放射線治療におけるバイスタンダー効果の生物学的意義
Significance of Radiation-induced Bystander Effects in Radiation Therapy

Masao Suzuki
2014 Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics  
Since 1994, a Phase I/II clinical study and radiotherapy have carried out using carbon-ion beams produced with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences. Now we constructed the new treatment facility for the advanced carbon-ion therapy at HI-MAC applying a 3D fast spot scanning system with pencil beams. In the field of fundamental biological studies for high-LET heavy ions, there are some reports regarding bystander effects after exposure
more » ... o alpha particles derived from 238 Pu or He-ion microbeams. However, only limited sets of studies have examined bystander effects after exposure to different ion species heavier than helium, such as carbon ions. We have been investigating bystander cellular responses in both normal human and human tumor cells irradiated with the HIMAC carbon ions. Bystander cell-killing effect was observed in the cells harboring wild-type P53 gene, but not in the P53-mutated cells. Moreover, observed bystander effect was suppressed by treating with a specific inhibitor of gap-junction mediated cell-cell communication. There is clear evidence that the carbon-ion irradiation enables the enhanced cell killing in cells with wild-type P53 gene via gap-junction mediated bystander effect.
doi:10.11323/jjmp.34.2_70 fatcat:hls73qgngzbslnm2572bsphg54