Plasma growth differentiation factor 15 is associated with weight loss and mortality in cancer patients

Activin A-Induced Cachectic Wasting Is Attenuated by Systemic Delivery of Its Cognate Propeptide in Male Mice

In cancer, elevated activin levels promote cachectic wasting of muscle, irrespective of tumor progression. In excess, activins A and B use the myostatin signaling pathway in muscle, triggering a decrease in protein synthesis and an increase in protein degradation, which ultimately leads to atrophy. Recently, we demonstrated that local delivery of engineered activin and myostatin propeptides (natural inhibitors of these growth factors) could induce profound muscle hypertrophy in healthy mice. Additionally, the expression of these propeptides effectively attenuated localized muscle wasting in models of dystrophy and cancer cachexia. In this study, we examined whether a systemically administered recombinant propeptide could reverse activin A-induced cachectic wasting in mice. Chinese hamster ovary cells stably expressing activin A were transplanted into the quadriceps of nude mice and caused an 85-fold increase in circulating activin A levels within 12 days. Elevated activin A induced a rapid reduction in body mass (-16%) and lean mass (-10%). In agreement with previous findings, we demonstrated that adeno-associated virus-mediated delivery of activin propeptide to the tibialis anterior muscle blocked activin-induced wasting. In addition, despite massively elevated levels of activin A in this model, systemic delivery of the propeptide significantly reduced activin-induced changes in lean and body mass. Specifically, recombinant propeptide reversed activin-induced wasting of skeletal muscle, heart, liver, and kidneys. This is the first study to demonstrate that systemic administration of recombinant propeptide therapy effectively attenuates tumor-derived activin A insult in multiple tissues.

Nausea and vomiting of pregnancy and hyperemesis gravidarum

Nausea and vomiting of pregnancy (NVP) is a common condition that affects as many as 70% of pregnant women. Although no consensus definition is available for hyperemesis gravidarum (HG), it is typically viewed as the severe form of NVP and has been reported to occur in 0.3-10.8% of pregnant women. HG can be associated with poor maternal, fetal and child outcomes. The majority of women with NVP can be managed with dietary and lifestyle changes, but more than one-third of patients experience clinically relevant symptoms that may require fluid and vitamin supplementation and/or antiemetic therapy such as, for example, combined doxylamine/pyridoxine, which is not teratogenic and may be effective in treating NVP. Ondansetron is commonly used to treat HG, but studies are urgently needed to determine whether it is safer and more effective than using first-line antiemetics. Thiamine (vitamin B1) should be introduced following protocols to prevent refeeding syndrome and Wernicke encephalopathy. Recent advances in the genetic study of NVP and HG suggest a placental component to the aetiology by implicating common variants in genes encoding placental proteins (namely GDF15 and IGFBP7) and hormone receptors (namely GFRAL and PGR). New studies on aetiology, diagnosis, management and treatment are under way. In the next decade, progress in these areas may improve maternal quality of life and limit the adverse outcomes associated with HG.

Targeting the divergent TGFβ superfamily cytokine MIC-1/GDF15 for therapy of anorexia/cachexia syndromes

PURPOSE OF REVIEW

To review recent finding on MIC-1/GDF15 and re-evaluate it as a potential target for the therapy of anorexia/cachexia syndromes.

RECENT FINDINGS

MIC-1/GDF15 consistently induces anorexia/cachexia in animal models. Its actions on brainstem feeding centers leads to anorexia, inducing prolonged undernutrition and consequent loss of both lean and fat mass. Epidemiological studies by multiple groups have linked substantially elevated serum levels of this cytokine to anorexia/cachexia syndromes in diverse diseases such as cancer, chronic renal and cardiac failure, and chronic obstructive lung disease. These elevated serum levels are similar to those required to induce this syndrome in animals. Recent identifications of its previously elusive receptor as GFRAL, has enhanced understanding of its biology and suggests that modulating the MIC-1/GDF15-GFRAL pathway may be a therapeutic target for anorexia/cachexia syndrome.

SUMMARY

Inhibiting MIC-1/GDF15 or its receptor GFRAL are high-value potential targets for treatment of anorexia/cachexia syndrome in patients whose elevated serum levels may justify its use.

Tumor Transcriptome Reveals High Expression of IL-8 in Non-Small Cell Lung Cancer Patients with Low Pectoralis Muscle Area and Reduced Survival

Cachexia is a syndrome characterized by an ongoing loss of skeletal muscle mass associated with poor patient prognosis in non-small cell lung cancer (NSCLC). However, prognostic cachexia biomarkers in NSCLC are unknown. Here, we analyzed computed tomography (CT) images and tumor transcriptome data to identify potentially secreted cachexia biomarkers (PSCB) in NSCLC patients with low-muscularity. We integrated radiomics features (pectoralis muscle, sternum, and tenth thoracic (T10) vertebra) from CT of 89 NSCLC patients, which allowed us to identify an index for screening muscularity. Next, a tumor transcriptomic-based secretome analysis from these patients (discovery set) was evaluated to identify potential cachexia biomarkers in patients with low-muscularity. The prognostic value of these biomarkers for predicting recurrence and survival outcome was confirmed using expression data from eight lung cancer datasets (validation set). Finally, C2C12 myoblasts differentiated into myotubes were used to evaluate the ability of the selected biomarker, interleukin (IL)-8, in inducing muscle cell atrophy. We identified 75 over-expressed transcripts in patients with low-muscularity, which included IL-6, CSF3, and IL-8. Also, we identified NCAM1, CNTN1, SCG2, CADM1, IL-8, NPTX1, and APOD as PSCB in the tumor secretome. These PSCB were capable of distinguishing worse and better prognosis (recurrence and survival) in NSCLC patients. IL-8 was confirmed as a predictor of worse prognosis in all validation sets. In vitro assays revealed that IL-8 promoted C2C12 myotube atrophy. Tumors from low-muscularity patients presented a set of upregulated genes encoding for secreted proteins, including pro-inflammatory cytokines that predict worse overall survival in NSCLC. Among these upregulated genes, IL-8 expression in NSCLC tissues was associated with worse prognosis, and the recombinant IL-8 was capable of triggering atrophy in C2C12 myotubes.

