Mouse Model Of Cancer Cachexia Research Articles

Dietary Naringenin Preserves Insulin Sensitivity and Grip Strength and Attenuates Inflammation but Accelerates Weight Loss in a Mouse Model of Cancer Cachexia.

Cancer cachexia is characterized by the loss of skeletal muscle resulting in functional impairment, reduced quality of life and mortality. Naringenin, a flavonoid found in citrus fruits, improves insulin sensitivity and reduces inflammation and tumor growth in preclinical models. Therefore, the study hypothesizes that dietary supplementation of naringenin will improve insulin sensitivity, decrease inflammation, slow body weight loss, and delay tumor growth in a mouse model of cancer cachexia. Mice are fed 2 wt% dietary naringenin before and during initiation of cancer cachexia using inoculated adenocarcinoma-26 cells (C-26). Food intake, body weight, body composition, muscle function, insulin tolerance, and inflammatory status are assessed. Although naringenin-fed tumor-bearing mice exhibit reductions in body weight and food intake earlier than control diet-fed tumor-bearing mice, dietary naringenin is protective against loss of muscle strength, and attenuates the onset of insulin resistance and markers of inflammation. Dietary supplementation of naringenin improves multiple aspects of metabolic disturbance and inflammation during cancer cachexia progression in [C-26 tumor-bearing] mice. However, the acceleration of anorexia and weight loss is also observed. These findings emphasize the link between inflammation and insulin resistance as a basis for understanding their roles in the pathogenesis of cancer cachexia.

Murine cancer cachexia models replicate elevated catabolic pembrolizumab clearance in humans.

BackgroundMonoclonal antibody (mAb) immune checkpoint inhibitor (ICI) therapies have dramatically impacted oncology this past decade. However, only about one‐third of patients respond to treatment, and biomarkers to predict responders are lacking. Recent ICI clinical pharmacology data demonstrate high baseline drug clearance (CL0) significantly associates with shorter overall survival, independent of ICI exposure, in patients receiving ICI mAb therapies. This suggests CL0 may predict outcomes from ICI therapy, and cachectic signalling may link elevated CL0 and poor response. Our aim was to determine if mouse models of cancer cachexia will be useful for studying these phenomena and their underlying mechanisms.MethodsWe evaluated pembrolizumab CL in the C26 and Lewis lung carcinoma mouse models of cancer cachexia. A single treatment of vehicle or pembrolizumab, at a dose of 2 or 10 mg/kg, was administered intravenously by tail vein injection. Pembrolizumab was quantified by an ELISA in serial plasma samples, and FcRn gene (Fcgrt) expression was assessed in liver using real‐time quantitative reverse transcription PCR. Non‐compartmental and mixed‐effects pharmacokinetics analyses were performed.ResultsWe observed higher pembrolizumab CL0 and decreased Fcgrt expression in whole liver tissue from tumour‐bearing vs. tumour‐free mice. In multivariate analysis, presence of tumour, total murine IgG, muscle weight and Fcgrt expression were significant covariates on CL, and total murine IgG was a significant covariate on V1 and Q.ConclusionsThese data demonstrate increases in catabolic clearance of monoclonal antibodies observed in humans can be replicated in cachectic mice, in which Fcgrt expression is also reduced. Notably, FcRn activity is essential for proper antigen presentation and antitumour immunity, which may permit the study of cachexia's impact on FcRn‐mediated clearance and efficacy of ICI therapies.

Skeletal muscle-specific over-expression of the nuclear sirtuin SIRT6 blocks cancer-associated cachexia by regulating multiple targets.

