Genetic basis of interindividual susceptibility to cancer cachexia: selection of potential candidate gene polymorphisms for association studies

Association of the rs3917647 polymorphism of the SELP gene with malnutrition in gastric cancer

BACKGROUND

Malnutrition and cachexia are common syndromes in patients with gastric cancer (GC) and are associated with poor quality of life and poor disease prognosis. However, there is still a lack of molecular factors that can predict malnutrition or cachexia in cancer. Studies have shown that among the potential contributors to the development of cancer cachexia, the level of the inflammatory response to P-selectin is regulated by single nucleotide polymorphisms (SNPs) located in the promoter region of the SELP gene. The aim of this study was to evaluate the association between the single nucleotide polymorphism (SNP)-2028 A/G of the SELP gene and malnutrition in patients receiving chemotherapy for gastric cancer (GC).

METHODS

The study group consisted of 220 GC patients treated with chemotherapy at Jinhua Municipal Central Hospital. DNA was extracted from peripheral leukocytes of whole blood samples using an animal DNA extraction kit. DNA was amplified using a 1.1 × T3 Super PCR mix, and loci corresponding to the peaks were genotyped using SNP1 software.

RESULTS

Patients carrying the A allele had a reduced risk of developing malnutrition compared to patients with the GG genotype (P < 0.001; OR = 3.411; 95% CI = 1.785-6.516). In addition, multivariate analysis indicated that the AA genotype significantly (more than 16-fold) reduced the risk of developing malnutrition (P < 0.001; OR = 0.062; 95% CI = 0.015-0.255).

CONCLUSION

SELP -2028A/G SNP may be a useful marker for assessing the risk of malnutrition in GC patients.

TNF-α-1031T/C gene polymorphism as a predictor of malnutrition in patients with gastric cancer

Introduction

Malnutrition is a complex clinical syndrome, the exact mechanism of which is yet not fully understood. Studies have found that malnutrition is associated with anorexia and inadequate intake, tumor depletion, leptin, tumor-induced metabolic abnormalities in the body, and catabolic factors produced by the tumor in the circulation and cytokines produced by the host immune system. Among these, single nucleotide polymorphisms (SNPs) are present in the gene encoding the pro-inflammatory cytokine TNF-α.

Aim

The objective of this study was to investigate TNF-α -1,031 T/C gene polymorphism as an unfavorable predictor of malnutrition in patients with gastric cancer.

Methods

The study group consisted of 220 gastric cancer patients treated at Affiliated Jinhua Hospital, Zhejiang University School of Medicine. Malnutrition was mainly assessed by the Global Consensus on Malnutrition Diagnostic Criteria (GLIM). DNA was extracted from peripheral leukocytes of whole blood samples using an animal DNA extraction kit. DNA was amplified using a 1.1× T3 Super PCR mixture and genotyped using SNP1 software.

Results

There are three major genetic polymorphisms in TNF-α. Among the 220 patients with gastric cancer, there were 7 patients with the CC genotype, 61 with the CT genotype and 152 with the TT genotype. Compared to patients with the TT genotype, patients with the C allele had an approximately 2.5-fold higher risk of developing malnutrition (p = 0.003; OR = 0.406). On the basis of multivariate analysis, patients with the CC genotype had an approximately 20.1-fold higher risk of developing malnutrition (p = 0.013; OR = 20.114), while those with the CT genotype had an almost 3.7-fold higher risk of malnutrition (p = 0.002; OR = 3.218).

Conclusion

SNP (-1,031 T/C) of the TNF-α may be a useful marker in the assessment of the risk of nutritional deficiencies in gastric cancer patients. Patients with gastric cancer carrying the C allele should be supported by early nutritional intervention, but more research is still needed to explore confirmation.

