[Interleukin-9 promotes pancreatic cancer cell proliferation and migration via activation of STAT3 pathway]

Objective To investigate the impact of interleukin-9 (IL-9) on proliferation, invasion and migration of pancreatic cancer cells and its mechanism. Methods PANC-1 cells were cultured in vitro and treated with IL-9 at different concentrations (5, 10, 20 ng/mL) for 24 hours. The level of IL-9R mRNA was analyzed by quantitative real-time PCR. CCK-8 assay was used to test the proliferation of the cells and flow cytometry to detect the cell apoptosis. Transwell^TM assay was employed to determine the invasion and migration of PANC-1 cells. Western blotting was used to detect the STAT3 and p-STAT3 protein expression levels. After PANC-1 cells were treated with different concentrations of STAT3 pathway inhibitor AG490, followed by IL-9 treatment, the STAT3 and p-STAT3 protein expressions, as well as the proliferation of the cells were detected again. Results The level of IL-9R mRNA and the proliferation rate of PANC-1 cells were enhanced with the increase of IL-9 concentration, and the capacities of cell invasion and migration were promoted significantly. The relative protein expression of p-STAT3 increased greatly in PANC-1 cells after the treatment of IL-9, but STAT3 were not changed significantly compared with the ones without IL-9 treatment. The proliferation-promoting effect of IL-9 on AG490-pretreated PANC-1 cells was induced, and the p-STAT3 protein expression level was notably inhibited. Conclusion The activation of STAT3 pathway is strongly associated with the process that IL-9 mediates the promotion of proliferation, invasion and migration in pancreatic cancer cells.