supplementation, emphasizing key nutrients like vitamin B6, B12, and folate that are crucial for Hcy conversion. Adequate intake of these vitamins, along with betaine supplementation, supports Hcy remethylation. Lifestyle modifications, such as smoking cessation and regular physical activity, complement the nutritional approach to enhance Hcy metabolism. For individuals with HHcy, maintaining a plasma Hcy concentration below 50 µmol/L consistently is vital to lowering the risk of vascular events. Collaboration with healthcare professionals and dietitians is essential for developing personalized dietary plans addressing the specific needs and underlying health conditions. This integrated approach aims to optimize metabolic processes and reduce the associated health risks.
Assuntos
Hiper-Homocisteinemia , Doenças Metabólicas , Adulto , Humanos , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/terapia , Artérias , Vitaminas , Terapia ComportamentalRESUMO
To better understand the causes of hypophosphatemia in children, we evaluated all serum phosphate tests performed in a tertiary hospital with unexpected but persistent temporary or isolated hypophosphatemia over an 18 year period. We collected 29,279 phosphate tests from 21,398 patients, of which 268 (1.2%) had at least one result showing hypophosphatemia. We found that endocrinopathies (n = 60), tumors (n = 10), and vitamin D deficiency (n = 3) were the medical conditions most commonly associated with mild hypophosphatemia, but in many patients the cause was unclear. Among patients with endocrinopathies, those with diabetes mellitus were found to have lower mean serum phosphate levels (mean 3.4 mg/dL) than those with short stature (3.7 mg/dL) or thyroid disorders (3.7 mg/dL). In addition, we found a correlation between glycemia and phosphatemia in patients with diabetes. However, despite the potential relevance of monitoring phosphate homeostasis and the underlying etiologic mechanisms, renal phosphate losses were estimated in less than 5% of patients with hypophosphatemia. In the pediatric age group, malignancies, hypovitaminosis D, and endocrine disorders, mostly diabetes, were the most common causes of hypophosphatemia. This real-world study also shows that hypophosphatemia is frequently neglected and inadequately evaluated by pediatricians, which emphasizes the need for more education and awareness about this condition to prevent its potentially deleterious consequences.
Assuntos
Diabetes Mellitus , Hipofosfatemia , Raquitismo , Humanos , Criança , Hipofosfatemia/etiologia , Fosfatos , Homeostase , Raquitismo/complicaçõesRESUMO
BACKGROUND: While therapeutic advances have significantly improved the prognosis of patients with hereditary tyrosinemia type 1 (HT1), adherence to dietary and pharmacological treatments is essential for an optimal clinical outcome. Poor treatment adherence is well documented among patients with chronic diseases, but data from HT1 patients are scarce. This study evaluated pharmacological and dietary adherence in HT1 patients both directly, by quantifying blood levels nitisinone (NTBC) levels and metabolic biomarkers of HT1 [tyrosine (Tyr), phenylalanine (Phe), and succinylacetone]; and indirectly, by analyzing NTBC prescriptions from hospital pharmacies and via clinical interviews including the Haynes-Sackett (or self-compliance) test and the adapted Battle test of patient knowledge of the disease. RESULTS: This observational study analyzed data collected over 4 years from 69 HT1 patients (7 adults and 62 children; age range, 7 months-35 years) who were treated with NTBC and a low-Tyr, low-Phe diet. Adherence to both pharmacological and, in particular, dietary treatment was poor. Annual data showed that NTBC levels were lower than recommended in more than one third of patients, and that initial Tyr levels were high (> 400 µM) in 54.2-64.4% of patients and exceeded 750 µM in 25.8% of them. Remarkably, annual normalization of NTBC levels was observed in 29.4-57.9% of patients for whom serial NTBC determinations were performed. Poor adherence to dietary treatment was more refractory to positive reinforcement: 36.2% of patients in the group who underwent multiple analyses per year maintained high Tyr levels during the entire study period, and, when considering each of the years individually this percentage ranged from 75 to 100% of them. Indirect methods revealed percentages of non-adherent patients of 7.3 and 15.9% (adapted Battle and Haynes tests, respectively). CONCLUSIONS: Despite initially poor adherence to pharmacological and especially dietary treatment among HT1 patients, positive reinforcement at medical consultations resulted in a marked improvement in NTBC levels, indicating the importance of systematic positive reinforcement at medical visits.
