RESUMO
SCOPE: Nutritional supplementation of the maternal diet can modify the cancer susceptibility in adult offspring. Therefore, the authors evaluate the effects of a fish-oil diet administered to a long-term, during pre-mating, gestation, and lactation, in reducing cancer-cachexia damages in adult Walker-256 tumor-bearing offspring. METHODS AND RESULTS: Female rats receive control or fish oil diet during pre-mating, gestation, and lactation. After weaning, male offspring are fed the control diet until adulthood and distributed in (C) control adult-offspring; (W) adult tumor-bearing offspring; (OC) adult-offspring of maternal fish oil diet; (WOC) adult tumor-bearing offspring of maternal fish oil diet groups. Fat body mass is preserved, muscle expression of mechanistic target of rapamicin (mTOR) and eukariotic binding protein of eukariotic factor 4E (4E-BP1) is modified, being associated with lower 20S proteasome protein expression, and the liver alanine aminotransferase (ALT) enzyme content maintained in the WOC group. Also, the OC group shows reduced triglyceridemia. CONCLUSION: In this experimental model of cachexia, the long-term maternal supplementation is a positive strategy to improve liver function and lipid metabolism, as well as to modify muscle proteins expression in the mTOR pathway and also reduce the 20S muscle proteasome protein, without altering the tumor development and muscle wasting in adult tumor-bearing offspring.
Assuntos
Caquexia/prevenção & controle , Carcinoma 256 de Walker/complicações , Óleos de Peixe/administração & dosagem , Alanina Transaminase/metabolismo , Animais , Composição Corporal , Carcinoma 256 de Walker/metabolismo , Suplementos Nutricionais , Feminino , Lactação , Masculino , Proteínas Musculares/metabolismo , Ratos , Ratos Wistar , Serina-Treonina Quinases TOR/fisiologia , Triglicerídeos/sangueRESUMO
CONTEXT: Cancer Pain is considered a common and significant clinical problem in malignant neoplasms, comprising 20% to 50% of all patients with tumor progression. Laser photobiomodulation (L-PBM) has been used in a multitude of pain events, ranging from acute trauma to chronic articular. However, L-PBM has never been tested in cancer pain. OBJECTIVES: Evaluate hyperalgesia, edema, COX-1, COX-2, IL-10, and Bdkrb1 mRNA in low-level laser irradiated Walker-256 tumor-bearing rats. METHODS: Rat hind paw injected with Walker Tumor-256 (W-256) and divided into six groups of 6 rats: G1 (control) - W-256 injected, G2- W-256â¯+â¯Nimesulide, G3- W-256â¯+â¯1â¯J, G4- W-256â¯+â¯3â¯Jand G5- W256â¯+â¯6â¯J. Laser parameters: λâ¯=â¯660â¯nm, 3.57â¯W/cm2, Øâ¯=â¯0.028â¯cm2. Mechanical hyperalgesia was evaluated by Randall-Selitto test. Plethysmography measured edema; mRNA levels of COX-1, COX-2, IL-10, and Bdkrb1were analyzed. RESULTS: It was found that the W-256â¯+â¯1â¯J group showed a decrease in paw edema, a significant reduction in pain threshold. Higher levels of IL-10 and lower levels of COX-2 and Bdkrb1 were observed. CONCLUSION: Results suggest that 1â¯Jâ¯L-PBM reduced the expression of COX-2 and Bdkrb1 and increasing IL-10 gene expression, promoting analgesia to close levels to nimesulide.
Assuntos
Hiperalgesia/radioterapia , Lasers Semicondutores/uso terapêutico , Terapia com Luz de Baixa Intensidade , Animais , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patologia , Linhagem Celular Tumoral , Ciclo-Oxigenase 1/genética , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Edema/metabolismo , Edema/patologia , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Masculino , Pletismografia , Ratos , Ratos Wistar , Transplante HeterólogoRESUMO
PURPOSE: The aim of this study was to investigate the effects of creatine supplementation on muscle wasting in Walker-256 tumor-bearing rats. METHODS: Wistar rats were randomly assigned into three groups (n = 10/group): control (C), tumor bearing (T), and tumor bearing supplemented with creatine (TCr). Creatine was provided in drinking water for a total of 21 days. After 11 days of supplementation, tumor cells were implanted subcutaneously into T and TCr groups. The animals' weight, food and water intake were evaluated along the experimental protocol. After 10 days of tumor implantation (21 total), animals were euthanized for inflammatory state and skeletal muscle cross-sectional area measurements. Skeletal muscle components of ubiquitin-proteasome pathways were also evaluated using real-time PCR and immunoblotting. RESULTS: The results showed that creatine supplementation protected tumor-bearing rats against body weight loss and skeletal muscle atrophy. Creatine intake promoted lower levels of plasma TNF-α and IL-6 and smaller spleen morphology changes such as reduced size of white pulp and lymphoid follicle compared to tumor-bearing rats. In addition, creatine prevented increased levels of skeletal muscle Atrogin-1 and MuRF-1, key regulators of muscle atrophy. CONCLUSION: Creatine supplementation prevents skeletal muscle atrophy by attenuating tumor-induced pro-inflammatory environment, a condition that minimizes Atrogin-1 and MuRF-1-dependent proteolysis.
