MiR-30 suppresses lung cancer cell 95D epithelial mesenchymal transition and invasion through targeted regulating Snail.

Objective: As an important factor regulating the epithelial mesenchymal transition (EMT) Snail is associated with lung cancer. Bioinformatics analysis showed that microRNA-30a (miR-30a) may target the 3'-UTR of Snail mRNA. It was exhibited that miR-30a down-regulation was related to tumor size, TNM stage, and poor prognosis of non-small cell lung cancer (NSCLC) patients, which suggests that miR-30a might participate in NSCLC attack. This study aims to explore the role of miR-30a and Snail in NSCLC invasion and metastasis. Patients and

Methods: NSCLC tumor and para-carcinoma tissues were collected from 46 patients to evaluate the miR-30a and Snail expressions. The targeted relationship between miR-30a and Snail was verified by using dual-luciferase reporter assay. 95D cells were cultured in vitro and transfected with miR-30a mimic or small interfere RNA targeting Snail (si-Snail). The expression of miR-30a, Snail, EMT-related factors, malignant growth, invasion, and apoptosis, were compared.

Results: Snail was significantly up-regulated, while miR-30a was significantly reduced in NSCLC tissue. MiR-30a suppressed Snail expression by targeting the 3'-URT of Snail mRNA. 95D cells exhibited significantly higher Snail, N-cadherin, and vimentin levels, while lower miR-30a, E-cadherin, and occludin expressions were compared with 95C cells. 95D cells presented stronger malignant growth and invasive ability, whereas lower background apoptosis than 95C. MiR-30a mimic and/or si-Snail transfection significantly enhanced E-cadherin and occludin expression, while significantly declined N-cadherin and vimentin levels, thus weakening malignant growth and invasion and increasing cell apoptosis.

Conclusions: Snail up-regulated, while miR-30a declined in NSCLC tissue. MiR-30a may suppress Snail expression, restrain EMT, and inhibit lung cancer cell invasion.