Assuntos
Tirosinemias , Adolescente , Adulto , Criança , Pré-Escolar , Cicloexanonas/uso terapêutico , Humanos , Lactente , Nitrobenzoatos/uso terapêutico , Fenilalanina , Prognóstico , Cooperação e Adesão ao Tratamento , Tirosina , Tirosinemias/tratamento farmacológico , Adulto JovemRESUMO
Incidental findings on newborn screening (NBS) are results that are not the target of screening within a given NBS program, but rather are found as a result of the screening and resulting diagnostic workup for that target. These findings may not have an immediate clinical impact on the newborn, but are sometimes an additional benefit of NBS programs and may be considered secondary targets of NBS programs. This work describes four case reports that had incidental findings on the NBS, which eventually led to the diagnosis of another metabolic disease instead of the one that was initially suspected. The first case was a new defect in the cationic amino acid transporter-2 (CAT-2), which was oriented as an arginase-1 deficiency in the newborn. The second case was a maternal glutaric aciduria type 1 (GA-1) that mimicked a carnitine transporter deficiency in the newborn. The third report was a case of lysinuric protein intolerance (LPI), which appeared as high levels of citrulline on the NBS. The fourth case was a mother with homocystinuria that was diagnosed during the biochemical study of vitamin B12 status. All cases provide new or interesting data that will help guide differential diagnosis in the future.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Encefalopatias Metabólicas/diagnóstico , Cardiomiopatias/diagnóstico , Carnitina/deficiência , Glutaril-CoA Desidrogenase/deficiência , Homocistinúria/diagnóstico , Hiperamonemia/diagnóstico , Doenças Musculares/diagnóstico , Triagem Neonatal/métodos , Erros Inatos do Metabolismo dos Aminoácidos/sangue , Encefalopatias Metabólicas/sangue , Cardiomiopatias/sangue , Carnitina/sangue , Teste em Amostras de Sangue Seco , Feminino , Glutaril-CoA Desidrogenase/sangue , Homocistinúria/sangue , Humanos , Hiperamonemia/sangue , Recém-Nascido , Masculino , Doenças Musculares/sangueRESUMO
Hypophosphataemic rickets is a heterogeneous group of entities characterized by rickets or osteomalacia due to a phosphate deficit caused mainly by decreased renal reabsorption. They are also characterized by defective intestinal absorption of calcium and rickets or osteomalacia unresponsive to cholecalciferol. These metabolic alterations lead to growth retardation, bone pain and deformities, and short stature. For a correct diagnosis and treatment of all forms of rickets, the basic aspects of pathophysiology of the calcium-phosphorus metabolism and the relevance of the bone-kidney axis modulated by the presence of phosphaturic agents need to be known. Diagnosis of these diseases includes clinical assessment, blood and urine analytical tests, and bone x-ray. The aim of this article is to briefly describe the pathophysiology, signs, symptoms, and clinical forms of hypophosphataemic rickets, proposing a diagnosis algorithm that can help in the clinical practice.
Assuntos
Algoritmos , Cálcio/metabolismo , Diagnóstico Diferencial , Fosfatos/metabolismo , Raquitismo Hipofosfatêmico/diagnóstico , Raquitismo Hipofosfatêmico/fisiopatologia , Avaliação de Sintomas/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cálcio/sangue , Criança , Pré-Escolar , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fosfatos/sangueRESUMO
The aim of this study was to examine whether a type of exercise favors better compliance with a prescribed diet, higher eating-related motivation, healthier diet composition or greater changes in body composition in overweight and obese subjects. One hundred and sixty-two (males n = 79), aged 18-50 years, were randomized into four intervention groups during 24 weeks: strength, endurance, combined strength + endurance and guideline-based physical activity; all in combination with a 25-30% caloric restriction diet. A food frequency questionnaire and a "3-day food and drink record" were applied pre- and post-intervention. Diet and exercise-related motivation levels were evaluated with a questionnaire developed for this study. Body composition was assessed by DXA and habitual physical activity was measured by accelerometry. Body weight, body mass index (BMI) and body fat percentage decreased and lean body mass increased after the intervention, without differences by groups. No interactions were observed between intervention groups and time; all showing a decreased in energy intake (p < 0.001). Carbohydrate and protein intakes increased, and fat intake decreased from pre- to post-intervention without significant interactions with intervention groups, BMI category or gender (p < 0.001). Diet-related motivation showed a tendency to increase from pre- to post-intervention (70.0 ± 0.5 vs 71.0 ± 0.6, p = 0.053), without significant interactions with intervention groups, BMI or gender. Regarding motivation for exercise, gender x time interactions were observed (F(1,146) = 7.452, p = 0.007): Women increased their motivation after the intervention (pre: 17.6 ± 0.3, post: 18.2 ± 0.3), while men maintained it. These findings suggest that there are no substantial effects of exercise type on energy intake, macronutrient selection or body composition changes. After a six-month weight loss program, individuals did not reduce their motivation related to diet or exercise, especially women. Individuals who initiate a long-term exercise program do not increase their energy intake in a compensatory fashion, if diet advices are included.
