Expression and function mechanism of microRNA-126 in esophageal squamous cell carcinoma

Abstract

Objective To investigated microRNA(miR)-126 expression and its potential targets in esophageal squamous cell carcinoma(ESCC). Methods The expression level of miR-126 was detected in cancerous and paired paracancerous tissues from 75 patients with ESCC, association between miR-126 level and clinicopathologic characteristics were analysised.Target analysis of miR-126 was predicted using online tools.The effect of miR-126 expression on target proteins was assessed through up/ down miR-126 level in ESCC cell lines. Results The relative expression of miR-126 in ESCC tissues was 0. 28±0. 32 and 0. 45±0. 47 in normal tissues(P< 0. 01).Low level of miR-126 was associated with tumor differentiation, lymph nodes metastasis, tumor in-depth, and TNM stages (P< 0. 05).Insulin receptor substrate-1(IRS-1) was over-expressed and associated with cell differentiation(P< 0. 01).In ESCC cell line Eca9706, Eca109 and TE-1, miR-126 mimics down-regulated the expression of IRS-1 protein(0. 785±0. 337, 1. 873±0. 684, 1. 938±1. 081) compared with non-treated control(1. 188±0. 336, 2. 756±1. 097,3. 028±0. 789, P< 0. 01), whereas miR-126 inhibitors lead to the opposite results(2. 543±0. 610, 5. 182±1. 897, 5. 940±0. 997, P<0. 01). Conclusion This study revealed that miR-126 is low-expressed in ESCC and acts as a tumor suppressor in the carcinogenesis of ESCC.IRS-1 was downstream targets of miR-126 in ESCC. Key words: Esophageal squamous cell carcinoma; MicroRNA-126; Insulin receptor substrate-1