Oxidative stress and wasting in cancer

Tryptophan Modulation in Cancer-Associated Cachexia Mouse Models

Cancer cachexia is a multifactorial syndrome that interferes with treatment and reduces the quality of life and survival of patients. Currently, there is no effective treatment or biomarkers, and pathophysiology is not clear. Our group reported alterations on tryptophan metabolites in cachectic patients, so we aim to investigate the role of tryptophan using two cancer-associated cachexia syngeneic murine models, melanoma B16F10, and pancreatic adenocarcinoma that is KPC-based. Injected mice showed signs of cancer-associated cachexia as reduction in body weight and raised spleen weight, MCP1, and carbonilated proteins in plasma. CRP and Myostatin also increased in B16F10 mice. Skeletal muscle showed a decrease in quadriceps weight and cross-sectional area (especially in B16F10). Higher expression of atrophy genes, mainly Atrogin1, was also observed. Plasmatic tryptophan levels in B16F10 tumor-bearing mice decreased even at early steps of tumorigenesis. In KPC-injected mice, tryptophan fluctuated but were also reduced and in cachectic patients were significantly lower. Treatment with 1-methyl-tryptophan, an inhibitor of tryptophan degradation, in the murine models resulted in the restoration of plasmatic tryptophan levels and an improvement on splenomegaly and carbonilated proteins levels, while changes in plasmatic inflammatory markers were mild. After the treatment, CCR2 expression in monocytes diminished and lymphocytes, Tregs, and CD8+, were activated (seen by increased in CD127 and CD25 expression, respectively). These immune cell changes pointed to an improvement in systemic inflammation. While treatment with 1-MT did not show benefits in terms of muscle wasting and atrophy in our experimental setting, muscle functionality was not affected and central nuclei fibers appeared, being a feature of regeneration. Therefore, tryptophan metabolism pathway is a promising target for inflammation modulation in cancer-associated cachexia.

Influence of Preoperative Nutritional Status on Patients Who Undergo Upfront Surgery for Esophageal Squamous Cell Carcinoma

Few studies have focused on preoperative nutritional status of esophageal cancer patients eligible for upfront surgery. We aimed to investigate the association of preoperative nutritional status with prognosis of patients who undergo upfront surgery for esophageal cancer. A total of 274 patients who underwent upfront surgery for esophageal squamous cell carcinoma between January 2012 and December 2016 were eligible. Preoperative nutritional status was evaluated using prognostic nutritional index (PNI) scoring system, nutritional risk screening 2002 (NRS 2002), and controlling nutritional status. The median age was 63 years (interquartile range, 58-70) and 94.7% of patients were male. The pathological stages were Stage I-74.5% (204/274), Stage II-20.4% (56/274), and Stage III-5.1% (14/274). Multivariate analysis revealed that advanced stage, a low PNI, and a high NRS 2002 were independent predictors of overall survival. During median follow-up period of 55 mo, overall survival rates were lower in the high NRS 2002 group (P < 0.001). A high NRS 2002 score was associated with frequent postoperative complications, especially pneumonia and anastomosis site leakage (P = 0.003). The poor preoperative nutritional status with a high NRS 2002 is associated with postoperative complications as well as poor overall survival in patients with upfront surgery for esophageal cancer.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2022.2042573.

Metabolic Biomarkers for the Early Detection of Cancer Cachexia

Background: Cancer cachexia is a severe metabolic disorder characterized by progressive weight loss along with a dramatic loss in skeletal muscle and adipose tissue. Like cancer, cachexia progresses in stages starting with pre-cachexia to cachexia and finally to refractory cachexia. In the refractory stage, patients are no longer responsive to therapy and management of weight loss is no longer possible. It is therefore critical to detect cachexia as early as possible. In this study we applied a metabolomics approach to search for early biomarkers of cachexia.

Methods: Multi-platform metabolomics analyses were applied to the murine Colon-26 (C26) model of cachexia. Tumor bearing mice (n = 5) were sacrificed every other day over the 14-day time course and control mice (n = 5) were sacrificed every fourth day starting at day 2. Linear regression modeling of the data yielded metabolic trajectories that were compared with the trajectories of body weight and skeletal muscle loss to look for early biomarkers of cachexia.

Results: Weight loss in the tumor-bearing mice became significant at day 9 as did the loss of tibialis muscle. The loss of muscle in the gastrocnemius and quadriceps was significant at day 7. Reductions in amino acids were among the earliest metabolic biomarkers of cachexia. The earliest change was in methionine at day 4. Significant alterations in acylcarnitines and lipoproteins were also detected several days prior to weight loss.

Conclusion: The results of this study demonstrate that metabolic alterations appear well in advance of observable weight loss. The earliest and most significant alterations were found in amino acids and lipoproteins. Validation of these results in other models of cachexia and in clinical studies will pave the way for a clinical diagnostic panel for the early detection of cachexia. Such a panel would provide a tremendous advance in cachectic patient management and in the design of clinical trials for new therapeutic interventions.

Combined prognostic nutritional index and albumin-bilirubin grade to predict the postoperative prognosis of HBV-associated hepatocellular carcinoma patients

This study aims to evaluate the predictive value of the prognostic nutritional index (PNI) and albumin-bilirubin grade (ALBI) for the postoperative prognosis of hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC) patients undergoing radical hepatectomy (RH). Besides, we seek to identify novel prognosis indicators for HBV-HCC patients. Between April 2009 and March 2015, this work enrolled 868 patients diagnosed with HBV-HCC and undergoing RH in the Liver Surgery Department, West China Hospital, Sichuan University (WCHSU). The basic information, laboratory examination indicators, pathological reports, and follow-up data of patients were included. SPSS 22.0 statistical software was used for statistical data analyses. Platelet (PLT), alpha-fetoprotein (AFP), maximum diameter (max-D), number of tumors (Number), degree of differentiation (DD), Microvascular invasion situation (MVI), satellite focus situation (SF), PNI, and ALBI were the independent risk factors for both overall survival (OS) and disease-free survival (DFS) of HBV-HCC patients undergoing RH. Taking PNI = 46 and ALBI = - 2.80 as cut-off values, the OS and DFS of the PNI-high group were significantly higher than those of the PNI-low group. Meanwhile, the OS and DFS of the ALBI-low group were significantly higher than those of the ALBI-high group; the OS and DFS of the PNI-high + ALBI-low group were significantly higher than those of the PNI-low + ALBI-high group. Xie prognostic index (XPI) was the independent risk factor for both OS and DFS of HBV-HCC patients undergoing RH. The OS and DFS of the XPI-high group were significantly higher than those of the XPI-low group. This paper reveals that preoperative PNI and ALBI can predict the OS and DFS of HBV-HCC patients undergoing RH. Their impact on the prognosis of HBV-HCC patients is insignificant, however, it cannot be ignored. XPI can precisely predict the prognosis of HBV-HCC patients undergoing RH, nonetheless, its effect requires additional research for validation.

