Abstract
We studied the cell cycle progression and the induction of cyclinB1 and p21 in cultured human fibroblasts after irradiation with heavy ion beams at HIMAC of NIRS. Asynchronous human normal fibroblasts (NB1RGB) in monolayer were irradiated with X-rays, carbon ion beam (75 keV/um), Si ion beam (250 keV/um), and Fe ions (200-440 keV/um) at room temperature. Cell cycle distribution and the protein induction were measured by flow cytometory. After irradiation, both G1 and G2 block were observed independently on ions. From 30 to 50 percent of NB1RGB cells have accumulated at G2/M phase. Percentage of cell number at G2/M phase increased with dose up to 2 Gy. CyclinB1 was expressed only in G2/M phase cells. The percentage of cells in which cyclin B1 was expressed increased with incubation time after irradiation up to 8 h. No increment of cyclin B1 expression was observed from 2 Gy to 10 Gy. P21 was expressed both in G1 and G2/M cells after 3 h and longer incubation after irradiation. [J Radiat Res 44:407 (2003)]
