Cancer-induced cachexia involves weight loss, catabolic activity, and inflammation. We have evaluated the effects of various treatments (GH, insulin (INS), indomethacin (IND), and all possible combinations) on cancer cachexia in a mouse model. BALB/c mice that were implanted with colon-26 adenocarcinoma developed cachexia in 9 days. Body weight, tumor volume, tumor-free weight, inflammatory cytokines (tumor necrosis factor-a (TNF-a), interleukin 6 (IL6)), and nutritional markers (glucose (Glu), albumin, triglycerides (TGs)) of treatment and control groups were monitored. In the cachexia group, there was a significant decrease in tumor-free bodyweight by day 11. Treatment with GHCINSCIND significantly alleviated tumor-free bodyweight reduction and cachexiainduced changes in nutritional markers and cytokines, and prolonged survival time. GHCINSCIND treatment was more effective than other treatment combinations in elevating Glu and TGs, reducing TNF-a and IL6 levels, and prolonging survival time. In conclusion, GHCINS CIND alleviated cachexia symptoms in a murine model of cancer cachexia.

Cancer-related cachexia involves increased protein breakdown through various proteolytic pathways, including the ubiquitin-proteasome pathway (UPP). We hypothesized that a calcium- and calpain-dependent pathway might play a crucial role during the proteolytic procedure, and that pathway interventions would ameliorate cancer cachexia in vivo. After being inoculated with CT26 adenocarcinoma cell culture subcutaneously, BALB/c mice developed cachexia in 12 days. They were then administered with different types of calpain inhibitors individually or in combination for 7 consecutive days. Eighteen healthy mice were also assessed as a control group. Changes in body weight, gastrocnemius muscle mass, tumor volume, food intake, survival time, and serum nutritional markers were monitored. Also measured were the levels of calpains, E3 ubiquitin ligases, and apoptosis-associated markers in gastrocnemius muscle. Our study showed that the intraperitoneal administration of calpain inhibitors significantly improved tumor-free body weight and gastrocnemius muscle mass in all treatment groups. Treatment with calpain inhibitors also ameliorated cachexia-associated negative effects in metabolic profiles and increased survival time in most of the tumor-bearing mice compared with the cachexia controls. Furthermore, calpain inhibitors reduced the calpain activity and the expression of MuRF-1 and atrogin-1 in all treatment groups, while increasing the level of cleaved caspase-3 and BAX and lowering the level of BCL-2 in some groups. These results justify further evaluation of calpain inhibitors both alone and in combination with other candidate agents as a potential new therapeutic strategy for treating cancer cachexia.

Cancer cachexia is a life‑threatening syndrome associated with myofiber damage. Tumor factors impair muscle regeneration by promoting myoblast apoptosis. Ghrelin is a multifunctional hormone with an anti‑apoptotic effect, but its mechanism of action is not fully understood. In the present study, we investigated whether the coculturing of C2C12 myoblasts with CT26 colon carcinoma cells may induce myoblast apoptosis, and whether acylated ghrelin (AG) and unacylated ghrelin (UnAG) may exert anti‑apoptotic effects. We found that the coculture induced myoblast apoptosis and increased tumor necrosis factor (TNF)‑α concentrations in the culture medium. Moreover, the coculture increased c‑Jun N‑terminal kinase (JNK) activity, suppressed Akt activity, increased the mitochondrial Bax/Bcl‑2 ratio, impaired mitochondrial membrane potential (Δψm), increased the cytosolic cytochrome c levels, and activated the caspase‑3/poly (ADP‑ribose) polymerase (PARP) cascade in myoblasts. We also found that either AG or UnAG inhibited these changes. The present study describes a novel in vitro model that can be employed to investigate cancer‑induced myoblast apoptosis, and our findings suggest a possible use for AG and UnAG in treating cancer cachexia.

Cancer cachexia is a result of increased protein degradation and decreased protein synthesis. The multifunctional circulating hormone ghrelin promotes synthesis and inhibits degradation of muscle protein, but its mechanism of action is not fully understood. Here, we investigated whether co-culturing C2C12 myotubes with CT26 colon carcinoma cells induces myotube atrophy, and whether acylated ghrelin (AG) and unacylated ghrelin (UnAG) had anti-atrophic effects. We found that co-culture induced myotube atrophy and increased tumor necrosis factor-alpha (TNF-α) and myostatin concentrations in the culture medium. Moreover, co-culture down-regulated myogenin and MyoD expression, inhibited the Akt signaling, up-regulated ubiquitin E3 ligase expression, and activated the calpain system and autophagy in myotubes. Both AG and UnAG inhibited these changes. Our study describes a novel in vitro model that can be employed to investigate cancer cachexia, and our findings suggest a possible use for AG and UnAG in treating cancer 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.