imidapril and Cachexia

Rosiglitazone (RGZ) and imidapril improve cancer cachexia via different mechanisms. Therefore, we hypothesized that combination therapy of RGZ+imidapril would further attenuate cancer cachexia in vivo. After injection with colon-26 adenocarcinoma for 9 days, BALB/c mice were randomly divided into the following four treatment groups for 7 days (n = 8 per group): (1) placebo, (2) RGZ, (3) imidapril, and (4) RGZ+imidapril. Eight healthy control animals were also assessed. Body weight, tumor volume, gastrocnemius muscle and epididymal adipose mass, serum metabolic markers and cytokines, and the expression of nuclear factor-κB and two E3 ubiquitin ligases, atrogin-1 and MuRF-1, were measured. From days 14 to 16, all treatments significantly reduced tumor volume (P < 0.05). From days 10 to 16, improvements in the tumor-free body weight were observed in the RGZ and RGZ+imidapril groups. In addition, significant improvements in both gastrocnemius muscle and epididymal adipose mass were observed in all treatment groups (all, P < 0.05). Furthermore, all treatments significantly increased tumor necrosis factor alpha levels as compared to those observed in the healthy control animals (P < 0.001). Insulin levels significantly increased in the placebo group as compared to those in the healthy control group (P < 0.05), which were reduced in all the treatment groups (P < 0.05). Finally, whereas all treatments significantly reduced atrogin-1 levels as compared to the placebo group (all, P < 0.05), significant reductions in MuRF-1 levels were only observed in the RGZ and RGZ+imidapril groups (both, P < 0.05). Thus, all three treatments reduce tumor growth and alleviate cancer cachexia; however, synergistic effects of RGZ+imidapril combination therapy were not observed.

Topics: Adipose Tissue; Animals; Biomarkers; Body Weight; Cachexia; Cytokines; Disease Models, Animal; Drug Therapy, Combination; Gene Expression Regulation; Imidazolidines; Inflammation Mediators; Insulin; Male; Mice; Muscle Proteins; Muscles; Muscular Atrophy; Neoplasms; Organ Size; Rosiglitazone; SKP Cullin F-Box Protein Ligases; Thiazolidinediones; Tripartite Motif Proteins; Tumor Burden; Ubiquitin-Protein Ligases

Symptoms of cancer cachexia (CC) include fatigue, shortness of breath, and impaired exercise capacity, which are also hallmark symptoms of heart failure (HF). Herein, we evaluate the effects of drugs commonly used to treat HF (bisoprolol, imidapril, spironolactone) on development of cardiac wasting, HF, and death in the rat hepatoma CC model (AH-130).. Tumour-bearing rats showed a progressive loss of body weight and left-ventricular (LV) mass that was associated with a progressive deterioration in cardiac function. Strikingly, bisoprolol and spironolactone significantly reduced wasting of LV mass, attenuated cardiac dysfunction, and improved survival. In contrast, imidapril had no beneficial effect. Several key anabolic and catabolic pathways were dysregulated in the cachectic hearts and, in addition, we found enhanced fibrosis that was corrected by treatment with spironolactone. Finally, we found cardiac wasting and fibrotic remodelling in patients who died as a result of CC. In living cancer patients, with and without cachexia, serum levels of brain natriuretic peptide and aldosterone were elevated.. Systemic effects of tumours lead not only to CC but also to cardiac wasting, associated with LV-dysfunction, fibrotic remodelling, and increased mortality. These adverse effects of the tumour on the heart and on survival can be mitigated by treatment with either the β-blocker bisoprolol or the aldosterone antagonist spironolactone. We suggest that clinical trials employing these agents be considered to attempt to limit this devastating complication of cancer.

Topics: Adrenergic beta-1 Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Bisoprolol; Body Composition; Body Weight; Cachexia; Glycogen Synthase Kinase 3; Heart Failure; Imidazolidines; Liver Neoplasms; Mineralocorticoid Receptor Antagonists; Myocytes, Cardiac; Myosin Heavy Chains; Rats; Signal Transduction; Spironolactone; Survival Analysis; Ventricular Dysfunction, Left; Wasting Syndrome

The ability of angiotensin I (Ang I) and II (Ang II) to induce directly protein degradation in skeletal muscle has been studied in murine myotubes. Angiotensin I stimulated protein degradation with a parabolic dose-response curve and with a maximal effect between 0.05 and 0.1 microM. The effect was attenuated by coincubation with the angiotensin-converting enzyme (ACE) inhibitor imidaprilat, suggesting that angiotensin I stimulated protein degradation through conversion to Ang II. Angiotensin II also stimulated protein breakdown with a similar dose-response curve, and with a maximal effect between 1 and 2.5 microM. Total protein degradation, induced by both Ang I and Ang II, was attenuated by the proteasome inhibitors lactacystin (5 microM) and MG132 (10 microM), suggesting that the effect was mediated through upregulation of the ubiquitin-proteasome proteolytic pathway. Both Ang I and Ang II stimulated an increased proteasome 'chymotrypsin-like' enzyme activity as well as an increase in protein expression of 20S proteasome alpha-subunits, the 19S subunits MSS1 and p42, at the same concentrations as those inducing protein degradation. The effect of Ang I was attenuated by imidaprilat, confirming that it arose from conversion to Ang II. These results suggest that Ang II stimulates protein degradation in myotubes through induction of the ubiquitin-proteasome pathway. Protein degradation induced by Ang II was inhibited by insulin-like growth factor and by the polyunsaturated fatty acid, eicosapentaenoic acid. These results suggest that Ang II has the potential to cause muscle atrophy through an increase in protein degradation. The highly lipophilic ACE inhibitor imidapril (Vitortrade mark) (30 mg kg(-1)) attenuated the development of weight loss in mice bearing the MAC16 tumour, suggesting that Ang II may play a role in the development of cachexia in this model.

Topics: Angiotensin I; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Cachexia; Cell Culture Techniques; Imidazolidines; Male; Mice; Muscle Fibers, Skeletal; Muscle Proteins; Muscle, Skeletal; Neoplasms; Proteasome Endopeptidase Complex; Ubiquitin