Current Therapeutic Targets in Cancer Cachexia: A Pathophysiologic Approach

Significant progress in our understanding of cancer cachexia has occurred in recent years. Despite these advances, no pharmacologic agent has achieved US Food and Drug Administration approval for this common and highly morbid syndrome. Fortunately, improved understanding of the molecular basis of cancer cachexia has led to novel targeted approaches that are in varying stages of drug development. This article reviews two major thematic areas that are driving these pharmacologic strategies, including those targeting signal mediators at the level of the CNS and skeletal muscle. Additionally, pharmacologic strategies are being tested in combination with targeted nutrients, nutrition therapy, and exercise to treat cancer cachexia. To this end, we highlight recently published and ongoing trials evaluating cancer cachexia therapies in these specific areas.

TNFRSF1A Gene Polymorphism (−610 T > G, rs4149570) as a Predictor of Malnutrition and a Prognostic Factor in Patients Subjected to Intensity-Modulated Radiation Therapy Due to Head and Neck Cancer

Background: Malnutrition is a nutritional disorder observed in 52% of patients with head and neck cancer (HNC). Malnutrition is frequently related to the increased level of proinflammatory cytokines. In turn, ongoing inflammation is associated with increased catabolism of skeletal muscle and lipolysis. Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine that plays a pivotal role in the development of malnutrition and cachexia in cancer patients. The aim of the study was to assess the relationship between a functional single-nucleotide polymorphism (SNP) −610 T > G (rs4149570) of the TNFRSF1A gene and the occurrence of nutritional disorders in patients subjected to RT due to HNC. Methods: The study group consisted of 77 patients with HNC treated at the Oncology Department of the Medical University in Lublin. Genotyping of the TNFRSF1A gene was performed using capillary electrophoresis (Genetic Analyzer 3500). Results: Multivariable analysis revealed that the TT genotype of the TNFRSF1A gene (−610 T > G) was an independent predictor of severe malnutrition (odds ratio—OR = 5.05; p = 0.0350). Moreover, the TT genotype of this gene was independently related to a higher risk of critical weight loss (CWL) (OR = 24.85; p = 0.0009). Conclusions: SNP (−610 T > G) of the TNFRSF1A may be a useful marker in the assessment of the risk of nutritional deficiencies in HNC patients treated with intensity-modulated radiotherapy (IMRT).

Genetic variation in genes regulating skeletal muscle regeneration and tissue remodelling associated with weight loss in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally. COPD patients with cachexia or weight loss have increased risk of death independent of body mass index (BMI) and lung function. We tested the hypothesis genetic variation is associated with weight loss in COPD using a genome-wide association study approach.

METHODS

Participants with COPD (N = 4308) from three studies (COPDGene, ECLIPSE, and SPIROMICS) were analysed. Discovery analyses were performed in COPDGene with replication in SPIROMICS and ECLIPSE. In COPDGene, weight loss was defined as self-reported unintentional weight loss > 5% in the past year or low BMI (BMI < 20 kg/m2 ). In ECLIPSE and SPIROMICS, weight loss was calculated using available longitudinal visits. Stratified analyses were performed among African American (AA) and Non-Hispanic White (NHW) participants with COPD. Single variant and gene-based analyses were performed adjusting for confounders. Fine mapping was performed using a Bayesian approach integrating genetic association results with linkage disequilibrium and functional annotation. Significant gene networks were identified by integrating genetic regions associated with weight loss with skeletal muscle protein-protein interaction (PPI) data.

RESULTS

At the single variant level, only the rs35368512 variant, intergenic to GRXCR1 and LINC02383, was associated with weight loss (odds ratio = 3.6, 95% confidence interval = 2.3-5.6, P = 3.2 × 10-8 ) among AA COPD participants in COPDGene. At the gene level in COPDGene, EFNA2 and BAIAP2 were significantly associated with weight loss in AA and NHW COPD participants, respectively. The EFNA2 association replicated among AA from SPIROMICS (P = 0.0014), whereas the BAIAP2 association replicated in NHW from ECLIPSE (P = 0.025). The EFNA2 gene encodes the membrane-bound protein ephrin-A2 involved in the regulation of developmental processes and adult tissue homeostasis such as skeletal muscle. The BAIAP2 gene encodes the insulin-responsive protein of mass 53 kD (IRSp53), a negative regulator of myogenic differentiation. Integration of the gene-based findings participants with PPI data revealed networks of genes involved in pathways such as Rho and synapse signalling.

