Effect of miR-524-5p on Epithelial-mesenchymal Transition in Esophageal Cancer Cells by Regulating HEG1 Expression

Objective To investigate the mechanism and the effect of miR-524-5p regulating HEG1 expression on the proliferation and epithelial-mesenchymal transition of esophageal cancer cells.

Methods The expression levels of miR-524-5p and HEG1 mRNA in esophageal cancer cells and normal esophageal epithelial cells were detected by qRT-PCR. KYSE30 cells were divided into miR-524-5p mimic group, miR-524-5p NC group, miR-524-5p mimic+pcDNA3.1 group, and miR-524-5p mimic+pcDNA3.1-HEG1 group. Non-transfected cells were set as the normal control group (group Control). CCK-8 method was applied to detect the proliferation ability of KYSE30 cells. Western blot analysis was conducted to detect the expression of proteins related to EMT, invasion, and migration and the HEG1 protein. Scratch and Transwell assays were applied to detect the migration and invasion abilities of KYSE30 cells. A dual-luciferase reporter gene was used to examine the targeting relationship between miR-524-5p and HEG1.

Results miR-524-5p was lowly expressed in four esophageal cancer cell lines, namely, TE-1, KYSE30, KYSE150, and NEC (P < 0.05). KYSE30 cells with the lowest expression level were selected for subsequent experiments. HEG1 mRNA was highly expressed in four esophageal cancer cell lines (P < 0.05). The GEPIA database showed that HEG1 was highly expressed in esophageal cancer tumor tissues (P < 0.05). KYSE30 cells in the miR-524-5p mimic group had lower proliferation ability, colony formation number, mesenchymal marker protein expression, and migration and invasion abilities and upregulated epithelial marker protein E-cadherin level than cells in the miR-524-5p NC group (P < 0.05). The miR-524-5p mimic+pcDNA3.1-HEG1 group significantly reversed the inhibitory effect of overexpression of miR-524-5p on the proliferation, epithelial–mesenchymal transformation, invasion, and metastasis of KYSE30 cells (P < 0.05). The luciferase activity of cells in the miR-524-5p mimic and WT-HEG1 co-transfection groups was lower than that in the miR-524-5p NC and WT-HEG1 co-transfection groups (P < 0.05).

Conclusion miR-524-5p is lowly expressed in EC cells and tissues. The overexpression of miR-524-5p can negatively regulate the expression of HEG1 in esophageal cancer cell line (KYSE30 cells) and reduce the proliferation, EMT process, and invasion and migration abilities of KYSE30 cells.