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Cancer alters the function of multiple organs beyond those targeted by metastasis1,2. Here we show that inflammation, fatty liver and dysregulated metabolism are hallmarks of systemically affected livers in mouse models and in patients with extrahepatic metastasis. We identified tumour-derived extracellular vesicles and particles (EVPs) as crucial mediators of cancer-induced hepatic reprogramming, which could be reversed by reducing tumour EVP secretion via depletion of Rab27a. All EVP subpopulations, exosomes and principally exomeres, could dysregulate hepatic function. The fatty acid cargo of tumour EVPs-particularly palmitic acid-induced secretion of tumour necrosis factor (TNF) by Kupffer cells, generating a pro-inflammatory microenvironment, suppressing fatty acid metabolism and oxidative phosphorylation, and promoting fatty liver formation. Notably, Kupffer cell ablation or TNF blockade markedly decreased tumour-induced fatty liver generation. Tumour implantation or pre-treatment with tumour EVPs diminished cytochrome P450 gene expression and attenuated drug metabolism in a TNF-dependent manner. We also observed fatty liver and decreased cytochrome P450 expression at diagnosis in tumour-free livers of patients with pancreatic cancer who later developed extrahepatic metastasis, highlighting the clinical relevance of our findings. Notably, tumour EVP education enhanced side effects of chemotherapy, including bone marrow suppression and cardiotoxicity, suggesting that metabolic reprogramming of the liver by tumour-derived EVPs may limit chemotherapy tolerance in patients with cancer. Our results reveal how tumour-derived EVPs dysregulate hepatic function and their targetable potential, alongside TNF inhibition, for preventing fatty liver formation and enhancing the efficacy of chemotherapy.
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Vesículas Extracelulares , Ácidos Graxos , Fígado Gorduroso , Fígado , Neoplasias Pancreáticas , Animais , Camundongos , Sistema Enzimático do Citocromo P-450/genética , Vesículas Extracelulares/metabolismo , Ácidos Graxos/metabolismo , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/prevenção & controle , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Microambiente Tumoral , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo , Neoplasias Hepáticas/secundário , Humanos , Inflamação/metabolismo , Ácido Palmítico/metabolismo , Células de Kupffer , Fosforilação Oxidativa , Proteínas rab27 de Ligação ao GTP/deficiênciaRESUMO
BACKGROUND: Occupational injuries and disability are a source of surgeon morbidity. The purpose of this study was to assess the physical toll of working in operating rooms by Canadian vascular surgeons. OBJECTIVE: To assess workplace musculoskeletal (MSK) complaints and challenges faced by Canadian vascular surgeons and trainees and their implications on surgical practice and occupational longevity. METHODS: An online survey was distributed to resident and surgeon members of the Canadian Society of Vascular Surgery. The survey collected data on demographics, operative volume, and work-related MSK symptoms. RESULTS: The survey was distributed to 188 surgeons and trainees. After three e-mailings, 109 surveys were returned (58% response rate). Of the responders, 87% were male, 51% were 45 years or older, and 56% had been in practice for 10 or more years. Workplace MSK symptoms were reported by 83% of the responders. The most common locations were the low back (78%), neck (74%), and shoulder (30%). Most responders (83%) believed that these symptoms were related to their operative environment. Almost half (48%) sought medical care. As a result of these MSK symptoms, 25% experience chronic pain with 8% reporting time off work as a consequence. Another 11% reported an impact on their operative performance with 14% considering early retirement. A lack of operating room system changes to prevent workplace injury and disability was noted by 85% of the responders although only 3% reported their disability to their department. CONCLUSIONS: Occupational MSK symptoms and disability are common among Canadian vascular surgeons. Further research is needed to create programs to improve surgeon morbidity.
