IL-6, cancer and cachexia: metabolic dysfunction creates the perfect storm

A history of polymyalgia rheumatica: a narrative review

Polymyalgia rheumatica (PMR) is characterized by stiffness and pain in the shoulders, hips and neck and presents most commonly in the eighth decade. It can coexist with giant cell arteritis and the two diseases may share some pathophysiological mechanisms. This narrative review considers present-day ideas about PMR in a historical context, from the first names and descriptions of this disease entity, via successive generations of classification criteria sets, and finally to implications for clinical diagnosis. The characteristic distribution of musculoskeletal inflammation in PMR and its relationship to vasculitic and synovitic diseases have framed the way that PMR is described, classified, diagnosed and treated. A response to glucocorticoids is not specific to PMR and so it is important for rheumatologists to support general practitioners in making a definite diagnosis. Multi-stakeholder collaboration will improve current pathways for fast, accurate diagnosis and safe and effective treatment.

Mutant RAS-driven Secretome Causes Skeletal Muscle Defects in Breast Cancer

Cancer-induced skeletal muscle defects differ in severity between individuals with the same cancer type. Cancer subtype-specific genomic aberrations are suggested to mediate these differences, but experimental validation studies are very limited. We utilized three different breast cancer patient-derived xenograft (PDX) models to correlate cancer subtype with skeletal muscle defects. PDXs were derived from brain metastasis of triple-negative breast cancer (TNBC), estrogen receptor-positive/progesterone receptor-positive (ER+/PR+) primary breast cancer from a BRCA2-mutation carrier, and pleural effusion from an ER+/PR- breast cancer. While impaired skeletal muscle function as measured through rotarod performance and reduced levels of circulating and/or skeletal muscle miR-486 were common across all three PDXs, only TNBC-derived PDX activated phospho-p38 in skeletal muscle. To further extend these results, we generated transformed variants of human primary breast epithelial cells from healthy donors using HRASG12V or PIK3CAH1047R mutant oncogenes. Mutations in RAS oncogene or its modulators are found in approximately 37% of metastatic breast cancers, which is often associated with skeletal muscle defects. Although cells transformed with both oncogenes generated adenocarcinomas in NSG mice, only HRASG12V-derived tumors caused skeletal muscle defects affecting rotarod performance, skeletal muscle contraction force, and miR-486, Pax7, pAKT, and p53 levels in skeletal muscle. Circulating levels of the chemokine CXCL1 were elevated only in animals with tumors containing HRASG12V mutation. Because RAS pathway aberrations are found in 19% of cancers, evaluating skeletal muscle defects in the context of genomic aberrations in cancers, particularly RAS pathway mutations, may accelerate development of therapeutic modalities to overcome cancer-induced systemic effects.

SIGNIFICANCE

Mutant RAS- and PIK3CA-driven breast cancers distinctly affect the function of skeletal muscle. Therefore, research and therapeutic targeting of cancer-induced systemic effects need to take aberrant cancer genome into consideration.

Effects of Fermented Polygonum cuspidatum on the Skeletal Muscle Functions

Plant extract fermentation is widely employed to enhance the nutritional and pharmaceutical value of functional foods. Polygonum cuspidatum (Pc) contains flavonoids, anthraquinones, and stilbenes, imparting protective effects against inflammatory diseases, cancer, diabetes, and cardiovascular diseases. However, the effects of fermented Pc on skeletal muscle strength remain unexplored. In this study, we generated fermented Pc using a complex of microorganisms containing Lactobacillus spp. (McPc) and assessed its effects on muscle strength and motor function in mice. Compared to unfermented Pc water extract, elevated levels of emodin and resveratrol were noted in McPc. This was identified and quantified using UPLC-QTOF/MS and HPLC techniques. Gene expression profiling through RNA-seq and quantitative RT-PCR revealed that McPc administration upregulated the expression of genes associated with antioxidants, glycolysis, oxidative phosphorylation, fatty acid oxidation, and mitochondrial biogenesis in cultured C2C12 myotubes and the gastrocnemius muscle in mice. McPc significantly improved skeletal muscle strength, motor coordination, and traction force in mice subjected to sciatic neurectomy and high-fat diet (HFD). McPc administration exhibited more pronounced improvement of obesity, hyperglycemia, fatty liver, and hyperlipidemia in HFD mice compared to control group. These findings support the notion that emodin and resveratrol-enriched McPc may offer health benefits for addressing skeletal muscle weakness.

