Exercise, cachexia, and cancer therapy: a molecular rationale

Cachexia in Cancer Patients: Systematic Literature Review

Introduction Cachexia in cancer patients, especially in advanced stage, is recently known as an emerging problem. Cachexia occurs in about half of all patients with neoplastic disease. The diagnosis of cachexia needs comprehensive evaluation of body weight and body composition for several months. Cachexia will give negative impacts such as increased mortality, chemotoxicity, and decreased quality of life. Here, we review the current evidence describing the definition, stages, mechanisms, diagnosis and treatment of cachexia in cancer patients.

Methods We identified 75 studies and/or review articles evaluating cachexia and weight loss in cancer patients by searching PubMed and EMBASE databases.

Results Cachexia is reported across all stages and types of cancers. The most recent definition of cachexia is reported in a 2011 paper by International Consensus. The mechanism of cachexia in cancer is complex and involved many factors which elaborate together to produce cachexia. The diagnostic evaluation and cut-off measurement of cachexia, especially in cancer varied across studies. The loss of weight that happens during chemotherapy will make a poor prognosis. Cachexia can worsen chemotherapy toxicity. Combination of dietary modification and exercise with supplementation of medication that control appetite and inflammation are important in the management of cachexia in cancer patients.

Conclusion Patients with cancer are the population at risk for developing cachexia before and after chemotherapy. Cachexia diagnosis needs evaluation of body weight and body composition. Nonpharmacological treatments, such as dietary modification and physical exercise, are the best strategy to reduce cachexia in cancer patients.

Nutritional Aspect of Cancer Care in Medical Oncology Patients

PURPOSE

Awareness of advances in the nutritional aspects of cancer care and translation of this information into clinical practice are important for oncology practitioners to effectively couple oncologic and nutritional approaches throughout the cancer journey. The goal of this consensus statement by a panel of medical oncologists was to provide practical and implementable guidance addressing nutritional aspects of cancer care from the perspective of the medical oncologist.

METHODS

A panel of medical oncologists agreed on a series of statements supported by scientific evidence and expert clinical opinion.

FINDINGS

Participating experts emphasized that both poor nutritional intake and metabolic alterations underlie cancer-related malnutrition. The use of liquid and high energy-dense oral nutritional supplements may enable better patient compliance, whereas higher efficacy is more likely with the use of pharmaconutrient-enriched oral nutritional supplements in terms of improved weight, lean body mass, functional status, and quality of life, as well as better tolerance to antineoplastic treatment. A multimodal approach is currently believed to be the best option to counteract the catabolism leading to cancer-related malnutrition; this treatment is scheduled in parallel with anticancer therapies and includes nutritional interventions, multitarget drug therapies, and exercise and rehabilitation programs. Participating experts emphasized the role of the oncologist as a reference professional figure in the coordination of nutritional care for patients with cancer within the context of complex and different clinical scenarios, particularly for permissive-adjunctive nutritional support.

IMPLICATIONS

This review article provides practical guidance addressing major nutritional aspects of cancer care from the medical oncologist's perspective. Thus, this document is expected to assist oncology practitioners in terms of awareness of advances in the nutritional aspects of cancer care and translation of this information into their clinical practice to effectively couple oncologic and nutritional approaches as part of the continuum of care for patients with cancer.

Exercise training counteracts urothelial carcinoma-induced alterations in skeletal muscle mitochondria phospholipidome in an animal model

Cancer associated body wasting is the cause of physical disability, reduced tolerance to anticancer therapy and reduced survival of cancer patients and, similarly to cancer, its incidence is increasing. There is no cure for this clinical condition, and the pathophysiological process involved is largely unknown. Exercise training appears as the gold standard non-pharmacological therapy for the management of this wasting syndrome. Herein we used a lipidomics approach based on liquid chromatography coupled with high-resolution mass spectrometry (LC-HR-MS) to study the effect of exercise in the modulation of phospholipids profile of mitochondria isolated from gastrocnemius muscle of a pre-clinical model of urothelial carcinoma-related body wasting (BBN induced), submitted to 13 weeks of treadmill exercise after diagnosis. Multivariate analysis showed a close relationship between the BBN exercise group and both control groups (control sedentary and control exercise), while the BBN sedentary group was significantly separated from the control groups and the BBN exercise group. Univariate statistical analysis revealed differences mainly in phosphatidylserine (PS) and cardiolipin (CL), although some differences were also observed in phosphatidylinositol (PI, LPI) and phosphatidylcholine (PC) phospholipids. PS with shorter fatty acyl chains were up-regulated in the BBN sedentary group, while the other species of PS with longer FA and a higher degree of unsaturation were down-regulated, but the BBN exercise group was mostly similar to control groups. Remarkably, exercise training prevented these alterations and had a positive impact on the ability of mitochondria to produce ATP, restoring the healthy phospholipid profile. The remodelling of mitochondria phospholipid profile in rats with urothelial carcinoma allowed confirming the importance of the lipid metabolism in mitochondria dysfunction in cancer-induced skeletal muscle remodelling. The regulation of phospholipid biosynthetic pathways observed in the BBN exercise group supported the current perspective that exercise is an adequate therapeutic approach for the management of cancer-related muscle remodeling.

