Aerobic Exercise Ameliorates Cancer Cachexia-Induced Muscle Wasting through Adiponectin Signaling

Restoring adiponectin via rosiglitazone ameliorates tissue wasting in mice with lung cancer

AIM

To investigate systemic regulators of the cancer-associated cachexia syndrome (CACS) in a pre-clinical model for lung cancer with the goal to identify therapeutic targets for tissue wasting.

METHODS

Using the Kras/Lkb1 (KL) mouse model, we found that CACS is associated with white adipose tissue (WAT) dysfunction that directly affects skeletal muscle homeostasis. WAT transcriptomes showed evidence of reduced adipogenesis, and, in agreement, we found low levels of circulating adiponectin. To preserve adipogenesis and restore adiponectin levels, we treated mice with the PPAR-γ agonist, rosiglitazone.

RESULTS

Rosiglitazone treatment increased serum adiponectin levels, delayed weight loss, and preserved skeletal muscle and adipose tissue mass, as compared to vehicle-treated mice. The preservation of muscle mass with rosiglitazone was associated with increases in AMPK and AKT activity. Similarly, activation of the adiponectin receptors in muscle cells increased AMPK activity, anabolic signaling, and protein synthesis.

CONCLUSION

Our data suggest that PPAR-γ agonists may be a useful adjuvant therapy to preserve tissue mass in lung cancer.

Molecular mechanisms of cancer cachexia. Role of exercise training

Cancer-associated cachexia represents a multifactorial syndrome mainly characterized by muscle mass loss, which causes both a decrease in quality of life and anti-cancer therapy failure, among other consequences. The definition and diagnostic criteria of cachexia have changed and improved over time, including three different stages (pre-cachexia, cachexia, and refractory cachexia) and objective diagnostic markers. This metabolic wasting syndrome is characterized by a negative protein balance, and anti-cancer drugs like chemotherapy or immunotherapy exacerbate it through relatively unknown mechanisms. Due to its complexity, cachexia management involves a multidisciplinary strategy including not only nutritional and pharmacological interventions. Physical exercise has been proposed as a strategy to counteract the effects of cachexia on skeletal muscle, as it influences the mechanisms involved in the disease such as protein turnover, inflammation, oxidative stress, and mitochondrial dysfunction. This review will summarize the experimental and clinical evidence of the impact of physical exercise on cancer-associated cachexia.

Influence of Amino Acids and Exercise on Muscle Protein Turnover, Particularly in Cancer Cachexia

Cancer cachexia is a multifaceted syndrome that impacts individuals with advanced cancer. It causes numerous pathological changes in cancer patients, such as inflammation and metabolic dysfunction, which further diminish their quality of life. Unfortunately, cancer cachexia also increases the risk of mortality in affected individuals, making it an important area of focus for cancer research and treatment. Several potential nutritional therapies are being tested in preclinical and clinical models for their efficacy in improving muscle metabolism in cancer patients. Despite promising results, no special nutritional therapies have yet been validated in clinical practice. Multiple studies provide evidence of the benefits of increasing muscle protein synthesis through an increased intake of amino acids or protein. There is also increasing evidence that exercise can reduce muscle atrophy by modulating protein synthesis. Therefore, the combination of protein intake and exercise may be more effective in improving cancer cachexia. This review provides an overview of the preclinical and clinical approaches for the use of amino acids with and without exercise therapy to improve muscle metabolism in cachexia.

AMPK as a mediator of tissue preservation: time for a shift in dogma?

Ground-breaking discoveries have established 5'-AMP-activated protein kinase (AMPK) as a central sensor of metabolic stress in cells and tissues. AMPK is activated through cellular starvation, exercise and drugs by either directly or indirectly affecting the intracellular AMP (or ADP) to ATP ratio. In turn, AMPK regulates multiple processes of cell metabolism, such as the maintenance of cellular ATP levels, via the regulation of fatty acid oxidation, glucose uptake, glycolysis, autophagy, mitochondrial biogenesis and degradation, and insulin sensitivity. Moreover, AMPK inhibits anabolic processes, such as lipogenesis and protein synthesis. These findings support the notion that AMPK is a crucial regulator of cell catabolism. However, studies have revealed that AMPK's role in cell homeostasis might not be as unidirectional as originally thought. This Review explores emerging evidence for AMPK as a promoter of cell survival and an enhancer of anabolic capacity in skeletal muscle and adipose tissue during catabolic crises. We discuss AMPK-activating interventions for tissue preservation during tissue wasting in cancer-associated cachexia and explore the clinical potential of AMPK activation in wasting conditions. Overall, we provide arguments that call for a shift in the current dogma of AMPK as a mere regulator of cell catabolism, concluding that AMPK has an unexpected role in tissue preservation.