Modeling Human Cancer-induced Cachexia

Cachexia is a wasting syndrome characterized by pronounced skeletal muscle loss. In cancer, cachexia is associated with increased morbidity and mortality and decreased treatment tolerance. Although advances have been made in understanding the mechanisms of cachexia, translating these advances to the clinic has been challenging. One reason for this shortcoming may be the current animal models, which fail to fully recapitulate the etiology of human cancer-induced tissue wasting. Because pancreatic ductal adenocarcinoma (PDA) presents with a high incidence of cachexia, we engineered a mouse model of PDA that we named KPP. KPP mice, similar to PDA patients, progressively lose skeletal and adipose mass as a consequence of their tumors. In addition, KPP muscles exhibit a similar gene ontology as cachectic patients. We envision that the KPP model will be a useful resource for advancing our mechanistic understanding and ability to treat cancer cachexia.

Cancer-driven changes link T cell frequency to muscle strength in people with cancer: a pilot study

BACKGROUND

Tumour growth can promote the loss of muscle mass and function. This is particularly disturbing because overall survival is significantly reduced in people with weaker and smaller skeletal muscle. The risk of cancer is also greater in people who are immune deficient. Muscle wasting in mice with cancer can be inhibited by infusion of CD4⁺ precursor T cells that restore balanced ratios of naïve, memory, and regulatory T cells. These data are consistent with the hypothesis that stronger anti-cancer T cell immunity leads to improved muscle mass and function. As a first step to testing this hypothesis, we determined whether levels of circulating T cell subsets correlate with levels of muscle strength in people with cancer.

METHODS

The frequency of circulating CD4⁺ and CD8⁺ naïve, memory, and regulatory T cell subsets was quantified in 11 men with gastrointestinal cancer (aged 59.3 ± 10.1 years) and nine men without cancer (aged 60 ± 13 years), using flow cytometry. T cell marker expression was determined using real-time PCR and western blot analyses in whole blood and peripheral blood mononuclear cells. Handgrip strength, one-repetition maximum chest press, and knee extension tests were used to determine muscle strength. Performance was determined using a stair climb test. Body composition was determined using dual-energy X-ray absorptiometry scan. The Karnofsky and ECOG scales were used to assess functional impairment. Correlations between frequencies of cell subsets with strength, performance, and body composition were determined using regression analyses.

RESULTS

Our data show significant correlations between (i) higher frequencies of CD8⁺ naïve (P = 0.02) and effector memory (P = 0.003) T cells and lower frequencies of CD8⁺ central memory T cells (P = 0.002) with stronger handgrip strength, (ii) lower frequency of regulatory cells with greater lean mass index (P = 0.04), (iii) lower frequency of CD8⁺ T cells that express CD95 with greater stair climb power (P = 0.003), (iv) higher frequency of T cells that co-express CD197 and CD45RA and greater one-repetition maximum knee extension strength (P = 0.008), and (iv) higher expression of CD4 in whole blood with greater functional impairment (P = 0.004) in people with cancer.

CONCLUSIONS

We have identified significant correlations between levels of T cell populations and muscle strength, performance, and body composition in people with cancer. These data justify a follow-up study with a larger cohort to test the validity of the findings.

Effects of microbiota-directed foods in gnotobiotic animals and undernourished children

To examine the contributions of impaired gut microbial community development to childhood undernutrition, we combined metabolomic and proteomic analyses of plasma samples with metagenomic analyses of fecal samples to characterize the biological state of Bangladeshi children with severe acute malnutrition (SAM) as they transitioned, after standard treatment, to moderate acute malnutrition (MAM) with persistent microbiota immaturity. Host and microbial effects of microbiota-directed complementary food (MDCF) prototypes targeting weaning-phase bacterial taxa underrepresented in SAM and MAM microbiota were characterized in gnotobiotic mice and gnotobiotic piglets colonized with age- and growth-discriminatory bacteria. A randomized, double-blind controlled feeding study identified a lead MDCF that changes the abundances of targeted bacteria and increases plasma biomarkers and mediators of growth, bone formation, neurodevelopment, and immune function in children with MAM.

Pancreatic Cancer Cachexia: The Role of Nutritional Interventions

Pancreatic cancer is a cancer with one of the highest mortality rates and many pancreatic cancer patients present with cachexia at diagnosis. The definition of cancer cachexia is not consistently applied in the clinic or across studies. In general, it is “defined as a multifactorial syndrome characterised by an ongoing loss of skeletal muscle mass with or without loss of fat mass that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment.” Many regard cancer cachexia as being resistant to dietary interventions. Cachexia is associated with a negative impact on survival and quality of life. In this article, we outline some of the mechanisms of pancreatic cancer cachexia and discuss nutritional interventions to support the management of pancreatic cancer cachexia. Cachexia is driven by a combination of reduced appetite leading to reduced calorie intake, increased metabolism, and systemic inflammation driven by a combination of host cytokines and tumour derived factors. The ketogenic diet showed promising results, but these are yet to be confirmed in human clinical trials over the long-term. L-carnitine supplementation showed improved quality of life and an increase in lean body mass. As a first step towards preventing and managing pancreatic cancer cachexia, nutritional support should be provided through counselling and the provision of oral nutritional supplements to prevent and minimise loss of lean body mass.