Resistance exercise attenuates skeletal muscle oxidative stress, systemic pro-inflammatory state, and cachexia in Walker-256 tumor-bearing rats

The aim of this study was to investigate the effects of resistance exercise training (RET) on oxidative stress, systemic inflammatory markers, and muscle wasting in Walker-256 tumor-bearing rats. Male (Wistar) rats were divided into 4 groups: sedentary controls (n = 9), tumor-bearing (n = 9), exercised (n = 9), and tumor-bearing exercised (n = 10). Exercised and tumor-bearing exercised rats were exposed to resistance exercise of climbing a ladder apparatus with weights tied to their tails for 6 weeks. The physical activity of control and tumor-bearing rats was confined to the space of the cage. After this period, tumor-bearing and tumor-bearing exercised animals were inoculated subcutaneously with Walker-256 tumor cells (11.0 × 10⁷ cells in 0.5 mL of phosphate-buffered saline) while control and exercised rats were injected with vehicle. Following inoculation, rats maintained resistance exercise training (exercised and tumor-bearing exercised) or sedentary behavior (control and tumor-bearing) for 12 more days, after which they were euthanized. Results showed muscle wasting in the tumor-bearing group, with body weight loss, increased systemic leukocytes, and inflammatory interleukins as well as muscular oxidative stress and reduced mTOR signaling. In contrast, RET in the tumor-bearing exercised group was able to mitigate the reduced body weight and muscle wasting with the attenuation of muscle oxidative stress and systemic inflammatory markers. RET also prevented loss of muscle strength associated with tumor development. RET, however, did not prevent the muscle proteolysis signaling via FBXO32 gene messenger RNA expression in the tumor-bearing group. In conclusion, RET performed prior tumor implantation prevents cachexia development by attenuating tumor-induced systemic pro-inflammatory condition with muscle oxidative stress and muscle damage.

Inflammation as Cause for Scar Cancers of the Lung

The molecular and cellular basis of inflammation has become a topic of great interest of late because of the association between mechanisms of inflammation and risk for cancer. Inflammatory-mediated events, such as the production of reactive oxygen species (ROS), the activation of growth factors (for wound repair), and the altering of signal-transduction processes to activate cell-proliferation (to replace necrotic/apoptotic tissue cells), events that also can occur independently of inflammation, are all considered to be components of risk for a variety of cancers. Using scar cancer of the lung as an example, mechanisms of inflammation associated with recurring infections with Mycobacterium tuberculosisare discussed in the context that they may, in fact, be the major or sole cause of a cancer. Production of ROS, prostaglandins, leukotrienes, and cytokines in pulmonary tissues is greatly enhanced due to a cell-mediated immune response against macrophages infected with M. tuberculosis. These responses lead to the extensive fibrosis associated with recurring infections, possibly leading to decreased clearance of lymph and lymph-associated particles from the infected region. They also will enhance rates of cell division by inhibiting synthesis of P21, leading to enhanced progression from G0 arrest to G1 phase, from G1 to Sphase, and from G2 to M phase of the cell cycle. By increasing rates of oxidative DNA damage and inhibiting apoptosis by enhancing synthesis of BCL-2, mutagenesis of progeny cells is enhanced, and these effects coupled with enhanced angiogenesis stimulated by COX-2 products lead to an environment that is highly conducive to tumorigenesis. Based on the evidence, it appears that but for an inflammatory response to recurring infections, some cases of scar cancer would not exist. By making appropriate lifestyle and dietary changes, a variety of anti-inflammatory effects can be produced, which should attenuate inflammation-induced risk for cancer.

Skeletal muscle wasting and renewal: a pivotal role of myokine IL-6

Adult skeletal tissue is composed of heterogeneous population of cells that constantly self-renew by means of a controlled process of activation and proliferation of tissue-resident stem cells named satellite cells. Many growth factors, cytokines and myokines produced by skeletal muscle cells play critical roles in local regulation of the inflammatory process and skeletal muscle regeneration during different pathological conditions. IL-6 is a pleiotropic cytokine released in large amount during infection, autoimmunity and cancer. Low levels of IL-6 can promote activation of satellite cells and myotube regeneration while chronically elevated production promote skeletal muscle wasting. These distinct effects may be explained by a crosstalk of the IL-6/IL-6 receptor and gp130 trans-signaling pathway that oppose to regenerative and anti-inflammatory of the classical IL-6 receptor signaling pathway. Here we discuss on potential therapeutic strategies using monoclonal antibodies to IL-6R for the treatment of skeletal muscle wasting and cachexia. We also highlight on the IL-6/JAK/STAT and FGF/p38αβ MAPK signaling pathways in satellite cell activation and the use of protein kinase inhibitors for tailoring and optimizing satellite cell proliferation during the skeletal muscle renewal. Future investigations on the roles of the IL-6 classical and trans-signaling pathways in both immune and non-immune cells in skeletal muscle tissue will provide new basis for therapeutic approaches to reverse atrophy and degeneration of skeletal muscles in cancer and inflammatory diseases.

