MiR-203a-3p Inhibits Pancreatic Cancer Cell Proliferation, EMT, and Apoptosis by Regulating SLUG

OBJECTIVE: The aim of the present research is to study the roles of miR-203a-3p on cell proliferation, migration, invasion, and epithelial–mesenchymal transition in pancreatic cancer. METHODS: Transcription profiles were acquired from Gene Expression Omnibus database, which was used to screen out the differentially expressed microRNAs and messenger RNAs in pancreatic cancer. Pancreatic cancer tissues were used to verify the bioinformatics results by quantitative real-time polymerase chain reaction. The relationship between miR-203a-3p and SLUG was examined by TargetScan software, dual-luciferase reporter assay, and RNA immunoprecipitation. The Cell Counting Kit-8, wound healing, and transwell assays were conducted to investigate the proliferation, migration, and invasion capability of pancreatic cancer cells, respectively. The expression of epithelial–mesenchymal transition–related proteins was determined by the Western blot assay. Xenograft assay was performed to verify findings from in vitro assays. RESULTS: Bioinformatic analysis found that a total of 113 microRNAs and 1749 messenger RNAs expressed differentially in pancreatic cancer tissues. Among these microRNAs, the expression of miR-203a-3p was significantly decreased in both pancreatic cancer tissues and cells. On the other hand, the SLUG expression was remarkably upregulated in pancreatic cancer tissues and cells in comparison with normal tissues and cells. Moreover, TargetScan software, dual-luciferase reporter assay, and RNA immunoprecipitation revealed that SLUG was a target of miR-203a-3p. The upregulation of miR-203a-3p expression inhibited the proliferation, migration, and invasion ability of pancreatic cancer cells by suppressing the epithelial–mesenchymal transition process via sponging SLUG. CONCLUSION: These findings indicate that downregulation of miR-203a-3p in pancreatic cancer cells leads to high expression of SLUG, which promotes epithelial–mesenchymal transition process and induces cancer progression.