Assuntos
Carcinoma 256 de Walker/metabolismo , Creatina/farmacologia , Suplementos Nutricionais , Inflamação/prevenção & controle , Atrofia Muscular/prevenção & controle , Proteólise/efeitos dos fármacos , Animais , Creatina/administração & dosagem , Modelos Animais de Doenças , Masculino , Músculo Esquelético/efeitos dos fármacos , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacosRESUMO
Leucine can stimulate protein synthesis in skeletal muscle, and recent studies have shown an increase in leucine-related mitochondrial biogenesis and oxidative phosphorylation capacity in muscle cells. However, leucine-related effects in tumour tissues are still poorly understood. Thus, we described the effects of leucine in both in vivo and in vitro models of a Walker-256 tumour. Tumour-bearing Wistar rats were randomly distributed into a control group (W; normoprotein diet) and leucine group (LW; leucine-rich diet [normoprotein + 3% leucine]). After 20 days of tumour evolution, the animals underwent 18-fludeoxyglucose positron emission computed tomography (18F-FDG PET-CT) imaging, and after euthanasia, fresh tumour biopsy samples were taken for oxygen consumption rate measurements (Oroboros Oxygraph), electron microscopy analysis and RNA and protein extraction. Our main results from the LW group showed no tumour size change, lower tumour glucose (18F-FDG) uptake, and reduced metastatic sites. Furthermore, leucine stimulated a shift in tumour metabolism from glycolytic towards oxidative phosphorylation, higher mRNA and protein expression of oxidative phosphorylation components, and enhanced mitochondrial density/area even though the leucine-treated tumour had a higher number of apoptotic nuclei with increased oxidative stress. In summary, a leucine-rich diet directed Walker-256 tumour metabolism to a less glycolytic phenotype profile in which these metabolic alterations were associated with a decrease in tumour aggressiveness and reduction in the number of metastatic sites in rats fed a diet supplemented with this branched-chain amino acid.
Assuntos
Carcinoma 256 de Walker/metabolismo , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Leucina/farmacologia , Fosforilação Oxidativa/efeitos dos fármacos , Animais , Carcinoma 256 de Walker/dietoterapia , Carcinoma 256 de Walker/patologia , Feminino , Alimentos Formulados , Metástase Neoplásica , Ratos , Ratos WistarRESUMO
The present study evaluated the in vivo antitumor effects and toxicity of a new Ru(II) compound, cis-(Ru[phen]2[ImH]2)2+ (also called RuphenImH [RuC]), against Walker-256 carcinosarcoma in rats. After subcutaneous inoculation of Walker-256 cells in the right pelvic limb, male Wistar rats received 5 or 10mgkg-1 RuC orally or intraperitoneally (i.p.) every 3 days for 13 days. A positive control group (2mgkg-1 cisplatin) and negative control group (vehicle) were also used. Tumor progression was checked daily. After treatment, tumor weight, plasma biochemistry, hematology, oxidative stress, histology, and tumor cell respiration were evaluated. RuC was effective against tumors when administered i.p. but not orally. The highest i.p. dose of RuC (10mgkg-1) significantly reduced tumor volume and weight, induced oxidative stress in tumor tissue, reduced the respiration of tumor cells, and induced necrosis but did not induce apoptosis in the tumor. No clinical signs of toxicity or death were observed in tumor-bearing or healthy rats that were treated with RuC. These results suggest that RuC has antitumor activity through the modulation of oxidative stress and impairment of oxidative phosphorylation, thus promoting Walker-256 cell death without causing systemic toxicity. These effects make RuC a promising anticancer drug for clinical evaluation.