Assuntos
Composição Corporal , Comportamento Alimentar/psicologia , Obesidade/terapia , Sobrepeso/terapia , Programas de Redução de Peso/métodos , Acelerometria , Adolescente , Adulto , Índice de Massa Corporal , Dieta Redutora/psicologia , Ingestão de Energia , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Obesidade/fisiopatologia , Obesidade/psicologia , Sobrepeso/fisiopatologia , Sobrepeso/psicologia , Fatores Sexuais , Adulto JovemRESUMO
ADNP syndrome is an intellectual disability associated with Autism spectrum disorder caused by mutations in ADNP. We generated an iPSC line from an ADNP syndrome pediatric patient harboring the mutation p.Trp719* (GENYOi004-A). Peripheral blood mononuclear cells were reprogrammed using a non-transmissible form of Sendai viruses expressing the four Yamanaka factors (Oct3/4, SOX2, KLF4 and c-MYC). Characterization of GENYOi004-A included mutation analysis of ADNP by allele-specific PCR, genetic identity by Short Tandem Repeats polymorphism profiling, alkaline phosphatase enzymatic activity, expression of pluripotency-associated factors and pluripotency studies in vivo. GENYOi004-A will be useful to evaluate ADNP syndrome alterations at early developmental stages.
Assuntos
Transtorno do Espectro Autista/genética , Diferenciação Celular , Proteínas de Homeodomínio/genética , Células-Tronco Pluripotentes Induzidas/patologia , Leucócitos Mononucleares/patologia , Mutação , Proteínas do Tecido Nervoso/genética , Teratoma/etiologia , Animais , Transtorno do Espectro Autista/patologia , Células Cultivadas , Reprogramação Celular , Criança , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator 4 Semelhante a Kruppel , Leucócitos Mononucleares/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fenótipo , Teratoma/patologiaRESUMO
AIM: To explore the clinical presentation, course, treatment and impact of early treatment in patients with remethylation disorders from the European Network and Registry for Homocystinurias and Methylation Defects (E-HOD) international web-based registry. RESULTS: This review comprises 238 patients (cobalamin C defect n = 161; methylenetetrahydrofolate reductase deficiency n = 50; cobalamin G defect n = 11; cobalamin E defect n = 10; cobalamin D defect n = 5; and cobalamin J defect n = 1) from 47 centres for whom the E-HOD registry includes, as a minimum, data on medical history and enrolment visit. The duration of observation was 127 patient years. In 181 clinically diagnosed patients, the median age at presentation was 30 days (range 1 day to 42 years) and the median age at diagnosis was 3.7 months (range 3 days to 56 years). Seventy-five percent of pre-clinically diagnosed patients with cobalamin C disease became symptomatic within the first 15 days of life. Total homocysteine (tHcy), amino acids and urinary methylmalonic acid (MMA) were the most frequently assessed disease markers; confirmatory diagnostics were mainly molecular genetic studies. Remethylation disorders are multisystem diseases dominated by neurological and eye disease and failure to thrive. In this cohort, mortality, thromboembolic, psychiatric and renal disease were rarer than reported elsewhere. Early treatment correlates with lower overall morbidity but is less effective in preventing eye disease and cognitive impairment. The wide variation in treatment hampers the evaluation of particular therapeutic modalities. CONCLUSION: Treatment improves the clinical course of remethylation disorders and reduces morbidity, especially if started early, but neurocognitive and eye symptoms are less responsive. Current treatment is highly variable. This study has the inevitable limitations of a retrospective, registry-based design.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/terapia , Homocistinúria/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/metabolismo , Vitamina B 12/metabolismo , Adolescente , Adulto , Idade de Início , Criança , Pré-Escolar , Estudos Transversais , Progressão da Doença , Europa (Continente) , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Ácido Metilmalônico/urina , Fenótipo , Gravidez , Transtornos Psicóticos/metabolismo , Sistema de Registros , Estudos Retrospectivos , Adulto JovemRESUMO
