Exercise training to increase tumour natural killer-cell infiltration in men with localised prostate cancer: a randomised controlled trial.

OBJECTIVES: To explore the effects of preoperative high-intensity interval training (HIIT) compared to usual care on tumour natural killer (NK)-cell infiltration in men with localised prostate cancer (PCa), as NK-cell infiltration has been proposed as one of the key mechanisms whereby exercise can modulate human tumours. PATIENTS AND METHODS: A total of 30 patients with localised PCa undergoing radical prostatectomy (RP) were randomised (2:1) to either preoperative aerobic HIIT four-times weekly (EX; n = 20) or usual care (CON; n = 10) from time of inclusion until scheduled surgery. Tumour NK-cell infiltration was assessed by immunohistochemistry (CD56+ ) in diagnostic core needle biopsies and corresponding prostatic tissue from the RP. Changes in cardiorespiratory fitness, body composition, blood biochemistry, and health-related quality of life were also evaluated. RESULTS: The change in tumour NK-cell infiltration did not differ between the EX and CON groups (between-group difference: -0.09 cells/mm2 , 95% confidence interval [CI] -1.85 to 1.66; P = 0.913) in the intention-to-treat analysis. The total number of exercise sessions varied considerably from four to 30 sessions. The per-protocol analysis showed a significant increase in tumour NK-cell infiltration of 1.60 cells/mm2 (95% CI 0.59 to 2.62; P = 0.004) in the EX group. Further, the total number of training sessions was positively correlated with the change in NK-cell infiltration (r = 0.526, P = 0.021), peak oxygen uptake (r = 0.514, P = 0.035) and peak power output (r = 0.506, P = 0.038). CONCLUSION: Preoperative HIIT did not result in between-group differences in tumour NK-cell infiltration. Per-protocol and exploratory analyses demonstrate an enhanced NK-cell infiltration in PCa. Future studies are needed to test the capability of exercise to increase tumour immune cell infiltration.

Effects of acute exercise training on tumor outcomes in men with localized prostate cancer: A randomized controlled trial.

Postdiagnosis physical activity is associated with improved cancer outcomes, but biological mechanisms mediating anticancer effects remain unclear. Recent findings suggest that physiological adaptations to acute exercise comprise potential anticancer effects, but these remain poorly explored in clinical settings. The objective of this study was to explore the effects of a single exercise bout on tumor oxygenation and immune cell infiltration in patients with prostate cancer. Thirty patients with localized prostate cancer were randomized (2:1) to either one high-intensity interval training bout or no exercise on the day before radical prostatectomy. Immunohistochemical analyses were performed on prostatic tissue from surgery and assessed for tumor hypoxia, natural killer (NK) cell infiltration, and microvessel density (MVD). Acute systemic response in blood lymphocytes, epinephrine, norepinephrine, IL-6, tumor necrosis factor, cortisol, lactate, and glucose was also evaluated. We did not find between-group differences in tumor hypoxia (Mann-Whitney U test, U = 83.5, p = 0.604) or NK cell infiltration (U = 77.0, p = 0.328). Also, no significant correlation was found between MVD and tumor hypoxia or NK cell infiltration. One exercise bout is likely insufficient to modulate tumor hypoxia or NK cell infiltration. Future studies may elucidate if an accumulation of several exercise bouts can impact these outcomes (NCT03675529, www.clinicaltrials.gov).

Exercise suppresses tumor growth independent of high fat food intake and associated immune dysfunction.

