Regulation of tumor cell apoptotic sensitivity during the cell cycle (Review)

Understanding how current chemotherapeutic modalities induce apoptosis is c ritical to designing better anticancer agents. This review is concerned wit h how pharmacological agents induce tumor cell apoptosis in a cell cycle-de pendant manner. Recent experiments demonstrate that expression of several a poptotic regulatory proteins (such as Bcl-2, Bar, p53, and Survivin) are di fferentially regulated according to the phases of the cell cycle. This cell cycle-dependent regulation in turn contributes to increased drug sensitivi ty in different phases of the cell cycle. It is therefore likely that the c ell cycle-dependent expression of cell death proteins plays a role in regul ating chemosensitivity and apoptotic commitment of human tumor cells.