Influence of Exercise on Inflammation in Cancer: Direct Effect or Innocent Bystander?

The role of exercise in obesity-related cancers: Current evidence and biological mechanisms

Cancer ranks among the five leading causes of death in almost all countries and has important repercussions for individual and public health, the healthcare system, and society in general. Obesity increases the incidence of many types of cancer, but growing evidence suggests that physical activity may decrease risk for developing a variety of obesity-related cancer types, and, in some cases, may improve cancer prognosis and mortality rates. This review summarizes recent evidence on the effect of physical activity on obesity-related cancer prevention and survival. For some cancers, including breast, colorectal, and endometrial cancer, there is strong evidence for a preventative effect of exercise, but for many others, including gallbladder and kidney cancer, and multiple myeloma, evidence is inconsistent or largely lacking. Though many potential mechanisms have been proposed to explain the onco-protective effect of exercise, including improved insulin sensitivity, alterations in sex hormone availability, improved immune function and inflammation, myokine secretion, and modulation of intracellular signaling at the level of AMP kinase, the exact mechanism(s) of action within each cancer subtype remains poorly defined. Overall, a deeper understanding of how exercise can help against cancer and of the exercise parameters that can be altered to optimize exercise prescription is necessary and should be the subject of future investigation.

Sequestration of Inflammation in Parkinson's Disease via Stem Cell Therapy

Parkinson’s disease is the second most common neurodegenerative disease. Insidious and progressive, this disorder is secondary to the gradual loss of dopaminergic signaling and worsening neuroinflammation, affecting patients’ motor capabilities. Gold standard treatment includes exogenous dopamine therapy in the form of levodopa–carbidopa, or surgical intervention with a deep brain stimulator to the subcortical basal ganglia. Unfortunately, these therapies may ironically exacerbate the already pro-inflammatory environment. An alternative approach may involve cell-based therapies. Cell-based therapies, whether endogenous or exogenous, often have anti-inflammatory properties. Alternative strategies, such as exercise and diet modifications, also appear to play a significant role in facilitating endogenous and exogenous stem cells to induce an anti-inflammatory response, and thus are of unique interest to neuroinflammatory conditions including Parkinson’s disease. Treating patients with current gold standard therapeutics and adding adjuvant stem cell therapy, alongside the aforementioned lifestyle modifications, may ideally sequester inflammation and thus halt neurodegeneration.

Exercise Counteracts the Deleterious Effects of Cancer Cachexia

Simple Summary

This review provides an overview of the effects of exercise training on the major mechanisms related to cancer cachexia (CC). The review also discusses how cancer comorbidities can influence the ability of patients/animals with cancer to perform exercise training and what precautions should be taken when they exercise. The contribution of other factors, such as exercise modality and biological sex, to exercise effectiveness in ameliorating CC are also elaborated in the final sections. We provide meticulous evidence for how advantageous exercise training can be in patients/animals with CC at molecular and cellular levels. Finally, we emphasise what factors should be considered to optimise and personalise an exercise training program in CC.

Abstract

Cancer cachexia (CC) is a multifactorial syndrome characterised by unintentional loss of body weight and muscle mass in patients with cancer. The major hallmarks associated with CC development and progression include imbalanced protein turnover, inflammatory signalling, mitochondrial dysfunction and satellite cell dysregulation. So far, there is no effective treatment to counteract muscle wasting in patients with CC. Exercise training has been proposed as a potential therapeutic approach for CC. This review provides an overview of the effects of exercise training in CC-related mechanisms as well as how factors such as cancer comorbidities, exercise modality and biological sex can influence exercise effectiveness in CC. Evidence in mice and humans suggests exercise training combats all of the hallmarks of CC. Several exercise modalities induce beneficial adaptations in patients/animals with CC, but concurrent resistance and endurance training is considered the optimal type of exercise. In the case of cancer patients presenting comorbidities, exercise training should be performed only under specific guidelines and precautions to avoid adverse effects. Observational comparison of studies in CC using different biological sex shows exercise-induced adaptations are similar between male and female patients/animals with cancer, but further studies are needed to confirm this.

High Intensity Interval Training Leads to Similar Inflammatory Activation as Seen With Traditional Training in Chronic Heart Failure

BACKGROUND

Inflammatory activation has been associated with the severity and progression of chronic heart failure (CHF). Although cardiac rehabilitation is an important therapy, acute bouts of exercise may lead to increases in pro-inflammatory cytokines with exercise intensity mediating these changes.

OBJECTIVE

To evaluate the acute inflammatory response in patients living with CHF during a randomized trial following Steady State (SS) or High Intensity Interval (HIIT) training.

