Energy metabolism in cachexia

Epigallocatechin gallate protects against fat and muscle atrophy in B16BL6 melanoma-bearing mice on a high-fat diet

AIMS

Epidemiological evidence indicates that there is a substantial association between body mass index (BMI) and at least ten forms of cancer, including melanoma, and BMI imbalance contributes to the poor survival rate of cancer patients before and after therapy. Nevertheless, few pharmacological studies on models of obesity and cancer have been reported. In this study, we administered epigallocatechin gallate (EGCG) to B16BL6 tumor-bearing mice that received a high-fat diet (HFD) to examine its impact.

METHODS

B16BL6 tumor-bearing mice were fed a HFD. Body weight and food intake were documented every week. We conducted a Western blot analysis to examine the protein levels in the tumor, gastrocnemius (GAS), and tibialis anterior (TA) muscles, as well as the inguinal and epididymal white adipose tissues (iWAT and eWAT).

KEY FINDINGS

EGCG has been shown to have anti-cancer effects equivalent to those of cisplatin, a chemotherapy drug. Furthermore, EGCG protected against the loss of epidydimal white adipose tissue by regulating protein levels of lipolysis factors of adipose triglyceride lipase and hormone-sensitive lipase as well as WAT browning factors of uncoupling protein 1, as opposed to cisplatin. EGCG was shown to reduce the protein levels of muscular atrophy factors of muscle RING-finger protein-1, whereas cisplatin did not contribute to rescuing the atrophy of TA and GAS muscles.

CONCLUSION

Taken together, our findings indicate that EGCG has a preventive effect against cachexia symptoms and has anti-cancer effects similar to those of cisplatin in tumor-bearing mice fed a high-fat diet.

Futile cycles: Emerging utility from apparent futility

Futile cycles are biological phenomena where two opposing biochemical reactions run simultaneously, resulting in a net energy loss without appreciable productivity. Such a state was presumed to be a biological aberration and thus deemed an energy-wasting "futile" cycle. However, multiple pieces of evidence suggest that biological utilities emerge from futile cycles. A few established functions of futile cycles are to control metabolic sensitivity, modulate energy homeostasis, and drive adaptive thermogenesis. Yet, the physiological regulation, implication, and pathological relevance of most futile cycles remain poorly studied. In this review, we highlight the abundance and versatility of futile cycles and propose a classification scheme. We further discuss the energetic implications of various futile cycles and their impact on basal metabolic rate, their bona fide and tentative pathophysiological implications, and putative drug interactions.

Metabolomics-driven discovery of therapeutic targets for cancer cachexia

Cancer cachexia (CC) is a devastating metabolic syndrome characterized by skeletal muscle wasting and body weight loss, posing a significant burden on the health and survival of cancer patients. Despite ongoing efforts, effective treatments for CC are still lacking. Metabolomics, an advanced omics technique, offers a comprehensive analysis of small-molecule metabolites involved in cellular metabolism. In CC research, metabolomics has emerged as a valuable tool for identifying diagnostic biomarkers, unravelling molecular mechanisms and discovering potential therapeutic targets. A comprehensive search strategy was implemented to retrieve relevant articles from primary databases, including Web of Science, Google Scholar, Scopus and PubMed, for CC and metabolomics. Recent advancements in metabolomics have deepened our understanding of CC by uncovering key metabolic signatures and elucidating underlying mechanisms. By targeting crucial metabolic pathways including glucose metabolism, amino acid metabolism, fatty acid metabolism, bile acid metabolism, ketone body metabolism, steroid metabolism and mitochondrial energy metabolism, it becomes possible to restore metabolic balance and alleviate CC symptoms. This review provides a comprehensive summary of metabolomics studies in CC, focusing on the discovery of potential therapeutic targets and the evaluation of modulating specific metabolic pathways for CC treatment. By harnessing the insights derived from metabolomics, novel interventions for CC can be developed, leading to improved patient outcomes and enhanced quality of life.

Coculture with Colon-26 cancer cells decreases the protein synthesis rate and shifts energy metabolism toward glycolysis dominance in C2C12 myotubes

Cancer cachexia is the result of complex interorgan interactions initiated by cancer cells and changes in patient behavior such as decreased physical activity and energy intake. Therefore, it is crucial to distinguish between the direct and indirect effects of cancer cells on muscle mass regulation and bioenergetics to identify novel therapeutic targets. In this study, we investigated the direct effects of Colon-26 cancer cells on the molecular regulating machinery of muscle mass and its bioenergetics using a coculture system with C2C12 myotubes. Our results demonstrated that coculture with Colon-26 cells induced myotube atrophy and reduced skeletal muscle protein synthesis and its regulating mechanistic target of rapamycin complex 1 signal transduction. However, we did not observe any activating effects on protein degradation pathways including ubiquitin-proteasome and autophagy-lysosome systems. From a bioenergetic perspective, coculture with Colon-26 cells decreased the complex I-driven, but not complex II-driven, mitochondrial ATP production capacity, while increasing glycolytic enzyme activity and glycolytic metabolites, suggesting a shift in energy metabolism toward glycolysis dominance. Gene expression profiling by RNA sequencing showed that the increased activity of glycolytic enzymes was consistent with changes in gene expression. However, the decreased ATP production capacity of mitochondria was not in line with the gene expression. The potential direct interaction between cancer cells and skeletal muscle cells revealed in this study may contribute to a better fundamental understanding of the complex pathophysiology of cancer cachexia.NEW & NOTEWORTHY We explored the potential direct interplay between colon cancer cells (Colon-26) and skeletal muscle cells (C2C12 myotubes) employing a noncontact coculture experimental model. Our findings reveal that coculturing with Colon-26 cells substantially impairs the protein synthesis rate, concurrently instigating a metabolic shift toward glycolytic dominance in C2C12 myotubes. This research unveils critical insights into the intricate cellular cross talk underpinning the complex pathophysiology of cancer cachexia.

Futile lipid cycling: from biochemistry to physiology

In the healthy state, the fat stored in our body isn't just inert. Rather, it is dynamically mobilized to maintain an adequate concentration of fatty acids (FAs) in our bloodstream. Our body tends to produce excess FAs to ensure that the FA availability is not limiting. The surplus FAs are actively re-esterified into glycerides, initiating a cycle of breakdown and resynthesis of glycerides. This cycle consumes energy without generating a new product and is commonly referred to as the 'futile lipid cycle' or the glyceride/FA cycle. Contrary to the notion that it's a wasteful process, it turns out this cycle is crucial for systemic metabolic homeostasis. It acts as a control point in intra-adipocyte and inter-organ cross-talk, a metabolic rheostat, an energy sensor and a lipid diversifying mechanism. In this Review, we discuss the metabolic regulation and physiological implications of the glyceride/FA cycle and its mechanistic underpinnings.

Exosomes in the pathogenesis and treatment of cancer-related cachexia

Cancer-related cachexia is a metabolic syndrome characterized by weight loss, adipose tissue decomposition, and progressive skeletal muscle atrophy. It is a major complication of many advanced cancers and seriously affects the quality of life and survival of cancer patients. However, the specific molecules that mediate cancer-related cachexia remain elusive, and the fundamental cellular and molecular mechanisms associated with muscle atrophy and lipidolysis in cancer patients still need to be investigated. Exosomes, a newly discovered class of small extracellular vesicles that facilitate intercellular communication, have a significant role in the onset and development of various cancers. Studies have shown that exosomes play a role in the onset and progression of cancer-related cachexia by transporting active molecules such as nucleic acids and proteins. This review aimed to provide an overview of exosome developments in cancer-induced skeletal muscle atrophy and adipose tissue degradation. More importantly, exosomes were shown to have potential as diagnostic markers or therapeutic strategies for cachexia and were prospected, providing novel strategies for the diagnosis and treatment of cancer-related cachexia.

Astaxanthin Ameliorates Skeletal Muscle Atrophy in Mice With Cancer Cachexia

Astaxanthin (AST) is a natural marine carotenoid with a variety of biological activities. This study aimed to demonstrate the possible mechanisms by which AST improves skeletal muscle atrophy in cancer cachexia. In this study, the effects of different doses of AST (30 mg/kg b.w., 60 mg/kg b.w. and 120 mg/kg b.w.) on skeletal muscle functions were explored in mice with cancer cachexia. The results showed that AST (30, 60 and 120 mg/kg b.w.) could effectively protect cachexia mice from body weight and skeletal muscle loss. AST dose-dependently ameliorated the decrease in myofibres cross-sectional area and increased the expression of myosin heavy chain (MHC). AST treatment decreased both the serum and muscle level of IL-6 but not TNF-α in C26 tumor-bearing cachexia mice. Moreover, AST alleviated skeletal muscle atrophy by decreasing the expression of two muscle-specific E3 ligases MAFBx and MuRF-1. AST improved mitochondrial function by downregulating the levels of muscle Fis1, LC3B and Bax, upregulating the levels of muscle Mfn2 and Bcl-2. In conclusion, our study show that AST might be expected to be a nutritional supplement for cancer cachexia patients.

