MiR-185-3p regulates epithelial mesenchymal transition via PI3K/Akt signaling pathway by targeting cathepsin D in gastric cancer cells

BACKGROUND: Recently research reported that miR-185-3p could serve as an independent prognosis factor in gastric cancer (GC). However, the functional role and underlying mechanism of miR-185-3p in GC and epithelial-mesenchymal transition (EMT) progression remains largely elusive. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to analyze the expression of miR-185-3p and cathepsin D in patient-derived GC samples and various GC cell lines. Scratch assay and Transwell assay were used to evaluate the migration ability. The influence of miR-185-3p on the cell cycle distribution and cell apoptosis was evaluated using flow cytometry. Western blotting assay was performed to detect the expression of EMT associated proteins and the activity of PI3K/Akt signaling pathway. Furthermore, the interaction between miR-185-3p and cathepsin D was explored by dual-luciferase reporter assay. RESULTS: Our data revealed that miR-185-3p was down-regulated, while cathepsin D was up-regulated in both patient-derived GC samples and GC cells. Apart from inducing apoptosis, overexpression of miR-185-3p also inhibited EMT process and migration of GC cells. Mechanically, we firstly verified that miR-185-3p directly targeted the cathepsin D. Furthermore, miR-185-3p exerted its function on EMT process and migration via inhibiting cathepsin D to mediated PI3K/Akt signaling pathway. CONCLUSIONS: Our findings suggested that miR-185-3p targeted cathepsin D inhibiting EMT process via PI3K/Akt signaling, which may serve as a potential prognosis factor and therapeutic target to reduce the malignancy of GCs.