Project description:Cachexia is a systemic metabolic syndrome characterized by loss of fat and skeletal muscle mass in chronic wasting diseases such as cancer. The regulation of cellular protein synthesis in response to workload in skeletal muscle is generally blunted in cancer cachexia; however, the precise molecular regulation is largely unknown. In this study, to examine the molecular mechanism of skeletal muscle protein metabolism in cancer cachexia, we analyzed comprehensive gene expression in skeletal muscle using microarrays. CD2F1 mice (male, 7 weeks old) were subcutaneously transplanted (1*10^6 cells per mouse) with a mouse colon cancer-derived cell line (C26) as a model of cancer cachexia. Functional overload of the plantaris muscle by synergist ablation was performed at the 2nd week, and the plantaris muscle was sampled at the 4th week of cancer transplantation. The hypertrophy of skeletal muscle (increased skeletal muscle weight/protein synthesis efficiency and activation of mTOR signaling) associated with compensatory overload was significantly suppressed with the cancer cachexia. Gene expression profiling and pathway analysis by microarray showed that resistance to muscle protein synthesis associated with cancer cachexia was induced by downregulation of insulin-like growth factor-1. These observations show that cancer cachexia induces resistance to muscle protein synthesis, which could be a potential factor inhibiting the adaptation of skeletal muscle growth to physical exercise.
Project description:Background Loss of skeletal muscle mass in advanced cancer is recognized as an independent predictor of mortality. Mechanisms involved in this wasting process and parameters for early diagnosis are still lacking. As skeletal muscle is considered as a secretory organ, the aim of this present experimental work was to characterize the changes in muscle proteome and secretome associated with cancer-induced cachexia to better understand cellular mechanisms involved in this wasting process and to identify secreted proteins which might reflect the ongoing muscle atrophy process. Methods We investigated first the changes in the muscle proteome associated with cancer-induced cachexia by using differential label-free proteomic analysis on muscle of the C26 mouse model. The differentially abundant proteins were submitted to sequential bioinformatic secretomic analysis in order to identify potentially secreted proteins. Selected reaction monitoring and Western blotting were used to verify the presence of candidate proteins at the circulating level. Their muscle source was demonstrated by assessing their gene expression in skeletal muscle and in cultured myotubes. Finally, we also investigated their regulation in muscle cells. Alterations in several molecular pathways potentially involved in muscle atrophy were highlighted using Gene ontology enrichment analyses. Results Our results revealed a dramatic increased production (2-to 25-fold) by the muscle of several acute phase reactants (APR: Haptoglobin, Serpina3n, Complement C3, Serum amyloid A1) which are also released in the circulation during C26 cancer cachexia. Their production was confirmed in other preclinical models of cancer cachexia as well as in cancer patients. The muscular origin of these APR was demonstrated by their increased expression in skeletal muscle and myotubes. Glucocorticoids and pro-inflammatory cytokines contribute directly to their increased expression in muscle cells in vitro, while the role of IL-6 in the muscular induction of these APR was demonstrated in vivo. Conclusions Cancer is associated with marked changes in muscle secretome during muscle wasting. Our study demonstrates a marked increased production of APR by skeletal muscle in pre-clinical models of cancer cachexia and in cancer patients. Further studies are required to unravel the potential role of these proteins in muscle atrophy and their interest as biomarkers of cancer cachexia.
Project description:Cancer cachexia is a multifactorial condition characterized by skeletal muscle loss that impairs longevity and quality of life of the vast majority of cancer patients. However, the ability to develop therapeutic strategies to counter cachexia is impeded by the limited understanding of the underlying mechanisms of cachexia in human cancer patients. The purpose of this study was therefore to characterize the proteomic signature of skeletal muscle obtained from cachectic pancreatic ductal adenocarcinoma (PDAC) patients, who exhibit one of the highest rates of cachexia. Muscle biopsies (rectus abdominis) were obtained from PDAC patients (n=8; 70±10yr; BMI: 26.8±5.9kg・m-2) undergoing tumor resection surgery as well as age and sex-matched non-cancer controls (n=6; 66±9yr; BMI: 30.8±5.2kg・m-2). PDAC patients were cachectic (6 month body weight loss > 5%; mean: 15.7±7.9%) and did not undergo neoadjuvant therapy.
Project description:Background
Loss of skeletal muscle mass in cancer cachexia is recognized as an independent predictor of mortality. Mechanisms involved in this wasting process and parameters for early diagnosis are not yet clearly defined. As skeletal muscle is considered as a secretory organ, the aim of this present experimental work was to characterize the changes in the putative muscle secretome associated with cancer-induced cachexia to gain a better understanding of cellular mechanisms involved and to identify secreted proteins which might reflect this wasting process.
Methods
We investigated first the changes in the muscle proteome associated with cancer-induced cachexia by using differential label-free proteomic analysis on muscle of the C26 mouse model. The differentially abundant proteins were then submitted to sequential bioinformatic secretomic analysis in order to identify potentially secreted proteins. Multiple reaction monitoring and Western blotting were used to verify the presence of candidate proteins at the circulating level. Finally, we investigated the regulation of the production of these secreted proteins by muscle in vitro and in vivo.
