Radiation and the G2 phase of the cell cycle

Exposure of mammalian cells to X rays results in prolongation of the cell cycle, including delays or arrests in G(1), S and G(2) phase. While G(1)-phase arrest occurs only in cells with wildtype p53 function, a G(2)-phase delay occurs in all cells regardless of p53 status. In this review, we summarize what is known about cell cycle progression through G(2) and M phase and discuss the experimental findings that implicate different mechanisms in the G(2)-phase delay. Finally, we consider the possibility that G(2)-phase arrest plays a role in cell survival after irradiation. (C) 1998 by Radiation Research Society.