Association of Body Composition and Handgrip Strength with Interleukin-6 (IL-6) and Vitamin D Level in Cancer Patients

Introduction

Cachexia is prevalent in cancer and is associated with poorer prognosis. We aimed to investigate the association of interleukin-6 (IL-6) and vitamin D levels with cachexia in cancer patients. We also assessed the relationship between body composition profile and cachexia, IL-6, and vitamin D levels.

Methods

A cross-sectional study was conducted at Dharmais National Cancer Hospital. The study included patients with newly diagnosed biopsy-proven nasopharyngeal cancer, lung cancer, breast cancer, cervical cancer, or non-Hodgkin lymphoma. Blood samples, anthropometrics, and body composition were measured.

Results

A total of 150 cancer patients were included in the study, with a median age of 52 years, and 64% (n = 96) are female. The prevalence of cachexia was 57%. Cancer patients with cachexia had higher IL-6 levels (P = 0.025). No association between cachexia and vitamin D levels was found (P = 0.787). Patients with cachexia had lower body composition components than those without cachexia (P < 0.05). Vitamin D levels were positively correlated with muscle mass, visceral fat, and handgrip strength (P < 0.05), while no association between IL-6 and body composition was found.

Conclusion

Cancer-associated cachexia is associated with a higher level of IL-6, lower BMI, lower fat mass index, and lower visceral fat. Vitamin D levels, but not IL-6, are correlated with muscle mass, muscle strength, and visceral fat in cancer patients.

Interleukin-6: A New Marker of Advanced-Sarcopenic HCC Cirrhotic Patients

Hepatocellular carcinoma (HCC) is the major cause of liver-related death worldwide. Interleukin 6 (IL-6) promotes the growth of the HCC microenvironment. The correlation between Child-Pugh (CP) and HCC stage and between HCC stage and sarcopenia is still not clear. Our aim was to investigate whether IL-6 is correlated with HCC stage and could represent a diagnostic marker for sarcopenia. Ninety-three HCC cirrhotic patients in different stages, according to BCLC-2022 (stages A, B, and C), were enrolled. Anthropometric and biochemical parameters, comprehensive of IL-6, were collected. The skeletal muscle index (SMI) was measured using dedicated software on computer tomography (CT) images. IL-6 level was higher in advanced (BCLC C) compared to the early-intermediate (BCLC A-B) stages (21.4 vs. 7.7 pg/mL, p < 0.005). On multivariate analysis, IL-6 levels were statistically dependent on the degree of liver disease severity (CP score) and HCC stages (p = 0.001 and p = 0.044, respectively). Sarcopenic patients presented lower BMI (24.7 ± 5.3 vs. 28.5 ± 7.0), higher PMN/lymphocyte ratio (2.9 ± 2.4 vs. 2.3 ± 1.2) and increased values of log (IL-6) (1.3 ± 0.6 vs. 1.1 ± 0.3). Univariate logistic regression between sarcopenia and log (IL-6) showed a significant odds ratio (OR 14.88, p = 0.044) with an AUC of 0.72. IL-6 appears to be an effective biomarker for the diagnosis of advanced cirrhotic HCC. In addition, IL-6 could be considered a marker of cirrhotic HCC-related sarcopenia, suggesting further investigation with BIA- or CT-dedicated software.

Metabolic switch in cancer - Survival of the fittest

Cell metabolism is characterised by the highly coordinated conversion of nutrients into energy and biomass. In solid cancers, hypoxia, nutrient deficiencies, and tumour vasculature are incompatible with accelerated anabolic growth and require a rewiring of cancer cell metabolism. Driver gene mutations direct malignant cells away from oxidation to maximise energy production and biosynthesis while tumour-secreted factors degrade peripheral tissues to fuel disease progression and initiate metastasis. As it is vital to understand cancer cell metabolism and survival mechanisms, this review discusses the metabolic switch and current drug targets and clinical trials. In the future, metabolic markers may be included when phenotyping individual tumours to improve the therapeutic opportunities for personalised therapy.

A narrative review of the principal glucocorticoids employed in cancer

Glucocorticoids (GCs) are a pharmacological class of drugs widely used in oncology in both supportive and palliative settings. GCs differentially impact organs with immediate and long-term effects; with suppressive effect on the immune system anchoring their use to manage the toxicities of immune checkpoint inhibitors (ICIs). In addition, GCs are often used in the management of symptoms related to cancer or chemotherapy and as adjuvants in the treatment of pain in the management of other. In the palliative setting, GCs, especially administered subcutaneously can be to assist in the control of nausea, dyspnea, asthenia, and anorexia-cachexia syndrome. In this narrative review, we aim to summarize the role of GCs in the different settings (curative, supportive, and palliative) to help clinicians use these important drugs in their daily clinical practice with cancer patients.