Advancing cancer cachexia diagnosis with -omics technology and exercise as molecular medicine

Muscle atrophy exacerbates disease outcomes and increases mortality, whereas the preservation of skeletal muscle mass and function play pivotal roles in ensuring long-term health and overall quality-of-life. Muscle atrophy represents a significant clinical challenge, involving the continued loss of muscle mass and strength, which frequently accompany the development of numerous types of cancer. Cancer cachexia is a highly prevalent multifactorial syndrome, and although cachexia is one of the main causes of cancer-related deaths, there are still no approved management strategies for the disease. The etiology of this condition is based on the upregulation of systemic inflammation factors and catabolic stimuli, resulting in the inhibition of protein synthesis and enhancement of protein degradation. Numerous necessary cellular processes are disrupted by cachectic pathology, which mediate intracellular signalling pathways resulting in the net loss of muscle and organelles. However, the exact underpinning molecular mechanisms of how these changes are orchestrated are incompletely understood. Much work is still required, but structured exercise has the capacity to counteract numerous detrimental effects linked to cancer cachexia. Primarily through the stimulation of muscle protein synthesis, enhancement of mitochondrial function, and the release of myokines. As a result, muscle mass and strength increase, leading to improved mobility, and quality-of-life. This review summarises existing knowledge of the complex molecular networks that regulate cancer cachexia and exercise, highlighting the molecular interplay between the two for potential therapeutic intervention. Finally, the utility of mass spectrometry-based proteomics is considered as a way of establishing early diagnostic biomarkers of cachectic patients.

Cancer cachexia: Focus on cachexia factors and inter-organ communication

ABSTRACT

Cancer cachexia is a multi-organ syndrome and closely related to changes in signal communication between organs, which is mediated by cancer cachexia factors. Cancer cachexia factors, being the general name of inflammatory factors, circulating proteins, metabolites, and microRNA secreted by tumor or host cells, play a role in secretory or other organs and mediate complex signal communication between organs during cancer cachexia. Cancer cachexia factors are also a potential target for the diagnosis and treatment. The pathogenesis of cachexia is unclear and no clear effective treatment is available. Thus, the treatment of cancer cachexia from the perspective of the tumor ecosystem rather than from the perspective of a single molecule and a single organ is urgently needed. From the point of signal communication between organs mediated by cancer cachexia factors, finding a deeper understanding of the pathogenesis, diagnosis, and treatment of cancer cachexia is of great significance to improve the level of diagnosis and treatment. This review begins with cancer cachexia factors released during the interaction between tumor and host cells, and provides a comprehensive summary of the pathogenesis, diagnosis, and treatment for cancer cachexia, along with a particular sight on multi-organ signal communication mediated by cancer cachexia factors. This summary aims to deepen medical community's understanding of cancer cachexia and may conduce to the discovery of new diagnostic and therapeutic targets for cancer cachexia.

Long-term detraining reverses the improvement of lifelong exercise on skeletal muscle ferroptosis and inflammation in aging rats: fiber-type dependence of the Keap1/Nrf2 pathway

