MicroRNA-100 promotes migration and invasion through mammalian target of rapamycin in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the predominant histologic subtype of esophageal cancer and is characterized by a high mortality rate and geographic differences in incidence. microRNAs (miRNAs) are small, non-coding RNAs that play important roles in the regulation of genes associated with cancer development and progression. In the present study, we demonstrated that microRNA-100 (miR-100) demonstrated markedly lower expression in the ESCC tissues as validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Furthermore, we found that the downregulation of miR-100 was significantly correlated with the status of lymph node metastasis in the 34 ESCC patients. Next, we investigated the role and mechanism of miR-100 in ESCC cells and found that miR-100 modulated the migration and invasion but not the apoptosis and proliferation of ESCC cells in vitro. We further demonstrated that miR-100 directly targeted the mTOR 3'UTR and repressed the expression of mTOR, a tumor-related gene. Similarly, miR-100 has been reported as a tumor suppressor by controlling cell migration and invasion, as it can target mTOR genes. These results provide insight into the potential mechanisms of miR-100 in the pathogenesis of ESCC.