Biological effect of irradiation on adhesion molecules in human colon cancer cells in vitro.

ABSTRACT

BACKGROUND: Carbohydrate antigens, such as sialyl Lewis(a) antigen (s-Le(a)) and sialyl Lewis(x) antigen (s-Le(x)), play an important role in cancer metastasis in vitro and in vivo. Currently, preoperative radiotherapy is used to prevent local recurrence of rectal cancer. We investigated the effects of X-ray irradiation on the carbohydrate antigens s-Le(a) and s-Le(x) in vitro. MATERIALS AND METHODS: The cell surface expressions of s-Le(a) and s-Le(x) were determined by flow cytometric analysis at 24 hours after X-ray irradiation of 4 human cancer cell lines. s-Le(a) and s-Le(x) functions were quantitated using a monolayer cell adhesion assay with human umbilical vein endothelial cells (HUVECs). RESULTS: The cell surface expressions of s-Le(a) and s-Le(x) decreased at 24 hours after irradiation. s-Le(a) adhesion to HUVECs monolayers similarly decreased at 24 hours after irradiation. CONCLUSION: These results may indicate a role for X-ray irradiation in the reduction of liver metastasis in patients with colon cancer.