Micro(mi)RNAs play a critical regulatory role in the progression and metastasis of pancreatic cancer (PC). In this study, we aimed to reveal the mechanisms of miR-374b-5p in regulating epithelial-mesenchymal transition (EMT) in PC. Gene Expression Omnibus datasets (GSE24279 and GSE71533) and the pancreatic ductal adenocarcinoma (PDAC) cohort of The Cancer Genome Atlas were employed to screen for potential prognostic miRNAs. The expression of miR-374b-5p was measured by quantitative real-time polymerase chain reaction (qRT-PCR) in 78 paired PDAC tissue samples. The biological effects of miR-374b-5p were investigated using in vitro and in vivo assays. Luciferase reporter assays and immunohistochemical tests were conducted to verify the interaction between miR-374b-5p and its predicted direct target, KDM5B. MiR-374b-5p was downregulated in PC tissues, and a low level of miR-374b-5p was associated with poor overall survival, greater tumor size, and more lymph node metastasis in PC. In vitro assays indicated that overexpression of miR-374b-5p suppressed the proliferation, migration, and invasion of PC cells. Mechanistically, miR-374b-5p suppressed the expression of KDM5B, which inhibited E-cadherin expression but promoted N-cadherin and vimentin expression. Finally, in vivo assays demonstrated that miR-374b-5p overexpression suppressed tumor growth and lung metastasis in PANC-1 cells. Thus, our findings indicate that miR-374b-5p could be a potential prognostic biomarker and therapeutic target for KDM5B-induced EMT in PC.
Keywords: KDM5B; epithelial-mesenchymal transition; miR-374b-5p; pancreatic cancer.
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