Assuntos
Antineoplásicos/farmacologia , Carcinoma 256 de Walker/tratamento farmacológico , Complexos de Coordenação/farmacologia , Regulação Neoplásica da Expressão Gênica , Espécies Reativas de Oxigênio/agonistas , Rutênio/farmacologia , Animais , Antineoplásicos/síntese química , Carcinoma 256 de Walker/genética , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patologia , Caspase 3/genética , Caspase 3/metabolismo , Respiração Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Avaliação Pré-Clínica de Medicamentos , Injeções Subcutâneas , Masculino , Necrose/induzido quimicamente , Necrose/genética , Necrose/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Rutênio/química , Carga Tumoral/efeitos dos fármacos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Cancer cachexia is characterised by involuntary weight loss associated with systemic inflammation and metabolic changes. Studies aimed at maintaining lean body mass in cachectic tumour-bearing hosts have made important contributions reducing the number of deaths and improving the quality of life. In recent years, leucine has demonstrated effective action in maintaining lean body mass by decreasing muscle protein degradation. Currently, there is a growing need to understand how leucine stimulates protein synthesis and acts protectively in a cachectic organism. Thus, this study aimed to assess the effects of a leucine-rich diet on protein degradation signalling in muscle over the course of tumour growth. Animals were distributed into four experimental groups, which did or did not receive 2×106 viable Walker-tumour cells. Some were fed a leucine-rich diet, and the groups were subsequently sacrificed at three different time points of tumour evolution (7th, 14th, and 21st days). Protein degradation signals, as indicated by ubiquitin-proteasome subunits (11S, 19S, and 20S) and pro- and anti-inflammatory cytokines, were analysed in all experimental groups. In tumour-bearing animals without nutritional supplementation (W7, W14, and W21 groups), we observed that the tumour growth promoted a concurrent decrease in muscle protein, a sharp increase in pro-inflammatory cytokines (TNFα, IL-6, and IFNγ), and a progressive increase in proteasome subunits (19S and 20S). Thus, the leucine-supplemented tumour-bearing groups showed improvements in muscle mass and protein content, and in this specific situation, the leucine-rich diet led to an increase on the day in cytokine profile and proteasome subunits mainly on the 14th day, which subsequently had a modulating effect on tumour growth on the 21st day. These results indicate that the presence of leucine in the diet may modulate important aspects of the proteasomal pathway in cancer cachexia and may prevent muscle wasting due to the decrease in the cachexia index.
Assuntos
Carcinoma 256 de Walker/imunologia , Citocinas/sangue , Suplementos Nutricionais , Leucina/administração & dosagem , Músculo Esquelético/metabolismo , Proteínas/metabolismo , Animais , Composição Corporal , Caquexia/sangue , Caquexia/imunologia , Carcinoma 256 de Walker/metabolismo , Citocinas/biossíntese , Citocinas/imunologia , Dieta , Inflamação , Interleucina-4/sangue , Interleucina-6/sangue , Músculo Esquelético/química , Biossíntese de Proteínas , Qualidade de Vida , Ratos , Ratos WistarRESUMO
The aim of this study was to investigate the effects of resistance exercise training (RET) on oxidative stress, systemic inflammatory markers, and muscle wasting in Walker-256 tumor-bearing rats. Male (Wistar) rats were divided into 4 groups: sedentary controls (n = 9), tumor-bearing (n = 9), exercised (n = 9), and tumor-bearing exercised (n = 10). Exercised and tumor-bearing exercised rats were exposed to resistance exercise of climbing a ladder apparatus with weights tied to their tails for 6 weeks. The physical activity of control and tumor-bearing rats was confined to the space of the cage. After this period, tumor-bearing and tumor-bearing exercised animals were inoculated subcutaneously with Walker-256 tumor cells (11.0 × 107 cells in 0.5 mL of phosphate-buffered saline) while control and exercised rats were injected with vehicle. Following inoculation, rats maintained resistance exercise training (exercised and tumor-bearing exercised) or sedentary behavior (control and tumor-bearing) for 12 more days, after which they were euthanized. Results showed muscle wasting in the tumor-bearing group, with body weight loss, increased systemic leukocytes, and inflammatory interleukins as well as muscular oxidative stress and reduced mTOR signaling. In contrast, RET in the tumor-bearing exercised group was able to mitigate the reduced body weight and muscle wasting with the attenuation of muscle oxidative stress and systemic inflammatory markers. RET also prevented loss of muscle strength associated with tumor development. RET, however, did not prevent the muscle proteolysis signaling via FBXO32 gene messenger RNA expression in the tumor-bearing group. In conclusion, RET performed prior tumor implantation prevents cachexia development by attenuating tumor-induced systemic pro-inflammatory condition with muscle oxidative stress and muscle damage.
