The pivotal role of cytokines in muscle wasting during cancer

Therapeutic Potential of Hydrogen-Rich Water on Muscle Atrophy Caused by Immobilization in a Mouse Model

Skeletal muscle atrophy is associated with poor quality of life and disability. Thus, finding a new strategy for the prevention and treatment of skeletal muscle atrophy is very crucial. This study aimed to investigate the therapeutic potential of hydrogen-rich water (HRW) on muscle atrophy in a unilateral hind limb immobilization model. Thirty-six male Balb/C mice were divided into control (without immobilization), atrophy, and atrophy + hydrogen-rich water (HRW). Unilateral hind limb immobilization was induced using a splint for 7 days (atrophy) and removed for 10 days (recovery). At the end of each phase, gastrocnemius and soleus muscle weight, limb grip strength, skeletal muscle histopathology, muscle fiber size, cross-section area (CSA), serum troponin I and skeletal muscle IL-6, TNF-α and Malondialdehyde (MDA), and mRNA expression of NF-κB, BAX and Beclin-1 were evaluated. Muscle weight and limb grip strength in the H2-treated group were significantly improved during the atrophy phase, and this improvement continued during the recovery period. Treatment by HRW increased CSA and muscle fiber size and reduced muscle fibrosis, serum troponin I, IL-6, TNF-α and MDA which was more prominent in the atrophy phase. These data suggest that HRW could improve muscle atrophy in an immobilized condition and could be considered a new strategy during rehabilitation.

Sarcopenia remaining after intensive nutritional feeding support could be a criterion for the selection of patients for surgery for oesogastric junction adenocarcinoma

BACKGROUND

Sarcopenia is recognized as a negative prognostic factor in several cancers. The aim of this study was to investigate the impact of nutritional support with feeding jejunostomy (FJ) on the occurrence of sarcopenia and how it may affect postoperative short-term outcomes and long-term survival outcomes in patients undergoing esophagectomy for oesogastric junction adenocarcinoma (OJA).

METHODS

Patients with OJA were included. The presence of sarcopenia was determined using cutoff values of the total cross-sectional muscle tissue measured on CT scan. We analyzed risk factors for sarcopenia occurrence and the impact of preoperative sarcopenia on postoperative results, overall survival and disease-free survival.

RESULTS

A total of 124 patients were eligible for analysis. Ninety-one patients underwent surgery after chemotherapy, and 72 of them received preoperative FJ. Among the 91 patients, 21 patients (23.0%) were sarcopenic after preoperative chemotherapy. Multivariate analysis showed that FJ is a protective factor against sarcopenia occurrence. Overall survival was significantly different between sarcopenic and nonsarcopenic patients (median survival = 33.7 vs. 58.6 months, respectively, p = 0.04), and sarcopenia occurrence was an independent risk factor for overall survival in patients who underwent surgery (HR = 3.02; CI 95% 1.55-5.9; p < 0.005). Subgroup analyses showed no differences in overall survival between patients who presented sarcopenia despite nutritional prehabilitation with a FJ and patients excluded from surgery in palliative situations (median survival = 21.9 vs. 17.2 months, respectively, p = 0.46).

CONCLUSION

The persistence of sarcopenia after preoperative chemotherapy despite renutrition with FJ could be a selection factor to propose curative surgery for OJA.

High Systemic Immune Inflammation Index Is Associated With Low Skeletal Muscle Quantity in Resectable Pancreatic Ductal Adenocarcinoma

Background and Aims

Failing immune surveillance in pancreatic ductal adenocarcinoma (PDAC) is related to poor prognosis. PDAC is also characterized by its substantial alterations to patients' body composition. Therefore, we investigated associations between the host systemic immune inflammation response and body composition in patients with resected PDAC.

Methods

Patients who underwent a pancreatectomy for PDAC between 2004 and 2016 in two tertiary referral centers were included. Skeletal muscle mass quantity and muscle attenuation, as well as subcutaneous and visceral adipose tissue at the time of diagnosis, were determined by CT imaging measured transversely at the third lumbar vertebra level. Baseline clinicopathological characteristics, laboratory values including the systemic immune inflammation index (SIII), postoperative, and survival outcomes were collected.

Results

A total of 415 patients were included, and low skeletal muscle mass quantity was found in 273 (65.7%) patients. Of the body composition indices, only low skeletal muscle mass quantity was independently associated with a high (≥900) SIII (OR 7.37, 95% CI 2.31-23.5, p=0.001). The SIII was independently associated with disease-free survival (HR 1.86, 95% CI 1.12-3.04), and cancer-specific survival (HR 2.21, 95% CI 1.33-3.67). None of the body composition indices were associated with survival outcomes.

Conclusion

This study showed a strong association between preoperative low skeletal muscle mass quantity and elevated host systemic immune inflammation in patients with resected PDAC. Understanding how systemic inflammation may contribute to changes in body composition or whether reversing these changes may affect the host systemic immune inflammation response could expose new therapeutic possibilities for improving patients' survival outcomes.