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Dor Musculoesquelética , Doenças Profissionais , Cirurgiões , Adulto , Canadá/epidemiologia , Ergonomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Musculoesquelética/diagnóstico , Dor Musculoesquelética/epidemiologia , Dor Musculoesquelética/etiologia , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Prevalência , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Compared with single-incision (SI) distal biceps repair, double-incision (DI) repair has been described as permitting a more anatomic repair. We hypothesized that DI repair would result in greater terminal supination torque compared with SI repair for acute distal biceps ruptures. METHODS: Patients were included if they sustained an isolated, acute distal biceps rupture repaired between January 2012 and December 2017. Isometric forearm supination torque in 4 positions was measured using a validated uniaxial torque-testing device. Testing took place at least 12 months from surgery. The primary outcome was supination torque in the 60° supinated position. Secondary outcomes included supination torque in other forearm positions and functional outcome scores. RESULTS: The study included 37 patients: 15 underwent repair with the DI technique and 22 with the SI technique. The mean age was 47.3 years, the median follow-up time was 28.1 months, and demographic data were similar between cohorts. Mean supination torque, relative to the unaffected side, was 61% (95% confidence interval, 45%-77%) for DI repair vs. 80% (95% confidence interval, 69%-92%) for SI repair in the 60° supinated position (P = .036). In a multivariable linear regression model controlling for arm dominance, age, follow-up time, and workers' compensation status; SI repair was associated with greater mean supination torque than DI repair by 20% (P = .015). CONCLUSIONS: Contrary to our hypothesis, we found a 20% mean improvement in terminal supination torque for acute distal biceps ruptures repaired with the SI technique compared with the DI technique. This finding may have clinical significance for the more discerning, high-demand patient.
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Supinação/fisiologia , Traumatismos dos Tendões/fisiopatologia , Traumatismos dos Tendões/cirurgia , Torque , Adulto , Braço , Antebraço/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético , Procedimentos Ortopédicos/métodos , Ruptura/fisiopatologia , Ruptura/cirurgiaAssuntos
Neoplasias , Condicionamento Físico Animal , Adolescente , Animais , Terapia por Exercício , Humanos , RatosRESUMO
Purpose: Despite the advances of modern operating rooms, surgeons often experience work environments that rival those of industrial workers with regard to the risk of musculoskeletal (MSK) injuries or disorders. Such injuries may result in loss of hours, decreased surgical volume, or premature retirement. This study aimed to investigate the prevalence and impact of MSK injuries among Canadian plastic surgeons and trainees. Methods: A cross-sectional, online survey was disseminated among Canadian plastic surgeons, defined as those registered as members of the Canadian Society of Plastic Surgeons, the Royal College of Physicians and Surgeons of Canada, or Plastic Surgery Residents. Results: This survey was disseminated to 604 Canadian plastic surgeons, fellows, and residents, of whom 139 responded (response rate 23.0%). Of the responders, 49.6% were male, 23.0% were >35 years of age, and 46.1% had been in practice for >10 years. The majority (72.7%) of respondents endorsed experiencing MSK symptoms after operating. Moreover, 18.7% of respondents felt their MSK symptoms had direct consequences on their performance as a surgeon. When MSK symptoms were reported to department heads, system change was only seen 44.4% of the time. Unsurprisingly, neck (76.2%), back (72.2%), and shoulders (48.5%) were the areas of pain most reported. Exercise was not shown to significantly reduce the impact of MSK symptoms resulting from operating (P = .06). Conclusions: Musculoskeletal symptoms are common among plastic surgeons and directly impact the performance of a large proportion of surgeons. Besides traditional efforts to reinforce good posture while operating, best practice policies and operating room optimization with regard to ergonomics are warranted.