CONCLUSIONS

The EFNA2 and BAIAP2 genes were significantly associated with weight loss in COPD participants. Collectively, the integrative network analyses indicated genetic variation associated with weight loss in COPD may influence skeletal muscle regeneration and tissue remodelling.

Nutritional Deficiencies in Radiotherapy-Treated Head and Neck Cancer Patients

Nutritional deficiencies (malnutrition, cachexia, sarcopenia, and unfavorable changes in the body composition) developing as a side effect of radiotherapy (RT) currently represents a significant but still inaccurately studied clinical problem in cancer patients. The incidence of malnutrition observed in head and neck cancer (HNC) patients in oncological radiology departments can reach 80%. The presence of malnutrition, sarcopenia, and cachexia is associated with an unfavorable prognosis of the disease, higher mortality, and deterioration of the quality of life. Therefore, it is necessary to identify patients with a high risk of both metabolic syndromes. However, the number of studies investigating potential predictive markers for the mentioned purposes is still significantly limited. This literature review summarizes the incidence of nutritional deficiencies in HNC patients prior to therapy and after the commencement of RT, and presents recent perspectives for the prediction of unfavorable nutritional changes developing as a result of applied RT.

Polymorphisms in CPT1B and CPT2 have no significant effect on plasma carnitine levels in Japanese cancer patients

Treatment of cancer patients undergoing chemotherapy with L-carnitine (LC) supplementation is becoming increasingly popular in the clinic. The present study aimed to examine the possible effects of polymorphisms in CPT1B and CPT2 (CPT1B G320D, S427C, c.282-18 C>T, and p.E531K, and CPT2 V368I) on the plasma concentration of carnitine in humans. The subjects were the 218 participants of the Iga Cohort Study. Differences in plasma-free carnitine levels by genotype were examined. Genotyping was conducted by polymerase chain reaction with confronting two-pair primers (PCR-CTPP). The plasma carnitine levels were significantly higher in males (P<0.001; Student’s t-test), and there was no significant difference in plasma carnitine levels between the age groups (P=0.202; ANOVA). One-way ANOVA revealed the plasma levels of carnitine were neither significantly different by CPT1B G320D, S427C, c.282-18 C>T, or p.E531K, nor by CPT2 V368I genotypes (P=0.133, P=0.538, P=0.636, P=0.509, and P=0.398, respectively). When analysis of covariance (ANCOVA) adjusted for age and sex was applied, the plasma levels of carnitine were not statistically significantly different according to these genotypes (P=0.299, P=0.715, P=0.980, P=0.851, and P=0.674, respectively). The present study did not identify any statistically significant differences in plasma carnitine levels between subjects with different CPT1 and CPT2 genotypes, suggesting that there may be no need to tailor treatments to patients’ genotypes when determining the dose/amount of LC to be administered to cancer patients undergoing palliative care.

miRNA-130a Significantly Improves Accuracy of SGA Nutritional Assessment Tool in Prediction of Malnutrition and Cachexia in Radiotherapy-Treated Head and Neck Cancer Patients

BACKGROUND

Investigation of novel cachexia-related markers is one of the major challenges in contemporary oncology. Among studied markers, the miRNA seems to be promising due to its possibility to regulate genes responsible for induction of inflammatory response, muscle atrophy and fat tissue wasting. The aim of the study was to investigate the role of blood-circulating miRNA-130a in prediction of cancer cachexia in 70 head and neck cancer patients (HNC) subjected to radiotherapy. Moreover, diagnostic accuracy of SGA (Subjective Global Assessment) scoring and miRNA-130a level was evaluated in various cachexia models.