Impact of Sarcopenia and Inflammation on Patients with Advanced Non-Small Cell Lung Cancer (NCSCL) Treated with Immune Checkpoint Inhibitors (ICIs): A Prospective Study

BACKGROUND

Sarcopenia is a condition characterized by loss of skeletal muscle mass associated with worse clinical outcomes in cancer patients. Data on sarcopenia in patients undergoing immune checkpoint inhibitors (ICI) therapy are still limited. The aim of this prospective observational study was to investigate the relationship between sarcopenia, ICI treatment response and immunological profile, in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Forty-seven stage IV NSCLC patient candidates for starting ICI, were enrolled from the Policlinico Umberto I outpatient Oncology. Patients underwent baseline blood test, inflammatory markers, cytokine assessment and body composition with dual-energy X-ray absorptiometry (DXA). Sarcopenia was defined with appendicular skeletal muscle mass over height² (ASM/heigh²).

RESULTS

Overall, 19/47 patients (40.4%) results were sarcopenic. Sarcopenic patients showed significantly shorter PFS than non-sarcopenic ones (20.3 weeks, 95% CI 7.5-33.1 vs. 61 weeks, 95% CI 22.5-99.4, p = 0.047). Specifically, they had an 8.1 times higher risk of progression disease (PD) than non-sarcopenic patients (OR 8.1, 95%, p = 0.011).

CONCLUSIONS

Sarcopenic patients showed worse PFS and had a higher risk of PD compared to non-sarcopenic ones. Therefore, sarcopenia may reflect the increased metabolic activity of more aggressive tumors, which involves systemic inflammation and muscle wasting and could be considered a negative predictive factor for ICI response.

Impact of neutrophil-lymphocyte ratio, Glasgow Prognostic Score, and postoperative decrease in psoas muscle index on recurrence after curative gastrectomy

Aim : We investigated whether preoperative or postoperative inflammatory markers and psoas muscle index (PMI), and their change after surgery, could predict postoperative recurrence in gastric cancer (GC). Methods : Thirty-five patients who underwent curative gastrectomy for pStage II and III GC were retrospectively reviewed. The relationship between neutrophil-lymphocyte ratio (NLR), prognostic nutritional index (PNI), Glasgow Prognostic Score (GPS), and PMI, as well as postoperative recurrence, was analyzed presurgery and at 6 months after surgery. Results : In the preoperative data, there was a significant association between postoperative recurrence and high NLR, low total protein, low albumin, low PNI, and high GPS. In the data from 6 months after surgery, there was a significant association between postoperative recurrence and high NLR, high C-reactive protein, and high GPS. The reduction in PMI at 6 months after surgery relative to preoperative data was significantly greater in the cases with recurrence than in those without recurrence. No patients whose PMI increased compared with presurgery had recurrence. Conclusions : The postoperative reduction in PMI at 6 months after surgery relative to presurgery could be a predictive marker of recurrence after curative gastrectomy for patients with pStage II and III GC. J. Med. Invest. 68 : 119-124, February, 2021.

Prognostic value of nutritional markers in nasopharyngeal carcinoma patients receiving intensity-modulated radiotherapy: a propensity score matching study

Purpose

To investigate the prognostic value of nutritional markers for survival in nasopharyngeal carcinoma (NPC) patients receiving intensity-modulated radiotherapy (IMRT), with or without chemotherapy.

Patients and methods

This retrospective study included 412 NPC patients who received IMRT-based treatment. Weight loss (WL) during treatment, hemoglobin level (Hb) and serum albumin level (Alb) before treatment were measured. The prognostic values of these markers for overall survival (OS), locoregional recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were analyzed using Kaplan-Meier method and Cox proportional hazards regression analysis. Propensity score matching was performed to reduce the effect of confounders.

Results

WL, Hb and Alb were significantly correlated with each other and inflammatory markers. Adjusted Cox regression analysis showed that critical weight loss (CWL) (WL≥5%) was an independent prognostic factor for OS (HR: 2.399, 95% CI: 1.267-4.540, P=0.007) and LRFS (HR: 2.041, 95% CI: 1.052-3.960, P=0.035), while low pretreatment Hb was independently associated with poor DMFS (HR: 2.031, 95% CI: 1.144-3.606, P=0.016). However, no significant correlation was found between Alb and survival in our study cohort. The prognostic value of these markers was further confirmed in the propensity-matched analysis.

Conclusion

CWL, Hb and Alb have a significant impact on survival in NPC patients undergoing IMRT. They can be utilized in combination with conventional staging system to predict the prognosis of NPC patients treated with IMRT.

The Relationship between Sarcopenia and Systemic Inflammatory Response for Cancer Cachexia in Small Cell Lung Cancer

BACKGROUND

The prognostic significance of sarcopenia, an important component of cancer cachexia, has been demonstrated in oncologic patients. Catabolic drivers have been suggested to be key features of cancer cachexia.

OBJECTIVE

To determine the relationship between systemic inflammatory markers and CT-determined muscle mass in patients with SCLC.