Autoimmunity, cancer and COVID-19 abnormally activate wound healing pathways: critical role of inflammation

Recent evidence indicates that targeting IL-6 provides broad therapeutic approaches to several diseases. In patients with cancer, autoimmune diseases, severe respiratory infections [e.g. coronavirus disease 2019 (COVID-19)] and wound healing, IL-6 plays a critical role in modulating the systemic and local microenvironment. Elevated serum levels of IL-6 interfere with the systemic immune response and are associated with disease progression and prognosis. As already noted, monoclonal antibodies blocking either IL-6 or binding of IL-6 to receptors have been used/tested successfully in the treatment of rheumatoid arthritis, many cancer types, and COVID-19. Therefore, in the present review, we compare the impact of IL-6 and anti-IL-6 therapy to demonstrate common (pathological) features of the studied diseases such as formation of granulation tissue with the presence of myofibroblasts and deposition of new extracellular matrix. We also discuss abnormal activation of other wound-healing-related pathways that have been implicated in autoimmune disorders, cancer or COVID-19.

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.

Cancer-Associated Fibroblasts Influence the Biological Properties of Malignant Tumours via Paracrine Secretion and Exosome Production

Cancer-associated fibroblasts (CAFs) are an essential component of the tumour microenvironment. They represent a heterogeneous group of cells that are under the control of cancer cells and can reversely influence the cancer cell population. They affect the cancer cell differentiation status, and the migration and formation of metastases. This is achieved through the production of the extracellular matrix and numerous bioactive factors. IL-6 seems to play the central role in the communication of noncancerous and cancer cells in the tumour. This review outlines the role of exosomes in cancer cells and cancer-associated fibroblasts. Available data on the exosomal cargo, which can significantly intensify interactions in the tumour, are summarised. The role of exosomes as mediators of the dialogue between cancer cells and cancer-associated fibroblasts is discussed together with their therapeutic relevance. The functional unity of the paracrine- and exosome-mediated communication of cancer cells with the tumour microenvironment represented by CAFs is worthy of attention.

Shared and distinct mechanisms of skeletal muscle atrophy: A narrative review

Maintenance of skeletal muscle mass and function is an incredibly nuanced balance of anabolism and catabolism that can become distorted within different pathological conditions. In this paper we intend to discuss the distinct intracellular signaling events that regulate muscle protein atrophy for a given clinical occurrence. Aside from the common outcome of muscle deterioration, several conditions have at least one or more distinct mechanisms that creates unique intracellular environments that facilitate muscle loss. The subtle individuality to each of these given pathologies can provide both researchers and clinicians with specific targets of interest to further identify and increase the efficacy of medical treatments and interventions.

Sustained Systemic Levels of IL-6 Impinge Early Muscle Growth and Induce Muscle Atrophy and Wasting in Adulthood

IL-6 is a pleiotropic cytokine that can exert different and opposite effects. The muscle-induced and transient expression of IL-6 can act in an autocrine or paracrine manner, stimulating anabolic pathways associated with muscle growth, myogenesis, and with regulation of energy metabolism. In contrast, under pathologic conditions, including muscular dystrophy, cancer associated cachexia, aging, chronic inflammatory diseases, and other pathologies, the plasma levels of IL-6 significantly increase, promoting muscle wasting. Nevertheless, the specific physio-pathological role exerted by IL-6 in the maintenance of differentiated phenotype remains to be addressed. The purpose of this study was to define the role of increased plasma levels of IL-6 on muscle homeostasis and the mechanisms contributing to muscle loss. Here, we reported that increased plasma levels of IL-6 promote alteration in muscle growth at early stage of postnatal life and induce muscle wasting by triggering a shift of the slow-twitch fibers toward a more sensitive fast fiber phenotype. These findings unveil a role for IL-6 as a potential biomarker of stunted growth and skeletal muscle wasting.