To evaluate the prognostic significance of factors frequently associated with a reduction in renal mass, such as prematurity, low birth weight, and congenital anomalies of kidney and urinary tract (CAKUT), in patients with solitary functioning kidney (SFK) and investigate signs of early renal injury due to glomerular hyperfiltration damage or dysplasia in the remaining kidney.Retrospective observational study of congenital SFK diagnosed and followed at a tertiary care hospital over a period of 10 years in which 32,900 newborns underwent routine neonatal abdominal ultrasound screening. We analyzed age at diagnosis, sex, gestational age, anthropometric measurements at birth and prenatal and neonatal ultrasound findings, in addition to follow-up data corresponding to imaging findings (ultrasound, micturating cystourethrography, dimercaptosuccinic acid renal, and scintigraphy), ipsilateral CAKUT, compensatory hypertrophy, and renal injury in the form of albuminuria, blood pressure, and estimated glomerular filtration rate (eGFR).In total, 128 congenital SFK cases were detected (1 per 257 live births). Of these, 117 (91.4%) were diagnosed by neonatal ultrasound screening and 44.5% of these had been previously identified by prenatal ultrasound. Neonatal ultrasound had a specificity of 100% and a sensitivity of 92.1%. Forty-five patients (35.2%) had ipsilateral CAKUT and the most common type was urinary collecting system anomalies (75.5%). Over a median follow-up of 6.3 years (1-10 years), compensatory renal hypertrophy was observed in 81 patients (63.7%), most of whom had ipsilateral CAKUT (76.1% vs 56.6% of patients without ipsilateral CAKUT). Albuminuria and hypertension were observed in 3.12% and 5% of patients, respectively, and both were associated with ipsilateral CAKUT (Pâ<â.05). In addition, 75% of albuminuria cases (Pâ=â.031), 83.3% of hypertension cases (Pâ=â.004), and 100% of decreased eGFRcases (Pâ=â.031) were significantly associated with CAKUT (renal parenchymal anomaly category), being the strongest predictor of GFR the presence or absence of CAKUT.Neonatal ultrasound screening is useful for the early diagnosis of SFK. The presence of ipsilateral CAKUT should be evaluated in all patients with SFK as congenital anomalies of the renal parenchyma are associated with a poorer prognosis. Because morbidity from CAKUTs may not develop until adulthood, patients should be closely followed throughout life.
Assuntos
Insuficiência Renal Crônica/epidemiologia , Rim Único/diagnóstico , Rim Único/epidemiologia , Albuminúria/epidemiologia , Pesos e Medidas Corporais , Feminino , Idade Gestacional , Taxa de Filtração Glomerular , Humanos , Hipertensão/epidemiologia , Recém-Nascido , Masculino , Triagem Neonatal/métodos , Estudos Retrospectivos , Fatores de Risco , Sensibilidade e Especificidade , Fatores Sexuais , Rim Único/diagnóstico por imagemRESUMO
BACKGROUND: apolipoprotein E (ApoE) polymorphism is a genetic determinant of lipid and lipoprotein levels and the risk for coronary heart disease. OBJECTIVE: to evaluate the impact of ApoE2allele in lipid plasma levels and the influence of a healthy hypocaloric diet plus a controlled physical activity on the lipid profile, we performed a study in a cohort of overweight and obese healthy subjects (Body Mass Index (BMI) between 25 and 34.9 kg·m-2). METHODS: one hundred eighty participants (96 women), aged 18-50 years participated in a 22 weeks weight loss intervention based on same dietary treatment and different controlled exercise programs. All subjects followed a hypocaloric diet (25-30% less energy intake than the daily energy expenditure). Blood samples were obtained for lipids measurements at the beginning and end of the study. RESULTS: after intervention, men of the E2 group showed the greatest decreases in low-density lipoprotein (LDL), triglycerides (TG) and total cholesterol (TC) values (p = 0.039; p = 0.001; p = 0.001; respectively). For high-density lipoprotein (HDL), E2 group had significant differences compared with E4 at pre- (p = 0.020) and post-intervention values (p = 0.024). CONCLUSION: our results show great changes in men carrying ApoE2, mainly in TG and TC concentrations after treatment with hypocaloric diet and controlled exercise. Therefore, adding supervised training to nutritional intervention seems to be a good alternative for the reinforcement of the effect of the treatment.
