RESUMEN

Many cancer patients receive their classical therapies together with vitamin supplements. However, the effectiveness of these strategies is on debate. Here we aimed to evaluate how vitamin E supplementation affects the anticancer effects of interferon (IFN-α) using an early-model of liver cancer development (initiation-promotion, IP). Male Wistar rats subjected to this model were divided as follows: untreated (IP), IP treated with recombinant IFN-α-2b (6.5  ×  105 U/kg), IP treated with vitamin E (50 mg/kg), and IP treated with combination of vitamin E and IFN-α-2b. After treatments rats were fasted and euthanized and plasma and livers were collected. Combined administration of vitamin E and IFN-α-2b induced body weight drop, increased liver apoptosis, and low levels of hepatic lipids. Interestingly, vitamin E and IFN-α-2b combination also induced an increase in altered hepatic foci number, but not in size. It seems that vitamin E acts on its antioxidant capability in order to block the oxidative stress induced by IFN-α-2b, blocking in turn its beneficial effects on preneoplastic livers, leading to harmful final effects. In conclusion, this study shows that vitamin E supplementation in IFN-α-2b-treated rats exerts unwanted effects; and highlights that in spite of being natural, nutritional supplements may not always exert beneficial outcomes when used as complementary therapy for the treatment of cancer.

Asunto(s)

Anticarcinógenos/farmacología , Interferón alfa-2/farmacología , Neoplasias Hepáticas/prevención & control , Vitamina E/farmacología , Vitaminas/farmacología , Animales , Carcinogénesis/efectos de los fármacos , Carcinogénesis/patología , Interacciones Farmacológicas , Hígado/efectos de los fármacos , Hígado/patología , Neoplasias Hepáticas/patología , Masculino , Ratas Wistar

RESUMEN

IFN-α administration to patients has been long discouraged and pushed back by new and apparently better drugs; however the adverse secondary effect, the high costs and the lack of specific action, make these new drugs hard to be used and put IFN-α again in the eye of the researchers. IFN-α-2b was demonstrated to induce apoptosis and modulation of lipid metabolism and the mechanisms are still unknown. Here, we sought to find the link between these features using a model of early stage cancer development. Using in vitro and in vivo approaches, we evaluated apoptosis and lipid metabolism. IFN-α-2b induced changes in hepatic cholesterol mass due to decreased synthesis and increased secretion. Interestingly, the drop in cellular cholesterol levels was necessary for IFN-α-2b to induce apoptosis. Results presented in this paper show the complexity of the action of IFN-α-2b on the early stages of liver cancer development. We show for the first time an interrelationship between cholesterol, apoptosis and IFN-α-2b. This makes clear the need for a reevaluation of IFN-α-2b action in order to develop softer, safer and more bearable derivatives. In this regard, knowing the molecular mechanisms by which IFN-α exerts its cellular actions is of crucial importance, and it is the main condition for therapy success for classical and new malignancies.

Asunto(s)

Apoptosis/efectos de los fármacos , Colesterol/metabolismo , Hepatocitos/efectos de los fármacos , Interferón alfa-2/farmacología , Animales , Línea Celular Tumoral , Hepatocitos/metabolismo , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Neoplasias Hepáticas/metabolismo , Masculino , Ratas , Ratas Wistar

RESUMEN

IFN-α is used for inflammatory purposes, and obesity and NAFLD are strongly correlated with inflammatory processes. We wondered whether IFN-α-2b can attenuate obesity development and its associated NAFLD in mice fed high fat diet (HFD) for 10 weeks. IFN-α-2b had a robust effect on body weight loss associated with NAFLD amelioration by decreasing hepatic inflammation. IFN-α-2b-treated mice showed increased plasma cholesterol levels together with decreased hepatic cholesterol, both on chow and HF diets. Interestingly, mice on IFN-α-2b treatment secreted smaller VLDL particles highly enriched in cholesterol. Mechanistically, we found that IFN-α-2b antiobesity effects were related to increased fatty acid oxidation; and its effects on cholesterol metabolism were due to both a decrease in the master cholesterogenic transcription factor SREBP-2 and in the rate limiting enzyme in cholesterol synthesis, HMGCR. To our knowledge, this is the first report showing the effects of IFN-α-2b on the prevention of the development of HFD-induced body weight gain and dyslipidemia through a mechanism that involves fatty acid oxidation and cholesterol decrease. These studies comprise necessary steps for understanding the amelioration of obesity and NAFLD. Results shed some light into the mechanism of action of natural cytokines, and their effects on ameliorating obesity and its related diseases.