The systemic pro-inflammatory response: targeting the dangerous liaison between COVID-19 and cancer

Inflammation is an established driver of severe SARS-CoV-2 infection and a mechanism linked to the increased susceptibility to fatal COVID-19 demonstrated by patients with cancer. As patients with cancer exhibit a higher level of inflammation compared with the general patient population, patients with cancer and COVID-19 may uniquely benefit from strategies targeted at overcoming the unrestrained pro-inflammatory response. Targeted and non-targeted anti-inflammatory therapies may prevent end-organ damage in SARS-CoV-2-infected patients with cancer and decrease mortality. Here, we review the clinical role of selective inhibition of pro-inflammatory interleukins, tyrosine kinase modulation, anti-tumor necrosis factor agents, and other non-targeted approaches including corticosteroids in their roles as disease-modulating agents in patients with COVID-19 and cancer. Investigation of these therapeutics in this highly vulnerable patient group is posited to facilitate the development of tailored therapeutics for this patient population, aiding the transition of systemic inflammation from a prognostic domain to a source of therapeutic targets.

Pediatric Inflammatory Multisystem Syndrome (PIMS) - Potential role for cytokines such Is IL-6

COVID-19 is a transmissible respiratory disease caused by coronavirus SARS-CoV-2, which is similar to SARS or MERS. Its increased severity was noted in aged patients usually over 65 years of age. Children and young people have an asymptomatic or mild course of the disease.Unfortunately, the number of children with problems after mild or asymptomatic COVID-19 recovery is increasing and their troubles resemble Kawasaki disease, although the laboratory findings seem to be different. This condition is called pediatric inflammatory multisystem syndrome (PIMS), and it is a new disease seen in children directly influenced by previous SARS-CoV-2 infection. The literature reports that PIMS typically follows 2-4 weeks after SARS-CoV-2 infection. The clinical symptoms of the affected children are extremely complex, ranging from gastrointestinal to cardiovascular problems with frequent skin and mucosal manifestations, and without intensive treatment they can be fatal. The exact causes of PIMS are recently unknown, however, it is explained as hyperactivation of immunity.In this minireview, we summarize data on the prominent role of the IL-6-IL-6R-STAT3 axis in PIMS aetiopathogenesis. Therapeutic manipulation of IL-6 or IL-6 receptor could be an approach to the treatment of children with severe PIMS.

The prevalence of sarcopenia and relationships between dietary intake and muscle mass in head and neck cancer patients undergoing radiotherapy: A longitudinal study

PURPOSE

Our study aims to investigate dietary intake characteristics and their association with skeletal muscle mass in head and neck cancer patients treated with radiotherapy.

METHODS

From March 2017 to August 2018, patients with head and neck cancer who received radiotherapy at our affiliated hospital were enrolled. Dietary intake was assessed through 24-hr dietary recall and skeletal muscle mass was evaluated by bioelectrical impedance analysis at three-time points. Appendicular skeletal muscle mass was adjusted for height squared defined sarcopenia and correlated with dietary intake by generalized estimating equations (GEE).

RESULTS

This study sample comprised 287 patients [median age: 54 years; 187 (65.2%) men]. Median dietary intake at post-treatment was 14.95 kcal/kg/day energy and 0.63 g/kg/day protein. Skeletal muscle mass decreased significantly in all patients. The prevalence of sarcopenia increased from 24.4% before treatment to 46.7% at the end of treatment. Exploratory univariate GEE analysis revealed that radiotherapy time-point, male-gender, age ≥60 and decreased dietary energy intake significantly impacted on muscle loss represented by the appendicular skeletal muscle index. After controlling covariates, dietary energy intake was only positively associated with muscle loss in women (P = 0.013, 95% CI = 0.003-0.027) but not in men (P = 0.788, 95% CI = -0.007-0.009).

CONCLUSION

While the loss in skeletal muscle is more prevalent in men receiving radiotherapy, the effects of dietary energy intake were only associated with women. A prospective randomized clinical trial is required to identify the appropriate amount of dietary energy supplement by gender in cancer patients treated with radiotherapy.

