The natural flavolignan deoxypodophyllotoxin (DPPT) inhibits tubulin polymerization and induces cell cycle arrest at G2/M, followed by apoptosis. However, the precise mechanism of DPPT action is currently unknown. Here, we investigated the mechanism by which DPPT treatment of HeLa cervical carcinoma cells induces cell cycle arrest and apoptosis. We show that DPPT treatment inhibits cell viability in a dose-dependent manner and that this reduction in cell viability results from cell cycle arrest at...