[Cancer-associated cachexia: an unresolved disease]

Cachexia is a systemic wasting condition associated to advanced phases of many cancers, which contributes to significant morbidity and mortality. It is mainly characterized by involuntary weight loss due to muscle wasting often associated with loss of adipose tissue, possibly leading to inanition and death, without treatment to date. Symptomatology covers a complex array of disorders (fatigue, inflammation, pain, anorexia, depression) related to multisystemic impairments progressively affecting numerous organs and tissues (muscle, adipose tissue, brain, immune system, gastrointestinal tract). The mechanisms of induction and progression of the disease, still poorly understood, involve inflammatory, metabolic, and neuroendocrine drivers, triggered by a variety of mediators originating from tumor, tumor-host interactions, and inter-organ crosstalk.

Cancer cachexia: biomarkers and the influence of age

Cancer cachexia (Ccx) is a complex metabolic condition characterized by pronounced muscle and fat wasting, systemic inflammation, weakness and fatigue. Up to 30% of cancer patients succumb directly to Ccx, yet therapies that effectively address this perturbed metabolic state are rare. In recent decades, several characteristics of Ccx have been established in mice and humans, of which we here highlight adipose tissue dysfunction, muscle wasting and systemic inflammation, as they are directly linked to biomarker discovery. To counteract cachexia pathogenesis as early as possible and mitigate its detrimental impact on anti-cancer treatments, identification and validation of clinically endorsed biomarkers assume paramount importance. Ageing was recently shown to affect both the validity of Ccx biomarkers and Ccx development, but the underlying mechanisms are still unknown. Thus, unravelling the intricate interplay between ageing and Ccx can help to counteract Ccx pathogenesis and tailor diagnostic and treatment strategies to individual needs.

Nav1.8-expressing neurons control daily oscillations of food intake, body weight and gut microbiota in mice

Recent evidence suggests a role of sensory neurons expressing the sodium channel Nav1.8 on the energy homeostasis control. Using a murine diphtheria toxin ablation strategy and ad libitum and time-restricted feeding regimens of control or high-fat high-sugar diets, here we further explore the function of these neurons on food intake and on the regulation of gastrointestinal elements transmitting immune and nutrient sensing.The Nav1.8+ neuron ablation increases food intake in ad libitum and time-restricted feeding, and exacerbates daily body weight variations. Mice lacking Nav1.8+ neurons show impaired prandial regulation of gut hormone secretion and gut microbiota composition, and altered intestinal immunity.Our study demonstrates that Nav1.8+ neurons are required to control food intake and daily body weight changes, as well as to maintain physiological enteroendocrine and immune responses and the rhythmicity of the gut microbiota, which highlights the potential of Nav1.8+ neurons to restore energy balance in metabolic disorders.

Metabolomics analysis reveals novel serum metabolite alterations in cancer cachexia

Background

Cachexia is a body wasting syndrome that significantly affects well-being and prognosis of cancer patients, without effective treatment. Serum metabolites take part in pathophysiological processes of cancer cachexia, but apart from altered levels of select serum metabolites, little is known on the global changes of the overall serum metabolome, which represents a functional readout of the whole-body metabolic state. Here, we aimed to comprehensively characterize serum metabolite alterations and analyze associated pathways in cachectic cancer patients to gain new insights that could help instruct strategies for novel interventions of greater clinical benefit.

Methods

Serum was sampled from 120 metastatic cancer patients (stage UICC IV). Patients were grouped as cachectic or non-cachectic according to the criteria for cancer cachexia agreed upon international consensus (main criterium: weight loss adjusted to body mass index). Samples were pooled by cachexia phenotype and assayed using non-targeted gas chromatography-mass spectrometry (GC-MS). Normalized metabolite levels were compared using t-test (p < 0.05, adjusted for false discovery rate) and partial least squares discriminant analysis (PLS-DA). Machine-learning models were applied to identify metabolite signatures for separating cachexia states. Significant metabolites underwent MetaboAnalyst 5.0 pathway analysis.

Results

Comparative analyses included 78 cachectic and 42 non-cachectic patients. Cachectic patients exhibited 19 annotable, significantly elevated (including glucose and fructose) or decreased (mostly amino acids) metabolites associating with aminoacyl-tRNA, glutathione and amino acid metabolism pathways. PLS-DA showed distinct clusters (accuracy: 85.6%), and machine-learning models identified metabolic signatures for separating cachectic states (accuracy: 83.2%; area under ROC: 88.0%). We newly identified altered blood levels of erythronic acid and glucuronic acid in human cancer cachexia, potentially linked to pentose-phosphate and detoxification pathways.

Conclusion

We found both known and yet unknown serum metabolite and metabolic pathway alterations in cachectic cancer patients that collectively support a whole-body metabolic state with impaired detoxification capability, altered glucose and fructose metabolism, and substrate supply for increased and/or distinct metabolic needs of cachexia-associated tumors. These findings together imply vulnerabilities, dependencies and targets for novel interventions that have potential to make a significant impact on future research in an important field of cancer patient care.

Association between skeletal muscle and left ventricular mass in patients with hyperthyroidism

Objective

This study aims to investigate the relationship between skeletal muscle and left ventricular mass (LVM) in patients with hyperthyroidism, providing theoretical and data-based foundations for further research on the interaction between secondary muscle atrophy and cardiac remodeling.

Methods

A retrospective data collection was conducted, including 136 patients with hyperthyroidism (Study group) and 50 healthy participants (control group). The Study group was further divided into Group A (high LVM) and Group B (low LVM) based on LVM size. Multiple linear regression analysis was performed to examine the correlation between skeletal muscle and LVM, with model evaluation. Based on the results, further nonlinear regression analysis was conducted to explore the detailed relationship between skeletal muscle and LVM.

Results

Compared to the control group, the Study group exhibited significantly lower LVM, skeletal muscle mass index (SMI), and skeletal muscle mass (SMM) (P<0.05). Within the subgroups, Group A had significantly higher SMI, SMM, and hand grip strength compared to Group B (P<0.05). The results of the multiple linear regression showed a certain correlation between SMI (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM. However, the residuals of the multiple regression did not follow a normal distribution (K-S=2.50, P<0.01). Further results from a generalized linear model and structural equation modeling regression also demonstrated a correlation between SMI (β=0.60, P=0.040, 95% CI=0.03~1.17) (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.043, 95% CI=0.01~0.67) (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM.

Conclusion

Patients with hyperthyroidism may exhibit simultaneous decreases in LVM, SMM, and SMI. The LVM in patients is correlated with SMM and hand grip strength, highlighting the need for further exploration of the causal relationship and underlying mechanisms. These findings provide a basis for the prevention and treatment of secondary sarcopenia and cardiac pathology in patients with hyperthyroidism.

Leukemia inhibitory factor suppresses hepatic de novo lipogenesis and induces cachexia in mice

Cancer cachexia is a systemic metabolic syndrome characterized by involuntary weight loss, and muscle and adipose tissue wasting. Mechanisms underlying cachexia remain poorly understood. Leukemia inhibitory factor (LIF), a multi-functional cytokine, has been suggested as a cachexia-inducing factor. In a transgenic mouse model with conditional LIF expression, systemic elevation of LIF induces cachexia. LIF overexpression decreases de novo lipogenesis and disrupts lipid homeostasis in the liver. Liver-specific LIF receptor knockout attenuates LIF-induced cachexia, suggesting that LIF-induced functional changes in the liver contribute to cachexia. Mechanistically, LIF overexpression activates STAT3 to downregulate PPARα, a master regulator of lipid metabolism, leading to the downregulation of a group of PPARα target genes involved in lipogenesis and decreased lipogenesis in the liver. Activating PPARα by fenofibrate, a PPARα agonist, restores lipid homeostasis in the liver and inhibits LIF-induced cachexia. These results provide valuable insights into cachexia, which may help develop strategies to treat cancer cachexia.

