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Background: Although suggestive of dysregulated metabolism, the relationship between serum LDH level, phenotypic/aetiologic diagnostic Global Leadership Initiative on Malnutrition (GLIM) criteria and survival in patients with advanced cancer has yet to examined., Methods: Prospectively collected data from patients with advanced cancer, undergoing anti-cancer therapy with palliative intent, across nine sites in the UK and Ireland between 2011-2016, was retrospectively analysed. LDH values were grouped as <250/250-500/>500 Units/L. Relationships were examined using χ 2 test for linear-by-linear association and binary logistics regression analysis., Results: A total of 436 patients met the inclusion criteria. 46% (n = 200) were male and 59% (n = 259) were ≥65 years of age. The median serum LDH was 394 Units/L and 33.5% (n = 146) had an LDH > 500 Units/L. LDH was significantly associated with ECOG-PS (p < 0.001), NLR (p < 0.05), mGPS (p < 0.05) and 3-month survival (p < 0.001). LDH was significantly associated with 3-month survival independent of weight loss (p < 0.01), BMI (p < 0.05), skeletal muscle mass (p < 0.01), metastatic disease (p < 0.05), NLR (p < 0.05) and mGPS (p < 0.01)., Discussion: LDH was associated with performance status, systemic inflammation and survival in patients with advanced cancer. LDH measurement may be considered as an aetiologic criteria and become a potential therapeutic target in the treatment of cancer cachexia., (© 2022. The Author(s).)

Background: Cachexia is a metabolic disorder characterised by muscle wasting, diminished response to anti-cancer treatments and poor quality of life. Our objective was to identify blood-based biomarkers of cachexia in advanced cancer patients. Hence, we characterised the plasma cytokine and blood cell mRNA profiles of patients grouped in three cohorts: patients with cachexia, pre-cachexia (no cachexia but high CRP levels: ⩾ 5 mg l⁻¹) and no cachexia (no cachexia and CRP: < 5 mg l⁻¹).Methods: A total of 122 newly diagnosed cancer patients with seven cancer types were studied prior to their initial therapy. Plasma levels of 22 cytokines were quantified using the bio-plex technology. mRNAs isolated from whole blood and expression profiles were determined by the chip array technology and Ingenuity Pathway Analysis (IPA) software.Results: In comparison with non-cachectic individuals, both pre-cachectic and cachectic patients showed an increase (⩾ 1.5-folds) in mRNA expression of neutrophil-derived proteases (NDPs) and significantly elevated angiotensin II (Ang II) (P = 0.005 and P = 0.02, respectively), TGFβ1 (P = 0.042 and P < 0.0001, respectively) and CRP (both P < 0.0001) in the plasma. Moreover, cachectic patients displayed a significant increase in IL-6 (P = 0.005), IL-8 (P = 0.001) and absolute neutrophil counts (P = 0.007).Conclusions: Ang II, TGFβ1, CRP and NDP are blood biomarkers for cancer cachexia. These findings contribute to early diagnosis and prevention of cachexia. [ABSTRACT FROM AUTHOR]

Background:Cachexia in both mice and humans is associated with tumour production of a sulphated glycoprotein called proteolysis-inducing factor (PIF). In mice PIF binds with high affinity to a surface receptor in skeletal muscle, but little is known about the human receptor. This study compares the human PIF receptor with the murine.Methods:Human PIF was isolated from the G361 melanoma and murine PIF from the MAC16 colon adenocarcinoma. The human PIF receptor was isolated from human skeletal muscle myotubes. Protein synthesis and degradation induced by human and murine PIF was studied in human and murine skeletal muscle myotubes.Results:Both the human and murine PIF receptors showed the same immunoreactivity and Mr 40 000. Both murine and human PIF inhibited total protein synthesis and stimulated protein degradation in human and murine myotubes to about the same extent, and this was attenuated by a rabbit polyclonal antibody to the murine PIF receptor, but not by a non-specific rabbit antibody. Both murine and human PIF increased the activity of the ubiquitin-proteasome pathway in both human and murine myotubes, as evidenced by an increased 'chymotrypsin-like' enzyme activity, protein expression of the 20S and 19S proteasome subunits, and increased expression of the ubiquitin ligases MuRF1 and MAFbx, and this was also attenuated by the anti-mouse PIF receptor antibody.Conclusions:These results suggest that the murine and human PIF receptors are identical. [ABSTRACT FROM AUTHOR]

Background:Anorexia-cachexia is a common and severe cancer-related complication but the underlying mechanisms are largely unknown. Here, using a mouse model for tumour-induced anorexia-cachexia, we screened for proteins that are differentially expressed in the hypothalamus, the brain's metabolic control centre.Methods:The hypothalamus of tumour-bearing mice with implanted methylcholanthrene-induced sarcoma (MCG 101) displaying anorexia and their sham-implanted pair-fed or free-fed littermates was examined using two-dimensional electrophoresis (2-DE)-based comparative proteomics. Differentially expressed proteins were identified by liquid chromatography-tandem mass spectrometry.Results:The 2-DE data showed an increased expression of dynamin 1, hexokinase, pyruvate carboxylase, oxoglutarate dehydrogenase, and N-ethylmaleimide-sensitive factor in tumour-bearing mice, whereas heat-shock 70 kDa cognate protein, selenium-binding protein 1, and guanine nucleotide-binding protein Gα0 were downregulated. The expression of several of the identified proteins was similarly altered also in the caloric-restricted pair-fed mice, suggesting an involvement of these proteins in brain metabolic adaptation to restricted nutrient availability. However, the expression of dynamin 1, which is required for receptor internalisation, and of hexokinase, and pyruvate carboxylase were specifically changed in tumour-bearing mice with anorexia.Conclusion:The identified differentially expressed proteins may be new candidate molecules involved in the pathophysiology of tumour-induced anorexia-cachexia. [ABSTRACT FROM AUTHOR]

Background:Cancer cachexia is characterised by skeletal muscle wasting; however, potential for muscle anabolism in patients with advanced cancer is unproven.Methods:Quantitative analysis of computed tomography images for loss/gain of muscle in cholangiocarcinoma patients receiving selumetinib (AZD6244; ARRY-142886) in a Phase II study, compared with a separate standard therapy group. Selumetinib is an inhibitor of mitogen-activated protein/extracellular signal-regulated kinase and of interleukin-6 secretion, a putative mediator of muscle wasting.Results:Overall, 84.2% of patients gained muscle after initiating selumetinib; mean overall gain of total lumbar muscle cross-sectional area was 13.6 cm2/100 days (∼2.3 kg on a whole-body basis). Cholangiocarcinoma patients who began standard treatment were markedly catabolic, with overall muscle loss of −7.3 cm2/100 days (∼1.2 kg) and by contrast only 16.7% of these patients gained muscle.Conclusion:Our findings suggest that selumetinib promotes muscle gain in patients with cholangiocarcinoma. Specific mechanisms and relevance for cachexia therapy remain to be investigated. [ABSTRACT FROM AUTHOR]

Background: Cachexia has major impact on cancer patients' morbidity and mortality. Future development of cachexia treatment needs methods for early identification of patients at risk. The aim of the study was to validate nine single-nucleotide polymorphisms (SNPs) previously associated with cachexia, and to explore 182 other candidate SNPs with the potential to be involved in the pathophysiology.Method: A total of 1797 cancer patients, classified as either having severe cachexia, mild cachexia or no cachexia, were genotyped.Results: After allowing for multiple testing, there was no statistically significant association between any of the SNPs analysed and the cachexia groups. However, consistent with prior reports, two SNPs from the acylpeptide hydrolase (APEH) gene showed suggestive statistical significance (P=0.02; OR, 0.78).Conclusion: This study failed to detect any significant association between any of the SNPs analysed and cachexia; although two SNPs from the APEH gene had a trend towards significance. The APEH gene encodes the enzyme APEH, postulated to be important in the endpoint of the ubiquitin system and thus the breakdown of proteins into free amino acids. In cachexia, there is an extensive breakdown of muscle proteins and an increase in the production of acute phase proteins in the liver. [ABSTRACT FROM AUTHOR]