Epidemiological data suggest that exercise training protects from cancer independent of BMI. Here, we aimed to elucidate mechanisms involved in voluntary wheel running-dependent control of tumor growth across chow and high-fat diets. Access to running wheels decreased tumor growth in B16F10 tumor-bearing on chow (- 50%) or high-fat diets (- 75%, p < 0.001), however, tumor growth was augmented in high-fat fed mice (+ 53%, p < 0.001). Tumor growth correlated with serum glucose (p < 0.01), leptin (p < 0.01), and ghrelin levels (p < 0.01), but not with serum insulin levels. Voluntary wheel running increased immune recognition of tumors as determined by microarray analysis and gene expression analysis of markers of macrophages, NK and T cells, but the induction of markers of macrophages and NK cells was attenuated with high-fat feeding. Moreover, we found that the regulator of innate immunity, ZBP1, was induced by wheel running, attenuated by high-fat feeding and associated with innate immune recognition in the B16F10 tumors. We observed no effects of ZBP1 on cell cycle arrest, or exercise-regulated necrosis in the tumors of running mice. Taken together, our data support epidemiological findings showing that exercise suppresses tumor growth independent of BMI, however, our data suggest that high-fat feeding attenuates exercise-mediated immune recognition of tumors.

Exercise training as prophylactic strategy in the management of neutropenia during chemotherapy.

Chemotherapy-induced immune-suppression is a common, but potential detrimental, adverse reaction in patients undergoing treatment for cancer and strategies with capacity to boost the immune cell populations are needed. Physical exercise training is a potent regulator of immune cell viability and function and may serve as a viable, non-pharmacological prophylactic strategy in addition to the current pharmacological management by, for example, granulocyte-colony stimulating factor (G-CSF). Here, we review the mechanistic evidence linking exercise training to haematopoietic function and subsequent possible amelioration of chemotherapy-related neutropenia. First, we briefly describe neutrophil regulation and management of neutropenia in cancer patients. Second, we summarize the effect of acute and chronic exercise training on neutrophils and their progenitors, and finally, we outline the current clinical evidence of exercise interventions in ongoing anti-cancer treatment in regard to neutropenia incidence, treatment tolerance and related outcomes. LINKED ARTICLES: This article is part of a themed issue on New avenues in cancer prevention and treatment (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.12/issuetoc.

Voluntary wheel running can lead to modulation of immune checkpoint molecule expression.

BACKGROUND: Exercise and physical activity (PA) are associated with reduced tumor growth and enhanced intra-tumoral immune cell infiltration in mice. We aimed to investigate the role of PA achieved by voluntary wheel running in promoting the immunogenic profile across several murine tumor models, and to explore the potential of checkpoint blockade and PA in the form of voluntary wheel running as combination therapy. MATERIAL AND METHODS: The experiments were performed with C57BL/6 mice bearing subcutaneous tumors while having access to running wheels in their cages, where key immunoregulatory molecules expressed in the tumor tissue were measured by qPCR. Furthermore, we tested the hypothesis that wheel running combined with PD-L1 -or PD-1 inhibitor treatment could lead to an additive effect on tumor growth in mice bearing B16 melanoma tumors. RESULTS: Wheel running increased immune checkpoint expression (PD-1, PD-L1, PD-L2, CD28, B7.1 and B7.2) in B16 tumor-bearing mice, while induction of only PD-L2 was found in E0771 breast cancer and Lewis Lung Cancer. In studies combining voluntary wheel running with PD-1 -and PD-L1 inhibitors we found significant effects of wheel running on attenuating B16 melanoma tumor growth, in line with previous studies. We did, however, not find an additive effect of combining either of the two immunotherapeutic treatments with access to running wheels. CONCLUSION: B16 tumors displayed upregulated expression of immune regulatory molecules and decreased tumor growth in response to PA. However, combining PA with PD-1 or PD-L1 blockade did not lead to a further augmented inhibition of tumor growth.

Exercise-Mediated Lowering of Glutamine Availability Suppresses Tumor Growth and Attenuates Muscle Wasting.

