A placebo-controlled double blind trial of etanercept for the cancer anorexia/weight loss syndrome: results from N00C1 from the North Central Cancer Treatment Group

Cancer anorexia-cachexia syndrome is characterized by more than one inflammatory pathway

BACKGROUND

The interdependence of cytokines and appetite-modifying hormones implicated in cancer anorexia-cachexia syndrome (CACS) remains unclear. This study aimed to regroup these cytokines and hormones into distinct inflammatory (or non-inflammatory) pathways and determine whether these pathways can classify patients with CACS phenotypes.

METHODS

Clinical characteristics of 133 patients [61.7% male; mean age = 63.4 (SD: 13.1) years] with advanced cancer prior to oncology treatments were documented, including weight loss history. Patients completed the Functional Assessment of Anorexia-Cachexia Therapy (FAACT) questionnaire and Timed Up and Go test and had their sex-standardized skeletal muscle index (z-SMI) and fat mass index (z-FMI) derived using computed tomography scans. Their plasma levels of cytokines and appetite-modifying hormones were also determined. Date of death was recorded. Exploratory factor analysis (EFA) was used to regroup 15 cytokines and hormone into distinct inflammatory pathways (factors). For each patient, regression factor scores (RFS), which tell how strongly the patient associates with each factor, were derived. Two-step cluster analysis on the RFS was used to classify patients into groups. CACS phenotypes were correlated with RFS and compared between groups. Groups' survival was estimated using Kaplan-Meier analysis.

RESULTS

Patients had low z-SMI (mean = -3.78 cm2/m2; SD: 8.88) and z-FMI (mean = 0.08 kg2/m2; SD: 56.25), and 62 (46.6%) had cachexia. EFA identified three factors: (F-1) IFN-γ, IL-1β, Il-4, IL-6, IL-10, IL-12, TGFβ1 (positive contribution), and IL-18 (negative); (F-2) IL-8, IL-18, MCP-1, TGFβ1, TNF-α (positive), and ghrelin (negative); and (F-3) TRAIL and leptin (positive), and TGFβ1 and adiponectin (negative). RFS-1 was associated with cachexia (P = 0.002); RFS-2, with higher CRP (P < 0.0001) and decreased physical function (P = 0.01); and RFS-3 with better appetite (P = 0.04), lower CRP (P = 0.002), higher z-SMI (P = 0.04) and z-FMI (P < 0.0001), and less cachexia characteristics (all P < 0.001). Four patient groups were identified with specific RFS clusters aligning with the CACS continuum from no cachexia to pre-cachexia, cachexia, and terminal cachexia. Compared to the other two groups, groups 1 and 2 had higher plasma levels of IL-18 and TRAIL. Group 1 also had lower inflammatory cytokines, adiponectin, and CRP compared to the other three groups. Group 3 had inflammatory cytokine levels similar to group 2, except for TNF-α and leptin which were lower. Group 4 had very high inflammatory cytokines, adiponectin, and CRP compared to the other 3 groups (all P < 0.0001). Groups 3 and 4 had worse cachexia characteristics (P < 0.05) and shorter survival (log rank: P = 0.0009) than the other two groups.

CONCLUSIONS

This exploratory study identified three distinct pathways of inflammation, or lack thereof, characterizing different CACS phenotypes.

Oncostatin M signaling drives cancer-associated skeletal muscle wasting

Progressive weakness and muscle loss are associated with multiple chronic conditions, including muscular dystrophy and cancer. Cancer-associated cachexia, characterized by dramatic weight loss and fatigue, leads to reduced quality of life and poor survival. Inflammatory cytokines have been implicated in muscle atrophy; however, available anticytokine therapies failed to prevent muscle wasting in cancer patients. Here, we show that oncostatin M (OSM) is a potent inducer of muscle atrophy. OSM triggers cellular atrophy in primary myotubes using the JAK/STAT3 pathway. Identification of OSM targets by RNA sequencing reveals the induction of various muscle atrophy-related genes, including Atrogin1. OSM overexpression in mice causes muscle wasting, whereas muscle-specific deletion of the OSM receptor (OSMR) and the neutralization of circulating OSM preserves muscle mass and function in tumor-bearing mice. Our results indicate that activated OSM/OSMR signaling drives muscle atrophy, and the therapeutic targeting of this pathway may be useful in preventing muscle wasting.

Appetite and dietary intake endpoints in cancer cachexia clinical trials: Systematic Review 2 of the cachexia endpoints series

There is no consensus on the optimal endpoint(s) in cancer cachexia trials. Endpoint variation is an obstacle when comparing interventions and their clinical value. The aim of this systematic review was to summarize and evaluate endpoints used to assess appetite and dietary intake in cancer cachexia clinical trials. A search for studies published from 1 January 1990 until 2 June 2021 was conducted using MEDLINE, Embase and Cochrane Central Register of Controlled Trials. Eligible studies examined cancer cachexia treatment versus a comparator in adults with assessments of appetite and/or dietary intake as study endpoints, a sample size ≥40 and an intervention lasting ≥14 days. Reporting was in line with PRISMA guidance, and a protocol was published in PROSPERO (2022 CRD42022276710). This review is part of a series of systematic reviews examining cachexia endpoints. Of the 5975 articles identified, 116 were eligible for the wider review series and 80 specifically examined endpoints of appetite (65 studies) and/or dietary intake (21 studies). Six trials assessed both appetite and dietary intake. Appetite was the primary outcome in 15 trials and dietary intake in 7 trials. Median sample size was 101 patients (range 40-628). Forty-nine studies included multiple primary tumour sites, while 31 studies involved single primary tumour sites (15 gastrointestinal, 7 lung, 7 head and neck and 2 female reproductive organs). The most frequently reported appetite endpoints were visual analogue scale (VAS) and numerical rating scale (NRS) (40%). The appetite item from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) C30/C15 PAL (38%) and the appetite question from North Central Cancer Treatment Group anorexia questionnaire (17%) were also frequently applied. Of the studies that assessed dietary intake, 13 (62%) used food records (prospective registrations) and 10 (48%) used retrospective methods (24-h recall or dietary history). For VAS/NRS, a mean change of 1.3 corresponded to Hedge's g of 0.5 and can be considered a moderate change. For food records, a mean change of 231 kcal/day or 11 g of protein/day corresponded to a moderate change. Choice of endpoint in cachexia trials will depend on factors pertinent to the trial to be conducted. Nevertheless, from trials assessed and available literature, NRS or EORTC QLQ C30/C15 PAL seems suitable for appetite assessments. Appetite and dietary intake endpoints are rarely used as primary outcomes in cancer cachexia. Dietary intake assessments were used mainly to monitor compliance and are not validated in cachexia populations. Given the importance to cachexia studies, dietary intake endpoints must be validated before they are used as endpoints in clinical trials.

The roles of P-selectin in cancer cachexia

P-selectin, a cell adhesion molecule of the selectin family, is expressed on the surface of activated endothelial cells (ECs) and platelets. Binding of P-selectin to P-selectin glycoprotein ligand-1 (PSGL-1) supports the leukocytes capture and rolling on stimulated ECs and increases the aggregation of leukocytes and activated platelets. Cancer cachexia is a systemic inflammation disorder characterized by metabolic disturbances, reduced body weight, loss of appetite, fat depletion, and progressive muscle atrophy. Cachexia status is associated with increased pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), which activates ECs to release P-selectin. Single-nucleotide polymorphisms (SNPs) loci of P-selectin encoding gene SELP are associated with higher level of plasma P-selectin and increase the susceptibility to cachexia in cancer patients. Elevated P-selectin expression has been observed in the hypothalamus, liver, and gastrocnemius muscle in animal models with cancer cachexia. Increased P-selectin may cause excessive inflammatory processes, muscle atrophy, and blood hypercoagulation, thus facilitating the development of cancer cachexia. In this review, physiological functions of P-selectin and its potential roles in cancer cachexia have been summarized. We also discuss the therapeutic potential of P-selectin inhibitors for the treatment of cancer cachexia.

Muscle wasting: emerging pathways and potential drug targets

Muscle wasting is a serious comorbidity associated with many disorders, including cancer, kidney disease, heart failure, and aging. Progressive loss of skeletal muscle mass negatively influences prognosis and survival, and is often accompanied by frailty and poor quality of life. Clinical trials testing therapeutics against muscle wasting have yielded limited success. Some therapies improved muscle mass in patients without appreciable differences in physical performance. This review article discusses emerging pathways that regulate muscle atrophy, including oncostatin M (OSM) and ectodysplasin A2 (EDA2) receptor (EDA2R) signaling, outcomes of recent clinical trials, and potential drug targets for future therapies.