An Evaluation of Inflammatory and Nutritional Status of Breast Cancer Outpatients in a Tertiary Hospital in Nigeria

AIM

To assess the relationship between nutritional status and inflammatory markers of breast cancer patients, and to identify predictors of malnutrition in these patients.

METHODS

This is a cross-sectional study of 45 patients with breast cancer assessed between January and June 2018. Nutritional status was evaluated by objective and subjective methods. The inflammatory markers and inflammation-based scores evaluated were C-reactive protein (CRP), albumin, erythrocyte sedimentation rate (ESR), Glasgow Prognostic Score (GPS), CRP/albumin ratio, and Albumin/CRP ratio.

RESULTS

A total of 45 patients were evaluated. Majority of the patients have high levels of both CRP and ESR (73.3% and 86.7% respectively). More than 70% of the patients were well nourished. There was no significant association between CRP (P = 0.067), ESR (P = 0.094) and SGA (Subjective Global Assessment) categories. Albumin (P < 0.001), Albumin/CRP ratio (P = 0.002), CRP/albumin ratio (P = < 0.001), and GPS (P < 0.001) were significantly associated with SGA categories. On multivariate analysis, albumin (P < 0.001), Albumin/CRP ratio (P = 0.004), CRP/albumin ratio (P = 0.009), GPS (P = 0.01), and ECOG (P = 0.009) were the only markers independently related to malnutrition.

CONCLUSION

The inflammation-based scores were significantly associated with malnutrition and can be used as biochemical nutritional assessment tools in cancer patients.

Nutraceuticals and Exercise against Muscle Wasting during Cancer Cachexia

Cancer cachexia (CC) is a debilitating multifactorial syndrome, involving progressive deterioration and functional impairment of skeletal muscles. It affects about 80% of patients with advanced cancer and causes premature death. No causal therapy is available against CC. In the last few decades, our understanding of the mechanisms contributing to muscle wasting during cancer has markedly increased. Both inflammation and oxidative stress (OS) alter anabolic and catabolic signaling pathways mostly culminating with muscle depletion. Several preclinical studies have emphasized the beneficial roles of several classes of nutraceuticals and modes of physical exercise, but their efficacy in CC patients remains scant. The route of nutraceutical administration is critical to increase its bioavailability and achieve the desired anti-cachexia effects. Accumulating evidence suggests that a single therapy may not be enough, and a bimodal intervention (nutraceuticals plus exercise) may be a more effective treatment for CC. This review focuses on the current state of the field on the role of inflammation and OS in the pathogenesis of muscle atrophy during CC, and how nutraceuticals and physical activity may act synergistically to limit muscle wasting and dysfunction.

Muscle alterations in the development and progression of cancer-induced muscle atrophy: a review

Cancer cachexia-cancer-associated body weight and muscle loss-is a significant predictor of mortality and morbidity in cancer patients across a variety of cancer types. However, despite the negative prognosis associated with cachexia onset, there are no clinical therapies approved to treat or prevent cachexia. This lack of treatment may be partially due to the relative dearth of literature on mechanisms occurring within the muscle before the onset of muscle wasting. Therefore, the purpose of this review is to compile the current scientific literature on mechanisms contributing to the development and progression of cancer cachexia, including protein turnover, inflammatory signaling, and mitochondrial dysfunction. We define "development" as changes in cell function occurring before the onset of cachexia and "progression" as alterations to cell function that coincide with the exacerbation of muscle wasting. Overall, the current literature suggests that multiple aspects of cellular function, such as protein turnover, inflammatory signaling, and mitochondrial quality, are altered before the onset of muscle loss during cancer cachexia and clearly highlights the need to study more thoroughly the developmental stages of cachexia. The studying of these early aberrations will allow for the development of effective therapeutics to prevent the onset of cachexia and improve health outcomes in cancer patients.

Cancer Stem Cells: Emergent Nature of Tumor Emergency

A functional analysis of 167 genes overexpressed in Krebs-2 tumor initiating cells was performed. In the first part of the study, the genes were analyzed for their belonging to one or more of the three groups, which represent the three major phenotypic manifestation of malignancy of cancer cells, namely (1) proliferative self-sufficiency, (2) invasive growth and metastasis, and (3) multiple drug resistance. 96 genes out of 167 were identified as possible contributors to at least one of these fundamental properties. It was also found that substantial part of these genes are also known as genes responsible for formation and/or maintenance of the stemness of normal pluri-/multipotent stem cells. These results suggest that the malignancy is simply the ability to maintain the stem cell specific genes expression profile, and, as a consequence, the stemness itself regardless of the controlling effect of stem niches. In the second part of the study, three stress factors combined into the single concept of "generalized cellular stress," which are assumed to activate the expression of these genes, were defined. In addition, possible mechanisms for such activation were identified. The data obtained suggest the existence of a mechanism for the de novo formation of a pluripotent/stem phenotype in the subpopulation of "committed" tumor cells.

The predictive value of a preoperative systemic immune-inflammation index and prognostic nutritional index in patients with esophageal squamous cell carcinoma

Growing evidence indicates that systemic inflammation response and malnutrition status are correlated with survival in certain types of solid tumors. The aim of this study is to evaluate the association between the systemic immune-inflammation index (SII) and prognostic nutritional index (PNI) and overall survival (OS) in patients with esophageal squamous cell carcinoma (ESCC) after esophagectomy. A consecutive series of 655 patients with resected ESCC who underwent esophagectomy were enrolled in the retrospective study. The preoperative SII was defined as platelet × neutrophil/lymphocyte counts. The PNI was calculated as albumin concentration (g/L) + 5 × total lymphocyte count (10⁹ /L). The optimal cut-off values of SII, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and PNI were determined by receiver operating characteristic analysis. Survival analysis was performed using the Kaplan-Meier method with a log-rank test, followed by a multivariate Cox proportional hazards model. A high SII was significantly related to tumor size, histological type, invasion depth, and TNM stage (p < 0.05). A low PNI was significantly associated with age, tumor size, invasion depth, lymph node metastasis, and TNM stage (p < 0.05). Univariate analysis revealed that age, smoking history, tumor size, invasion depth, lymph node metastasis, SII, NLR, PLR, and PNI were predictors of OS (p < 0.05). Multivariate analysis identified age (p = 0.041), tumor size (p = 0.016), invasion depth (p < 0.001), lymph node metastasis (p < 0.001), SII (p = 0.033), and PNI (p = 0.022) as independent prognostic factors correlated with OS. There was a significant inverse relationship between the SII and PNI (r = 0.309; p < 0.001). The predictive value increased when the SII and PNI were considered in combination. Our results demonstrate that the preoperative high SII and low PNI are powerful indicators of aggressive biology and poor prognosis for patients with ESCC. The combination of SII and PNI can enhance the accuracy of prognosis.