β‑carotene attenuates muscle wasting in cancer cachexia by regulating myogenesis and muscle atrophy

Cancer cachexia is a metabolic disease involving multiple organs, which is accompanied by the depletion of muscle tissue and is associated with ~20% of cancer‑related deaths. Muscle wasting is a critical factor in cancer cachexia. β‑carotene (BC) has been shown to increase muscle mass and hypertrophy in healthy mice. However, its effects on muscle tissue dysregulation in cancer cachexia have yet to be studied. In the present study, 5‑week‑old male C57BL/6J mice were injected with 1x106 Lewis lung carcinoma (LLC) cells to induce cancer cachexia; then the mice were administered BC (4 or 8 mg/kg) for 22 days to assess its effects on muscle atrophy in the gastrocnemius muscles. The effects of BC on inflammatory cytokines, myogenesis and muscle atrophy were evaluated using C2C12 myotubes treated with LLC‑conditioned media. BC supplementation significantly suppressed tumor growth, inflammatory cytokines, and hepatic gluconeogenesis in the LLC‑induced cancer cachexia mouse model, while also improving muscle weight and grip strength. These effects are considered to be mediated by the PI3K/Akt pathway and through regulation of muscle atrophy. Moreover, BC treatment was associated with the recovery of LLC‑conditioned media‑induced muscle differentiation deficits and muscle atrophy in C2C12 myotubes. These findings indicate BC as a potential novel therapeutic agent for cancer cachexia.

Metabolic signatures and potential biomarkers for the diagnosis and treatment of colon cancer cachexia

Cancer cachexia (CAC) is a debilitating condition that often arises from noncachexia cancer (NCAC), with distinct metabolic characteristics and medical treatments. However, the metabolic changes and underlying molecular mechanisms during cachexia progression remain poorly understood. Understanding the progression of CAC is crucial for developing diagnostic approaches to distinguish between CAC and NCAC stages, facilitating appropriate treatment for cancer patients. In this study, we establish a mouse model of colon CAC and categorize the mice into three groups: CAC, NCAC and normal control (NOR). By performing nuclear magnetic resonance (NMR)-based metabolomic profiling on mouse sera, we elucidate the metabolic properties of these groups. Our findings unveil significant differences in the metabolic profiles among the CAC, NCAC and NOR groups, highlighting significant impairments in energy metabolism and amino acid metabolism during cachexia progression. Additionally, we observe the elevated serum levels of lysine and acetate during the transition from the NCAC to CAC stages. Using multivariate ROC analysis, we identify lysine and acetate as potential biomarkers for distinguishing between CAC and NCAC stages. These biomarkers hold promise for the diagnosis of CAC from noncachexia cancer. Our study provides novel insights into the metabolic mechanisms underlying cachexia progression and offers valuable avenues for the diagnosis and treatment of CAC in clinical settings.

Insulin in combination with pioglitazone prevents advanced cachexia in 256-Walker tumor-bearing rats: effect is greater than treatment alone and is associated with improved insulin sensitivity

BACKGROUND

Insulin (INS) resistance and hypoinsulinemia commonly observed in cancer-carrying, can contribute to cachexia. However, the effects of INS and INS sensitizers, such as pioglitazone (PIO), particularly when used in combination therapy, on cancer cachexia have not been evaluated sufficiently. We investigated the effects of INS and PIO, at various doses, either isolated or combined, on cachexia in Walker-256 tumor-bearing rats (TB rats).

METHODS

INS or INS + PIO were administered in TB rats, for 6 or 12 days, starting from the day of tumor cells inoculation.

RESULTS

INS at 18 or 27 U/kg (12-days treatment), but not 9 U/kg, reduced fat loss and slightly prevented weight loss. However, INS 18 U/kg + PIO 5, 10, 20, or 40 mg/kg (6 or 12-day treatment) reduced fat loss and markedly prevented weight loss but did not affect muscle wasting. While TB rats lost weight (37.9% in 12 days), TB rats treated with INS 18 U/kg + PIO 5 mg/kg showed pronounced weight gain (73.7%), which was greater than the sum (synergism) of the weight gains promoted by isolated treatments with INS 18 U/kg (14.7%) or PIO 5 mg/kg (13.1%). The beneficial effect of the INS 18 U/kg + PIO 5 mg/kg on weight loss was associated with improved INS sensitivity, as indicated by the higher blood glucose clearance constant (kITT), decreased levels of free fatty acids and triacylglycerols (INS resistance-inducing factors) in the blood, and increased expression of p-Akt (INS signaling pathway protein) in adipose tissue.

CONCLUSIONS

The combined treatment with INS 18 U/kg + PIO 5 mg/kg was more effective in preventing advanced cachexia in TB rats than each treatment alone, emerging as the best approach, considering the lower dosage and higher efficacy. This combination completely preserved adipose mass and markedly reduced weight loss through a synergistic mechanism linked to improved insulin sensitivity. These findings provide new insights into the importance of drug combinations in effectively combating fat loss in advanced cachexia.

Decreased liver B vitamin-related enzymes as a metabolic hallmark of cancer cachexia

Cancer cachexia is a complex metabolic disorder accounting for ~20% of cancer-related deaths, yet its metabolic landscape remains unexplored. Here, we report a decrease in B vitamin-related liver enzymes as a hallmark of systemic metabolic changes occurring in cancer cachexia. Metabolomics of multiple mouse models highlights cachexia-associated reductions of niacin, vitamin B6, and a glycine-related subset of one-carbon (C1) metabolites in the liver. Integration of proteomics and metabolomics reveals that liver enzymes related to niacin, vitamin B6, and glycine-related C1 enzymes dependent on B vitamins decrease linearly with their associated metabolites, likely reflecting stoichiometric cofactor-enzyme interactions. The decrease of B vitamin-related enzymes is also found to depend on protein abundance and cofactor subtype. These metabolic/proteomic changes and decreased protein malonylation, another cachexia feature identified by protein post-translational modification analysis, are reflected in blood samples from mouse models and gastric cancer patients with cachexia, underscoring the clinical relevance of our findings.

Gut microbiota in muscular atrophy development, progression, and treatment: New therapeutic targets and opportunities

Skeletal muscle atrophy is a debilitating condition that significantly affects quality of life and often lacks effective treatment options. Muscle atrophy can have various causes, including myogenic, neurogenic, and other factors. Recent investigation has underscored a compelling link between the gut microbiota and skeletal muscle. Discerning the potential differences in the gut microbiota associated with muscle atrophy-related diseases, understanding their influence on disease development, and recognizing their potential as intervention targets are of paramount importance. This review aims to provide a comprehensive overview of the role of the gut microbiota in muscle atrophy-related diseases. We summarize clinical and pre-clinical studies that investigate the potential for gut microbiota modulation to enhance muscle performance and promote disease recovery. Furthermore, we delve into the intricate interplay between the gut microbiota and muscle atrophy-related diseases, drawing from an array of studies. Emerging evidence suggests significant differences in gut microbiota composition in individuals with muscle atrophy-related diseases compared with healthy individuals. It is conceivable that these alterations in the microbiota contribute to the pathogenesis of these disorders through bacterium-related metabolites or inflammatory signals. Additionally, interventions targeting the gut microbiota have demonstrated promising results for mitigating disease progression in animal models, underscoring the therapeutic potential of modulating the gut microbiota in these conditions. By analyzing the available literature, this review sheds light on the involvement of the gut microbiota in muscle atrophy-related diseases. The findings contribute to our understanding of the underlying mechanisms and open avenues for development of novel therapeutic strategies targeting the gut-muscle axis.

Females display relatively preserved muscle quality compared with males during the onset and early stages of C26-induced cancer cachexia

Cancer cachexia is clinically defined by involuntary weight loss >5% in <6 mo, primarily affecting skeletal muscle. Here, we aimed to identify sex differences in the onset of colorectal cancer cachexia with specific consideration to skeletal muscle contractile and metabolic functions. Eight-weeks old BALB/c mice (69 males, 59 females) received subcutaneous C26 allografts or PBS vehicle. Tumors were developed for 10-, 15-, 20-, or 25 days. Muscles and organs were collected, in vivo muscle contractility, protein synthesis rate, mitochondrial function, and protein turnover markers were assessed. One-way ANOVA within sex and trend analysis between sexes were performed, P < 0.05. Gastrocnemius and tibialis anterior (TA) muscles became atrophic in male mice at 25 days, whereas female mice exhibited no significant differences in muscle weights at endpoints despite presenting hallmarks of cancer cachexia (fat loss, hepatosplenomegaly). We observed lowered muscle contractility and protein synthesis concomitantly to muscle mass decay in males, with higher proteolytic markers in muscles of both sexes. mRNA of Opa1 was lower in TA, whereas Bnip3 was higher in gastrocnemius after 25 days in male mice, with no significant effect in female mice. Our data suggest relative protections to skeletal muscle in females compared with males despite other canonical signs of cancer cachexia and increased protein degradation markers; suggesting we should place onus upon nonmuscle tissues during early stages of cancer cachexia in females. We noted potential protective mechanisms relating to skeletal muscle contractile and mitochondrial functions. Our findings underline possible heterogeneity in onset of cancer cachexia between biological sexes, suggesting the need for sex-specific approaches to treat cancer cachexia.NEW & NOTEWORTHY Our study demonstrates biological-sex differences in phenotypic characteristics of cancer cachexia between male and female mice, whereby females display many common characteristics of cachexia (gonadal fat loss and hepatosplenomegaly), protein synthesis markers alterations, and common catabolic markers in skeletal muscle despite relatively preserved muscle mass in early-stage cachexia compared with males. Mechanisms of cancer cachexia appear to differ between sexes. Data suggest need to place onus of early cancer cachexia detection and treatment on nonmuscle tissues in females.

