Epidemiologic evidence in humans suggests a role for
selenium in reducing
cancer incidence and mortality. The aim of the present study was that to assess the ability of
selenium dioxide (SeO2) to enhance the lymphocyte progression through the cell cycle in patients with advanced (stage IV)
cancer. Ten patients (mean age 51.9 years, range: 32-74; M/F ratio: 3/7) with
tumors at different sites were included in the study. The addition into culture of SeO2 1.5 microM enhanced significantly the progression into S phase of PBMCs isolated from
cancer patients, whilst no significant effect was observed on PBMCs isolated from controls. ROS levels were significantly higher, whereas GPx activity was significantly lower in
cancer patients than controls. Serum levels of
IL-6 and
TNFalpha were significantly higher in
cancer patients than controls. Our results show the ability of
selenium to induce a progression of PBMCs from
cancer patients into the cell cycle, which is an essential prerequisite for the physiological functioning of the immune system and thus positively influence the immune status of advanced
cancer patients. The mechanism of action of
selenium could be to downregulate the production and release of proinflammatory
cytokines, which have a role in
cancer progression and particularly in the onset of
cachexia.