Mouse Model Of Cancer Cachexia Research Articles

Effects of Dietary Linoleic Acid on Mitochondrial Function in Skeletal Muscles Isolated From a Mouse Model of Cancer Cachexia

Effects of Dietary Linoleic Acid on Mitochondrial Function in Skeletal Muscles Isolated From a Mouse Model of Cancer Cachexia

Peripheral-central network analysis of cancer cachexia status accompanied by the polarization of hypothalamic microglia with low expression of inhibitory immune checkpoint receptors

While the excessive inflammation in cancer cachexia is well-known to be induced by the overproduction of inflammatory mediators in the periphery, microflora disruption and brain dysfunction are also considered to contribute to the induction of cancer cachexia. Hypothalamic microglia play a crucial role in brain inflammation and central-peripheral immune circuits via the production of inflammatory mediators. In the present study, we evaluated possible changes in excessive secretion of gut microbiota-derived endotoxin and the expression timeline of several inflammation-regulatory mediators and their inhibiting modulators in hypothalamic microglia of a mouse model of cancer cachexia following transplantation of pancreatic cancer cells. We demonstrated that the plasma level of lipopolysaccharide (LPS) was significantly increased with an increase in anaerobic bacteria, especially Firmicutes, in the gut at the late stage of tumor-bearing mice that exhibited dramatic appetite loss, sarcopenia and severe peripheral immune suppression. At the early stage, in which tumor-bearing mice had not yet displayed “cachexia symptoms”, the mRNA expression of pro-inflammatory cytokines, but not of the neurodegenerative and severe inflammatory modulator lipocalin-2 (LCN2), was significantly increased, whereas at the late “cachexia stage”, the level of LCN2 mRNA was significantly increased along with significant decreases in levels of inhibitory immune checkpoint receptors programmed death receptor-1 (PD-1) and CD112R in hypothalamic microglia. In addition, a high density of activated neurons in the paraventricular nucleus (PVN) of the hypothalamus region and a significant increase in corticosterone secretion were found in cachexia model mice. Related to the cachexia state, released corticosterone was clearly increased in normal mice with specific activation of PVN neurons. A marked decrease in the natural killer cell population was also observed in the spleen of mice with robust activation of PVN neurons as well as mice with cancer cachexia. On the other hand, in vivo administration of LPS in normal mice induced hypothalamic microglia with low expression of inhibitory immune checkpoint receptors. These findings suggest that the induction of cancer cachexia may parallel exacerbation of the hypothalamic inflammatory status with polarization to microglia expressed with low levels of inhibitory immune checkpoint receptors following LPS release from the gut microflora.

Abstract 4457: Skeletal muscle-infiltrating CD8 T cells exacerbate muscle atrophy in a syngeneic lung cancer cachexia mouse model