Astaxanthin Supplementation Assists Sorafenib in Slowing Skeletal Muscle Atrophy in H22 Tumor-Bearing Mice via Reversing Abnormal Glucose Metabolism

SCOPE

Cachexia, which is often marked by skeletal muscular atrophy, is one of the leading causes of death in cancer patients. Astaxanthin, a carotenoid obtained from marine organisms that can aid in the prevention and treatment of a variety of disorders. In this study, to assess whether astaxanthin ameliorates weight loss and skeletal muscle atrophy in sorafenib-treated hepatocellular carcinoma mice is aimed.

METHODS AND RESULTS

H22 mice are treated with 30 mg kg-1  day-1 of sorafenib and 60 mg kg-1  day-1 of astaxanthin by gavage lasted for 18 days. Sorafenib does not delay skeletal muscle atrophy and weight loss, although it does not reduce tumor burden. Astaxanthin dramatically delays weight loss and skeletal muscle atrophy in sorafenib-treating mice, without affecting the food intake. Astaxanthin inhibits the tumor glycolysis, slows down gluconeogenesis, and improves insulin resistance in tumor-bearing mice. Astaxanthin increases glucose competition in skeletal muscle by targeting the PI3K/Akt/GLUT4 signaling pathway, and enhances glucose utilization efficiency in skeletal muscle, thereby slowing skeletal muscle atrophy.

CONCLUSION

The findings show the significant potential of astaxanthin as nutritional supplements for cancer patients, as well as the notion that nutritional interventions should be implemented at the initiation of cancer treatment, as instead of waiting until cachexia sets in.

Tricarboxylic acid (TCA) cycle, sphingolipid, and phosphatidylcholine metabolism are dysregulated in T. gondii infection-induced cachexia

Cachexia is a life-threatening disease characterized by chronic, inflammatory muscle wasting and systemic metabolic impairment. Despite its high prevalence, there are no efficacious therapies for cachexia. Mice chronically infected with the protozoan parasite Toxoplasma gondii represent a novel animal model recapitulating the chronic kinetics of cachexia. To understand how perturbations to metabolic tissue homeostasis influence circulating metabolite availability we used mass spectrometry analysis. Despite the significant reduction in circulating triacylglycerides, non-esterified fatty acids, and glycerol, sphingolipid long-chain bases and a subset of phosphatidylcholines (PCs) were significantly increased in the sera of mice with T. gondii infection-induced cachexia. In addition, the TCA cycle intermediates α-ketoglutarate, 2-hydroxyglutarate, succinate, fumarate, and malate were highly depleted in cachectic mouse sera. Sphingolipids and their de novo synthesis precursors PCs are the major components of the mitochondrial membrane and regulate mitochondrial function consistent with a causal relationship in the energy imbalance driving T. gondii-induced chronic cachexia.

EXT418, a novel long-acting ghrelin, mitigates Lewis lung carcinoma induced cachexia in mice

BACKGROUND

Ghrelin is a potential therapy for cachexia due to its orexigenic properties and anabolic effects on muscle and fat. However, its clinical use is limited by the short half-life of active (acylated) ghrelin (~11 min in humans). EXT418 is a novel long-acting, constitutively active ghrelin analog created by covalently linking it to a vitamin D derivative. Here, we evaluated the effects and mechanisms of action of EXT418 on Lewis lung carcinoma (LLC)-induced cachexia in mice.

METHODS

Male C57BL/6J mice (5- to 7-month-old) were implanted with 1 × 106 heat-killed (HK) or live LLC cells. When the tumour was palpable, mice were injected with vehicle (T + V) or EXT418 daily (T + 418 Daily, 0.25 mg/kg/day) or every other day (T + 418 EOD, 0.5 mg/kg/EOD) for up to 14 days, whereas HK-treated mice were given vehicle (HK + V). Subsets of T + 418 Daily or EOD-treated mice were pair-fed to the T + V group. Body composition and grip strength were evaluated before tumour implantation and at the end of the experiment. Molecular markers were probed in muscles upon termination.

RESULTS

In tumour-bearing mice, administration of EXT418 daily or EOD partially prevented weight loss (T + V vs. T + 418 Daily, P = 0.030; and vs. T + 418 EOD, P = 0.020). Similar effects were observed in whole body fat and lean body mass. Grip strength in tumour-bearing mice was improved by EXT418 daily (P = 0.010) or EOD (P = 0.008) administration compared with vehicle-treated mice. These effects of EXT418 on weight and grip strength were partially independent of food intake. EXT418 daily administration also improved type IIA (P = 0.015), IIB (P = 0.037) and IIX (P = 0.050) fibre cross-sectional area (CSA) in tibialis anterior (TA) and EXT418 EOD improved CSA of IIB fibres in red gastrocnemius (GAS; P = 0.005). In skeletal muscles, tumour-induced increases in atrogenes Fbxo32 and Trim63 were ameliorated by EXT418 treatments (TA and GAS/plantaris, PL), which were independent of food intake. EXT418 administration decreased expression of the mitophagy marker Bnip3 (GAS/PL; P ≤ 0.010). Similar effects of EXT418 EOD were observed in p62 (GAS/PL; P = 0.039). In addition, EXT418 treatments ameliorated the tumour-induced elevation in muscle Il6 transcript levels (TA and GAS/PL), independently of food intake. Il-6 transcript levels in adipose tissue and circulating IL-10 were elevated in response to the tumour but these increases were not significant with EXT418 administration. Tumour mass was not altered by EXT418.

CONCLUSIONS

EXT418 mitigates LLC-induced cachexia by attenuating skeletal muscle inflammation, proteolysis, and mitophagy, without affecting tumour mass and partially independent of food intake.

Cytarabine induces cachexia with lipid malabsorption via zippering the junctions of lacteal in murine small intestine

Chemotherapy-induced cachexia causes severe metabolic abnormalities independently of cancer and reduces the therapeutic efficacy of chemotherapy. The underlying mechanism of chemotherapy-induced cachexia remains unclear. Here we investigated the cytarabine (CYT)-induced alteration in energy balance and its underlying mechanisms in mice. We compared energy balance-associated parameters among the three groups of mice: CON, CYT, and PF (pair-fed mice with the CYT group) that were intravenously administered vehicle or CYT. Weight gain, fat mass, skeletal muscle mass, grip strength, and nocturnal energy expenditure were significantly lowered in the CYT group than in the CON and PF groups. The CYT group demonstrated less energy intake than the CON group and higher respiratory quotient than the PF group, indicating that CYT induced cachexia independently from the anorexia-induced weight loss. Serum triglyceride was significantly lower in the CYT group than in the CON group, whereas the intestinal mucosal triglyceride levels and the lipid content within the small intestine enterocyte were higher after lipid loading in the CYT group than in the CON and PF groups, suggesting that CYT inhibited lipid uptake in the intestine. This was not associated with obvious intestinal damage. The CYT group showed increased zipper-like junctions of lymphatic endothelial vessel in duodenal villi compared to that in the CON and CYT groups, suggesting their imperative role in the CYT-induced inhibition of lipid uptake. CYT worsens cachexia independently of anorexia by inhibiting the intestinal lipid uptake, via the increased zipper-like junctions of lymphatic endothelial vessel.

The effect of different boron compounds on nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism

BACKGROUND

Gastrointestinal health is essential for maintaining a healthy lifestyle. Improving nutrient absorption and energy metabolism are the critical targets for intestinal health. This study aimed to determine the effects of different boron (B) derivatives on nutrient digestibility, intestinal nutrient transporters, and lipid metabolism in rats.