Background: Atrophy of skeletal muscle in cancer cachexia has been attributed to a tumour-produced highly glycosylated peptide called proteolysis-inducing factor (PIF). The action of PIF is mediated through a high-affinity membrane receptor in muscle. This study investigates the ability of peptides derived from the 20 N-terminal amino acids of the receptor to neutralise PIF action both in vitro and in vivo.Methods: Proteolysis-inducing factor was purified from the MAC16 tumour using an initial pronase digestion, followed by binding on DEAE cellulose, and the pronase was inactivated by heating to 80°C, before purification of the PIF using affinity chromatography. In vitro studies were carried out using C(2)C(12) murine myotubes, while in vivo studies employed mice bearing the cachexia-inducing MAC16 tumour.Results: The process resulted in almost a 23,000-fold purification of PIF, but with a recovery of only 0.004%. Both the D- and L-forms of the 20mer peptide attenuated PIF-induced protein degradation in vitro through the ubiquitin-proteosome proteolytic pathway and increased expression of myosin. In vivo studies showed that neither the D- nor the L-peptides significantly attenuated weight loss, although the D-peptide did show a tendency to increase lean body mass.Conclusion: These results suggest that the peptides may be too hydrophilic to be used as therapeutic agents, but confirm the importance of the receptor in the action of the PIF on muscle protein degradation. [ABSTRACT FROM AUTHOR]

Background: Profound loss of adipose tissue is a hallmark of cancer cachexia. Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is suggested as a candidate in lipid catabolism.Methods: In the first study, eight weight-stable and 17 cachectic cancer patients (weight loss 5% in previous 6 months) were recruited. Zinc-α2-glycoprotein mRNA and protein expression were assessed in subcutaneous adipose tissue (SAT), subcutaneous adipose tissue morphology was examined and serum ZAG concentrations were quantified. In the second cohort, ZAG release by SAT was determined in 18 weight-stable and 15 cachectic cancer patients. The effect of ZAG on lipolysis was evaluated in vitro.Results: Subcutaneous adipose tissue remodelling in cancer cachexia was evident through shrunken adipocytes with increased fibrosis. In cachectic cancer patients, ZAG mRNA was upregulated (2.7-fold, P=0.028) while leptin mRNA decreased (2.2-fold, P=0.018); serum ZAG levels were found to be unaffected. Zinc-α2-glycoprotein mRNA correlated positively with weight loss (r=0.51, P=0.01) and serum glycerol levels (r=0.57, P=0.003). Zinc-α2-glycoprotein release by SAT was also elevated in cachectic patients (1.5-fold, P=0.024) and correlated with weight loss (r=0.50, P=0.003). Recombinant ZAG stimulated lipolysis in human adipocytes.Conclusions: Zinc-α2-glycoprotein expression and secretion by adipose tissue is enhanced in cachectic cancer patients. Given its lipid-mobilising effect, ZAG may contribute to adipose atrophy associated with cancer cachexia in human beings. [ABSTRACT FROM AUTHOR]

Background: The regulatory gene pathways that accompany loss of adipose tissue in cancer cachexia are unknown and were explored using pangenomic transcriptome profiling.Methods: Global gene expression profiles of abdominal subcutaneous adipose tissue were studied in gastrointestinal cancer patients with (n=13) or without (n=14) cachexia.Results: Cachexia was accompanied by preferential loss of adipose tissue and decreased fat cell volume, but not number. Adipose tissue pathways regulating energy turnover were upregulated, whereas genes in pathways related to cell and tissue structure (cellular adhesion, extracellular matrix and actin cytoskeleton) were downregulated in cachectic patients. Transcriptional response elements for hepatic nuclear factor-4 (HNF4) were overrepresented in the promoters of extracellular matrix and adhesion molecule genes, and adipose HNF4 mRNA was downregulated in cachexia.Conclusions: Cancer cachexia is characterised by preferential loss of adipose tissue; muscle mass is less affected. Loss of adipose tissue is secondary to a decrease in adipocyte lipid content and associates with changes in the expression of genes that regulate energy turnover, cytoskeleton and extracellular matrix, which suggest high tissue remodelling. Changes in gene expression in cachexia are reciprocal to those observed in obesity, suggesting that regulation of fat mass at least partly corresponds to two sides of the same coin. [ABSTRACT FROM AUTHOR]

Background: D-myo-inositol-1,2,6-triphosphate (alpha-trinositol, AT) is a polyanionic molecule capable of chelating divalent metal ions with anti-tumour and anti-cachectic activity in a murine model.Methods: To investigate the role of zinc in this process, mice bearing cachexia-inducing MAC16 tumour were treated with AT, with or without concomitant administration of ZnSO(4).Results: At a dose of 40 mg kg(-1), AT effectively attenuated both weight loss and growth of the MAC16 tumour, and both effects were attenuated by co-administration of Zn(2+). The concentration of zinc in gastrocnemius muscle increased with increasing weight loss, whereas administration of AT decreased the levels of zinc in plasma, skeletal muscle and tumour, which were restored back to control values after administration of ZnSO(4).Conclusion: These results suggest that zinc is important in both tumour growth and cachexia in this animal model. [ABSTRACT FROM AUTHOR]

Background:Macrophage inhibitory cytokine-1(MIC-1) is a potential modulator of systemic inflammation and nutritional depletion, both of which are adverse prognostic factors in oesophago-gastric cancer (OGC).Methods:Plasma MIC-1, systemic inflammation (defined as plasma C-reactive protein (CRP) of 10 mg l–1 or modified Glasgow prognostic score (mGPS) of 1), and nutritional status were assessed in newly diagnosed OGC patients (n=293). Healthy volunteers (n=35) served as controls.Results:MIC-1 was elevated in patients (median=1371 pg ml–1; range 141–39 053) when compared with controls (median=377 pg ml–1; range 141–3786; P<0.001). Patients with gastric tumours (median=1592 pg ml–1; range 141–12 643) showed higher MIC-1 concentrations than patients with junctional (median=1337 pg ml–1; range 383–39 053) and oesophageal tumours (median=1180 pg ml–1; range 258–31 184; P=0.015). Patients showed a median weight loss of 6.4% (range 0.0–33.4%), and 42% of patients had an mGPS of 1 or plasma CRP of 10 mg l–1 (median=9 mg l–1; range 1–200). MIC-1 correlated positively with disease stage (r2=0.217; P<0.001), age (r2=0.332; P<0.001), CRP (r2=0.314; P<0.001), and mGPS (r2=0.336; P<0.001), and negatively with Karnofsky Performance Score (r2=−0.269; P<0.001). However, although MIC-1 correlated weakly with dietary intake (r2=0.157; P=0.031), it did not correlate with weight loss, BMI, or anthropometry. Patients with MIC-1 levels in the upper quartile showed reduced survival (median=204 days; 95% CI 157–251) when compared with patients with MIC-1 levels in the lower three quartiles (median=316 days; 95% CI 259–373; P=0.036), but MIC-1 was not an independent prognostic indicator.Conclusions:There is no independent link between plasma MIC-1 levels and depleted nutritional status or survival in OGC. [ABSTRACT FROM AUTHOR]