Abstract Cancer-associated cachexia (CAC) is a devastating syndrome of irreversible body weight loss and muscle wasting. CAC has been reported to often lead to poor outcomes of immune checkpoint inhibitors (ICIs), emerging as a standard treatment for various types of cancer. Previously, we have demonstrated that KRAS-mutant lung tumor tissues display an immunosuppressive microenvironment with decreased CD8 T cells and increased regulatory T cells (Tregs). In this orthotopic lung cancer mouse model, treatment with an anti-PD-L1 antibody, a representative ICI, reduced tumor burden, whereas accelerated loss of body weight and skeletal muscle mass. We thus assumed that CD8 T cells could facilitate skeletal muscle wasting in lung tumor-bearing mice, a key feature of CAC. First, we established a syngeneic CAC mouse model through orthotopic transplantation of murine lung cancer cells. At 7 weeks post-injection, these mice developed CAC, displaying over 20 % body weight loss, almost total loss of epididymal fats, and profound skeletal muscle wasting. In line with our assumption, CAC mice showed an increased number of CD8 T cells but a reduced number of Tregs in skeletal muscles, compared to tumor-free control mice. We then investigated whether skeletal muscle-infiltrating CD8 T cells directly induce muscle atrophy indeed. In CAC mice, CD8 neutralization led to restoration of muscle mass and downregulation of muscle atrophy markers, but was not able to significantly affect lung tumor burden. Moreover, direct co-culture with splenic CD8 T cells exacerbated C2C12 myotube atrophy in a conditioned medium from lung cancer cells, further supporting the involvement of CD8 T cells in CAC. To elucidate its underlying mechanism, RNA sequencing analysis was conducted in both skeletal muscles and lung tumors of CAC mice. Based on the differently expressed gene analysis, Cxcl13 was upregulated in skeletal muscles of CAC mice, while downregulated in lung tumors. It is well documented that CXCL13 can mediate recruitment of CD8 T cells. In this regard, CXCL13 might be a plausible regulator in CD8 T cell-induced skeletal muscle atrophy, which requires further investigation to fully understand the molecular mechanism. Citation Format: Se-Young Park, Bomi Kim, Myunggyo Lee, Haeseung Lee, Na-Young Song. Skeletal muscle-infiltrating CD8 T cells exacerbate muscle atrophy in a syngeneic lung cancer cachexia mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4457.

β‑carotene attenuates muscle wasting in cancer cachexia by regulating myogenesis and muscle atrophy.

Cancer cachexia is a metabolic disease involving multiple organs, which is accompanied by the depletion of muscle tissue and is associated with ~20% of cancer‑related deaths. Muscle wasting is a critical factor in cancer cachexia. β‑carotene (BC) has been shown to increase muscle mass and hypertrophy in healthy mice. However, its effects on muscle tissue dysregulation in cancer cachexia have yet to be studied. In the present study, 5‑week‑old male C57BL/6J mice were injected with 1x106 Lewis lung carcinoma (LLC) cells to induce cancer cachexia; then the mice were administered BC (4or8mg/kg) for 22days to assess its effects on muscle atrophy in the gastrocnemius muscles. The effects of BC on inflammatory cytokines, myogenesis and muscle atrophy were evaluated using C2C12 myotubes treated with LLC‑conditioned media. BC supplementation significantly suppressed tumor growth, inflammatory cytokines, and hepatic gluconeogenesis in the LLC‑induced cancer cachexia mouse model, while also improving muscle weight and grip strength. These effects are considered to be mediated by the PI3K/Akt pathway and through regulation of muscle atrophy. Moreover, BC treatment was associated with the recovery of LLC‑conditioned media‑induced muscle differentiation deficits and muscle atrophy in C2C12 myotubes. These findings indicate BC as a potential novel therapeutic agent for cancer cachexia.

Exosomal EIF5A derived from Lewis lung carcinoma induced adipocyte wasting in cancer cachexia

Cancer cachexia is a systemic inflammation-driven syndrome, characterized by muscle atrophy and adipose tissue wasting, with progressive weight loss leading to serious impairment of physiological function. Extracellular vesicles (EVs) derived from cancer cells play a significant role in adipocyte lipolysis, yet the mechanism remain uneclucidated. In this study, EVs derived from Lewis lung carcinoma (LLC) cells were extracted and characterized. 3T3-L1 and HIB1B adipocytes were cultured with conditioned medium or EVs from LLC, and LLC cells were used to establish a cancer cachexia mouse model. EVs derived from LLC cells were taken up by 3T3-L1 and HIB1B adipocytes, and derived exosomal EIF5A protein-induced lipolysis of adipocytes. High level of EIF5A was expressed in EVs from LLC cells, exosomal EIF5A is linked to lipid metabolism. Elevated expression of EIF5A is associated with shorter overall survival in lung cancer patients. Western blots, glycerol release and Oil red O staining assays were used to evaluate lipolysis of adipocytes. The reduction of lipolysis in 3T3-L1 and HIB1B adipocytes is achieved through silencing EIF5A or treating with pharmacologic inhibitor GC7 in vitro, and suppressing the expression of EIF5A in LLC cells by infected with shRNA or GC7 treatment partly alleviated white and brown adipose tissue lipolysis in vivo. Mechanistically, EIF5A directly binds with G protein-coupled bile acid receptor 1 (GPBAR1) mRNA to promote its translation and then activates cAMP response element binding protein (CREB) signaling pathway to induce lipolysis. This study demonstrates that exosomal EIF5A from LLC cells, with hypusinated EIF5A, has a lipolytic effect on adipocyte and adipose tissues in cancer cachexia model. Exosomal EIF5A could be involved in lipolysis and these findings indicate that a novel regulator and potential target for cachexia treatment.