Glutamine is a central nutrient for many cancers, contributing to the generation of building blocks and energy-promoting signaling necessary for neoplastic proliferation. In this study, we hypothesized that lowering systemic glutamine levels by exercise may starve tumors, thereby contributing to the inhibitory effect of exercise on tumor growth. We demonstrate that limiting glutamine availability, either pharmacologically or physiologically by voluntary wheel running, significantly attenuated the growth of two syngeneic murine tumor models of breast cancer and lung cancer, respectively, and decreased markers of atrophic signaling in muscles from tumor-bearing mice. In continuation, wheel running completely abolished tumor-induced loss of weight and lean body mass, independently of the effect of wheel running on tumor growth. Moreover, wheel running abolished tumor-induced upregulation of muscular glutamine transporters and myostatin signaling. In conclusion, our data suggest that voluntary wheel running preserves muscle mass by counteracting muscular glutamine release and tumor-induced atrophic signaling.

[Exercise training as preoperative optimisation in patients with cancer].

This review summarises the current knowledge of exercise training, which is increasingly used to rehabilitate patients with cancer after anti-cancer treatment, aiming to manage acute and long-term side effects and physical limitations. However, exercise training may also play a critical role in the early preoperative management of patients with cancer. In this period, preoperative exercise training may ensure, that patients reach the curative tumour resection by preventing tumour progression, reducing complications to neoadjuvant treatment and lessening physical deterioration, all leading to improved surgical outcome and enhanced long-term survival. †) Pernille Højman died 6 April 2019, after she had written a major part of the script.

Interval Walking Improves Glycemic Control and Body Composition After Cancer Treatment: A Randomized Controlled Trial.

CONTEXT: Patients with colorectal cancer have increased risk of metabolic diseases including diabetes. Exercise training may counteract metabolic dysregulation, but the impact of exercise training on glycemic control, including postprandial glycemia, has never been explored in patients with colorectal cancer. OBJECTIVE: To examine the effects of home-based interval walking on aerobic and metabolic fitness and quality of life in patients with colorectal cancer. DESIGN: Randomized controlled trial. SETTING: Clinical research center. PARTICIPANTS: Thirty-nine sedentary (<150 minutes moderate-intensity exercise per week) patients with stage I to III colorectal cancer who had completed primary treatment. INTERVENTION: Home-based interval walking 150 min/wk or usual care for 12 weeks. MAIN OUTCOME MEASURES: Changes from baseline to week 12 in maximum oxygen uptake (VO2peak) by cardiopulmonary exercise test, glycemic control by oral glucose tolerance test (OGTT), body composition by dual-energy x-ray absorptiometry scan, blood biochemistry, and quality of life. RESULTS: Compared with control, interval walking had no effect on VO2peak [mean between-group difference: -0.32 mL O2 · kg-1 · min-1 (-2.09 to 1.45); P = 0.721] but significantly improved postprandial glycemic control with lower glucose OGTT area under the curve [-126 mM · min (-219 to -33); P = 0.009], 2-hour glucose concentration [-1.1 mM (-2.2 to 0.0); P = 0.056], and improved Matsuda index [1.94 (0.34; 3.54); P = 0.01]. Also, interval walking counteracted an increase in fat mass in the control group [-1.47 kg (-2.74 to -0.19); P = 0.025]. CONCLUSION: A home-based interval-walking program led to substantial improvements in postprandial glycemic control and counteracted fat gain in posttreatment patients with colorectal cancer, possibly providing an effective strategy for prevention of secondary metabolic diseases.

IL-6 release from muscles during exercise is stimulated by lactate-dependent protease activity.

IL-6 is secreted from muscles to the circulation during high-intensity and long-duration exercise, where muscle-derived IL-6 works as an energy sensor to increase release of energy substrates from liver and adipose tissues. We investigated the mechanism involved in the exercise-mediated surge in IL-6 during exercise. Using interval-based cycling in healthy young men, swimming exercise in mice, and electrical stimulation of primary human muscle cells, we explored the role of lactate production in muscular IL-6 release during exercise. First, we observed a tight correlation between lactate production and IL-6 release during both strenuous bicycling and electrically stimulated muscle cell cultures. In mice, intramuscular injection of lactate mimicked the exercise-dependent release of IL-6, and pH buffering of lactate production during exercise attenuated IL-6 secretion. Next, we used in vivo bioimaging to demonstrate that intrinsic intramuscular proteases were activated in mice during swimming, and that blockade of protease activity blunted swimming-induced IL-6 release in mice. Last, intramuscular injection of the protease hyaluronidase resulted in dramatic increases in serum IL-6 in mice, and immunohistochemical analyses showed that intramuscular lactate and hyaluronidase injections led to release of IL-6-containing intramyocellular vesicles. We identified a pool of IL-6 located within vesicles of skeletal muscle fibers, which could be readily secreted upon protease activity. This protease-dependent release of IL-6 was initiated by lactate production, linking training intensity and lactate production to IL-6 release during strenuous exercise.