Cancer cachexia is characterised by metabolic alterations leading to loss of adipose tissue and lean body mass and directly compromises physical performance and the quality of life of cancer patients. In a murine cancer cachectic model, the effects of dietary supplementation with a specific combination of high protein, leucine and fish oil on weight loss, muscle function and physical activity were investigated. Male CD2F1 mice, 6-7 weeks old, were divided into body weight-matched groups: (1) control, (2) tumour-bearing, and (3) tumour-bearing receiving experimental diets. Tumours were induced by s.c. inoculation with murine colon adenocarcinoma (C26) cells. Food intake, body mass, tumour size and 24 h-activity were monitored. Then, 20 days after tumour/vehicle inoculation, the animals were killed and muscle function was tested ex vivo. Tumour-bearing mice showed reduced carcass, muscle and fat mass compared with controls. EDL muscle performance and total daily activity were impaired in the tumour-bearing mice. Addition of single nutrients resulted in no or modest effects. However, supplementation of the diet with the all-in combination of high protein, leucine and fish oil significantly reduced loss of carcass, muscle and fat mass (loss in mass 45, 52 and 65% of TB-con, respectively (P<0.02)) and improved muscle performance (loss of max force reduced to 55-64% of TB-con (P<0.05)). Moreover, total daily activity normalised after intervention with the specific nutritional combination (50% of the reduction in activity of TB-con (P<0.05)). In conclusion, a nutritional combination of high protein, leucine and fish oil reduced cachectic symptoms and improved functional performance in cancer cachectic mice. Comparison of the nutritional combination with its individual modules revealed additive effects of the single components provided. [ABSTRACT FROM AUTHOR]

Although weight loss is often a dominant symptom in patients with upper gastrointestinal malignancy, there is a lack of objective evidence describing changes in nutritional status and potential associations between weight loss, food intake, markers of systemic inflammation and stage of disease in such patients. Two hundred and twenty patients diagnosed with gastric/oesophageal cancer were studied. Patients underwent nutritional assessment consisting of calculation of body mass index, measurement of weight loss, dysphagia scoring and estimation of dietary intake. Serum acute-phase protein concentrations were determined by enzyme-linked immunosorbent assay. In all, 182 (83%) patients had lost weight at diagnosis (median loss, 7% body weight). Weight loss was associated with poor performance status, advanced disease stage, dysphagia, reduced dietary intake and elevated serum C-reactive protein (CRP) concentrations. Multiple regression identified dietary intake (estimate of effect, 38%), serum CRP concentrations (estimate of effect, 34%) and stage of disease (estimate of effect, 28%) as independent variables in determining degree of weight loss. Mechanisms other than reduced dietary intake or mechanical obstruction by the tumour appear to be involved in the nutritional decline in patients with gastro-oesophageal malignancy. Recognition that systemic inflammation plays a role in nutritional depletion may inform the development of appropriate therapeutic strategies to ameliorate weight loss, making patients more tolerant of cancer-modifying treatments such as chemotherapy. [ABSTRACT FROM AUTHOR]

The majority of patients with advanced cancer are recognised by impaired immune competence influenced by several factors, including the type and stage of the tumour and the presence of cachexia. Recently, a specific nutritional combination containing fish oil, specific oligosaccharide mixture, high protein content and leucine has been developed aimed to support the immune system of cancer patients in order to reduce the frequency and severity of (infectious) complications. In a recently modified animal model cachexia is induced by inoculation of C26 tumour cells in mice. In a pre-cachectic state, no effect was observed on contact hypersensitivity, a validated in vivo method to measure Th1-mediated immune function, after adding the individual nutritional ingredients to the diet of tumour-bearing mice. However, the complete mixture resulted in significantly improved Th1 immunity. Moreover, in a cachectic state, the complete mixture reduced plasma levels of pro-inflammatory cytokines and beneficially affected ex vivo immune function. Accordingly, the combination of the nutritional ingredients is required to obtain a synergistic effect, leading to a reduced inflammatory state and improved immune competence. From this, it can be concluded that the specific nutritional combination has potential as immune-supporting nutritional intervention to reduce the risk of (infectious) complications in cancer patients. [ABSTRACT FROM AUTHOR]

Previous studies suggest that the activation (autophosphorylation) of dsRNA-dependent protein kinase (PKR) can stimulate protein degradation, and depress protein synthesis in skeletal muscle through phosphorylation of the translation initiation factor 2 (eIF2) on the alpha-subunit. To understand whether these mediators are important in muscle wasting in cancer patients, levels of the phospho forms of PKR and eIF2alpha have been determined in rectus abdominus muscle of weight losing patients with oesophago-gastric cancer, in comparison with healthy controls. Levels of both phospho PKR and phospho eIF2alpha were significantly enhanced in muscle of cancer patients with weight loss irrespective of the amount and there was a linear relationship between phosphorylation of PKR and phosphorylation of eIF2alpha (correlation coefficient 0.76, P=0.005). This suggests that phosphorylation of PKR led to phosphorylation of eIF2alpha. Myosin levels decreased as the weight loss increased, and there was a linear relationship between myosin expression and the extent of phosphorylation of eIF2alpha (correlation coefficient 0.77, P=0.004). These results suggest that phosphorylation of PKR may be an important initiator of muscle wasting in cancer patients. [ABSTRACT FROM AUTHOR]

Twenty-one adult patients were randomised to receive ghrelin on days 1 and 8 and placebo on days 4 and 11 or vice versa, given intravenously over a 60-min period before lunch: 10 received 2 microg kg(-1) (lower-dose) ghrelin; 11 received 8 microg kg(-1) (upper-dose) ghrelin. Active and total ghrelin, growth hormone (GH), and insulin-like growth factor 1 levels were monitored at baseline (4-5 days before day 1), during treatment days, and at end of study (day 17/18). Drug-related adverse events (assessed by NCI-CTC-toxicity criteria and cardiac examination) did not differ between ghrelin and placebo. No grade 3/4 toxicity or stimulation of tumour growth was observed. The peak increase of GH, a biological marker of ghrelin action, was 25 ng ml(-1) with lower-dose and 42 ng ml(-1) with upper-dose ghrelin. Morning fasting total ghrelin levels were higher (P<0.05) for upper-dose patients at end of study (3580 pg ml(-1)) than at baseline (990 pg ml(-1)). Insulin-like growth factor 1 levels did not change. At day 8, 81% of patients preferred ghrelin to placebo as against 63% at the end of study. Nutritional intake and eating-related symptoms, measured to explore preliminary efficacy, did not differ between ghrelin and placebo. Ghrelin is well tolerated and safe in patients with advanced cancer. For safety, tolerance, and patients' preference for treatment, no difference was observed between the lower- and upper-dose group. [ABSTRACT FROM AUTHOR]

Atrophy of skeletal muscle is due to a depression in protein synthesis and an increase in degradation. Studies in vitro have suggested that activation of the dsRNA-dependent protein kinase (PKR) may be responsible for these changes in protein synthesis and degradation. In order to evaluate whether this is also applicable to cancer cachexia the action of a PKR inhibitor on the development of cachexia has been studied in mice bearing the MAC16 tumour. Treatment of animals with the PKR inhibitor (5 mg kg−1) significantly reduced levels of phospho-PKR in muscle down to that found in non-tumour-bearing mice, and effectively attenuated the depression of body weight, with increased muscle mass, and also inhibited tumour growth. There was an increase in protein synthesis in skeletal muscle, which paralleled a decrease in eukaryotic initiation factor 2α phosphorylation. Protein degradation rates in skeletal muscle were also significantly decreased, as was proteasome activity levels and expression. Myosin levels were increased up to values found in non-tumour-bearing animals. Proteasome expression correlated with a decreased nuclear accumulation of nuclear factor-κB (NF-κB). The PKR inhibitor also significantly inhibited tumour growth, although this appeared to be a separate event from the effect on muscle wasting. These results suggest that inhibition of the autophosphorylation of PKR may represent an appropriate target for the attenuation of muscle atrophy in cancer cachexia.British Journal of Cancer (2007) 96, 1216–1222. doi:10.1038/sj.bjc.6603704 www.bjcancer.com Published online 27 January 2007 [ABSTRACT FROM AUTHOR]

