Radiation-induced ICAM-1 expression via TGF-1 pathway on human umbilical vein endothelial cells; Comparison between X-ray and carbon-ion beam irradiation

Kiyohara, Hiroki*; Ishizaki, Yasuki*; Suzuki, Yoshiyuki*; Kato, Hiroyuki*; Hamada, Nobuyuki*; Ono, Tatsuya*; Takahashi, Takeo*; Kobayashi, Yasuhiko; Nakano, Takashi*

Radiation-induced intercellular adhesion molecule-1 (ICAM-1) expression on endothelial cells was investigated with the use of an inhibitor of transforming growth factor-beta1 (TGF-1) receptor kinase (SB431542) and the effects of X-ray and carbon-ion beam were compared. Expression of ICAM-1 was increased by X-ray and carbon-ion beam irradiation and decreased significantly with SB431542 after both irradiations. The expression of ICAM-1 by 2 Gy of carbon-ion beam irradiation was 6.7 fold higher than that of non-irradiated cells, while 5 Gy of X-ray irradiation increased the expression of ICAM-1 by 2.5 fold. According to ICAM-1 expression, the effect of carbon-ion beam irradiation was about 2.2, 4.4 and 5.0 times greater than that of the same doses of X-ray irradiation (1, 2 and 5 Gy, respectively). The present results suggested that radiation-induced ICAM-1 expression on human umbilical vein endothelial cells (HUVE cells) was, at least partially, regulated by TGF-1. Carbon-ion beam induced significantly higher ICAM-1 expression than X-ray.