RESUMEN
BACKGROUND: Several studies have been shown pro-apoptotic effects of fish oil (FO), rich in n-3 polyunsaturated fatty acids (n-3 PUFA) on cancer cells. Nevertheless, few in vivo experiments have provided data of its ability on apoptosis protein expression in tumor tissue. Thus, in this study we investigate the effect of FO supplementation on apoptosis protein expression in Walker 256 tumor bearing rats. Male Wistar rats were randomly assigned to three groups: fed with regular chow (W); fed regular chow supplemented with FO (WFO) or coconut fat (WCO) (1 g/kg body weight/daily). After thirty days, all animals were inoculated subcutaneously with Walker 256 tumor cells. FINDINGS: Protein expression was done by western blotting in Walker 256 tumor tissue samples. FO decreased the Bcl-2/Bax ratio (p < 0.05) and increased the p53 (p < 0.05), cleaved caspase-7 (p < 0.05) and cleaved caspase-3 (p < 0.05) in Walker 256 tumor tissue. CONCLUSIONS: Our data suggest that the pro-apoptotic effect of FO in Walker 256 tumor is related with specifics cleaved caspases.
Asunto(s)
Anticarcinógenos/farmacología , Carcinoma 256 de Walker/dietoterapia , Suplementos Dietéticos , Aceites de Pescado/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Carcinoma 256 de Walker/genética , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patología , Caspasa 3/genética , Caspasa 3/metabolismo , Caspasa 7/genética , Caspasa 7/metabolismo , Aceite de Coco , Inyecciones Subcutáneas , Masculino , Aceites de Plantas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Wistar , Transducción de Señal , Carga Tumoral/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
We investigated the effect of chronic supplementation with shark liver oil (SLO), an antitumor supplement source of n-3 fatty acids and 1-O-alkylglycerols, alone and combined with coconut fat (CF), a source of saturated fatty acids, on Walker 256 tumor growth and cachexia. Male rats were supplemented daily and orally with SLO and/or CF (1 g per kg body weight) for 7 wk. After 7 wk, 50% of animals were subcutaneously inoculated with 3 × 10(7) Walker 256 tumor cells. After 14 days, the rats were killed, the tumors were removed for lipid peroxidation measurement, and blood was collected for glycemia, triacylglycerolemia, and lacticidemia evaluation. Liver samples were obtained for glycogen measurement. Unlike CF, supplementation with SLO promoted gain in body weight, reduction of tumor weight, and maintained glycemia, triacylglycerolemia, lacticidemia, and liver glycogen content to values similar to non-tumor-bearing rats. Combined supplementation of SLO with CF also showed a reversion of cachexia with gain in body mass, reduction of lacticidemia, maintaining the liver glycogen store, and reduction in tumor weight. SLO, alone or combined with CF, promoted increase of tumor lipid peroxidation. In conclusion, SLO supplemented chronically, alone or associated with CF, was able to reduce tumor growth and cachexia.