RESULTS

miRNA-130a level negatively correlated with plasma TNF-α concentration (r = -0.560; p < 0.001). Patients with low miRNA expression had over 3-fold higher risk of body mass index (BMI) decrease below 18.5 after the termination of therapy; over 6-fold higher risk of losing over 5% of body weight and higher risk of >10% weight reduction odds ratio (OR) = 14.18 compared to other cases. ROC analysis performed for miRNA-130a allowed to distinguish cachectic patients (body weight loss >5%) from moderately or mildly malnourished ones with optimal sensitivity of 79.4% and specificity of 80.8% area under the curve (AUC) = 0.865). miRNA significantly improved nutritional assessment conducted using SGA, achieving the following values: sensitivity 88.6%, specificity 94.3%, positive predictive value (PPV) 93.9%, negative predictive value (NPV).89.2%.

CONCLUSION

miRNA-130a demonstrates potential clinical utility in prediction of cachexia prior to the therapy in HNC patients. Simultaneous use of both tools-SGA and miRNA-significantly improved the accuracy in the diagnosis of cachexia.

Differentially expressed alternatively spliced genes in skeletal muscle from cancer patients with cachexia

BACKGROUND

Alternative splicing (AS) is a post-transcriptional gene regulatory mechanism that contributes to proteome diversity. Aberrant splicing mechanisms contribute to various cancers and muscle-related conditions such as Duchenne muscular dystrophy. However, dysregulation of AS in cancer cachexia (CC) remains unexplored. Our objectives were (i) to profile alternatively spliced genes (ASGs) on a genome-wide scale and (ii) to identify differentially expressed alternatively spliced genes (DASGs) associated with CC.

METHODS

Rectus abdominis muscle biopsies obtained from cancer patients were stratified into cachectic cases (n = 21, classified based on International consensus diagnostic framework for CC) and non-cachectic controls (n = 19, weight stable cancer patients). Human transcriptome array 2.0 was used for profiling ASGs using the total RNA isolated from muscle biopsies. Representative DASG signatures were validated using semi-quantitative RT-PCR.

RESULTS

We identified 8960 ASGs, of which 922 DASGs (772 up-regulated and 150 down-regulated) were identified at ≥1.4 fold-change and P < 0.05. Representative DASGs validated by semi-quantitative RT-PCR confirmed the primary findings from the human transcriptome arrays. Identified DASGs were associated with myogenesis, adipogenesis, protein ubiquitination, and inflammation. Up to 10% of the DASGs exhibited cassette exon (exon included or skipped) as a predominant form of AS event. We also observed other forms of AS events such as intron retention, alternate promoters.

CONCLUSIONS

Overall, we have, for the first time, conducted global profiling of muscle tissue to identify DASGs associated with CC. The mechanistic roles of the identified DASGs in CC pathophysiology using model systems is warranted, as well as replication of findings in independent cohorts.

Cancer-associated cachexia

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

Practical multimodal care for cancer cachexia

PURPOSE OF REVIEW

Cancer cachexia is common and reduces function, treatment tolerability and quality of life. Given its multifaceted pathophysiology a multimodal approach to cachexia management is advocated for, but can be difficult to realise in practice. We use a case-based approach to highlight practical approaches to the multimodal management of cachexia for patients across the cancer trajectory.

RECENT FINDINGS

Four cases with lung cancer spanning surgical resection, radical chemoradiotherapy, palliative chemotherapy and no anticancer treatment are presented. We propose multimodal care approaches that incorporate nutritional support, exercise, and anti-inflammatory agents, on a background of personalized oncology care and family-centred education. Collectively, the cases reveal that multimodal care is part of everyone's remit, often focuses on supported self-management, and demands buy-in from the patient and their family. Once operationalized, multimodal care approaches can be tested pragmatically, including alongside emerging pharmacological cachexia treatments.