Update on the treatment of cancer cachexia

Cancer cachexia is a complex multifaceted syndrome involving functional impairment and changes in body composition that cannot be reversed by nutritional support. Cancer cachexia is characterized by decreased skeletal muscle mass, increased lipolysis, and decreased food intake. Cancer cachexia decreases chemotherapy tolerance as well as quality of life. However, because no fully effective interventions are available, cancer cachexia remains an unmet need in cancer treatment. In recent years, several discoveries and treatments for cancer cachexia have been studied, and guidelines have been published. We believe that the development of effective strategies for the diagnosis and treatment of cancer cachexia will lead to breakthroughs in cancer treatment.

Measuring symptoms and toxicities: a 35-year experience

PURPOSE

When conducting trials aimed at the improvement of cancer-related and/or cancer treatment-related toxicities, it is important to determine the best means of measuring patients' symptoms.

METHODS

The authors of this current manuscript have an extensive experience with the conduct of symptom-control clinical trials. This experience is utilized to provide insight into the best means of measuring symptoms caused by cancer and/or cancer therapy.

RESULTS

Patient-reported outcome data are preferable for measuring bothersome symptoms, for determining toxicities caused by treatment approaches, and offer more accurate and detailed information compared with health care practitioners recording their impressions of patient experiences. Well-validated patient friendly measures are recommended when they are available. When such are not readily available, face-valid, single-item numerical rating scales are effective instruments to document both treatment trial outcomes and cancer treatment side effects/toxicities.

CONCLUSION

The use of numerical rating scales are effective means of measuring symptoms caused by cancer, by cancer treatments, and/or alleviated by symptom control treatment approaches.

Cancer cachexia: molecular mechanisms and treatment strategies

Muscle wasting is a consequence of physiological changes or a pathology characterized by increased catabolic activity that leads to progressive loss of skeletal muscle mass and strength. Numerous diseases, including cancer, organ failure, infection, and aging-associated diseases, are associated with muscle wasting. Cancer cachexia is a multifactorial syndrome characterized by loss of skeletal muscle mass, with or without the loss of fat mass, resulting in functional impairment and reduced quality of life. It is caused by the upregulation of systemic inflammation and catabolic stimuli, leading to inhibition of protein synthesis and enhancement of muscle catabolism. Here, we summarize the complex molecular networks that regulate muscle mass and function. Moreover, we describe complex multi-organ roles in cancer cachexia. Although cachexia is one of the main causes of cancer-related deaths, there are still no approved drugs for cancer cachexia. Thus, we compiled recent ongoing pre-clinical and clinical trials and further discussed potential therapeutic approaches for cancer cachexia.

EDA2R-NIK signalling promotes muscle atrophy linked to cancer cachexia

Skeletal muscle atrophy is a hallmark of the cachexia syndrome that is associated with poor survival and reduced quality of life in patients with cancer¹. Muscle atrophy involves excessive protein catabolism and loss of muscle mass and strength². An effective therapy against muscle wasting is currently lacking because mechanisms driving the atrophy process remain incompletely understood. Our gene expression analysis in muscle tissues indicated upregulation of ectodysplasin A2 receptor (EDA2R) in tumour-bearing mice and patients with cachectic cancer. Here we show that activation of EDA2R signalling promotes skeletal muscle atrophy. Stimulation of primary myotubes with the EDA2R ligand EDA-A2 triggered pronounced cellular atrophy by induction of the expression of muscle atrophy-related genes Atrogin1 and MuRF1. EDA-A2-driven myotube atrophy involved activation of the non-canonical NFĸB pathway and was dependent on NFκB-inducing kinase (NIK) activity. Whereas EDA-A2 overexpression promoted muscle wasting in mice, deletion of either EDA2R or muscle NIK protected tumour-bearing mice from loss of muscle mass and function. Tumour-induced oncostatin M (OSM) upregulated muscle EDA2R expression, and muscle-specific oncostatin M receptor (OSMR)-knockout mice were resistant to tumour-induced muscle wasting. Our results demonstrate that EDA2R-NIK signalling mediates cancer-associated muscle atrophy in an OSM-OSMR-dependent manner. Thus, therapeutic targeting of these pathways may be beneficial in prevention of muscle loss.

Understanding the relationship between cancer associated cachexia and hypoxia-inducible factor-1

Cancer-associated cachexia (CAC) is a multifactorial disorder characterized by an unrestricted loss of body weight as a result of muscle and adipose tissue atrophy. Cachexia is influenced by several factors, including decreased metabolic activity and food intake, an imbalance between energy uptake and expenditure, excessive catabolism, and inflammation. Cachexia is highly associated with all types of cancers responsible for more than half of cancer-related mortalities worldwide. In healthy individuals, adipose tissue significantly regulates energy balance and glucose homeostasis. However, in metastatic cancer patients, CAC occurs mainly because of an imbalance between muscle protein synthesis and degradation which are organized by certain extracellular ligands and associated signaling pathways. Under hypoxic conditions, hypoxia-inducible factor-1 (HIF-1α) accumulated and translocated to the nucleus and activate numerous genes involved in cell survival, invasion, angiogenesis, metastasis, metabolic reprogramming, and cancer stemness. On the other hand, the ubiquitination proteasome pathway is inhibited during low O2 levels which promote muscle wasting in cancer patients. Therefore, understanding the mechanism of the HIF-1 pathway and its metabolic adaptation to biomolecules is important for developing a novel therapeutic method for cancer and cachexia therapy. Even though many HIF inhibitors are already in a clinical trial, their mechanism of action remains unknown. With this background, this review summarizes the basic concepts of cachexia, the role of inflammatory cytokines, pathways connected with cachexia with special reference to the HIF-1 pathway and its regulation, metabolic changes, and inhibitors of HIFs.

Brown adipose tissue is not associated with cachexia or increased mortality in a retrospective study of patients with cancer

Although brown fat is strongly associated with a constellation of cardiometabolic benefits in animal models and humans, it has also been tied to cancer cachexia. In humans, cancer-associated cachexia increases mortality, raising the possibility that brown fat in this context may be associated with increased cancer death. However, the effect of brown fat on cancer-associated cachexia and survival in humans remains unclear. Here, we retrospectively identify patients with and without brown fat on fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET) scans obtained as part of routine cancer care and assemble a cohort to address these questions. We did not find an association between brown fat status and cachexia. Furthermore, we did not observe an association between brown fat and increased mortality in patients with cachexia. Our analyses controlled for confounding factors including age at cancer diagnosis, sex, body mass index, cancer site, cancer stage, outdoor temperature, comorbid conditions (heart failure, type 2 diabetes mellitus, coronary artery disease, hypertension, dyslipidemia, cerebrovascular disease), and β-blocker use. Taken together, our results suggest that brown fat is not linked to cancer-associated cachexia and does not worsen overall survival in patients with cachexia.NEW & NOTEWORTHY This study finds that brown fat is not linked to cancer-associated cachexia. Moreover, this work shows that brown fat does not worsen overall survival in patients with cachexia.

Creatine modulates cellular energy metabolism and protects against cancer cachexia-associated muscle wasting

Cancer cachexia is a multifactorial syndrome defined by progressive loss of body weight with specific depletion of skeletal muscle and adipose tissue. Since there are no FDA-approved drugs that are available, nutritional intervention is recommended as a supporting therapy. Creatine supplementation has an ergogenic effect in various types of sports training, but the regulatory effects of creatine supplementation in cancer cachexia remain unknown. In this study, we investigated the impact of creatine supplementation on cachectic weight loss and muscle loss protection in a tumor-bearing cachectic mouse model, and the underlying molecular mechanism of body weight protection was further assessed. We observed decreased serum creatine levels in patients with cancer cachexia, and the creatine content in skeletal muscle was also significantly decreased in cachectic skeletal muscle in the C26 tumor-bearing mouse model. Creatine supplementation protected against cancer cachexia-associated body weight loss and muscle wasting and induced greater improvements in grip strength. Mechanistically, creatine treatment altered the dysfunction and morphological abnormalities of mitochondria, thus protecting against cachectic muscle wasting by inhibiting the abnormal overactivation of the ubiquitin proteasome system (UPS) and autophagic lysosomal system (ALS). In addition, electron microscopy revealed that creatine supplementation alleviated the observed increase in the percentage of damaged mitochondria in C26 mice, indicating that nutritional intervention with creatine supplementation effectively counteracts mitochondrial dysfunction to mitigate muscle loss in cancer cachexia. These results uncover a previously uncharacterized role for creatine in cachectic muscle wasting by modulating cellular energy metabolism to reduce the level of muscle cell atrophy.