Exercise protects against cardiac and skeletal muscle dysfunction in a mouse model of inflammatory arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory arthritis impacting primarily joints and cardiac and skeletal muscle. RA's distinct impact on cardiac and skeletal muscle tissue is suggested by studies showing that new RA pharmacologic agents strongly improve joint inflammation, but have little impact on RA-associated mortality, cardiovascular disease, and sarcopenia. Thus, the objective is to understand the distinct effects of RA on cardiac and skeletal muscle, and to therapeutically target these tissues through endurance-based exercise as a way to improve RA mortality and morbidity. We utilize the well-characterized RA mouse model, the K/BxN mouse, to investigate cardiac and skeletal muscle pathologies, including the use of wheel-running exercise to mitigate these pathologies. Strikingly, we found that K/BxN mice, like patients with RA, also exhibit both cardiac and skeletal muscle myopathies that were correlated with circulating IL-6 levels. Three months of wheel-running exercise significantly improved K/BxN joint swelling and reduced systemic IL-6 concentrations. Importantly, there were morphological, gene expression, and functional improvements in both the skeletal muscle and cardiac myopathies with exercise. The K/BxN mouse model of RA recapitulated important RA clinical comorbidities, including altered joint, cardiac and skeletal muscle function. These morphological, molecular, and functional alterations were mitigated with regular exercise, thus suggesting exercise as a potential therapeutic intervention to lessen disease activity in the joint and the peripheral tissues, including the heart and skeletal muscle.NEW & NOTEWORTHY RA, even when controlled, is associated with skeletal muscle weakness and greater risk of cardiovascular disease (CVD). Using exercise as a therapeutic against, the progression of RA is often avoided due to fear of worsening RA pathology. We introduce the K/BxN mouse as an RA model to study both myocardial and skeletal muscle dysfunction. We show that endurance exercise can improve joint, cardiac, and skeletal muscle function in K/BxN mice, suggesting exercise may be beneficial for patients with RA.

Women with COPD from biomass smoke have reduced serum levels of biomarkers of angiogenesis and cancer, with EGFR predominating, compared to women with COPD from smoking

The main causes of COPD are smoking (COPD-TS) and exposure to biomass smoke (COPD-BS), considered as different phenotypes. The association of COPD-TS with lung cancer (LC) is well established, but not in COPD-BS. Thus, we studied the serum concentration of cytokines that participate in inflammation, angiogenesis, and tumor progression, used frequently as LC biomarkers, in women with COPD-BS compared with COPD-TS (n = 70). Clinical and physiological characteristics and the serum concentration (multiplex immunoassay) of 16 cytokines were evaluated. The analysis revealed that women with COPD-BS were shorter and older, and had lower concentrations of 12 serum cytokines: 6 proinflammatory and angiogenic IL-6Rα, PECAM-1, leptin, osteopontin, prolactin, and follistatin; and 6 that participate in angiogenesis and in tumor progression FGF-2, HGF, sVEGFR-2, sHER2/neu, sTIE-2, G-CSF, and SCF. Notably, there was a significant increase in sEGFR in women with COPD-BS compared to women with COPD-TS. PDGF-AA/BB and sTIE-2 did not change. These findings suggest that women with COPD-BS have markedly decreased proinflammatory, angiogenic, and tumor progression potential, compared to women with COPD-TS, with sEGFR as the predominant mediator, which might reflect a differential pattern of inflammation in women exposed to BS, favoring the development of chronic bronchitis.

Dietary Energy Modulation and Autophagy: Exploiting Metabolic Vulnerabilities to Starve Cancer

Cancer cells experience unique and dynamic shifts in their metabolic function in order to survive, proliferate, and evade growth inhibition in the resource-scarce tumor microenvironment. Therefore, identification of pharmacological agents with potential to reprogram cancer cell metabolism may improve clinical outcomes in cancer therapy. Cancer cells also often exhibit an increased dependence on the process known as autophagy, both for baseline survival and as a response to stressors such as chemotherapy or a decline in nutrient availability. There is evidence to suggest that this increased dependence on autophagy in cancer cells may be exploitable clinically by combining autophagy modulators with existing chemotherapies. In light of the increased metabolic rate in cancer cells, interest is growing in approaches aimed at "starving" cancer through dietary and pharmacologic interventions that reduce availability of nutrients and pro-growth hormonal signals known to promote cancer progression. Several dietary approaches, including chronic calorie restriction and multiple forms of fasting, have been investigated for their potential anti-cancer benefits, yielding promising results in animal models. Induction of autophagy in response to dietary energy restriction may underlie some of the observed benefit. However, while interventions based on dietary energy restriction have demonstrated safety in clinical trials, uncertainty remains regarding translation to humans as well as feasibility of achieving compliance due to the potential discomfort and weight loss that accompanies dietary restriction. Further induction of autophagy through dietary or pharmacologic metabolic reprogramming interventions may enhance the efficacy of autophagy inhibition in the context of adjuvant or neo-adjuvant chemotherapy. Nonetheless, it remains unclear whether therapeutic agents aimed at autophagy induction, autophagy inhibition, or both are a viable therapeutic strategy for improving cancer outcomes. This review discusses the literature available for the therapeutic potential of these approaches.