METHODS

Cross-sectional muscle areas were evaluated at the level of the third lumbar vertebra (L3) using baseline CT images in 186 SCLC patients. Sarcopenia was defined as a L3 muscle index (L3MI, muscle area at L3/height2) of < 55 cm2/m2 for men and of < 39 cm2/m2 for women. Systemic inflammatory markers investigated included serum white blood cell count (WBC), neutrophil: lymphocyte ratio (NLR), C-reactive protein (CRP), and albumin.

RESULTS

Mean L3MI was 47.9 ± 9.7 cm2/m2 for men and 41.6 ± 7.0 cm2/m2 for women. Sarcopenia was present in 128 patients (68.8%), and sarcopenic patients had significant serum lymphocyte counts and albumin levels (p = 0.002 and 0.041, respectively), and higher NLRs and CRP levels (p = 0.011 and 0.026) than non-sarcopenic patients. Multivariable analysis revealed that CRP independently predicted L3MI (β = -0.208; 95% CI, -0.415 to -0.002; p = 0.048), along with gender and BMI (p values < 0.001) and performance status (p = 0.010).

CONCLUSION

The present study confirms a significant linear relationship exists between CT-determined muscle mass and CRP in SCLC patients. This association might provide a better understanding of the mechanism of cancer cachexia.

Preventive effects of electrical stimulation on inflammation-induced muscle mitochondrial dysfunction

Cachexia is a complex metabolic syndrome associated with underlying chronic diseases and is characterized by the overexpression of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), which impair muscle oxidative metabolism. We hypothesized that electrical stimulation (ES) would prevent decrement in muscle oxidative metabolism by suppressing the phosphorylation of p38 MAPK, a critical regulator of inflammatory response. Therefore, the purpose of the present study was to verify the effects of ES on inflammatory-induced decrement of oxidative metabolism in mice tibialis anterior muscles. ICR mice were randomly divided into three groups: control, lipopolysaccharide (LPS) injection for 4days, and LPS injection plus ES (LPS+ES). Cachexia was induced in the animals in the LPS groups via LPS injection (10mg/kg body weight/day, i.p.) during the intervention period. The animals in the LPS+ES group were stimulated electrically (carrier frequency, 2500Hz; modulation frequency, 100Hz; duration, 240s/day; type of contraction, isometric) during the intervention period. LPS injection resulted in decreased body and muscle wet weight and increased expression of TNF-α in plasma and skeletal muscle. In addition, LPS injection decreased indicators of mitochondrial function such as succinate dehydrogenase (SDH) and citrate synthase (CS) activity as well as the expression of PGC-1ɑ, and increased the phosphorylation of p38 MAPK. On the other hand, the intervention of ES attenuated the changes in muscle wet weight, SDH activity, CS activity, p38 MAPK, and PGC-1ɑ. These results suggest that ES could prevent decrement in muscle oxidative metabolism induced by pro-inflammatory cytokines in cachexia.

A Key Role for Leukemia Inhibitory Factor in C26 Cancer Cachexia

Cachexia is an exacerbating event in many types of cancer that is strongly associated with a poor prognosis. We have identified cytokine, signaling, and transcription factors that are required for cachexia in the mouse C26 colon carcinoma model of cancer. C2C12 myotubes treated with conditioned medium from C26 cancer cells induced atrophy and activated a STAT-dependent reporter gene but not reporter genes dependent on SMAD, FOXO, C/EBP, NF-κB, or AP-1. Of the gp130 family members IL-11, IL-6, oncostatin M (OSM), and leukemia inhibitory factor (LIF), only OSM and LIF were sufficient to activate the STAT reporter in myotubes. LIF was elevated in C26 conditioned medium (CM), but IL-6, OSM, TNFα, and myostatin were not. A LIF-blocking antibody abolished C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and myotube atrophy but blocking antibodies to IL-6 or OSM did not. JAK2 inhibitors also blocked C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and atrophy in myotubes. LIF at levels found in the C26 CM was sufficient for STAT reporter activation and atrophy in myotubes. In vivo, an increase in serum LIF preceded the increase in IL-6 in mice with C26 tumors. Overexpression of a dominant negative Stat3Cβ-EGFP gene in myotubes and in mouse muscle blocked the atrophy caused by C26 CM or C26 tumors, respectively. Taken together, these data support an important role of LIF-JAK2-STAT3 in C26 cachexia and point to a therapeutic approach for at least some types of cancer cachexia.