Premature Atherosclerotic Cardiovascular Disease in Childhood Cancer Survivors

Survival rates of childhood cancer have increased over the last 30 years, revealing a population with unique characteristics and risks. The effects of radiation and cardiotoxic chemotherapy predispose these children to both early and late cardiovascular disease. Cranial radiation also increases the likelihood of growth hormone deficiency, which leads to metabolic disturbances. Childhood cancer survivors are less likely to be active than their healthy siblings, and have a lower aptitude for physical activity. These issues are additive to the usual risks experienced by the general population, thereby significantly increasing the likelihood of premature cardiovascular disease. Early and regular screening and risk factor management in this population is recommended.

Cancer cachexia, mechanism and treatment

It is estimated that half of all patients with cancer eventually develop a syndrome of cachexia, with anorexia and a progressive loss of adipose tissue and skeletal muscle mass. Cancer cachexia is characterized by systemic inflammation, negative protein and energy balance, and an involuntary loss of lean body mass. It is an insidious syndrome that not only has a dramatic impact on patient quality of life, but also is associated with poor responses to chemotherapy and decreased survival. Cachexia is still largely an underestimated and untreated condition, despite the fact that multiple mechanisms are reported to be involved in its development, with a number of cytokines postulated to play a role in the etiology of the persistent catabolic state. Existing therapies for cachexia, including orexigenic appetite stimulants, focus on palliation of symptoms and reduction of the distress of patients and families rather than prolongation of life. Recent therapies for the cachectic syndrome involve a multidisciplinary approach. Combination therapy with diet modification and/or exercise has been added to novel pharmaceutical agents, such as Megestrol acetate, medroxyprogesterone, ghrelin, omega-3-fatty acid among others. These agents are reported to have improved survival rates as well as quality of life. In this review, we will discuss the emerging understanding of the mechanisms of cancer cachexia, the current treatment options including multidisciplinary combination therapies, as well an update on new and ongoing clinical trials.

Cancer cachexia prevention via physical exercise: molecular mechanisms

Cancer cachexia is a debilitating consequence of disease progression, characterised by the significant weight loss through the catabolism of both skeletal muscle and adipose tissue, leading to a reduced mobility and muscle function, fatigue, impaired quality of life and ultimately death occurring with 25-30 % total body weight loss. Degradation of proteins and decreased protein synthesis contributes to catabolism of skeletal muscle, while the loss of adipose tissue results mainly from enhanced lipolysis. These mechanisms appear to be at least, in part, mediated by systemic inflammation. Exercise, by virtue of its anti-inflammatory effect, is shown to be effective at counteracting the muscle catabolism by increasing protein synthesis and reducing protein degradation, thus successfully improving muscle strength, physical function and quality of life in patients with non-cancer-related cachexia. Therefore, by implementing appropriate exercise interventions upon diagnosis and at various stages of treatment, it may be possible to reverse protein degradation, while increasing protein synthesis and lean body mass, thus counteracting the wasting seen in cachexia.

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.

Delivering care to long-term adult survivors of hematopoietic cell transplantation

This review highlights long-term and late consequences of hematopoietic cell transplantation (HCT) as well as strategies to manage or prevent complications that are more prevalent after HCT than most other cancer treatments. Chronic graft-versus-host disease stands out as a unique late effect of allogeneic HCT that is not seen after other types of cancer treatment. However, many other complications seen after solid tumor treatments are also common after HCT, including infections, second cancers, bone loss, and cardiovascular, pulmonary, renal, and endocrine dysfunction. Symptoms and syndromes that are reported after HCT include sexual dysfunction, cognitive problems, fatigue, insomnia, musculoskeletal symptoms, emotional distress, anger, and depression. Addressing these complex potential or actual complications requires diligent routine health care to intervene early or, when possible, to prevent late complications. To accomplish early detection and prevention of life-threatening complications, HCT survivors should undergo an annual comprehensive physical examination that includes screening for functional and psychosocial consequences of treatment and encouraging healthy lifestyle behaviors. Clinicians can link survivors to numerous online, print, and video resources to help them advocate for their health needs.

Evaluation of a social cognitive theory-based email intervention designed to influence the physical activity of survivors of breast cancer

OBJECTIVE

The aim of this study is to evaluate a 12-week social cognitive theory (SCT)-based email intervention designed to influence the physical activity of survivors of breast cancer.