BackgroundDuring cancer cachexia, cytokines released from tumour cells can alter body's metabolism, which can lead to onset of this disease process. Biological basis of cachexia is multifactorial; hence, it is important to identify and modulate multiple targets to curtail the process of cachexia. Previously, we reported that the nuclear sirtuin, SIRT6, blocks expression of myostatin, a negative regulator of muscle growth, through modulation of the NF‐κB signalling. This study was undertaken to test whether muscle‐specific over‐expression of SIRT6 can block the cancer‐associated muscle wasting in vivo and to identify additional relevant targets of SIRT6, which can explain its ability to maintain muscle health.MethodsWe generated a skeletal muscle‐specific SIRT6 over‐expressing transgenic mouse line (Sk.T6Tg) expressing SIRT6 at a moderate (two‐fold to four‐fold) level, compared with its control littermates. To generate a cancer‐cachexia model, B16F10 mouse melanoma cells were injected subcutaneously in the flanks of mice. Gastrocnemius muscle tissues from non‐tumour and tumour controls and Sk.T6Tg mice (n = 5–20) were analysed by histology, immunoblotting, and RT‐qPCR. Plasma samples of mice were evaluated using cytokine arrays and ELISA in both non‐tumour and tumour conditions.ResultsOur results demonstrate dual benefits of muscle‐specific moderate over‐expression of SIRT6 in a mouse model of cancer‐cachexia. In tumour‐bearing mice, SIRT6 over‐expression preserved muscle weight (P < 0.001) and fibre size (P < 0.005) as well as suppressed tumour growth (P < 0.05). SIRT6 over‐expression significantly reduced myostatin expression and plasma free fatty acids levels but maintained plasma insulin levels in tumour‐bearing mice. These positive effects of SIRT6 were associated with downregulation of the circulatory chemokine, CXCL10, and the myokine, WNT4. SIRT6 also upregulated expression of GLUT4, the major glucose transporter in the skeletal muscle. These results for the first time demonstrate that SIRT6 regulates multiple targets to limit tumour growth and cancer‐associated muscle atrophy.ConclusionGiven the multifactorial nature of cachexia, SIRT6, which concurrently controls multiple pathways, can be a valuable therapeutic target to overcome this debilitating syndrome.

A standardized herbal combination of Astragalus membranaceus and Paeonia japonica, protects against muscle atrophy in a C26 colon cancer cachexia mouse model

Ethnopharmacological relevanceAstragalus membranaceus (Fisch.) and Bunge and Paeonia japonica (Makino)Miyabe & H.Takeda have been traditionally used to improve the poor quality of life such as weakness, lack of appetite, fatigue, and malaise which is considered with cachexia condition. Aim of the studyWe investigated anti-cachectic effects of a herbal formula composed of Astragalus membranaceus and Paeonia japonica (APX) and the molecular mechanisms of APX in C26 cancer-induced cachexia mice and TNF-a-treated C2C12 myotubes. Additionally synergistic anti-cachectic effects of APX were compared to those of individual herbal extracts and megestrol acetate. Methods and materialsThe forty-two BALB/c mice were randomly divided into 6 groups: normal (nontreatment), control (C26 injection), AM (C26 injection with Astragalus membranaceus), PJ (C26 injection with Paeonia japonica), APX (C26 injection with combination of Astragalus membranaceus and Paeonia japonica and MA (C26 injection with megestrol acetate). All mice were orally administered DW (normal and control groups) or 100 mg/kg AM, PJ, APX or MA for 10 days. In the animal model, several tissues were weighed, and muscle tissue and blood were used to measure pro-inflammatory cytokines. C2C12 myotubes were exposed to 100 ng/mL TNF- α with or without 10 μg/mL of AM, PJ, APX or MA for 48 h. The cells were used to immunofluorescence staining and western blot analyses. ResultsC26 injection induced notable body and muscle weight loss while APX administration significantly attenuated these alterations and the decrease of muscle weights and strength. APX also significantly attenuated the abnormal elevations in the concentration of three muscle atrophy-inducible cytokines; serum and muscle TNF-α,muscle TWEAK and IL-6 in C26 tumor-bearing mice. In the TNF-α-treated C2C12 myotube model, TNF-α treatment notably decreased MyH but activated atrophic proteins (MuRF and Fbx32) along with p38 and NFκB while these molecular alterations were significantly ameliorated by APX treatment. These pharmacological actions of APX were supported by the results of immunofluorescence staining to MyH expression and the translocation of NFκB into the nucleus in C2C12 myotubes. ConclusionsOur data indicate the potential of an herbal formula, APX as an anti-cachexia agent; the effect of APX was superior to that of megestrol acetate overall especially for muscle atrophy. The underlying mechanisms of this herbal formula may involve the modulation of muscle atrophy-promoting molecules including p38, NFκB, TNF-α and TWEAK.