C26 cancer-induced muscle wasting is IKKβ-dependent and NF-kappaB-independent

Existing data suggest that NF-kappaB signaling is a key regulator of cancer-induced skeletal muscle wasting. However, identification of the components of this signaling pathway and of the NF-κB transcription factors that regulate wasting is far from complete. In muscles of C26 tumor bearing mice, overexpression of dominant negative (d.n.) IKKβ blocked muscle wasting by 69% and the IκBα-super repressor blocked wasting by 41%. In contrast, overexpression of d.n. IKKα or d.n. NIK did not block C26-induced wasting. Surprisingly, overexpression of d.n. p65 or d.n. c-Rel did not significantly affect muscle wasting. Genome-wide mRNA expression arrays showed upregulation of many genes previously implicated in muscle atrophy. To test if these upregulated genes were direct targets of NF-κB transcription factors, we compared genome-wide p65 binding to DNA in control and cachectic muscle using ChIP-sequencing. Bioinformatic analysis of ChIP-sequencing data from control and C26 muscles showed very little p65 binding to genes in cachexia and little to suggest that upregulated p65 binding influences the gene expression associated with muscle based cachexia. The p65 ChIP-seq data are consistent with our finding of no significant change in protein binding to an NF-κB oligonucleotide in a gel shift assay, no activation of a NF-κB-dependent reporter, and no effect of d.n.p65 overexpression in muscles of tumor bearing mice. Taken together, these data support the idea that although inhibition of IκBα, and particularly IKKβ, blocks cancer-induced wasting, the alternative NF-κB signaling pathway is not required. In addition, the downstream NF-κB transcription factors, p65 and c-Rel do not appear to regulate the transcriptional changes induced by the C26 tumor. These data are consistent with the growing body of literature showing that there are NF-κB-independent substrates of IKKβ and IκBα that regulate physiological processes.

Physiological characterization of a mouse model of cachexia in colorectal liver metastases

Loss of skeletal muscle mass and function (cachexia) is severe in patients with colorectal liver metastases because of the large increase in resting energy expenditure but remains understudied because of a lack of suitable preclinical models. Our aim was to characterize a novel preclinical model of cachexia in colorectal liver metastases. We tested the hypothesis that mice with colorectal liver metastases would exhibit cachexia, as evidenced by a reduction in liver-free body mass, muscle mass, and physiological impairment. Twelve-week-old male CBA mice received an intrasplenic injection of Ringer solution (sham) or murine colorectal cancer cells (MoCR) to induce colorectal liver metastases. At end-point (20-29 days), the livers of MoCR mice were infiltrated completely with metastases, and MoCR mice had reduced liver-free body mass, muscle mass, and epididymal fat mass compared with sham controls (P < 0.03). MoCR mice exhibited impaired rotarod performance and grip strength (P < 0.03). Histochemical analyses of tibialis anterior muscles from MoCR mice revealed muscle fiber atrophy and reduced oxidative enzyme activity (P < 0.001). Adipose tissue remodeling was evident in MoCR mice, with reduced adipocyte diameter and greater infiltration of nonadipocyte tissue (P < 0.05). These findings reveal the MoCR mouse model exhibits significant cachexia and is a suitable preclinical model of cachexia in colorectal liver metastases. This model should be used for identifying effective treatments for cachexia to improve quality of life and reduce mortality in patients with colorectal liver metastases.

Osteoporosis in chronic inflammatory disease: the role of malnutrition

Osteoporosis is a metabolic bone disorder affecting million of people worldwide. Increased understanding of bone disease has led to a greater recognition of factors affecting bones, and consequently many secondary causes of osteoporosis were demonstrated. In this study, we aim to explore possible causes of bone loss and fractures in subjects affected by chronic inflammatory disease and to suggest new targets for intervention. In fact several studies, evaluated to perform this study, suggest that the patients with chronic inflammatory disease could be at high risk for fractures due to bone loss as consequence of malnutrition, caused by inflammation and hormonal change. Consequently, some actions could derive from the considerations of these mechanisms: a change in actual approach of chronic patients, that may include the investigation on the possible presence of osteoporosis, as well as further research on this topic to find a better therapy to prevent osteoporosis considering all the mechanisms described.

Cancer cachexia and anabolic interventions: a case report

BACKGROUND

Standard-of-care (SOC) cancer treatments are primarily aimed at reducing size and progression of a tumor. There is a need for successful supplemental anabolic therapies to combat cancer cachexia in addition to these SOC treatment modalities. Anabolic interventions, including testosterone and amino acid supplements, may be beneficial in reducing and/or reversing muscle wasting in these patient populations.

METHODS

A 48-year-old Caucasian female with recurrent cervical cancer was scheduled to receive three 21-day cycles of cisplatin and topetecan chemotherapy. She qualified, consented, and enrolled into a blinded interventional pilot study where she received daily whey protein (10 g, three times per day with meals) and a weekly injection of testosterone enanthate (100 mg intramuscular) before and during the SOC chemotherapy treatment period. Body composition, serum inflammatory markers, mixed muscle protein synthesis and breakdown rates, physical function, fatigue, and quality of life were assessed before and after the intervention period.

RESULTS

Body composition, as assessed by an increase in body weight and lean body mass and reduction in fat mass; physical function; fatigue; and quality of life each improved across the entire intervention period despite general increases in inflammatory markers and no improvements in muscle protein turnover towards the end of the intervention.

CONCLUSIONS

Concomitant treatment of oral amino acids and testosterone may be a viable therapeutic option for fighting cachexia and improving body composition and quality of life during chemotherapeutic treatment of recurrent cervical cancer. These positive outcomes may be attainable over time despite overall poor inflammatory status.