Association of growth differentiation factor 15 with other key biomarkers, functional parameters and mortality in community-dwelling older adults

BACKGROUND

Growth differentiation factor 15 (GDF-15) has been associated with many adverse age-related outcomes and other age-related disorders. The aim of the study was to investigate if baseline levels of GDF-15 are associated with total mortality in community living, older adults during eight years of follow-up after simultaneous consideration of key biomarkers and functional parameters.

METHODS

prospective cohort study including 1,470 community-dwelling older adults aged 65 years or older. GDF-15 was measured by ElectroChemi-Lumisnescence Immunoassays (Roche, Mannheim, Germany). We used Cox-proportional hazards regression to estimate the association of GDF-15 levels with 8-year all-cause mortality.

RESULTS

GDF-15 levels were independently of age and sex strongly associated with many biomarkers such as CRP, IL-6, NT-proBNP, hs-troponines as well as with lipids, metabolic and endocrine markers and kidney function (all P-values < 0.001). GDF-15 showed also a statistically significant correlation to gait speed, hand grip strength and walking duration. In addition, we found a consistent association between levels of GDF-15 and risk of subsequent all-cause mortality which persisted after additional adjustment for key markers of inflammation, cardiac function and damage, and physical function. The hazard ratio (HR) per unit increase of log-transformed GDF-15 was 1.72 (95% CI 1.35; 2.18).

CONCLUSIONS

GDF-15 levels were not only strongly associated with many functional parameters and key biomarkers independently of age and sex, but also with 8-year all-cause mortality even after adjusting for gait speed, NT-proBNP and hs-TnT.

mTORC1 underlies age-related muscle fiber damage and loss by inducing oxidative stress and catabolism

Aging leads to skeletal muscle atrophy (i.e., sarcopenia), and muscle fiber loss is a critical component of this process. The mechanisms underlying these age-related changes, however, remain unclear. We show here that mTORC1 signaling is activated in a subset of skeletal muscle fibers in aging mouse and human, colocalized with fiber damage. Activation of mTORC1 in TSC1 knockout mouse muscle fibers increases the content of morphologically abnormal mitochondria and causes progressive oxidative stress, fiber damage, and fiber loss over the lifespan. Transcriptomic profiling reveals that mTORC1's activation increases the expression of growth differentiation factors (GDF3, 5, and 15), and of genes involved in mitochondrial oxidative stress and catabolism. We show that increased GDF15 is sufficient to induce oxidative stress and catabolic changes, and that mTORC1 increases the expression of GDF15 via phosphorylation of STAT3. Inhibition of mTORC1 in aging mouse decreases the expression of GDFs and STAT3's phosphorylation in skeletal muscle, reducing oxidative stress and muscle fiber damage and loss. Thus, chronically increased mTORC1 activity contributes to age-related muscle atrophy, and GDF signaling is a proposed mechanism.

Body composition and nutritional status in malignant pleural mesothelioma: implications for activity levels and quality of life

BACKGROUND/OBJECTIVES

Malignant pleural mesothelioma (MPM) is an incurable cancer and optimizing daily physical activity and quality of life are key goals of patient management. Little is known about the prevalence of pre-sarcopenia and malnutrition in MPM or their associations with patient outcomes. This study aimed to determine the prevalence of pre-sarcopenia and malnutrition in MPM and investigate if activity levels and quality of life differed according to body composition and nutritional status.

SUBJECTS/METHODS

Patients with a diagnosis of MPM were recruited. Pre-sarcopenia was defined as low appendicular skeletal muscle mass (≤ 7.26 kg/m² for men and ≤ 5.45 kg/m² for women), measured by dual energy X-ray absorptiometry. Malnutrition was defined as a rating of B or C on the Patient-Generated Subjective Global Assessment. Outcome measures included objective activity levels (Actigraph GT3X) and health-related quality of life (HRQoL; Functional Assessment of Cancer Therapy General).

RESULTS

Sixty-one people participated (79% male, median age 69 [IQR 62-74] years and median BMI 25.8 [IQR 24.3-28.4] kg/m²). Fifty-four percent were pre-sarcopenic and 38% were malnourished. Percent of time spent in light activity/day was lower in participants with pre-sarcopenia compared with non-sarcopenic participants (median 25.4 [IQR 19.8-32.1]% vs. 32.3 [27.1-35.6]%; p = 0.008). Participants with malnutrition had poorer HRQoL than well-nourished participants (mean 69.0 (16.3) vs. 84.4 (13.3); p < 0.001).

CONCLUSION

Participants with MPM had high rates of pre-sarcopenia and malnutrition. Pre-sarcopenia was associated with poorer activity levels, whilst malnutrition was associated with poorer quality of life. Interventions that aim to address reduced muscle mass and weight loss, should be tested in MPM to assess their impact on patient outcomes.

Analysis of GDF15 and IGFBP7 in Hyperemesis Gravidarum Support Causality

Objective Hyperemesis gravidarum, severe nausea and vomiting in pregnancy, occurs in up to 2% of pregnancies and leads to significant weight loss, dehydration, electrolyte imbalance, and ketonuria. It is associated with both maternal and fetal morbidity. Familial aggregation studies and twin studies suggest a genetic component. In a recent GWAS, we showed that placentation, appetite, and cachexia genes GDF15 and IGFBP7 are linked to hyperemesis gravidarum (HG). The purpose of this study is to determine whether GDF15 and IGFBP7 are upregulated in HG patients.