Interleukin-6: Molecule in the Intersection of Cancer, Ageing and COVID-19

Interleukin-6 (IL-6) is a cytokine with multifaceted effects playing a remarkable role in the initiation of the immune response. The increased level of this cytokine in the elderly seems to be associated with the chronic inflammatory setting of the microenvironment in aged individuals. IL-6 also represents one of the main signals in communication between cancer cells and their non-malignant neighbours within the tumour niche. IL-6 also participates in the development of a premetastatic niche and in the adjustment of the metabolism in terminal-stage patients suffering from a malignant disease. IL-6 is a fundamental factor of the cytokine storm in patients with severe COVID-19, where it is responsible for the fatal outcome of the disease. A better understanding of the role of IL-6 under physiological as well as pathological conditions and the preparation of new strategies for the therapeutic control of the IL-6 axis may help to manage the problems associated with the elderly, cancer, and serious viral infections.

Adipose depot gene expression and intelectin-1 in the metabolic response to cancer and cachexia

BACKGROUND

Cancer cachexia is a poorly understood metabolic consequence of cancer. During cachexia, different adipose depots demonstrate differential wasting rates. Animal models suggest adipose tissue may be a key driver of muscle wasting through fat-muscle crosstalk, but human studies in this area are lacking. We performed global gene expression profiling of visceral (VAT) and subcutaneous (SAT) adipose from weight stable and cachectic cancer patients and healthy controls.

METHODS

Cachexia was defined as >2% weight loss plus low computed tomography-muscularity. Biopsies of SAT and VAT were taken from patients undergoing resection for oesophago-gastric cancer, and healthy controls (n = 16 and 8 respectively). RNA was isolated and reverse transcribed. cDNA was hybridised to the Affymetrix Clariom S microarray and data analysed using R/Bioconductor. Differential expression of genes was assessed using empirical Bayes and moderated-t-statistic approaches. Category enrichment analysis was used with a tissue-specific background to examine the biological context of differentially expressed genes. Selected differentially regulated genes were validated by qPCR. Enzyme-linked immunosorbent assay (ELISA) for intelectin-1 was performed on all VAT samples. The previously-described cohort plus 12 additional patients from each group also had plasma I = intelectin-1 ELISA carried out.

RESULTS

In VAT vs. SAT comparisons, there were 2101, 1722, and 1659 significantly regulated genes in the cachectic, weight stable, and control groups, respectively. There were 2200 significantly regulated genes from VAT in cachectic patients compared with controls. Genes involving inflammation were enriched in cancer and control VAT vs. SAT, although different genes contributed to enrichment in each group. Energy metabolism, fat browning (e.g. uncoupling protein 1), and adipogenesis genes were down-regulated in cancer VAT (P = 0.043, P = 5.4 × 10^-6 and P = 1 × 10^-6 respectively). The gene showing the largest difference in expression was ITLN1, the gene that encodes for intelectin-1 (false discovery rate-corrected P = 0.0001), a novel adipocytokine associated with weight loss in other contexts.

CONCLUSIONS

SAT and VAT have unique gene expression signatures in cancer and cachexia. VAT is metabolically active in cancer, and intelectin-1 may be a target for therapeutic manipulation. VAT may play a fundamental role in cachexia, but the down-regulation of energy metabolism genes implies a limited role for fat browning in cachectic patients, in contrast to pre-clinical models.

Asprosin is associated with anorexia and body fat mass in cancer patients

PURPOSE

Increasing evidence suggests that many adipokines are involved in cancer-related anorexia and cachexia syndrome (CACS), although the underlying mechanism remains to be clarify. Asprosin is a new peptide hormone mainly secreted by white adipose tissues that can increase appetite and body weight. In this cross-sectional study, we tested whether asprosin may intervene in the development of CACS.

METHODS

The fasting plasma asprosin levels were determined via enzyme-linked immune-sorbent assay. Anorexia was determined using the anorexia/cachexia subscale (A/CS) of the functional assessment of anorexia/cachexia therapy (FAACT) questionnaire. The body composition was assessed using bioelectrical impedance analysis. The association of plasma asprosin with anorexia, cachexia, and nutritional status was analyzed.

