The role of exercise in immune responses to cancer from prevention to treatment

According to many preclinical, clinical and epidemiological studies, exercise could be used as a miracle drug in the prevention, treatment, rehabilitation, and late survivorship of different type of cancer. Theevaluation of pooled data from twelve European and US cohort studies showed that physical activity (leisure-time) was correlated with lower risk of breast, endometrial, colon, and 10 additional cancers.Several mechanisms had been proposed for this preventive effect. Physical activity could regulate imbalance metabolic pathways that could initiate cell transformation to mutagenic status. Exercise mayadjust the level of sex hormones (estrogens and androgens), metabolic growth hormones (insulin, glucose, leptin), as well as protein and cytokines which are involved in insulin metabolism and chronicinflammation. Other antitumor postulate roles of exercise are potentiating the immune system and reducing the angiogenic factors, inflammatory cytokines, stress hormones and oxidative stress. Exercisemay increase the cell trafficking and function of the innate immune system (natural killer [NK] cells, neutrophils, and monocytes,) and, to a lesser extent, of the adaptive immune system (B and T cells).During exercise, there is an increase in serum epinephrine and also myokines which are released by contracted muscle. These mediators may activate NK cells and increase their mobilization into thebloodstream as well as recruitment and infiltration in solid tumors. Exercise could help immune cells to follow abnormal transformed cells, which had been escaping from immune control by decreasingimmunogenicity. In addition, exercise could eliminate the effect of chronic stress as an important factor in tumor growth and metastasis. In chronic stress, an elevated level of glucocorticoids suppresseschemotherapy-induced cancer cell apoptosis and activation of β-adrenergic receptor signaling pathways stimulated angiogenesis, cell migration, and invasion. Conclusion: Sufficient physical activity couldsuppress tumor initiation and progression by regulation of tumor microenvironment and biological pathways that affect tumorigenesis. Therefore, exercise could be suggested as a safe immunotherapystrategy for cancer prevention and treatment

کلیدواژه ها:

Cancer Prevention ، Cancer Risks ، Lifestyle and Cancer ، Nutrition and Cancer ، Cancer Treatment and Management