Exercise training delays cardiac remodeling in a mouse model of cancer cachexia

AimsWe aimed to investigate the impact of cancer cachexia and previous aerobic exercise training (AET) on cardiac function and structure in tumor bearing mice. Main methodsColon adenocarcinoma cells 26 (CT26) were subcutaneously injected in BALB/c mice to establish robust cancer cachexia model. AET was performed on a treadmill during 45 days, 60 min/5 days per week. Cardiac function was evaluated by echocardiography and cardiac morphology was assessed by light microscopy. The protein expression levels of mitochondrial complex were analyzed by Western blotting. The mRNA levels of genes related to cardiac remodeling and autophagy were analyzed by quantitative Real-Time PCR. Key findingsOur data confirms CT26 tumor bearing mice as a well-characterized and robust model of cancer cachexia. CT26 mice exhibited cardiac remodeling and dysfunction characterized by cardiac atrophy and impaired left ventricle ejection fraction paralleled by cardiac necrosis, inflammation and fibrosis. AET partially reversed the left ventricle ejection fraction and led to significant anti-cardiac remodeling effect associated reduced necrosis, inflammation and cardiac collagen deposition in CT26 mice. Reduced TGF-β1 mRNA levels, increased mitochondrial complex IV protein levels and partial recovery of BNIP3 mRNA levels in cardiac tissue were associated with the cardiac effects of AET in CT26 mice. Thus, we suggest AET as a powerful regulator of key pathways involved in cardiac tissue homeostasis in cancer cachexia. SignificanceOur study provides a robust model of cancer cachexia, as well as highlights the potential and integrative effects of AET as a preventive strategy for reducing cardiac damage in cancer cachexia.

JNK signaling contributes to skeletal muscle wasting and protein turnover in pancreatic cancer cachexia.

Cancer cachexia patients experience significant muscle wasting, which impairs the quality of life and treatment efficacy for patients. Skeletal muscle protein turnover is imparted by increased expression of ubiquitin-proteasome pathway components. Mitogen-activated protein kinases p38 and ERK have been shown to augment E3 ubiquitin ligase expression. Utilizing reverse-phase protein arrays, we identified pancreatic cancer cell-conditioned media-induced activation of JNK signaling in myotubes differentiated from C2C12 myoblasts. Inhibition of JNK signaling with SP600125 reduced cancer cell-conditioned media-induced myotube atrophy, myosin heavy chain protein turnover, and mRNA expression of cachexia-specific ubiquitin ligases Trim63 and Fbxo32. Furthermore, utilizing an orthotopic pancreatic cancer cachexia mouse model, we demonstrated that treatment of tumor-bearing mice with SP600125 improved longitudinal measurements of forelimb grip strength. Post-necropsy measurements demonstrated that SP600125 treatment rescued body weight, carcass weight, and gastrocnemius muscle weight loss without impacting tumor growth. JNK inhibitor treatment also rescued myofiber degeneration and reduced the muscle expression of Trim63 and Fbxo32. These data demonstrate that JNK signaling contributes to muscle wasting in cancer cachexia, and its inhibition has the potential to be utilized as an anti-cachectic therapy.

Growth differentiation factor 15 (GDF-15) inhibition to increase muscle mass and function in cancer cachexia.

e15633 Background: Almost half of cancer deaths are attributed to cancers most frequently associated with cachexia. Cachexia is a complex metabolic disease characterized by anorexia and unintentional weight loss. Skeletal muscle depletion has been recognized as a key feature of the disease, however muscle anabolic therapies have not been successful, suggesting that treatments that target multiple aspects of the disease will be most effective. Growth differentiation factor 15 (GDF-15) is a cytokine that induces anorexia and weight loss and is associated with cachexia in cancer patients. In preclinical cancer cachexia models, GDF-15 inhibition is sufficient to normalize food intake and body weight, including skeletal muscle mass. However, it remains to be determined whether the increased skeletal muscle mass also results in restoration of muscle function. Therefore, we examined the effect of GDF-15 inhibition on muscle mass and function in mouse models of cancer cachexia in comparison with myostatin inhibition, an established muscle anabolic pathway. Methods: Cachectic mouse tumor models were established with subcutaneous implantation of tumor cell lines reported to be GDF-15-dependent; mouse renal cell carcinoma (RENCA) and human ovarian cancer (TOV-21G) cell lines. Mice were treated with anti-GDF-15 (mAB2) or anti-myostatin (RK35) monoclonal antibodies and skeletal muscle function was assessed in vivo via maximum force, maximum rate of contraction and half relax time. In the RENCA tumor model, GDF-15 inhibition fully restored body weight and skeletal muscle mass whereas myostatin inhibition showed only a modest effect. Results: Consistent with the muscle mass improvement, GDF-15 inhibition dramatically increased functional muscle endpoints compared to the partial effect of myostatin inhibition. Interestingly, in the TOV-21G tumor model GDF-15 inhibition only partially restored body weight, however skeletal muscle mass and muscle function were completely normalized. Consistent with the functional assessment, GDF-15 inhibition in the RENCA tumor model decreased the expression of several catabolic genes (i.e. Trim63, Fbxo32, Myh7 and Myh2). The GDF-15 effect is likely to be secondary to the reversal of anorexia since wildtype mice pair-fed to Fc-GDF-15-treated mice demonstrated equivalent muscle mass loss. Conclusions: Taken together these data suggest that GDF-15 inhibition holds potential as an effective therapeutic approach to alleviate multiple aspects of cachexia.

