Mechanisms of Combined Effect of Beta-Lapachone and X-irradiation against Cancer Cells

초록

Beta(B)-Lapachone, a quinone from Lapacho tree, is an experimental anti-cancer drug, which is able to induce clonogenic and apoptotic cell death in various cancer cells in vitro and in vivo The mechanisms by which B-lap kills cancer cells has been contraversial, but recent reports have suggested that B-lap is converted to hydroquinone form receiving two electron from NADH or NAD(P)H mediated by NAD(P)H:quinine oxidoreductase (NQO1). The reduced B-lap is unstable and it is reoxidized to original B-lap in the presence of oxygen resulting in futile cycling between the quinine and hydroquinone forms, thereby severely reducing NADH and NAD(P)H level and activating calpain-like proteases.