METHODS

Seventy-four volunteers (intervention group, n = 36; control group, n = 38) were recruited by mass email and written letter solicitation. Participants completed a series of online questionnaires measuring demographic characteristics, physical activity readiness, level of physical activity and selected SCT variables at baseline, 6 and 12 weeks. The intervention group received email messages based on SCT designed specifically for breast cancer survivors and targeting physical activity. For the first 6 weeks of the intervention, participants assigned to the intervention group received messages weekly, from weeks 7 to 12, participants received messages every other week and had access to an e-counselor. The control group did not receive email messages, nor did they have access to an e-counselor.

RESULTS

Significant differences in levels of self-reported vigorous physical activity were found between groups at 6 and 12 weeks. Significant differences were also found for self-reported moderate physical activity at 12 weeks.

CONCLUSION

Email-based interventions based on SCT can significantly influence levels of self-reported physical activity of breast cancer survivors.

Exercise and Cancer Treatment Symptoms in 408 Newly Diagnosed Older Cancer Patients

While the benefits of exercise for managing cancer-and treatment-related side effects has been shown among various populations of cancer survivors, a relative dearth of information exists among older cancer patients. OBJECTIVES: To determine the prevalence of exercise participation during and after primary cancer treatment in older (≥65 years) and the oldest (≥80 years) cancer patients and to examine the relationships between exercise, symptoms, and self-rated health (SRH). MATERIALS AND METHODS: 408 newly diagnosed older cancer patients (mean age=73, range=65-92) scheduled to receive chemotherapy and/or radiation therapy reported symptoms and SRH prior to, during, and 6 months after treatment, and exercise participation during and following treatment. RESULTS: Forty-six percent of older and 41% of the oldest patients reported exercising during treatment. Sixty percent of older and 68% of the oldest patients reported exercising in the 6 months thereafter. Older patients who exercised during treatment reported less shortness of breath and better SRH during treatment, and better SRH following treatment. The oldest patients who exercised during treatment reported less memory loss and better SRH during treatment and less fatigue and better SRH following treatment. The oldest patients who exercised following treatment reported less fatigue, skin problems, and total symptom burden following treatment. CONCLUSION: These data suggest a willingness of older cancer patients to attempt exercise during and after treatment. Exercise during these times is associated with less severe symptoms; further clinical research examining the efficacy of formal exercise interventions to reduce symptoms and improve SRH in older cancer patients is needed.

Hypothalamic inflammation is reversed by endurance training in anorectic-cachectic rats

Aim

We tested the effects of a cancer cachexia-anorexia sydrome upon the balance of anti and pro-inflammatory cytokines in the hypothalamus of sedentary or trained tumour-bearing (Walker-256 carcinosarcoma) rats.

Methods

Animals were randomly assigned to a sedentary control (SC), sedentary tumour-bearing (ST), and sedentary pair-fed (SPF) groups or, exercised control (EC), exercised tumour-bearing (ET) and exercised pair-fed (EPF) groups. Trained rats ran on a treadmill (60%VO_2max) for 60 min/d, 5 days/wk, for 8 wks. We evaluated food intake, leptin and cytokine (TNF-α, IL1β) levels in the hypothalamus.

Results

The cumulative food intake and serum leptin concentration were reduced in ST compared to SC. Leptin gene expression in the retroperitoneal adipose tissue (RPAT) was increased in SPF in comparison with SC and ST, and in the mesenteric adipose tissue (MEAT) the same parameter was decreased in ST in relation to SC. Leptin levels in RPAT and MEAT were decreased in ST, when compared with SC. Exercise training was also able to reduce tumour weight when compared to ST group. In the hypothalamus, IL-1β and IL-10 gene expression was higher in ST than in SC and SPF. Cytokine concentration in hypothalamus was higher in ST (TNF-α and IL-1β, p < 0.05), compared with SC and SPF. These pro-inflammatory cytokines concentrations were restored to control values (p < 0.05), when the animals were submitted to endurance training.

Conclusion

Cancer-induced anorexia leads towards a pro-inflammatory state in the hypothalamus, which is prevented by endurance training which induces an anti-inflammatory state, with concomitant decrease of tumour weight.

Activity level, apoptosis, and development of cachexia in Apc(Min/+) mice

Criteria for diagnosing cachexia in adults include unintentional loss in body weight, decreased strength, fatigue, anorexia, and low muscle mass. Cachexia is also associated with systemic inflammation, altered metabolism, and anemia. The Apc(Min/+) mouse is a model of cachexia directly related to intestinal tumor burden and subsequent chronic inflammation. These mice also demonstrate muscle weakness, fatigue, decreased volitional activity, and elevated circulating IL-6 levels. The purpose of this study was to determine the time course of changes in physical activity and their relationship to anemia, muscle apoptosis, and muscle mass and body mass loss during cachexia. A subset of male Apc(Min/+) mice were given access to voluntary activity wheels from 5 to 26 wk of age, while sedentary male Apc(Min/+) mice were housed in cages lacking wheels. At the study's end mice were stratified by cachectic symptoms. Severely cachectic mice had decreased wheel running performance at 15 wk of age, while anemia and body weight loss were not present until 18 wk of age. Severely cachectic mice had lower hemoglobin levels compared with mildly cachectic mice at 13, 18, and 22 wk of age. Severely cachectic mice also demonstrated threefold more BCL2-associated X protein (BAX) protein in the gastrocnemius muscle at 26 wk of age compared with mildly cachectic mice. In sedentary Apc(Min/+) mice at 26 wk of age anemia was present, and markers of apoptosis were induced in severely cachectic muscle. Proapoptotic protein expression was induced in both red and white portions of gastrocnemius muscle as well as in soleus muscle of severely cachectic mice compared with mildly cachectic mice. These data demonstrate that decrements in wheel running performance precede loss of body mass and that inherent muscle oxidative capacity is not protective against muscle apoptosis.