RESULTS

One hundred twenty treatment-naïve patients with pathological confirmed gastrointestinal or lung cancer and 14 mild gastritis patients were recruited. We found no significant difference in asprosin levels between subgroups of patients by age, sex, cancer types or stage. Correlation analysis suggested that asprosin levels were positively associated with body fat mass (r = 0.248, p = 0.043). No correlations were found between asprosin levels and hemoglobin, white blood cell count, blood platelet count, albumin, C-reactive protein, glucose, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, body mass index, body fat percentage, protein, skeletal muscle, muscle mass, lean body mass, and basal metabolic rate. Furthermore, asprosin levels were not significantly different between patients with or without cachexia. However, patients with anorexia had significantly lower asprosin levels compared with patients without anorexia. No significant difference in asprosin levels between gastritis and gastric cancer patients. Similarly, no significant change of asprosin levels occurred postoperatively in 10 gastric cancer patients.

CONCLUSIONS

Patients with anorexia had significantly lower asprosin levels compared with patients without anorexia. We therefore speculated that asprosin might intervene in the development of cancer anorexia and serve as a potential therapeutic target.

Regulatory Role of the Transcription Factor Twist1 in Cancer-Associated Muscle Cachexia

Muscle cachexia is a catabolic response, usually takes place in various fatal diseases, such as sepsis, burn injury, and chronic kidney disease. Muscle cachexia is also a common co-morbidity seen in the vast majority of advanced cancer patients, often associated with low quality of life and death due to general organ dysfunction. The triggering events and underlying molecular mechanisms of muscle wasting are not yet clearly defined. Our recent study has shown that the ectopic expression of Twist1 in muscle progenitor cells is sufficient to drive muscle structural protein breakdown and attendant muscle atrophy, reminiscent of muscle cachexia. Intriguingly, muscle Twist1 expression is highly induced in cachectic muscles from several mouse models of pancreatic ductal adenocarcinoma (PDAC), raising the interesting possibility that Twist1 may mediate PDAC-driven muscle cachexia. Along these lines, both genetic and pharmacological inactivation of Twist1 function was highly significant at protecting against cancer cachexia, which translated into a significant survival benefit in the experimental PDAC animals. From a translational perspective, elevated expression of Twist1 is also detected in cancer patients with severe muscle wasting, implicating a role of Twist1 in cancer cachexia, and further providing a possible target for therapeutic attenuation of cachexia to improve cancer patient survival. In this article, we will briefly summarize how Twist1 acts as a master regulator of tumor-induced cachexia, and discuss the relevance of our findings to muscle wasting diseases in general. The mechanism of decreased muscle mass in various catabolic conditions is thought to rely on similar pathways, and, therefore, Twist1-induced cancer cachexia may benefit diverse groups of patients with clinical complications associated with loss of muscle mass and functions, beyond the expected benefits for cancer patients.

Role of Interleukin-6 in Lung Complications in Patients With COVID-19: Therapeutic Implications

COVID-19 is viral respiratory infection with frequently fatal lung complications in the elderly or in people with serious comorbidities. Lung destruction appears to be associated with a cytokine storm related to an increased level of interleukin-6 (IL6). Therapeutic targeting of the interleukin-6 signaling pathway can attenuate such a cytokine storm and can be beneficial for patients with COVID-19 in danger of pulmonary failure. This article demonstrates the importance of IL6 in progression of disease and the possibility of inhibition of IL6 signaling in COVID-19 therapy.

E0771 and 4T1 murine breast cancer cells and interleukin 6 alter gene expression patterns but do not induce browning in cultured white adipocytes

Breast cancer remains a substantial clinical problem worldwide, and cancer-associated cachexia is a condition associated with poor prognosis in this and other malignancies. Adipose tissue is involved in the development and progression of cancer-associated cachexia, but its various roles and mechanisms of action are not completely defined, especially as it relates to breast cancer. Interleukin 6 has been implicated in several mechanisms contributing to increased breast cancer tumorigenesis, as well as a net-negative energy balance and cancer-associated cachexia via adipose tissue remodeling in other models of cancer; however, its potential role in breast cancer-associated white adipose browning has not been explored. In this study, we demonstrate localized white adipose tissue browning in a spontaneous model of murine mammary cancer. We then used an in vitro murine adipocyte culture system with the E0771 and 4T1 cell lines as models of breast cancer. We demonstrate that while the E0771 and 4T1 secretomes and cross-talk with white adipocytes alter white adipocyte mRNA expression, they do not directly induce white adipocyte browning. Additionally, we show that neither exogenous administration of interleukin 6 alone or with its soluble receptor directly induce white adipocyte browning. Together, these results demonstrate that neither the E0771 or 4T1 murine breast cancer cell lines, nor interleukin 6, directly cause browning of cultured white adipocytes. This suggests that their roles in adipose tissue remodeling are more complex and indirect in nature.