MEF2c-Dependent Downregulation of Myocilin Mediates Cancer-Induced Muscle Wasting and Associates with Cachexia in Patients with Cancer.

Skeletal muscle wasting is a devastating consequence of cancer that contributes to increased complications and poor survival, but is not well understood at the molecular level. Herein, we investigated the role of Myocilin (Myoc), a skeletal muscle hypertrophy-promoting protein that we showed is downregulated in multiple mouse models of cancer cachexia. Loss of Myoc alone was sufficient to induce phenotypes identified in mouse models of cancer cachexia, including muscle fiber atrophy, sarcolemmal fragility, and impaired muscle regeneration. By 18 months of age, mice deficient in Myoc showed significant skeletal muscle remodeling, characterized by increased fat and collagen deposition compared with wild-type mice, thus also supporting Myoc as a regulator of muscle quality. In cancer cachexia models, maintaining skeletal muscle expression of Myoc significantly attenuated muscle loss, while mice lacking Myoc showed enhanced muscle wasting. Furthermore, we identified the myocyte enhancer factor 2 C (MEF2C) transcription factor as a key upstream activator of Myoc whose gain of function significantly deterred cancer-induced muscle wasting and dysfunction in a preclinical model of pancreatic ductal adenocarcinoma (PDAC). Finally, compared with noncancer control patients, MYOC was significantly reduced in skeletal muscle of patients with PDAC defined as cachectic and correlated with MEF2c. These data therefore identify disruptions in MEF2c-dependent transcription of Myoc as a novel mechanism of cancer-associated muscle wasting that is similarly disrupted in muscle of patients with cachectic cancer. SIGNIFICANCE: This work identifies a novel transcriptional mechanism that mediates skeletal muscle wasting in murine models of cancer cachexia that is disrupted in skeletal muscle of patients with cancer exhibiting cachexia.

Ginsenoside Rb1 can ameliorate the key inflammatory cytokines TNF-\u03b1 and IL-6 in a cancer cachexia mouse model

BackgroundCancer cachexia is a severe condition that leads to the death of advanced cancer patients, and approximately 50~80% of cancer patients have cancer cachexia. Ginseng extract has been reported to have substantial anticancer and immune-enhancing effects; however, no study has reported the use of ginseng alone to treat cancer cachexia. Our study’s purpose was to investigate the therapeutic effects of ginseng-related monomers or mixtures on a cancer cachexia mouse model.MethodsWe selected BALB/c mice and injected the mice subcutaneously with C26 colon cancer cells to construct a cancer cachexia experimental animal model. The water extract of ginseng (WEG), two types of ginseng extracts (ginsenosides at doses of 5 mg/kg (GE5) and 50 mg/kg (GE50)) and ginsenoside Rb1 (Rb1) were used to treat cancer cachexia mice. Enzyme-linked immunosorbent assays (ELISAs) were used to analyze the inhibitory effects on two key inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).ResultsOur experimental results show that GE5, GE50 and Rb1 significantly reduced the levels of TNF-α (P < 0.01) and IL-6 (P < 0.01), which are closely related to cancer cachexia; however, WEG, GE5, GE50 and Rb1 did not significantly improve the gastrocnemius muscle weight or the epididymal fat weight of mice with cancer cachexia.ConclusionsThese results indicate that GE5, GE50 and Rb1 may be useful for reducing symptoms due to inflammation by reducing the TNF-α and IL-6 cytokine levels in cancer cachexia mice, thereby ameliorating the symptoms of cancer cachexia. Our results may be beneficial for future studies on the use of Chinese herbal medicines to treat cancer cachexia.