METHODS

Twenty-one rats were allocated to three groups (n = 7) as follows: (i) Control, (ii) Sodium pentaborate pentahydrate (SPP), and (iii) boric acid (BA). The rats were fed a chow diet (AIN-93M) and supplemented with 8 mg/kg elemental B from SPP (45.2 mg/kg BW) and BA (42.7 mg/kg BW) via oral gavage every other day for 12 weeks. The nutrient digestibility of rats in each group was measured using the indigestible indicator (chromium oxide, Cr2 O3, 0.20%). At the end of the experiment, animals were decapitated by cervical dislocation and jejunum, and liver samples were taken from each animal. The nutrient transporters and lipid-regulated transcription factors were determined by RT-PCR.

RESULTS

The nutrient digestibility (except for ash) was increased by SPP and BA supplementation (p < 0.05). SPP and BA-supplemented rats had higher jejunal glucose transporter 1 (GLUT1), GLUT2, GLUT5, sodium-dependent glucose transporter 1 (SGLT1), fatty acid transport protein-1 (FATP1), and FATP4 mRNA expression levels compared to nonsupplemented rats (p < 0.0001). BA-supplemented rats had remarkably higher peroxisome proliferator-activated receptor gamma (PPARγ) levels than nonsupplemented rats (p < 0.0001). In contrast, sterol regulatory element-binding protein 1c (SREBP-1c), liver X receptor alpha (LxR-α), and fatty acid synthase (FAS) levels decreased by SPP supplementation compared to other groups (p < 0.05).

DISCUSSION

SPP and BA administration enhanced nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism in rats.

The Role of Natural Products in the Improvement of Cancer-Associated Cachexia

The enormous library of natural products and herbal medicine prescriptions presents endless research avenues. However, the lack of research evidence and trials on cancer-induced cachexia limit the therapeutic potential of natural products. Cancer-induced cachexia is a systemic wasting syndrome characterized by continuous body weight loss with skeletal muscle and adipose tissue atrophy. Cancer cachexia is a problem in itself and reduces the quality of life by lessening the treatment efficacy of anticancer drugs. This review summarizes single natural product extracts for cancer-induced cachexia, not compounds derived from natural products and herbal medicine prescriptions. This article also discusses the effect of natural products on cachexia induced by anticancer drugs and the role of AMPK in cancer-induced cachexia. The article included the mice model used in each experiment to encourage researchers to utilize animal models for research on cancer-induced cachexia in the future.

Cachexia causes time-dependent activation of the inflammasome in the liver

BACKGROUND

Cachexia is a wasting syndrome associated with systemic inflammation and metabolic disruption. Detection of the early signs of the disease may contribute to the effective attenuation of associated symptoms. Despite playing a central role in the control of metabolism and inflammation, the liver has received little attention in cachexia. We previously described relevant disruption of metabolic pathways in the organ in an animal model of cachexia, and herein, we adopt the same model to investigate temporal onset of inflammation in the liver. The aim was thus to study inflammation in rodent liver in the well-characterized cachexia model of Walker 256 carcinosarcoma and, in addition, to describe inflammatory alterations in the liver of one cachectic colon cancer patient, as compared to one control and one weight-stable cancer patient.

METHODS

Colon cancer patients (one weight stable [WSC] and one cachectic [CC]) and one patient undergoing surgery for cholelithiasis (control, n = 1) were enrolled in the study, after obtainment of fully informed consent. Eight-week-old male rats were subcutaneously inoculated with a Walker 256 carcinosarcoma cell suspension (2 × 10⁷ cells in 1.0 mL; tumour-bearing [T]; or phosphate-buffered saline-controls [C]). The liver was excised on Days 0 (n = 5), 7 (n = 5) and 14 (n = 5) after tumour cell injection.

RESULTS

In rodent cachexia, we found progressively higher numbers of CD68⁺ myeloid cells in the liver along cancer-cachexia development. Similar findings are described for CC, whose liver showed infiltration of the same cell type, compared with both WSC and control patient organs. In advanced rodent cachexia, hepatic phosphorylated c-Jun N-terminal kinase protein content and the inflammasome pathway protein expression were increased in relation to baseline (P < 0.05). These changes were accompanied by augmented expression of the active interleukin-1β (IL-1β) form (P < 0.05 for both circulating and hepatic content).

CONCLUSIONS

The results show that cancer cachexia is associated with an increase in the number of myeloid cells in rodent and human liver and with modulation of hepatic inflammasome pathway. The latter contributes to the aggravation of systemic inflammation, through increased release of IL-1β.

Cancer cachexia as a blueprint for treating obesity

Effective pharmacological treatments to achieve significant and sustained weight loss in obese individuals remain limited. Here, we apply a 'reverse engineering' approach to cancer cachexia, an extreme form of dysregulated energy balance resulting in net catabolism. We discuss three phenotypic features of the disease, summarize the underlying molecular checkpoints, and explore their translation to obesity research. We then provide examples for established pharmaceuticals, which follow a reverse engineering logic, and propose additional targets that may be of relevance for future studies. Finally, we argue that approaching diseases from this perspective may prove useful as a generic strategy to fuel the development of innovative therapies.

Understanding the relationship between cancer associated cachexia and hypoxia-inducible factor-1

Cancer-associated cachexia (CAC) is a multifactorial disorder characterized by an unrestricted loss of body weight as a result of muscle and adipose tissue atrophy. Cachexia is influenced by several factors, including decreased metabolic activity and food intake, an imbalance between energy uptake and expenditure, excessive catabolism, and inflammation. Cachexia is highly associated with all types of cancers responsible for more than half of cancer-related mortalities worldwide. In healthy individuals, adipose tissue significantly regulates energy balance and glucose homeostasis. However, in metastatic cancer patients, CAC occurs mainly because of an imbalance between muscle protein synthesis and degradation which are organized by certain extracellular ligands and associated signaling pathways. Under hypoxic conditions, hypoxia-inducible factor-1 (HIF-1α) accumulated and translocated to the nucleus and activate numerous genes involved in cell survival, invasion, angiogenesis, metastasis, metabolic reprogramming, and cancer stemness. On the other hand, the ubiquitination proteasome pathway is inhibited during low O2 levels which promote muscle wasting in cancer patients. Therefore, understanding the mechanism of the HIF-1 pathway and its metabolic adaptation to biomolecules is important for developing a novel therapeutic method for cancer and cachexia therapy. Even though many HIF inhibitors are already in a clinical trial, their mechanism of action remains unknown. With this background, this review summarizes the basic concepts of cachexia, the role of inflammatory cytokines, pathways connected with cachexia with special reference to the HIF-1 pathway and its regulation, metabolic changes, and inhibitors of HIFs.

IGFBP-3 promotes cachexia-associated lipid loss by suppressing insulin-like growth factor/insulin signaling

BACKGROUND

Progressive lipid loss of adipose tissue is a major feature of cancer-associated cachexia. In addition to systemic immune/inflammatory effects in response to tumor progression, tumor-secreted cachectic ligands also play essential roles in tumor-induced lipid loss. However, the mechanisms of tumor-adipose tissue interaction in lipid homeostasis are not fully understood.

METHODS

The yki -gut tumors were induced in fruit flies. Lipid metabolic assays were performed to investigate the lipolysis level of different types of insulin-like growth factor binding protein-3 (IGFBP-3) treated cells. Immunoblotting was used to display phenotypes of tumor cells and adipocytes. Quantitative polymerase chain reaction (qPCR) analysis was carried out to examine the gene expression levels such as Acc1 , Acly , and Fasn et al .

RESULTS

In this study, it was revealed that tumor-derived IGFBP-3 was an important ligand directly causing lipid loss in matured adipocytes. IGFBP-3, which is highly expressed in cachectic tumor cells, antagonized insulin/IGF-like signaling (IIS) and impaired the balance between lipolysis and lipogenesis in 3T3-L1 adipocytes. Conditioned medium from cachectic tumor cells, such as Capan-1 and C26 cells, contained excessive IGFBP-3 that potently induced lipolysis in adipocytes. Notably, neutralization of IGFBP-3 by neutralizing antibody in the conditioned medium of cachectic tumor cells significantly alleviated the lipolytic effect and restored lipid storage in adipocytes. Furthermore, cachectic tumor cells were resistant to IGFBP-3 inhibition of IIS, ensuring their escape from IGFBP-3-associated growth suppression. Finally, cachectic tumor-derived ImpL2, the IGFBP-3 homolog, also impaired lipid homeostasis of host cells in an established cancer-cachexia model in Drosophila . Most importantly, IGFBP-3 was highly expressed in cancer tissues in pancreatic and colorectal cancer patients, especially higher in the sera of cachectic cancer patients than non-cachexia cancer patients.