Targeting cancer cachexia: Molecular mechanisms and clinical study

Cancer cachexia is a complex systemic catabolism syndrome characterized by muscle wasting. It affects multiple distant organs and their crosstalk with cancer constitute cancer cachexia environment. During the occurrence and progression of cancer cachexia, interactions of aberrant organs with cancer cells or other organs in a cancer cachexia environment initiate a cascade of stress reactions and destroy multiple organs including the liver, heart, pancreas, intestine, brain, bone, and spleen in metabolism, neural, and immune homeostasis. The role of involved organs turned from inhibiting tumor growth into promoting cancer cachexia in cancer progression. In this review, we depicted the complicated relationship of cancer cachexia with the metabolism, neural, and immune homeostasis imbalance in multiple organs in a cancer cachexia environment and summarized the treatment progress in recent years. And we discussed the molecular mechanism and clinical study of cancer cachexia from the perspective of multiple organs metabolic, neurological, and immunological abnormalities. Updated understanding of cancer cachexia might facilitate the exploration of biomarkers and novel therapeutic targets of cancer cachexia.

Informed consent and biological agents in rheumatology and internal medicine

BACKGROUND

The need for highly effective therapies in rheumatologic diseases has led to the widespread and growing use of a heterogeneous class of molecules called biological agents. The increasing experience with biological agents has raised concerns about safety and efficacy issues that need to be discussed in the informed consent acquisition process.

METHODS

The authors performed a review of the literature on biological agents focusing on their most important characteristics concerning the informed consent procedures.

RESULTS

No studies specifically addressed the issue of informed consent in patients receiving biological agents. Several studies reported data about off-label use of biological agents usually with no obvious attention to informed consent shortcomings.

CONCLUSION

The reported association between biological agents and serious infections or malignancies, including reactivation of latent tuberculosis, needs specific disclosure in informed consent acquisition, together with information about the possible efficacy in clinical contexts often characterized by resistance to previous treatments. Ethical and clinical issues bound to the need for experimenting with new agents with potentially serious adverse effects deserve specific attention. Studies aimed at evaluating mental capacity to consent in subjects receiving biological agents are required.

Cancer Cachexia: Signaling and Transcriptional Regulation of Muscle Catabolic Genes

Simple Summary

An uncontrollable loss in the skeletal muscle of cancer patients which leads to a significant reduction in body weight is clinically referred to as cancer cachexia (CC). While factors derived from the tumor environment which trigger various signaling pathways have been identified, not much progress has been made clinically to effectively prevent muscle loss. Deeper insights into the transcriptional and epigenetic regulation of muscle catabolic genes may shed light on key regulators which can be targeted to develop new therapeutic avenues.

Abstract

Cancer cachexia (CC) is a multifactorial syndrome characterized by a significant reduction in body weight that is predominantly caused by the loss of skeletal muscle and adipose tissue. Although the ill effects of cachexia are well known, the condition has been largely overlooked, in part due to its complex etiology, heterogeneity in mediators, and the involvement of diverse signaling pathways. For a long time, inflammatory factors have been the focus when developing therapeutics for the treatment of CC. Despite promising pre-clinical results, they have not yet advanced to the clinic. Developing new therapies requires a comprehensive understanding of how deregulated signaling leads to catabolic gene expression that underlies muscle wasting. Here, we review CC-associated signaling pathways and the transcriptional cascade triggered by inflammatory cytokines. Further, we highlight epigenetic factors involved in the transcription of catabolic genes in muscle wasting. We conclude with reflections on the directions that might pave the way for new therapeutic approaches to treat CC.

Inflammatory Cytokine: An Attractive Target for Cancer Treatment

The relationship between inflammation and cancer has attracted attention for a long time. The inflammatory tumor microenvironment consists of inflammatory cells, chemokines, cytokines, and signaling pathways. Among them, inflammatory cytokines play an especially pivotal role in cancer development, prognosis, and treatment. Interleukins, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interferons, and vascular endothelial growth factor (VEGF) are the representative inflammatory cytokines in various cancers, which may promote or inhibit cancer progression. The pro-inflammatory cytokines are associated with advanced cancer stages, resistance to immunotherapy, and poor prognoses, such as in objective response and disease control rates, and progression-free and overall survival. In this review, we selected colorectal, pancreatic, breast, gastric, lung, and prostate cancers, which are well-reported for an association between cancer and inflammatory cytokines. The related cytokines and their effects on each cancer’s development and prognosis were summarized. In addition, the treatment strategies targeting inflammatory cytokines in each carcinoma were also described here. By understanding the biological roles of cancer-related inflammatory cytokines, we may modulate the inflammatory tumor microenvironment for potential cancer treatment.

Transforming Growth Factor-Beta Signaling in Cancer-Induced Cachexia: From Molecular Pathways to the Clinics

Cachexia is a metabolic syndrome consisting of massive loss of muscle mass and function that has a severe impact on the quality of life and survival of cancer patients. Up to 20% of lung cancer patients and up to 80% of pancreatic cancer patients are diagnosed with cachexia, leading to death in 20% of them. The main drivers of cachexia are cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), macrophage inhibitory cytokine 1 (MIC-1/GDF15) and transforming growth factor-beta (TGF-β). Besides its double-edged role as a tumor suppressor and activator, TGF-β causes muscle loss through myostatin-based signaling, involved in the reduction in protein synthesis and enhanced protein degradation. Additionally, TGF-β induces inhibin and activin, causing weight loss and muscle depletion, while MIC-1/GDF15, a member of the TGF-β superfamily, leads to anorexia and so, indirectly, to muscle wasting, acting on the hypothalamus center. Against this background, the blockade of TGF-β is tested as a potential mechanism to revert cachexia, and antibodies against TGF-β reduced weight and muscle loss in murine models of pancreatic cancer. This article reviews the role of the TGF-β pathway and to a minor extent of other molecules including microRNA in cancer onset and progression with a special focus on their involvement in cachexia, to enlighten whether TGF-β and such other players could be potential targets for therapy.

Cancer Cachexia and Antitumor Immunity: Common Mediators and Potential Targets for New Therapies

Cancer cachexia syndrome (CCS) is a multifactorial metabolic syndrome affecting a significant proportion of patients. CCS is characterized by progressive weight loss, alterations of body composition and a systemic inflammatory status, which exerts a major impact on the host’s innate and adaptive immunity. Over the last few years, the development of immune checkpoint inhibitors (ICIs) transformed the treatment landscape for a wide spectrum of malignancies, creating an unprecedented opportunity for long term remissions in a significant subset of patients. Early clinical data indicate that CCS adversely impairs treatment outcomes of patients receiving ICIs. We herein reviewed existing evidence on the potential links between the mechanisms that promote the catabolic state in CCS and those that impair the antitumor immune response. We show that the biological mediators and processes leading to the development of CCS may also participate in the modulation and the sustainment of an immune suppressive tumor microenvironment and impaired anti-tumor immunity. Moreover, we demonstrate that the deregulation of the host’s metabolic homeostasis in cancer cachexia is associated with resistance to ICIs. Further research on the interrelation between cancer cachexia and anti-tumor immunity is required for the effective management of resistance to immunotherapy in this specific but large subgroup of ICI treated individuals.

Cancer- and cardiac-induced cachexia: same fate through different inflammatory mediators?

BACKGROUND

Inflammation is widely recognized as the driving force of cachexia induced by chronic diseases; however, therapies targeting inflammation do not always reverse cachexia. Thus, whether inflammation per se plays an important role in the clinical course of cachectic patients is still a matter of debate.

AIMS

To give new insights into cachexia's pathogenesis and diagnosis, we performed a comprehensive literature search on the contribution of inflammatory markers to this syndrome, focusing on the noncommunicable diseases cancer and cardiovascular diseases.

