miR-34b-5p suppresses the epithelial-mesenchymal transition and metastasis in endometrial cancer AN3CA cells by targeting ZEB1.

ABSTRACT

OBJECTIVES: Tumor metastasis is a primary cause of recurrence and mortality in endometrial cancer. miR-34b-5p is abnormally expressed in various cancers and participates in tumor cell progression and metastasis. The objective of this study was to elucidate the biological functions and molecular mechanisms of miR-34b-5p in regulating the epithelial-mesenchymal transition (EMT) and metastasis in AN3CA endometrial cancer cells. METHODS: The expression levels of miR-34b-5p and zinc finger E-box-binding homeobox 1 (ZEB1) in endometrial cancer cells were analyzed by qRT-PCR, and ZEB1 expression in endometrial cancer tissues was examined by immunohistochemistry. Proliferation, migration, and invasion of endometrial cancer AN3CA cells were evaluated using CCK8, scratch, and transwell assays, respectively. Bioinformatic analysis and dual-luciferase reporter gene assays were used to validate the targeting relationship between miR-34b-5p and ZEB1. Western blotting was performed to analyze the expression levels of ZEB1 and EMT-related proteins. RESULTS: miR-34b-5p was significantly downregulated in endometrial cancer AN3CA cells. Overexpression of miR-34b-5p significantly inhibited proliferation, invasion, migration, and the EMT of endometrial cancer AN3CA cells. ZEB1, which was identified as a direct target gene of miR-34b-5p, exhibited high expression in endometrial cancer cells and tissues. Additionally, ZEB1 upregulation partially reversed the inhibitory effects of miR-34b-5p on proliferation, migration, invasion, and the EMT of endometrial cancer AN3CA cells. CONCLUSIONS: miR-34b-5p suppresses the EMT and metastasis in endometrial cancer AN3CA cells by targeting ZEB1, indicating that the miR-34b-5p-ZEB1-EMT axis may be a therapeutic target for endometrial cancer.