A biobehavioral model for the study of exercise interventions in cancer-related fatigue

Cancer-related fatigue (CRF) is a multifactorial, biobehavioral phenomenon experienced by the majority of persons with cancer. It has negative consequences on the individual's physical functioning and quality of life. An array of biological, psychobehavioral, and functional mechanisms contributes to its occurrence. A relatively large number of studies have examined the effect of physical exercise on CRF over the past few decades. Most of these studies did not specifically examine the effect of physical exercise on the biobehavioral mechanisms underlying CRF. For the most part, these studies have not been guided by a consistent theoretical model. Consequently, the mechanisms by which exercise may ameliorate CRF are not fully elucidated. A theoretical model incorporating fatigue-related biobehavioral variables that could be affected by physical exercise will allow for effective knowledge development in this area and could lead to the development and refinement of exercise protocols that specifically target these mechanisms. Thus, the purpose of this paper is to present a comprehensive theoretical model to guide future research on the effectiveness of exercise interventions in CRF. The proposed model incorporates the biological, psychobehavioral, and functional variables implicated in the induction of CRF.

Effect of endurance training upon lipid metabolism in the liver of cachectic tumour-bearing rats

The syndrome of cancer cachexia is accompanied by several alterations in lipid metabolism, and the liver is markedly affected. Previous studies showed that moderate exercise training may prevent liver fat accumulation through diminished delivery of lipids to the liver, increased hepatic oxidation and increased incorporation of triacylglycerol (TAG) into very low density lipoprotein (VLDL). Our aim was to examine the influence of moderate intensity training (8 weeks) upon TAG content, VLDL assembly and secretion, apolipoprotein B (apoB) and microsomal transfer protein (MTP) gene expression in the liver of cachectic tumour-bearing rats. Animals were randomly assigned to a sedentary control (SC), sedentary tumour-bearing (ST) or exercise-trained control (EC) or to an exercise trained tumour-bearing (ET) group. Trained rats ran on a treadmill (60% VO(2max)) for 60 min day(-1), 5 day week(-1), for 8 weeks. TAG content and the rate of VLDL secretion (followed for 3 h), as well as mRNA expression of apoB and MTP, and total cholesterol, VLDL-TAG, VLDL-cholesterol, high density lipoprotein cholesterol (HDL-cholesterol) and tumour weight were evaluated. VLDL-cholesterol showed a decrease in ST (p < 0.05) in relation to SC. Serum TAG, VLDL-TAG and tissue TAG content were all increased in ST (p < 0.01), when compared with SC. ST showed a lower rate of VLDL secretion (p < 0.05) and reduced expression of apoB (p < 0.001) and MTP (p < 0.001), when compared with SC. These parameters were restored to control values (p < 0.05) when the animals were submitted to the exercise training protocol. Tumour weight decreased 10-fold after training (p < 0.001). It is possible to affirm, therefore, that endurance training promoted the re-establishment of lipid metabolism in cachectic tumour-bearing animals, especially in relation to VLDL secretion and assembly.

Muscle wasting and interleukin-6-induced atrogin-I expression in the cachectic Apc ( Min/+ ) mouse

Interleukin-6 (IL-6) is necessary for cachexia in Apc ( Min/+ ) mice, but the mechanisms inducing this myofiber wasting have not been established. The purpose of this study was to examine gastrocnemius muscle wasting in the Apc ( Min/+ ) mouse and to determine IL-6 regulated mechanisms contributing to muscle loss. Gastrocnemius type IIB mean fiber cross-sectional area (CSA) from Apc ( Min/+ ) mice decreased 32% between 13 and 22 weeks of age. Apc ( Min/+ ) mice lacking IL-6 did not have type IIB fiber atrophy, while overexpression of circulating IL-6 exacerbated the loss of type IIB fiber CSA in Apc ( Min/+ ) mice. Muscle Atrogin-I mRNA expression was induced at least ninefold at 18 and 22 weeks of age compared to 13-week-old mice. Atrogin-I gene expression was also induced by overexpression of circulating IL-6. These data suggest that high circulating IL-6 levels induce type IIB fiber CSA loss in Apc ( Min/+ ) mice, and circulating IL-6 is sufficient to regulate Atrogin-I gene expression in cachectic mice.