The role of thalidomide and placebo for the treatment of cancer-related anorexia-cachexia symptoms: results of a double-blind placebo-controlled randomized study

OBJECTIVES

To determine the effects of thalidomide and placebo on anorexia-cachexia and its related symptoms, body composition, resting metabolic rate, and serum cytokines and their receptors in patients with advanced cancer.

METHODS

Included in the study were patients with advanced cancer with weight loss greater than 5% in 6 months and who reported anorexia, fatigue, and one of the following: anxiety, depression, or sleep disturbances. Patients on chemotherapy within 2 weeks prior or during the study were excluded from the study. Patients were randomly assigned to either 100 mg thalidomide or placebo once a day for 14 days. The Edmonton Symptom Assessment Scale (ESAS), Functional Assessment of Anorexia/Cachexia Therapy (FAACT), Functional Assessment of Cancer Illness Therapy (FACIT-F), Hospital Anxiety Depression Scale (HADS) Pittsburgh Sleep Quality Index (PSQI) were utilized, and in addition body composition, Resting Energy Expenditure (REE), and serum cytokine levels were assessed.

RESULTS

Of the 31 patients entered in the study, 15 were assigned to the thalidomide group and 16 to the placebo group. However only 21/31 patients were able to complete the study. Compared with their baseline values, both the thalidomide and the placebo groups showed significant reduction in cytokines. Tumor necrosis factor (TNF)-α (p=0.04) and its receptors TNFR1 (p=0.04), TNFR2 (p=0.04), and interleukin (IL)-8 (p=0.04) were statistically significant in the thalidomide group. In the placebo group, TNF-α (p=0.008), TNFR1 (p=0.005), TNFR2 (p=0.005), IL-RA (p=0.005), IL-6 (p=0.005), and IL-8 (p=0.005) were statistically significant. However, improvement in these symptoms and cytokine levels were not significantly different in the thalidomide group compared with the placebo group. None of the patients withdrew from the study because of toxicity of either thalidomide or placebo.

CONCLUSIONS

Based on the poor accrual rate and attrition observed in this study, it is important that future research on thalidomide as a treatment for cancer-related anorexia-cachexia symptoms (ACS) in patients with advanced cancer use less stringent entry criteria and less exhaustive outcome measures.

Anti-inflammatory therapies in cancer cachexia

Disease progression in cancer is dependent on the complex interaction between the tumor and the host inflammatory response. Indeed, both the tumor and the patient produce cytokines that act on multiple target sites such as bone marrow, myocytes, hepatocytes, adipocytes, endothelial cells and neurons, where they produce a complex cascade of biological responses leading to the wasting associated with cachexia. The cytokines that have been involved in this cachectic response are TNF-alpha, IL-1, IL-6 and interferon-gamma. Interestingly, these cytokines share the same metabolic effects and their activities are closely interrelated. In many cases these cytokines exhibit synergic effects when administered together. Therefore, therapeutic strategies - either nutritional or pharmacological - have been based on either blocking their synthesis or their action.

T-cell protein tyrosine phosphatase is a key regulator in immune cell signaling: lessons from the knockout mouse model and implications in human disease

The immune system requires for its proper ontogeny, differentiation, and maintenance the function of several tyrosine kinases and adapters that create and modify tyrosine phosphorylation sites. Tyrosine phosphorylation is a crucial protein modification in immune cell signaling and can be reversed by protein tyrosine phosphatases (PTPs). Much progress has been made in identifying and understanding PTP function in the immune system. In this review, we present one of these proteins, named T-cell PTPs (TC-PTP) (gene name PTPN2), a classical, non-receptor PTP that is ubiquitously expressed with particularly high expression in hematopoietic tissues. TC-PTP is remarkable not only by the fact that it appears to influence most, if not all, cells involved in the development of the immune system, from stem cells to differentiated lineages, but also recent findings have positioned it at the core of several human diseases from autoimmune disease to cancer.

Prototypical anti-inflammatory cytokine IL-10 prevents loss of IGF-I-induced myogenin protein expression caused by IL-1beta

Prolonged and excessive inflammation is implicated in resistance to the biological actions of IGF-I and contributes to the pathophysiology of neurodegenerative, metabolic, and muscle-wasting disorders. IL-10 is a critical anti-inflammatory cytokine that restrains inflammatory responses in macrophages and T cells by inhibiting cytokine and chemokine synthesis and reducing expression of their receptors. Here we demonstrate that IL-10 plays a protective role in nonhematopoietic cells by suppressing the ability of exogenous IL-1beta to inhibit IGF-I-induced myogenin and myosin heavy chain expression in myoblasts. This action of IL-10 is not caused by impairment of IL-1beta-induced synthesis of IL-6 or the ability of IL-1beta to activate two members of the MAPK family, ERK1/2 and p38. Instead, this newly defined protective role of IL-10 occurs by specific reversal of IL-1beta activation of the JNK kinase pathway. IL-10 blocks IL-1beta-induced phosphorylation of JNK, but not ERK1/2 or p38, indicating that only the JNK component of the IL-1beta-induced MAPK signaling pathway is targeted by IL-10. This conclusion is supported by the finding that a specific JNK inhibitor acts similarly to IL-10 to restore IGF-I-induced myogenin expression, which is suppressed by IL-1beta. Collectively, these data demonstrate that IL-10 acts in a novel, nonclassical, protective manner in nonhematopoietic cells to inhibit the IL-1beta receptor-induced JNK kinase pathway, resulting in prevention of IGF-I resistance.

