New Insights about the Potential Application of the Association of Vitamins C (Sodium Ascorbate) and K3 (Menadione) as Auxiliary Therapy in Cancer Treatment

Cancer is characterized by cell cycle deregulation, progressive loss of cell differentiation and uncontrolled growth. Since cancer cells are particularly sensitive to oxidative stress, we took advantage of this poor antioxidant status to develop an experimental approach to selectively expose cancer cells to an oxidant insult induced by the association of vitamins C and K3 (CK3). The results we obtained reinforce the major role of oxidative stress as the main mechanism involved in cell killing by CK3, either under in vivo or in vitro conditions. Such an antitumor activity has been attributed to redox cycling of the vitamins and the possible generation of peroxides and other reactive oxygen species. We report herein, on the ability of the association of ascorbate with several quinone derivatives (having different redox potentials) to cause cell death. Finally, we determined that cell death by CK3 is not related to the activation of MAP kinases pathways.