METHODS

A systematic review was performed in PubMed using the keywords ("cancer" OR "cardiac" cachexia AND "human" OR "patient" AND "plasma" or "serum"). A total of 744 studies were retrieved and, from these, 206 were selected for full-text screening. In the end, 98 papers focusing on circulating biomarkers of cachexia were identified, which resulted in a list of 113 different mediators.

RESULTS

Data collected from the literature highlight the contribution of interleukin-6 (IL-6) and C-reactive protein (CRP) to cachexia, independently of the underlying condition. Despite not being specific, once the diagnosis of cachexia is established, CRP might help to monitor the effectiveness of anti-cachexia therapies. In cardiac diseases, B-type natriuretic peptide (BNP), renin, and obestatin might be putative markers of body wasting, whereas in cancer, growth differentiation factor (GDF) 15, transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) C seem to be better markers of this syndrome. Independently of the circulating mediators, NF-κB and JAK/STAT signaling pathways play a key role in bridging inflammation with muscle wasting; however, therapies targeting these pathways were not proven effective for all cachectic patients.

CONCLUSION

The critical and integrative analysis performed herein will certainly feed future research focused on the better comprehension of cachexia pathogenesis toward the improvement of its diagnosis and the development of personalized therapies targeting specific cachexia phenotypes.

Tumor cell anabolism and host tissue catabolism-energetic inefficiency during cancer cachexia

Cancer-associated cachexia (CC) is a pathological condition characterized by sarcopenia, adipose tissue depletion, and progressive weight loss. CC is driven by multiple factors such as anorexia, excessive catabolism, elevated energy expenditure by growing tumor mass, and inflammatory mediators released by cancer cells and surrounding tissues. In addition, endocrine system, systemic metabolism, and central nervous system (CNS) perturbations in combination with cachexia mediators elicit exponential elevation in catabolism and reduced anabolism in skeletal muscle, adipose tissue, and cardiac muscle. At the molecular level, mechanisms of CC include inflammation, reduced protein synthesis, and lipogenesis, elevated proteolysis and lipolysis along with aggravated toxicity and complications of chemotherapy. Furthermore, CC is remarkably associated with intolerance to anti-neoplastic therapy, poor prognosis, and increased mortality with no established standard therapy. In this context, we discuss the spatio-temporal changes occurring in the various stages of CC and highlight the imbalance of host metabolism. We provide how multiple factors such as proteasomal pathways, inflammatory mediators, lipid and protein catabolism, glucocorticoids, and in-depth mechanisms of interplay between inflammatory molecules and CNS can trigger and amplify the cachectic processes. Finally, we highlight current diagnostic approaches and promising therapeutic interventions for CC.

A systematic review examining the relationship between cytokines and cachexia in incurable cancer

Cancer cachexia is an unmet clinical need that affects more than 50% of patients with cancer. The systemic inflammatory response, which is mediated by a network of cytokines, has an established role in the genesis and maintenance of cancer as well as in cachexia; yet, the specific role of the cytokine milieu in cachexia requires elucidation. This systematic review aims to examine the relationship between cytokines and the cachexia syndrome in patients with incurable cancer. The databases MEDLINE, EMBASE, CINAHL, CENTRAL, PsycINFO, and Web of Science were searched for studies published between 01/01/2004 and 06/01/2020. Included studies measured cytokines and their relationship with cachexia and related symptoms/signs in adults with incurable cancer. After title screening (n = 5202), the abstracts (n = 1264) and the full-text studies (n = 322) were reviewed independently by two authors. The quality assessment of the selected papers was conducted using the modified Downs and Black checklist. Overall, 1277 patients with incurable cancer and 155 healthy controls were analysed in the 17 eligible studies. The mean age of the patients was 64 ± 15 (mean ± standard deviation). Only 34% of included participants were female. The included studies were assessed as moderate-quality to high-quality evidence (mean quality score: 7.8; range: 5-10). A total of 31 cytokines were examined in this review, of which interleukin-6 (IL-6, 14 studies) and tumour necrosis factor-α (TNF-α, 12 studies) were the most common. The definitions of cachexia and the weight-loss thresholds were highly variable across studies. Although the data could not be meta-analysed due to the high degree of methodological heterogeneity, the findings were discussed in a systematic manner. IL-6, TNF-α, and IL-8 were greater in cachectic patients compared with healthy individuals. Also, IL-6 levels were higher in cachectic participants as opposed to non-cachectic patients. Leptin, interferon-γ, IL-1β, IL-10, adiponectin, and ghrelin did not demonstrate any significant difference between groups when individuals with cancer cachexia were compared against non-cachectic patients or healthy participants. These findings suggest that a network of cytokines, commonly IL-6, TNF-α, and IL-8, are associated with the development of cachexia. Yet, this relationship is not proven to be causative and future studies should opt for longitudinal designs with consistent methodological approaches, as well as adequate techniques for analysing and reporting the results.

IL-36γ and IL-36Ra Reciprocally Regulate Colon Inflammation and Tumorigenesis by Modulating the Cell-Matrix Adhesion Network and Wnt Signaling

Inflammatory bowel disease and colorectal cancer are associated with dysregulation of cytokine networks. However, it is challenging to target cytokines for effective intervention because of the overlapping functions and unpredictable interactions of cytokines in such diverse networks. Here, it is shown that IL-36γ and IL-36Ra, an agonist and an antagonist for IL-36R signaling respectively, reciprocally regulate the experimental colitis and the colon cancer development in mice. Knockout or neutralization of IL-36γ alleviates dextran sulfate sodium (DSS)-induced colitis and inhibits colon cancer development, whereas knockout of IL-36Ra exacerbates DSS-induced colitis and promotes colonic tumorigenesis in multiple colon cancer models in mice. Mechanistically, IL-36γ upregulates extracellular matrix and cell-matrix adhesion molecules and facilitates Wnt signaling, which is mitigated by IL-36Ra or IL-36γ neutralizing antibody. Consistently, IL-36γ levels are positively correlated with extracellular matrix levels and β-catenin levels in human colorectal tumor biopsies. These findings suggest the critical role of IL-36γ and IL-36Ra in gut inflammation and tumorigenesis and indicate that targeting the IL-36γ/IL-36Ra signal balance provides potential therapeutic strategy for inflammatory bowel disease and gastrointestinal cancers.

Cytokines and Chemokines in Cancer Cachexia and Its Long-Term Impact on COVID-19

Cancer cachexia remains a serious public health concern worldwide, particularly as cancer rates rise. Treatment is endangered, and survival is reduced, because this illness is commonly misdiagnosed and undertreated. Although weight loss is the most evident sign of cachexia, there are other early metabolic and inflammatory changes that occur before the most obvious symptoms appear. Cachexia-related inflammation is induced by a combination of factors, one of which is the release of inflammation-promoting chemicals by the tumor. Today, more scientists are beginning to believe that the development of SARS-CoV-2 (COVID-19) related cachexia is similar to cancer-related cachexia. It is worth noting that patients infected with COVID-19 have a significant inflammatory response and can develop cachexia. These correlations provide feasible reasons for the variance in the occurrence and severity of cachexia in human malignancies, therefore, specific therapeutic options for these individuals must be addressed based on disease types. In this review, we highlighted the role of key chemokines, cytokines, and clinical management in relation to cancer cachexia and its long-term impact on COVID-19 patients.

Amelioration of cancer cachexia with preemptive administration of tumor necrosis factor-α blocker

Cancer cachexia is syndrome accompanying weight reduction, fat loss, muscle atrophy in patients with advanced cancer. Since tumor necrosis factor-α (TNF-α) played pivotal role in cancer cachexia, we hypothesized preemptive administration of TNF-α antibody might mitigate cancer cachexia. Detailed molecular mechanisms targeting muscle atrophy, cachexic inflammation, and catabolic catastrophe were explored whether TNF-α antibody can antagonize these cachexic mechanisms. Stimulated with preliminary finding human antibody, infliximab or adalimumab, significantly inhibited TNF-α as well as their signals relevant to cachexia in mice, preemptive administration of 1.5 mg/kg adalimumab was done in C-26-induced cancer cachexia. Adalimumab significantly mitigated cancer cachexia manifested with significantly lesser weight loss, leg muscle preservation, and higher survival compared to cachexia control (p<0.05). Significant ameliorating action of muscle atrophy were accompanied significant decreases of muscle-specific UPS like atrogin-1/MuRF-1, Pax-7, PCG-1α, and Mfn-2 after adalimumab (p<0.01) and significantly attenuated lipolysis with inhibition of ATGL HSL, and MMPs. Cachexic factors including IL-6 expression, serum IL-6, gp130, IL-6R, JAK2, and STAT3 were significantly inhibited with adalimumab (p<0.01). Genes implicated in cachexic inflammation like NF-κB, c-Jun/c-Fos, and MAPKs were significantly repressed, while mTOR/AKT was significantly increased adalimumab (p<0.05). Conclusively, preemptive administration of adalimumab can be tried in high risk to cancer cachexia.