Objectif: En dépit des progrès des salles d'opération modernes, les chirurgiens sont souvent confrontés à des environnements professionnels qui rappellent ceux des travailleurs de l'industrie pour ce qui concerne le risque de blessures et de troubles musculosquelettiques. De telles lésions peuvent se traduire par une perte d'heures, une baisse du volume des interventions chirurgicales ou une retraite prématurée. Cette étude visait à étudier la prévalence et les répercussions de lésions musculosquelettiques chez les chirurgiens et stagiaires en chirurgie plastique. Méthodes: Une enquête transversale en ligne a été envoyée à des chirurgiens plasticiens, définis comme membres de la Société canadienne des chirurgiens plasticiens, du Collège royal des médecins et chirurgiens du Canada et résidents en chirurgie plastique. Résultats: Cette enquête a été envoyée à 604 chirurgiens plasticiens, fellows et résidents et 139 d'entre eux ont répondu (taux de réponse de 23,0 %). Parmi les répondants, 49,6 % étaient des hommes, 23 % avaient plus de 35 ans et 46,1 % pratiquaient depuis plus de 10 ans. La majorité (72,7 %) des répondants a reconnu avoir éprouvé des symptômes musculosquelettiques après avoir opéré. De plus, 18,7 % des répondants ont estimé que leurs symptômes musculosquelettiques avaient des répercussions directes sur leur performance en tant que chirurgiens. Quand des symptômes musculosquelettiques ont été signalés aux responsables de départements, un changement n'a été observé dans le système que dans 44,4 % des cas. De façon non surprenante, les zones douloureuses le plus souvent signalées étaient le cou (76,2 %), le dos (72,2 %) et les épaules (48,5 %). L'activité physique n'a pas semblé réduire significativement l'impact des symptômes musculosquelettiques secondaires aux interventions (P = 0,06). Conclusions: Les symptômes musculosquelettiques sont fréquents chez les chirurgiens plasticiens et ont des répercussions directes sur les performances d'un important pourcentage de chirurgiens. À côté des efforts traditionnels pour renforcer une bonne posture pendant les opérations, les meilleurs politiques en matière de pratique et l'optimisation des salles d'opération en termes d'ergonomie sont justifiées.
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Aerobic exercise training (AET) has emerged as a strategy to reduce cancer mortality, however, the mechanisms explaining AET on tumor development remain unclear. Tumors escape immune detection by generating immunosuppressive microenvironments and impaired T cell function, which is associated with T cell mitochondrial loss. AET improves mitochondrial content and function, thus we tested whether AET would modulate mitochondrial metabolism in tumor-infiltrating lymphocytes (TIL). Balb/c mice were subjected to a treadmill AET protocol prior to CT26 colon carcinoma cells injection and until tumor harvest. Tissue hypoxia, TIL infiltration and effector function, and mitochondrial content, morphology and function were evaluated. AET reduced tumor growth, improved survival, and decreased tumor hypoxia. An increased CD8+ TIL infiltration, IFN-γ and ATP production promoted by AET was correlated with reduced mitochondrial loss in these cells. Collectively, AET decreases tumor growth partially by increasing CD8+ TIL effector function through an improvement in their mitochondrial content and function.
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As spaceflight becomes more common with commercial crews, blood-based measures of crew health can guide both astronaut biomedicine and countermeasures. By profiling plasma proteins, metabolites, and extracellular vesicles/particles (EVPs) from the SpaceX Inspiration4 crew, we generated "spaceflight secretome profiles," which showed significant differences in coagulation, oxidative stress, and brain-enriched proteins. While >93% of differentially abundant proteins (DAPs) in vesicles and metabolites recovered within six months, the majority (73%) of plasma DAPs were still perturbed post-flight. Moreover, these proteomic alterations correlated better with peripheral blood mononuclear cells than whole blood, suggesting that immune cells contribute more DAPs than erythrocytes. Finally, to discern possible mechanisms leading to brain-enriched protein detection and blood-brain barrier (BBB) disruption, we examined protein changes in dissected brains of spaceflight mice, which showed increases in PECAM-1, a marker of BBB integrity. These data highlight how even short-duration spaceflight can disrupt human and murine physiology and identify spaceflight biomarkers that can guide countermeasure development.