Methods We compared serum levels of GDF15 and IGFBP7 at 12 and 24 weeksʼ gestation in women hospitalized for HG, and two control groups, women with nausea and vomiting of pregnancy (NVP), and women with no NVP.

Results We show GDF15 and IGFBP7 serum levels are significantly increased in women with HG at 12 weeksʼ gestation. Serum levels of hCG are not significantly different between cases and controls. At 24 weeks gestation, when symptoms have largely resolved, there is no difference in GDF15 and IGFBP7 serum levels between cases and controls.

Conclusion This study supports GDF15 and IGFBP7 in the pathogenesis of HG and may be useful for prediction and diagnosis. The GDF15-GFRAL brainstem-activated pathway was recently identified and therapies to treat conditions of abnormal appetite are under intense investigation. Based on our findings, HG should be included.

GDNF and the RET Receptor in Cancer: New Insights and Therapeutic Potential

The Glial cell line-derived neurotrophic Family Ligands (GFL) are soluble neurotrophic factors that are required for development of multiple human tissues, but which are also important contributors to human cancers. GFL signaling occurs through the transmembrane RET receptor tyrosine kinase, a well-characterized oncogene. GFL-independent RET activation, through rearrangement or point mutations occurs in thyroid and lung cancers. However, GFL-mediated activation of wildtype RET is an increasingly recognized mechanism promoting tumor growth and dissemination of a much broader group of cancers. RET and GFL expression have been implicated in metastasis or invasion in diverse human cancers including breast, pancreatic, and prostate tumors, where they are linked to poorer patient prognosis. In addition to directly inducing tumor growth in these diseases, GFL-RET signaling promotes changes in the tumor microenvironment that alter the surrounding stroma and cellular composition to enhance tumor invasion and metastasis. As such, GFL RET signaling is an important target for novel therapeutic approaches to limit tumor growth and spread and improve disease outcomes.

Inter-tissue communication in cancer cachexia

Cachexia is a systemic condition that occurs during many neoplastic diseases, such as cancer. Cachexia in cancer is characterized by loss of body weight and muscle and by adipose tissue wasting and systemic inflammation. Cancer cachexia is often associated with anorexia and increased energy expenditure. Even though the cachectic condition severely affects skeletal muscle, a tissue that accounts for ~40% of total body weight, it represents a multi-organ syndrome that involves tissues and organs such as white adipose tissue, brown adipose tissue, bone, brain, liver, gut and heart. Indeed, evidence suggests that non-muscle tissues and organs, as well as tumour tissues, secrete soluble factors that act on skeletal muscle to promote wasting. In addition, muscle tissue also releases various factors that can interact with the metabolism of other tissues during cancer. In this Review, we examine the effect of non-muscle tissues and inter-tissue communication in cancer cachexia and discuss studies aimed at developing novel therapeutic strategies for the condition.

The MIC-1/GDF15-GFRAL Pathway in Energy Homeostasis: Implications for Obesity, Cachexia, and Other Associated Diseases

MIC-1/GDF15 is a stress response cytokine and a distant member of the transforming growth factor beta (TGFb) superfamily, with no close relatives. It acts via a recently identified receptor called glial-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL), which is a distant orphan member of the GDNF receptor family that signals through the tyrosine kinase receptor Ret. MIC-1/GDF15 expression and serum levels rise in response to many stimuli that initiate cell stress and as part of a wide variety of disease processes, most prominently cancer and cardiovascular disease. The best documented actions of MIC-1/GDF15 are on regulation of energy homeostasis. When MIC-1/GDF15 serum levels are substantially elevated in diseases like cancer, it subverts a physiological pathway of appetite regulation to induce an anorexia/cachexia syndrome initiated by its actions on hindbrain neurons. These effects make it a potential target for the treatment of both obesity and anorexia/cachexia syndromes, disorders lacking any highly effective, readily accessible therapies.

Uniting GDF15 and GFRAL: Therapeutic Opportunities in Obesity and Beyond

Growth differentiation factor-15 (GDF15) is a circulating protein that has been implicated in multiple biological processes, including energy homeostasis, body weight regulation, and cachexia driven by cancer and chronic disease. The potential to target GDF15 in the treatment of energy-intake disorders, including obesity and anorexia, is an area of intense investigation, but has been limited by the lack of an identified receptor, signaling mechanism, and target tissue. GDNF family receptor α-like (GFRAL) was recently identified as the neuronal brainstem receptor responsible for mediating the anorectic actions of GDF15. Herein, we provide a brief overview of GDF15 biology with a focus on energy homeostasis, and highlight the implications of the recent receptor identification to this field and beyond.

Physiological culture conditions alter myotube morphology and responses to atrophy treatments: implications for in vitro research on muscle wasting

Standard in vitro myotube culture conditions are nonphysiological and there is increasing evidence that this may distort adaptations to both catabolic and anabolic stimuli and hamper preclinical research into mechanisms and treatments for muscle atrophy in cancer and other chronic diseases. We tested a new model of myotube culture which mimics more accurately the basal conditions for muscle tissue in patients with chronic disease, such as cancer. Myotubes derived from C2C12 myoblasts, cultured under the modified conditions were thinner, more numerous, with more uniform morphology and an increased proportion of mature myotubes. Furthermore, modified conditions led to increased expression of mir-210-3p, genes related to slow-twitch, oxidative phenotype and resistance to commonly used experimental atrophy-inducing treatments. However, treatment with a combination of drugs used in anti-cancer treatment (doxorubicin and dexamethasone) under the modified culture conditions did lead to myotube atrophy which was only partially prevented by co-administration of curcumin. The results underline the importance and potential advantages of using physiological conditions for in vivo experiments investigating mechanisms of muscle atrophy and especially for preclinical screening of therapies for cancer-related muscle wasting.