Extensive loss of adipose tissue is a hallmark of cancer cachexia but the cellular and molecular basis remains unclear. This study has examined morphologic and molecular characteristics of white adipose tissue in mice bearing a cachexia-inducing tumour, MAC16. Adipose tissue from tumour-bearing mice contained shrunken adipocytes that were heterogeneous in size. Increased fibrosis was evident by strong collagen-fibril staining in the tissue matrix. Ultrastructure of 'slimmed' adipocytes revealed severe delipidation and modifications in cell membrane conformation. There were major reductions in mRNA levels of adipogenic transcription factors including CCAAT/enhancer binding protein alpha (C/EBPalpha), CCAAT/enhancer binding protein beta, peroxisome proliferator-activated receptor gamma, and sterol regulatory element binding protein-1c (SREBP-1c) in adipose tissue, which was accompanied by reduced protein content of C/EBPalpha and SREBP-1. mRNA levels of SREBP-1c targets, fatty acid synthase, acetyl CoA carboxylase, stearoyl CoA desaturase 1 and glycerol-3-phosphate acyl transferase, also fell as did glucose transporter-4 and leptin. In contrast, mRNA levels of peroxisome proliferators-activated receptor gamma coactivator-1alpha and uncoupling protein-2 were increased in white fat of tumour-bearing mice. These results suggest that the tumour-induced impairment in the formation and lipid storing capacity of adipose tissue occurs in mice with cancer cachexia. [ABSTRACT FROM AUTHOR]

Proteolysis-inducing factor, a cachexia-inducing tumour product, is an N-glycosylated peptide with homology to the unglycosylated neuronal survival peptide Y-P30 and a predicted product of the dermcidin gene, a pro-survival oncogene in breast cancer. We aimed to investigate whether dermcidin is pro-survival in liver cells, in which proteolysis-inducing factor induces catabolism, and to determine the role of potentially glycosylated asparagine residues in this function. Reverse cloning of proteolysis-inducing factor demonstrated approximately 100% homology with the dermcidin cDNA. This cDNA was cloned into pcDNA3.1+ and both asparagine residues removed using site-directed mutagenesis. In vitro translation demonstrated signal peptide production, but no difference in molecular weight between the products of native and mutant vectors. Immunocytochemistry of HuH7 cells transiently transfected with V5-His-tagged dermcidin confirmed targeting to the secretory pathway. Stable transfection conferred protection against oxidative stress. This was abrogated by mutation of both asparagines in combination, but not by mutation of either asparagine alone. These findings suggest that dermcidin may function as an oncogene in hepatic as well as breast cells. Glycosylation does not appear to be required, but the importance of asparagine residues suggests a role for the proteolysis-inducing factor core peptide domain. [ABSTRACT FROM AUTHOR]

Gastro-oesophageal cancer is associated with a high incidence of cachexia. Proteolysis-inducing factor (PIF) has been identified as a possible cachectic factor and studies suggest that PIF is produced exclusively by tumour cells. We investigated PIF core peptide (PIF-CP) mRNA expression in tumour and benign tissue from patients with gastro-oesophageal cancer and in gastro-oesophageal biopsies for healthy volunteers. Tumour tissue and adjacent benign tissue were collected from patients with gastric and oesophageal cancer (n=46) and from benign tissue only in healthy controls (n=11). Expression of PIF-CP mRNA was quantified by real-time PCR. Clinical and pathological information along with nutritional status was collected prospectively. In the cancer patients, PIF-CP mRNA was detected in 27 (59%) tumour samples and 31 (67%) adjacent benign tissue samples. Four (36%) gastro-oesophageal biopsies from healthy controls also expressed PIF-CP mRNA. Expression was higher in tumour tissue (P=0.031) and benign tissue (P=0.022) from cancer patients compared with healthy controls. In the cancer patients, tumour and adjacent benign tissue PIF-CP mRNA concentrations were correlated with each other (P<0.0001, r=0.73) but did not correlate with weight loss or prognosis. Although PIF-CP mRNA expression is upregulated in both tumour and adjacent normal tissue in gastro-oesophageal malignancy, expression does not relate to prognosis or cachexia. Post-translational modification of PIF may be a key step in determining the biological role of PIF in the patient with advanced cancer and cachexia. [ABSTRACT FROM AUTHOR]

Muscle protein degradation is thought to play a major role in muscle atrophy in cancer cachexia. To investigate the importance of the ubiquitin-proteasome pathway, which has been suggested to be the main degradative pathway mediating progressive protein loss in cachexia, the expression of mRNA for proteasome subunits C2 and C5 as well as the ubiquitin-conjugating enzyme, E214k, has been determined in gastrocnemius and pectoral muscles of mice bearing the MAC16 adenocarcinoma, using competitive quantitative reverse transcriptase polymerase chain reaction. Protein levels of proteasome subunits and E214k were determined by immunoblotting, to ensure changes in mRNA were reflected in changes in protein expression. Muscle weights correlated linearly with weight loss during the course of the study. There was a good correlation between expression of C2 and E214k mRNA and protein levels in gastrocnemius muscle with increases of 6–8-fold for C2 and two-fold for E214k between 12 and 20% weight loss, followed by a decrease in expression at weight losses of 25–27%, although loss of muscle protein continued. In contrast, expression of C5 mRNA only increased two-fold and was elevated similarly at all weight losses between 7.5 and 27%. Both proteasome functional activity, and proteasome-specific tyrosine release as a measure of total protein degradation was also maximal at 18–20% weight loss and decreased at higher weight loss. Proteasome expression in pectoral muscle followed a different pattern with increases in C2 and C5 and E214k mRNA only being seen at weight losses above 17%, although muscle loss increased progressively with increasing weight loss. These results suggest that activation of the ubiquitin-proteasome pathway plays a major role in protein loss in gastrocnemius muscle, up to 20% weight loss, but that other factors such as depression in protein synthesis may play a more important role at higher weight loss.British Journal of Cancer (2005) 93, 774–780. doi:10.1038/sj.bjc.6602780 www.bjcancer.com Published online 6 September 2005 [ABSTRACT FROM AUTHOR]

The ability of angiotensin I (Ang I) and II (Ang II) to induce directly protein degradation in skeletal muscle has been studied in murine myotubes. Angiotensin I stimulated protein degradation with a parabolic dose–response curve and with a maximal effect between 0.05 and 0.1 μM. The effect was attenuated by coincubation with the angiotensin-converting enzyme (ACE) inhibitor imidaprilat, suggesting that angiotensin I stimulated protein degradation through conversion to Ang II. Angiotensin II also stimulated protein breakdown with a similar dose–response curve, and with a maximal effect between 1 and 2.5 μM. Total protein degradation, induced by both Ang I and Ang II, was attenuated by the proteasome inhibitors lactacystin (5 μM) and MG132 (10 μM), suggesting that the effect was mediated through upregulation of the ubiquitin–proteasome proteolytic pathway. Both Ang I and Ang II stimulated an increased proteasome ‘chymotrypsin-like’ enzyme activity as well as an increase in protein expression of 20S proteasome α-subunits, the 19S subunits MSS1 and p42, at the same concentrations as those inducing protein degradation. The effect of Ang I was attenuated by imidaprilat, confirming that it arose from conversion to Ang II. These results suggest that Ang II stimulates protein degradation in myotubes through induction of the ubiquitin–proteasome pathway. Protein degradation induced by Ang II was inhibited by insulin-like growth factor and by the polyunsaturated fatty acid, eicosapentaenoic acid. These results suggest that Ang II has the potential to cause muscle atrophy through an increase in protein degradation. The highly lipophilic ACE inhibitor imidapril (Vitor™) (30 mg kg−1) attenuated the development of weight loss in mice bearing the MAC16 tumour, suggesting that Ang II may play a role in the development of cachexia in this model.British Journal of Cancer (2005) 93, 425–434. doi:10.1038/sj.bjc.6602725 www.bjcancer.com Published online 26 July 2005 [ABSTRACT FROM AUTHOR]