Exercise-mediated improvement of depression in patients with gastro-esophageal junction cancer is linked to kynurenine metabolism.

Background: Exercise may improve depression in cancer patients, yet the molecular mechanism behind this protection is poorly understood. Here, we aimed to explore the link between exercise and regulation of kynurenine (Kyn) metabolism and inflammation in patients with operable gastro-esophageal junction (GEJ) cancer patients, who improved significantly in depression score with exercise training. Material and Methods: Fifty GEJ cancer patients were allocated to 12 weeks of supervised training twice weekly including interval-based aerobic exercise and resistance training, or standard care. Depression score was evaluated by HADS, and blood samples and muscle biopsies were collected for determination of Kyn metabolism and inflammation across the intervention. Results: Depression scores decreased by -1.3 points in the exercise group (p < 0.01), whereas no changes were observed in the control group. Plasma 3-hydroxykynurenine (HK), a Kyn metabolite giving rise to other neurotoxic metabolites, increased by 48% (p <0.001) in the control group, while exercise training attenuated this accumulation. The production of HK is induced by inflammation, and while we observed no differences in systemic pro-inflammatory cytokines, exercise training ameliorated the treatment-induced intramuscular inflammation. Moreover, exercise has been suggested to convert Kyn to the neuroprotective metabolite, kynurenic acid (KA), but despite marked functional and muscular exercise-mediated adaptations, we did not observe any enhancement of KA production and related enzyme expression in the muscles of GEJ cancer patients. Conclusion: Exercise training reduced symptoms of depression in patients with GEJ cancer, and this effect was associated with an exercise-dependent attenuation of the inflammation-induced conversion of Kyn to neurotoxic metabolites.

Exercise Training in Cancer Control and Treatment.

Exercise training is playing an increasing role in cancer care, as accumulating evidence demonstrates that exercise may prevent cancer, control disease progression, interact with anti-cancer therapies, and improve physical functioning and psychosocial outcomes. In this overview article, we present the current state of the field of exercise oncology, which currently comprises of nearly 700 unique exercise intervention trials with more than 50,000 cancer patients. First, we summarize the range of these interventions with regard to diagnoses, clinical setting, timing, and type of intervention. Next, we provide a detailed discussion of the 292 trials, which have delivered structured exercise programs, outlining the impact of exercise training on cancer-specific, physiological, and psychosocial outcomes in the light of the challenges and physiological limitations cancer patients may experience. In summary, the safety and feasibility of exercise training is firmly established across the cancer continuum, and a wide range of beneficial effects on psychosocial and physiological outcomes are well documented. Many of these beneficial effects are linked to the general health-promoting properties of exercise. However, it is becoming increasing evident that exercise training can have direct effects on cancer and its treatment. This calls for future exercise oncology initiatives, which aim to target cancer-specific outcomes, and which are integrated into the concurrent cancer trajectory. Here, the field must bridge extensive knowledge of integrative exercise physiology with clinical oncology and cancer biology to provide a basis of individualized targeted approaches, which may place exercise training as an integrated component of standard cancer care. © 2019 American Physiological Society. Compr Physiol 9:165-205, 2019.

Effects of erythropoietin on body composition and fat-glucose metabolism in patients with affective disorders.

