Study of Walter 256 tumour growth in young and adults rats treated with eisosapentaenoic acid (EPA)

Author(s)

Tatiane Pertile

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2011-12-08

Examining board members

Maria Cristina Cintra Gomes Marcondes; Dora Maria Grassi Kassisse; Estela Maria Gonçalves

• Advisor: Maria Cristina Cintra Gomes Marcondes

Abstract

Cancer can promotes the host death, because during its evolution there are modifications in metabolic processes of homeostasis, promoting deep changes characterized as cachexia, which in turn relates with reduction in quality and lifetime of the host. Thus, in this study, we analyze the effects of development in Walker 256 carcinoma evolution - in young and adults rats and the modulatory effect of treatment with EPA (eicosapentaenoic acid) in gastrocnemius muscle as this tissue is the most affected in the cachexia process. Wistar males rats were used (n=108 animals), 30 days-old (young) and 100 days-old (adults), which were distributed according to the tumour implant, intraperitoneally and subcutaneously and treatment or not with eicosapentaenoic acid, 100 ?g/Kg of body weight. The animals receive daily EPA by gavage (treated animals) or nujol (sham groups) and were cared up to pre-agonic state. The bodies weight were measured and the body weight gain was calculated, as well the relative weights of tissues, tumour, and carcass. In order to identify the predominant pathway of protein degradation the total muscle protein content and proteolytic enzymes activities (chymotrypsin-like, cathepsin B and H, calpain and alkaline phosphatase) were measured in gastrocnemius muscle. The blood samples were assessed to measure the insulin-like growth factor 1 (IGF-1), leptin and the cytokines - interleukins (IL-4), 6 (IL-6) and 10 (IL-10), gamma interferon (INF-?), using specific kits for cytometer fluorescence (Luminex). It was also examined gene expression, in the muscle tissue, by real-time polymerase chain reaction (RT-PCR), assessing keys of ubiquitin-proteasome pathway and also on the eukaryotic initiation factors. The data indicated some modulatory effects of EPA on the muscle tissue (maintenance of protein and weight), mainly for the young rats, and also the chronic inflammatory process. However, more expressive effects of EPA have not been verified as preventing fat wasting (perirenal fat and leptin), nor in the process of protein synthesis (maintenance of eukaryotic initiating factors gene expression) or also in the ubiquitin-proteasome via (AU)

• FAPESP's process: 09/03209-2 - Molecular and biochemistry aspects of cancer-cachexia in weaning and adult rats
• Grantee: Tatiane Pertile
• Support Opportunities: Scholarships in Brazil - Master