Cachectic Tumour-bearing Rats Research Articles

A multifactorial anti-cachectic approach for cancer cachexia in a rat model undergoing chemotherapy.

BackgroundThe effectiveness of drugs aimed at counteracting cancer cachexia is generally tested in pre‐clinical rodent models, where only the tumour‐induced alterations are taken into account, excluding the co‐presence of anti‐tumour molecules that could worsen the scenario and/or interfere with the treatment.MethodsThe aim of the present investigation has been to assess the efficacy of a multifactorial treatment, including formoterol and megestrol acetate, in cachectic tumour‐bearing rats (Yoshida AH‐130, a highly cachectic tumour) undergoing chemotherapy (sorafenib).ResultsTreatment of cachectic tumour‐bearing rats with sorafenib (90 mg/kg) causes an important decrease in tumour cell content due to both reduced cell proliferation and increased apoptosis. As a consequence, animal survival significantly improves, while cachexia occurrence persists. Multi‐factorial treatment using both formoterol and megestrol acetate is highly effective in preventing muscle wasting and has more powerful effects than the single formoterol administration. In addition, both physical activity and grip strength are significantly improved as compared with the untreated tumour‐bearing animals. The effects of the multi‐factorial treatment include increased food intake (likely due to megestrol acetate) and decreased protein degradation, as shown by the reduced expression of genes associated with both proteasome and calpain proteolytic systems.ConclusionsThe combination of the two drugs proved to be a promising strategy for treating cancer cachexia in a pre‐clinical setting that better resembles the human condition, thus providing a strong rationale for the use of such combination in clinical trials involving cachectic cancer patients.

Formoterol in the treatment of experimental cancer cachexia: effects on heart function.

Background and aimsFormoterol is a highly potent β2-adrenoceptor-selective agonist, which is a muscle growth promoter in many animal species, resulting in skeletal muscle hypertrophy. Previous studies carried out in our laboratory have shown that formoterol treatment in tumour-bearing animals resulted in an amelioration of muscle loss through different mechanisms that include muscle apoptosis and proteolysis.MethodsThe study presented involved rats bearing the Yoshida AH-130 ascites tumour model—which induces a high degree of cachexia—treated with the beta-2 agonist formoterol (0.3 mg/kg BW).ResultsThe administration of formoterol to cachectic tumour-bearing rats resulted in a significant reduction of muscle weight loss. The treatment also increased lean body mass and body water. The treatment, however, did not influence heart weight, which was much decreased as a result of tumour burden. Untreated tumour-bearing rats showed important changes in parameters related with heart function:, left ventricle (LV) ejection fraction, fractional shortening, LV diameter and volume (diastolic) and LV stroke volume, LV mass and posterior wall thickness (PWT) (both systolic and diastolic). The administration of formoterol affected LV diameter and volume, LV stroke volume and LV mass.ConclusionsThe results suggest that formoterol treatment, in addition to reducing muscle wasting, does not negatively alter heart function—in fact, some cardiac parameters are improved—in animals affected by cancer cachexia.

Megestrol acetate treatment influences tissue amino acid uptake and incorporation during cancer cachexia

Summary Background & aims Cachexia is a multi-organic syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting and inflammation, being often associated with anorexia. The aim of the present investigation was to study the effects of megestrol acetate (MA) on the rate of leucine incorporation into muscle tissue and on the uptake of AIB (a non-metabolizable analogue of alanine) in both skeletal muscle and liver tissue. Methods The effects of MA (100 mg/kg) were tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Tissue amino acid uptake was assessed by means of the alanine analogue α-amino-3H-isobutyrate (AIB). 14C-leucine oxidation and tissue protein incorporation were also determined. Results Administration of MA to tumour-bearing rats resulted in an important reversal of the muscle wasting process, as reflected by individual muscle weights. Treatment with the progestogen resulted in an increased AIB uptake together with an increased leucine incorporation in skeletal muscle. MA treatment significantly decreased AIB uptake by the liver. Conclusions MA treatment results in both a significant increased uptake of neutral amino acids (AIB) by skeletal muscle and a significant incorporation of the branched-chain amino acid leucine into muscle protein, indicating a clear anabolic action of the drug on muscle tissue.

