OBJECTIVETo examine the expression of Ezrin in human salivary gland adenoid cystic carcinoma and investigate the effects of Ezrin gene silence on cell proliferation, apoptosis and invasion of adenoid cystic carcinoma (ACC)-M.

METHODSThe expression of Ezrin was detected by immunohistochemistry in normal salivary gland tissue (n=15), pleomorphic adenoma (n=40) and salivary gland adenoid cystic carcinoma (n=43). The Ezrin Stealth RNAi Duplex, containing Stealth RNAi Negative Control Duplex were constructed and transfected into ACC-M cells by Lipofectamine 2000. The expression levels of Ezrin were detected by RT-PCR and immunohistochemistry. The cell cycle and apoptosis rate were analyzed by flow cytometry (FCM). The cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) and cell invasion by Transwell test.

RESULTSThe positive rate of Ezrin expression in ACC was significantly higher than that in normal salivary gland tissue and pleomorphic adenoma (P<0.05). After transfection of Ezrin Stealth RNAi Duplex, the mRNA and protein expression of Ezrin were down-regulated, the cell proliferation activity was inhibited, the G0-G1 Phase cells were increased, and the apoptosis rate of Ezrin Stealth RNAi Duplex group was higher than that in control groups and cell invasion ability was decreased.

CONCLUSIONSOver expression of Ezrin in human salivary gland adenoid cystic carcinoma may promote genesis, development and metastasis of tumors. Ezrin Stealth RNAi Duplex could efficiently down-regulate the expression of Ezrin gene, and partly inhibited proliferation of ACC-M cells, induce apoptosis and decrease invasion ability of these cells in vitro.