Unraveling the gut microbiota and short-chain fatty acids characteristics and associations in a cancer cachexia mouse model

ObjectiveCachexia is a common pathological condition in cancer patients, affecting prognosis and treatment outcomes. The relationship between cachexia and gut microbiota and short-chain fatty acids (SCFAs) remains understudied. This research aimed to establish a cachexia mouse model and explore the gut microbiota-SCFAs connection. The study provides fundamental insights into the regulatory mechanisms of cancer cachexia and potential therapeutic strategies. MethodsA cachexia mouse model was created using C26 cells, with relevant indicators measured. Histological and immunohistochemical analyses assessed muscle structure and protein expression. ELISA was performed to detect the levels of IL-1β, IL-6, TNF-α, and LPS in serum to evaluate inflammation.16S rDNA sequencing and GC-MS quantified gut microbiota and SCFAs. Bioinformatics analysis identified indicator species and explored microbiota-SCFAs correlations.ROC analysis was performed to assess the potential of gut microbiota and SCFAs in identifying cachexia. ResultsThe cachexia mouse model exhibited weight loss, muscle atrophy, and elevated inflammatory factors. Gut microbiota in cachexia mice showed decreased diversity and imbalance. Fourteen bacterial genera were identified as potential cachexia indicators. Functional prediction indicated alterations in the functional composition of gut microbial communities in cachexia mice, particularly in carbohydrate and lipid metabolism pathways. Four SCFAs showed significant changes, potentially serving as diagnostic factors. Specific microbial taxa were positively or negatively correlated with changes in SCFAs, and these microbial taxa and differential SCFAs were also correlated with inflammatory cytokines. ConclusionOur study uncovers the gut microbiota and SCFAs features in a cachexia mouse model, revealing novel correlations between them. These newfound insights into the interplay between cachexia, gut microbiota, and SCFAs provide a crucial foundation for understanding the mechanisms behind cancer cachexia development and potential therapeutic approaches.

Metabolic signatures and potential biomarkers for the diagnosis and treatment of colon cancer cachexia.

Cancer cachexia (CAC) is a debilitating condition that often arises from noncachexia cancer (NCAC), with distinct metabolic characteristics and medical treatments. However, the metabolic changes and underlying molecular mechanisms during cachexia progression remain poorly understood. Understanding the progression of CAC is crucial for developing diagnostic approaches to distinguish between CAC and NCAC stages, facilitating appropriate treatment for cancer patients. In this study, we establish a mouse model of colon CAC and categorize the mice into three groups: CAC, NCAC and normal control (NOR). By performing nuclear magnetic resonance (NMR)-based metabolomic profiling on mouse sera, we elucidate the metabolic properties of these groups. Our findings unveil significant differences in the metabolic profiles among the CAC, NCAC and NOR groups, highlighting significant impairments in energy metabolism and amino acid metabolism during cachexia progression. Additionally, we observe the elevated serum levels of lysine and acetate during the transition from the NCAC to CAC stages. Using multivariate ROC analysis, we identify lysine and acetate as potential biomarkers for distinguishing between CAC and NCAC stages. These biomarkers hold promise for the diagnosis of CAC from noncachexia cancer. Our study provides novel insights into the metabolic mechanisms underlying cachexia progression and offers valuable avenues for the diagnosis and treatment of CAC in clinical settings.