CONCLUSION

Our study demonstrates that tumor-derived IGFBP-3 plays a critical role in cachexia-associated lipid loss and could be a biomarker for diagnosis of cachexia in cancer patients.

NAD+ repletion with niacin counteracts cancer cachexia

Cachexia is a debilitating wasting syndrome and highly prevalent comorbidity in cancer patients. It manifests especially with energy and mitochondrial metabolism aberrations that promote tissue wasting. We recently identified nicotinamide adenine dinucleotide (NAD⁺) loss to associate with muscle mitochondrial dysfunction in cancer hosts. In this study we confirm that depletion of NAD⁺ and downregulation of Nrk2, an NAD⁺ biosynthetic enzyme, are common features of severe cachexia in different mouse models. Testing NAD⁺ repletion therapy in cachectic mice reveals that NAD⁺ precursor, vitamin B3 niacin, efficiently corrects tissue NAD⁺ levels, improves mitochondrial metabolism and ameliorates cancer- and chemotherapy-induced cachexia. In a clinical setting, we show that muscle NRK2 is downregulated in cancer patients. The low expression of NRK2 correlates with metabolic abnormalities underscoring the significance of NAD⁺ in the pathophysiology of human cancer cachexia. Overall, our results propose NAD⁺ metabolism as a therapy target for cachectic cancer patients.

Cancer cachexia: involvement of an expanding macroenvironment

Advanced cancers often present with the cachexia syndrome that impacts peripheral tissues, leading to involuntary weight loss and reduced prognosis. The central tissues undergoing depletion are skeletal muscle and adipose, but recent findings reveal an expanding tumor macroenvironment involving organ crosstalks that underlie the cachectic state.

Brown adipose tissue is not associated with cachexia or increased mortality in a retrospective study of patients with cancer

Although brown fat is strongly associated with a constellation of cardiometabolic benefits in animal models and humans, it has also been tied to cancer cachexia. In humans, cancer-associated cachexia increases mortality, raising the possibility that brown fat in this context may be associated with increased cancer death. However, the effect of brown fat on cancer-associated cachexia and survival in humans remains unclear. Here, we retrospectively identify patients with and without brown fat on fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET) scans obtained as part of routine cancer care and assemble a cohort to address these questions. We did not find an association between brown fat status and cachexia. Furthermore, we did not observe an association between brown fat and increased mortality in patients with cachexia. Our analyses controlled for confounding factors including age at cancer diagnosis, sex, body mass index, cancer site, cancer stage, outdoor temperature, comorbid conditions (heart failure, type 2 diabetes mellitus, coronary artery disease, hypertension, dyslipidemia, cerebrovascular disease), and β-blocker use. Taken together, our results suggest that brown fat is not linked to cancer-associated cachexia and does not worsen overall survival in patients with cachexia.NEW & NOTEWORTHY This study finds that brown fat is not linked to cancer-associated cachexia. Moreover, this work shows that brown fat does not worsen overall survival in patients with cachexia.

Progressive development of melanoma-induced cachexia differentially impacts organ systems in mice

Cachexia is a systemic wasting syndrome that increases cancer-associated mortality. How cachexia progressively and differentially impacts distinct tissues is largely unknown. Here, we find that the heart and skeletal muscle undergo wasting at early stages and are the tissues transcriptionally most impacted by cachexia. We also identify general and organ-specific transcriptional changes that indicate functional derangement by cachexia even in tissues that do not undergo wasting, such as the brain. Secreted factors constitute a top category of cancer-regulated genes in host tissues, and these changes include upregulation of the angiotensin-converting enzyme (ACE). ACE inhibition with the drug lisinopril improves muscle force and partially impedes cachexia-induced transcriptional changes, although wasting is not prevented, suggesting that cancer-induced host-secreted factors can regulate tissue function during cachexia. Altogether, by defining prevalent and temporal and tissue-specific responses to cachexia, this resource highlights biomarkers and possible targets for general and tissue-tailored anti-cachexia therapies.

Impairment of adrenergically-regulated thermogenesis in brown fat of obesity-resistant mice is compensated by non-shivering thermogenesis in skeletal muscle

OBJECTIVE

Non-shivering thermogenesis (NST) mediated by uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) can be activated via the adrenergic system in response to cold or diet, contributing to both thermal and energy homeostasis. Other mechanisms, including metabolism of skeletal muscle, may also be involved in NST. However, relative contribution of these energy dissipating pathways and their adaptability remain a matter of long-standing controversy.

METHODS

We used warm-acclimated (30 °C) mice to characterize the effect of an up to 7-day cold acclimation (6 °C; CA) on thermoregulatory thermogenesis, comparing inbred mice with a genetic background conferring resistance (A/J) or susceptibility (C57BL/6 J) to obesity.

RESULTS

Both warm-acclimated C57BL/6 J and A/J mice exhibited similar cold endurance, assessed as a capability to maintain core body temperature during acute exposure to cold, which improved in response to CA, resulting in comparable cold endurance and similar induction of UCP1 protein in BAT of mice of both genotypes. Despite this, adrenergic NST in BAT was induced only in C57BL/6 J, not in A/J mice subjected to CA. Cold tolerance phenotype of A/J mice subjected to CA was not based on increased shivering, improved insulation, or changes in physical activity. On the contrary, lipidomic, proteomic and gene expression analyses along with palmitoyl carnitine oxidation and cytochrome c oxidase activity revealed induction of lipid oxidation exclusively in skeletal muscle of A/J mice subjected to CA. These changes appear to be related to skeletal muscle NST, mediated by sarcolipin-induced uncoupling of sarco(endo)plasmic reticulum calcium ATPase pump activity and accentuated by changes in mitochondrial respiratory chain supercomplexes assembly.

CONCLUSIONS

Our results suggest that NST in skeletal muscle could be adaptively augmented in the face of insufficient adrenergic NST in BAT, depending on the genetic background of the mice. It may provide both protection from cold and resistance to obesity, more effectively than BAT.

Targeting Gut Microbiota in Cancer Cachexia: Towards New Treatment Options

Cancer cachexia is a complex multifactorial syndrome whose hallmarks are weight loss due to the wasting of muscle tissue with or without the loss of adipose tissue, anorexia, systemic inflammation, and multi-organ metabolic alterations, which negatively impact patients' response to anticancer treatments, quality of life, and overall survival. Despite its clinical relevance, cancer cachexia often remains an underestimated complication due to the lack of rigorous diagnostic and therapeutic pathways. A number of studies have shown alterations in gut microbiota diversity and composition in association with cancer cachexia markers and symptoms, thus supporting a central role for dysbiosis in the pathogenesis of this syndrome. Different tools of microbiota manipulation, including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, have been investigated, demonstrating encouraging improvements in cachexia outcomes. Albeit pioneering, these studies pave the way for future research with the aim of exploring the role of gut microbiota in cancer cachexia more deeply and setting up effective microbiota-targeting interventions to be translated into clinical practice.

Caffeine-Supplemented Diet Prevents Fatigue-Like Behavior in Tumor-Bearing Mice

Caffeine is a widely consumed stimulant, known for its positive effects on physical and mental performance. These effects are potentially beneficial for ameliorating cancer-related fatigue, which affects the quality of life of patients with cancer. This study aimed to determine the anti-fatigue and antitumor effects of caffeine in tumor-bearing mice. BALB/c mice were intravenously injected with C26 colon carcinoma cells and fed with normal or 0.05% caffeine-supplemented diet. Fatigue-like behavior was assessed by running performance using a treadmill test. Lung, blood, liver, muscle, and epididymal adipose tissue samples were collected on day 13 and examined. The antitumor effect of caffeine was assessed using subcutaneous tumor-bearing mice fed with 0.05% caffeine-supplemented diet, and the tumor volume was measured. C26 tumor-bearing mice showed fatigue-like behavior associated with hypoglycemia, depleted liver glycogen and non-esterified fatty acid (NEFA) levels. C26 tumor-bearing mice fed with 0.05% caffeine-supplemented diet showed improved running performance associated with restored NEFA levels. However, exacerbated hypoglycemia and liver glycogen levels after caffeine consumption may be due to tumor-induced catabolic signals, as the tumor volume was not affected. Collectively, caffeine may exert anti-fatigue effects through enhanced lipolysis leading to restored NEFA levels, which can be used as an alternative energy source.