Mitochondrial dynamics in cancer-induced cachexia

Cancer-induced cachexia has a negative impact on quality of life and adversely affects therapeutic outcomes and survival rates. It is characterized by, often severe, loss of muscle, with or without loss of fat mass. Insight in the pathophysiology of this complex metabolic syndrome and direct treatment options are still limited, which creates a research demand. Results from recent studies point towards a significant involvement of muscle mitochondrial networks. However, data are scattered and a comprehensive overview is lacking. This paper aims to fill existing knowledge gaps by integrating published data sets on muscle protein or gene expression from cancer-induced cachexia animal models. To this end, a database was compiled from 94 research papers, comprising 11 different rodent models. This was combined with four genome-wide transcriptome datasets of cancer-induced cachexia rodent models. Analysis showed that the expression of genes involved in mitochondrial fusion, fission, ATP production and mitochondrial density is decreased, while that of genes involved ROS detoxification and mitophagy is increased. Our results underline the relevance of including post-translational modifications of key proteins involved in mitochondrial functioning in future studies on cancer-induced cachexia.

Targeted overexpression of catalase to mitochondria does not prevent cardioskeletal myopathy in Barth syndrome

Barth Syndrome (BTHS) is an X-linked recessive disorder characterized by cardiomyopathy and muscle weakness. The underlying cause of BTHS is a mutation in the tafazzin (TAZ) gene, a key enzyme of cardiolipin biosynthesis. The lack of CL arising from loss of TAZ function results in destabilization of the electron transport system, promoting oxidative stress that is thought to contribute to development of cardioskeletal myopathy. Indeed, in vitro studies demonstrate that mitochondria-targeted antioxidants improve contractile capacity in TAZ-deficient cardiomyocytes. The purpose of the present study was to determine if resolving mitochondrial oxidative stress would be sufficient to prevent cardiomyopathy and skeletal myopathy in vivo using a mouse model of BTHS. To this end we crossed mice that overexpress catalase in the mitochondria (MCAT mice) with TAZ-deficient mice (TAZKD) to produce TAZKD mice that selectively overexpress catalase in the mitochondria (TAZKD+MCAT mice). TAZKD+MCAT mice exhibited decreased mitochondrial H₂O₂ emission and lipid peroxidation compared to TAZKD littermates, indicating decreased oxidative stress. Despite the improvements in oxidative stress, TAZKD+MCAT mice developed cardiomyopathy and mild muscle weakness similar to TAZKD littermates. These findings indicate that resolving oxidative stress is not sufficient to suppress cardioskeletal myopathy associated with BTHS.

Role of Oxidative Stress as Key Regulator of Muscle Wasting during Cachexia

Skeletal muscle atrophy is a pathological condition mainly characterized by a loss of muscular mass and the contractile capacity of the skeletal muscle as a consequence of muscular weakness and decreased force generation. Cachexia is defined as a pathological condition secondary to illness characterized by the progressive loss of muscle mass with or without loss of fat mass and with concomitant diminution of muscle strength. The molecular mechanisms involved in cachexia include oxidative stress, protein synthesis/degradation imbalance, autophagy deregulation, increased myonuclear apoptosis, and mitochondrial dysfunction. Oxidative stress is one of the most common mechanisms of cachexia caused by different factors. It results in increased ROS levels, increased oxidation-dependent protein modification, and decreased antioxidant system functions. In this review, we will describe the importance of oxidative stress in skeletal muscles, its sources, and how it can regulate protein synthesis/degradation imbalance, autophagy deregulation, increased myonuclear apoptosis, and mitochondrial dysfunction involved in cachexia.

Oxidative Stress and Fitness Changes in Cancer Patients after Exercise Training

INTRODUCTION

The purpose of this study was to determine the effect of an exercise intervention (EX) on muscular strength, cardiorespiratory fitness (CRF), and oxidative stress in cancer survivors compared with a nonexercising cancer control group (CON).

METHODS

Fifteen cancer patients and seven age-matched individuals with no history of cancer (NC) participated in this study. A blood draw and assessments of muscular strength and CRF were administered to cancer survivors within 6 wk of completing radiation or chemotherapy, and again 10 wk later. Eight cancer patients completed a 10-wk supervised exercise intervention, whereas seven continued standard care. Baseline oxidative stress was compared between cancer patients and the NC group. Changes in plasma protein carbonyls, 8-OHdG, and Trolox equivalent antioxidant capacity were compared between groups using repeated-measures ANOVA, and correlations between fitness and oxidative stress changes were evaluated.

RESULTS

Baseline antioxidant capacity was significantly lower, and plasma protein carbonyls were significantly higher in cancer patients compared with NC (P = 0.001). EX had a significant increase in antioxidant capacity (P < 0.001) and decrease in protein carbonyls (P = 0.023), whereas CON did not. Improvements in composite arm (41%, P = 0.002) and leg strength (34%, P = 0.008), isometric handgrip strength (11%, P = 0.015), and V˙O2peak (16%, P = 0.018) were significant in EX but not in CON. 8-OHdG changes were significantly correlated with changes in V˙O2peak (r = -0.89, P < 0.001), arm strength (r = -0.67, P = 0.004), and leg strength (r = -0.56, P = 0.019).

CONCLUSION

A whole-body exercise intervention for cancer survivors may be an effective method of concurrently increasing muscular strength, CRF, and antioxidant capacity while decreasing markers of oxidative stress.

Walker 256 tumor-bearing rats demonstrate altered interstitial cells of Cajal. Effects on ICC in the Walker 256 tumor model

BACKGROUND

Cachexia is a significant problem in patients with cancer. The effect of cancer on interstitial cells of Cajal (ICC) and neurons of the gastrointestinal tract have not been studied previously. Although supplementation with L-glutamine 2% may have beneficial effects in cancer-related cachexia, and be protective of ICC in models of oxidative stress such as diabetes, its effects on ICC in cancer have also not been studied.

METHODS

Twenty-eight male Wistar rats were divided into four groups: control (C), control supplemented with L-glutamine (CG), Walker 256 tumor (WT), and Walker 256 tumor supplemented with L-glutamine (WTG). Rats were implanted with tumor cells or injected with saline in the right flank. After 14 days, the jejunal tissues were collected and processed for immunohistochemical techniques including whole mounts and cryosections and Western blot analysis.

