NUKLEONIKA 2005, 50(Supplement 2):S17-S20
Emil Lisiak1, Mirosław Dziekiewicz2, Victor Meineke3, Marek Bilski1, Marek K. Janiak1
1 Military Institute of Hygiene and Epidemiology,
Department of Radiobiology and Radiation Protection,
4 Kozielska Str., 01-163 Warsaw, Poland
2 Military Institute of Health Services,
Department of General, Oncological and Vascular Surgery,
128 Szaserów Str., 00-909 Warsaw, Poland
3 Bundeswehr Institute of Radiobiology,
11 Neuherbergstrasse, 80937 Munich, Germany
Recently, significant attention has been paid to the possibility of thwarting cancer progression by
inhibition of neoangiogenesis (formation of new blood vessels) in growing tumors. Although general
mechanisms of angiogenesis have been elucidated, virtually nothing is known about the effects of low
doses of ionizing radiation on pro-angiogenic properties of endothelial cells. In the present study,
we evaluated the effects of a low (0.2 Gy), intermediate (1 Gy), and high (4 Gy) doses of X-rays on
a few angiogenesis-related parameters of isolated murine endothelial cells. We show here that 24 to
48 hours after irradiation with 0.2 Gy the cell proliferation was inhibited to a similar extent as after
the exposure to 1 Gy. Also, adhesion of the 0.2 Gy-irradiated cells to both gelatin and Matrigel®
was inhibited 24 hours post-exposure, whereas irradiation with 1 or 4 Gy resulted in the increased
adhesion of the cells to these substrata. Similar effects were observed during the “wound” migration
assay. Finally, 24 hours after exposure of the cells to 0.2 Gy of X-rays, the surface expression of the
b3 integrin subunit was down-regulated, whereas irradiations
with 1 and 4 Gy of X-rays resulted in the significantly elevated expression of this subunit. These
results indicate that proliferating endothelial cells are sensitive in vitro to relatively low
doses of ionizing radiation and that the effects of a low dose are opposite to those observed
after irradiations with 1 and 4 Gy of X-rays.