SUMMARY

We demonstrate that multimodal care for cancer cachexia can be achieved using simple treatments and without a dedicated team of specialists. The sharing of advice between health professionals can help build collective confidence and expertise, moving towards a position in which every team member feels they can contribute towards multimodal care.

Variants of GSK3β and SFRP4 genes in Wnt signaling were not associated with osteonecrosis of the femoral head

Genome-wide association studies have identified that the gene variants in Wnt signaling associate with bone mineral density and fracture risk but the effects of the variants on the development of osteonecrosis of the femoral head (ONFH) have been unclear. Here, we analyzed the polymorphisms of 4 variants in GSK3β and SFRP4 genes of Wnt signaling and their association with the development of ONFH through Mass ARRAY^® platform in 200 ONFH patients and 177controls in Chinese population. Our results showed that the genotypes and allele frequencies of all variants detected in SFRP4 and GSK3β genes were not significantly different between patients and controls (p > 0.05); the correlation analysis between the 4 variants genotypes and gender, age at onset, etiological classification, unilateral or bilateral hip lesions, and clinical stages of ONFH, respectively, did not confirm significant association (p > 0.05) although age at onset in the minor homozygous(CC) carriers of SFRP4 rs1052981 (T/C) was a statistically younger tendency than that of the major homozygous (TT) or heterozygous (TC) of the SNP (p = 0.051); moreover, all haplotypes analyzed and their association with the clinical phenotypes of ONFH were also shown no statistical significance (p > 0.05).These results suggest that the 4 variants analyzed by this study in GSK3β and SFRP4 genes of Wnt signaling pathway are unlikely to be associated with susceptibility to ONFH.

Association of gene variants of transcription factors PPARγ, RUNX2, Osterix genes and COL2A1, IGFBP3 genes with the development of osteonecrosis of the femoral head in Chinese population

The molecular pathogenesis of osteonecrosis of the femoral head (ONFH) has been remained obscure so that its prevalence has been increasing in recent decades. Different transcription factors play critical roles in maintaining the balance between osteogenesis and adipogenesis. However, it has been unclear that the genes variants of the transcription factors exert the effects on the imbalance between steogenesis and adipogenesis during the development of ONFH. Here, we selected the 11SNPs from steogenesis, adipogenesis-specific transcription factors RUNX2, Osterix, and PPARγ genes, chondrogenesis or adipogenesis key factors COL2A1, IGFBP3 genes and analysed the genotypes, alleles, haplotypes and their association with the risk and clinical phenotypes of ONFH through Mass ARRAY® platformin in 200 ONFH patients and 177controls. The patients with ONFH (132 males, 68 females; age: 53.46±11.48yr) were consecutively enrolled at the Department of Orthopedics, the Second Clinical College of Jilin University, from March 2014 to June 2015 and were diagnosed and classified into 10 cases of stage II (5.6%), 54 cases of stage III (30.2%) and 115 cases (64.2%) of stage IV and alcohol-induced (71 cases (39.7%)), idiopathic (64 cases (34.0%)), and steroid-induced osteonecrosis (47 cases (26.3%)) subgroup, respectively. Our results showed that all models of logistical regression analysis, the co-dominants, dominants, and recessives of PPARγrs2920502, significantly associated with the increased risk of ONFH (p=0.004, p=0.013, p=0.016), respectively. Both the minor homozygous CC genotype and the allele C of rs2920502 were evidently correlated with the enhanced risk of ONFH (p=0.005, p=0.0005),respectively. The recessives models of IGFBP3rs2132572 (G/A) as well as RUNX2 rs3763190(G/A) were statistically associated with the higher ONFH risk, p=0.030, p=0.029, respectively; the minor homozygous(AA) of IGFBP3rs2132572 (G/A) was also related to the increased risk of bilateral hips lesions, p=0.039. Moreover, the ages on set of major homozygous(GG) and heterozygous(GT) of COL2A1rs2070739(G/A) were significantly younger than that of the minor homozygous(AA) of the SNP(p=0.008) while the A-T-G-A haplotype of COL2A1 gene revealed significant association with the decreased the risk of bilateral hip lesions, p=0.01, OR:0.258. More important, the serum HDL-c level and the ratio of LDL-c/HDL-c in the ONFH group were significantly decreased and increased compared with those of the control group (p=0.02, p=0.0001), respectively. Particularly, the CC genotype of PPARγ rs2920502 was statistically correlated with the enhanced serum TG level, p=0.011.These results suggest that the variants of PPARγ, RUNX2, COL2A1, and IGFBP3 genes closely associated with the development of ONFH.