Plasma inflammatory cytokines and survival of pancreatic cancer patients

OBJECTIVES

Inflammation and inflammatory conditions have been associated with pancreatic cancer risk and progression in a number of clinical, epidemiological, and animal model studies. The goal of the present study is to identify plasma markers of inflammation associated with survival of pancreatic cancer patients, and assess their joint contribution to patient outcome.

METHODS

We measured circulating levels of four established markers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), soluble tumor necrosis factor receptor type II (sTNF-RII), and macrophage inhibitory cytokine-1 (MIC-1)) in 446 patients enrolled in an ongoing prospective clinic-based study. Hazard ratios (HRs) and 95% confidence intervals (CI) for death were estimated using multivariate Cox proportional hazards models.

RESULTS

Overall mortality was significantly increased in patients in the top quartile of CRP (HR = 2.52, 95% CI: 1.82-3.49), IL-6 (HR = 2.78, 95% CI: 2.03-3.81), sTNF-RII (HR = 2.00, 95% CI: 1.46-2.72), and MIC-1 (HR = 2.53, 95% CI: 1.83-3.50), compared to those in the bottom quartile (P-trend <0.0001 for all four comparisons). Furthermore, patients with higher circulating concentrations of all four cytokines had a median survival of 3.7 months; whereas, those with lower levels had a median survival of 19.2 months (HR = 4.55, 95% CI: 2.87-7.20, P-trend <0.0001).

CONCLUSION

Individual elevated plasma inflammatory cytokines are associated with significant and dramatic reductions in pancreatic cancer patient survival. Furthermore, we observed an independent combined effect of those cytokines on patient survival, suggesting that multiple inflammatory pathways are likely involved in PDAC progression. Future research efforts to target the inflammatory state using combination strategies in pancreatic cancer patients are warranted.

Circulating monocyte chemoattractant protein-1 (MCP-1) is associated with cachexia in treatment-naïve pancreatic cancer patients

BACKGROUND

Cancer-associated wasting, termed cancer cachexia, has a profound effect on the morbidity and mortality of cancer patients but remains difficult to recognize and diagnose. While increases in circulating levels of a number of inflammatory cytokines have been associated with cancer cachexia, these associations were generally made in patients with advanced disease and thus may be associated with disease progression rather than directly with the cachexia syndrome. Thus, we sought to assess potential biomarkers of cancer-induced cachexia in patients with earlier stages of disease.

METHODS

A custom multiplex array was used to measure circulating levels of 25 soluble factors from 70 pancreatic cancer patients undergoing attempted tumour resections. A high-sensitivity multiplex was used for increased sensitivity for nine cytokines.

RESULTS

Resectable pancreatic cancer patients with cachexia had low levels of canonical pro-inflammatory cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), interferon-γ (IFN-γ), and tumour necrosis factor (TNF). Even in our more sensitive analysis, these cytokines were not associated with cancer cachexia. Of the 25 circulating factors tested, only monocyte chemoattractant protein-1 (MCP-1) was increased in treatment-naïve cachectic patients compared with weight stable patients and identified as a potential biomarker for cancer cachexia. Although circulating levels of leptin and granulocyte-macrophage colony-stimulating factor (GM-CSF) were found to be decreased in the same cohort of treatment-naïve cachectic patients, these factors were closely associated with body mass index, limiting their utility as cancer cachexia biomarkers.

CONCLUSIONS

Unlike in advanced disease, it is possible that cachexia in patients with resectable pancreatic cancer is not associated with high levels of classical markers of systemic inflammation. However, cachectic, treatment-naïve patients have higher levels of MCP-1, suggesting that MCP-1 may be useful as a biomarker of cancer cachexia.

Placenta and appetite genes GDF15 and IGFBP7 are associated with hyperemesis gravidarum

Hyperemesis gravidarum (HG), severe nausea and vomiting of pregnancy, occurs in 0.3-2% of pregnancies and is associated with maternal and fetal morbidity. The cause of HG remains unknown, but familial aggregation and results of twin studies suggest that understanding the genetic contribution is essential for comprehending the disease etiology. Here, we conduct a genome-wide association study (GWAS) for binary (HG) and ordinal (severity of nausea and vomiting) phenotypes of pregnancy complications. Two loci, chr19p13.11 and chr4q12, are genome-wide significant (p < 5 × 10-8) in both association scans and are replicated in an independent cohort. The genes implicated at these two loci are GDF15 and IGFBP7 respectively, both known to be involved in placentation, appetite, and cachexia. While proving the casual roles of GDF15 and IGFBP7 in nausea and vomiting of pregnancy requires further study, this GWAS provides insights into the genetic risk factors contributing to the disease.