P22-004-23 Effects of Dietary Linoleic Acid on Insulin Resistance and Loss of Adipose Tissue and Skeletal Muscle in a Mouse Model of Cancer Cachexia

P22-004-23 Effects of Dietary Linoleic Acid on Insulin Resistance and Loss of Adipose Tissue and Skeletal Muscle in a Mouse Model of Cancer Cachexia

Impairment of aryl hydrocarbon receptor signalling promotes hepatic disorders in cancer cachexia.

The aryl hydrocarbon receptor (AHR) is expressed in the intestine and liver, where it has pleiotropic functions and target genes. This study aims to explore the potential implication of AHR in cancer cachexia, an inflammatory and metabolic syndrome contributing to cancer death. Specifically, we tested the hypothesis that targeting AHR can alleviate cachectic features, particularly through the gut-liver axis. AHR pathways were explored in multiple tissues from four experimental mouse models of cancer cachexia (C26, BaF3, MC38 and APCMin/+ ) and from non-cachectic mice (sham-injected mice and non-cachexia-inducing [NC26] tumour-bearing mice), as well as in liver biopsies from cancer patients. Cachectic mice were treated with an AHR agonist (6-formylindolo(3,2-b)carbazole [FICZ]) or an antibody neutralizing interleukin-6 (IL-6). Key mechanisms were validated in vitro on HepG2 cells. AHR activation, reflected by the expression of Cyp1a1 and Cyp1a2, two major AHR target genes, was deeply reduced in all models (C26 and BaF3, P<0.001; MC38 and APCMin/+ , P<0.05) independently of anorexia. This reduction occurred early in the liver (P<0.001; before the onset of cachexia), compared to the ileum and skeletal muscle (P<0.01; pre-cachexia stage), and was intrinsically related to cachexia (C26 vs. NC26, P<0.001). We demonstrate a differential modulation of AHR activation in the liver (through the IL-6/hypoxia-inducing factor 1α pathway) compared to the ileum (attributed to the decreased levels of indolic AHR ligands, P<0.001), and the muscle. In cachectic mice, FICZ treatment reduced hepatic inflammation: expression of cytokines (Ccl2, P=0.005; Cxcl2, P=0.018; Il1b, P=0.088) with similar trends at the protein levels, expression of genes involved in the acute-phase response (Apcs, P=0.040; Saa1, P=0.002; Saa2, P=0.039; Alb, P=0.003), macrophage activation (Cd68, P=0.038) and extracellular matrix remodelling (Fga, P=0.008; Pcolce, P=0.025; Timp1, P=0.003). We observed a decrease in blood glucose in cachectic mice (P<0.0001), which was also improved by FICZ treatment (P=0.026) through hepatic transcriptional promotion of a key marker of gluconeogenesis, namely, G6pc (C26 vs. C26+FICZ, P=0.029). Strikingly, these benefits on glycaemic disorders occurred independently of an amelioration of the gut barrier dysfunction. In cancer patients, the hepatic expression of G6pc was correlated to Cyp1a1 (Spearman's ρ=0.52, P=0.089) and Cyp1a2 (Spearman's ρ=0.67, P=0.020). With this set of studies, we demonstrate that impairment of AHR signalling contributes to hepatic inflammatory and metabolic disorders characterizing cancer cachexia, paving the way for innovative therapeutic strategies in this context.

Ameliorating effects of cystine and theanine in a cancer cachexia mouse model

Cachexia is a common cancer complication and is associated with weight loss and anorexia. In this study, we investigated the ameliorating effects of cystine and theanine on cancer cachexia using a mouse model. In mice carrying the colon cancer cell line C-26, there was a suppression of body weight increase and reduction in both internal fat and lower limb muscles. Repeated cystine and theanine administration significantly prevented weight loss, internal fat loss, lower limb muscle loss, and serum IL-6 increase in the cachexia model. These results suggested that cystine and theanine may be effective in ameliorating cancer cachexia.