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Coagulação Sanguínea , Barreira Hematoencefálica , Encéfalo , Homeostase , Estresse Oxidativo , Voo Espacial , Animais , Humanos , Encéfalo/metabolismo , Barreira Hematoencefálica/metabolismo , Camundongos , Coagulação Sanguínea/fisiologia , Masculino , Secretoma/metabolismo , Camundongos Endogâmicos C57BL , Vesículas Extracelulares/metabolismo , Proteômica/métodos , Biomarcadores/metabolismo , Biomarcadores/sangue , Feminino , Adulto , Proteínas Sanguíneas/metabolismo , Pessoa de Meia-Idade , Leucócitos Mononucleares/metabolismo , Proteoma/metabolismoRESUMO
We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) (6.4 g day⻹) was ingested for 4 weeks and 500 mg kg⻹ BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation, the athletes completed four 30-s upper-body Wingate tests, separated by 3 min. Blood lactate was determined at rest, immediately after and 5 min after the 4th exercise bout, with perceived exertion reported immediately after the 4th bout. BA and SB alone increased the total work done in +7 and 8 %, respectively. The co-ingestion resulted in an additive effect (+14 %, p < 0.05 vs. BA and SB alone). BA alone significantly improved mean power in the 2nd and 3rd bouts and tended to improve the 4th bout. SB alone significantly improved mean power in the 4th bout and tended to improve in the 2nd and 3rd bouts. BA+SB enhanced mean power in all four bouts. PL+PL did not elicit any alteration on mean and peak power. Post-exercise blood lactate increased with all treatments except with PL+PL. Only BA+SB resulted in lower ratings of perceived exertion (p = 0.05). Chronic BA and SB supplementation alone equally enhanced high-intensity intermittent upper-body performance in well-trained athletes. Combined BA and SB promoted a clear additive ergogenic effect.
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Acidose/prevenção & controle , Desempenho Atlético , Carbonato de Cálcio/farmacologia , Artes Marciais , Fadiga Muscular/efeitos dos fármacos , Bicarbonato de Sódio/farmacologia , beta-Alanina/farmacologia , Acidose/tratamento farmacológico , Acidose/metabolismo , Adulto , Atletas , Carbonato de Cálcio/administração & dosagem , Carbonato de Cálcio/efeitos adversos , Suplementos Nutricionais , Método Duplo-Cego , Teste de Esforço , Humanos , Ácido Láctico/sangue , Masculino , Destreza Motora/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Esforço Físico , Bicarbonato de Sódio/administração & dosagem , Bicarbonato de Sódio/efeitos adversos , Extremidade Superior/fisiologia , Adulto Jovem , beta-Alanina/administração & dosagem , beta-Alanina/efeitos adversosRESUMO
Over the past decade, extracellular vesicles and particles (EVPs) have emerged as critical mediators of intercellular communication, participating in numerous physiological and pathological processes. In the context of cancer, EVPs exert local effects, such as increased invasiveness, motility, and reprogramming of tumor stroma, as well as systemic effects, including pre-metastatic niche formation, determining organotropism, promoting metastasis and altering the homeostasis of various organs and systems, such as the liver, muscle, and circulatory system. This review provides an overview of the critical advances in EVP research during the past decade, highlighting the heterogeneity of EVPs, their roles in intercellular communication, cancer progression, and metastasis. Moreover, the clinical potential of systemic EVPs as useful cancer biomarkers and therapeutic agents is explored. Last but not least, the progress in EVP analysis technologies that have facilitated these discoveries is discussed, which may further propel EVP research in the future.