A joint workshop held by Cancer Research UK and the Medical Research Council aimed to stimulate interest in further research into the area of cancer cachexia. The workshop was divided into four sessions: an overview of cancer cachexia, potential mechanisms involved and methodologies that might be used to understand cachexia, and also the experience of cachexia from other disease areas. The workshop identified a need to develop a multimodal therapeutic approach to cancer cachexia and a need to undertake more multidisciplinary research.British Journal of Cancer (2005) 92, 1830-1833. doi:10.1038/sj.bjc.6602565 www.bjcancer.com Published online 19 April 2005 [ABSTRACT FROM AUTHOR]

Loss of adipose tissue in cancer cachexia in mice bearing the MAC16 tumour arises from an increased lipid mobilisation through increased expression of zinc-a2-glycoprotein (ZAG) in white (WAT) and brown (BAT) adipose tissue. Glucocorticoids have been suggested to increase ZAG expression, and this study examines their role in cachexia and the mechanisms involved. In mice bearing the MAC16 tumour, serum cortisol concentrations increased in parallel with weight loss, and the glucocorticoid receptor antagonist RU38486 (25?mg?kg-1) attenuated both the loss of body weight and ZAG expression in WAT. Dexamethasone (66?µg?kg-1) administration to normal mice produced a six-fold increase in ZAG expression in both WAT and BAT, which was also attenuated by RU38486. In vitro studies using 3T3-L1 adipocytes showed dexamethasone (1.68?µM) to stimulate lipolysis and increase ZAG expression, and both were attenuated by RU38486 (10?µM), anti-ZAG antibody (1?µgml-1), and theß3-adrenoreceptor (ß3-AR) antagonist SR59230A (10?µM). Zinc-a2-glycoprotein also increased its own expression and this was attenuated by SR59230A, suggesting that it was mediated through theß3-AR. This suggests that glucocorticoids stimulate lipolysis through an increase in ZAG expression, and that they are responsible for the increase in ZAG expression seen in adipose tissue of cachectic mice.British Journal of Cancer (2005) 92, 876-881. doi:10.1038/sj.bjc.6602404 www.bjcancer.com Published online 15 February 2005 [ABSTRACT FROM AUTHOR]

Loss of skeletal muscle in cancer cachexia has a negative effect on both morbidity and mortality. The role of nuclear factor-?B (NF-?B) in regulating muscle protein degradation and expression of the ubiquitin-proteasome proteolytic pathway in response to a tumour cachectic factor, proteolysis-inducing factor (PIF), has been studied by creating stable, transdominant-negative, muscle cell lines. Murine C2C12 myoblasts were transfected with plasmids with a CMV promoter that had mutations at the serine phosphorylation sites required for degradation of I-?Ba, an NF-?B inhibitory protein, and allowed to differentiate into myotubes. Proteolysis-inducing factor induced degradation of I-?Ba, nuclear accumulation of NF-?B and an increase in luciferase reporter gene activity in myotubes containing wild-type, but not mutant, I-?Baproteins. Proteolysis-inducing factor also induced total protein degradation and loss of the myofibrillar protein myosin in myotubes containing wild-type, but not mutant, plasmids at the same concentrations as those causing activation of NF-?B. Proteolysis-inducing factor also induced increased expression of the ubiquitin-proteasome pathway, as determined by‘chymotrypsin-like’enzyme activity, the predominant proteolytic activity of theß-subunits of the proteasome, protein expression of 20Sa-subunits and the 19S subunits MSS1 and p42, as well as the ubiquitin conjugating enzyme, E214k, in cells containing wild-type, but not mutant, I-?Ba. The ability of mutant I-?Bato inhibit PIF-induced protein degradation, as well as expression of the ubiquitin-proteasome pathway, confirms that both of these responses depend on initiation of transcription by NF-?B.British Journal of Cancer (2005) 92, 711-721. doi:10.1038/sj.bjc.6602402 www.bjcancer.com Published online 15 February 2005 [ABSTRACT FROM AUTHOR]

Atrophy of skeletal muscle reduces both the quality and quantity of life of patients with cancer cachexia. Loss of muscle mass is thought to arise from a reduction in protein synthesis combined with an enhanced rate of protein degradation, and few treatments are available to counteract this process. Eicosapentaenoic acid (EPA) has been shown to attenuate the enhanced protein degradation, but to have no effect on protein synthesis. This study examines the effect of EPA combined with a protein and amino-acid supplementation on protein synthesis and degradation in gastrocnemius muscle of mice bearing the cachexia-inducing MAC16 tumour. Muscles from cachectic mice showed an 80% reduction in protein synthesis and about a 50-fold increase in protein degradation compared with muscles from nontumour-bearing mice of the same age and weight. Treatment with EPA (1?g?kg-1) daily reduced protein degradation by 88%, but had no effect on protein synthesis. Combination of EPA with casein (5.35?g?kg-1) also had no effect on protein synthesis, but when combined with the amino acids leucine, arginine and methionine there was almost a doubling of protein synthesis. The addition of carbohydrate (10.7?g?kg-1) to stimulate insulin release had no additional effect. The combination involving the amino acids produced almost a doubling of the ratio of protein synthesis to protein degradation in gastrocnemius muscle over that of EPA alone. No treatment had a significant effect on tumour growth rate, but the inclusion of amino acids had a more significant effect on weight loss induced by the MAC16 tumour than that of EPA alone. The results suggest that combination therapy of cancer cachexia involving both inhibition of the enhanced protein degradation and stimulation of the reduced protein synthesis may be more effective than either treatment alone.British Journal of Cancer (2004) 91, 408-412. doi:10.1038/sj.bjc.6601981 www.bjcancer.com Published online 22 June 2004 [ABSTRACT FROM AUTHOR]