Poor Renal Function and a High Modified Glasgow Prognostic Score Are Predictive Factors for Nedaplatin/5-Fluorouracil Combination Therapy-induced Febrile Neutropenia.

Nedaplatin (NDP)/5-fluorouracil (5-FU) combination therapy frequently causes severe neutropenia and febrile neutropenia (FN). However, there is no consensus on the risk factors for FN caused by NDP/5-FU combination therapy. Mouse models of cancer cachexia are known to be susceptible to infections. Conversely, the modified Glasgow prognostic score (mGPS) is believed to reflect cancer cachexia. We hypothesized that mGPS is a predictive factor for FN caused by NDP/5-FU combination therapy. We analyzed the relationship between mGPS and FN in patients who received NDP/5-FU combination therapy at Nagasaki University Hospital using multivariate logistic analysis. In total, 157 patients were studied, 20 of whom developed FN (12.7%). Multivariate analysis revealed that mGPS 1-2 [odds ratio (OR)=4.13, 95% confidence interval (CI)=1.42-12.02, p=0.009] and creatinine clearance <54.4 ml/min (OR=5.81, 95% CI=1.81-18.59, p=0.003) were significantly associated with the development of FN. Several guidelines suggest that patients receiving chemotherapy with an FN rate 10-20% should be considered for prophylactic granulocyte colony-stimulating factor (G-CSF), depending on the individual patient's risk of developing FN. When NDP/5-FU combination therapy is administered to patients with risk factors identified in this study, prophylactic administration of G-CSF should be considered. In addition, the neutrophil count and axillary temperature should be monitored more frequently.

Breast cancer cell-derived exosome-delivered microRNA-155 targets UBQLN1 in adipocytes and facilitates cancer cachexia-related fat loss.

Cachexia occurrence and development are associated with loss of white adipose tissues, which may be involved with cancer-derived exosomes. This study attempted to characterize the functional mechanisms of bc cell-derived exosomes-loaded microRNA (miR)-155 in cancer cachexia-related fat loss. Exosomes were incubated with preadipocytes and cellular lipid droplet accumulation was observed using oil red O staining. Western blots evaluated the cellular levels of lipogenesis marker peroxisome proliferator activated receptor gamma (PPARγ) and adiponectin, C1Q and collagen domain containing (AdipoQ). Differentiated adipocytes were incubated with exosomes, and phosphate hormone sensitive lipase (P-HSL), adipose triglyceride lipase (ATGL), and glycerol were detected in adipocytes, in addition to uncoupling protein 1 (UCP1) and leptin levels. A mouse model of cancer cachexia was established where cancer exosomes were injected intravenously. The changes in body weight and tumor-free body weights were recorded and serum glycerol levels and lipid accumulation in adipose tissues were determined. Also, the relationship between miR-155 and UBQLN1 was predicted and verified. bc exosome treatment reduced PPARγ and AdipoQ protein levels, promoted the levels of P-HSL and ATGL proteins, facilitated glycerol release, increased UCP1 expression, and lowered leptin expression in adipocytes. Exosomal miR-155 inhibited lipogenesis in preadipocytes and boosted the browning of white adipose tissues. miR-155 downregulation alleviated cancer exosome-induced browning of white adipose tissues and fat loss. Mechanistically, miR-155 targeted UBQLN1, and UBQLN1 upregulation reversed the impacts of cancer exosomes. miR-155 loaded by bc cell-derived exosomes significantly affects white adipose browning and inhibition of cancer-derived exosomes.