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Exercise training reduces the incidence of several cancers, but the mechanisms underlying these effects are not fully understood. Exercise training can affect the spleen function, which controls the hematopoiesis and immune response. Analyzing different cancer models, we identified that 4T1, LLC, and CT26 tumor-bearing mice displayed enlarged spleen (splenomegaly), and exercise training reduced spleen mass toward control levels in two of these models (LLC and CT26). Exercise training also slowed tumor growth in melanoma B16F10, colon tumor 26 (CT26), and Lewis lung carcinoma (LLC) tumor-bearing mice, with minor effects in mammary carcinoma 4T1, MDA-MB-231, and MMTV-PyMT mice. In silico analyses using transcriptome profiles derived from these models revealed that platelet factor 4 (Pf4) is one of the main upregulated genes associated with splenomegaly during cancer progression. To understand whether exercise training would modulate the expression of these genes in the tumor and spleen, we investigated particularly the CT26 model, which displayed splenomegaly and had a clear response to the exercise training effects. RT-qPCR analysis confirmed that trained CT26 tumor-bearing mice had decreased Pf4 mRNA levels in both the tumor and spleen when compared to untrained CT26 tumor-bearing mice. Furthermore, exercise training specifically decreased Pf4 mRNA levels in the CT26 tumor cells. Aspirin treatment did not change tumor growth, splenomegaly, and tumor Pf4 mRNA levels, confirming that exercise decreased non-platelet Pf4 mRNA levels. Finally, tumor Pf4 mRNA levels are deregulated in The Cancer Genome Atlas Program (TCGA) samples and predict survival in multiple cancer types. This highlights the potential therapeutic value of exercise as a complementary approach to cancer treatment and underscores the importance of understanding the exercise-induced transcriptional changes in the spleen for the development of novel cancer therapies.
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Carcinoma Pulmonar de Lewis , Neoplasias do Colo , Exercício Físico , Fator Plaquetário 4 , Animais , Camundongos , Inibidores da Angiogênese , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/terapia , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Fatores Imunológicos , Camundongos Endogâmicos BALB C , Fator Plaquetário 4/genética , RNA Mensageiro , Esplenomegalia/metabolismo , Exercício Físico/fisiologiaRESUMO
The purpose of this study was to determine the physiological, anthropometric, performance, and nutritional characteristics of the Brazil Canoe Polo National Team. Ten male canoe polo athletes (age 26.7 ± 4.1 years) performed a battery of tests including assessments of anthropometric parameters, upper-body anaerobic power (Wingate), muscular strength, aerobic power, and nutritional profile. In addition, we characterized heart rate and plasma lactate responses and the temporal pattern of the effort/recovery during a simulated canoe polo match. The main results are as follows: body fat, 12.3 ± 4.0%; upper-body peak and mean power, 6.8 ± 0.5 and 4.7 ± 0.4 W · kg(-1), respectively; 1-RM bench press, 99.1 ± 11.7 kg; peak oxygen uptake, 44.3 ± 5.8 mL · kg(-1) · min(-1); total energy intake, 42.8 ± 8.6 kcal · kg(-1); protein, carbohydrate, and fat intakes, 1.9 ± 0.1, 5.0 ± 1.5, and 1.7 ± 0.4 g · kg(-1), respectively; mean heart rate, 146 ± 11 beats · min(-1); plasma lactate, 5.7 ± 3.8 mmol · L(-1) at half-time and 4.6 ± 2.2 mmol · L(-1) at the end of the match; effort time (relative to total match time), 93.1 ± 3.0%; number of sprints, 9.6 ± 4.4. The results of this study will assist coaches, trainers, and nutritionists in developing more adequate training programmes and dietary interventions for canoe polo athletes.
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Antropometria , Atletas , Desempenho Atlético/fisiologia , Estado Nutricional , Tecido Adiposo , Adolescente , Adulto , Composição Corporal/fisiologia , Brasil , Alimentos , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , Navios , Adulto JovemRESUMO
Cancer cachexia is a multifactorial and devastating syndrome characterized by severe skeletal muscle mass loss and dysfunction. As cachexia still has neither a cure nor an effective treatment, better understanding of skeletal muscle plasticity in the context of cancer is of great importance. Although aerobic exercise training (AET) has been shown as an important complementary therapy for chronic diseases and associated comorbidities, the impact of AET on skeletal muscle mass maintenance during cancer progression has not been well documented yet. Here, we show that previous AET induced a protective mechanism against tumor-induced muscle wasting by modulating the Akt/mTORC1 signaling and eukaryotic initiation factors, specifically eIF2-α. Thereafter, it was determined whether the in vivo Akt activation would induce a hypertrophic profile in cachectic muscles. As observed for the first time, Akt-induced hypertrophy was able and sufficient to either prevent or revert cancer cachexia by modulating both Akt/mTORC1 pathway and the eIF-2α activation, and induced a better muscle functionality. These findings provide evidence that skeletal muscle tissue still preserves hypertrophic potential to be stimulated by either AET or gene therapy to counteract cancer cachexia.