Lipid-mobilising factor (LMF) is produced by cachexia-inducing tumours and is involved in the degradation of adipose tissue, with increased oxidation of the released fatty acids through an induction of uncoupling protein (UCP) expression. Since UCP-2 is thought to be involved in the detoxification of free radicals if LMF induced UCP-2 expression in tumour cells, it might attenuate free radical toxicity. As a model system we have used MAC13 tumour cells, which do not produce LMF. Addition of LMF caused a concentration-dependent increase in UCP-2 expression, as determined by immunoblotting. This effect was attenuated by the beta3 antagonist SR59230A, suggesting that it was mediated through a beta3 adrenoreceptor. Co-incubation of LMF with MAC13 cells reduced the growth-inhibitory effects of bleomycin, paraquat and hydrogen peroxide, known to be free radical generators, but not chlorambucil, an alkylating agent. There was no effect of LMF alone on cellular proliferation. These results indicate that LMF antagonises the antiproliferative effect of agents working through a free radical mechanism, and may partly explain the unresponsiveness to the chemotherapy of cachexia-inducing tumours. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the total energy expenditure (TEE), resting energy expenditure (REE) and physical activity level (PAL) in home-living cachectic patients with advanced pancreatic cancer. The influence of an energy and protein dense oral supplement either enriched with or without the n-3 fatty acid eicosapentaenoic acid (EPA) and administered over an 8-week period was also determined. In total, 24 patients were studied at baseline. The total energy expenditure was measured using doubly labelled water and REE determined by indirect calorimetry. Patients were studied at baseline and then randomised to either oral nutritional supplement. Measurements were repeated at 8 weeks. At baseline, REE was increased compared with predicted values for healthy individuals (1387(42) vs 1268(32)?kcal?day-1, P=0.001), but TEE (1732(82) vs 1903(48)?kcal?day-1, P=0.023) and PAL (1.24(0.04) vs 1.50) were reduced. After 8 weeks, the REE, TEE and PAL of patients who received the control supplement did not change significantly. In contrast, although REE did not change, TEE and PAL increased significantly in those who received the n-3 (EPA) enriched supplement. In summary, patients with advanced pancreatic cancer were hypermetabolic. However, TEE was reduced and this was secondary to a reduction in physical activity. The control energy and protein dense oral supplement did not influence the physical activity component of TEE. In contrast, administration of the supplement enriched with EPA was associated with an increase in physical activity, which may reflect improved quality of life.British Journal of Cancer (2004) 90, 996-1002. doi:10.1038/sj.bjc.6601620 www.bjcancer.com [ABSTRACT FROM AUTHOR]

The growth potential of a tumour can significantly depend on host features such as age, cell proliferation rates and caloric intake. Although this is widely known, existing mathematical models for tumour growth do not account for it. We therefore developed a new model for tumour growth, starting from a mathematical framework that describes the host's physiology. The resulting tumour-in-host model allowed us to study the implications of various specific interactions between the energetics of tumour and host. The model accounts for the influence of both age and feeding regimen of the host organism on the behaviour of a tumour. Concerning the effects of a tumour on its host, it explains why tumour-mediated body-weight loss is often more dramatic than expected from the energy demands of the tumour. We also show how the model can be applied to study enhanced body-weight loss in presence of cachectic factors. Our tumour-in-host model thus appears a proper tool to unite a wide range of phenomena in tumour-host interactions. [ABSTRACT FROM AUTHOR]

Proteolysis-inducing factor (PIF), isolated from a cachexia-inducing murine tumour, has been shown to stimulate protein breakdown in C(2)C(12) myotubes. The effect was attenuated by the specific proteasome inhibitor lactacystin and there was an elevation of proteasome 'chymotrypsin-like' enzyme activity and expression of 20S proteasome alpha-subunits at concentrations of PIF between 2 and 16 nM. Higher concentrations of PIF had no effect. The action of PIF was attenuated by eicosapentaenoic acid (EPA) (50 microM). At a concentration of 4 nM, PIF induced a transient decrease in IkappaBalpha levels after 30 min incubation, while no effect was seen at 20 nM PIF. The level of IkappaBalpha, an NF-kappaB inhibitory protein, returned to normal after 60 min. Depletion of IkappaBalpha from the cytosol was not seen in myotubes pretreated with EPA, suggesting that the NF-kappaB/IkappaB complex was stabilised. At concentrations between 2 and 8 nM, PIF stimulated an increased nuclear migration of NF-kappaB, which was not seen in myotubes pretreated with EPA. The PIF-induced increase in chymotrypsin-like enzyme activity was also attenuated by the NF-kappaB inhibitor peptide SN50, suggesting that NF-kappaB may be involved in the PIF-induced increase in proteasome expression. The results further suggest that EPA may attenuate protein degradation induced by PIF, at least partly, by preventing NF-kappaB accumulation in the nucleus. [ABSTRACT FROM AUTHOR]

Treatment of ex-breeder male NMRI mice with lipid mobilising factor isolated from the urine of cachectic cancer patients, caused a significant increase in glucose oxidation to CO2 compared with control mice receiving phosphate buffered saline. Glucose utilisation by various tissues was determined by the 2-deoxyglucose tracer technique and shown to be elevated in brain, heart, brown adipose tissue and gastrocnemius muscle. The tissue glucose metabolic rate was increased almost three-fold in brain, accounting for the ability of lipid mobilising factor to decrease blood glucose levels. Lipid mobilising factor also increased overall lipid oxidation, as determined by the production of 14CO2 from [14C carboxy] triolein, being 67% greater than phosphate buffered saline controls over a 24 h period. There was a significant increase in [14C] lipid accumulation in plasma, liver and white and brown adipose tissue after administration of lipid mobilising factor. These results suggest that changes in carbohydrate metabolism and loss of adipose tissue, together with an increased whole body fatty acid oxidation in cachectic cancer patients, may arise from tumour production of lipid mobilising factor. [ABSTRACT FROM AUTHOR]

The mechanism of muscle protein catabolism induced by proteolysis-inducing factor, produced by cachexia-inducing murine and human tumours has been studied in vitro using C(2)C(12) myoblasts and myotubes. In both myoblasts and myotubes protein degradation was enhanced by proteolysis-inducing factor after 24 h incubation. In myoblasts this followed a bell-shaped dose-response curve with maximal effects at a proteolysis-inducing factor concentration between 2 and 4 nM, while in myotubes increased protein degradation was seen at all concentrations of proteolysis-inducing factor up to 10 nM, again with a maximum of 4 nM proteolysis-inducing factor. Protein degradation induced by proteolysis-inducing factor was completely attenuated in the presence of cycloheximide (1 microM), suggesting a requirement for new protein synthesis. In both myoblasts and myotubes protein degradation was accompanied by an increased expression of the alpha-type subunits of the 20S proteasome as well as functional activity of the proteasome, as determined by the 'chymotrypsin-like' enzyme activity. There was also an increased expression of the 19S regulatory complex as well as the ubiquitin-conjugating enzyme (E2(14k)), and in myotubes a decrease in myosin expression was seen with increasing concentrations of proteolysis-inducing factor. These results show that proteolysis-inducing factor co-ordinately upregulates both ubiquitin conjugation and proteasome activity in both myoblasts and myotubes and may play an important role in the muscle wasting seen in cancer cachexia. [ABSTRACT FROM AUTHOR]

Intraperitoneal administration of 100 microg kg(-1) (body weight) of tumour necrosis factor-alpha to rats for 8 consecutive days resulted in a significant decrease in protein content, which was concomitant with a reduction in DNA content. Interestingly, the protein/DNA ratio was unchanged in the skeletal muscle of the tumour necrosis factor-alpha-treated animals as compared with the non-treated controls. Analysis of muscle DNA fragmentation clearly showed enhanced laddering in the skeletal muscle of tumour necrosis factor-alpha-treated animals, suggesting an apoptotic phenomenon. In a different set of experiments, mice bearing a cachexia-inducing tumour (the Lewis lung carcinoma) showed an increase in muscle DNA fragmentation (9.8-fold) as compared with their non-tumour-bearing control counterparts as previously described. When gene-deficient mice for tumour necrosis factor-alpha receptor protein I were inoculated with Lewis lung carcinoma, they were also affected by DNA fragmentation; however the increase was only 2.1-fold. These results suggest that tumour necrosis factor-alpha partly mediates DNA fragmentation during experimental cancer-associated cachexia. [ABSTRACT FROM AUTHOR]