The Efficacy of Biological Disease-modifying Antirheumatic Drugs on Sarcopenia in Patients with Rheumatoid Arthritis

Objective Sarcopenia is characterized by a loss of muscle mass and strength, which leads to frailty and mortality. Rheumatoid arthritis (RA) is considered to be a cause of sarcopenia. The present study assessed the effectiveness of biological disease-modifying antirheumatic drugs (bDMARDs) on sarcopenia. Methods This was a prospective cohort study including 48 patients [11 men, 37 women; 67.5 (57.0-74.8) years old] with RA who started bDMARDs in Niigata Rheumatic Center. We monitored the physical ability, nutritional status and body composition at the baseline, 6 months and 12 months. The physical activity was measured by the Health Assessment Questionnaire (HAQ) and 10-m walking test (10MWT). The nutritional status was assessed by the controlling nutrition status (CONUT) score. Results Among the 48 patients who started bDMARDs, 21 were classified as having sarcopenia. The physical activity and nutritional status were significantly ameliorated after 12 months of bDMARDs. The body composition analysis showed a significant increase in the body weight but no significant increase in the skeletal muscle mass index. The proportion of patients diagnosed with sarcopenia decreased significantly after 12 months of bDMARDs (43.8% vs. 27.1%, p=0.039). Among the 21 patients who were diagnosed with sarcopenia when starting bDMARDs, the skeletal muscle index was significantly increased after 12 months of bDMARDs. [5.22 (4.76-5.43) kg/m² vs. 5.44 (4.84-5.77), p=0.039]. Conclusion Biologics may be useful in the treatment of sarcopenia through mechanisms such as improving the disease activity, physical activity and nutritional status.

Pathological features of tissues and cell populations during cancer cachexia

Cancers remain among the most devastating diseases in the human population in spite of considerable advances in limiting their impact on lifespan and healthspan. The multifactorial nature of cancers, as well as the number of tissues and organs that are affected, have exposed a considerable diversity in mechanistic features that are reflected in the wide array of therapeutic strategies that have been adopted. Cachexia is manifested in a number of diseases ranging from cancers to diabetes and ageing. In the context of cancers, a majority of patients experience cachexia and succumb to death due to the indirect effects of tumorigenesis that drain the energy reserves of different organs. Considerable information is available on the pathophysiological features of cancer cachexia, however limited knowledge has been acquired on the resident stem cell populations, and their function in the context of these diseases. Here we review current knowledge on cancer cachexia and focus on how tissues and their resident stem and progenitor cell populations are individually affected.

2-Deoxy-D-glucose Alleviates Cancer Cachexia-Induced Muscle Wasting by Enhancing Ketone Metabolism and Inhibiting the Cori Cycle

Cachexia is characterized by progressive weight loss accompanied by the loss of specific skeletal muscle and adipose tissue. Increased lactate production, either due to the Warburg effect from tumors or accelerated glycolysis effects from cachectic muscle, is the most dangerous factor for cancer cachexia. This study aimed to explore the efficiency of 2-deoxy-D-glucose (2-DG) in blocking Cori cycle activity and its therapeutic effect on cachexia-associated muscle wasting. A C26 adenocarcinoma xenograft model was used to study cancer cachectic metabolic derangements. Tumor-free lean mass, hindlimb muscle morphology, and fiber-type composition were measured after in vivo 2-DG administration. Activation of the ubiquitin-dependent proteasome pathway (UPS) and autophagic–lysosomal pathway (ALP) was further assessed. The cachectic skeletal muscles of tumor-bearing mice exhibited altered glucose and lipid metabolism, decreased carbohydrate utilization, and increased lipid β-oxidation. Significantly increased gluconeogenesis and decreased ketogenesis were observed in cachectic mouse livers. 2-DG significantly ameliorated cancer cachexia-associated muscle wasting and decreased cachectic-associated lean mass levels and fiber cross-sectional areas. 2-DG inhibited protein degradation-associated UPS and ALP, increased ketogenesis in the liver, and promoted ketone metabolism in skeletal muscle, thus enhancing mitochondrial bioenergetic capacity. 2-DG effectively prevents muscle wasting by increasing ATP synthesis efficiency via the ketone metabolic pathway and blocking the abnormal Cori cycle.

Evaluation of Geriatric Sarcopenia and Nutrition in the Case of Cachexia before Exitus: An Observational Study for Health Professionals

It is important to assess the physical and nutritional status of the body using a bioelectrical impedance analyzer (BIA) in patients with cachexia; however, the correlation between cachexia and nutritional evaluations remains unclear. The objective of this study is to follow the effects of diet therapy in patients with cachexia/sarcopenia, using parameters measured by BIA, clinical parameters, and other nutrition-related assessments in patients with osteoporosis. This study aims to clarify the correlation between BIA-measured parameters, clinical parameters, and other nutrition-related assessments. Methods: Measurements of body composition, a clinical assessment of the sarcopenia/cachexia, and nutritional goal setting/a nutrition care process were performed. Results: The number of subjects was 200, of which 15 people (7.5%) were diagnosed with sarcopenia/cachexia. Univariate analyses showed that participants with a high body-fat mass tend to develop sarcopenic obesity (p = 0.029), those who lost a significant and progressive amount of muscle mass tend to develop sarcopenia (p = 0.001), as well as those with malnutrition (p < 0.001). The regression study shows not only the correlation but also the cause of the correlation, as is the case with obesity. As obesity increases, so does the sarcopenic index (this can explain sarcopenic obesity), and as fat mass decreases it leads to muscle mass loss, increasing the risk of cachexia with age. Conclusions: There was an improvement, but statistically insignificant, in cachexia and the nutritional objectives (p > 0.05); at the same time, correlations were established between the independent parameters (sex, age) and malnutrition parameters (hemoglobin and amylase) with the parameters of the research.

Therapeutic effects of androgens for cachexia

Cachexia is a complex wasting syndrome, accompanying a variety of end-stage chronic diseases, such as cancer, heart failure and human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS). It significantly affects patients' quality of life and survival. Multiple therapeutic approaches have been studied over time. However, despite promising results, no drug has been approved to date. In this review, we examine and discuss the available data on the therapeutic effects of androgens and selective androgen receptor modulators (SARMs) for cachexia.

The systemic-level repercussions of cancer-associated inflammation mediators produced in the tumor microenvironment

The tumor microenvironment is a dynamic, complex, and redundant network of interactions between tumor, immune, and stromal cells. In this intricate environment, cells communicate through membrane-membrane, ligand-receptor, exosome, soluble factors, and transporter interactions that govern cell fate. These interactions activate the diverse and superfluous signaling pathways involved in tumor promotion and progression and induce subtle changes in the functional activity of infiltrating immune cells. The immune response participates as a selective pressure in tumor development. In the early stages of tumor development, the immune response exerts anti-tumor activity, whereas during the advanced stages, the tumor establishes mechanisms to evade the immune response, eliciting a chronic inflammation process that shows a pro-tumor effect. The deregulated inflammatory state, in addition to acting locally, also triggers systemic inflammation that has repercussions in various organs and tissues that are distant from the tumor site, causing the emergence of various symptoms designated as paraneoplastic syndromes, which compromise the response to treatment, quality of life, and survival of cancer patients. Considering the tumor-host relationship as an integral and dynamic biological system, the chronic inflammation generated by the tumor is a communication mechanism among tissues and organs that is primarily orchestrated through different signals, such as cytokines, chemokines, growth factors, and exosomes, to provide the tumor with energetic components that allow it to continue proliferating. In this review, we aim to provide a succinct overview of the involvement of cancer-related inflammation at the local and systemic level throughout tumor development and the emergence of some paraneoplastic syndromes and their main clinical manifestations. In addition, the involvement of these signals throughout tumor development will be discussed based on the physiological/biological activities of innate and adaptive immune cells. These cellular interactions require a metabolic reprogramming program for the full activation of the various cells; thus, these requirements and the by-products released into the microenvironment will be considered. In addition, the systemic impact of cancer-related proinflammatory cytokines on the liver-as a critical organ that produces the leading inflammatory markers described to date-will be summarized. Finally, the contribution of cancer-related inflammation to the development of two paraneoplastic syndromes, myelopoiesis and cachexia, will be discussed.

