Long non-coding RNA myocardial infarction associated transcript promotes epithelial-mesenchymal transition and is an independent risk factor for poor prognosis of tongue squamous cell carcinoma

Background: Long non-coding RNA myocardial infarction associated transcript (MIAT) has been suspected to be associated with poor prognosis in several malignancies. This study aims to investigate the association between MIAT expression levels and prognosis of tongue squamous cell carcinoma (TSCC).

Materials and methods: Expressions of MIAT in TSCC specimens, corresponding adjacent non-neoplastic tongue tissues, and serums collected from 116 TSCC patients were detected by Quantitative Real-Time PCR. Then, these patients were followed up for 12 months after discharge. MIAT was suppressed and upregulated in TSCC cells, and then cell invasion and epithelial-mesenchymal transition (EMT) markers were analyzed.

Results: Myocardial infarction associated transcript expression level in TSCC specimen was upregulated compared to adjacent non-neoplastic tongue tissue and had a significant positive association with its level in serum. MIAT levels in both TSCC specimen and serum were correlated with cervical lymph node metastasis and histological grading of TSCC patients. Results of survival analysis showed that high expression levels of MIAT in both TSCC tissues and serums indicated higher mortality and shorter survival time of TSCC patients. Receiver operating characteristic curve analysis showed that there was no significant difference between MIAT in TSCC specimen and serum to differentiate death and non-death of TSCC patients. In vitro study showed that MIAT could induce invasion of TSCC cells by regulating expressions of EMT markers through activation of Wnt/β-catenin signaling pathway.

Conclusion: Upregulated MIAT promoted EMT of TSCC cells through activation of Wnt/β-catenin signaling pathway and indicated a poor prognosis of TSCC, which may provide us a non-invasive approach to evaluate the prognosis of TSCC.