KEY RESULTS

Tumor-bearing rats demonstrate reduced numbers of Myenteric ICC and deep muscular plexus ICC and yet increased Ano1 protein expression and enhanced ICC networks. In addition, there is more nNOS protein expressed in tumor-bearing rats compared to controls. L-glutamine treatment had a variety of effects on ICC that may be related to the disease state and the interaction of ICC and nNOS neurons. Regardless, L-glutamine reduced the size of tumors and also tumor-induced cachexia that was not due to altered food intake.

CONCLUSIONS & INFERENCES

There are significant effects on ICC in the Walker 256 tumor model. Although supplementation with L-glutamine has differential and complex effects of ICC, it reduces tumor size and tumor-associated cachexia, which supports its beneficial therapeutic role in cancer.

Contribution of Neuroinflammation to the Pathogenesis of Cancer Cachexia

Inflammation characterizes the course of acute and chronic diseases and is largely responsible for the metabolic and behavioral changes occurring during the clinical journey of patients. Robust data indicate that, during cancer, functional modifications within brain areas regulating energy homeostasis contribute to the onset of anorexia, reduced food intake, and increased catabolism of muscle mass and adipose tissue. In particular, functional changes are associated with increased hypothalamic concentration of proinflammatory cytokines, which suggests that neuroinflammation may represent the adaptive response of the brain to peripheral challenges, including tumor growth. Within this conceptual framework, the vagus nerve appears to be involved in conveying alert signals to the hypothalamus, whereas hypothalamic serotonin appears to contribute to triggering catabolic signals.

Prognostic nutritional index predicts survival and correlates with systemic inflammatory response in advanced pancreatic cancer

BACKGROUND

Recent studies have implied a prognostic value of the prognostic nutritional index (PNI) in certain types of human cancers. However, the value of PNI for predicting survival in patients with pancreatic cancer remains unknown. The goal of this study was to investigate the predictive significance of PNI in patients with advanced pancreatic cancer.

METHODS

A total of 321 consecutive patients with pathologically-confirmed locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) were retrospectively recruited between January 2011 and August 2013. The patients were divided into a test set (n = 110) and a validation set (n = 211). We evaluated the association between PNI and overall survival (OS). The relationship between PNI and systemic inflammatory response markers, including the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lymphocyte/monocyte ratio (LMR) was also assessed. In addition, the associations between PNI and the TNF-α were analyzed.

RESULTS

Kaplan-Meier analyses showed that a low PNI correlated significantly with a shorter OS in patients with advanced pancreatic cancer (190 days for patients with a low PNI vs. 290 days for patients with a high PNI, log-rank = 12.566, P < 0.001). Multivariate analysis identified PNI as an independent prognostic factor for OS (hazard ratio [HR]: 0.627, 95% confidence interval [CI]: 0.453-0.868, P = 0.003). PNI also correlated positively with NLR and PLR and negatively with LMR. Additionally, patients with a low PNI exhibited high levels of TNF-α.

CONCLUSIONS

Our results confirm that PNI is associated with the systemic inflammatory response and can be used to predict survival in advanced pancreatic cancer.

Cancer cachexia update in head and neck cancer: Pathophysiology and treatment

The pathophysiology of cancer cachexia remains complex. A comprehensive literature search was performed up to April 2013 using PubMed, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and the Google search engine. In this review, we focus on the different mediators of impaired anabolism and upregulated catabolism that alter the skeletal muscle homeostasis resulting in the wasting of cancer cachexia. We present recent evidence of targeted treatment modalities from clinical trials along with their potential mechanisms of action. We also report on the most current evidence from randomized clinical trials using multimodal treatments in patients with cancer cachexia, but also the evidence from head and neck cancer-specific trials. A more complete understanding of the pathophysiology of the syndrome may lead to more effective targeted therapies and improved outcomes for patients.

Laparotomy in mice induces blood cell expression of inflammatory and stress genes

Surgical trauma induces immune and stress responses although its effects on postsurgical inflammatory and stress gene expression remain poorly characterized. This study sought to improve current scientific knowledge by investigating the effects of laparotomy on mouse blood cell inflammatory and stress gene expression. Three-month-old male C57BL/6J mice were subjected to 2% isoflurane or 2% isoflurane with laparotomy and sacrificed 4 h postintervention. Blood was collected and blood cell expression of 158 genes central to inflammatory and stress responses was assayed using quantitative polymerase chain reaction arrays. Mice subjected to isoflurane with laparotomy, compared with mice receiving isoflurane alone, had >2-fold upregulation of genes in inflammation (Osm, IL1rn, IL1b, and Csf1), oxidative stress (Hmox1), heat shock (Hspa1b), growth arrest (Cdkn1a), and DNA repair (Ugt1a2). These genes demonstrated similar expression patterns by Pearson correlation and cluster analysis. Thus, laparotomy induces coordinated, postsurgical blood cell expression of unique inflammatory and stress genes whose roles in influencing surgical outcomes need further investigation.

Prognostic value of scores based on malnutrition or systemic inflammatory response in patients with metastatic or recurrent gastric cancer

Cancer patients are frequently affected by malnutrition and weight loss, which affects their prognosis, length of hospital stay, health care costs, quality of life and survival. Our aim was to assess the prognostic value of different scores based on malnutrition or systemic inflammatory response in 91 metastatic or recurrent gastric cancer patients considered for palliative chemotherapy at the Masaryk Memorial Cancer Institute. We investigated their overall survival according to the following measures: Onodera's Prognostic Nutritional Index (OPNI), Glasgow Prognostic Score (GPS), nutritional risk indicator (NRI), Cancer Cachexia Study Group (CCSG), as previously defined, and a simple preadmission weight loss. The OPNI, GPS, and CCSG provided very significant prognostic values for survival (log-rank test P value < 0.001). For example, the median survival for patients with GPS 0 was 12.3 mo [95% confidence interval (CI): 7.7-16.7], whereas the median survival for patients with GPS 2 was only 2.9 mo (95% CI: 1.9-4.8). A significantly worse survival of malnourished patients was also suggested by a multivariate model. The values of GPS, OPNI, and CCSG represent useful tools for the evaluation of patients' prognosis and should be part of a routine evaluation of patients to provide a timely nutrition support.