Overcoming resistance to anabolic SARM therapy in experimental cancer cachexia with an HDAC inhibitor

No approved therapy exists for cancer‐associated cachexia. The colon‐26 mouse model of cancer cachexia mimics recent late‐stage clinical failures of anabolic anti‐cachexia therapy and was unresponsive to anabolic doses of diverse androgens, including the selective androgen receptor modulator (SARM) GTx‐024. The histone deacetylase inhibitor (HDACi) AR‐42 exhibited anti‐cachectic activity in this model. We explored combined SARM/AR‐42 therapy as an improved anti‐cachectic treatment paradigm. A reduced dose of AR‐42 provided limited anti‐cachectic benefits, but, in combination with GTx‐024, significantly improved body weight, hindlimb muscle mass, and grip strength versus controls. AR‐42 suppressed the IL‐6/GP130/STAT3 signaling axis in muscle without impacting circulating cytokines. GTx‐024‐mediated β‐catenin target gene regulation was apparent in cachectic mice only when combined with AR‐42. Our data suggest cachectic signaling in this model involves catabolic signaling insensitive to anabolic GTx‐024 therapy and a blockade of GTx‐024‐mediated anabolic signaling. AR‐42 mitigates catabolic gene activation and restores anabolic responsiveness to GTx‐024. Combining GTx‐024, a clinically established anabolic therapy, with AR‐42, a clinically evaluated HDACi, represents a promising approach to improve anabolic response in cachectic patients.

Paeonia lactiflora root extract suppresses cancer cachexia by down-regulating muscular NF-κB signalling and muscle-specific E3 ubiquitin ligases in cancer-bearing mice.

The dried root of Paeonia lactiflora Pall. (Radix Paeoniae) has been traditionally used to treat various inflammatory diseases in many Asian countries. Cancer cachexia is a catabolic syndrome driven by inflammation and characterised by a loss of skeletal muscle. This study aimed to assess the effects of an ethanolic extract of Radix Paeoniae (RP) on cancer cachexia and elucidate its mechanism of action. The anti-cachexic effect and mechanism of RP were examined in mouse models of cancer cachexia established in C57BL/6 mice by subcutaneously injecting Lewis lung carcinoma or MC38 colon carcinoma cells. Skeletal muscle tissues were analysed by RNAseq, real-time quantitative reverse transcription PCR, western blotting, and immunofluorescence microscopy. Megestrol acetate, which is recommended for the treatment of cachexia in cancer patients, was used as the comparator treatment in this study. In lung and colon cancer-bearing mice, RP significantly restored food intake and muscle mass, along with muscle function measured by grip strength and treadmill running time. In the skeletal muscle tissue of the cancer-bearing mice, RP suppressed NF-κB signalling and reduced inflammatory cytokines, including TNF-α, IL-6, and IL-1β; it also down-regulated the muscle-specific E3 ubiquitin ligases MuRF1 and MAFbx. RP restored skeletal muscle function and mass in cancer-bearing mice by down-regulating the muscular NF-κB signalling pathway and muscle-specific E3 ubiquitin ligases. Our study indicates that RP is a potential candidate for development as a therapeutic agent against cancer cachexia.

Establishment of a mouse model of cancer cachexia with spleen deficiency syndrome and the effects of atractylenolide I.

Cancer cachexia is a multifactorial metabolic syndrome that affects ∼50%–80% of cancer patients, and no effective therapy for cancer cachexia is presently available. In traditional Chinese medicine, a large portion of patients with cancer cachexia was diagnosed as spleen deficiency syndrome and treated with tonifying TCMs that produce clinic benefits. In this study we established a new animal model of spleen deficiency and cancer cachexia in mice and evaluated the therapeutic effects of atractylenolide I, an active component of tonifying TCM BaiZhu, in the mouse model. Cancer cachexia was induced in male BALB/c mice by inoculation of mouse C26 colon adenocarcinoma cells, whereas spleen deficiency syndrome was induced by treating the mice with spleen deficiency-inducing factors, including limited feeding, fatigue, and purging. The mouse model was characterized by both cachexia and spleen deficiency characteristics, including significant body weight loss, cancer growth, muscle atrophy, fat lipolysis, spleen, and thymus atrophy as compared with healthy control mice, cancer cachexia mice, and spleen deficiency mice. Oral administration of atractylenolide I (20 mg· kg−1per day, for 30 days) significantly ameliorated the reduction in body weight and atrophy of muscle, fat, spleen, and thymus in mice with spleen deficiency and cachexia. The established model of spleen deficiency and cancer cachexia might be useful in the future for screening possible anticachexia TCMs and clarifying their mechanisms.