Combination of recombinant human growth hormone and propranolol decreases hypermetabolism and inflammation in severely burned children

OBJECTIVE

Recombinant human growth hormone (rhGH) is a salutary modulator of posttraumatic metabolic responses. However, rhGH administration is associated with deleterious side effects, such as hyperglycemia, increased free fatty acids, and triglycerides, which limit its use. Administration of beta-blocker attenuates cardiac work and resting energy expenditure after severe thermal injury and improves fat metabolism and insulin sensitivity. Therefore, the combination of rhGH plus propranolol appears ideal. The aim of the present study was to determine whether rhGH plus propranolol improves hypermetabolism and the inflammatory and acute phase response after severe burn without causing adverse side effects.

DESIGN

Prospective randomized control trial.

SETTING

Shriners Hospitals for Children.

PATIENTS

Fifteen pediatric patients with burns > 40% total body surface area, 0.1-16 yrs of age, admitted within 7 days after burn. Fifteen children were matched for burn size, age, gender, inhalation injury, and infection and served as controls.

INTERVENTIONS

Patients in the experimental group received rhGH (0.2 mg/kg/day) and propranolol (to decrease heart rate by 15%) for > or = 15 days.

MEASUREMENTS AND MAIN RESULTS

Outcome measurements included resting energy expenditure, body composition, acute phase proteins, and cytokines. Both cohorts were similar in age, burn size, gender, and accompanying injuries. Percent predicted resting energy expenditure significantly decreased in patients receiving rhGH/propranolol (Delta -5% +/- 8%) compared with controls (Delta +35% +/- 20%) (p < .05). rhGH/propranolol administration significantly decreased serum C-reactive protein, cortisone, aspartate aminotransferase, alanine aminotransferase, free fatty acids, interleukin-6, interleukin-8, and macrophage inflammatory protein-1beta when compared with controls, while growth hormone/propranolol increased serum insulin-like growth factor-I, insulin-like growth factor binding protein-3, growth hormone, prealbumin, and interleukin-7 when compared with placebo (p < .05).

CONCLUSIONS

rhGH in combination with propranolol attenuates hypermetabolism and inflammation without the adverse side effects found with rhGH therapy alone.

Impact of weight loss on circulating IL-1, IL-6, IL-8, TNF-alpha, VEGF-A, VEGF-C and midkine in gastroesophageal cancer patients

OBJECTIVE

Proinflammatory cytokines are involved in cancer-related weight loss, but the involvement of VEGF-A, VEGF-C, IL-8 and midkine in gastroesophageal cancer patients remains unknown.

DESIGN AND METHODS

Serum IL-1, IL-6, IL-8, TNF-alpha, VEGF-A, VEGF-C, and midkine were evaluated in 96 cancer patients and 42 controls using ELISAs and were related to the occurrence of weight loss, patient's age, gender and BMI, cancer TNM status and blood cell counts.

RESULTS

All cytokines were elevated in cancer patients with further up-regulation of IL-6, IL-8, midkine and VEGF-A in cachexia. Underweight, midkine and VEGF-A were found independent indicators of weight loss. Primary tumor seems to be a major source of pro-cachectic cytokines, yet neutrophils and platelets also contribute to cytokine elevation.

CONCLUSIONS

IL-6 and IL-8, and probably midkine and VEGF-A, appear to participate in the development of cancer-related cachexia in gastroesophageal malignancies, although a detailed mechanism underlying cytokine involvement needs to be elucidated.

Experimental arthritis inhibits the insulin-like growth factor-I axis and induces muscle wasting through cyclooxygenase-2 activation

Chronic arthritis induces cachexia associated with an inhibition of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) system and an activation of the E3 ubiquitin-ligating enzymes muscle atrophy F-box (MAFbx) and muscle Ring finger 1 (MuRF1) in the skeletal muscle. The aim of this work was to study the role of cyclooxygenase (COX)-2 in chronic arthritis-induced cachexia. Arthritis was induced in rats by Freund's adjuvant injection, and the effects of two COX inhibitors (indomethacin, a nonspecific inhibitor, and meloxicam, a selective COX-2 inhibitor on pituitary GH and on liver and serum IGF-I levels) were tested. Arthritis decreased body weight gain and GH and liver IGF-I gene expression. In the arthritic rats, both inhibitors, indomethacin and meloxicam, prevented the inhibitory effect of arthritis on body weight gain. Indomethacin and meloxicam administration to arthritic rats increased pituitary GH and liver IGF-I mRNA as well as serum levels of IGF-I. These data suggest that induction of COX-2 during chronic inflammation is involved in the inhibition of the GH-IGF-I axis and in the body weight loss. In the gastrocnemius muscle, arthritis increased the gene expression of tumor necrosis factor (TNF)-alpha, the E3 ubiquitin-ligating enzymes MAFbx and MuRF1, as well as of IGF-I and IGF-binding protein-5 (IGFBP-5). Inhibition of COX-2 by meloxicam administration increased gastrocnemius weight and decreased MAFbx, MuRF1, TNF-alpha, and IGFBP-5 gene expression. In summary, our data indicate that chronic arthritis-induced cachexia and muscle wasting are mediated by the COX-2 pathway resulting in a decreased GH-IGF-I secretion and increased expression of MAFbx and MuRF1 mRNA.