Concurrent evolution of cancer cachexia and heart failure: bilateral effects exist

Cancer cachexia is defined as a multifactorial syndrome of involuntary weight loss characterized by an ongoing loss of skeletal muscle mass and progressive functional impairment. It is postulated that cardiac dysfunction/atrophy parallels skeletal muscle atrophy in cancer cachexia. Cardiotoxic chemotherapy may additionally result in cardiac dysfunction and heart failure in some cancer patients. Heart failure thus may be a consequence of either ongoing cachexia or chemotherapy-induced cardiotoxicity; at the same time, heart failure can result in cachexia, especially muscle wasting. Therefore, the subsequent heart failure and cardiac cachexia can exacerbate the existing cancer-induced cachexia. We discuss these bilateral effects between cancer cachexia and heart failure in cancer patients. Since cachectic patients are more susceptible to chemotherapy-induced toxicity overall, this may also include increased cardiotoxicity of antineoplastic agents. Patients with cachexia could thus be doubly unfortunate, with cachexia-related cardiac dysfunction/heart failure and increased susceptibility to cardiotoxicity during treatment. Cardiovascular risk factors as well as pre-existing heart failure seem to exacerbate cardiac susceptibility against cachexia and increase the rate of cardiac cachexia. Hence, chemotherapy-induced cardiotoxicity, cardiovascular risk factors, and pre-existing heart failure may accelerate the vicious cycle of cachexia-heart failure. The impact of cancer cachexia on cardiac dysfunction/heart failure in cancer patients has not been thoroughly studied. A combination of serial echocardiography for detection of cachexia-induced cardiac remodeling and computed tomography image analysis for detection of skeletal muscle wasting would appear a practical and non-invasive approach to develop an understanding of cardiac structural/functional alterations that are directly related to cachexia.

Clinical perspective on oxidative stress in sporadic amyotrophic lateral sclerosis

Sporadic amyotrophic lateral sclerosis (ALS) is one of the most devastating neurological diseases; most patients die within 3 to 4 years after symptom onset. Oxidative stress is a disturbance in the pro-oxidative/antioxidative balance favoring the pro-oxidative state. Autopsy and laboratory studies in ALS indicate that oxidative stress plays a major role in motor neuron degeneration and astrocyte dysfunction. Oxidative stress biomarkers in cerebrospinal fluid, plasma, and urine are elevated, suggesting that abnormal oxidative stress is generated outside of the central nervous system. Our review indicates that agricultural chemicals, heavy metals, military service, professional sports, excessive physical exertion, chronic head trauma, and certain foods might be modestly associated with ALS risk, with a stronger association between risk and smoking. At the cellular level, these factors are all involved in generating oxidative stress. Experimental studies indicate that a combination of insults that induce modest oxidative stress can exert additive deleterious effects on motor neurons, suggesting that multiple exposures in real-world environments are important. As the disease progresses, nutritional deficiency, cachexia, psychological stress, and impending respiratory failure may further increase oxidative stress. Moreover, accumulating evidence suggests that ALS is possibly a systemic disease. Laboratory, pathologic, and epidemiologic evidence clearly supports the hypothesis that oxidative stress is central in the pathogenic process, particularly in genetically susceptive individuals. If we are to improve ALS treatment, well-designed biochemical and genetic epidemiological studies, combined with a multidisciplinary research approach, are needed and will provide knowledge crucial to our understanding of ALS etiology, pathophysiology, and prognosis.

Proteomic profiling of the hypothalamus in a mouse model of cancer-induced anorexia-cachexia

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.

Cancer cachexia pathophysiology and translational aspect of herbal medicine

About half of all cancer patients show a syndrome of cachexia, characterized by anorexia and loss of adipose tissue and skeletal muscle mass. Numerous cytokines have been postulated to play a role in the etiology of cancer cachexia. Cytokines can elicit effects that mimic leptin signaling and suppress orexigenic ghrelin and neuropeptide Y signaling, inducing sustained anorexia and cachexia not accompanied by the usual compensatory response. Furthermore, cytokines have been implicated in the induction of cancer-related muscle wasting. In particular, tumor necrosis factor-alpha, interleukin-1, interleukin-6 and interferon-gamma have been implicated in the induction of cancer-related muscle wasting. Cytokine-induced skeletal muscle wasting is probably a multifactorial process, which involves a depression in protein synthesis, an increase in protein degradation or a combination of both. Cancer patients suffer from the reduction in physical function, tolerance to anti-cancer therapy and survival, while many effective chemotherapeutic agents for cancer are burdened by toxicities that can reduce patient's quality of life or hinder their effective use. Herbal medicines have been widely used to help improve such conditions. Recent studies have shown that herbal medicines such as rikkunshito enhance ghrelin signaling and consequently improve nausea, appetite loss and cachexia associated with cancer or cancer chemotherapy, which worsens the quality of life and life expectancy of the patients. The multicomponent herbal medicines capable of targeting multiple sites could be useful for future drug discovery. Mechanistic studies and identification of active compounds could lead to new discoveries in biological and biomedical sciences.

Cancer cachexia--pathophysiology and management

About half of all cancer patients show a syndrome of cachexia, characterized by anorexia and loss of adipose tissue and skeletal muscle mass. Cachexia can have a profound impact on quality of life, symptom burden, and a patient's sense of dignity. It is a very serious complication, as weight loss during cancer treatment is associated with more chemotherapy-related side effects, fewer completed cycles of chemotherapy, and decreased survival rates. Numerous cytokines have been postulated to play a role in the etiology of cancer cachexia. Cytokines can elicit effects that mimic leptin signaling and suppress orexigenic ghrelin and neuropeptide Y (NPY) signaling, inducing sustained anorexia and cachexia not accompanied by the usual compensatory response. Furthermore, cytokines have been implicated in the induction of cancer-related muscle wasting. Cytokine-induced skeletal muscle wasting is probably a multifactorial process, which involves a protein synthesis inhibition, an increase in protein degradation, or a combination of both. The best treatment of the cachectic syndrome is a multifactorial approach. Many drugs including appetite stimulants, thalidomide, cytokine inhibitors, steroids, nonsteroidal anti-inflammatory drugs, branched-chain amino acids, eicosapentaenoic acid, and antiserotoninergic drugs have been proposed and used in clinical trials, while others are still under investigation using experimental animals. There is a growing awareness of the positive impact of supportive care measures and development of promising novel pharmaceutical agents for cachexia. While there has been great progress in understanding the underlying biological mechanisms of cachexia, health care providers must also recognize the psychosocial and biomedical impact cachexia can have.

Timing of antioxidant supplementation is critical in improving anorexia in an experimental model of cancer

Increased oxidative stress may contribute to cancer anorexia, which could be ameliorated by antioxidant supplementation. methylcholanthrene (MCA) sarcoma-bearing Fisher rats were studied. After tumour inoculation, rats were randomly assigned to standard diet (CTR group, n = 6), or to an antioxidant-enriched diet (AOX group, n = 8). Eight more rats (STD-AOX group) switched from standard to antioxidant diet when anorexia developed. At the end of the study, food intake (FI, g/d), body weight and tumour weight (g) were recorded, and plasma samples were obtained. On day 16, anorexia has appeared only in CTR and STD-AOX animals. At the end of the study, FI in AOX animals was still higher than in the other groups (p = 0.08). No differences in body and tumour weights were observed among groups. However, hydrogen peroxide and interleukin-1β levels were significantly reduced only in AOX rats. Data obtained suggest that early antioxidant supplementation improves cancer anorexia, ameliorates oxidative stress and reduces inflammation.