Cancer-associated cachexia

Cancer-associated cachexia is a disorder characterized by loss of body weight with specific losses of skeletal muscle and adipose tissue. Cachexia is driven by a variable combination of reduced food intake and metabolic changes, including elevated energy expenditure, excess catabolism and inflammation. Cachexia is highly associated with cancers of the pancreas, oesophagus, stomach, lung, liver and bowel; this group of malignancies is responsible for half of all cancer deaths worldwide. Cachexia involves diverse mediators derived from the cancer cells and cells within the tumour microenvironment, including inflammatory and immune cells. In addition, endocrine, metabolic and central nervous system perturbations combine with these mediators to elicit catabolic changes in skeletal and cardiac muscle and adipose tissue. At the tissue level, mechanisms include activation of inflammation, proteolysis, autophagy and lipolysis. Cachexia associates with a multitude of morbidities encompassing functional, metabolic and immune disorders as well as aggravated toxicity and complications of cancer therapy. Patients experience impaired quality of life, reduced physical, emotional and social well-being and increased use of healthcare resources. To date, no effective medical intervention completely reverses cachexia and there are no approved drug therapies. Adequate nutritional support remains a mainstay of cachexia therapy, whereas drugs that target overactivation of catabolic processes, cell injury and inflammation are currently under investigation.

New extracellular factors in glioblastoma multiforme development: neurotensin, growth differentiation factor-15, sphingosine-1-phosphate and cytomegalovirus infection

Recent years have seen considerable progress in understanding the biochemistry of cancer. For example, more significance is now assigned to the tumor microenvironment, especially with regard to intercellular signaling in the tumor niche which depends on many factors secreted by tumor cells. In addition, great progress has been made in understanding the influence of factors such as neurotensin, growth differentiation factor-15 (GDF-15), sphingosine-1-phosphate (S1P), and infection with cytomegalovirus (CMV) on the 'hallmarks of cancer' in glioblastoma multiforme. Therefore, in the present work we describe the influence of these factors on the proliferation and apoptosis of neoplastic cells, cancer stem cells, angiogenesis, migration and invasion, and cancer immune evasion in a glioblastoma multiforme tumor. In particular, we discuss the effect of neurotensin, GDF-15, S1P (including the drug FTY720), and infection with CMV on tumor-associated macrophages (TAM), microglial cells, neutrophil and regulatory T cells (T_reg), on the tumor microenvironment. In order to better understand the role of the aforementioned factors in tumoral processes, we outline the latest models of intratumoral heterogeneity in glioblastoma multiforme. Based on the most recent reports, we discuss the problems of multi-drug therapy in treating glioblastoma multiforme.

Casting the net broader to confirm our imaginations: the long road to treating wasting disorders

Wasting embraces muscle and tissue wasting in sarcopenia and cachexia. This article describes recent advances in the field published in the Journal of Cachexia, Sarcopenia and Muscle concerning diagnostic tools, biomarker development, pathophysiology, and treatment. Studies discussed herein embrace those on sarcopenia and cachexia in heart failure, chronic obstructive pulmonary disease, and cancer including also animal models.

Protein calorie malnutrition, nutritional intervention and personalized cancer care

Cancer patients often experience weight loss caused by protein calorie malnutrition (PCM) during the course of the disease or treatment. PCM is expressed as severe if the patient has two or more of the following characteristics: obvious significant muscle wasting, loss of subcutaneous fat; nutritional intake of <50% of recommended intake for 2 weeks or more; bedridden or otherwise significantly reduced functional capacity; weight loss of >2% in 1 week, 5% in 1 month, or 7.5% in 3 months. Cancer anorexia-cachexia syndrome (CACS) is a multifactorial condition of advanced PCM associated with underlying illness (in this case cancer) and is characterized by loss of muscle with or without loss of fat mass. Cachexia is defined as weight loss of more than 5% of body weight in 12 months or less in the presence of chronic disease. Hence with a chronic illness on board even a small amount of weight loss can open the door to cachexia. These nutritional challenges can lead to severe morbidity and mortality in cancer patients. In the clinic, the application of personalized medicine and the ability to withstand the toxic effects of anti-cancer therapies can be optimized when the patient is in nutritional homeostasis and is free of anorexia and cachexia. Routine assessment of nutritional status and appropriate intervention are essential components of the effort to alleviate effects of malnutrition on quality of life and survival of patients.

An analysis of the types of recently published research in the field of cachexia

Introduction Cachexia is a common complication of many and varied chronic disease processes, yet it has received very little attention as an area of clinical research effort until recently. We sought to survey the contemporary literature on published research into cachexia to define where it is being published and the proportion of output classified into the main types of research output. Methods I searched the PubMed listings under the topic research term "cachexia" and related terms for articles published in the calendar years of 2015 and 2016, regardless of language. Searches were conducted and relevant papers extracted by two observers, and disagreements were resolved by consensus. Results There were 954 publications, 370 of which were review articles or commentaries, 254 clinical observations or non-randomised trials, 246 original basic science reports and only 26 were randomised controlled trials. These articles were published in 478 separate journals but with 36% of them being published in a core set of 23 journals. The H-index of these papers was 25 and there were 147 papers with 10 or more citations. Of the top 100 cited papers, 25% were published in five journals. Of the top cited papers, 48% were review articles, 18% were original basic science, and 7% were randomised clinical trials. Discussion This analysis shows a steady but modest increase in publications concerning cachexia with a strong pipeline of basic science research but still a relative lack of randomised clinical trials, with none exceeding 1000 patients. Research in cachexia is still in its infancy, but the solid basic science effort offers hope that translation into randomised controlled clinical trials may eventually lead to effective therapies for this troubling and complex clinical disease process.