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We investigated the effects of AET on myomiRs expression in the skeletal muscle and serum of colon cachectic (CT26) and breast non-cachectic (MMTV-PyMT) cancer mice models. Colon cancer decreased microRNA-486 expression, increasing PTEN in tibialis anterior muscle (TA), decreasing the PI3K/mTOR protein pathway, body and muscle wasting, fibers' cross-sectional area and muscle dysfunction, that were not preserved by AET. In contrast, breast cancer decreased those muscle functions, but were preserved by AET. In circulation, the downregulation of microRNA-486 and -206 in colon cancer, and the downregulation of microRNA-486 and upregulation of microRNA-206 expression in breast cancer might be good cancer serum biomarkers. Since the microRNA-206 is skeletal muscle specific, their expression was increased in the TA, serum and tumor in MMTV, suggesting a communication among these three compartments. The AET prevents these effects on microRNA-206, but not on microRNA-486 in MMTV. In conclusion, cancer induced a downregulation of microRNA-486 expression in TA and serum of CT26 and MMTV mice and these effects were not prevented by AET; however, to MMTV, the trained muscle function was preserved, probably sustained by the downregulation of microRNA-206 expression. Serum microRNA-206 is a potential biomarker for colon (decreased) and breast (increased) cancer to monitor the disease evolution and the effects promoted by the AET.
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We developed a modified protocol, based on differential ultracentrifugation (dUC), to isolate extracellular vesicles and particles (specifically exomeres) (EVPs) from various human and murine sources, including cell lines, surgically resected tumors and adjacent tissues, and bodily fluids, such as blood, lymphatic fluid, and bile. The diversity of these samples requires robust and highly reproducible protocols and refined isolation technology, such as asymmetric-flow field-flow fractionation (AF4). Our isolation protocol allows for preparation of EVPs for various downstream applications, including proteomic profiling. For complete details on the use and execution of this protocol, please refer to Hoshino et al. (2020).
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Líquidos Corporais/química , Centrifugação com Gradiente de Concentração , Vesículas Extracelulares/química , Fracionamento por Campo e Fluxo , Proteômica , Animais , Linhagem Celular , Humanos , CamundongosRESUMO
OBJECTIVE: We tested the hypothesis that exercise training would attenuate metabolic impairment in a model of severe cancer cachexia. METHODS: We used multiple in vivo and in vitro methods to explore the mechanisms underlying the beneficial effects induced by exercise training in tumor-bearing rats. RESULTS: Exercise training improved running capacity, prolonged lifespan, reduced oxidative stress, and normalized muscle mass and contractile function in tumor-bearing rats. An unbiased proteomic screening revealed COP9 signalosome complex subunit 2 (COPS2) as one of the most downregulated proteins in skeletal muscle at the early stage of cancer cachexia. Exercise training normalized muscle COPS2 protein expression in tumor-bearing rats and mice. Lung cancer patients with low endurance capacity had low muscle COPS2 protein expression as compared to age-matched control subjects. To test whether decrease in COPS2 protein levels could aggravate or be an intrinsic compensatory mechanism to protect myotubes from cancer effects, we performed experiments in vitro using primary myotubes. COPS2 knockdown in human myotubes affected multiple cellular pathways, including regulation of actin cytoskeleton. Incubation of cancer-conditioned media in mouse myotubes decreased F-actin expression, which was partially restored by COPS2 knockdown. Direct repeat 4 (DR4) response elements have been shown to positively regulate gene expression. COPS2 overexpression decreased the DR4 activity in mouse myoblasts, and COPS2 knockdown inhibited the effects of cancer-conditioned media on DR4 activity. CONCLUSIONS: These studies demonstrated that exercise training may be an important adjuvant therapy to counteract cancer cachexia and uncovered novel mechanisms involving COPS2 to regulate myotube homeostasis in cancer cachexia.