Mir-320b Inhibits Pancreatic Cancer Cell Proliferation by Targeting FOXM1

Background: Pancreatic Ductal Adenocarcinoma (PDAC) is the most common and deadly cancer. Surgical resection is the only possible cure for pancreatic cancer but often has a poor prognosis, and the role of adjuvant therapy is urgently explored. Methods: MicroRNAs (miRNAs) play a very important role in tumorigenesis by regulating the target genes. In this study, we identified miR-320b lower-expressed in human pancreatic cancer tissues but relatively higher-expressed in the adjacent non-tumor tissues. Results: Consistently, the expression of miR-320b in different pancreatic cancer cell lines was significantly lower than the normal pancreatic cells. In order to identify the effects of miR-320b on cell growth, we overexpressed miR-320b in PANC-1 and FG pancreatic cancer cell lines, CCK8 and BrdU incorporation assay results showed that miR-320b inhibited cell proliferation. Discussion: We next predicted miR-320b targeted FOXM1 (Forkhead box protein M1) and identified the negative relationship between miR-320b and FOXM1. We also demonstrated that elevated miR- 320b expression inhibited tumor growth in vivo. Conclusion: All of these results showed that miR-320b suppressed pancreatic cancer cell proliferation by targeting FOXM1, which might provide a new diagnostic marker for pancreatic cancer.