We investigated the effects of lifelong aerobic exercise and 8 months of detraining after 10 months of aerobic training on circulation, skeletal muscle oxidative stress, and inflammation in aging rats. Sprague-Dawley rats were randomly assigned to the control (CON), detraining (DET), and lifelong aerobic training (LAT) groups. The DET and LAT groups began aerobic treadmill exercise at the age of 8 months and stopped training at the 18th and 26th month, respectively; all rats were sacrificed when aged 26 months. Compared with CON, LAT remarkably decreased serum and aged skeletal muscle 4-hydroxynonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. Superoxide dismutase 2(SOD2) levels were higher in the LAT group than in the CON group in skeletal muscle. However, DET remarkably decreased SOD2 protein expression and content in the skeletal muscle and increased malondialdehyde (MDA) level compared with LAT. Compared with LAT, DET remarkably downregulated adiponectin and upregulated tumor necrosis factor alpha (TNF-α) expression, while phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and 70-kDa ribosomal protein S6 kinase (P70S6K) protein expression decreased, and that of FoxO1 and muscle atrophy F-box (MAFbX) proteins increased in the quadriceps femoris. Adiponectin and TNF-α expression in the soleus muscle did not change between groups, whereas that of AKT, mammalian target of rapamycin (mTOR), and P70S6K was lower in the soleus in the DET group than in that in the LAT group. Compared with that in the LAT group, sestrin1 (SES1) and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression in the DET group was lower, whereas Keap1 mRNA expression was remarkably upregulated in the quadriceps femoris. Interestingly, the protein and mRNA levels of SES1, Nrf2, and Keap1 in soleus muscle did not differ between groups. LAT remarkably upregulated ferritin heavy polypeptide 1(FTH), glutathione peroxidase 4(GPX4), and solute carrier family 7member 11 (SLC7A11) protein expression in the quadriceps femoris and soleus muscles, compared with CON. However, compared with LAT, DET downregulated FTH, GPX4, and SLC7A11 protein expression in the quadriceps femoris and soleus muscles. Long-term detraining during the aging phase reverses the improvement effect of lifelong exercise on oxidative stress, inflammation, ferroptosis, and muscle atrophy in aging skeletal muscle. The quadriceps femoris is more evident than the soleus, which may be related to the different changes in the Keap1/Nrf2 pathway in different skeletal muscles.

Cancer Cachexia: Underlying Mechanisms and Potential Therapeutic Interventions

Cancer cachexia, a multifactorial metabolic syndrome developed during malignant tumor growth, is characterized by an accelerated loss of body weight accompanied by the depletion of skeletal muscle mass. This debilitating condition is associated with muscle degradation, impaired immune function, reduced functional capacity, compromised quality of life, and diminished survival in cancer patients. Despite the lack of the known capability of fully reversing or ameliorating this condition, ongoing research is shedding light on promising preclinical approaches that target the disrupted mechanisms in the pathophysiology of cancer cachexia. This comprehensive review delves into critical aspects of cancer cachexia, including its underlying pathophysiological mechanisms, preclinical models for studying the progression of cancer cachexia, methods for clinical assessment, relevant biomarkers, and potential therapeutic strategies. These discussions collectively aim to contribute to the evolving foundation for effective, multifaceted counteractive strategies against this challenging condition.

Restoring adiponectin via rosiglitazone ameliorates tissue wasting in mice with lung cancer

The cancer associated cachexia syndrome (CACS) is a systemic metabolic disorder resulting in loss of body weight due to skeletal muscle and adipose tissues atrophy. CACS is particularly prominent in lung cancer patients, where it contributes to poor quality of life and excess mortality. Using the Kras/Lkb1 (KL) mouse model, we found that CACS is associated with white adipose tissue (WAT) dysfunction that directly affects skeletal muscle homeostasis. WAT transcriptomes showed evidence of reduced adipogenesis, and, in agreement, we found low levels of circulating adiponectin. To preserve adipogenesis and restore adiponectin levels, we treated mice with the PPAR-γ agonist, rosiglitazone. Rosiglitazone treatment increased serum adiponectin levels, delayed weight loss, and preserved skeletal muscle and adipose tissue mass, as compared to vehicle-treated mice. The preservation of muscle mass with rosiglitazone was associated with increases in AMPK and AKT activity. Similarly, activation of the adiponectin receptors in muscle cells increased AMPK activity, anabolic signaling, and protein synthesis. Our data suggest that PPAR-γ agonists may be a useful adjuvant therapy to preserve tissue mass in lung cancer.

Longitudinal associations among physical activity, inflammatory markers, and quality of life in patients with head and neck cancer

INTRODUCTION

The aim of this study was to explore the associations among physical activity (PA), inflammatory markers, and quality of life (QoL) from preradiotherapy to 1-year postradiotherapy for patients with head and neck cancer (HNC).

METHODS

This was an observational longitudinal study. Mixed-effect models incorporating within-subject correlation were used to examine the relationship among the three key variables.

RESULTS

Aerobically active patients had significantly lower levels of sTNFR2 (but not other inflammatory markers) than aerobically inactive patients. Being aerobically active and lower inflammation were independently associated with better total QoL scores after adjusting covariates. The trend was similar for patients engaged in strength exercises.

CONCLUSIONS

Being aerobically active was associated with lower inflammation as represented by sTNFR2 but not with other inflammatory markers. Higher PA (aerobic and strength) and lower inflammation were linked to better QoL. More research is warranted to validate the association among PA, inflammation, and QoL.