Endurance training modulates lymphocyte function in rats with post-MI CHF

PURPOSE

Exercise training restores innate immune system cell function in post-myocardial infarction (post-MI) rats. However, studies of the involvement of lymphocyte (Ly) in the setting of the congestive heart failure (CHF) are few. To address this issue, we investigated the function of Ly obtained from cervical lymph nodes from post-MI CHF rats submitted to treadmill running training.

METHODS

Twenty-five male Wistar rats were randomly assigned to the following groups: rats submitted to ligation of the left coronary artery, which were sedentary (MI-S, N = 7, only limited activity) or trained (MI-T, N = 6, on a treadmill (0% grade at 13-20 m.m) for 60 min.d, 5 d.wk, for 8-10 wk); or sham-operated rats, which were sedentary (sham-S, N = 6) or trained (sham-T, N = 6). The incorporation of [2-C]-thymidine by Ly cultivated in the presence of concanavalin A (Con A) and lipopolysaccharide (LPS), cytokine production by Ly cultivated in the presence of phytohemagglutinin (PHA), and plasma concentration of glutamine were assessed in all groups, 48 h after the last exercise session.

RESULTS

Proliferative capacity was increased, following incubation with Con-A in the MI groups, when compared with the sham counterparts. When incubated in the presence of PHA, MI-S produced more IL-4 (96%) than sham-S (P < 0.001). The training protocol induced a 2.2-fold increase in the production of interleukin-2 (P < 0.001) of the cells obtained from the cervical lymph nodes of MI-T, compared with MI-S.

CONCLUSION

The moderate endurance training protocol caused an increase in IL-2 production, and a trend toward the reversion of the Th1/Th2 imbalance associated with IL-4 production increased in the post-MI CHF animal model.

Interleukin-6 and cachexia in ApcMin/+ mice

The Apc(Min/+) mouse has a mutation in the Apc tumor suppressor gene and develops intestinal polyps, beginning at 4 wk of age. This mouse develops cachexia by 6 mo, characterized by significant loss of muscle and fat tissue. The purpose of the present study was to determine the role of circulating interleukin-6 (IL-6) and the polyp burden for the development of cachexia in Apc(Min/+) mice. At 26 wk of age, mice exhibiting severe cachectic symptoms had a 61% decrease in gastrocnemius muscle weight, complete loss of epididymal fat, a 10-fold increase in circulating IL-6 levels, and an 89% increase in intestinal polyps compared with mildly cachectic animals. Apc(Min/+)/IL-6(-/-) mice did not lose gastrocnemius muscle mass or epididymal fat pad mass while overall polyp number decreased by 32% compared with Apc(Min/+) mice. Plasmid-based IL-6 overexpression in Apc(Min/+)/IL-6(-/-) mice led to a decrease in gastrocnemius muscle mass and epididymal fat pad mass and increased intestinal polyp burden. IL-6 overexpression did not induce cachexia in non-tumor-bearing mice. These data demonstrate that IL-6 is necessary for the onset of adipose and skeletal muscle wasting in the Apc(Min/+) mouse and that circulating IL-6 can regulate Apc(Min/+) mouse tumor burden.

Cardiovascular risk reduction in high-risk pediatric patients: a scientific statement from the American Heart Association Expert Panel on Population and Prevention Science; the Councils on Cardiovascular Disease in the Young, Epidemiology and Prevention, Nutrition, Physical Activity and Metabolism, High Blood Pressure Research, Cardiovascular Nursing, and the Kidney in Heart Disease; and the Interdisciplinary Working Group on Quality of Care and Outcomes Research

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Oxidative stress, chronic disease, and muscle wasting

Underlying the pathogenesis of chronic disease is the state of oxidative stress. Oxidative stress is an imbalance in oxidant and antioxidant levels. If an overproduction of oxidants overwhelms the antioxidant defenses, oxidative damage of cells, tissues, and organs ensues. In some cases, oxidative stress is assigned a causal role in disease pathogenesis, whereas in others the link is less certain. Along with underlying oxidative stress, chronic disease is often accompanied by muscle wasting. It has been hypothesized that catabolic programs leading to muscle wasting are mediated by oxidative stress. In cases where disease is localized to the muscle, this concept is easy to appreciate. Transmission of oxidative stress from diseased remote organs to skeletal muscle is thought to be mediated by humoral factors such as inflammatory cytokines. This review examines the relationship between oxidative stress, chronic disease, and muscle wasting, and the mechanisms by which oxidative stress acts as a catabolic signal.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Curcumin protects against radiation-induced acute and chronic cutaneous toxicity in mice and decreases mRNA expression of inflammatory and fibrogenic cytokines

PURPOSE

To determine whether curcumin ameliorates acute and chronic radiation skin toxicity and to examine the expression of inflammatory cytokines (interleukin [IL]-1, IL-6, IL-18, IL-1Ra, tumor necrosis factor [TNF]-alpha, and lymphotoxin-beta) or fibrogenic cytokines (transforming growth factor [TGF]-beta) during the same acute and chronic phases.

