Abstract: OBJECTIVE:To study the effects of all_trans retinoic acid(atRA) on the proliferation, apoptosis and cytoskeleton microfilaments of esophageal carcinoma cells EC109. METHODS： After exposed to atRA for 48 h, the morphological structure of EC109 cell were examined under phase contrast microscope, and MTT assay was applied to evaluate cell growth. The apoptic cells were stained with Annexin V_FITC and detected by flow cytometry. The cytoskeleton microfilaments were studied with fluorescence microscope after staining with FITC_labelled phalloidin. RESULTS： The proliferation ratios of 0.1, 1, 2, 5 μmol/L atRA_treated group were 98.29％, 93.15％, 89.92％ and 81.03％, respectively, with significant difference between 5 μmol/L atRA_treated group and control group (P<0.05). Cells in early stage of apoptosis of treated groups were 0.65％, 0.94％, 0.93％, 0.94％, respectively, but without significant difference when compared with control group. The cytoskeleton was re_arranged and lost the typical filamentous structure after EC109 cells were exposed to 2 μmol/L and 5 μmol/L atRA for 24 h. CONCLUSION： Present study did not show atRA induced apoptosis of esophageal carcinoma cell line EC109, while atRA at high concentration demonstrated a potential to inhibit the growth of esophageal carcinoma cells. It is possible that atRA regulates the proliferation and growth of esophageal carcinoma cells through cytoskeleton changes.

Key words: retinoic acid, esophageal carcinoma cell, proliferation, cytoskeleton