The Effect of Carbon Ion Beam Irradiation for Hypoxia-Mediated Invasion of Glioblastoma

抄録

Glioblastoma is one of the most fatal malignant tumors because of its invasiveness and radioresistance. Unfortunately photon irradiation and hypoxic condition are reported to enhance cancer cells' aggressiveness respectively. The purpose of this study is to clarify the effect of carbon ion beam on invasive potential of glioblastoma cells. Relative Biological Effectiveness of A172 cells measured by the dose for 1% survival fraction was 2.22. X-irradiation and hypoxic condition promoted invasion and migration of A172 and T98G cells respectively, while carbon ion beam suppressed both the two capabilities enhanced by hypoxia. GTP-RhoA (active form) was increased by 0.5 Gy of X-irradiation. On the other hand RhoA was inactivated by 1 and 4 Gy of carbon ion beam. Carbon ion beam irradiation suppressed glioblastoma cells' invasion and migration via inactivation of RhoA. Furthermore carbon ion beam also inhibited these abilities enhanced by hypoxia.