Interleukin-18 upregulates FasL protein expression and its function in colon cancer cell line.

Objective To investigate the modulation of FasL protein in colon cancer cells by interleukin 18 (IL 18) and it's effect on tumor cells counterattacking T lymphocytes. Methods By using Western blotting assay, FasL protein expression was examined in human colon cancer cell line SW620. The ratio of apoptosis of lymphocytes induced by tumor cells was studied by flow cytometry analysis. Results 10 μg/L and 100 μg/L IL 18 upregulated FasL protein expression in SW620 cell line, reaching the peak in 18 and 36 hours respectively, and returned to initial levels in 72 hours. The ratio of apoptosis of Jurkat cells induced by tumor cells increased in accordance with the upregulation of FasL protein. Conclusions IL 18 upregulates FasL protein expression in colon cancer cell line and enhances the ability of cancer cells to counterattack T lymphocytes.