Asunto(s)

Interferón alfa-2/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Obesidad/prevención & control , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Dislipidemias/tratamiento farmacológico , Ácidos Grasos/metabolismo , Lípidos/sangre , Lipoproteínas/sangre , Lipoproteínas VLDL/sangre , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/patología , Hipernutrición/complicaciones , Reacción en Cadena en Tiempo Real de la Polimerasa

RESUMEN

OBJECTIVE: Vitamin K2, which is present in dairy products and has been recommended as a micronutrient supplement in humans, contains anticancer properties. Interferon (IFN)-α-2b administered during development of hepatic preneoplasia decreased both number and volume percentage of altered hepatic foci (AHF) by increasing apoptosis in the foci. The aim of this study was to evaluate the effects of IFN-α-2b treatment supplemented with vitamin K2 in the early stages of liver cancer development in rats. METHODS: Adult male Wistar rats were subjected to a two-phase model of hepatocarcinogenesis (initiated-promoted [IP] group). Animals were divided into four groups: untreated (IP), IP treated with IFN-α-2b (6.5 × 105 U/kg), IP treated with vitamin K2 (10 mg/kg), and IP treated with both compounds. RESULTS: The study results demonstrated that vitamin K2 blocked IFN-α-2b-induced reduction in size and volume of the altered hepatic foci and inhibited IFN-α-2b-induced apoptosis. Its inhibition of IFN-α-2b-induced apoptosis was mediated by increased levels of total hepatic Bcl-2 in rat preneoplastic livers. CONCLUSION: These findings demonstrate that supportive vitamin supplements or therapies are not always safe because they could put the life of patients treated with IFN-α-2b at risk.

Asunto(s)

Antineoplásicos/administración & dosificación , Carcinogénesis/efectos de los fármacos , Suplementos Dietéticos , Interferón alfa-2/administración & dosificación , Vitamina K 2/administración & dosificación , Vitaminas/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Hígado/efectos de los fármacos , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Lesiones Precancerosas/tratamiento farmacológico , Ratas , Ratas Wistar

RESUMEN

PURPOSE: Glycerol usage is increasing in food industry for human and animal nutrition. This study analyzed the impact of glycerol metabolism when orally supplemented during the early stage of rat liver carcinogenesis. METHODS: Wistar rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP group). IP animals also received glycerol by gavage (200 mg/kg body weight, IPGly group). RESULTS: Glycerol treatment reduced the volume of preneoplastic lesions by decreasing the proliferative status of liver foci, increasing the expression of p53 and p21 proteins and reducing the expression of cyclin D1 and cyclin-dependent kinase 1. Besides, apoptosis was enhanced in IPGly animals, given by an increment of Bax/Bcl-2 ratio, Bad and PUMA mitochondrial expression, a concomitant increase in cytochrome c release and caspase-3 activation. Furthermore, hepatic levels of glycerol phosphate and markers of oxidative stress were increased in IPGly rats. Oxidative stress intermediates act as intracellular messengers, inducing p53 activation and changes in JNK and Erk signaling pathways, with JNK activation and Erk inhibition. CONCLUSION: The present work provides novel data concerning the preventive actions of glycerol during the development of liver cancer and represents an economically feasible intervention to treat high-risk individuals.

Asunto(s)

Anticarcinógenos/uso terapéutico , Apoptosis , Suplementos Dietéticos , Glicerol/uso terapéutico , Neoplasias Hepáticas Experimentales/prevención & control , Estrés Oxidativo , Lesiones Precancerosas/prevención & control , Animales , Anticarcinógenos/sangre , Anticarcinógenos/metabolismo , Biomarcadores/sangre , Carcinogénesis , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Glicerol/sangre , Glicerol/metabolismo , Peroxidación de Lípido , Hígado/enzimología , Hígado/metabolismo , Hígado/patología , Neoplasias Hepáticas Experimentales/sangre , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/patología , Sistema de Señalización de MAP Quinasas , Masculino , Mitocondrias Hepáticas/enzimología , Mitocondrias Hepáticas/metabolismo , Mitocondrias Hepáticas/patología , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fosforilación , Lesiones Precancerosas/sangre , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Ratas Wistar , Carga Tumoral