METHODS

Patients living with CHF (n = 14) were stratified (for body mass and aerobic power) and randomized into SS and HIIT cycle exercise. The HIIT exercise training involved 2 min work:recovery phases at 90:40% heart rate reserve. The SS exercise training involved continuous exercise at 65% of heart rate reserve (matched total work). Acute inflammatory markers were evaluated (via ELISA) at baseline, immediately following the bout, and at 6, 24, and 48 h post-exercise.

RESULTS

There was limited differences in the changes in inflammatory biomarkers across time between the HIIT and SS groups. Both groups experienced a significant (p < 0.05) change in Interleukin-6 immediately post-exercise.

CONCLUSIONS

A single bout of HIIT or SS does not result in excessive inflammatory activation in CHF patients. Acute HIIT and SS result in similar changes in inflammatory markers. These findings have important implications for exercise training and rehabilitation programs in persons living with CHF.

Effects of 8-week noncontinuous aerobic exercise on the levels of CCL2, CCL5, and their respective receptors in female BALB/C mice suffering from breast cancer

Background:

Recently, the importance of chemokines and their receptors in carcinogenesis and the protective role of aerobic exercise in primary cancer development and progression is highlighted. Based on the facts that endurance exercise may result in hypoxia condition, and in addition, the effect of exercise therapy on the levels of CCL2, CCR2, and their related receptors in breast cancer (BC) model has not been investigated so far, therefore we aimed to evaluate the effect of eight-week noncontinuous aerobic training on the levels of CCL2, CCL5, and their related receptors; CCR2 and CCR5 in female BALB/C mice with BC.

Methods:

Thirty-two BALB/C mice (4–5 weeks old) were randomly divided to four 8-member groups of control and experimental. The experimental group received 8 weeks of noncontinuous aerobic exercises (AEs) while the control group did not receive any exercises during these 8 weeks. After last of experiment, 5 ml of blood was taken from each rat's lower inferior vein. The plasma levels of CCL2 and CCL5 were measured by ELISA and CCR2 and CCR5 by western blot. Tumor volume also measured in each step. Data were analyzed using the ANOVA test and the SPSS v. 0.24 Software.

Results:

After 8 weeks of participation in noncontinuous AEs, a statistically significant decrease was made between the control and experimental groups in terms of CCL2, CCL5, and CCR2 levels, as well as tumor volume. However, there was no significant difference between groups in terms of CCR5 level.

Conclusions:

It can be concluded that the 8 weeks of noncontinuous AEs did not result in CCR5 reduction while resulting in a statistically significant decrease in CCL2, CCL5, CCR2, and tumor volume.

Spontaneous Physical Activity in Obese Condition Favours Antitumour Immunity Leading to Decreased Tumour Growth in a Syngeneic Mouse Model of Carcinogenesis

Simple Summary

With aging, a deterioration of the immune system, termed immunosenescence, leads to a loss of innate and adaptive immunity in terms of number of cells and functionality. This results in an imbalance between pro- and anti-tumour immune response. The aim of the study was to explore the impact of physical activity on the tissue environment in a murine model of breast carcinogenesis. In this model, spontaneous physical activity slows tumour growth by decreasing low-grade inflammation and promotes antitumour immunity.

Abstract

Our goal was to evaluate the effect of spontaneous physical activity on tumour immunity during aging. Elderly (n = 10/group, 33 weeks) ovariectomized C57BL/6J mice fed a hyperlipidic diet were housed in standard (SE) or enriched (EE) environments. After 4 weeks, orthotopic implantation of syngeneic mammary cancer EO771 cells was performed to explore the immune phenotyping in the immune organs and the tumours, as well as the cytokines in the tumour and the plasma. EE lowered circulating myostatin, IL-6 and slowed down tumour growth. Spleen and inguinal lymph node weights reduced in relation to SE. Within the tumours, EE induced a lower content of lymphoid cells with a decrease in Th2, Treg and MDCS; and, conversely, a greater quantity of Tc and TAMs. While no change in tumour NKs cells occurred, granzyme A and B expression increased as did that of perforin 1. Spontaneous physical activity in obese conditions slowed tumour growth by decreasing low-grade inflammation, modulating immune recruitment and efficacy within the tumour.

What is the gut feeling telling us about physical activity in colorectal carcinogenesis?