Oxidative damage and carcinogenesis

Oxygen is an essential element to conduct life processes but some of the metabolic byproducts e.g. reactive oxygen species (ROS), are toxic for living organisms. Endogenous ROS are produced e.g. reduction of dioxygen; some exogenous sources of radicals also exist, including nicotine and ionizing radiation. Reactive oxygen species include superoxide anion, hydroxyl radical, singlet oxygen, hydrogen peroxide and hypochlorous acid.

Carcinogenesis is a multistep process. The exact reasons for the development of cancer are still unknown. Many factors contribute to the development of carcinogenesis, one of which is oxidative stress. Oxidative stress is defined as an imbalance between oxidizing agents (pro-oxidants) and antioxidants, agents that protect biomolecules against injury by pro-oxidants. When reactive oxygen species are overproduced it can damage nucleic acids, proteins and lipids. ROS are considered as a significant class of carcinogens participating in cancer initiation, promotion and progression.

Randomized phase III clinical trial of a combined treatment with carnitine + celecoxib ± megestrol acetate for patients with cancer-related anorexia/cachexia syndrome

BACKGROUND & AIMS

A phase III, randomized non-inferiority study was carried out to compare a two-drug combination (including nutraceuticals, i.e. antioxidants) with carnitine + celecoxib ± megestrol acetate for the treatment of cancer-related anorexia/cachexia syndrome (CACS): the primary endpoints were increase of lean body mass (LBM) and improvement of total daily physical activity. Secondary endpoint was: increase of physical performance tested by grip strength and 6-min walk test.

METHODS

Sixty eligible patients were randomly assigned to: arm 1, L-carnitine 4 g/day + Celecoxib 300 mg/day or arm 2, L-carnitine 4 g/day + celecoxib 300 mg/day + megestrol acetate 320 mg/day, all orally. All patients received as basic treatment polyphenols 300 mg/day, lipoic acid 300 mg/day, carbocysteine 2.7 g/day, Vitamin E, A, C. Treatment duration was 4 months. Planned sample size was 60 patients.

RESULTS

The results did not show a significant difference between tre atment arms in both primary and secondary endpoints. Analysis of changes from baseline showed that LBM (by dual-energy X-ray absorptiometry and by L3 computed tomography) increased significantly in both arms as well as physical performance assessed by 6MWT. Toxicity was quite negligible and comparable between arms.

CONCLUSIONS

The results of the present study showed a non-inferiority of arm 1 (two-drug combination) vs arm 2 (two-drug combination + megestrol acetate). Therefore, this simple, feasible, effective, safe, low cost with favorable cost-benefit profile, two-drug approach could be suggested in the clinical practice to implement CACS treatment.

Antigenotoxic and antioxidant activities of palmarosa and citronella essential oils

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oils of palmarosa and citronella have been extensively used in ancient Indian and South-east Asian traditional medicines.

AIM OF THE STUDY

These essential oils have been reported to exhibit antimicrobial, anti parasitic effects against bacteria, yeasts, filamentous fungi, and viruses. In the present study the oils were tested for their potential antigenotoxic and antioxidant properties in human lymphocyte cells.

MATERIALS AND METHODS

The antigenotoxic effect on human lymphocyte cells (measurement of cell viability, DNA damage) was studied using trypan blue dye exclusion test, plasmid pBR322 DNA strand scission, and comet assay. Anti-oxidant activity was evaluated by DPPH(+) free radical scavenging and lipid peroxidation assay.

RESULTS

The essential oils showed a good antigenotoxic activity against methyl methanesulphonate (MMS) and hydrogen peroxide. In addition, a significant dose dependent antioxidant activity was observed.

CONCLUSION

Our data provide evidence that support the usage of palmarosa and citronella essential oils in traditional herbal preparations. They can constitute a natural source of a new and safe antioxidant.

l-carnitine and cancer cachexia: Clinical and experimental aspects

Cancer cachexia is a multifaceted syndrome characterized, among many symptoms, by extensive muscle wasting. Chronic systemic inflammation, partly triggered and sustained by cytokines, as well as increased oxidative stress contributes to the pathogenesis of this complex metabolic disorder. l-carnitine plays a central role in the metabolism of fatty acids and shows important antioxidant and anti-inflammatory properties. Systemic carnitine depletion has been described in several diseases, and it is characterized by fatigue, muscle weakness, and decreased tolerance to metabolic stress. In cachectic cancer patients, low serum carnitine levels have been reported, and this change has been suggested to play an important contributory role in the development of cachexia. Based on these data, carnitine supplementation has been tested in preliminary studies concerning human cachexia, resulting in improved fatigue and quality of life. We present here a review of clinical and experimental evidence regarding the use of carnitine supplementation in the management of cancer cachexia.

Effects of inactivity on human muscle glutathione synthesis by a double-tracer and single-biopsy approach

Oxidative stress is often associated to inactivity-mediated skeletal muscle atrophy. Glutathione is one of the major antioxidant systems stimulated, both at muscular and systemic level, by activation of oxidative processes. We measured changes in glutathione availability, oxidative stress induction and the extent of atrophy mediated by 35 days of experimental bed rest in vastus lateralis muscle of healthy human volunteers. To assess muscle glutathione synthesis, we applied a novel single-biopsy and double-tracer ([(2)H(2)]glycine and [(15)N]glycine) approach based on evaluation of steady-state precursor incorporation in product. The correlations between the traditional (multiple-samples, one-tracer) and new (one-sample, double-tracer infusion) methods were analysed in erythrocytes by Passing-Bablok and Altman-Bland tests. Muscle glutathione absolute synthesis rate increased following bed rest from 5.5 ± 1.1 to 11.0 ± 1.5 mmol (kg wet tissue)(-1) day(-1) (mean ± S.E.M.; n = 9; P = 0.02) while glutathione concentration failed to change significantly. Bed rest induced vastus lateralis muscle atrophy, as assessed by pennation angle changes measured by ultrasonography (from 18.6 ± 1.0 to 15.3 ± 0.9 deg; P = 0.01) and thickness changes (from 2.3 ± 0.2 to 1.9 ± 0.1 cm; P < 0.001). Moreover, bed rest increased protein oxidative stress, as measured by muscle protein carbonylation changes (from 0.6 ± 0.1 to 1.00 ± 0.1 Oxydized-to-total protein ratio; P < 0.04). In conclusion, we developed in erythrocytes a new minimally invasive method to determine peptide synthesis rate in human tissues. Application of the new method to skeletal muscle suggests that disuse atrophy is associated to oxidative stress induction as well as to compensatory activation of the glutathione system.