Biomarkers of cancer cachexia

Cachexia is a complex multifactorial syndrome, characterized by loss of skeletal muscle and fat mass, which affects the majority of advanced cancer patients and is associated with poor prognosis. Interestingly, reversing muscle loss in animal models of cancer cachexia leads to prolong survival. Therefore, detecting cachexia and maintaining muscle mass represent a major goal in the care of cancer patients. However, early diagnosis of cancer cachexia is currently limited for several reasons. Indeed, cachexia development is variable according to tumor and host characteristics. In addition, safe, accessible and non-invasive tools to detect skeletal muscle atrophy are desperately lacking in clinical practice. Finally, the precise molecular mechanisms and the key players involved in cancer cachexia remain poorly characterized. The need for an early diagnosis of cancer cachexia supports therefore the quest for a biomarker that might reflect skeletal muscle atrophy process. Current research offers different promising ways to identify such a biomarker. Initially, the quest for a biomarker of cancer cachexia has mostly focused on mediators of muscle atrophy, produced by both tumor and host, in an attempt to define new therapeutic approaches. In another hand, molecules released by the muscle into the circulation during the atrophy process have been also considered as potential biomarkers. More recently, several "omics" studies are emerging to identify new muscular or circulating markers of cancer cachexia. Some genetic markers could also contribute to identify patients more susceptible to develop cachexia. This article reviews our current knowledge regarding potential biomarkers of cancer cachexia.

The Effects of Neoadjuvant Axitinib on Anthropometric Parameters in Patients With Locally Advanced Non-metastatic Renal Cell Carcinoma

OBJECTIVE

To examine the effect that neoadjuvant axitinib for the treatment of localized renal cell carcinoma has on body compartment composition.

MATERIALS AND METHODS

The study was based on a single-institution, single-arm clinical trial that enrolled 24 patients with locally advanced non-metastatic biopsy-proven clear cell renal cell carcinoma. Patients received axitinib orally for up to 12 weeks. Computed tomography scans were completed before the start of treatment, after 7 weeks of treatment and at the completion of 12 weeks of treatment. Patients underwent nephrectomy after axitinib treatment. The primary outcome of the current study was change in body compartment composition. Secondary outcomes included development of new-onset sarcopenia and changes in body weight.

RESULTS

A total of 23 patients had a complete set of imaging for evaluation, of which 19 (82.6%) lost weight. Median weight loss was 4.5 kg (P <.001). Seven patients (30.4%) had sarcopenia before treatment, with an additional 5 (21.7%) developing sarcopenia during treatment. Median decrease in skeletal muscle was 2.9 cm²/m² (P <.001), visceral adipose tissue was 4.9 cm²/m² (P = .132), and subcutaneous adipose tissue was 1.0 cm²/m² (P = .043). Ten of the 16 patients (62.5%) without baseline sarcopenia achieved a partial response, whereas only 1 of the 7 patients (14.3%) with baseline pretreatment sarcopenia achieved a partial response (P = .069).

CONCLUSION

Neoadjuvant axitinib resulted in a decrease in skeletal muscle and subcutaneous adipose tissue, as well as weight loss. Patients with baseline sarcopenia tended to have a lower response rate to neoadjuvant axitinib.

The impact of exercise training on adipose tissue remodelling in cancer cachexia

Cachexia affects the majority of patients with advanced cancer and no effective treatment is currently available to address this paraneoplastic syndrome. It is characterized by a reduction in body weight due to the loss of white adipose tissue (WAT) and skeletal muscle. The loss of WAT seems to occur at an earlier time point than skeletal muscle proteolysis, with recent evidence suggesting that the browning of WAT may be a major contributor to this process. Several factors seem to modulate WAT browning including pro-inflammatory cytokines; however, the underlying molecular pathways are poorly characterized. Exercise training is currently recommended for the clinical management of low-grade inflammatory conditions as cancer cachexia. While it seems to counterbalance the impairment of skeletal muscle function and attenuate the loss of muscle mass, little is known regarding its effects in adipose tissue. The browning of WAT is one of the mechanisms through which exercise improves body composition in overweight/obese individuals. While this effect is obviously advantageous in this clinical setting, it remains to be clarified if exercise training could protect or exacerbate the cachexia-related catabolic phenotype occurring in adipose tissue of cancer patients. Herein, we overview the molecular players involved in adipose tissue remodelling in cancer cachexia and in exercise training and hypothesize on the mechanisms modulated by the synergetic effect of these conditions. A better understanding of how physical activity regulates body composition will certainly help in the development of successful multimodal therapeutic strategies for the clinical management of cancer cachexia.

Anorexia-cachexia syndrome in hepatoma tumour-bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC-1/GDF15

BACKGROUND

The cancer-anorexia-cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour-derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour-derived macrophage inhibitory cytokine-1 (MIC-1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC-1 in mice.

METHODS

Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC-1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response.

RESULTS

In tumour-bearing sham-operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer-induced anorexia or body weight loss. Tumour-bearing rats had substantially increased MIC-1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake.

CONCLUSIONS

These findings demonstrate the importance of the AP in the mediation of cancer-dependent anorexia and body weight loss and support a pathological role of MIC-1 as a tumour-derived factor mediating CACS, possibly via an AP-dependent action.

Long-lasting effect of obesity on skeletal muscle transcriptome

BACKGROUND

Reduced physical activity and increased intake of calorically-dense diets are the main risk factors for obesity, glucose intolerance, and type 2 diabetes. Chronic overnutrition and hyperglycemia can alter gene expression, contributing to long-term obesity complications. While caloric restriction can reduce obesity and glucose intolerance, it is currently unknown whether it can effectively reprogram transcriptome to a pre-obesity level. The present study addressed this question by the preliminary examination of the transcriptional dynamics in skeletal muscle after exposure to overnutrition and following caloric restriction.