In the last decades, more efforts are focused on the prevention and treatment of malignant diseases, given the increase in all cancers incidence A lifestyle change, including healthy eating habits and regular physical activity, has significantly impacted colorectal cancer prevention. The effect of dose-dependent physical activity on mortality and recurrence rates of colorectal carcinoma has been unequivocally demonstrated in observational studies. However, clear recommendations are not available on the frequency, duration, and intensity of exercise in patients with colorectal cancer due to the lack of evidence in randomized clinical trials. Regarding pathophysiological mechanisms, the most plausible explanation appears to be the influence of physical activity on reducing chronic inflammation and insulin resistance with a consequent positive effect on insulin growth factor 1 signaling pathways.

Exercise Reduces the Resumption of Tumor Growth and Proteolytic Pathways in the Skeletal Muscle of Mice Following Chemotherapy

Simple Summary

Doxorubicin is a chemotherapeutic agent that contributes to muscle wasting. Based on the evidence that many cancer variants are associated with cachexia and that cancer patients are usually treated with chemotherapeutic agents, it is important to determine strategies to mitigate muscle atrophy. Muscle loss is a poor prognosis during cancer treatment, and exercise has emerged as a potential strategy utilized in this context. Once an ongoing regimen of chemotherapeutic treatment is not always possible, our results demonstrated that continuity of endurance exercise is a potential strategy that can be adopted when chemotherapy needs to be interrupted, minimizing the resumption of tumor growth and avoiding muscle loss.

Abstract

The pathogenesis of muscle atrophy plays a central role in cancer cachexia, and chemotherapy contributes to this condition. Therefore, the present study aimed to evaluate the effects of endurance exercise on time-dependent muscle atrophy caused by doxorubicin. For this, C57 BL/6 mice were subcutaneously inoculated with Lewis lung carcinoma cells (LLC group). One week after the tumor establishment, a group of these animals initiated the doxorubicin chemotherapy alone (LLC + DOX group) or combined with endurance exercise (LLC + DOX + EXER group). One group of animals was euthanized after the chemotherapy cycle, whereas the remaining animals were euthanized one week after the last administration of doxorubicin. The practice of exercise combined with chemotherapy showed beneficial effects such as a decrease in tumor growth rate after chemotherapy interruption and amelioration of premature death due to doxorubicin toxicity. Moreover, the protein degradation levels in mice undergoing exercise returned to basal levels after chemotherapy; in contrast, the mice treated with doxorubicin alone experienced an increase in the mRNA expression levels of the proteolytic pathways in gastrocnemius muscle (Trim63, Fbxo32, Myostatin, FoxO). Collectively, our results suggest that endurance exercise could be utilized during and after chemotherapy for mitigating muscle atrophy promoted by doxorubicin and avoid the resumption of tumor growth.

Effect of exercise on colorectal cancer prevention and treatment

In recent years, because of improved cancer screening, detection and treatment modalities, a rapid increase in the population of colorectal and other cancer survivors has been observed. The increasing population has justified the requirement of preventive strategies such as lifestyle modifications with regard to obesity, physical activity, diet and smoking. Physical activity may prevent approximately 15% of the colon cancers. Furthermore, several observational studies have demonstrated the efficacy and dose-dependent and anti-cancer effects of exercise on decreasing the mortality and risk of recurrence before and after the colorectal cancer (CRC) diagnosis. However, the required exercise dose, type and intensity are yet unclear. The results of randomised prospective studies are expected to determine the optimal amount, type and intensity of exercise and formulate the most appropriate exercise plan and guidelines, according to the requirements and comorbidities of the patients. In addition, recent studies have focused on the molecular and genetic mechanisms underlying the effect of physical activity on disease outcomes and recurrence rates. This review aimed to investigate the effects of physical activity and the biological basis of these effects in preventing the risk and recurrence of CRC and decreasing the hazards of cancer and cancer treatment.

Physical activity initiated by employer induces improvements in a novel set of biomarkers of inflammation: an 8-week follow-up study

Purpose

We investigated the level of pro- and anti-inflammatory biomarkers before and after 8 weeks of unsupervised physical activity (PA) initiated by employer.

Methods

During autumn 2014, background data, blood samples and self-reported exercise level were collected from 76 men and 41 women in a Norwegian road maintenance company. Monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), leptin, adiponectin, p-selectin and CD40 ligand (CD40L) were analyzed. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot V}{{\rm{O}}_{{\rm{2max}}}}$$\end{document}V˙O2max was measured in a subgroup of 50 subjects.