RESUMEN

It is accepted that cancer development is associated with metabolic changes. Previously, we established a model of hepatic preneoplasia in which adult rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP) for 6weeks until they develop altered hepatic foci (AHF). Here, we found that a whole metabolic shift occurs in order to favor cancer development. IP animals presented with increased plasma lipids due to increased VLDL secretion as well as increased liver lipid accretion due to stimulated transacetylase activity rather than lipogenesis, compared to control rats. We found that carboxylesterase 3/triacylglycerol hydrolase (Ces3/Tgh) presented with a perilobular distribution surrounding lipid droplets in normal livers. However, it is downregulated both at the protein and mRNA level in liver homogenates and is almost undetectable inside the AHF with no changes in the surrounding tissue. Ces3/Tgh expression is regulated by ω-3 fatty acids, thus, supplementation of diet with fish oil, allowed the restoration of Ces3/Tgh expression inside the foci and, more interestingly, led to the decrease in number and volume of the AHF. These studies show a preventive role of Ces3/Tgh in liver cancer development.

RESUMEN

BACKGROUND: FoxO3a, a member of the FOXO family of transcription factors, is expressed in adult liver and modulates the expression of genes involved in apoptosis. FoxO3a is post-translationally regulated, negatively by PI3K/Akt and MAPK/Erk and positively by oxidative stress/JNK pathways. In previous works, we have demonstrated that interferon-α2b (IFN-α2b) induces apoptosis of hepatic preneoplastic foci through the production of reactive oxygen species (ROS). AIMS: To investigate the post-translational signal events triggered by the oxidative stress induced by IFN-α2b and the modulation of FoxO3a transcriptional activity during these events in rat preneoplastic liver. METHODS: Adult male Wistar rats were subjected to a two-phase model of hepatocarcinogenesis. A group of animals received IFN-α2b and another group received IFN-α2b and ascorbic acid (ASC), by intraperitoneal injection. Lipid peroxidation, immunohistochemistry, immunoblotting, co-immunoprecipitation and sqRT-PCR assays were performed to explore the role of ROS, JNK, Akt, Erk, FoxO3a, ß-catenin and PUMA in the IFN-α2b-mediated apoptotic mechanism. RESULTS: In vivo IFN-α2b treatment induced endogenous production of ROS which activated JNK. IFN-α2b blocked the activation of Akt and Erk, avoiding FoxO3a activity repression. Activated JNK was responsible for the nuclear translocation and transcriptional activity of FoxO3a which positively modulated the expression of PUMA, a proapoptotic player. In addition, nuclear FoxO3a competed for the nuclear ß-catenin associated to TCF, inhibiting the canonical Wnt signalling pathway. CONCLUSIONS: The data presented here propose a model in which in vivo IFN-α2b treatment induces nuclear translocation and transcriptional activity of FoxO3a, triggering the mitochondrial apoptotic pathway in hepatic preneoplastic foci.

Asunto(s)

Apoptosis/genética , Carcinogénesis/efectos de los fármacos , Factores de Transcripción Forkhead/metabolismo , Regulación de la Expresión Génica/fisiología , Hígado/metabolismo , Estrés Oxidativo/fisiología , Transducción de Señal/fisiología , Animales , Proteína Forkhead Box O3 , Regulación de la Expresión Génica/genética , Immunoblotting , Inmunohistoquímica , Inmunoprecipitación , Interferón alfa-2 , Interferón-alfa/farmacología , Peroxidación de Lípido , Masculino , Modelos Biológicos , Procesamiento Proteico-Postraduccional/genética , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética

RESUMEN

OBJECTIVE: A one-tube nested RT-PCR protocol was set up and used to detect mammaglobin A (MGA) expression in blood samples from breast cancer patients. The correlation of MGA detection with prognostic factors was analyzed. DESIGN AND METHODS: Total RNA from nucleated blood cells was extracted from 65 breast cancer patients (before surgery and after the treatments) and 18 healthy subjects and used to detect MGA expression by a modified nested RT-PCR. RESULTS: MGA expression was detected in 38.4% of patients before surgery, and in 50% and 36.8% of post-treatment samples from patients that expressed MGA or were MGA negative before surgery, respectively. MGA detection was associated with the absence of tumor estrogen receptors (p=0.004). CONCLUSIONS: MGA detection by the modified nested RT-PCR is a specific marker for circulating tumor cells in patients with breast carcinoma and a negative prognostic factor for the disease.