Nuclear magnetic resonance in conjunction with functional genomics suggests mitochondrial dysfunction in a murine model of cancer cachexia

Cancer patients commonly suffer from cachexia, a syndrome in which tumors induce metabolic changes in the host that lead to massive loss in skeletal muscle mass. Using a preclinical mouse model of cancer cachexia, we tested the hypothesis that tumor inoculation causes a reduction in ATP synthesis and genome-wide aberrant expression in skeletal muscle. Mice implanted with Lewis lung carcinomas were examined by in vivo³¹P nuclear magnetic resonance (NMR). We examined ATP synthesis rate and the expression of genes that play key-regulatory roles in skeletal muscle metabolism. Our in vivo NMR results showed reduced ATP synthesis rate in tumor-bearing (TB) mice relative to control (C) mice, and were cross-validated with whole genome transcriptome data showing atypical expression levels of skeletal muscle regulatory genes such as peroxisomal proliferator activator receptor γ coactivator 1 ß (PGC-1ß), a major regulator of mitochondrial biogenesis and, mitochondrial uncoupling protein 3 (UCP3). Aberrant pattern of gene expression was also associated with genes involved in inflammation and immune response, protein and lipid catabolism, mitochondrial biogenesis and uncoupling, and inadequate oxidative stress defenses, and these effects led to cachexia. Our findings suggest that reduced ATP synthesis is linked to mitochondrial dysfunction, ultimately leading to skeletal muscle wasting and thus advance our understanding of skeletal muscle dysfunction suffered by cancer patients. This study represents a new line of research that can support the development of novel therapeutics in the molecular medicine of skeletal muscle wasting. Such therapeutics would have wide-spread applications not only for cancer patients, but also for many individuals suffering from other chronic or endstage diseases that exhibit muscle wasting, a condition for which only marginally effective treatments are currently available.

Skeletal muscle wasting in cachexia and sarcopenia: molecular pathophysiology and impact of exercise training

Skeletal muscle is the most abundant tissue in the human body, and the maintenance of its mass is essential to ensure basic function as locomotion, strength and respiration. The decision to synthesize or to break down skeletal muscle proteins is regulated by a network of signaling pathways that transmit external stimuli to intracellular factors regulating gene transcription. The tightly regulated balance of muscle protein breakdown and synthesis is disturbed in several distinct myopathies, but also in two pathologies: sarcopenia and cachexia. In recent years, it became evident that in these two muscle wasting disorders specific regulating molecules are increased in expression (e.g. members of the ubiquitin-proteasome system, myostatin, apoptosis inducing factors), whereas other factors (e.g. insulin-like growth factor 1) are down-regulated. So far, not many treatment options to fight the muscle loss are available. One of the most promising approaches is exercise training that, due to its multifactorial effects, can act on several signaling pathways. Therefore, this review will concentrate on specific alterations discussed in the current literature that are present in the skeletal muscle of both muscle wasting disorders. In addition, we will focus on exercise training as an intervention strategy.

Saffron suppresses oxidative stress in DMBA-induced skin carcinoma: A histopathological study

Cancer chemoprevention is the use of natural, synthetic or biological substances to reverse or prevent the development of cancer. Saffron is a naturally derived plant product that acts as an antispasmodic, diaphoretic, carminative, emmenagogic and sedative. Our aim in this study was to investigate the chemopreventive effect of aqueous saffron on chemically induced skin carcinogenesis using a histopathological approach. Mice were divided into five groups: carcinogen control (CC), normal control (NC) and saffron-treated Groups A, B and C. Groups A, B, C and CC mice received three topical applications of 7,12 dimethylbenz[a]anthracene (DMBA) followed by croton oil on shaven dorsal skin for 8 weeks. NC mice received topical skin applications of the vehicle, acetone, only. Saffron infusion was fed orally to three groups of mice either before (Group A) or after (Group C) or both before and after (Group B) DMBA applications. The activities of antioxidant enzymes glutathione-S transferase (GST), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in liver tissue samples taken at 0, 6, 10 and 12 weeks from all groups were assessed. Standard histological examination of skin demonstrated a beneficial action of saffron in mice where saffron treatments were given both before and after the induction of skin carcinogenesis. Saffron ingestion inhibited the formation of skin papillomas in animals and simultaneously reduced their size. In conclusion, saffron inhibits DMBA-induced skin carcinoma in mice when treated early. This may be due, at least in part, to the induction of cellular defense systems.

SENP3-mediated de-conjugation of SUMO2/3 from promyelocytic leukemia is correlated with accelerated cell proliferation under mild oxidative stress

Small ubiquitin-like modifier (SUMO) 2/3 is known to conjugate to substrates in response to a variety of cellular stresses. However, whether and how SUMO2/3-specific proteases are involved in de-conjugation under cell stress is unclear. Here, we show that low doses of hydrogen peroxide (H(2)O(2)) induce an increase of the SENP3 protein, which removes SUMO2/3 from promyelocytic leukemia (PML). Low dose H(2)O(2) causes SENP3 to co-localize with PML bodies and reduces the number of PML bodies in a SENP3-dependent manner. Furthermore, de-conjugation of SUMO2/3 from PML is responsible for the accelerated cell proliferation caused by low dose H(2)O(2). Knocking down PML promotes basal cell proliferation as expected. This can be reversed by reconstitution with wild-type PML but not its mutant lacking SUMOylation, indicating that only the SUMOylated PML can play an inhibitory role for cell proliferation. Thus, SENP3 appears to be a key mediator in mild oxidative stress-induced cell proliferation via regulation of the SUMOylation status of PML. Furthermore, SENP3 is over-accumulated in a variety of primary human cancers including colon adenocarcinoma in which PML is hypo-SUMOylated. These results reveal an important role of SENP3 and the SUMOylation status of PML in the regulation of cell proliferation under oxidative stress.

Tryptophan in wasting diseases: at the crossing between immune function and behaviour

PURPOSE OF REVIEW

Wasting diseases are characterized by progressive deterioration of nutritional status that negatively influences patients' outcome. The better understanding of the pathogenic mechanisms of wasting may lead to effective therapies. Tryptophan metabolism has unique features suggesting a critical role in influencing human metabolism under normal and pathological conditions.

RECENT FINDINGS

During disease, inflammatory response favours the local depletion of the essential amino acid tryptophan, thereby inhibiting cellular proliferation. Tryptophan depletion may also mediate immunotolerance to foreign antigens. In contrast, brain accumulation of tryptophan contributes to wasting by increasing oxidative stress and hypothalamic serotonin neurotransmission, and thereby triggering the onset of sickness behaviour followed by depressive-like behaviour.

SUMMARY

Tryptophan metabolism is critical in mediating a number of important biological responses. Restoring tryptophan metabolism may well result in enhanced recovery from disease.