Formoterol treatment downregulates the myostatin system in skeletal muscle of cachectic tumour-bearing rats

Cachexia is a common systemic manifestation. Additionally, myostatin is known to be a negative regulator of skeletal muscle development. The present study aimed to investigate whether formoterol down-regulates the myostatin system in skeletal muscle of tumour-bearing rats. Real-time PCR and Western blotting were used for the analysis. Results showed that rats bearing the Yoshida AH-130 ascites hepatoma, a cachexia-inducing tumour, exhibited marked muscle wasting that affected the mass of the muscles studied. The cachectic animals exhibited a significant increase in the mRNA levels of the myostatin receptor (ActIIB) in gastrocnemius muscles. Notably, the expression of the various forms of follistatin, a protein with the opposite effects to those of myostatin, was significantly reduced as a result of the implantation of the tumour. When the animals were treated with formoterol, a β-agonist with anti-cachectic potential, increases in skeletal muscle weights were observed. The β-agonist significantly increased levels of various follistatin isoforms and significantly decreased the expression levels of the myostatin receptor. In addition, formoterol treatment resulted in a significant decrease of the myostatin protein content of the gastrocnemius muscle. In conclusion, the results presented indicate that certain anabolic actions of formoterol on the skeletal muscle of cachectic animals may be mediated via the myostatin system.

L-Carnitine induces recovery of liver lipid metabolism in cancer cachexia

Cancer cachexia causes metabolic alterations with a marked effect on hepatic lipid metabolism. L-Carnitine modulates lipid metabolism and its supplementation has been proposed as a therapeutic strategy in many diseases. In the present study, the effects of L-carnitine supplementation on gene expression and on liver lipid metabolism-related proteins was investigated in cachectic tumour-bearing rats. Wistar rats were assigned to receive 1 g/kg of L-carnitine or saline. After 14 days, supplemented and control animals were assigned to a control (N), control supplemented with L-carnitine (CN), tumour-bearing Walker 256 carcinosarcoma (TB) and tumour-bearing supplemented with L-carnitine (CTB) group. The mRNA expression of carnitine palmitoyltransferase I and II (CPT I and II), microsomal triglyceride transfer protein (MTP), liver fatty acid-binding protein (L-FABP), fatty acid translocase (FAT/CD36), peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and organic cation transporter 2 (OCTN2) was assessed, and the maximal activity of CPT I and II in the liver measured, along with plasma and liver triacylglycerol content. The gene expression of MTP, and CPT I catalytic activity were reduced in TB, who also showed increased liver (150%) and plasma (3.3-fold) triacylglycerol content. L-Carnitine supplementation was able to restore these parameters back to control values (p<0.05). These data show that L-carnitine preserves hepatic lipid metabolism in tumour-bearing animals, suggesting its supplementation to be of potential interest in cachexia.

Sirtuin 1 in skeletal muscle of cachectic tumour‐bearing rats: a role in impaired regeneration?

Background:In advanced malignant disease, cachexia and muscle wasting appear to be among the most common manifestations. This phenomenon is partially related with a decreased muscle regeneration capacity, as previously described in our laboratory.Methods and results:Rats bearing the Yoshida AH-130 ascites hepatoma were used in the experiments. The animals experienced a marked weight loss with decreases in skeletal muscle weights (13% gastrocnemius, 18% extensor digitorum longus, and 12% tibialis muscles). Muscle gene expression was measured using real-time polymerase chain reaction. Skeletal muscle from cachectic tumour-bearing rats is associated with a decreased expression of genes involved in regeneration such as Pax-7 (39%), myogenin (24%), and MyoD (17%). mRNA levels of Sirt1 increased (91%) in cachectic skeletal muscle. The Sirt1 gene has been shown to be associated with changes in muscle myoblast differentiation. Treatment of the tumour-bearing animals with formoterol—a beta2-agonist—normalizes the expression of genes involved in regeneration (i.e., increase of Pax7 (139%)), at the same time as it does with that of Sirt1 (42% decrease).Conclusions:It is suggested that the lack of muscle regeneration observed during muscle wasting in tumour-bearing animals is linked to the action of Sirt-1, possibly via PGC-1α. These factors may constitute possible targets of pharmacological treatment against muscle loss, thus potentially contributing to the understanding and mitigation of muscle atrophy associated with disease.

