Radiation-induced cell cycle arrests in Ehrlich ascites carcinoma cells in vivo.

Radiation-induced progression delay in G(1)/S, S and G(2)/M phases of p53 wild-type Ehrlich ascites carcinoma (EAC) cells growing in vivo was investigated by DNA flow cytometry. Different behavior patterns of EAC cells at the time after irradiation with low (2, 4, 6, 8 Gy) and high (10, 15, 20 Gy) doses were evaluated. While EAC cells showed a small progression delay in S phase and a dose-dependent block in G(2)/M phase after the irradiation with low doses, a clear additional block in G(1)/S phase was observed after irradiation with high doses. An assessment of the damage response and repair networks at the time after irradiation might have important implication for the development of cancer management and treatment.