Revisiting Cancer Cachexia: Pathogenesis, Diagnosis, and Current Treatment Approaches

The objective of this article is to group together various management strategies and to highlight the recent treatment modifications that attempt to target the multimodal etiological factors involved in cancer cachexia. The contemporary role of nursing fraternity in psychosocial and nutritional assessment of cancer patients is briefly discussed. Cachexia is a syndrome of metabolic disturbance, characterized by the inflammation and loss of muscle with or without loss of adipose tissue. In cancer cachexia, a multifaceted condition, patients suffer from loss of body weight that leads to a negative impact on the quality of life and survival of the patients. The main cancers associated with cachexia are that of pancreas, stomach, lung, esophagus, liver, and that of bowel. The changes include increased proteolysis, lipolysis, insulin resistance, high energy expenditure, and reduced intake of food, all leading to impaired response to different treatments. There is no standardized treatment for cancer cachexia that can stabilize or reverse this complex metabolic disorder at present. The mainstay of cancer cachexia therapy remains to be sufficient nutritional supplements with on-going efforts to explore the drugs that target heightened catabolic processes and complex inflammation. There is a need to develop a multimodal treatment approach combining pharmacology, exercise program, and nutritional support to target anorexia and the severe metabolic changes encountered in cancer cachexia.

Neural Mechanisms of Cancer Cachexia

Simple Summary

Cancer cachexia is a devastating wasting syndrome that occurs in many illnesses, with signs and symptoms including anorexia, weight loss, cognitive impairment and fatigue. The brain is capable of exerting overarching homeostatic control of whole-body metabolism and is increasingly being recognized as an important mediator of cancer cachexia. Given the increased recognition and discovery of neural mechanisms of cancer cachexia, we sought to provide an in-depth review and update of mechanisms by which the brain initiates and propagates cancer cachexia programs. Furthermore, recent work has identified new molecular mediators of cachexia that exert their effects through their direct interaction with the brain. Therefore, this review will summarize neural mechanisms of cachexia and discuss recently identified neural mediators of cancer cachexia.

Abstract

Nearly half of cancer patients suffer from cachexia, a metabolic syndrome characterized by progressive atrophy of fat and lean body mass. This state of excess catabolism decreases quality of life, ability to tolerate treatment and eventual survival, yet no effective therapies exist. Although the central nervous system (CNS) orchestrates several manifestations of cachexia, the precise mechanisms of neural dysfunction during cachexia are still being unveiled. Herein, we summarize the cellular and molecular mechanisms of CNS dysfunction during cancer cachexia with a focus on inflammatory, autonomic and neuroendocrine processes and end with a discussion of recently identified CNS mediators of cachexia, including GDF15, LCN2 and INSL3.

Activated mast cells in skeletal muscle can be a potential mediator for cancer-associated cachexia

BACKGROUND

Eighty per cent of United States advanced cancer patients faces a worsened prognosis due to cancer-associated cachexia. Inflammation is one driver of muscle atrophy in cachexia, and skeletal muscle-resident immune cells could be a source of inflammation. This study explores the efficacy of cancer activated skeletal muscle-resident mast cells as a biomarker and mediator of cachexia.

METHODS

Individual gene markers for immune cells were assessed in a publicly available colon carcinoma cohort of normal (n = 3), moderate cachexia (n = 3), and severe cachexia (n = 4) mice. Lewis lung carcinoma (LL/2) cells induced cachexia in C57BL/6 mice, and a combination of toluidine blue staining, immunofluorescence, quantitative polymerase chain reaction, and western blots measured innate immune cell expression in hind limb muscles. In vitro measurements included C2C12 myotube diameter before and after treatment with media from primary murine mast cells activated with LL/2 conditioned media. To assess translational potential in human samples, innate immune cell signatures were assessed for correlation with skeletal muscle atrophy and apoptosis, dietary excess, and cachexia signatures in normal skeletal muscle tissue. Gene set enrichment analysis was performed with innate immune cell signatures in publicly available cohorts for upper gastrointestinal (GI) cancer and pancreatic ductal adenocarcinoma (PDAC) patients (accession: GSE34111 and GSE130563, respectively).

RESULTS

Individual innate immunity genes (TPSAB1 and CD68) showed significant increases in severe cachexia (weight loss > 15%) mice in a C26 cohort (GSE24112). Induction of cachexia in C57BL/6 mice with LL/2 subcutaneous injection significantly increased the number of activated skeletal muscle-resident degranulating mast cells. Murine mast cells activated with LL/2 conditioned media decreased C2C12 myotube diameter (P ≤ 0.05). Normal human skeletal muscle showed significant positive correlations between innate immune cell signatures and muscle apoptosis and atrophy, dietary excess, and cachexia signatures. The mast cell signature was up-regulated (positive normalized enrichment score and false discovery rate ≤ 0.1) in upper GI cachectic patients (n = 12) compared with control (n = 6), as well as in cachectic PDAC patients (n = 17) compared with control patients (n = 16).

CONCLUSIONS

Activated skeletal muscle-resident mast cells are enriched in cachectic muscles, suggesting skeletal-muscle resident mast cells may serve as a biomarker and mediator for cachexia development to improve patient diagnosis and prognosis.

Repurposing of Antibiotic Sulfisoxazole Inhibits Lipolysis in Pre-Clinical Model of Cancer-Associated Cachexia

Clinical management of cancer-associated cachexia, a multi-organ wasting syndrome, has been challenging without effective treatment strategies. An effective treatment that directly targets cancer-induced wasting is desperately needed to improve the quality of life and the survival of cancer patients. Recently, an antibiotic SFX was shown to have anti-tumour and anti-metastatic effects in mouse models of breast cancer. Hence, in this study, we examined the efficacy of SFX in the treatment of cancer-induced cachexia. C26 cachexic mice models were administered with SFX, and the tumour volume and body weight were regularly measured. Blood glucose, skeletal muscles, and adipose tissue were examined at the endpoint. Contrary to a previous study, SFX did not reduce the tumour volume in mice bearing C26 cells. Administration of SFX neither revealed any survival benefit nor rescued C26 cachectic mice from muscle wasting. Interestingly, SFX administration partially rescued (~10%) tumour-induced weight loss by preserving both the subcutaneous and intestinal fat mass. Together, these results suggest that the administration of SFX could partially rescue cancer-induced weight loss by inhibiting lipolysis. As anti-cachexia therapies are scarce, the results could facilitate the design of combinatorial therapies involving SFX, standard-of-care chemotherapeutics, and drugs that inhibit muscle atrophy for the treatment of cancer cachexia.

Pharmacological or genetic inhibition of iNOS prevents cachexia-mediated muscle wasting and its associated metabolism defects

Cachexia syndrome develops in patients with diseases such as cancer and sepsis and is characterized by progressive muscle wasting. While iNOS is one of the main effectors of cachexia, its mechanism of action and whether it could be targeted for therapy remains unexplored. Here, we show that iNOS knockout mice and mice treated with the clinically tested iNOS inhibitor GW274150 are protected against muscle wasting in models of both septic and cancer cachexia. We demonstrate that iNOS triggers muscle wasting by disrupting mitochondrial content, morphology, and energy production processes such as the TCA cycle and acylcarnitine transport. Notably, iNOS inhibits oxidative phosphorylation through impairment of complexes II and IV of the electron transport chain and reduces ATP production, leading to energetic stress, activation of AMPK, suppression of mTOR, and, ultimately, muscle atrophy. Importantly, all these effects were reversed by GW274150. Therefore, our data establish how iNOS induces muscle wasting under cachectic conditions and provide a proof of principle for the repurposing of iNOS inhibitors, such as GW274150 for the treatment of cachexia.

