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: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 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: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, 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: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 and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer-related muscle wasting and its mechanism using a colon-26 murine cachexia model. Compared to a fiber-free (FF) diet, PHGG contained fiber-rich (FR) diet attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle-specific ubiquitin ligases Atrogin-1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight junction markers were partially reduced in both FR and FF diet-fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24-7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide-binding protein (LBP) and IL-6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin-proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.
Project description:Advanced colorectal cancer (CRC), a leading cause of death worldwide, is often accompanied by the development of liver metastases (LM), as well as skeletal muscle (SkM) wasting, i.e. cachexia. Despite affecting the majority of CRC patients, cachexia remains understudied and uncured. Moreover, only a single model of LM associated with CRC has been developed for the study of cachexia. Here we examined differential gene expression of skeletal muscles deriving from subcutaneous and metastatic C26 tumor hosts. Tumor hosts displaying LM experienced exacerbated muscle wasting compared to tumor hosts without LM.
Project description:Pancreatic cancer is characterized by a high frequency of cachexia, pain and neural invasion (N-inv). Neural damage is occurred by N-inv and modulates pain and muscle atrophy via the activation of astrocyte in the connected spine. The activated astrocyte by N-inv, thus, may affect cachexia in pancreatic cancer. Clinical studies in patients and autopsy cases with pancreatic cancer have revealed that N-inv is related to cachexia and astrocytic activation. We established a novel murine model of cancer cachexia using N-inv of human pancreatic cancer cells. Mice with N-inv showed a loss of body weight, skeletal muscle, and fat mass without appetite loss, which are compatible with an animal model of cancer cachexia. Activation of astrocytes in the spinal cord connected with N-inv was observed in our model. Experimental cachexia was suppressed by disrupting neural routes or inhibiting the activation of astrocytes. These data provide the first evidence that N-inv induces cachexia via astrocytic activation of neural route in pancreatic cancer. We produced neural invasion (N-inv) model using intraneural injection of Capan-1 cells to left sciatic nerve of male SCID mouse. For controls, subcutaneous model (SC) and PBS model were produced. Microarray analysis was performed using the first lumbar cord (L1) from PBS, SC, and N-inv mice at 6 w (n = 2 each).
Project description:Background. Pancreatic Ductal AdenoCarcinoma (PDAC), the most frequent pancreatic cancer, is a deadly cancer since often diagnosed late and resistant to current therapies. A high proportion of PDAC patients are affected by cachexia induced by the tumor. This cachexia, characterized by loss of muscle mass and strength, contributes to patient frailty and poor therapeutic response. We showed that mitochondrial metabolism is reprogrammed in PDAC tumor cell and constitutes a vulnerability, opening novel therapeutic avenues. The objective of the present work was to investigate the molecular mechanisms underlying mitochondrial remodeling in PDAC cachectic skeletal muscle. Methods. Our study focused on the gastrocnemius muscle of genetically-engineered mice developing spontaneously a PDAC associated with cachexia (KIC GEMM). We compared KIC mice developing a pancreatic tumor in 9-10 weeks to control littermates. We did an integrative study combining in vivo functional analyses by non-invasive Magnetic Resonance, and ex-vivo histology, Seahorse, RNA-sequencing, and proteomic mass spectrometry and western blotting analyses. Results. The cachectic KIC PDAC mice show a severe sarcopenia with loss of muscle mass and strength associated with a diminution in muscle fiber’s size and induction of protein degradation processes. Mitochondria in PDAC atrophic muscles show decreased respiratory capacities and structural alterations (“hyperfused” mitochondria), associated with deregulation of oxidative phosphorylation and mitochondrial dynamics pathways at the molecular level. Increased expression of multiple reactive oxygen species (ROS) defense genes suggests oxidative stress prone to affect mitochondrial macromolecules and homeostasis. Interestingly, multiple genes and proteins involved in DNA metabolism pathways, such as DNA damage, degradation of DNA, nucleotide synthesis, and folate pathway were found altered in sarcopenic mitochondria. While the number of mitochondria was not changed, the mitochondrial mass was decreased by a factor of 2 and the mitochondrial DNA by a factor of 3, suggesting a defect in mitochondrial genome homeostasis. Conclusions. We unveiled that mitochondrial alterations in skeletal muscle play a central role in PDAC-induced cachexia. Muscle atrophy is associated with strong mitochondrial metabolic defects that are not limited to carbohydrates and protein, but concern also lipids, ROS and nucleic acids. Our data provide a frame to guide towards the most relevant molecular markers that would be affected at the start of tumor development and could be targets in the clinic to limit PDAC-induced cachexia at early stages of the pathology.