Biomarkers of cancer cachexia

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

Body mass index change in gastrointestinal cancer and chronic obstructive pulmonary disease is associated with Dedicator of Cytokinesis 1

BACKGROUND

There have been a number of candidate gene association studies of cancer cachexia-related traits, but no genome-wide association study (GWAS) has been published to date. Cachexia presents in patients with a number of complex traits, including both cancer and COPD. The objective of the current investigation was to search for a shared genetic aetiology for change in body mass index (ΔBMI) among cancer and COPD by using GWAS data in the Framingham Heart Study.

METHODS

A linear mixed effects model accounting for age, sex, and change in smoking status was used to calculate ΔBMI in participants over 40 years of age with three consecutive BMI time points (n = 4162). Four GWAS of ΔBMI using generalized estimating equations were performed among 1085 participants with a cancer diagnosis, 204 with gastrointestinal (GI) cancer, 112 with lung cancer, and 237 with COPD to test for association with 418 365 single-nucleotide polymorphisms (SNPs).

RESULTS

Two SNPs reached a level of genome-wide significance (P < 5 × 10^-8 ) with ΔBMI: (i) rs41526344 within the CNTN4 gene, among COPD cases (β = 0.13, P = 4.3 × 10^-8 ); and (ii) rs4751240 in the gene Dedicator of Cytokinesis 1 (DOCK1) among GI cancer cases (β = 0.10, P = 1.9 × 10^-8 ). The DOCK1 SNP association replicated in the ΔBMI GWAS among COPD cases (β_meta-analyis  = 0.10, P_meta-analyis  = 9.3 × 10^-10 ). The DOCK1 gene codes for the dedicator of cytokinesis 1 protein, which has a role in myoblast fusion.

CONCLUSIONS

In sum, one statistically significant common variant in the DOCK1 gene was associated with ΔBMI in GI cancer and COPD cases providing support for at least partially shared aetiology of ΔBMI in complex diseases.

New genetic signatures associated with cancer cachexia as defined by low skeletal muscle index and weight loss

BACKGROUND

Cachexia affects the majority with advanced cancer. Based on current demographic and clinical factors, it is not possible to predict who will develop cachexia or not. Such variation may, in part, be due to genotype. It has recently been proposed to extend the diagnostic criteria for cachexia to include a direct measure of low skeletal muscle index (LSMI) in addition to weight loss (WL). We aimed to explore our panel of candidate single nucleotide polymorphism (SNPs) for association with WL +/- computerized tomography-defined LSMI. We also explored whether the transcription in muscle of identified genes was altered according to such cachexia phenotype METHODS: A retrospective cohort study design was used. Analysis explored associations of candidate SNPs with WL (n = 1276) and WL + LSMI (n = 943). Human muscle transcriptome (n = 134) was analysed using an Agilent platform.

RESULTS

Single nucleotide polymorphisms in the following genes showed association with WL alone: GCKR, LEPR, SELP, ACVR2B, TLR4, FOXO3, IGF1, CPN1, APOE, FOXO1, and GHRL. SNPs in LEPR, ACVR2B, TNF, and ACE were associated with concurrent WL + LSMI. There was concordance between muscle-specific expression for ACVR2B, FOXO1 and 3, LEPR, GCKR, and TLR4 genes and LSMI and/or WL (P < 0.05).