METHODS AND MATERIALS

Curcumin was given intragastrically or intraperitoneally to C3H/HeN mice either: 5 days before radiation; 5 days after radiation; or both 5 days before and 5 days after radiation. The cutaneous damage was assessed at 15-21 days (acute) and 90 days (chronic) after a single 50 Gy radiation dose was given to the hind leg. Skin and muscle tissues were collected for measurement of cytokine mRNA.

RESULTS

Curcumin, administered before or after radiation, markedly reduced acute and chronic skin toxicity in mice (p < 0.05). Additionally, curcumin significantly decreased mRNA expression of early responding cytokines (IL-1 IL-6, IL-18, TNF-alpha, and lymphotoxin-beta) and the fibrogenic cytokine, TGF-beta, in cutaneous tissues at 21 days postradiation.

CONCLUSION

Curcumin has a protective effect on radiation-induced cutaneous damage in mice, which is characterized by a downregulation of both inflammatory and fibrogenic cytokines in irradiated skin and muscle, particularly in the early phase after radiation. These results may provide the molecular basis for the application of curcumin in clinical radiation therapy.

Myofiber degeneration/regeneration is induced in the cachecticApcMin/+mouse

Cachexia is characterized as an inflammatory state induced by the cancer environment, which is accompanied by the loss of muscle and fat mass. Well-investigated mechanisms of cachexia include the suppression of myofiber protein synthesis and the induction of the protein degradation. However, it is not well characterized whether chronic inflammation during cachexia induces myofiber degeneration, which contributes to muscle mass loss and decreased functional capacity. The purpose of this study was to determine whether Apc(Min/+) mice, which demonstrate a chronic systemic inflammatory state due to an intestinal tumor burden, undergo cachexia and whether the myofibers exhibit signs of degeneration and/or regeneration. Six-month-old female Apc(Min/+) body weight decreased 21% compared with C57BL/6 mice and was not the result of blunted growth. Apc(Min/+) gastrocnemius muscle was reduced 45%, and soleus mean fiber cross-sectional area decreased 24% vs. C57BL/6 mice. Soleus muscle morphology demonstrated pathology of myofibers undergoing degeneration and/or regeneration. These data demonstrate that the Apc(Min/+) mouse becomes cachectic by 6 mo of age and that skeletal muscle degeneration and regeneration may be related to the muscle loss.

Nutritional status of cancer patients and its relationship to function in an inpatient rehabilitation setting

BACKGROUND

Malnutrition is associated with prolonged hospitalization, lower survival rate, and various medical complications. However, little is known about malnutrition and its relationship with the functional status. We undertook this retrospective study to examine whether or not malnutrition affects rehabilitation outcome in patients who had undergone cancer rehabilitation.

METHODS

We conducted a review of the charts of 30 consecutive cancer patients who had been admitted to the inpatient rehabilitation unit in a tertiary cancer center, from the beginning of March 2001 to the end of April 2001.

RESULTS

The patients' mean rehabilitation stay was 9 days and their mean age was 58 years (range 22-86 years). On rehabilitation admission, 15 of the patients (50%) had a below normal prealbumin (<18 mg/dl) level (95% confidence interval 31-69%), and on discharge 10 of the patients (33%) had a below normal prealbumin level (95% CI 17-54%). The serum prealbumin concentration level correlated with motor functional independence measure scores on admission. After inpatient rehabilitation, statistically significant gains in functional independence measure scores (P<0.0001) were obtained in patients with below normal admission prealbumin, as well as in those whose prealbumin levels were within the normal range; no statistically significant difference was found in functional gain between these two groups.

CONCLUSION

Our study showed that a large number of cancer rehabilitation patients had malnutrition. Nevertheless, functional gain was achieved in all patients after rehabilitation, whether or not malnutrition was present. We conclude that malnourished patients should still be considered candidates for rehabilitation.

Exhaustive physical exercise increases the number of colonic preneoplastic lesions in untrained rats treated with a chemical carcinogen

Aberrant crypt foci (ACF) have been used for early detection of factors that influence colorectal carcinogenesis in rats. It has been observed that exhaustive exercise increases free radical DNA oxidative damage and depresses immune function, events also related to the increased risk for cancer development. Fifteen days after a single exhaustive swimming bout in untrained rats treated with a colon carcinogen, we observed a statistically significant increased number of ACF when compared to the non-exercised group. Thus, we concluded that exhaustive exercise increased the susceptibility for colon cancer in rats. From our finding and literature data, we hypothesize that, similarly to the suggested relationship between exercise and infections, exercise could be protective against cancer or it could increase the risk for this disease depending on its type, dose and duration.

Exercise Restores Immune Cell Function in Energy-Restricted Rats

OBJECTIVE

To evaluate the effect of chronic moderate-intensity exercise upon the alterations of immune system cell function induced by energy restriction.