BACKGROUND: Erythropoietin (EPO) has been suggested to improve metabolism and also cognition, but human studies are scarce. This randomised controlled trial aimed to investigate whether EPO treatment influences body composition and fat and glycated haemoglobin (HbA1c) and fasting glucose, and whether these changes would be associated with previous observed cognitive benefits of EPO. METHOD: In total, 84 non-obese patients with treatment-resistant unipolar depression or bipolar disorder in remission were randomised to 8 weekly EPO (40,000 IU) or saline (NaCl 0.9%) infusions in a double-blind, parallel-group design. Patients underwent dual X-ray absorptiometry scans at baseline and week 14 (6 weeks after treatment completion). Cognitive measures were assessed and fasting levels of cholesterol, lipoprotein fractions, triacylglycerides, glucose and HbA1c were obtained at baseline, week 9 and follow-up week 14. RESULTS: In total, 79 patients had complete pre- and post-treatment data (EPO: N=40, saline: N=39). EPO had no cumulative effect on body composition and markers of fat metabolism. The EPO-treated group exhibited significantly lower HbA1c levels after 8 weeks treatment [F(1, 80)=8.51, p=0.005], however, 6 weeks after treatment termination a significantly higher fasting glucose levels [F(1, 79)=5.85, p=0.02] and HbA1c levels [F(1, 79)=5.85, p=0.02] were seen. The latter increase in HbA1c was further significantly correlated with a better cognitive outcome on verbal memory (r=0.25, p=0.03). CONCLUSION: Repeated EPO infusions had no cumulative effect on body composition in this cohort of patients with affective disorders, however, EPO modulated HbA1c and fasting glucose and this was associated with patients' improvement of verbal memory.

The "Interval Walking in Colorectal Cancer" (I-WALK-CRC) study: Design, methods and recruitment results of a randomized controlled feasibility trial.

BACKGROUND: Low physical activity level is associated with poor prognosis in patients with colorectal cancer (CRC). To increase physical activity, technology-based platforms are emerging and provide intriguing opportunities to prescribe and monitor active lifestyle interventions. The "Interval Walking in Colorectal Cancer"(I-WALK-CRC) study explores the feasibility and efficacy a home-based interval-walking intervention delivered by a smart-phone application in order to improve cardio-metabolic health profile among CRC survivors. The aim of the present report is to describe the design, methods and recruitment results of the I-WALK-CRC study.Methods/Results: The I-WALK-CRC study is a randomized controlled trial designed to evaluate the feasibility and efficacy of a home-based interval walking intervention compared to a waiting-list control group for physiological and patient-reported outcomes. Patients who had completed surgery for local stage disease and patients who had completed surgery and any adjuvant chemotherapy for locally advanced stage disease were eligible for inclusion. Between October 1st, 2015, and February 1st, 2017, 136 inquiries were recorded; 83 patients were eligible for enrollment, and 42 patients accepted participation. Age and employment status were associated with participation, as participants were significantly younger (60.5 vs 70.8 years, P < 0.001) and more likely to be working (OR 5.04; 95%CI 1.96-12.98, P < 0.001) than non-participants. CONCLUSION: In the present study, recruitment of CRC survivors was feasible but we aim to better the recruitment rate in future studies. Further, the study clearly favored younger participants. The I-WALK-CRC study will provide important information regarding feasibility and efficacy of a home-based walking exercise program in CRC survivors.

Sarcopenia and Postoperative Complication Risk in Gastrointestinal Surgical Oncology: A Meta-analysis.