Cancer cachexia: molecular mechanisms and treatment strategies

Muscle wasting is a consequence of physiological changes or a pathology characterized by increased catabolic activity that leads to progressive loss of skeletal muscle mass and strength. Numerous diseases, including cancer, organ failure, infection, and aging-associated diseases, are associated with muscle wasting. Cancer cachexia is a multifactorial syndrome characterized by loss of skeletal muscle mass, with or without the loss of fat mass, resulting in functional impairment and reduced quality of life. It is caused by the upregulation of systemic inflammation and catabolic stimuli, leading to inhibition of protein synthesis and enhancement of muscle catabolism. Here, we summarize the complex molecular networks that regulate muscle mass and function. Moreover, we describe complex multi-organ roles in cancer cachexia. Although cachexia is one of the main causes of cancer-related deaths, there are still no approved drugs for cancer cachexia. Thus, we compiled recent ongoing pre-clinical and clinical trials and further discussed potential therapeutic approaches for cancer cachexia.

Effects of weight-bearing vs. non-weight-bearing endurance exercise on reducing body fat and inflammatory markers in obese females

OBJECTIVES

Endurance exercise is an effective strategy for maintaining an anti-inflammatory environment and weight management. However, the effect of this type of exercise on decreasing body fat and TNF-α levels and increasing adiponectin levels is controversial. The aims of this study was to prove the effects of weight-bearing vs. non-weight-bearing endurance exercise on reducing body fat and inflammatory markers in obese females.

METHODS

24 obese adolescents were recruited from female students from the State University of Malang. The interventions given in this study were weight-bearing endurance exercise (WBEE), and non-weight-bearing endurance exercise (NWBEE). Serum TNF-α levels and serum adiponectin levels were evaluated using enzyme-linked immunosorbent assay (ELISA). Statistical analysis techniques use paired sample T-test with a significant level of 5%.

RESULTS

Results of the statistical analysis show that the average body fat (PBF, FM, FFM) and TNF-α levels before endurance exercise vs. after endurance exercise in both types of exercise experienced a significant decrease (p≤0.05), while average adiponectin levels in both types of exercise experienced a significant increase before endurance exercise vs. after endurance exercise (p≤0.001).

CONCLUSIONS

In general, it can be concluded that weight-bearing and non-weight-bearing endurance exercise with moderate-intensity for 40 min/exercise session reduce body fat and TNF-α levels and increase adiponectin levels as a marker of inflammation in obese female.

Protective effects of hachimijiogan (HJG), a Japanese Kampo medicine, on cancer cachectic muscle wasting in mice

Myogenesis is required to generate skeletal muscle tissue and to maintain skeletal muscle mass. Decreased myogenesis under various pathogenic conditions results in muscular atrophy. Through a small screening of Japanese traditional (Kampo) medicines, hachimijiogan (HJG) was shown to promote the myogenic differentiation of C2C12 myoblasts through the upregulation of myogenin. In tumor-bearing cancer-cachectic mice, HJG was also found to have a protective effect against cancer-cachectic muscle wasting. This effect was significant when HJG was administered in combination with aerobic exercise by treadmill running. Moreover, HJG ameliorated the cellular atrophy of C2C12 myotubes induced by treatment with conditioned medium derived from a colon-26 cancer cell culture. In addition, HJG suppressed H2O2-dependent myotube atrophy, suggesting that HJG could reverse the atrophic phenotypes by eliminating reactive oxygen species.

Exercise and Exercise Mimetics for the Treatment of Musculoskeletal Disorders

PURPOSE OF REVIEW

The incidence of musculoskeletal disorders affecting bones, joints, and muscles is dramatically increasing in parallel with the increased longevity of the worldwide population, severely impacting on the individual's quality of life and on the healthcare costs. Inactivity and sedentary lifestyle are nowadays considered the main drivers of age-associated musculoskeletal disorders and exercise may counteract such alterations also in other bone- and muscle-centered disorders. This review aims at clarifying the potential use of exercise training to improve musculoskeletal health.

RECENT FINDINGS

Both the skeletal muscle and the bone are involved in a complex crosstalk determining, in part through tissue-specific and inflammatory/immune released factors, the occurrence of musculoskeletal disorders. Exercise is able to modulate the levels of those molecules and several associated molecular pathways. Evidence from preclinical and clinical trials supports the adoption of exercise and the future use of exercise mimicking drugs will optimize the care of individuals with musculoskeletal disorders.