METHODS

Forty male Wistar rats were randomly assigned to the following groups: sedentary animals fed ad libitum (SF, N = 10) or submitted to energy restriction (SER, N = 10, receiving 50% of the mean amount of chow consumed by SF); and trained animals fed ad libitum (TF, N = 10) or submitted to energy restriction (TER, N = 10), who exercised on a treadmill (at 60-65%VO(2max) 5 d.wk(-1) for 10 wk(-1), after 30 d under the restriction protocol. The incorporation of [2-(14)C]-thymidine by lymphocytes obtained from the spleen and mesenteric lymph nodes, plasma glucose and glutamine concentration, and cytokine production by cells cultivated in the presence of glutamine were measured in all groups, 24 h after the last exercise session. Two-way ANOVA and Tukey's posttest were employed for the statistical analysis.

RESULTS

Training induced an increase in the proliferative response and in the production of gamma-interferon and interleukin-1 (P < 0.05) in cells from the spleen and lymph nodes of SER, in which these parameters were diminished when compared with SF (P < 0.05). SER spleen and lymph node cells produced more TNF (26 and 42%, respectively) and IL-2 (49 and 42%, respectively) than SF. The Th1-like diversion of the immune response observed in SER persisted after training. Partial recovery of the decreased SER plasma glutamine concentration and muscle glutamine synthase mRNA was observed.

CONCLUSIONS

Training induced the recovery of the proliferative capacity of lymphocytes from SER, probably due to the partial restoration of plasma glutamine levels, but did not interfere with the diversion towards a Th1-type immune response induced by food restriction.

Rehabilitation and quality-of-life issues in patients with extremity soft tissue sarcoma

The current standard of care for soft tissue sarcoma (STS) is limb salvage surgery and adjuvant radiotherapy, with long-term survival rates of approximately 70%. However, the extensive surgical resection and subsequent reconstruction result in 50% of survivors living with chronic disability. Rehabilitation aims to optimize functional independence and quality of life, and is routinely offered to patients undergoing surgical treatment for STS. Unfortunately, there is a dearth of research related to rehabilitation in this area. We propose a model for assessing disability, for designing treatment interventions and for evaluating rehabilitative outcomes in STS. The World Health Organization's (WHO) international classification of functioning, disability, and health (ICF) is divided into three domains: 1) impairments (related to body structure and function), 2) activity limitations (related to usual self-care activities/activities of daily living), and 3) participation restrictions (related to social roles). A literature review of STS rehabilitation reveals that most studies have focused on disability assessment, with few papers describing or evaluating rehabilitation interventions commonly employed in STS. Clinicians are forced to extrapolate findings from other patient populations in order to evaluate the effectiveness of specific rehabilitation strategies (ie, those used for particular sequelae of STS, such as lymphedema or impaired exercise tolerance). There is strongest support for complex decongestive physiotherapy (targeting lymphedema) and aerobic exercise interventions (aimed at alleviating cancer-related fatigue and psychosocial sequelae). The most poorly researched topic is rehabilitation for genitourinary disability (both incontinence and sexual dysfunction). Most studies related to oncologic rehabilitation are restricted to the impairment level (eg, affecting range of motion, muscle strength) of the ICF, with only a small minority addressing activity limitations (eg, affecting activities of daily living) experienced by patients. A consideration of participation restrictions (eg, fulfillment of vocational roles) is almost wholly absent from the literature. Yet social role reintegration is of fundamental importance to patients. Further research is required in these two domains. The ICF provides a comprehensive framework for future research into rehabilitation interventions for STS.

Physical fitness training: outcomes for adult oncology patients

Physical activity and exercise participation are important considerations in the study and management of acute and long-term care for cancer patients. Although excessive rest and lack of physical activity are related to diminished physical fitness, reduced functional status, impaired cognition, and diminished quality of life, exercise prescription is not a standard treatment support for patients or survivors of cancer. In this retrospective study, it was hypothesized that routine participation in exercise could improve physical fitness for adults recently completing months of cancer treatment. Forty-five cancer patients were able to make considerable fitness gains over an 8-week period. A fitness program coordinated by an exercise physiologist, certified trainers, and an advanced practice cancer nurse was an effective method of organizing referral, monitoring individual patient concerns, and avoiding unnecessary risks.

Cancer-related fatigue: can exercise physiology assist oncologists?

Most patients with cancer experience fatigue, a severe activity-limiting symptom with a multifactorial origin. To avoid cancer-related fatigue, patients are frequently advised to seek periods of rest and to reduce their amount of physical activity. This advice is reminiscent of that formerly given to patients with heart disease. However, such recommendations can paradoxically compound symptoms of fatigue, since sedentary habits induce muscle catabolism and thus cause a further decrease in functional capacity. By contrast, there is scientific evidence that an exercise programme of low to moderate intensity can substantially reduce cancer-related fatigue and improve the quality of life of these patients. Current knowledge, combined with findings soon to be published, could launch new opportunities for patients with cancer. In this new century, exercise physiology could soon prove to be very useful for oncologists.