The abnormalities of lipid metabolism observed in cancer cachexia may be induced by a lipid-mobilizing factor produced by adenocarcinomas. The specific molecules and metabolic pathways that mediate the actions of lipid-mobilizing factor are not known. The mitochondrial uncoupling proteins-1, -2 and -3 are suggested to play essential roles in energy dissipation and disposal of excess lipid. Here, we studied the effects of lipid-mobilizing factor on the expression of uncoupling proteins-1, -2 and -3 in normal mice. Lipid-mobilizing factor isolated from the urine of cancer patients was injected intravenously into mice over a 52-h period, while vehicle was similarly given to controls. Lipid-mobilizing factor caused significant reductions in body weight (-10%, P=0.03) and fat mass (-20%, P<0.01) accompanied by a marked decrease in plasma leptin (-59%, P<0.01) and heavy lipid deposition in the liver. In brown adipose tissue, uncoupling protein-1 mRNA levels were elevated in lipid-mobilizing factor-treated mice (+96%, P<0.01), as were uncoupling proteins-2 and -3 (+57% and +37%, both P<0.05). Lipid-mobilizing factor increased uncoupling protein-2 mRNA in both skeletal muscle (+146%, P<0.05) and liver (+142%, P=0.03). The protein levels of uncoupling protein-1 in brown adipose tissue and uncoupling protein-2 in liver were also increased with lipid-mobilizing factor administration (+49% and +67%, both P=0.02). Upregulation by lipid-mobilizing factor of uncoupling proteins-1, -2 and -3 in brown adipose tissue, and of uncoupling protein-2 in skeletal muscle and liver, suggests that these uncoupling proteins may serve to utilize excess lipid mobilized during fat catabolism in cancer cachexia. [ABSTRACT FROM AUTHOR]

Adipocytes isolated from cachectic mice bearing the MAC 16 tumour showed over a 3-fold increase in lipolytic response to both low concentrations of isoprenaline and a tumour-derived lipid mobilizing factor (LMF). This was reflected by an enhanced stimulation of adenylate cyclase in plasma membrane fractions of adipocytes in the presence of both factors. There was no up-regulation of adenylate cyclase in response to forskolin, suggesting that the effect arose from a change in receptor number or G-protein expression. Immunoblotting of adipocyte membranes from mice bearing the MAC16 tumour showed an increased expression of Gαs up to 10% weight loss and a reciprocal decrease in Gα. There was also an increased expression of Gαs and a decrease in Gα in adipose tissue from a patient with cancer-associated weight loss compared with a non-cachectic cancer patient. The changes in G-protein expression were also seen in adipose tissue of normal mice administered pure LMF as well as in 3T3L1 adipocytes in vitro. The changes in G-protein expression induced by LMF were attenuated by the polyunsaturated fatty acid, eicosapentaenoic acid (EPA). This suggests that this tumour-derived lipolytic factor acts to sensitize adipose tissue to lipolytic stimuli, and that this effect is attenuated by EPA, which is known to preserve adipose tissue in cancer cachexia. [ABSTRACT FROM AUTHOR]

Loss of skeletal muscle is a major factor in the poor survival of patients with cancer cachexia. This study examines the mechanism of catabolism of skeletal muscle by a tumour product, proteolysis-inducing factor (PIF). Intravenous administration of PIF to normal mice produced a rapid decrease in body weight (1.55 ± 0.12 g in 24 h) that was accompanied by increased mRNA levels for ubiquitin, the Mr 14 000 ubiquitin carrier-protein, E2, and the C9 proteasome subunit in gastrocnemius muscle. There was also increased protein levels of the 20S proteasome core and 19S regulatory subunit, detectable by immunoblotting, suggesting activation of the ATP-ubiquitin-dependent proteolytic pathway. An increased protein catabolism was also seen in myoblasts within 24 h of PIF addition with a bell-shaped C[SUB2]C[SUB12] dose-response curve and a maximal effect at 2-4 nM. The enhanced protein degradation was attenuated by anti-PIF antibody and by the proteasome inhibitors MG115 and lactacystin. Glycerol gradient analysis of proteasomes from PIF-treated cells showed an elevation in chymotrypsin-like activity, while Western analysis showed a dose-related increase in expression of MSSI, an ATPase that is a regulatory subunit of the proteasome, with a dose-response curve similar to that for protein degradation. These results confirm that PIF acts directly to stimulate the proteasome pathway in muscle cells and may play a pivotal role in protein catabolism in cancer cachexia. [ABSTRACT FROM AUTHOR]

A prominent feature of several type of cancer is cachexia. This syndrome causes a marked loss of lean body mass and muscle wasting, and appears to be mediated by cytokines and tumour products. There are several proteases and proteolytic pathways that could be responsible for the protein breakdown. In the present study, we investigated whether caspases are involved in the proteolytic process of skeletal muscle catabolism observed in a murine model of cancer cachexia (MAC16), in comparison with a related tumour (MAC13), which does not induce cachexia. Using specific peptide substrates, there was an increase of 54% in the proteolytic activity of caspase-1, 84% of caspase-8, 98% of caspase-3 151% to caspase-6 and 177% of caspase-9, in the gastrocnemius muscle of animals bearing the MAC16 tumour (up to 25% weight loss), in relation to muscle from animals bearing the MAC13 tumour (1-5% weight loss). The dual pattern of 89 kDa and 25 kDa fragmentation of poly (ADP-ribose) polymerase (PARP) occurred in the muscle samples from animals bearing the MAC16 tumour and with a high amount of caspase-like activity. Cytochrome c was present in the cytosolic fractions of gastrocnemius muscles from both groups of animals, suggesting that cytochrome c release from mitochondria may be involved in caspase activation. There was no evidence for DNA fragmentation into a nucleosomal ladder typical of apoptosis in the muscles of either group of mice. This data supports a role for caspases in the catabolic events in muscle involved in the cancer cachexia syndrome. [ABSTRACT FROM AUTHOR]

Cachexia is a syndrome characterized by profound tissue wasting that frequently complicates malignancies. In a cancer cachexia model we have shown that protein depletion in the skeletal muscle, which is a prominent feature of the syndrome, is mostly due to enhanced proteolysis. There is consensus on the views that the ubiquitin/proteasome pathway plays an important role in such metabolic response and that cytotoxic cytokines such as TNFα are involved in its triggering (Costelli and Baccino, 2000), yet the mechanisms by which the relevant extracellular signals are transduced into protein hypercatabolism are largely unknown. Moreover, little information is presently available as to the possible involvement in muscle protein waste of the Ca[SUP2+]-dependent proteolysis, which may provide a rapidly activated system in response to the extracellular signals. In the present work we have evaluated the status of the Ca[SUP2+]-dependent proteolytic system in the gastrocnemius muscle of AH-130 tumour-bearing rats by assaying the activity of calpain as well as the levels of calpastatin, the natural calpain inhibitor, and of the 130 kDa Ca[SUP2+]-ATPase, both of which are known calpain substrates. After tumour transplantation, total calpastatin activity progressively declined, while total calpain activity remained unchanged, resulting in a progressively increasing unbalance in the calpain/calpastatin ratio. A decrease was also observed for the 130 kDa plasma membrane form of Ca[SUP2+]-ATPase, while there was no change in the level of the 90 kDa sarcoplasmic Ca[SUP2+]-ATPase, which is resistant to the action of calpain. Decreased levels of both calpastatin and 130 kDa Ca[SUP2+]-ATPase have been also detected in the heart of the tumour-bearers. These observations strongly suggest that Ca[SUP2+]-dependent proteolysis was activated in the skeletal muscle and heart of tumour-bearing animals and raise the possibility that such activation may play a role in sparking off the... [ABSTRACT FROM AUTHOR]