OBJECTIVE: The aim of the study was to evaluate sarcopenia as a predictor of postoperative risk of major and total complications after surgery for gastrointestinal cancer. BACKGROUND: Sarcopenia is associated with poor survival in gastrointestinal cancer patients, but the role of sarcopenia as prognostic tool in surgical oncology has not been established, and no consensus exists regarding assessment and management of sarcopenic patients. METHODS: We performed a systematic search for citations in EMBASE, Web of Science, and PubMed from 2004 to January 31, 2017. Random effects meta-analyses were used to estimate the pooled risk ratio for postoperative complications by Clavien-Dindo grade (total complications: grade ≥2; major complications: grade ≥3) in patients with sarcopenia versus patients without sarcopenia. Stratified analyses were performed by sarcopenia criteria, cutoff level, assessment methods, study quality, cancer diagnosis, and "Enhanced Recovery After Surgery" care. RESULTS: Twenty-nine studies (n = 7176) were included with sarcopenia prevalence ranging between 12% and 78%. Preoperative incidence of sarcopenia was associated with increased risk of major complications (risk ratio 1.40; 95% confidence interval, 1.20-1.64; P < 0.001; I = 52%) and total complications (risk ratio 1.35; 95% confidence interval, 1.12-1.61; P = 0.001; I = 60%). Moderate heterogeneity was found for both meta-analyses. Subgroup analyses showed that sarcopenia remained a consistent risk factor across stratification by sarcopenia criteria, assessment methods, study quality, and diagnoses. CONCLUSIONS: Sarcopenia was associated with an increased risk of complications after gastrointestinal tumor resection, but lack of methodological consensus hampers the interpretation and clinical utilization of these findings. Combining assessment of muscle mass with measures of physical function may increase the prognostic value and accuracy in preoperative risk stratification.

Molecular Mechanisms Linking Exercise to Cancer Prevention and Treatment.

The benefits of exercise training for cancer patients are becoming increasingly evident. Physical exercise has been shown to reduce cancer incidence and inhibit tumor growth. Here we provide the status of the current molecular understanding of the effect of exercise on cancer. We propose that exercise has a role in controlling cancer progression through a direct effect on tumor-intrinsic factors, interplay with whole-body exercise effects, alleviation of cancer-related adverse events, and improvement of anti-cancer treatment efficacy. These findings have wide-ranging societal implications, as this understanding may lead to changes in cancer treatment strategies.

Progressive resistance training in head and neck cancer patients undergoing concomitant chemoradiotherapy.

Objectives: Patients with head and neck squamous cell carcinoma undergoing concomitant chemoradiotherapy (CCRT) frequently experience weight loss, especially loss of lean body mass (LBM), and reduced functional performance. This study investigated whether a 12-week hospital-based progressive resistance training (PRT) program during CCRT is feasible in the clinical setting before planning initiation of a larger randomized study which is the long-term goal. Study design: Prospective pilot study. Methods: Twelve patients receiving CCRT were planned to attend a 12-week PRT program. Primary endpoint was feasibility measured as attendance to training sessions. Secondary endpoints included changes in functional performance, muscle strength, and body composition measured by Dual-energy X-ray Absorptiometry (DXA) scans. Furthermore, sarcomeric protein content, pentose phosphate pathway (PPP) activity, and glycolysis were determined in muscle biopsies. Results: Twelve patients with p16 positive oropharyngeal cancer were enrolled. The primary endpoint was met with 9 of the 12 patients completing at least 25 of 36 planned training sessions. The mean attendance rate was 77%. Functional performance was maintained during the treatment period and increased during follow-up (p < 0.01). Strength was regained after an initial dip during treatment, paralleling responses in LBM and sarcomeric protein content. LBM began to increase immediately after treatment. The PPP was upregulated after the treatment period, whilst glycolysis remained unchanged. No adverse events were related to PRT and in questionnaires, patients emphasized the social and psychological benefits of attendance. Conclusion: Progressive resistance training is feasible and safe during CCRT for head and neck cancer, and is associated with high patient satisfaction. Level of Evidence: 2C.

Voluntary Wheel Running Reduces the Acute Inflammatory Response to Liver Carcinogen in a Sex-specific Manner.