Asunto(s)

Biomarcadores de Tumor/sangre , Neoplasias de la Mama/sangre , Carcinoma Ductal de Mama/sangre , Carcinoma Lobular/sangre , Mamoglobina A/sangre , Receptores de Estrógenos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patología , Carcinoma Ductal de Mama/terapia , Carcinoma Lobular/metabolismo , Carcinoma Lobular/patología , Carcinoma Lobular/terapia , Estudios de Casos y Controles , Femenino , Expresión Génica , Humanos , Metástasis Linfática , Mamoglobina A/genética , Persona de Mediana Edad , Células Neoplásicas Circulantes , Reacción en Cadena de la Polimerasa , Adulto Joven

RESUMEN

We analyzed the contribution of TNF-α intracellular pathway in the development of apoptosis in the liver of streptozotocin-induced diabetic rats. In liver tissue, diabetes promoted a significant increase of TNF-α/TNF-R1, and led to the activation of caspase-8, of nuclear factor kappa B (NFκB), and JNK signaling pathways. The activation of NFκB led to an induction of iNOS and consequent increase in NO production. As a consequence of such changes a significant increase of caspase-3 activity and of apoptotic index were observed in the liver of diabetic animals. Importantly, the treatment in vivo of diabetic rats with etanercept (TNF-α blocking antibody) or aminoguanidine (selective iNOS inhibitor) significantly attenuated the induction of apoptosis by reduction of caspase-3 activity. Overall, we demonstrated that in the diabetes enhances TNF-α in the liver, which may be a fundamental key leading to apoptotic cell death, through activation of caspase-8, NFκB and JNK pathways.

Asunto(s)

Apoptosis , Diabetes Mellitus Tipo 1/metabolismo , Hígado/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Western Blotting , Caspasa 3/metabolismo , Caspasa 8/metabolismo , Inhibidores de Caspasas , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1/patología , Espectroscopía de Resonancia por Spin del Electrón , Etanercept , Guanidinas/farmacología , Inmunoglobulina G/farmacología , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Hígado/patología , Masculino , FN-kappa B/metabolismo , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo II/metabolismo , Ratas , Ratas Wistar , Receptores del Factor de Necrosis Tumoral , Transducción de Señal , Estreptozocina

RESUMEN

Wnt/beta-catenin/T cell factor (TCF) pathway is activated in several types of human cancers, promoting cell growth and proliferation. Forkhead box containing protein class O (FOXO) transcription factors compete with TCF for beta-catenin binding, particularly under cellular oxidative stress conditions. Contrary to beta-catenin/TCF, beta-catenin/FOXO promotes the transcription of genes involved in cell cycle arrest and apoptosis. We have previously demonstrated that in vivo interferon-alpha2b (IFN-alpha2b) administration induces apoptosis in preneoplastic livers, a mechanism mediated by reactive oxygen species (ROS) and transforming growth factor-beta(1) (TGF-beta(1)). This study was aimed to assess the status of the Wnt/beta-catenin/TCF pathway in a very early stage of rat hepatocarcinogenesis and to further evaluate the effects of in vivo IFN-alpha2b treatment on it. We demonstrated that the Wnt/beta-catenin/TCF pathway is activated in preneoplastic rat livers. More important, in vivo IFN-alpha2b treatment inhibits Wnt/beta-catenin/TCF pathway and promotes programed cell death possibly providing a link with FOXO pathway.

Asunto(s)

Interferón-alfa/farmacología , Neoplasias Hepáticas Experimentales/metabolismo , Lesiones Precancerosas/metabolismo , Factores de Transcripción TCF/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Animales , Apoptosis/efectos de los fármacos , Humanos , Interferón alfa-2 , Masculino , Ratas , Ratas Wistar , Proteínas Recombinantes