Potential role of immunological factors in early diagnosis of cancer cachexia in C26 tumor-bearing mice

Cachexia is a wasting syndrome associated with high mortality in cancer patients through inducing the failure of normal metabolism and reducing the efficacy of cancer treatment. Thus, it is critically important to diagnose cancer cachexia early. To provide background data for the diagnosis of cachexia, cancer cachectic factors were characterized in the present situation, including immunological cachectic changes during cachexia progression in a cancer cachexia mouse model. Major constitution of cachexia progression is known as the stages of pre-cachexia, cachexia, and refractory cachexia. In the pre-cachexia stage, the weights of immune-related organs, including the thymus and spleen were significantly. T cell populations in spleen were markedly reduced and cachectic cytokines consistently increased in a time-dependent manner. Immunosuppression by activation of cytotoxic T-lymphocyte-associated antigen 4 was induced earlier in CD4+ cells versus other T cell populations. Furthermore, monocyte chemoattractant protein 1 and interleukin-6 levels in the cachexia group were significantly increased at 3 days from C26 cell inoculation whereas significant carcass weight loss as a classical diagnostic marker occurred at 9 days from C26 cell inoculation. In conclusion, the initiation of cachectic immunological changes was observed prior to weight loss, during the pre-cachexia stage. Accordingly, these findings reveal that the monitoring of humoral and immunological factors may be more sensitive than weight loss for the initial diagnosis and treatment of cachexia.

PERK regulates skeletal muscle mass and contractile function in adult mice.

Skeletal muscle mass is regulated by the coordinated activation of several anabolic and catabolic pathways. The endoplasmic reticulum (ER) is a major site of protein folding and a reservoir for calcium ions. Accretion of misfolded proteins or depletion in calcium concentration causes stress in the ER, which leads to the activation of a signaling network known as the unfolded protein response (UPR). In the present study, we investigated the role of the protein kinase R-like endoplasmic reticulum kinase (PERK) arm of the UPR in the regulation of skeletal muscle mass and function in naive conditions and in a mouse model of cancer cachexia. Our results demonstrate that the targeted inducible deletion of PERK reduces skeletal muscle mass, strength, and force production during isometric contractions. Deletion of PERK also causes a slow-to-fast fiber type transition in skeletal muscle. Furthermore, short hairpin RNA-mediated knockdown or pharmacologic inhibition of PERK leads to atrophy in cultured myotubes. While increasing the rate of protein synthesis, the targeted deletion of PERK leads to the increased expression of components of the ubiquitin-proteasome system and autophagy in skeletal muscle. Ablation of PERK also increases the activation of calpains and deregulates the gene expression of the members of the FGF19 subfamily. Furthermore, the targeted deletion of PERK increases muscle wasting in Lewis lung carcinoma tumor-bearing mice. Our findings suggest that the PERK arm of the UPR is essential for the maintenance of skeletal muscle mass and function in adult mice.-Gallot, Y. S., Bohnert, K. R., Straughn, A. R., Xiong, G., Hindi, S. M., Kumar, A. PERK regulates skeletal muscle mass and contractile function in adult mice.

Increased gut permeability in cancer cachexia: mechanisms and clinical relevance.

Intestinal disorders often occur in cancer patients, in association with body weight loss, and this alteration is commonly attributed to the chemotherapy. Here, using a mouse model of cancer cachexia induced by ectopic transplantation of C26 cancer cells, we discovered a profound alteration in the gut functions (gut permeability, epithelial turnover, gut immunity, microbial dysbiosis) independently of any chemotherapy. These alterations occurred independently of anorexia and were driven by interleukin 6. Gut dysfunction was found to be resistant to treatments with an anti-inflammatory bacterium (Faecalibacterium prausnitzii) or with gut peptides involved in intestinal cell renewal (teduglutide, a glucagon-like peptide 2 analogue). The translational value of our findings was evaluated in 152 colorectal and lung cancer patients with or without cachexia. The serum level of the lipopolysaccharide-binding protein, often presented as a reflection of the bacterial antigen load, was not only increased in cachectic mice and cancer patients, but also strongly correlated with the serum IL-6 level and predictive of death and cachexia occurrence in these patients. Altogether, our data highlight profound alterations of the intestinal homeostasis in cancer cachexia occurring independently of any chemotherapy and food intake reduction, with potential relevance in humans. In addition, we point out the lipopolysaccharide-binding protein as a new biomarker of cancer cachexia related to gut dysbiosis.