Cyclooxygenase-2 inhibitors and antioxidants in the treatment of cachexia

PURPOSE OF REVIEW

Cancer cachexia is increasingly becoming a critical component in the comprehensive approach to cancer patients influencing morbidity, mortality and quality of life. Therefore its pathophysiology and the main contributing factors have been investigated with the aim of developing effective therapies. Reported findings highlight the role of chronic inflammation and oxidative stress in the onset of cancer cachexia.

RECENT FINDINGS

Chronic inflammation, one of the main features of cancer cachexia, triggers the overproduction of proinflammatory cytokines playing a major role in the pathogenesis of systemic symptoms of cachexia; therefore, antiinflammatory drugs such as cyclooxygenase-2 inhibitors could break the 'vicious circle' leading to the onset and worsening of this devastating syndrome. Likewise, oxidative stress, almost always accompanying cancer cachexia, may be counteracted by effective antioxidant treatments. The most relevant recent clinical approaches addressing these targets are reported.

SUMMARY

Fairly advanced clinical data on efficacy of cyclooxygenase-2 inhibitors and antioxidants in advanced cancer patients are promising, but the best way to administer and combine them with other agents, the optimal dose and timing remain uncertain. However, because cachexia is a multifactorial syndrome, therapeutic approaches targeting a single contributing factor may be inadequate. A rational treatment should thus be multitargeted addressing all key contributing factors.

Calpain-1 is required for hydrogen peroxide-induced myotube atrophy

Recent reports suggest numerous roles for cysteine proteases in the progression of skeletal muscle atrophy due to disuse or disease. Nonetheless, a specific requirement for these proteases in the progression of skeletal muscle atrophy has not been demonstrated. Therefore, this investigation determined whether calpains or caspase-3 is required for oxidant-induced C2C12 myotube atrophy. We demonstrate that exposure to hydrogen peroxide (25 microM H2O2) induces myotube oxidative damage and atrophy, with no evidence of cell death. Twenty-four hours of exposure to H2O2 significantly reduced both myotube diameter and the abundance of numerous proteins, including myosin (-81%), alpha-actinin (-40%), desmin (-79%), talin (-37%), and troponin I (-80%). Myotube atrophy was also characterized by increased cleavage of the cysteine protease substrate alphaII-spectrin following 4 h and 24 h of H2O2 treatment. This degradation was blocked by administration of the protease inhibitor leupeptin (10 microM). Using small interfering RNA transfection of mature myotubes against the specific proteases calpain-1, calpain-2, and caspase-3, we demonstrated that calpain-1 is required for H2O2-induced myotube atrophy. Collectively, our data provide the first evidence for an absolute requirement for calpain-1 in the development of skeletal muscle myotube atrophy in response to oxidant-induced cellular stress.

Effect of garlic on lipid peroxidation and antioxidation enzymes in DMBA-induced skin carcinoma

OBJECTIVE

Naturally occurring phytochemicals display an active cancer preventive strategy to inhibit, delay, or reverse human carcinogenesis. Studies have indicated that certain daily-consumed dietary phytochemicals have cancer protective effects mediated by carcinogens. Lipid peroxide plays a detrimental role in all cancers including skin carcinogenesis. Garlic, a phytochemical, has acquired a special position in the folklore of many cultures as a formidable prophylactic and therapeutic medicinal agent. In this report, we pursue the chemopreventive effect of aqueous garlic on skin carcinogenesis.

METHODS

"Swiss albino mice" were divided into five groups depending on the combination of skin cancer-inducing 7,12-dimethylbenz[a]anthracene and garlic treatments. Histology of the affected skin and biochemical assays for lipid peroxide, catalase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase were performed to demonstrate the effect of garlic in mice. Immunoblotting was performed with cyclo-oxygenase-2, p53, and caspase-3 to demonstrate expressions of the respective proteins in skin lysates.

RESULTS

Garlic extracts inhibited the oxidative modification of lipids, thus protecting cells from injury by the oxidized molecules. The best chemopreventive action of garlic was observed in mice in which garlic treatment was performed before and after the induction of skin carcinogenesis. Garlic ingestion delayed formation of skin papillomas in animals and simultaneously decreased the size and number of papillomas, which was also reflected in the skin histology of the mice treated.

CONCLUSION

The protective effects against skin cancer elicited by garlic in mice are believed to be due at least in part to the induction cellular defense systems.

Neural control of the anorexia-cachexia syndrome

The anorexia-cachexia syndrome is a debilitating clinical condition characterizing the course of chronic diseases, which heavily impacts on patients' morbidity and quality of life, ultimately accelerating death. The pathogenesis is multifactorial and reflects the complexity and redundancy of the mechanisms controlling energy homeostasis under physiological conditions. Accumulating evidence indicates that, during disease, disturbances of the hypothalamic pathways controlling energy homeostasis occur, leading to profound metabolic changes in peripheral tissues. In particular, the hypothalamic melanocortin system does not respond appropriately to peripheral inputs, and its activity is diverted largely toward the promotion of catabolic stimuli (i.e., reduced energy intake, increased energy expenditure, possibly increased muscle proteolysis, and adipose tissue loss). Hypothalamic proinflammatory cytokines and serotonin, among other factors, are key in triggering hypothalamic resistance. These catabolic effects represent the central response to peripheral challenges (i.e., growing tumor, renal, cardiac failure, disrupted hepatic metabolism) that are likely sensed by the brain through the vagus nerve. Also, disease-induced changes in fatty acid oxidation within hypothalamic neurons may contribute to the dysfunction of the hypothalamic melanocortin system. Ultimately, sympathetic outflow mediates, at least in part, the metabolic changes in peripheral tissues. Other factors are likely involved in the pathogenesis of the anorexia-cachexia syndrome, and their role is currently being elucidated. However, available evidence shows that the constellation of symptoms characterizing this syndrome should be considered, at least in part, as different phenotypes of common neurochemical/metabolic alterations in the presence of a chronic inflammatory state.

The cytokine basis of cachexia and its treatment: are they ready for prime time?

Cachexia is a hypercatabolic condition that is often associated with the terminal stages of many diseases, in which the patient's resting metabolic rate is high and loss of muscle and fat tissue mass occur at an alarming rate. The patient also usually has concurrent anorexia, amplifying the wasting syndrome that is cachexia. The greater the extent of cachexia (regardless of underlying disease), the worse the prognosis. Efforts to treat cachexia over the years have fallen short of satisfactorily reversing the wasting syndrome. This article reviews the pathophysiology of cachexia, enumerating the different pro-inflammatory cytokines that contribute to the syndrome and attempting to illustrate their interwoven pathways. We also review the different treatments that have been explored, as well as the recent literature addressing the use of anti-cytokine therapy to treat cachexia.