Ezrin, actin and cytoskeleton in apoptosis of esophageal epithelial cells induced by arsenic trioxide.

Ezrin is a key protein in membrane-cytoskeleton interaction. Expression of ezrin in actin-rich cell surfaces may play a role in the modulation of cell shape and adhesion. The aim of this study was to detect ezrin, actin and cytoskeleton and to explore their relationship in the apoptosis of esophageal epithelial cells (SHEE) induced by arsenic trioxide (As2O3). The SHEE is an immortalized human fetal esophageal epithelial cell line, and the cells were treated by administering 5, 10 and 20 micromol of As2O3. the proliferation and apoptosis of SHEE cells were examined by flow cytometry with propidium iodide staining. Ezrin expression was detected by immunocytochemistry and Western blotting. Actin filament was stained by FITC-labeled phalloidin and detected quantitatively by fluorescent microscopy. Cell morphology and microfilaments were examined by electron microscopy. The results revealed that As2O3 induced an inhibition of proliferation and the promotion of apoptosis in SHEE cells. The ezrin, actin and cytoskeleton were decreased after As2O3 treatment and the cellular morphology of apoptosis developed. Our results suggested that the morphological changes of arsenic-induced apoptosis of human esophageal epithelial cells were initiated by ezrin and actin-cytoskeletal aberrance.