Cell-based immunotherapy approaches for colorectal cancer: main achievements and challenges

Immunotherapy is becoming as a major treatment modality for multiple types of solid tumors, including subsets of colorectal cancers (CRCs). The successes with immunotherapy alone has largely been achieved in patients with advanced-stage mismatch-repair-deficient and microsatellite instability-high (dMMR-MSI-H) CRCs. However, the benefits of immunotherapy have not been demonstrated to be effective in patients with proficient mismatch repair (pMMR) CRC, who are microsatellite-stable (MSS) or have low levels of microsatellite instability (MSI-L). Here, we provide a comprehensive review on the immune microenvironment of CRC tumors and describe the rapid pace of scientific changes. We discuss the tremendous promise of cell-based immunotherapy strategies that are under preclinical studies/clinical trials or being used in therapeutic paradigms.

Aberrant NLRP3 Inflammasome Activation Ignites the Fire of Inflammation in Neuromuscular Diseases

Inflammasomes are molecular hubs that are assembled and activated by a host in response to various microbial and non-microbial stimuli and play a pivotal role in maintaining tissue homeostasis. The NLRP3 is a highly promiscuous inflammasome that is activated by a wide variety of sterile triggers, including misfolded protein aggregates, and drives chronic inflammation via caspase-1-mediated proteolytic cleavage and secretion of proinflammatory cytokines, interleukin-1β and interleukin-18. These cytokines further amplify inflammatory responses by activating various signaling cascades, leading to the recruitment of immune cells and overproduction of proinflammatory cytokines and chemokines, resulting in a vicious cycle of chronic inflammation and tissue damage. Neuromuscular diseases are a heterogeneous group of muscle disorders that involve injury or dysfunction of peripheral nerves, neuromuscular junctions and muscles. A growing body of evidence suggests that dysregulation, impairment or aberrant NLRP3 inflammasome signaling leads to the initiation and exacerbation of pathological processes associated with neuromuscular diseases. In this review, we summarize the available knowledge about the NLRP3 inflammasome in neuromuscular diseases that affect the peripheral nervous system and amyotrophic lateral sclerosis, which affects the central nervous system. In addition, we also examine whether therapeutic targeting of the NLRP3 inflammasome components is a viable approach to alleviating the detrimental phenotype of neuromuscular diseases and improving clinical outcomes.

Cancer-Mediated Muscle Cachexia: Etiology and Clinical Management

Muscle cachexia has a major detrimental impact on cancer patients, being responsible for 30% of all cancer deaths. It is characterized by a debilitating loss in muscle mass and function, which ultimately deteriorates patients' quality of life and dampens therapeutic treatment efficacy. Muscle cachexia stems from widespread alterations in whole-body metabolism as well as immunity and neuroendocrine functions and these global defects often culminate in aberrant signaling within skeletal muscle, causing muscle protein breakdown and attendant muscle atrophy. This review summarizes recent landmark discoveries that significantly enhance our understanding of the molecular etiology of cancer-driven muscle cachexia and further discuss emerging therapeutic approaches seeking to simultaneously target those newly discovered mechanisms to efficiently curb this lethal syndrome.

A multimodal approach to cancer-related cachexia: from theory to practice

Introduction: Cachexia represents a relevant issue in oncological care, which is still lacking effective therapies. Although the incidence of cancer cachexia varies across cancer types, it is responsible for approximately a quarter of cancer-related deaths. The pathophysiology of this syndrome is multifactorial, including weight loss, muscle atrophy and impairment of the pro-/anti-inflammatory balance.Areas covered: Diagnostic criteria and optimal endpoints for cachexia-dedicated trials are still debated, slowing the identification of interventions counteracting cachexia sequaele. The multifaceted features of this syndrome support the rationale for personalized therapy. A multimodal approach is likely to offer the best option to address key cachexia-related issues. Pharmacologic agents, physical exercise, nutritional and psycho-social interventions may have a synergistic effect, and improve quality of life.Expert opinion: A personalized multimodal intervention could be the best strategy to effectively manage cancer cachexia. To offer such a comprehensive approach, a specialized staff, including health professionals with different expertise, is necessary. Each specialist plays a specific role inside the multimodal intervention, with the aim of delivering the best cancer care and access to the most effective therapeutic options for each patient.

Inflammation and Skeletal Muscle Wasting During Cachexia

Cachexia is the involuntary loss of muscle and adipose tissue that strongly affects mortality and treatment efficacy in patients with cancer or chronic inflammatory disease. Currently, no specific treatments or interventions are available for patients developing this disorder. Given the well-documented involvement of pro-inflammatory cytokines in muscle and fat metabolism in physiological responses and in the pathophysiology of chronic inflammatory disease and cancer, considerable interest has revolved around their role in mediating cachexia. This has been supported by association studies that report increased levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in some, but not all, cancers and in chronic inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and rheumatoid arthritis (RA). In addition, preclinical studies including animal disease models have provided a substantial body of evidence implicating a causal contribution of systemic inflammation to cachexia. The presence of inflammatory cytokines can affect skeletal muscle through several direct mechanisms, relying on activation of the corresponding receptor expressed by muscle, and resulting in inhibition of muscle protein synthesis (MPS), elevation of catabolic activity through the ubiquitin-proteasomal system (UPS) and autophagy, and impairment of myogenesis. Additionally, systemic inflammatory mediators indirectly contribute to muscle wasting through dysregulation of tissue and organ systems, including GCs via the hypothalamus-pituitary-adrenal (HPA) axis, the digestive system leading to anorexia-cachexia, and alterations in liver and adipocyte behavior, which subsequently impact on muscle. Finally, myokines secreted by skeletal muscle itself in response to inflammation have been implicated as autocrine and endocrine mediators of cachexia, as well as potential modulators of this debilitating condition. While inflammation has been shown to play a pivotal role in cachexia development, further understanding how these cytokines contribute to disease progression is required to reveal biomarkers or diagnostic tools to help identify at risk patients, or enable the design of targeted therapies to prevent or delay the progression of cachexia.

Exploiting common aspects of obesity and cancer cachexia for future therapeutic strategies

Obesity and cancer cachexia are diseases at opposite ends of the BMI. However, despite the apparent dichotomy, these pathologies share some common underlying mechanisms that lead to profound metabolic perturbations. Insulin resistance, adipose tissue lipolysis, skeletal muscle atrophy and systemic inflammation are key players in both diseases. Several strategies for pharmacological treatments have been employed in obesity and cancer cachexia but demonstrated only limited effects. Therefore, there is still a need to develop novel, more effective strategies. In this review we summarize existing therapies and discuss potential novel strategies that could arise by bridging common aspects between obesity and cachexia. We discuss the potential role of macrophage manipulation and the modulation of inflammation by targeting Nuclear Receptors (NRs) as potential novel therapeutic strategies.

The clinical relevance and mechanism of skeletal muscle wasting

Skeletal muscle wasting occurs in both chronic and acute diseases. Increasing evidence has shown this debilitating process is associated with short- and long-term outcomes in critical, cancer and surgical patients. Both muscle quantity and quality, as reflected by the area and density of a given range of attenuation in CT scan, impact the patient prognosis. In addition, ultrasound and bioelectrical impedance analysis (BIA) are also widely used in the assessment of body composition due to their bedside viability and no radioactivity. Mechanism researches have revealed complicated pathways are involved in muscle wasting, which include altered IGF1-Akt-FoxO signaling, elevated levels of myostatin and activin A, activation of NF-κB pathway and glucocorticoid effects. Particularly, central nervous system (CNS) has been proven to participate in regulating muscle wasting in various conditions, such as infection and tumor. Several promising therapeutic agents have been under developing in the treatment of muscle atrophy, such as myostatin antagonist, ghrelin analog, non-steroidal selective androgen receptor modulators (SARMs). Notably, nutritional therapy is still the fundamental support in combating muscle wasting. However, the optimizing and tailored nutrition regimen relies on accurate metabolism measurement and large clinical trials in the future. Here, we will discuss the current understanding of muscle wasting and potential treatment in clinical practice.