Abstract 364: Multi-omics approaches revealed the involvement of immune cells in skeletal muscles of lung cancer cachexia mouse model

Abstract Cancer-associated cachexia (CAC) is a multifactorial syndrome characterized by loss of body weight and skeletal muscle mass that cannot be fully recovered by nutritional support. It accounts for approximately 20 % of cancer-related deaths. However, there are no approved treatments for CAC yet. In order to better understand CAC, we wanted to apply the multi-omics approaches to simultaneously assess tumors and skeletal muscles in CAC mouse models. First, we established a lung cancer cachexia mouse model by orthotopic transplantation of KRAS-mutant lung cancer cells. Lung tumor-bearing mice developed cachexia at 7 weeks post injection, showing over 20 % of body weight loss and wasting of skeletal muscles and fats. The histological and immunoblotting analyses revealed degradation of gastrocnemius (GA) and tibialis anterior (TA) muscles in CAC group. Then, we performed the bulk RNA sequencing to assess transcriptomic changes in lung tumors and GA muscles of CAC mice. In lung tumors, genes associated to ATP metabolic process was upregulated. However, skeletal muscles of CAC mice showed upregulation of genes involved in protein degradation and immune responses, while genes related to energy metabolism were downregulated. Notably, the immunohistochemical staining revealed the increased numbers of infiltrating macrophages and CD8+ T cells in skeletal muscles of CAC mice. These data suggest the involvement of immune cells in lung cancer-associated cachexia. To further identify the distinct immune cell populations involved in CAC, the single cell RNA sequencing was conducted using CD45+ immune cells infiltrated into GA muscles of CAC mice. The enrichment of natural killer cells, dendritic cells and T cells was detected in GA of CAC mice. Moreover, we confirmed the roles of the infiltrating immune cells by using the neutralizing antibodies in CAC mice. Taken together, these data suggest the involvement of the immune cells in the skeletal muscle wasting of CAC mice. These multi-omics approaches will shed light on development of therapeutics for cancer-induced cachexia. Citation Format: Se-Young Park, Bomi Kim, Myunggyo Lee, Haeseung Lee, Na-Young Song. Multi-omics approaches revealed the involvement of immune cells in skeletal muscles of lung cancer cachexia mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 364.

Babao Dan Alleviates Cancer Cachexia in Mice Via Inhibiting IL-6/STAT3 Signaling Pathway.

Cancer cachexia is a common but severe condition that causes muscle wasting, body weight loss, and progressive functional impairment, affecting over 50% of cancer patients. Currently, there are no effective treatments that can alleviate cachexia, and hence the discovery of new therapeutics that can effectively prevent or even reverse cancer cachexia is crucial. Babao Dan (BBD) is a Traditional Chinese Medicine (TCM) formula that has been used clinically in combating various cancers, however, its therapeutic potential in alleviating cancer cachexia remains unexplored. Our current study aims to determine the anti-cachectic effects of BBD treatment in alleviating cancer cachexia, as well as determining the underlying mechanisms involved. Mouse models of cancer cachexia were induced via implantation of CT26 colon adenocarcinoma cells, and the anti-cachectic effects and mechanisms of BBD were determined via examinations of body weight and muscle mass, as well as serum and muscle markers of cachexia and muscle atrophy. CT26 tumor implantation reduced in the rapid occurrence of cancer cachexia characterized by marked reductions in body weight and muscle mass, functional decrease in muscle function and accelerated deaths. BBD administration not only demonstrated robust anti-cachectic ability via preventing decreases in body weight, muscle mass, and muscle atrophy, but also markedly prolonged survival. The effects of BBD in alleviating cancer cachexia and its associated adverse effects were due to its ability in preventing the activation of IL-6/STAT3 signaling post-CT26 tumor implantation. Our findings demonstrated the robust ability of BBD in preventing cancer cachexia and alleviating the main cachexia-induced symptoms as well as prolonging survival via inhibiting activation of IL-6/STAT3 signaling pathway. Therefore, our study demonstrating the strong anti-cachectic effects of BBD in mice may provide a theoretical basis for the use of BBD as a safe and effective drug in the treatment of cancer cachexia.