Baoyuan Jiedu decoction alleviating cancer cachexia–Induced muscle atrophy by regulating muscle mitochondrial function in ApcMin/+ mice

Cancer cachexia is a complex syndrome that leads to an ongoing loss of skeletal muscle mass in many malignant tumors. Our previous studies have evaluated the effectiveness of Baoyuan Jiedu decoction (BJD) in alleviating cancer-induced muscle atrophy. However, the mechanisms of BJD regulating muscle atrophy could not be fully understood. Therefore, we further investigated the mechanisms of BJD mitigating muscle atrophy both in an ApcMin/+ mouse model and the Lewis-conditioned medium–induced C2C12 myotube atrophy model. We confirmed the quality of BJD extracts by HPLC. In an In vivo study, body weight loss and muscle atrophy were alleviated with BJD treatment. GO analysis suggested that ATP metabolism and mitochondria were involved. The results of the electron microscope show that BJD treatment may have a healing effect on mitochondrial structure. Moreover, ATP content and mitochondrial numbers were improved with BJD treatment. Furthermore, both in vivo and in vitro, we demonstrated that the BJD treatment could improve mitochondrial function owing to the increased number of mitochondria, balanced dynamic, and regulation of the electron transport chain according to the protein and mRNA expressions. In addition, oxidative stress caused by mitochondrial dysfunction was ameliorated by BJD treatment in ApcMin/+ mice. Consequently, our study provides proof for BJD treatment alleviating cancer cachexia–induced muscle atrophy by modulating mitochondrial function in ApcMin/+ mice.

The importance of biological sex in cardiac cachexia

Cardiac cachexia is a catabolic muscle wasting syndrome observed in approximately 1 in 10 heart failure patients. Increased skeletal muscle atrophy leads to frailty and limits mobility which impacts quality of life, exacerbates clinical care, and is associated with higher rates of mortality. Heart failure is known to exhibit a wide range of prevalence and severity when examined across individuals of different ages and with co-morbidities related to diabetes, renal failure and pulmonary dysfunction. It is also recognized that men and women exhibit striking differences in the pathophysiology of heart failure as well as skeletal muscle homeostasis. Given that both skeletal muscle and heart failure physiology are in-part sex dependent, the diagnosis and treatment of cachexia in heart failure patients may depend on a comprehensive examination of how these organs interact. In this review we explore the potential for sex-specific differences in cardiac cachexia. We summarize advantages and disadvantages of clinical methods used to measure muscle mass and function and provide alternative measurements that should be considered in preclinical studies. Additionally, we summarize sex-dependent effects on muscle wasting in preclinical models of heart failure, disuse, and cancer. Lastly, we discuss the endocrine function of the heart and outline unanswered questions that could directly impact patient care.

The Functional Role of Long Non-Coding RNA in Myogenesis and Skeletal Muscle Atrophy

Skeletal muscle is a pivotal organ in humans that maintains locomotion and homeostasis. Muscle atrophy caused by sarcopenia and cachexia, which results in reduced muscle mass and impaired skeletal muscle function, is a serious health condition that decreases life longevity in humans. Recent studies have revealed the molecular mechanisms by which long non-coding RNAs (lncRNAs) regulate skeletal muscle mass and function through transcriptional regulation, fiber-type switching, and skeletal muscle cell proliferation. In addition, lncRNAs function as natural inhibitors of microRNAs and induce muscle hypertrophy or atrophy. Intriguingly, muscle atrophy modifies the expression of thousands of lncRNAs. Therefore, although their exact functions have not yet been fully elucidated, various novel lncRNAs associated with muscle atrophy have been identified. Here, we comprehensively review recent knowledge on the regulatory roles of lncRNAs in skeletal muscle atrophy. In addition, we discuss the issues and possibilities of targeting lncRNAs as a treatment for skeletal muscle atrophy and muscle wasting disorders in humans.

Primary Tumor Fluorine‐18 Fluorodeoxydglucose (18F‐FDG) Is Associated With Cancer-Associated Weight Loss in Non-Small Cell Lung Cancer (NSCLC) and Portends Worse Survival

Aim

To investigate the diagnostic potential of and associations between tumor ¹⁸F‐FDG uptake on PET imaging and cancer-associated weight loss.

Methods

774 non-small cell lung cancer (NSCLC) patients with pre-treatment PET evaluated between 2006 and 2014 were identified. Using the international validated definition of cachexia, the presence of clinically significant pretreatment cancer-associated weight loss (WL) was retrospectively determined. Maximum Standardized Uptake Value (SUV_Max) of ¹⁸F‐FDG was recorded and dichotomized based on 3 experimental cutpoints for survival analyses. Each SUV_Max cutpoint prioritized either survival differences, total cohort comparison sample sizes, or sample size by stage. Patient outcomes and associations between SUV_Max and cancer-associated weight loss were assessed by multivariate, categorical, and survival analyses.

Results

Patients were found to have an increased likelihood of having WL at diagnosis associated with increasing primary tumor SUV_Max after controlling for potentially confounding patient and tumor characteristics on multivariate logistic regression (OR 1.038; 95% CI: 1.012, 1.064; P=0.0037). After stratifying the cohort by WL and dichotomized SUV_Max, both factors were found to be relevant in predicting survival outcomes when the alternative variable was constant. Of note, the most striking survival differences contributed by WL status occurred in high SUV_Max groups, where the presence of WL predicted a median survival time detriment of up to 10 months, significant regardless of cutpoint determination method applied to categorize high SUV_Max patients. SUV_Max classification was found to be most consistently relevant in both WL and no WL groups.

Conclusions

The significant positive association between significant pretreatment cancer-associated weight loss and primary tumor SUV_Max underscores increased glucose uptake as a component of catabolic tumor phenotypes. This substantiates ¹⁸F‐FDG PET analysis as a prospective tool for assessment of cancer-associated weight loss and corresponding survival outcomes. Furthermore, the survival differences observed between WL groups across multiple SUV_Max classifications supports the importance of weight loss monitoring in oncologic workups. Weight loss in the setting of NSCLCs with higher metabolic activity as determined by ¹⁸F‐FDG PET signal should encourage more aggressive and earlier palliative care interventions.

The Molecular Basis and Therapeutic Potential of Leukemia Inhibitory Factor in Cancer Cachexia

Simple Summary

The mechanism of cancer cachexia is linked to a variety of factors, and inflammatory factors are thought to play a key role. We summarize the main roles of LIF in the development of cancer cachexia, including promoting fat loss, inducing skeletal muscle atrophy and causing anorexia nervosa. The main aim of this review is to increase the understanding of the effects of LIF in cachexia and to provide new insights into the treatment of cancer cachexia.

Abstract

Cachexia is a chronic metabolic syndrome that is characterized by sustained weight and muscle mass loss and anorexia. Cachexia can be secondary to a variety of diseases and affects the prognosis of patients significantly. The increase in inflammatory cytokines in plasma is deeply related to the occurrence of cachexia. As a member of the IL-6 cytokine family, leukemia inhibitory factor (LIF) exerts multiple biological functions. LIF is over-expressed in the cancer cells and stromal cells of various tumors, promoting the malignant development of tumors via the autocrine and paracrine systems. Intriguingly, increasing studies have confirmed that LIF contributes to the progression of cachexia, especially in patients with metastatic tumors. This review combines all of the evidence to summarize the mechanism of LIF-induced cachexia from the following four aspects: (i) LIF and cancer-associated cachexia, (ii) LIF and alterations of adipose tissue in cachexia, (iii) LIF and anorexia nervosa in cachexia, and (iv) LIF and muscle atrophy in cachexia. Considering the complex mechanisms in cachexia, we also focus on the interactions between LIF and other key cytokines in cachexia and existing therapeutics targeting LIF.

A comparison of nutritional status in patients with neuroblastoma in Rwanda and United Kingdom: a cross-sectional observational study conducted by the OxPLORE collaboration

Background

Cancer is a major global health concern and a leading cause of death in paediatric populations worldwide. Malnutrition contributes to a poor prognosis and remains the most common comorbidity leading to death in children with cancer. This retrospective study was developed through Oxford Paediatrics Linking Oncology Research with Electives (OxPLORE)—a medical student-led collaboration of paediatric surgeons and oncologists from low- and middle-income (LMIC) and high-income (HIC) countries. The aim of this study was twofold; firstly, to investigate the nutritional status and outcomes of neuroblastoma paediatric patients in two OxPLORE centres. Secondly, to facilitate the development of research skills of medical students as part of the OxPLORE initiative.

Results

Nine neuroblastoma patients were identified (YY, n = 4, XX, n = 5) over the study period. Nutritional status was poorer in YY patients (median z-score − 1.57 cf. − 0.7, t = 1.16, p = 0.28), which correlated with poorer survival in the YY cohort (75%), as compared to the XX cohort (100%). YY patients were older at presentation than the XX cohort (57 cf. 13 months, t = 1.959 p = 0.09). Further, tumour presentation was at a later stage in the YY group (75% stage IV).

Conclusion

This collaboration has shown a correlation in disparities in nutritional status and outcome of neuroblastoma in paediatric populations in YY and XX. These findings can inform institutional quality improvement. Further, this pilot study has highlighted the potential for medical students to undertake international research collaborations.