Esophageal cancer is one of the most common cancers worldwide. It is critical to find early diagnostic biomarkers for esophageal cancer. MicroRNAs (miRNAs) play important regulatory roles in occurrence and development of esophageal cancer, which has the diagnostic and prognostic values. The aim of the study was to evaluate the potential diagnostic value of the novel miRNA. The novel miRNA was predicted using miRDeep2 software and validated by quantitative reverse transcription PCR (qRT-PCR) and the TA-cloning sequencing of the PCR products. The expression of the novel miRNA in esophageal cancer tissues and adjacent tissues was also analyzed by qRT-PCR. The EdU staining and transwell method were used to detect the capacity of cell proliferation, migration, and invasion. Besides, the target gene CTNNA2 of novel-miR-4885 was verified via qRT-PCR, western blot, luciferase reporter assay, and RNA immunoprecipitation. We identified the novel-miR-4885, the expression level was confirmed by qRT-PCR in the esophageal cancer cells. The result of TA-cloning sequencing was consistent with the prediction and the pre-miRNA had a standard hairpin stem-loop structure. In addition, the expression of novel-miR-4885 was upregulated in esophageal cancer tissue compared with that in adjacent tissue (p < 0.05). Further, the assays showed that overexpression novel-miR-4885 could improve the cell proliferation, migration, and invasion with an average fold change of 1.19, 1.59, and 2.34, respectively. Novel-miR-4885 can bind to 3' untranslated region of CTNNA2 to reduce cell adhesion and promote epithelial-mesenchymal transition in esophageal cancer cell. The expression of N-cadherin, β-catenin, Vimentin, and α-smooth muscle actin was upregulated, while that of E-cadherin and ZO-1 proteins was downregulated through western blot. Novel miRNA present in esophageal cancer cells was validated, supplementing the miRNA database. Meantime, the possible functional mechanisms were explored, and the results showed that the novel miRNA may serve as potential biomarker for the diagnosis of esophageal cancer.
Keywords: EMT; biomarker; esophageal cancer; novel miRNA.