TNF-related weak inducer of apoptosis (TWEAK) is a potent skeletal muscle-wasting cytokine

TWEAK cytokine has been implicated in several biological responses including inflammation, angiogenesis, and osteoclastogenesis. We have investigated the role of TWEAK in regulating skeletal muscle mass. Addition of soluble TWEAK protein to cultured myotubes reduced the mean myotube diameter and enhanced the degradation of specific muscle proteins such as CK and MyHCf. The effect of TWEAK on degradation of MyHCf was stronger than its structural homologue, TNF-alpha. TWEAK increased the ubiquitination of MyHCf and the transcript levels of atrogin-1 and MuRF1 ubiquitin ligases. TWEAK inhibited phosphorylation of Akt kinase and its downstream targets GSK-3beta, FOXO1, mTOR, and p70S6K. Furthermore, TWEAK increased the activation of NF-kappaB transcription factor in myotubes. Adenoviral-mediated overexpression of IkappaB alpha deltaN (a degradation-resistant mutant of NF-kappaB inhibitory protein IkappaB alpha) in myotubes blocked the TWEAK-induced degradation of MyHCf. Chronic administration of TWEAK in mice resulted in reduced body and skeletal muscle weight with an associated increase in the activity of ubiquitin-proteasome system and NF-kappaB. Finally, muscle-specific transgenic overexpression of TWEAK decreased the body and skeletal muscle weight in mice. Collectively, our data suggest that TWEAK induces skeletal muscle atrophy through inhibition of the PI3K/Akt signaling pathway and activation of the ubiquitin-proteasome and NF-kappaB systems.

Role for IκBα, but not c-Rel, in skeletal muscle atrophy

Skeletal muscle atrophy is associated with a marked and sustained activation of nuclear factor-κB (NF-κB) activity. Previous work showed that p50 is one of the NF-κB family members required for this activation and for muscle atrophy. In this work, we tested whether another NF-κB family member, c-Rel, is required for atrophy. Because endogenous inhibitory factor κBα (IκBα) was activated (i.e., decreased) at 3 and 7 days of muscle disuse (i.e., hindlimb unloading), we also tested if IκBα, which binds and retains Rel proteins in the cytosol, is required for atrophy and intermediates of the atrophy process. To do this, we electrotransferred a dominant negative IκBα (IκBαΔN) in soleus muscles, which were either unloaded or weight bearing. IκBαΔN expression abolished the unloading-induced increase in both NF-κB activation and total ubiquitinated protein. IκBαΔN inhibited unloading-induced fiber atrophy by 40%. The expression of certain genes known to be upregulated with atrophy were significantly inhibited by IκBαΔN expression during unloading, including MAFbx/atrogin-1, Nedd4, IEX, 4E-BP1, FOXO3a, and cathepsin L, suggesting these genes may be targets of NF-κB transcription factors. In contrast, c-Rel was not required for atrophy because the unloading-induced markers of atrophy were the same in c-rel−/−and wild-type mice. Thus IκBα degradation is required for the unloading-induced decrease in fiber size, the increase in protein ubiquitination, activation of NF-κB signaling, and the expression of specific atrophy genes, but c-Rel is not. These data represent a significant advance in our understanding of the role of NF-κB/IκB family members in skeletal muscle atrophy, and they provide new candidate NF-κB target genes for further study.

Interleukin-15 increases glucose uptake in skeletal muscle An antidiabetogenic effect of the cytokine

Previous studies have demonstrated that interleukin-15 (IL-15) has important anabolic effects on muscle protein metabolism. In the present investigation we have analysed the effects of IL-15 on glucose metabolism in skeletal muscle. Administration of a single dose of the cytokine (100 microg/kg body weight) resulted in a 32% increase on glucose uptake (as measured by the uptake of 2-deoxyglucose) in skeletal muscle. The effects observed on glucose uptake were direct since in vitro incubations of rat EDL muscles in the presence of the cytokine resulted in a 30% increase in glucose uptake. Similarly, IL-15 increased glucose uptake in C2C12 cell cultures, this being related with an increase in both glucose oxidation to CO2 and the incorporation into muscle lipid. The effects of the cytokine were associated with an increase in GLUT-4 mRNA, suggesting a higher effect in insulin sensitivity. In conclusion, the data presented here indicate that IL-15 facilitates glucose metabolism in skeletal muscle and, therefore, a possible role of the cytokine as an antidiabetogenic drug merits future investigations.

