Published online Jun 21, 2017. doi: 10.3748/wjg.v23.i23.4243
Peer-review started: January 4, 2017
First decision: February 9, 2017
Revised: March 14, 2017
Accepted: March 31, 2017
Article in press: March 31, 2017
Published online: June 21, 2017
Processing time: 169 Days and 23.8 Hours
To explore the effect of miR-382 on esophageal squamous cell carcinoma (ESCC) in vitro and its possible molecular mechanism.
Eca109 cells derived from human ESCC and Het-1A cells derived from human normal esophageal epithelium were used. Lentivirus-mediated miR-382 was overexpressed in Eca109 cells. The effect of miR-382 on cell proliferation was evaluated by MTT and colony formation assay. For cell cycle analysis, cells were fixed and stained for 30 min with propidium iodide (PI) staining buffer containing 10 mg/mL PI and 100 mg/mL RNase A, and analyzed by BD FACSCalibur™ flow cytometer. For cell apoptosis assay, cells were stained with an Annexin V-FITC/PI Apoptosis Detection Kit according to the manufacturer’s instructions and analyzed by a dual-laser flow cytometer. Cell invasion and migration abilities were determined through use of transwell chambers, non-coated or pre-coated with matrigel. Levels of proteins related to cell growth and migration were examined by western blotting.
Endogenous miR-382 was down-regulated in Eca109 cells compared with Het-1A. Introduction of miR-382 not only significantly inhibited proliferation and colony formation, but also arrested cell cycle at the G2/M phase, as well as promoted apoptosis and autophagy in Eca109 cells. Migration, invasion and epithelial-mesenchymal transition of Eca109 cells were suppressed by overexpressing miR-382. Western blotting results showed that miR-382 inhibited the phosphorylation of mTOR and 4E-BP1.
miR-382 functions as a tumor suppressor against ESCC development and metastasis, and could be considered as a potential drug source for the treatment of ESCC patients.
Core tip: Our previous study revealed that miR-382 was significantly down-regulated in esophageal squamous cell carcinoma (ESCC) patients with short-term motility, implying that miR-382 may display antitumor function in ESCC development and metastasis. We present here that miR-382 functions as a tumor suppressor by inhibiting proliferation, migration, invasion and epithelial-mesenchymal transition, in addition to inducing cell cycle arrest, apoptosis and autophagy in Eca109 cells. Inhibitory influence on protein translation mediated by mTOR/4E-BP1 signaling might be involved in the antitumor activity of miR-382 against ESCC. Thus, manipulation of miR-382 level can be a potentially therapeutic intervention for ESCC.