Inflammation contributes to the development of cancer, yet acute inflammatory responses are also needed to eradicate tumorigenic cells and activate adaptive immune responses to combat cancer. Physical exercise has direct immunomodulatory effects, and in line with this, exercise has been demonstrated to inhibit tumor growth, including diethylnitrosamine-(DEN)-induced hepatocarcinoma. Having observed a sex-dependent development of DEN-induced hepatocarcinoma, we aimed to evaluate the effect of exercise and sex on the acute inflammatory response to DEN. Thus, we randomized male and female mice to cages with or without running wheels for 6 weeks, whereafter DEN was administered and the inflammatory response was evaluated for up to 96 hours. DEN administration caused marked acute inflammatory responses in female mice with weight loss, reduced food intake, release of liver enzymes, and increased systemic levels of IL6. Moreover, DEN caused increased hepatic expression of cytokines, immune cell markers, and components of the toll-like receptor signaling pathway. In male mice, DEN administration provoked similar physiologic effects with weight loss and reduced food intake, but less systemic and hepatic acute inflammation, which was associated with a higher baseline expression of the detoxifying enzyme glutathione S-transferase and lower expression of ERα in male mice. Voluntary wheel running attenuated systemic and hepatic inflammation, in particular in the female mice, and shifted the peak time of the inflammatory response. In conclusion, DEN elicited an acute inflammatory response in particular in female mice, and this response was attenuated by prior exercise. Cancer Prev Res; 10(12); 719-28. ©2017 AACR.

Exercise-Induced Catecholamines Activate the Hippo Tumor Suppressor Pathway to Reduce Risks of Breast Cancer Development.

Strong epidemiologic evidence documents the protective effect of physical activity on breast cancer risk, recurrence, and mortality, but the underlying mechanisms remain to be identified. Using human exercise-conditioned serum for breast cancer cell incubation studies and murine exercise interventions, we aimed to identify exercise factors and signaling pathways involved in the exercise-dependent suppression of breast cancer. Exercise-conditioned serum from both women with breast cancer (n = 20) and healthy women (n = 7) decreased MCF-7 (hormone-sensitive) and MDA-MB-231 (hormone-insensitive) breast cancer cell viability in vitro by 11% to 19% and reduced tumorigenesis by 50% when preincubated MCF-7 breast cancer cells were inoculated into NMRI-Foxn1nu mice. This exercise-mediated suppression of cell viability and tumor formation was completely blunted by blockade of ß-adrenergic signaling in MCF-7 cells, indicating that catecholamines were the responsible exercise factors. Both epinephrine (EPI) and norepinephrine (NE) could directly inhibit breast cancer cell viability, as well as tumor growth in vivo EPI and NE activate the tumor suppressor Hippo signaling pathway, and the suppressive effect of exercise-conditioned serum was found to be mediated through phosphorylation and cytoplasmic retention of YAP and reduced expression of downstream target genes, for example, ANKRD1 and CTGF. In parallel, tumor-bearing mice with access to running wheels showed reduced growth of MCF-7 (-36%, P < 0.05) and MDA-MB-231 (-66%, P < 0.01) tumors and, for the MCF-7 tumor, increased regulation of the Hippo signaling pathway. Taken together, our findings offer a mechanistic explanation for exercise-dependent suppression of breast cancer cell growth. Cancer Res; 77(18); 4894-904. ©2017 AACR.

Exercise protects from cancer through regulation of immune function and inflammation.

Exercise training has been extensively studied in cancer settings as part of prevention or rehabilitation strategies, yet emerging evidence suggests that exercise training can also directly affect tumor-specific outcomes. The underlying mechanisms for this exercise-dependent cancer protection are just starting to be elucidated. To this end, evasion of immune surveillance and tumor-associated inflammation are established as hallmarks of cancer, and exercise may target cancer incidence and progression through regulation of these mechanisms. Here, I review the role of exercise in protection from cancer through mobilization and activation of cytotoxic immune cells, restriction of inflammatory signaling pathways in myeloid immune cells, and regulation of acute and chronic systemic inflammatory responses. In conclusion, I propose that exercise has the potential to target tumor growth through regulation of immune and inflammatory functions, and exercise may be pursued as anticancer treatment through incorporation into standard oncological therapy to the benefit of the cancer patients.