Mitochondrial dysfunction/NLRP3 inflammasome axis contributes to angiotensin II-induced skeletal muscle wasting via PPAR-γ

Angiotensin II (Ang II) levels are elevated in patients with chronic kidney disease or heart failure, and directly causes skeletal muscle wasting in rodents, but the molecular mechanisms of Ang II-induced skeletal muscle wasting and its potential as a therapeutic target are unknown. We investigated the NLR family pyrin domain containing 3 (NLRP3) inflammasome-mediated muscle atrophy response to Ang II in C2C12 myotubes and Nlrp3 knockout mice. We also assessed the mitochondrial dysfunction (MtD)/NLRP3 inflammasome axis in Ang II-induced C2C12 myotubes. Finally, we examined whether a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist could attenuate skeletal muscle wasting by targeting the MtD/NLRP3 inflammasome axis in vitro and in vivo. We demonstrated that Ang II increased NLRP3 inflammasome activation in cultured C2C12 myotubes dose dependently. Nlrp3 knockdown or Nlrp3^-/- mice were protected from the imbalance of protein synthesis and degradation. Exposure of C2C12 to Ang II increased mitochondrial ROS (mtROS) generation, accompanied by MtD. Remarkably, the mitochondrial-targeted antioxidant not only decreased mtROS and MtD, it also significantly inhibited NLRP3 inflammasome activation and restored skeletal muscle atrophy. Finally, the PPAR-γ agonist protected against Ang II-induced muscle wasting by preventing MtD, oxidative stress, and NLRP3 inflammasome activation in vitro and in vivo. This work suggests a potential role of MtD/NLRP3 inflammasome pathway in the pathogenesis of Ang II-induced skeletal muscle wasting, and targeting the PPAR-γ/MtD/NLRP3 inflammasome axis may provide a therapeutic approach for muscle wasting.

Management of Cancer Cachexia: Attempting to Develop New Pharmacological Agents for New Effective Therapeutic Options

Cancer cachexia (CC) is a multifactorial syndrome characterized by systemic inflammation, uncontrolled weight loss and dramatic metabolic alterations. This includes myofibrillar protein breakdown, increased lipolysis, insulin resistance, elevated energy expediture, and reduced food intake, hence impairing the patient's response to anti-cancer therapies and quality of life. While a decade ago the syndrome was considered incurable, over the most recent years much efforts have been put into the study of such disease, leading to the development of potential therapeutic strategies. Several important improvements have been reached in the management of CC from both the diagnostic-prognostic and the pharmacological viewpoint. However, given the heterogeneity of the disease, it is impossible to rely only on single variables to properly treat patients presenting this metabolic syndrome. Moreover, the cachexia symptoms are strictly dependent on the type of tumor, stage and the specific patient's response to cancer therapy. Thus, the attempt to translate experimentally effective therapies into the clinical practice results in a great challenge. For this reason, it is of crucial importance to further improve our understanding on the interplay of molecular mechanisms implicated in the onset and progression of CC, giving the opportunity to develop new effective, safe pharmacological treatments. In this review we outline the recent knowledge regarding cachexia mediators and pathways involved in skeletal muscle (SM) and adipose tissue (AT) loss, mainly from the experimental cachexia standpoint, then retracing the unimodal treatment options that have been developed to the present day.

Understanding the Role of Exercise in Cancer Cachexia Therapy

Cachexia, the unintentional loss of body weight, is prevalent in many cancer types, and the associated skeletal muscle mass depletion increases patient morbidity and mortality. While anorexia can be present, cachexia is not reversible with nutritional therapies alone. Pharmacological agents have been proposed to treat this condition, but there are currently no approved treatments. Nonetheless, the hallmark characteristics associated with cancer cachexia remain viable foundations for future therapies. Regular physical activity holds a promising future as a nonpharmacological alternative to improve patient survival through cachexia prevention. Evidence suggests exercise training is beneficial during cancer treatment and survival. However, the mechanistic examination of cachectic skeletal muscle's response to exercise is both needed and justified. The primary objective of this review is to discuss the role of exercise for the prevention and treatment of cancer-associated muscle wasting. Initially, we provide an overview of systemic alterations induced by cancer and their role in the regulation of wasting processes during cachexia progression. We then discuss how exercise could alter disrupted regulatory pathways related to growth and metabolism during cancer-induced muscle atrophy. Last, we outline current exercise prescription guidelines and how exercise could be a potential behavioral therapy to curtail cachexia development in cancer patients.

Molecular therapeutic strategies targeting pancreatic cancer induced cachexia

Pancreatic cancer (PC) induced cachexia is a complex metabolic syndrome associated with significantly increased morbidity and mortality and reduced quality of life. The pathophysiology of cachexia is complex and poorly understood. Many molecular signaling pathways are involved in PC and cachexia. Though our understanding of cancer cachexia is growing, therapeutic options remain limited. Thus, further discovery and investigation of the molecular signaling pathways involved in the pathophysiology of cachexia can be applied to development of targeted therapies. This review focuses on three main pathophysiologic processes implicated in the development and progression of cachexia in PC, as well as their utility in the discovery of novel targeted therapies.

Skeletal muscle wasting is the most prominent pathophysiologic anomaly in cachectic patients and driven by multiple regulatory pathways. Several known molecular pathways that mediate muscle wasting and cachexia include transforming growth factor-beta (TGF-β), myostatin and activin, IGF-1/PI3K/AKT, and JAK-STAT signaling. TGF-β antagonism in cachectic mice reduces skeletal muscle catabolism and weight loss, while improving overall survival. Myostatin/activin inhibition has a great therapeutic potential since it plays an essential role in skeletal muscle regulation. Overexpression of insulin-like growth factor binding protein-3 (IGFBP-3) leads to increased ubiquitination associated proteolysis, inhibition of myogenesis, and decreased muscle mass in PC induced cachexia. IGFBP-3 antagonism alleviates muscle cell wasting.

Another component of cachexia is profound systemic inflammation driven by pro-cachectic cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon gamma (INF-γ). IL-6 antagonism has been shown to reduce inflammation, reduce skeletal muscle loss, and ameliorate cachexia. While TNF-α inhibitors are clinically available, blocking TNF-α signaling is not effective in the treatment of cancer cachexia. Blocking the synthesis or action of acute phase reactants and cytokines is a feasible therapeutic strategy, but no anti-cytokine therapies are currently approved for use in PC. Metabolic alterations such as increased energy expenditure and gluconeogenesis, insulin resistance, fat tissue browning, excessive oxidative stress, and proteolysis with amino acid mobilization support tumor growth and the development of cachexia. Current innovative nutritional strategies for cachexia management include ketogenic diet, utilization of natural compounds such as silibinin, and supplementation with ω3-polyunsaturated fatty acids. Elevated ketone bodies exhibit an anticancer and anticachectic effect. Silibinin has been shown to inhibit growth of PC cells, induce metabolic alterations, and reduce myofiber degradation. Consumption of ω3-polyunsaturated fatty acids has been shown to significantly decrease resting energy expenditure and regulate metabolic dysfunction.

Pharmacological management of cachexia in adult cancer patients: a systematic review of clinical trials

Background

Cachexia is a multisystem syndrome characterized by weight loss, anorexia, loss of muscle mass, systemic inflammation, insulin resistance, and functional decline. Management of cachexia involves addressing multiple underlying biological mechanisms. Previous review on pharmacological management of cancer cachexia identified progestins and corticosteroids as effective agents for treatment of cachexia. However, to date no consensus exists on a single effective or standard treatment for management of cachexia. The aim of this systematic review is to determine the effectiveness of pharmacological treatments used to manage cachexia among adult cancer patients.

Methods

We performed literature searches of PubMed (NLM), Embase (Ovid), and Medline(Ovid) to identify clinical trials focused on pharmacological management of cancer cachexia among adult cancer patients from 2004 to 2018. Three reviewers screened a random selection of abstracts to measure for interrater reliability. After this step, each screener screened two-thirds of all abstracts and 177 studies were identified for full text review. The primary outcome was impact of pharmacological management on change in either weight or lean body mass in cancer patients.

Results

We identified 19 articles (representing 20 RCTs) that focused on pharmacological management of cancer cachexia. Agents showing promising results included Anamorelin and Enobosarm. Anamorelin at 50 or 100 mg per day for 12 weeks showed a consistent benefit across all studies and resulted in significant improvement in weight as compared to baseline among cancer patients. Enobosarm at 1 and 3 mg per day was also effective in improving lean body mass and QOL symptoms among advancer stage cancer patients. Finally, use of combination agents provide evidence for targeting multiple pathways underlying cachexia mechanism to achieve maximum benefit. No agents showed functional improvement in cancer patients.