Results
Our results revealed a dramatic increased muscular production (2-to 25-fold) of several acute phase reactants (APR: haptoglobin, serpina3n, complement C3, serum amyloid A1) which are released in the circulation during C26 cancer cachexia. This observation was confirmed in two other preclinical models of cancer cachexia as well as in cancer patients. The muscular origin of these APR was demonstrated by their increased expression in skeletal muscle and myotubes. Our results showed also that IL-6 plays a major role in the muscular induction of these APR in vivo, while glucocorticoids and pro-inflammatory cytokines stimulate directly their increased expression in muscle cells in vitro.
Conclusions
Muscle wasting caused by cancer is associated with marked changes in muscle secretome. Our study demonstrates a marked increased production of APR by skeletal muscle in pre-clinical models of cancer cachexia and in cancer patients. Further studies are required to unravel the potential role of these proteins in muscle atrophy and their interest as biomarkers of cancer cachexia.
Project description:Cancer cachexia, highly prevalent in lung cancer, is a debilitating syndrome characterized by involuntary loss of skeletal muscle mass, and is associated with poor clinical outcome, decreased survival and negative impact on on tumor therapy. Here we sought to identify the muscle gene profile and pathways regulated in cachexia. Vastus lateralis muscle was obtained of newly diagnosed treatment-naïve NSCLC patients with cachexia (n = 8) and matched healthy controls (n = 8). Self-reported weight loss and body composition measurements defined cachexia status. RNA sequencing was performed on the Illumina NovasSeq 6000.
Project description:The cancer anorexia cachexia syndrome is a systemic metabolic disorder characterized by the catabolism of stored nutrients in skeletal muscle and adipose tissue that is particularly prevalent in non-small cell lung cancer (NSCLC). Loss of skeletal muscle results in functional impairments and increased mortality. The aim of the current study was to characterize the changes in systemic metabolism in a genetically engineered mouse model of NSCLC. We show that a portion of these animals develop loss of skeletal muscle, loss of adipose tissue, and increased inflammatory markers mirroring the human cachexia syndrome. Using non-cachexic and fasted animals as controls, we report a unique cachexia metabolite phenotype that includes the dependent ketone production by the liver. In this setting, glucocorticoid levels rise and correlate with skeletal muscle degradation and hepatic markers of gluconeogenesis. Restoring prevents the loss of skeletal muscle mass and body weight. These results demonstrate how targeting hepatic metabolism can prevent muscle wasting in lung cancer, and provide evidence for a novel therapeutic strategy.
Project description:Cancer cachexia, highly prevalent in lung cancer, is a debilitating syndrome characterized by involuntary loss of skeletal muscle mass, and is associated with poor clinical outcome, decreased survival and negative impact on tumor therapy. Various lung tumor-bearing animal models have been used to explore underlying mechanisms of cancer cachexia. However, these models do not simulate anatomical and immunological features key to lung cancer and associated muscle wasting. Overcoming these shortcomings is essential to translate experimental findings into the clinic. We therefore evaluated whether a syngeneic, orthotopic lung cancer cachexia (OLCC) mouse model replicates systemic and muscle-specific alterations associated with human lung cancer cachexia. Immune competent, 11 weeks old male 129S2/Sv mice, were randomly allocated to either (1) sham control group or (2) tumor-bearing (OLCC) group. Syngeneic lung epithelium-derived adenocarcinoma cells (K-rasG12D; p53R172HΔG) were inoculated intrapulmonary into the left lung lobe of the mice. Body weight and food intake were measured daily. At baseline and weekly after surgery, grip strength was measured and tumor growth and muscle volume were assessed using micro cone beam CT imaging. After reaching predefined surrogate survival endpoint, animals were euthanized and skeletal muscles of the lower hind limbs were collected forRNA sequencing. RNA sequencing was performed on the Illumina NovasSeq 6000.
Project description:Cancer cachexia is a debilitating metabolic disorder characterized by involuntary loss of body and muscle mass, leading to increased morbidity and mortality. We previously found that Forkhead box P1 (FoxP1) upregulation in skeletal muscle causes muscle wasting and is required for muscle wasting in response to cancer. However, transcriptional networks targeted by FoxP1 in skeletal muscles undergoing cancer-induced wasting remain largely unknown. Here, we identify FoxP1 as a key disruptor of the skeletal muscle clock in response to cancer, that reprograms circadian patterns of gene expression at cachexia onset. Specifically, we show that cancer-induced FoxP1 rewires the skeletal muscle circadian transcriptome towards pathways associated with muscle wasting and disrupts the temporal patterning of pathways governing glucose, lipid, and oxidative metabolism. These findings thus implicate cancer/disease-specific functions of FOXP1 in the disruption and reprograming of the skeletal muscle circadian transcriptome which may contribute to muscle wasting and the development of cachexia.