GDF15 neutralization restores muscle function and physical performance in a mouse model of cancer cachexia

Cancer cachexia is a disorder characterized by involuntary weight loss and impaired physical performance. Decline in physical performance of patients with cachexia is associated with poor quality of life, and currently there are no effective pharmacological interventions that restore physical performance. Here we examine the effect of GDF15 neutralization in a mouse model of cancer-induced cachexia (TOV21G) that manifests weight loss and muscle function impairments. With comprehensive assessments, our results demonstrate that cachectic mice treated with the anti-GDF15 antibody mAB2 exhibit body weight gain with near-complete restoration of muscle mass and markedly improved muscle function and physical performance. Mechanistically, the improvements induced by GDF15 neutralization are primarily attributed to increased caloric intake, while altered gene expression in cachectic muscles is restored in caloric-intake-dependent and -independent manners. The findings indicate potential of GDF15 neutralization as an effective therapy to enhance physical performance of patients with cachexia.

Analysis of different adipose depot gene expression in cachectic patients with gastric cancer

PurposeThis study aimed to identify the differentially expressed genes (DEGs) that contributed to the different amount of fat loss between subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) among cachectic patients.MethodsRNA sequencing was performed and bioinformatic tools were utilized to analyze the biological functions and construct regulation networks of DEGs. We presumed that iroquois homeobox 1 (IRX1) to be a hub gene and analyzed its clinical significance. Mouse model of cancer cachexia was established and differences between SAT and VAT were compared. The function of IRX1 on lipid metabolism was clarified by Oil Red O staining, qRT-PCR, and Western blotting in adipocytes.ResultsA total of 455 DEGs were screened between SAT and VAT in cachectic patients. Several hub genes were selected and IRX1 was presumed to contribute to the pathological difference between SAT and VAT in cancer cachexia. Patients with higher expression of IRX1 in SAT than VAT revealed significantly higher weight loss, IL-6 and TNF-α, as well as lower BMI, SAT, and VAT area. IRX1 expression in SAT was negatively correlated with SAT area. In cachectic mice, the expression of IRX1 in SAT was significantly higher than that in VAT. The inhibition effect on adipogenesis exerted by IRX1 was also proved in vitro.ConclusionThese data supported that DEGs contribute to the different degrees of fat loss among adipose depots in cachectic patients. IRX1 in SAT promoted fat loss by inhibiting adipocyte differentiation and adipogenesis.

Lcn2 mediates adipocyte-muscle-tumor communication and hypothermia in pancreatic cancer cachexia

ObjectiveAdipose tissue is the largest endocrine organ. When activated by cancer cells, adipocytes secrete adipocytokines and release fatty acids, which are then transferred to cancer cells and used for structural and biochemical support. How this metabolic symbiosis between cancer cells and adipocytes affects skeletal muscle and thermogenesis during cancer cachexia is unknown. Cancer cachexia is a multiorgan syndrome and how the communication between tissues is established has yet to be determined. We investigated adipose tissue secretory factors and explored their role in crosstalk of adipocytes, muscle, and tumor during pancreatic cancer cachexia. MethodsWe used a pancreatic cancer cachexia mouse model generated by syngenic implantation of pancreatic ductal adenocarcinoma (PDAC) cells (KPC) intraperitoneally into C57BL/6 mice and Lcn2-knockout mice. For in vitro studies, adipocytes (3T3-L1 and primary adipocytes), cachectic cancer cells (Panc0203), non-cachectic cancer cells (Du145 cells), and skeletal muscle cells (C2C12 myoblasts) were used. ResultsTo identify molecules involved in the crosstalk of adipose tissue with muscle and tumors, we treated 3T3-L1 adipocytes with conditioned medium (CM) from cancer cells. Upon screening the secretomes from PDAC-induced adipocytes, several adipocytokines were identified, including lipocalin 2 (Lcn2). We investigated Lcn2 as a potential mediator of cachexia induced by adipocytes in response to PDAC. During tumor progression, mice exhibited a decline in body weight gain, which was accompanied by loss of adipose and muscle tissues. Tumor-harboring mice developed drastic hypothermia because of a dramatic loss of fat in brown adipose tissue (BAT) and suppression of the thermogenesis pathway. We inhibited Lcn2 with an anti-Lcn2 antibody neutralization or genomic ablation in mice. Lcn2 deficiency significantly improved body temperature in tumor-bearing mice, which was supported by the increased expression of Ucp1 and β3-adrenergic receptor in BAT. In addition, Lcn2 inhibition abrogated the loss of fat and muscle in tumor-bearing mice. In contrast to tumor-bearing WT mice, the corresponding Lcn2-knockout mice showed reduced ATGL expression in iWAT and decreased the expression of muscle atrophy molecular markers MuRF-1 and Fbx32. ConclusionsThis study showed that Lcn2 is causally involved in the dysregulation of adipose tissue–muscle-tumor crosstalk during pancreatic cancer cachexia. Therapeutic targets that suppress Lcn2 may minimize the progression of cachexia.