Novel molecular targets of muscle wasting in cancer patients

PURPOSE OF REVIEW

Cancer-associated muscle wasting affects many patients and leads to reduced patient function, decreased quality of life and poor responses to surgical and oncological treatments. Despite advancements in the understanding of its pathophysiology, no current treatment or accepted strategy for successful management exists. In this review, we provide an update on potential novel therapeutic targets in cancer cachexia.

RECENT FINDINGS

Recent research has focused on molecular mechanisms underlying cancer-associated muscle wasting, allowing identification of potential therapeutic targets and the development of several promising drugs. However, due to the multifactorial and patient-specific pathogenesis of cachexia, the demonstration of a measurable and meaningful clinical effect in randomized controlled trials has proven difficult. Potential novel targets such as circulating macrophage inhibitory cytokine 1/growth differentiation factor 15 and ZRT/IRT-like protein 14 have shown relevance in animal models, but their therapeutic manipulation has yet to be translated to patients. Increasing evidence has suggested that a single therapy may not be successful and a targeted, multimodal approach is required.

SUMMARY

The management of cancer-associated muscle wasting is complex. Future clinical trials should focus on early multimodal therapeutic interventions involving targeted therapies, with careful deliberation of chosen nutritional and functional outcomes.

Modulation of the IL-6-Signaling Pathway in Liver Cells by miRNAs Targeting gp130, JAK1, and/or STAT3

Interleukin-6 (IL-6)-type cytokines share the common receptor glycoprotein 130 (gp130), which activates a signaling cascade involving Janus kinases (JAKs) and signal transducer and activator of transcription (STAT) transcription factors. IL-6 and/or its signaling pathway is often deregulated in diseases, such as chronic liver diseases and cancer. Thus, the identification of compounds inhibiting this pathway is of interest for future targeted therapies. We established novel cellular screening systems based on a STAT-responsive reporter gene (Cypridina luciferase). Of a library containing 538 microRNA (miRNA) mimics, several miRNAs affected hyper-IL-6-induced luciferase activities. When focusing on candidate miRNAs specifically targeting 3′ UTRs of signaling molecules of this pathway, we identified, e.g., miR-3677-5p as a novel miRNA affecting protein expression of both STAT3 and JAK1, whereas miR-16-1-3p, miR-4473, and miR-520f-3p reduced gp130 surface expression. Interestingly, combination treatment with 2 or 3 miRNAs targeting gp130 or different signaling molecules of the pathway did not increase the inhibitory effects on phospho-STAT3 levels and STAT3 target gene expression compared to treatment with single mimics. Taken together, we identified a set of miRNAs of potential therapeutic value for cancer and inflammatory diseases, which directly target the expression of molecules within the IL-6-signaling pathway and can dampen inflammatory signal transduction.

The PD-L1- and IL6-mediated dampening of the IL27/STAT1 anticancer responses are prevented by α-PD-L1 or α-IL6 antibodies

Interleukin-27 (IL27) is a type-I cytokine of the IL6/IL12 family and is predominantly secreted by activated macrophages and dendritic cells. We show that IL27 induces STAT factor phosphorylation in cancerous cell lines of different tissue origin. IL27 leads to STAT1 phosphorylation and recapitulates an IFN-γ-like response in the microarray analyses, with up-regulation of genes involved in antiviral defense, antigen presentation, and immune suppression. Like IFN-γ, IL27 leads to an up-regulation of TAP2 and MHC-I proteins, which mediate increased tumor immune clearance. However, both cytokines also upregulate proteins such as PD-L1 (CD274) and IDO-1, which are associated with immune escape of cancer. Interestingly, differential expression of these genes was observed within the different cell lines and when comparing IL27 to IFN-γ. In coculture experiments of hepatocellular carcinoma (HCC) cells with peripheral blood mononuclear cells, pre-treatment of the HCC cells with IL27 resulted in lowered IL2 production by anti-CD3/-CD28 activated T-lymphocytes. Addition of anti-PD-L1 antibody, however, restored IL2 secretion. The levels of other T_H 1 cytokines were also enhanced or restored upon administration of anti-PD-L1. In addition, we show that the suppression of IL27 signaling by IL6-type cytokine pre-stimulation-mimicking a situation occurring, for example, in IL6-secreting tumors or in tumor inflammation-induced cachexia-can be antagonized by antibodies against IL6-type cytokines or their receptors. Therapeutically, the antitumor effects of IL27 (mediated, e.g., by increased antigen presentation) might thus be increased by combining IL27 with blocking antibodies against PD-L1 or/and IL6-type cytokines.