Bone mineral density and content are differentially impacted by aerobic and resistance training in the colon-26 mouse model of cancer cachexia

BackgroundCancer cachexia is a debilitating paraneoplastic syndrome featuring unintended weight loss and skeletal muscle atrophy. Evidence suggests that bone health may also be compromised, further limiting mobility and quality of life. Aerobic and resistance training was recently reported to differentially affect skeletal muscle adaptations in cancer cachectic mice. The purpose of this investigation was to assess the effects of aerobic and resistance training on bone mineral density (BMD) and bone mineral content (BMC) in mice with colon-26 (C26) tumor-induced cachexia.MethodsTwelve-month old Balb/c mice were aerobic-trained (wheel running 5 days/week) or resistance-trained (weighted ladder climbing 3days/week) for 8 weeks prior to C26 cell injection, followed by an additional three weeks of exercise. BMD and BMC were assessed pre- and post-training by dual-energy x-ray absorptiometry.ResultsResistance-trained C26 mice lost total BMD by 7% (p = 0.06), which did not occur in aerobic-trained C26 mice. In terms of pelvic bone, both resistance- and aerobic-trained C26 mice had significantly lower BMD values (−12%, p = 0.01 and −6%, p = 0.04, respectively), albeit to a lesser degree in aerobic-trained C26 mice. Furthermore, resistance-trained C26 mice tended to lose total BMC (−12%), whereas aerobic-trained C26 mice maintained total BMC. In mice without C26 tumors, resistance training significantly increased total BMD (+13%, p = 0.001).ConclusionsAerobic and resistance training may differentially affect bone status in C26 cancer cachexia, with high resistance loading possibly being detrimental to total and pelvis BMD, a region expected to bear significant loading stress and contribute substantially to overall mobility. Because resistance training improved BMD in tumor-free mice, the C26 tumor burden appeared to impair the beneficial effect of resistance training on bone mass.

Z-505 hydrochloride, an orally active ghrelin agonist, attenuates the progression of cancer cachexia via anabolic hormones in Colon 26 tumor-bearing mice

Cancer cachexia is a progressive wasting syndrome characterized by anorexia and weight loss, specifically muscle wasting and fat depletion. There is no therapeutic agent for treatment of this syndrome. We investigated the anti-cachexia effects of Z-505 hydrochloride (Z-505), a new oral growth hormone secretagogue receptor 1a (GHSR1a) agonist, using a mouse model of cancer cachexia. We performed a calcium flux assay in Chinese hamster ovary (CHO-K1) cells stably expressing human GHSR1a to quantify the agonistic activity of Z-505. In Colon 26 tumor-bearing mice, Z-505 (300mg/kg, p.o., twice daily) was administered for 7 days to assess its anti-cachexia effects. Body weight and food intake were monitored during the period, and the skeletal muscle and epididymal fat weights were measured. Serum levels of insulin, insulin-like growth factor 1 (IGF-1), interleukin-6 (IL-6), and corticosterone were measured to confirm the mechanism of the anti-cachexia action of Z-505. Z-505 showed strong agonistic activity similar to that of human ghrelin, with a half maximal effective concentration (EC50) value of 0.45nM. Z-505 treatment significantly increased food intake and inhibited the progression of weight loss. Z-505 also significantly attenuated muscle wasting and fat loss, and increased circulating levels of anabolic factors such as insulin and IGF-1, but not catabolic factors such as IL-6 and corticosterone. These findings suggest that Z-505 might be effective in the treatment of cachexia via the increased anabolic hormone levels stimulated by the activation of the ghrelin receptor, GHSR1a.

Increased thrombin generation in a mouse model of cancer cachexia is partially interleukin‐6 dependent