CONCLUSIONS

The rs1799964 in the TNF gene and rs4291 in the ACE gene are new associations when the definition of cachexia is based on a combination of WL and LSMI. These findings focus attention on pro-inflammatory cytokines and the renin-angiotensin system as biomarkers/mediators of muscle wasting in cachexia.

Cancer tolerance, resistance, pathogenicity and virulence: deconstructing the disease state

Immunologists have recently taken note of the fact that a host not only resists infection, but also exhibits a capacity to manage the pathology associated with such infection – a concept referred to as tolerance. Here we explore how the tolerance/resistance (T/R) framework can be implemented within an oncological context and explore a number of implications. In particular, the T/R framework distinguishes between pathology manifesting from extensive tumor burden, versus cancers intrinsically expressing a more pathogenic phenotype. Consequently, the T/R framework provides novel methodology in studying the nature of cancer pathology and for marker identification. Additionally, this framework may aid in redefining the therapeutic end point under suitable circumstances: establishing cancer as a chronic, manageable disease.

STAT3 in the systemic inflammation of cancer cachexia

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

Association between FTO gene polymorphism (rs9939609 T/A) and cancer risk: a meta-analysis

Obesity is a risk factor of cancer. Several genes have been found to play an important role in aetiology of obesity and tumourigenesis. Recently, some studies suggested that rs9939609 polymorphism might be significantly associated with cancer risk, while the results of some other studies were controversial. Databases with time limitation from January 1984 to April 2015 were searched. The pooled odds ratio (OR) with 95% confidence interval was calculated to assess the associations, and subgroup meta-analyses were performed according to the type of cancer and ethnicity of the study populations. Overall, the significant association between rs9939609 polymorphism and cancer risk was found in homozygote model and recessive model. As to subgroup classified by cancer type, there was significant association in endometrial cancer and pancreatic cancer, while no statistical significance was detected in other kind of cancers. Besides, in the subgroup analysis of ethnicity, our results indicated that rs9939609 polymorphism was significantly associated with cancer risk in Asians. The rs9939609 polymorphism may be involved the susceptibility of endometrial cancer and pancreatic cancer, especially in Asian populations. Thus, rs9939609 may be a potential biomarker in early diagnosis or gene therapy target of endometrial cancer and pancreatic cancer.

Exercise for cancer cachexia in adults: Executive summary of a Cochrane Collaboration systematic review

BACKGROUND

Cancer cachexia is a complex syndrome characterized by an ongoing loss of skeletal muscle mass and progressive functional impairment. A proactive management approach is recommended, including physical exercise to maintain function via modulation of muscle metabolism, insulin sensitivity and levels of inflammation. The review aimed to determine the safety, acceptability and effectiveness of exercise in adults with cancer cachexia. Secondary aims, subject to the data availability, were to compare effectiveness according to the characteristics of the study intervention or population.

METHODS

We sought randomised controlled trials (RCTs) in adults meeting international criteria for cancer cachexia, comparing a programme of exercise as a sole or adjunct intervention to usual care or an active control. CENTRAL, MEDLINE, EMBASE, DARE and HTA, ISI Web of Science, LILACS, PEDro, SciVerse SCOPUS, Biosis Previews PreMEDLINE and Open Grey databases were searched up to June 2014. Two authors independently assessed studies for eligibility.

RESULTS

We screened 3154 separate titles and abstracts, and reviewed 16 full-texts. Corresponding authors were contacted to determine if samples met cachexia staging criteria. Most authors did not explore this concept. No trial met review eligibility criteria. We were unable to perform a meta-analysis to determine any effects from exercise intervention.

CONCLUSION

Despite a strong rationale for the use of exercise, there is insufficient evidence to determine safety and effectiveness in patients with cancer cachexia. Findings from ongoing studies are awaited. Assessment of cachexia domains, ideally against international criteria, is required for future trials of exercise and supportive care interventions.