Formoterol May Activate Rat Muscle Regeneration During Cancer Cachexia

PURPOSE: The development of cancer cachexia is the most common manifestation of advanced malignant disease. METHOD: The effects on muscle regeneration of β2�adrenoceptor agonist formoterol (0.3 mg/kg) were tested in cachectic tumourbearing rats (Yoshida AH�130 ascit es hepatoma). RESULTS: Administration of formoterol results in a significant increase in the mass and protein content of tibialis muscle in tumourbearin grats. This increase is associated with a decreased myogenin mRNA content together with an increased Pax�7 gene expression. Bupivacaine treatment by local injection results in an important reduction in tibialis weight together with significant increases in Pax�7, myogenin and MyoD gene expression. Formoterol treatment in bupivacainetreated rats results in significant increases in Pax�7 together with significant decreases in myogenin mRNA content, suggesting that this β2�agonist is favouring muscle regeneration by stimulating the proliferation of satellite cells. Altogether, the data reinforce the potential role of formoterol in the treatment of muscle wasting diseases.

Nutraceutical inhibition of muscle proteolysis: A role of diallyl sulphide in the treatment of muscle wasting

The abnormalities associated with cancer cachexia include anorexia, weight loss, muscle loss and atrophy, anaemia and alterations in carbohydrate, lipid and protein metabolism. The aim of the present investigation was to examine the anti-wasting effects of some nutraceuticals such as genistein, resveratrol, epigallocatechin gallate and diallyl sulphide (DAS). The in vitro effects of these nutraceuticals on proteolysis were examined in muscle cell cultures submitted to hyperthermia. The in vivo effects of DAS were also tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Although all the nutraceuticals tested inhibited muscle proteolysis, the most promising effects were related with DAS. In vivo administration of DAS only leads to a small improvement in tibialis muscle and heart weights; however, administration of DAS to healthy animals increased all muscle weights, this being associated with a decreased gene expression of proteolytic systems components. It may be suggested that DAS could be used to improve muscle mass during healthy conditions.

Megestrol acetate: Its impact on muscle protein metabolism supports its use in cancer cachexia

Cachexia is a multiorganic syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting and inflammation, being often associated with anorexia. The aim of the present investigation was to examine the effect of megestrol acetate (MA) in cachectic tumour-bearing animals analyzing changes in muscle proteolysis and in parameters related with quality of life. The effects of MA (100mg/kg) were tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Administration of MA to tumour-bearing rats resulted in an important reversal of the muscle wasting process, as reflected by individual muscle weights. MA also decreased the rate of protein degradation in incubated isolated skeletal muscles. Real-time PCR analysis revealed that MA treatment resulted in a decrease in ubiquitin, E2 and atrogin-1 mRNA content in muscles, therefore suggesting that the main anti-proteolytic action of the drug may be based on an inhibition of the ATP-ubiquitin-dependent proteolytic system. The drug also improves appetite, weight loss, total physical activity and grip force. The results indicate that treatment with megestrol acetate increases appetite, weight loss, physical performance and muscle force in tumour-bearing rats suggesting that MA is a good candidate for muscle wasting treatment.

