Expression of interleukin 1β converting enzyme in 5-FU induced apoptosis in esophageal carcinoma cells

AIM To study the role of interleukin 1 beta converting enzyme (ICE) in antitumor drug-induced apoptosis in tumor cells. METHODS Morphological changes in human esophageal carcinoma Eca-109 cells after treated with 5-fluorouracil (5-FU) were observed under light and electron microscope. Expression of ICE in the tumor cells exposed to 5-FU was examined by the immunocytochemical method. RESULTS The cells treated with 5-FU displayed disappearance of nucleoli, chromatin gathering under nuclear envelope, karyorrhexis, budding and the formation of apoptotic bodies. The expression of ICE was negative in control cells, and 5-FU could induce the ICE expression in Eca-109 cells undergoing apoptosis. The number and the staining intensity of positive cells increased with the extension of action time. CONCLUSION ij-FU may induce apoptosis in human esophageal carcinoma Eca-109 cells; ICE gene may be involved in the regulation of 5-FU-induced apoptosis; and ICE protein may mediate apoptosis induced by 5-FU.