Assuntos
Apolipoproteínas E/genética , Lipídeos/sangue , Redução de Peso/genética , Adulto , Apolipoproteína E2/genética , Estudos de Coortes , Dieta Redutora , Exercício Físico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/genética , Obesidade/terapia , Sobrepeso/genética , Sobrepeso/terapia , Programas de Redução de PesoRESUMO
Cutaneous vasculitis may be associated with malignancies, and may behave as a paraneoplastic syndrome. This association has been reported in a variable proportion of patients depending on population selection. We conducted the current study to assess the frequency, clinical features, treatment, and outcome of paraneoplastic vasculitis in a large unselected series of 766 patients with cutaneous vasculitis diagnosed at a single university hospital. Sixteen patients (10 men and 6 women; mean age ± standard deviation, 67.94 ± 14.20 yr; range, 40-85 yr) presenting with cutaneous vasculitis were ultimately diagnosed as having an underlying malignancy. They constituted 3.80% of the 421 adult patients. There were 9 hematologic and 7 solid underlying malignancies. Skin lesions were the initial clinical presentation in all of them, and the median interval from the onset of cutaneous vasculitis to the diagnosis of the malignancy was 17 days (range, 8-50 d). The most frequent skin lesions were palpable purpura (15 patients). Other clinical manifestations included constitutional syndrome (10 patients) and arthralgia and/or arthritis (4 cases). Hematologic cytopenias (11 cases) as well as immature peripheral blood cells (6 cases) were frequently observed in the full blood cell count, especially in those with vasculitis associated with hematologic malignancies. Specific treatment for vasculitis was prescribed in 10 patients; nonsteroidal antiinflammatory drugs (4 patients), corticosteroids (3 patients), chloroquine (1 patient), antihistamines (1 patient), and cyclophosphamide (1 patient). Ten patients died due to the malignancy and 6 patients recovered following malignancy therapy. Patients with paraneoplastic vasculitis were older, more frequently had constitutional syndrome, and less frequently had organ damage due to the vasculitis than the remaining patients with cutaneous vasculitis. In summary, cutaneous paraneoplastic vasculitis is an entity not uncommonly encountered by clinicians. The most common underlying malignancy is generally hematologic. In these cases the presence of cytopenias and immature cells may be red flags for the diagnosis of cancer. In patients with paraneoplastic cutaneous vasculitis, the prognosis depends on the underlying neoplasia.
Assuntos
Síndromes Paraneoplásicas/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/tratamento farmacológico , Vasculite Leucocitoclástica Cutânea/diagnóstico , Vasculite Leucocitoclástica Cutânea/tratamento farmacológico , Vasculite Leucocitoclástica Cutânea/epidemiologia , Adulto JovemRESUMO
This report describes a three-generation family with a severe phenotype of long-QT syndrome-1 (LQTS-1) caused by a single nucleotide mutation in the KQT-like, voltage-gated potassium channel-1 gene (KCNQ1; MIM 607542). Two members of the family died suddenly in their childhood, and all eight surviving members with prolonged QT have a heterozygous missense mutation resulting in a glycine-to-glutamate amino acid substitution at position 316 of the potassium channel. In this family, the newly reported mutation, guanine-to-adenosine at position 947 in the KCNQ1 gene, exhibits a dominant trait of LQTS with complete penetrance, in contrast to the relatively reduced clinical penetrance found in most LQTS cases.