Alantolactone ameliorates cancer cachexia-associated muscle atrophy mainly by inhibiting the STAT3 signaling pathway

BackgroundCancer cachexia is a serious metabolic disorder syndrome that is responsible for the deaths of approximately 30% of patients with cancer, but effective drugs for cancer cachexia are still lacking. Inflammatory cytokines such as TNF-α or IL-6 are involved in the induction of skeletal muscle atrophy and fat depletion in patients with cancer cachexia. PurposeIn this study, we assessed the therapeutic effects of the natural compound alantolactone (AL) on cancer cachexia and tried to clarify the mechanisms by which it ameliorates muscle atrophy. MethodsThe C26 tumor-bearing cancer cachexia mouse model was used to evaluate the efficacy of AL in alleviating cancer cachexia in vivo. The levels of IL-6 or TNF-α in mouse serum were detected using ELISA kits. Cultured C2C12 myotubes and 3T3-L1 adipocytes treated with conditioned medium of C26 tumor cells, IL-6 or TNF-α were employed as in vitro cancer cachexia models to examine the effects of AL in vitro. ResultsAL (5 or 10 mg/kg, qd, i.p.) protected mice with C26 tumors and cachexia from a loss of body weight and muscle wasting but only slightly ameliorated fat loss. The circulating level of IL-6 but not TNF-α was significantly decreased by AL. AL treatment significantly inhibited STAT3 activation in the gastrocnemius (GAS) muscle of cancer cachexia mice. AL (0.125, 0.25, 0.5 and 1 µM) dose-dependently ameliorated myotube atrophy and STAT3 activation in cultured C2C12 myotubes induced by conditioned medium from C26 tumor cells. AL also ameliorated C2C12 myotube atrophy induced by IL-6 and inhibited IL-6-mediated STAT3 activation. AL exhibited weak effects on ameliorating TNF-α-mediated myotube atrophy and NF-κB activation. Only AL at high doses of more than 5 µM ameliorated lipolysis and STAT3 activation induced in mature 3T3-L1 adipocytes by conditioned medium from C26 tumor cells. ConclusionsAL significantly ameliorated muscle atrophy in a cancer cachexia model mainly through the inhibition of the STAT3 pathway. AL might be a promising lead compound in the development of drug candidates for cancer cachexia therapy.

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

Mol. Nutr. Food Res. 2021, 65, 202100268 DOI: 10.1002/mnfr.202100268 In article number 2100268, Martha A. Belury and co-workers found that dietary supplementation of naringenin improves multiple aspects of metabolic disturbance during cancer cachexia progression in the C-26 mouse model. The cover image by graphic designer Pamela Galante is a pattern depicting food sources of naringenin, the metabolic interplay between tumor, adipose, and muscle tissues, inflammation, and the insulin receptor.

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.