RESULTS

Six male rhesus macaques of 12-13 years of age consumed a high-fat western-style diet for 6 months and then were calorically restricted for 4 months without exercise. Skeletal muscle biopsies were subjected to longitudinal gene expression analysis using next-generation whole-genome RNA sequencing. In spite of significant weight loss and normalized insulin sensitivity, the majority of WSD-induced (n = 457) and WSD-suppressed (n = 47) genes remained significantly dysregulated after caloric restriction (FDR ≤0.05). The Metacore^TM pathway analysis reveals that western-style diet induced the sustained activation of the transforming growth factor-β gene network, associated with extracellular matrix remodeling, and the downregulation of genes involved in muscle structure development and nutritional processes.

CONCLUSIONS

Western-style diet, in the absence of exercise, induced skeletal muscle transcriptional programing, which persisted even after insulin resistance and glucose intolerance were completely reversed with caloric restriction.

Growth differentiation factor-15 is a predictor of important disease outcomes in patients with COPD

Increased levels of growth differentiation factor-15 (GDF15) are associated with cachexia, cardiovascular disease and all-cause mortality. The role of GDF15 in chronic obstructive pulmonary disease (COPD) is unknown.

The study included 413 patients with COPD from the Bergen COPD Cohort Study. All patients had a forced expiratory volume in 1 s (FEV1) <80% predicted, a FEV1 to forced vital capacity (FVC) ratio <0.7 and a history of smoking. Spirometry, fat free mass index, blood gases and plasma GDF15 were measured at baseline. Patients were followed for 3 years regarding exacerbations and changes in lung function, and 9 years for mortality. Yearly exacerbation rate, survival and yearly change in FEV1/FVC were evaluated with regression models.

Median plasma GDF15 was 0.86 ng·mL−1 (interquartile range 0.64–1.12 ng·mL−1). The distribution was not normal and GDF15 was analysed as a categorical variable. High levels of GDF15 were associated with a higher exacerbation rate (incidence rate ratio 1.39, 95% CI 1.1–1.74, p=0.006, adjusted values). Furthermore, high levels of GDF15 were associated with higher mortality (hazard ratio 2.07, 95% CI 1.4–3.1, p<0.001) and an increased decline in both FEV1 (4.29% versus 3.25%) and FVC (2.63% versus 1.44%) in comparison to low levels (p<0.01 for both).

In patients with COPD, high levels of GDF15 were independently associated with a higher yearly rate of exacerbations, higher mortality and increased decline in both FEV1 and FVC.

Association of Growth Differentiation Factor 15 with Mortality in a Prospective Hemodialysis Cohort

BACKGROUND/AIMS

Cardiovascular disease and protein-energy wasting are among the strongest predictors of the high mortality of dialysis patients. In the general population, the novel cardiovascular and wasting biomarker, growth differentiation factor 15 (GDF15), is associated with decreased survival. However, little is known about GDF15 in dialysis patients.

METHODS

Among prevalent hemodialysis patients participating in a prospective study (October 2011 to August 2015), we examined the association of baseline GDF15 levels with all-cause mortality using unadjusted and case mix-adjusted death hazard ratios (HRs) that controlled for age, sex, race, ethnicity, diabetes, and dialysis vintage.

RESULTS

The mean age ± SD of the 203 patients included in the study was 53.2 ± 14.5 years, and the cohort included 41% females, 34% African-Americans, and 48% Hispanics. GDF15 levels (mean ± SD 5.94 ± 3.90 ng/mL; range 1.58-39.8 ng/mL) were higher among older patients and were inversely associated with serum creatinine concentrations as a surrogate for muscle mass. Each 1.0 ng/mL increase in GDF15 was associated with an approximately 17-18% higher mortality risk in the unadjusted and case mix models (p < 0.05). Increments of about 1 SD (a 4.0 ng/mL increase in GDF15) were associated with a nearly 2-fold higher death risk. The highest GDF15 tertile was associated with higher mortality risk (reference: lowest tertile): the HRs (95% CI) were 3.19 (1.35-7.55) and 2.45 (1.00-6.00) in the unadjusted and the case mix-adjusted model, respectively. These incremental death trends were confirmed in cubic spline models.

CONCLUSION

Higher circulating GDF15 levels are associated with higher mortality risk in hemodialysis patients. Future studies are needed to determine whether GDF15 may represent a novel therapeutic target for cardiovascular disease, wasting, and death in this population.

STAT3 in the systemic inflammation of cancer cachexia

Weight loss is diagnostic of cachexia, a debilitating syndrome contributing mightily to morbidity and mortality in cancer. Most research has probed mechanisms leading to muscle atrophy and adipose wasting in cachexia; however cachexia is a truly systemic phenomenon. Presence of the tumor elicits an inflammatory response and profound metabolic derangements involving not only muscle and fat, but also the hypothalamus, liver, heart, blood, spleen and likely other organs. This global response is orchestrated in part through circulating cytokines that rise in conditions of cachexia. Exogenous Interleukin-6 (IL6) and related cytokines can induce most cachexia symptomatology, including muscle and fat wasting, the acute phase response and anemia, while IL-6 inhibition reduces muscle loss in cancer. Although mechanistic studies are ongoing, certain of these cachexia phenotypes have been causally linked to the cytokine-activated transcription factor, STAT3, including skeletal muscle wasting, cardiac dysfunction and hypothalamic inflammation. Correlative studies implicate STAT3 in fat wasting and the acute phase response in cancer cachexia. Parallel data in non-cancer models and disease states suggest both pathological and protective functions for STAT3 in other organs during cachexia. STAT3 also contributes to cancer cachexia through enhancing tumorigenesis, metastasis and immune suppression, particularly in tumors associated with high prevalence of cachexia. This review examines the evidence linking STAT3 to multi-organ manifestations of cachexia and the potential and perils for targeting STAT3 to reduce cachexia and prolong survival in cancer patients.