Results

With reference point of exercise ≤1 time/week, we found that participants who exercised 2–3 times/week had higher \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot V}{{\rm{O}}_{{\rm{2max}}}}$$\end{document}V˙O2max values (5.6 mL kg⁻¹ min⁻¹; 95% CI [1.3, 9.9]). MCP-1 was lower in those who exercised ≥ 4 times/week (−81.98 pg/ml [−142.9, −21.0]). IL-6 and p-selectin levels were lower in females who exercised ≥4 times/week (−1.04 pg/ml [−2.04, −0.03] and −13.75 ng/ml [−24.03, −3.48]). Leptin was lower in participants who exercised 2–3 times/week (−0.39 µg/ml ln [−0.68, −0.09]) and ≥4 times/week (−0.69 µg/ml ln [−1.10, −0.28]). During follow-up, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\dot V}{{\rm{O}}_{{\rm{2max}}}}$$\end{document}V˙O2max increased (2.9 mL kg⁻¹ min⁻¹ [1.5, 4.3]), while p-selectin and CD40L decreased (−2.33 ng/ml [−3.78, −0.87] and 718.14 ng/ml [−1368, −68]). MCP-1 levels decreased among men (−32.70 pg/ml [−51.21, −14.19]). A joint analysis of all biomarkers (inversed adiponectin) showed that those who exercised ≥4 times/week at baseline had lower total levels of biomarkers and that total biomarker levels decreased during follow-up.

Conclusions

Exercising several times a week was associated with less inflammation compared to exercising once a week or less. During the 8-week follow-up, total levels of biomarkers of inflammation improved.

Electronic supplementary material

The online version of this article (doi:10.1007/s00421-016-3533-5) contains supplementary material, which is available to authorized users.

Voluntary exercise improves murine dermal connective tissue status in high-fat diet-induced obesity

Obesity is a risk factor for several cardiovascular and metabolic diseases. Its influence on the skin is less obvious, yet certain negative effects of adipose tissue inflammation on the dermis have been suggested. Excess weight is closely associated with sedentary behavior, so any increase in physical activity is considered beneficial against obesity. To investigate the effects of obesity and physical exercise on the skin, we established a mouse model in which mice were kept either on a high-fat diet or received standard chow. After the two groups achieved a significant weight difference, physical exercise was introduced to both. Animals were given the opportunity to perform voluntary exercise for 40 min daily in a hamster wheel for a period of 8 weeks. We evaluated the status of the dermis at the beginning and at the end of the exercise period by in vivo nonlinear microscopy. Obese mice kept on high-fat diet lost weight steadily after they started to exercise. In the high-fat diet group, we could detect significantly larger adipocytes and a thicker layer of subcutaneous tissue; both changes started to normalize after exercise. Nonlinear microscopy revealed an impaired collagen structure in obese mice that improved considerably after physical activity was introduced. With the ability to detect damage on collagen structure, we set out to address the question whether this process is reversible. With the use of a novel imaging method, we were able to show the reversibility of connective tissue deterioration as a benefit of physical exercise.

Optitrain: a randomised controlled exercise trial for women with breast cancer undergoing chemotherapy

BACKGROUND

Women with breast cancer undergoing chemotherapy suffer from a range of detrimental disease and treatment related side-effects. Exercise has shown to be able to counter some of these side-effects and improve physical function as well as quality of life. The primary aim of the study is to investigate and compare the effects of two different exercise regimens on the primary outcome cancer-related fatigue and the secondary outcomes muscle strength, function and structure, cardiovascular fitness, systemic inflammation, skeletal muscle gene activity, health related quality of life, pain, disease and treatment-related symptoms in women with breast cancer receiving chemotherapy. The second aim is to examine if any effects are sustained 1, 2, and 5 years following the completion of the intervention and to monitor return to work, recurrence and survival. The third aim of the study is to examine the effect of attendance and adherence rates on the effects of the exercise programme.

METHODS

This study is a randomised controlled trial including 240 women with breast cancer receiving chemotherapy in Stockholm, Sweden. The participants are randomly allocated to either: group 1: Aerobic training, group 2: Combined resistance and aerobic training, or group 3: usual care (control group). During the 5-year follow-up period, participants in the exercise groups will receive a physical activity prescription. Measurements for endpoints will take place at baseline, after 16 weeks (end of intervention) as well as after 1, 2 and 5 years.

DISCUSSION

This randomised controlled trial will generate substantial information regarding the effects of different types of exercise on the health of patients with breast cancer undergoing chemotherapy. We expect that dissemination of the knowledge gained from this study will contribute to developing effective long term strategies to improve the physical and psychosocial health of breast cancer survivors.

TRIAL REGISTRATION

OptiTrain - Optimal Training Women with Breast Cancer (OptiTrain), NCT02522260 ; Registration: June 9, 2015, Last updated version Feb 29, 2016. Retrospectively registered.