Dihydromyricetin Inhibits Proliferation, Migration, and Invasion of Pancreatic Cancer Cells by Regulating miR-509-3p/PRMT5 Pathway

To explore the role of dihydromyricetin (DHM) in regulating proliferation, metastasis and infiltration of pancreatic cancer cells, we treated the pancreatic adenocarcinoma cell line SW1990 with 10 mu mol/L, 20 mu mol/L, and 40 mu mol/L DHM. Proliferation was determined by the MTT assay. Cell metastasis and infiltration were determined by the Transwell migration assay. The protein expression levels of cyclin D1, p21, MMP-2, MMP-9, and PRMT5 were determined by Western blot. Quantitative PCR was used to determine expression of miR-509-3p and PRMT5 mRNA. The relationship between miR-509-3p and PRMT5 was analyzed by bioinformatic prediction and the dual luciferase reporter assay. SW1990 cells were transfected with miR-509-3p, si-PRMT5 and anti-miR-509-3p (following treatment with 40 mu mol/L DHM) to determine their effects on biological behaviors of cells. The inhibition rate of SW1990 cells, p21 protein and miR-509-3p expression were increased by DHM. Moreover, the number of infiltrating and metastatic cells, protein levels of cyclin D1, MMP-2, MMP-9, and PRMT5, and mRNA levels of PRMT5 were decreased by DHM. miR-509-3p regulates expression of its target PRMT5 mRNA. Inhibition rate of SW1990 cell proliferation and protein level p21 were significantly increased by overexpression of miR-509-3p or knockdown of PRMT5 expression, while the number of invasive cells and protein expression levels of cyclin D1, MMP-2 and MMP-9 were remarkably reduced by miR-509- 3p overexpression or PRMT5 knockdown. Inhibition of miR-509-3p counteract the inhibitory effects of DHM on SW1990 cell proliferation and metastasis. Therefore, DHM inhibits proliferation and metastasis of pancreatic carcinoma cells by regulating the miR-509-3p/PRMT5 pathway.