The effect of radiation on the expression of intercellular adhesion molecule-1 of human adenocarcinoma cells

Purpose: To investigate the changes in antigenic expression of intercellular adhesion molecule-1 (ICAM-1) caused by ionizing radiation of cultured human adenocarcinoma cells. Methods and Materials: Human colonic BM314 and gastric MKN45 adenocarcinoma cells were irradiated to investigate the expression of ICAM-1 on the cell membrane and in the supernatant. In addition, the ICAM-1 gene expression (mRNA) was analyzed using a ICAM-1 cDNA as a probe. Results: The expression of ICAM-1 on the membrane was found to increase by irradiation. This effect was also observed in the supernatant. In addition, the irradiated cell population showed slight, but clear increases in ICAM-1 mRNA expression. Conclusions: These results show that the enhancement of expression of ICAM-1 by radiation takes place at the ICAM-1 gene expression (mRNA) level. The results suggest that the low dose radiation may be useful for accumulating LFA-1 positive cytotoxic T lymphocytes (CTL) at the local tumor tissue, by which tumor cells may be attacked