Effect of endurance training upon lipid metabolism in the liver of cachectic tumour‐bearing rats

The syndrome of cancer cachexia is accompanied by several alterations in lipid metabolism, and the liver is markedly affected. Previous studies showed that moderate exercise training may prevent liver fat accumulation through diminished delivery of lipids to the liver, increased hepatic oxidation and increased incorporation of triacylglycerol (TAG) into very low density lipoprotein (VLDL). Our aim was to examine the influence of moderate intensity training (8 weeks) upon TAG content, VLDL assembly and secretion, apolipoprotein B (apoB) and microsomal transfer protein (MTP) gene expression in the liver of cachectic tumour-bearing rats. Animals were randomly assigned to a sedentary control (SC), sedentary tumour-bearing (ST) or exercise-trained control (EC) or to an exercise trained tumour-bearing (ET) group. Trained rats ran on a treadmill (60% VO(2max)) for 60 min day(-1), 5 day week(-1), for 8 weeks. TAG content and the rate of VLDL secretion (followed for 3 h), as well as mRNA expression of apoB and MTP, and total cholesterol, VLDL-TAG, VLDL-cholesterol, high density lipoprotein cholesterol (HDL-cholesterol) and tumour weight were evaluated. VLDL-cholesterol showed a decrease in ST (p < 0.05) in relation to SC. Serum TAG, VLDL-TAG and tissue TAG content were all increased in ST (p < 0.01), when compared with SC. ST showed a lower rate of VLDL secretion (p < 0.05) and reduced expression of apoB (p < 0.001) and MTP (p < 0.001), when compared with SC. These parameters were restored to control values (p < 0.05) when the animals were submitted to the exercise training protocol. Tumour weight decreased 10-fold after training (p < 0.001). It is possible to affirm, therefore, that endurance training promoted the re-establishment of lipid metabolism in cachectic tumour-bearing animals, especially in relation to VLDL secretion and assembly.

The AP-1/NF-κB double inhibitor SP100030 can revert muscle wasting during experimental cancer cachexia

Daily treatment of rats bearing the cachectic Yoshida AH-130 ascites hepatoma with the double inhibitor of NF-kappaB and AP-1 SP100030 at a dose of 1 mg/kg of body weight resulted in a clear amelioration of the cachectic effect, especially at the level of skeletal muscle. Thus, tumour-bearing rats treated with SP100030 showed a significant recovery in the weights of gastrocnemius, EDL, tibialis and cardiac muscles. In addition, treatment with the inhibitor affected both liver and kidney weights. The amelioration in muscle weight was accompanied by an increase in MyoD gene expression, the main transcription factor of muscle tissue involved in muscle differentiation, in gastrocnemius muscle. At the dose used in this study, SP100030 was an effective inhibitor of AP-1; however, the NF-kappaB transcription factor was not affected. The effects of the inhibitor seem to be at the level of proteolysis since lower total proteolytic rates were found when incubating isolated rat muscles in the presence of SP100030. The inhibitor influenced the gene expression of the ubiquitin-conjugating enzyme E214K in skeletal muscle of tumour-bearing rats; this enzyme seems to be the main regulator of the activity of the main proteolytic system involved during cancer cachexia, the ubiquitin-proteasome system. In conclusion, treatment of cachectic tumour-bearing rats with SP100030 results in an amelioration of the muscle wasting effect, suggesting that the AP-1 signaling cascade plays an important role in the signaling of muscle wasting associated with disease.

Day-night pattern of energy expenditure and body temperature in cachectic tumour-bearing rats.

The implication of an increase in energy expenditure in cancer cachexia, which seems to be related to the type of tumour, remains unclear. We therefore investigated the energy metabolism and body temperature in anorectic and cachectic rats bearing the Yoshida sarcoma (TB), in comparison with pair-fed (PF) and ad-libitum fed (AL) control rats. The resting energy expenditure was higher in the TB than in the two control groups when corrected for the modifications of body composition. However, the total energy expenditure did not differ between the TB and the AL, presumably because of the drop of activity in TB. There was a temporal distribution of differences in energy expenditure with higher energy expenditure in TB than in AL during the diurnal phase and a lack of difference during the nocturnal phase. The TB presented a fever, which was limited to the diurnal period. Moreover, the acrophase of the body temperature rhythm was delayed in the TB. These results highlight the circadian effects of tumour development on the energy metabolism of the host and hint to the possible implication of cytokines. © 2000 Harcourt Publishers Ltd © 2000 Cancer Research Campaign