Background Cancer cachexia and cancer-associated thrombosis are potentially fatal outcomes of advanced cancer, which have not previously been mechanistically linked. The colon 26 (C26) carcinoma is a well-established mouse model of complications of advanced cancer cachexia, partially dependent on high levels of interleukin-6 (IL-6) produced by the tumor. Objectives To assess if cancer cachexia altered the coagulation state and if this was attributable to tumor IL-6 production. Methods In male BALB/c*DBA2 (F1 hybrid) mice with a C26 tumor we used modified calibrated automated thrombogram and fibrin generation (based on overall hemostatic potential) assays to assess the functional coagulation state, and also examined fibrinogen, erythrocyte sedimentation rate (ESR), platelet count, tissue factor pathway inhibitor (TFPI) and hepatic expression of coagulation factors by microarray. C26 mice were compared with non-cachectic NC26, pair-fed and sham control mice. IL-6 expression in C26 cells was knocked down by lentiviral shRNA constructs. Results C26 mice with significant weight loss and highly elevated IL-6 had elevated thrombin generation, fibrinogen, ESR, platelets and TFPI compared with all control groups. Fibrin generation was elevated compared with pair-fed and sham controls but not compared with NC26 tumor mice. Hepatic expression of coagulation factors and fibrinolytic inhibitors was increased. Silencing IL-6 in the tumor significantly, but incompletely, attenuated the increased thrombin generation, fibrinogen and TFPI. Conclusions Cachectic C26 tumor-bearing mice are in a hypercoagulable state, which is partly attributable to IL-6 release by the tumor. The findings support the importance of the coagulation state in cancer cachexia and the clinical utility of anti-inflammatory interventions.

Cancer cachexia-when proteasomal inhibition is not enough.

Cachexia is a life threatening syndrome associated with several diseases, such as end‐stage heart failure, end‐stage renal disease, chronic obstructive pulmonary disease, chronic inflammation (i.e. rheumatoid arthritis), acquired immune deficiency syndrome, and cancer.1, 2 Cachexia is found in 31–87% of cancer patients especially in advanced disease stages.3 It is characterized by progressive weight loss, metabolic alterations, fatigue, and persistent reduction of body cell mass in response to a malignant tumour.2, 4, 5, 6 The incidence of cachexia in cancer patients is dependent on the type and site of the tumour. While patients with non‐Hodgkin's lymphoma, breast cancer, and sarcomas show low incidences, rates up to 83% in pancreatic cancer patients, and over 85% in patients with gastric cancer have been found. Additionally, around 60% of small‐cell and non‐small‐cell lung cancer patients develop cachexia.7, 8, 9 Cancer cachexia affects the function of several organs such as muscle, adipose tissue, liver, brain, immune system, and heart, collectively decreasing patients' quality of life and worsening their prognosis. Therefore, cachexia must be considered as a true multi‐organ syndrome.10 Because cancer cachexia leads to a decrease in physical performance and quality of life,11 and is associated with poor survival (accounting for more than 20% of cancer deaths,7, 12, 13, 14, 15) it is of major clinical relevance. Even more so since cachectic patients show lower response rates to chemotherapy7 and a reduced tolerance to anticancer treatment.16 Despite its importance, weight loss in cancer patients is rarely recognized, assessed,17 or treated actively.18, 19 Thus, cancer cachexia represents an important underappreciated clinical syndrome.

Inhibition of ER stress and unfolding protein response pathways causes skeletal muscle wasting during cancer cachexia.

Cachexia is a devastating syndrome that causes morbidity and mortality in a large number of patients with cancer. However, the mechanisms of cancer cachexia remain poorly understood. Accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes stress. The ER responds to this stress through activating certain pathways commonly known as the unfolding protein response (UPR). The main function of UPR is to restore homeostasis, but excessive or prolonged activation of UPR can lead to pathologic conditions. In this study, we examined the role of ER stress and UPR in regulation of skeletal muscle mass in naïve conditions and during cancer cachexia. Our results demonstrate that multiple markers of ER stress are highly activated in skeletal muscle of Lewis lung carcinoma (LLC) and Apc(Min/+) mouse models of cancer cachexia. Treatment of mice with 4-phenylbutyrate (4-PBA), a chemical chaperon and a potent inhibitor of ER stress, significantly reduced skeletal muscle strength and mass in both control and LLC-bearing mice. Blocking the UPR also increased the proportion of fast-type fibers in soleus muscle of both control and LLC-bearing mice. Inhibition of UPR reduced the activity of Akt/mTOR pathway and increased the expression of the components of the ubiquitin-proteasome system and autophagy in LLC-bearing mice. Moreover, we found that the inhibition of UPR causes severe atrophy in cultured myotubes. Our study provides initial evidence that ER stress and UPR pathways are essential for maintaining skeletal muscle mass and strength and for protection against cancer cachexia.-Bohnert, K. R., Gallot, Y. S., Sato, S., Xiong, G., Hindi, S. M., Kumar, A. Inhibition of ER stress and unfolding protein response pathways causes skeletal muscle wasting during cancer cachexia.