Effect of physical activity on human prostate cancer cells proliferation: involvement of oxidative stress?
Résumé
Key words: physical activity, oxidative stress, prostate cancer. Prostate cancer (PC) constitutes a growing health concern. It represents the second cause of death by cancer in France. Among the various origins of PC, sedentary behaviour is an important risk factor and a decrease of PC prevalence is associated with exercise. Physical activity could prevent some cancers, especially breast and colon cancers. However, studies concerning its effects in PC progression are today conflicting and conclusions are difficult to reach. A recent study has suggested that golf enhances the life expectancy about 5 years (adjusted by age, sex and socioeconomic status of subjects). This physical activity which registered 410377 members in France mainly corresponds to a walking sport but it attracts more players. Golf could be suitable for men with low grade PC. The objectives of this study are (1) to determine if golfers serum has an effect on the in vitro proliferation of human PC cells and (2) to identify the involved molecular mechanisms. Oxidative stress (OS) phenotypes leading to an imbalance of redox status in favor of oxidant could play a role in the prostate tumorigenesis. The regular physical activity known to increase antioxidant defenses could reduce the evolution of the PC through OS-dependent signaling pathways. Sedentary or golfer subjects serum is incubated with androgen-dependent LNCaP cells. Proliferation, cell death as well as molecular mechanisms are studied, mainly those dependent of OS. We demonstrate that golfers' serum inhibits the LNCaP cells proliferation without inducing cell death. This inhibition of proliferation doesnt depend on oxidative stress since no difference appears between the redox status of sedentarys and golfers serum. Golf could reduce the proliferation of PC cells in vitro but the preliminary results require further investigations.