Assuntos
Predisposição Genética para Doença , Síndrome de Romano-Ward/genética , Feminino , Humanos , Canal de Potássio KCNQ1 , Masculino , Mutação de Sentido Incorreto , LinhagemRESUMO
The possibility of modifying apoptosis-related genes in tumor cells is an interesting line of research that calls for multidisciplinary experimentation to describe its characteristics and the conditions required. In vitro low doses of alpha particle irradiation due to radon have an antiproliferative effect on the growth of MCF-7 cells and increase the sensibility of cancer cells to taxol, a chemotherapeutic agent that induces cellular apoptosis. The present study examines the in vitro effects of low doses of alpha particle irradiation from the gas radon on the expression of some bcl-2 family apoptosis-related genes. The analyzed genes were bax, bcl-2 and bcl-x, with known responses to genotoxic stress (bcl-2) or ionising radiation (bax and bcl-x) in MCF-7 human breast cancer cells. The results obtained indicate that the cell line studied expresses the mentioned genes and they demonstrate that irradiation with low radon doses of MCF-7 cells induces underexpression of both bax and bcl-2 genes. Interestingly, the mRNA levels of the full-length bcl-x gene (bcl-xL) were overexpressed after irradiation, and we found significant mRNA levels of an alternative mRNA splicing form of the same gene (bcl-xS), which enhances the apoptotic sensitivity of the cell. The increased sensitivity to apoptosis resulting from bcl-xS overexpression is important because it might improve the efficacy of chemotherapeutic agents used to treat cancers which act through induction of apoptosis. The finding that low radiation doses of alpha particles from the gas radon modulate the expression of apoptosis-related genes suggests a therapeutic utility for this naturally occurring agent.
Assuntos
Partículas alfa , Proteínas Reguladoras de Apoptose/genética , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Sequência de Bases , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Humanos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Proteína X Associada a bcl-2/genética , Proteína bcl-X/genéticaRESUMO
Melatonin inhibits proliferation of the estrogen-responsive MCF-7 human breast cancer cells. The objective of this work was to assess whether melatonin not only regulates MCF-7 cell proliferation but also induces apoptosis. In this experiment we used 1,25-dihydroxycholecalciferol (D3) as a positive control because it inhibits MCF-7 cell proliferation and induces apoptosis. MCF-7 cells were cultured with either I nM melatonin, 100 nM D3 or its diluent to determine their effects on cell proliferation, cell viability, cell-cycle phase distribution, population of apoptotic cells, and expression of p53, p21WAF1, bcl-2, bcl-X(L) and bax proteins. After 24 or 48 hr of incubation, both melatonin and D3-treatment significantly decreased the number of viable cells in relation to the controls, although no differences in cell viability were observed between the treatments. The incidence of apoptosis, measured as the population of cells falling in the sub-G1 region of the DNA histogram, or by the TUNEL reaction, was similar in melatonin-treated and control cells whereas, as expected, apoptosis was higher among cells treated with D3 than in controls. The expression of p53 and p21WAF1 proteins significantly increased after 24 or 48 hr of incubation with either melatonin or D3. No significant changes in bcl-2, bcl-XL and bax mRNAs were detected after treatment with melatonin whereas in D3-treated cells, a significant drop in bcl-XL was observed. These data support the hypothesis that melatonin reduces MCF-7 cell proliferation by modulating cell-cycle length through the control of the p53-p21 pathway, but without clearly inducing apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Melatonina/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Colecalciferol/farmacologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/efeitos dos fármacos , Ciclinas/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Proto-Oncogênicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2 , Proteína bcl-XRESUMO
In vitro, cells derived from Ewing sarcoma (ES) with the characteristic somatic rearrangement between the genes EWS and FLII can be induced to differentiate toward a neuronal phenotype by exposure to agents such as dibutyryl cyclic AMP (db cAMP) or retinoic acid. Therefore, expression of the chimeric Ews-Flil protein does not irreversibly block the capacity of Ewing cells to engage in the neuronal differentiation program initiated by these agents. To identify genes that might be involved in the maintenance of Ewing cells in their undifferentiated state, a PCR-based differential display method was used to compare gene expression patterns in Ewing cell lines with those induced to differentiate toward a neuronal phenotype. A cDNA was expressed at high levels in proliferating Ewing-derived EW-1 cells and downregulated in EW-1 cells induced to differentiate, which corresponds to ZNF43, a multi-zinc finger protein containing the Krüppel-associated box (KRAB) transcriptional repression domain. Treatment of EW-1 cells with antisense oligonucleotides complementary to ZNF43 mRNA induces morphological differentiation and growth arrest. These findings suggest a role for ZNF43 in the maintenance of ES cells in an undifferentiated state, and that ZNF43 could be a primary target for differentiation stimuli in Ewing cells.