Assuntos
Caquexia/prevenção & controle , Carcinoma 256 de Walker/terapia , Leucocitose/prevenção & controle , Debilidade Muscular/prevenção & controle , Músculo Esquelético/fisiopatologia , Estresse Oxidativo , Condicionamento Físico Animal , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Caquexia/etiologia , Caquexia/imunologia , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patologia , Carcinoma 256 de Walker/fisiopatologia , Citocinas/sangue , Regulação Neoplásica da Expressão Gênica , Mediadores da Inflamação/sangue , Leucocitose/etiologia , Leucocitose/imunologia , Masculino , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Debilidade Muscular/etiologia , Debilidade Muscular/imunologia , Músculo Esquelético/imunologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distribuição Aleatória , Ratos Wistar , Proteínas Ligases SKP Culina F-Box/genética , Proteínas Ligases SKP Culina F-Box/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Carga Tumoral , Aumento de Peso , Redução de PesoRESUMO
The purpose of this study was to establish a population pharmacokinetic/pharmacodynamic (PK/PD) model linking etoposide free tumor and total plasma concentrations to the inhibition of solid tumor growth in rats. Walker-256 tumor cells were inoculated subcutaneously in the right flank of Wistar rats, which were randomly divided in control and two treated groups that received etoposide 5 or 10mg/kg i.v. bolus every day for 8 and 4days, respectively, and tumor volume was monitored daily for 30days. The plasma and intratumoral concentrations-time profiles were obtained from a previous study and were modeled by a four-compartment population pharmacokinetic (popPK) model. PK/PD analysis was conducted using MONOLIX v.4.3.3 on average data and by mean of a nonlinear mixed-effect model. PK/PD data were analyzed using a modification of Simeoni Tumor Growth Inhibition (TGI) model by introduction of an Emax function to take into account the concentration dependency of k2variable parameter (variable potency). The Simeoni TGI-Emax model was capable to fit schedule-dependent antitumor effects using the tumor growth curves from the control and two different administered schedules. The PK/PD model was capable of describing the tumor growth inhibition using total plasma or free tumor concentrations, resulting in higher k2max (maximal potency) for free concentrations (25.8mL·µg-1·day-1 - intratumoral vs. 12.6mL·µg-1·day-1 total plasma). These findings indicate that the plasma concentration may not be a good surrogate for pharmacologically active free tumor concentrations, emphasizing the importance of knowing drug tumor penetration to choose the best antitumor therapy.
Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Carcinoma 256 de Walker/metabolismo , Modelos Animais de Doenças , Etoposídeo/farmacocinética , Inibidores do Crescimento/farmacocinética , Carga Tumoral/efeitos dos fármacos , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma 256 de Walker/tratamento farmacológico , Carcinoma 256 de Walker/patologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Etoposídeo/uso terapêutico , Inibidores do Crescimento/uso terapêutico , Masculino , Ratos , Ratos Wistar , Carga Tumoral/fisiologiaRESUMO
BACKGROUND: Cachexia is a significant problem in patients with cancer. The effect of cancer on interstitial cells of Cajal (ICC) and neurons of the gastrointestinal tract have not been studied previously. Although supplementation with L-glutamine 2% may have beneficial effects in cancer-related cachexia, and be protective of ICC in models of oxidative stress such as diabetes, its effects on ICC in cancer have also not been studied. METHODS: Twenty-eight male Wistar rats were divided into four groups: control (C), control supplemented with L-glutamine (CG), Walker 256 tumor (WT), and Walker 256 tumor supplemented with L-glutamine (WTG). Rats were implanted with tumor cells or injected with saline in the right flank. After 14 days, the jejunal tissues were collected and processed for immunohistochemical techniques including whole mounts and cryosections and Western blot analysis. KEY RESULTS: Tumor-bearing rats demonstrate reduced numbers of Myenteric ICC and deep muscular plexus ICC and yet increased Ano1 protein expression and enhanced ICC networks. In addition, there is more nNOS protein expressed in tumor-bearing rats compared to controls. L-glutamine treatment had a variety of effects on ICC that may be related to the disease state and the interaction of ICC and nNOS neurons. Regardless, L-glutamine reduced the size of tumors and also tumor-induced cachexia that was not due to altered food intake. CONCLUSIONS & INFERENCES: There are significant effects on ICC in the Walker 256 tumor model. Although supplementation with L-glutamine has differential and complex effects of ICC, it reduces tumor size and tumor-associated cachexia, which supports its beneficial therapeutic role in cancer.
Assuntos
Caquexia/metabolismo , Carcinoma 256 de Walker/metabolismo , Canais de Cloreto/efeitos dos fármacos , Glutamina/farmacologia , Células Intersticiais de Cajal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Plexo Mientérico/efeitos dos fármacos , Óxido Nítrico Sintase Tipo I/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Anoctamina-1 , Western Blotting , Carcinoma 256 de Walker/patologia , Canais de Cloreto/metabolismo , Imuno-Histoquímica , Células Intersticiais de Cajal/metabolismo , Masculino , Plexo Mientérico/citologia , Óxido Nítrico Sintase Tipo I/metabolismo , Ratos , Ratos Wistar , Carga TumoralRESUMO
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.