Paraneoplastic syndromes affecting the nervous system

The paraneoplastic neurologic disorders (PND) are a diverse group of diseases characterized by the presence of neurologic dysfunction in the setting of a remote cancer. PND can affect almost any part of the nervous system, and are most commonly associated with lung cancer (small cell) and gynecologic tumors. Laboratory studies have demonstrated that an autoimmune response links the neurologic disorder and the cancer, and established a model whereby the cancer is believed to initiate the syndrome by expressing a protein antigen normally expressed in the nervous system, leading to anti-tumor immune response followed by autoimmune neurologic symptoms. We review the currently known PND and their pathogenesis.

Cancer-Associated Cachexia and Underlying Biological Mechanisms

Cancer metastases (spread to distant organs from the primary tumor site) signify systemic, progressive, and essentially incurable malignant disease. Anorexia and wasting develop continuously throughout the course of incurable cancer. Overall, in Westernized countries nearly exactly half of current cancer diagnoses end in cure and the other half end in death; thus, cancer-associated cachexia has a high prevalence. The pathophysiology of cancer-associated cachexia has two principal components: a failure of food intake and a systemic hypermetabolism/hypercatabolism syndrome. The superimposed metabolic changes result in a rate of depletion of physiological reserves of energy and protein that is greater than would be expected based on the prevailing level of food intake. These features indicate a need for nutritional support, metabolic management, and a clear appreciation of the context of life-limiting illness.

Inhibitors of COX activity preserve muscle mass in mice bearing the Lewis lung carcinoma, but not the B16 melanoma

Tumor-induced skeletal muscle wasting (SMW) contributes to the fatigue and weakness experienced by persons with cancer cachexia. Tumor necrosis factor-alpha (TNFa) and cyclooxygenase (COX) activity have been implicated in SMW in some animal models of cancer cachexia. We report that indomethacin, a nonspecific inhibitor of COX, and NS398, a specific inhibitor of COX2, preserved muscle mass and reduced type 1 TNF receptors in muscles of mice bearing the Lewis lung carcinoma, but not in mice bearing the B16 melanoma. These data suggest that tumor-induced SMW can occur via a COX2-independent pathway. The COX2-dependent pathway may involve reducing the catabolic effects of TNFa in muscle. Further study is needed to understand the relationship between COX and SMW, and whether patients with cancer cachexia might benefit from COX inhibitors.

Conjugated linoleic acid preserves muscle mass in mice bearing the Lewis lung carcinoma, but not the B16 melanoma

Conjugated linoleic acid (CLA), which is found in dairy products, reduces synthesis of tumor necrosis factor-alpha (TNFa), a pro-inflammatory cytokine that plays a major role in tumor-induced skeletal muscle wasting (SMW). The B16 melanoma expresses TNFa mRNA, and induced SMW with no change in muscle levels of TNFa type 1 receptor (TNFR1) protein. A diet containing .5% CLA had no effect on SMW or TNFR1 in mice bearing B16 tumors. In contrast, the Lewis lung carcinoma expresses low levels of TNFa mRNA, induced SMW, and increased muscle levels of TNFR1. A diet containing .5% CLA reduced SMW, but had no effect on muscle levels of TNFR1. We conclude that that tumor-induced SMW can occur independent of muscle levels of TNFR1. Further study is needed before CLA can be tested in persons with cancer cachexia.

Peripheral administration of a melanocortin 4-receptor inverse agonist prevents loss of lean body mass in tumor-bearing mice

Cachexia affects many different chronically ill patient populations, including those with cancer. It results in loss of body weight, particularly of lean body mass (LBM), and is estimated to be responsible for over 20% of all cancer-related deaths. Currently, available drugs are ineffective, and new therapies are urgently needed. Melanocortin 4-receptor (MC4-R) blockade has been shown recently to be effective in preventing cancer cachexia in rodent models. In the present study, we have tested a MC4-R blocker, ML00253764 [2-{2-[2-(5-bromo-2-methoxyphenyl)-ethyl]-3-fluorophenyl}-4,5-dihydro-1H-imidazolium hydrochloride] (Vos et al., 2004), in vitro and in vivo. In membranes of human embryonic kidney 293 cells expressing human MC4-R, ML00253764 displaced [Nle(4), d-Phe(7)]-alpha-melanocyte-stimulating hormone binding with an IC(50) of 0.32 microM. At concentrations above 1 microM, ML00253764 decreased cAMP accumulation (maximal reduction of -20%) indicative of inverse agonist activity. ML00253764 was administered twice daily (15 mg/kg s.c.) for 13 days to C57BL6 mice bearing s.c. Lewis lung carcinoma tumors. Food intake and body weight were measured, and body composition was assessed using magnetic resonance relaxometry. ML00253764 stimulated light-phase food intake relative to vehicle-treated controls (p < 0.05), although no effect was observed on 24-h food intake. During the 21 days of the experiment, the LBM of tumor vehicle-treated mice decreased (p < 0.05). In contrast, the tumor-bearing mice treated with ML00253764 maintained their LBM. These data support the view that MC4-R blockade may be a suitable approach for the treatment of cancer cachexia and that MC4-R inverse agonists may have potential as drug candidates.