Nutritional and Exercise Interventions in Cancer-Related Cachexia: An Extensive Narrative Review

One of the common traits found in cancer patients is malnutrition and cachexia, which affects between 25% to 60% of the patients, depending on the type of cancer, diagnosis, and treatment. Given the lack of current effective pharmacological solutions for low muscle mass and sarcopenia, holistic interventions are essential to patient care, as well as exercise and nutrition. Thus, the present narrative review aimed to analyze the nutritional, pharmacological, ergonutritional, and physical exercise strategies in cancer-related cachexia. The integration of multidisciplinary interventions could help to improve the final intervention in patients, improving their prognosis, quality of life, and life expectancy. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Cancer-related cachexia is a complex multifactorial phenomenon in which systemic inflammation plays a key role in the development and maintenance of the symptomatology. Pharmacological interventions seem to produce a positive effect on inflammatory state and cachexia. Nutritional interventions are focused on a high-energy diet with high-density foods and the supplementation with antioxidants, while physical activity is focused on strength-based training. The implementation of multidisciplinary non-pharmacological interventions in cancer-related cachexia could be an important tool to improve traditional treatments and improve patients' quality of life.

Exercise protocols: The gap between preclinical and clinical exercise oncology studies

Introduction

Preclinical studies provide foundational knowledge to develop new effective treatments for use in clinical practice. Similar to clinical exercise oncology studies, it is also important to monitor, identify and/or avoid cancer-induced complications in preclinical (e.g., murine) exercise oncology studies. This may help close the gap between preclinical and clinical exercise oncology studies. The aim of the present mini review is to provide insight into exercise protocol design in preclinical exercise oncology studies in order to close the preclinical-clinical gap. A secondary aim was to examine exercise-responsive outcomes in the preclinical versus clinical setting.

Method

We reviewed animal studies in exercise oncology. A literature search was performed in PubMed/Medline and studies in English were screened.

Results

We found that the majority of preclinical exercise protocols have not been at least tested clinically. We found some evidence that certain outcomes of preclinical studies (e.g., markers of cellular and molecular adaptation) that translate to clinical studies. However, this translation was dependent on the use, by investigators in their study design, of suitable and applicable preclinical exercise protocols.

Conclusions

Cancer and its treatment-induced complications (e.g., fatigue, cardiac atrophy, cachexia, etc.) have largely been ignored in the exercise protocols of preclinical oncology studies. Preclinical exercise oncology studies should consider the limitations of human exercise oncology studies when conducting gap analysis for their study design to increase the probability that findings related to mechanistic adaptations in exercise oncology will be translatable to the clinical setting. By virtue of paying heed to patient compliance and adverse effects, clinical exercise oncology research teams must design relevant, feasible exercise protocols; researchers in preclinical exercise oncology should also take such factors into consideration in order to help bridge the gap between preclinical and clinical studies in exercise oncology.

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Preclinical research provides foundational knowledge for the development of human experimental and clinical studies; however, direct translation of preclinical findings has a low success rate.

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Exercise can provide potent wide-ranging beneficial effects for people with chronic diseases, including cancer.

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A minority of preclinical exercise oncology studies account for cancer-related factors in their experimental design.

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To lessen the preclinical–clinical gap in exercise oncology research, preclinical exercise oncology studies should consider using experimental designs that are based on locomotor activity and/or VO2peak in animals bearing cancer.

The Role of Autophagy Modulated by Exercise in Cancer Cachexia

Cancer cachexia is a syndrome experienced by many patients with cancer. Exercise can act as an autophagy modulator, and thus holds the potential to be used to treat cancer cachexia. Autophagy imbalance plays an important role in cancer cachexia, and is correlated to skeletal and cardiac muscle atrophy and energy-wasting in the liver. The molecular mechanism of autophagy modulation in different types of exercise has not yet been clearly defined. This review aims to elaborate on the role of exercise in modulating autophagy in cancer cachexia. We evaluated nine studies in the literature and found a potential correlation between the type of exercise and autophagy modulation. Combined exercise or aerobic exercise alone seems more beneficial than resistance exercise alone in cancer cachexia. Looking ahead, determining the physiological role of autophagy modulated by exercise will support the development of a new medical approach for treating cancer cachexia. In addition, the harmonization of the exercise type, intensity, and duration might play a key role in optimizing the autophagy levels to preserve muscle function and regulate energy utilization in the liver.