Conclusion

Anamorelin as a single agent shows promising results in improving cachexia related weight loss among cancer patients. Further research on combination therapies may be helpful to address critical gaps in cachexia management.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5080-4) contains supplementary material, which is available to authorized users.

The phosphatidic acid phosphatase lipin-1 facilitates inflammation-driven colon carcinogenesis

Colon cancer is a devastating illness that is associated with gut inflammation. Here, we explored the possible role of lipin-1, a phosphatidic acid phosphatase, in the development of colitis-associated tumorigenesis. Azoxymethane and dextran sodium sulfate-treated (DSS-treated) animals deficient in lipin-1 harbored fewer tumors and carcinomas than WT animals due to decreased cellular proliferation, lower expression of antiapoptotic and protumorigenic factors, and a reduced infiltration of macrophages in colon tumors. They also displayed increased resistance to DSS-induced colitis by producing less proinflammatory cytokines and experiencing less immune infiltration. Lipin-1-deficient macrophages from the colon were less activated and displayed lower phosphatidic acid phosphatase activity than WT macrophages isolated from DSS-treated animals. Transference of WT macrophages into lipin-1-deficient animals was sufficient to increase colitis burden. Furthermore, treatment of lipin-1-deficient mice with IL-23 exacerbated colon inflammation. Analysis of human databases from colon cancer and ulcerative colitis patients showed that lipin-1 expression is increased in those disorders and correlates with the expression of the proinflammatory markers CXCL1 and CXCL2. And finally, clinically, LPIN1 expression had prognostic value in inflammatory and stem-cell subtypes of colon cancers. Collectively, these data demonstrate that lipin-1 is a critical regulator of intestinal inflammation and inflammation-driven colon cancer development.

The Role of Systemic Inflammation in Cancer-Associated Muscle Wasting and Rationale for Exercise as a Therapeutic Intervention

Progressive skeletal muscle wasting in cancer cachexia involves a process of dysregulated protein synthesis and breakdown.  This catabolism may be the result of mal-nutrition, and an upregulation of both pro-inflammatory cytokines and the ubiquitin proteasome pathway (UPP), which can subsequently increase myostatin and activin A release.  The skeletal muscle wasting associated with cancer cachexia is clinically significant, it can contribute to treatment toxicity or the premature discontinuation of treatments resulting in increases in morbidity and mortality.  Thus, there is a need for further investigation into the pathophysiology of muscle wasting in cancer cachexia to develop effective prophylactic and therapeutic interventions.  Several studies have identified a central role for chronic-systemic inflammation in initiating and perpetuating muscle wasting in patients with cancer.  Interestingly, while exercise has shown efficacy in improving muscle quality, only recently have investigators begun to assess the impact that exercise has on chronic-systemic inflammation.  To put this new information into context with established paradigms, here we review several biological pathways (e.g. dysfunctional inflammatory response, hypothalamus pituitary adrenal axis, and increased myostatin/activin A activity) that may be responsible for the muscle wasting in patients with cancer.  Additionally, we discuss the potential impact that exercise has on these pathways in the treatment of cancer cachexia.  Exercise is an attractive intervention for muscle wasting in this population, partially because it disrupts chronic-systemic inflammation mediated catabolism.  Most importantly, exercise is a potent stimulator of muscle synthesis, and therefore this therapy may reverse muscle damage caused by cancer cachexia. 

Muscle Wasting Diseases: Novel Targets and Treatments

Adequate skeletal muscle plasticity is an essential element for our well-being, and compromised muscle function can drastically affect quality of life, morbidity, and mortality. Surprisingly, however, skeletal muscle remains one of the most under-medicated organs. Interventions in muscle diseases are scarce, not only in neuromuscular dystrophies, but also in highly prevalent secondary wasting pathologies such as sarcopenia and cachexia. Even in other diseases that exhibit a well-established risk correlation of muscle dysfunction due to a sedentary lifestyle, such as type 2 diabetes or cardiovascular pathologies, current treatments are mostly targeted on non-muscle tissues. In recent years, a renewed focus on skeletal muscle has led to the discovery of various novel drug targets and the design of new pharmacological approaches. This review provides an overview of the current knowledge of the key mechanisms involved in muscle wasting conditions and novel pharmacological avenues that could ameliorate muscle diseases.

1α,25-dihydroxyvitamin D3 mitigates cancer cell mediated mitochondrial dysfunction in human skeletal muscle cells

Cancer cachexia is associated with muscle weakness and atrophy. We investigated whether 1α,25-dihydroxyvitamin D₃ (1α,25(OH)₂D₃), which has previously been shown to increase skeletal myoblast oxygen consumption rate, could reverse the deleterious effects of tumor cell conditioned medium on myoblast function. Conditioned medium from Lewis lung carcinoma (LLC1) cells inhibits oxygen consumption, increases mitochondrial fragmentation, inhibits pyruvate dehydrogenase activity, and enhances proteasomal activity in human skeletal muscle myoblasts. 1α,25(OH)₂D₃ reverses the tumor cell-mediated changes in mitochondrial oxygen consumption and proteasomal activity, without changing pyruvate dehydrogenase activity. 1α,25(OH)₂D₃ might be useful in treatment of weakness seen in association with CC.

Circulating inflammatory factors associated with worse long-term prognosis in colorectal cancer

AIM

To investigate association of circulating inflammatory factors at the time of colorectal cancer (CRC) surgery with survival.

METHODS

Plasma levels from 174 CRC patients (69 females and 105 men), with median age 70 years (range 29-90), localized in the colon (n = 105) or rectum (n = 69), with stage I (n = 24), stage II (n = 54), stage III (n = 67) and stage IV (n = 29) were measured using commercially available Bio-Plex Pro™ Human Chemokine Panel 40-Plex, including 40 different chemokines, cytokines and interleukins. The prognostic association of each inflammatory factor was analysed as CRC-specific and total mortality.

RESULTS

Out of 174 patients, 66 died during the follow-up, 40 because of CRC specific mortality. High tertile levels of 8 factors were significantly associated with increased CRC-specific mortality, of which CCL1, CCL20, CCL24, CX3CL1, IL-4 and TNF-α remained significant in a multivariate Cox regression analysis. High tertile levels of 14 factors were associated with increased total mortality, of which CCL1, CCL15, CCL20, CX3CL1, CXCL13, IFN-γ, IL-2, IL-4 and IL-10 remained significant after adjustment for clinical covariates. For most of the inflammatory factors the association between higher tertile levels and an increased mortality in general appeared two years after surgery. High tertile levels of TNF-α and CCL24 were exclusively associated with CRC-specific mortality. The distribution of these factors were not associated with TNM stage with exception for CCL20.

CONCLUSION

High plasma levels of inflammatory factors are associated with increased risk of mortality among CRC patients and could be potential biomarkers for revealing prognosis.

Loss of dual-specificity phosphatase-2 promotes angiogenesis and metastasis via up-regulation of interleukin-8 in colon cancer

Dual-specificity phosphatase 2 (DUSP2) is a negative regulator of mitogen-activated protein kinases. Our previous study showed that DUSP2 expression is down-regulated in many human cancers and loss of DUSP2 promotes cancer progression; however, the underlying mechanism remains largely uncharacterized. Herein, we found that loss of DUSP2 induces angiogenesis, while forced expression of DUSP2 inhibits microvessel formation in xenografted mouse tumours. Genome-wide screening of expression profiles, and meta-analysis of clinical data, identified that the level of interleukin-8 (IL-8) correlated negatively with that of DUSP2, suggesting that it may be a downstream target of DUSP2. Molecular characterization revealed that DUSP2 inversely regulates IL-8 expression, mediated by ERK1/2 and C/EBPα-dependent transcriptional regulation. Further study showed that hypoxia-induced IL-8 expression in cancer cells is also mediated via down-regulation of DUSP2. Treatment with the IL-8 receptor inhibitor reparixin or knockdown of IL-8 in cancer cells abolished angiogenesis induced by loss of DUSP2. Functionally, knockdown of DUSP2 enhanced tumour growth and metastasis, which were abolished by treatment with reparixin or knockdown of IL-8 in an orthotopic mouse model. Taken together, our results demonstrate that hypoxia inhibits DUSP2 expression in colon cancer, leading to up-regulation of IL-8, which facilitates angiogenesis and tumour metastasis. Our findings suggest that blocking hypoxia-DUSP2-IL-8 signalling may be a plausible approach for therapeutic intervention in cancer. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.