miR-1181 inhibits invasion and proliferation via STAT3 in pancreatic cancer

AIM: To examine the role of microRNA 1181 (miR-1181) in invasion and proliferation in pancreatic cancer. METHODS: We analyzed the expression of miR-1181 in several pancreatic cancer cell lines and generated stable MIA-PaCa-2 and PANC-1 cell lines with up-regulated miR-1181 expression using an adenovirus delivery system. We then investigated miR-1181's effect on invasion and proliferation of pancreatic cancer cells by transwell assay, wound healing assay, cell counting kit-8 assay and colony-forming assay, and explored any underlying mechanisms by western bolt. Beyond that, we observed the change of the PANC-1 cell's cytoskeleton by immunofluorescence staining. RESULTS: Our data showed that miR-1181 was relatively down-regulated in pancreatic cancer cell lines compared with normal pancreatic ductal epithelial cells. And miR-1181 inhibited the migration, invasion and proliferation activities of MIA-PaCa-2 and PANC-1 cells. Notably, after over-expressing of miR-1181 in PANC-1 cells, F-actin depolymerized. Immunofluorescence staining shows decreased F-actin and β-tubulin expression in PANC-1 cells over-expressing miR-1181 compared with the control cells. Furthermore, we found that over-expressing miR-1181 inhibited the expression of signal transducer and activator of transcription 3 (STAT3) while knocking-down miR-1181 up-regulated the expression of STAT3. Knocking-down miR-1181 promoted the invasion and proliferation of pancreatic cancer cells. And inhibition of STAT3 blocked the promotion effects of knocking-down miR-1181 on proliferation and invasion in pancreatic cancer. CONCLUSION: Together our findings suggest that miR-1181 may be involved in pancreatic cancer cell invasion and proliferation by targeting STAT3 and indicate that miR-1181 may be a potential therapeutic agent for pancreatic cancer.