Pro-inflammatory cytokines contribute to the cachexia associated with pancreatic cancer and stimulate the acute phase response which has been associated with shortened survival in such patients. Polymorphisms of cytokine genes may influence their production. The present study examined the effect of a polymorphism of the interleukin (IL)-1b gene upon the inflammatory state and survival in pancreatic cancer. Genomic DNA was obtained from 64 patients with pancreatic cancer and 101 healthy controls. Using the polymerase chain reaction and subsequent TaqI restriction enzyme digestion the subject's genotype for a diallelic polymorphism of the interleukin-1b gene was established. IL-1b production by peripheral blood mononuclear cells and serum C-reactive protein (CRP) levels from patients were also examined and survival noted. Patients homozygous for allele 2 of the IL-1b gene had significantly shorter survival than other groups (P = 0.0001). These patients also exhibited higher IL-1b production (P = 0.022). Possession of allele 2 was also associated with significantly shorter survival (median 144 vs 256 days, P = 0.034) and significantly higher CRP level (P = 0.0003). The possession of a genotype resulting in increased IL-1b production was associated with shortened survival and increased serum CRP level. This may reflect the role of IL-1b in inducing an acute phase protein response and cachexia in cancer or may be related to changes in tumour phenotye. [ABSTRACT FROM AUTHOR]

The implication of an increase in energy expenditure in cancer cachexia, which seems to be related to the type of tumour, remains unclear. We therefore investigated the energy metabolism and body temperature in anorectic and cachectic rats bearing the Yoshida sarcoma (TB), in comparison with pair-fed (PF) and ad-libitum fed (AL) control rats. The resting energy expenditure was higher in the TB than in the two control groups when corrected for the modifications of body composition. However, the total energy expenditure did not differ between the TB and the AL, presumably because of the drop of activity in TB. There was a temporal distribution of differences in energy expenditure with higher energy expenditure in TB than in AL during the diurnal phase and a lack of difference during the nocturnal phase. The TB presented a fever, which was limited to the diurnal period. Moreover, the acrophase of the body temperature rhythm was delayed in the TB. These results highlight the circadian effects of tumour development on the energy metabolism of the host and hint to the possible implication of cytokines. © 2000 Harcourt Publishers Ltd © 2000 Cancer Research Campaign [ABSTRACT FROM AUTHOR]

Tissue protein hypercatabolism (TPH) is an important feature in cancer cachexia, particularly with regard to the skeletal muscle. The Yoshida AH-130 rat ascites hepatoma is a model system for studying the mechanisms involved in the processes that lead to tissue depletion, since it induces in the host a rapid and progressive muscle wasting, primarily due to TPH. The present study was aimed at investigating if IL-15, which is known to favour muscle fibre hypertrophy, could antagonize the enhanced muscle protein breakdown in this cancer cachexia model. Indeed, IL-15 treatment partly inhibited skeletal muscle wasting in AH-130-bearing rats by decreasing (8-fold) protein degradative rates (as measured by[SUP14]C-bicarbonate pre-loading of muscle proteins) to values even lower than those observed in non-tumour-bearing animals. These alterations in protein breakdown rates were associated with an inhibition of the ATP-ubiquitin-dependent proteolytic pathway (35% and 41% for 2.4 and 1.2 kb ubiquitin mRNA, and 57% for the C8 proteasome subunit, respectively). The cytokine did not modify the plasma levels of corticosterone and insulin in the tumour hosts. The present data give new insights into the mechanisms by which IL-15 exerts its preventive effect on muscle protein wasting and seem to warrant the implementation of experimental protocols involving the use of the cytokine in the treatment of pathological states characterized by TPH, particularly in skeletal muscle, such as in the present model of cancer cachexia. [ABSTRACT FROM AUTHOR]

The fluorinated pyrimidine nucleoside, 5′-deoxy-5-fluorouridine (5′-dFUrd) has been shown to effectively attenuate the progress of cachexia in the murine adenocarcinomas MAC16 and colon 26 as well as in the human uterine cervical carcinoma xenograft, Yumoto. Although concomitant inhibition of tumour growth was observed in all three models this was not sufficient to account for the preservation of body weight. An attempt has been made to correlate the anti-cachectic activity of 5′-dFUrd with the presence of a tumour produced proteolysis-inducing factor (PIF), thought to be responsible for the development of cachexia in the MAC16 model. Two variants of colon 26 adenocarcinoma were employed, clone 20 which produces profound cachexia, and clone 5 which produces no change in body weight in recipient animals. Mice bearing the colon 26, clone 20 variant showed evidence for the presence of PIF in tumour, serum and urine, while there was no evidence for the presence of PIF in tumour or body fluids of mice bearing the clone 5 tumours. Treatment of animals bearing the clone 20 variant with 5′-dF Urd led to the disappearance of PIF from the tumour, serum and urine concomitant with the attenuation of the development of cachexia. The human cervical carcinoma, Yumoto, which also induced cachexia in recipiant animals, showed expression of PIF in tumour, serum and urine in control and vehicle-treated mice, but was absent in mice treated with 5′-dFUrd. Thus in these experimental models cachexia appears to be correlated with the presence of PIF. [ABSTRACT FROM AUTHOR]

Abnormally low intramuscular glutamate and glutathione (GSH) levels and/or a decreased muscular uptake of glutamate by the skeletal muscle tissue have previously been found in malignant diseases and simian immunodeficiency virus (SIV) infection and may contribute to the development of cachexia. We tested the hypothesis that an impaired mitochondrial energy metabolism may compromise the Na[SUP+]-dependent glutamate transport. A randomized double-blind clinical trial was designed to study the effects of L-carnitine, i.e. an agent known to enhance mitochondrial integrity and function, on the glutamate transport and plasma glutamate level of cancer patients. The effect of carnitine on the intramuscular glutamate and GSH levels was examined in complementary experiments with tumour-bearing mice. In the mice, L-carnitine treatment ameliorated indeed the tumour-induced decrease in muscular glutamate and GSH levels and the increase in plasma glutamate levels. The carnitine-treated group in the randomized clinical study showed also a significant decrease in the plasma glutamate levels but only a moderate and statistically not significant increase in the relative glutamate uptake in the lower extremities. Further studies may be warranted to determine the effect of L-carnitine on the intramuscular GSH levels in cancer patients. [ABSTRACT FROM AUTHOR]

Human melanoma, G361, which induces cachexia in nude mice, has been shown to produce a proteolysis-inducing factor (PIF) of M[SUBr] 24 000, which is immunologically identical to that isolated from a cachexia-inducing murine tumour (MAC16). Biosynthetic labelling of G361 cells using a combination of [[SUP35]S]sulphate and [6-[SUP3]H]glucosamine gave a single component of M[SUBr] 24 000 after affinity chromatography employing a murine monoclonal antibody. The material contained both radiolabels and, after digestion with peptideN-glycosidase F, two fragments were produced of M[SUBr] 14 000 and 10 000 also containing both radiolabels. Digestion with O-glycosidase produced three fragments of M[SUBr] 14 000, 6000 and 4000, the first two of which contained both radiolabels, while the third only contained [SUP3]H. This digestion pattern is the same as that previously observed with PIF from the MAC16 tumour and is commensurate with one N-linked sulphated oligosaccharide chain of M[SUBr] 10 000, one O-linked sulphated oligosaccharide chain of 6000 and a central polypeptide chain of M[SUBr] 4000 with some residual carbohydrate. When PIF from G361 cells was administered to female NMRI mice (20 g) a pronounced depression of body weight (1.36 ± 0.36 g; P < 0.0001 from control) was observed over a 24 h period without a decrease in either food or water consumption. Body composition analysis showed a significant decrease in the non-fat carcass mass without a change in carcass fat or body water. This result suggests that depletion of lean body mass in mice bearing G361 melanoma arises from the production of PIF. [ABSTRACT FROM AUTHOR]