Effect And Mechanism Of Interleukin-9 Promotes Pancreatic Cancer Cells Proliferation And Metastasis

Objectives This study was to investigate the impact and mechanism of interleukin-9（IL-9）on proliferation,migration and invasion of pancreatic cancer cells,and to explore the role of JAK/STAT3 pathway in the proliferation,migration and invasion of pancreatic cancer cells.To further determine whether IL-9 activates JAK/STAT3 pathways plays a role in promoting the growth of pancreatic cancer cells.Methods Human pancreatic cancer cell line PANC-1 was used as the research object.PANC-1 cells were cultured in vitro and treated with IL-9 at different concentrations of 0、5ng/mL、10ng/mL、20ng/mL for 24h.CCK-8assay was used to test the proliferation of cells.The level of IL-9R mRNA was analyzed by quantitative real-time PCR and the apoptosis of cells was detected by flow cytometry.Transwell^TM method was employed to test the migration and invasion abilities of the cells.After 0、5ng/mL、10ng/mL、20ng/mL of IL-9interferring with PANC-1 for 1h respectively,Western blot was used to detect the STAT3 and p-STAT3 protein expression levels.In the mechanism study of IL-9,PANC-1 cells were pretreated with STAT3 pathway inhibitor（AG490）at different concentrations of 0、20μmol/L、40μmol/L、80μmol/L for 24h,and then intervened with 20ng/mL IL-9 for 1h,the STAT3 and p-STAT3 protein expression were detected by Western blot.After 24 hours of intervention,cell proliferation was detected by CCK-8.The proliferation of pre-inhibitor cells and the changes of STAT3 and p-STAT3 protein expression were compared.Results The level of IL-9R mRNA and rate of PANC-1 cells proliferation were increased with the enhancement of IL-9 concentration,and both were significantly greater than 0ng/mL at 20ng/mL（P<0.05）.As well as the capacity of cell migration and invasion showed a concentration-dependent increase trend,the difference was most significant at 20ng/mL（P<0.05）.The mortality rate decreased with increasing concentrations,but there was no significant difference among the concentrations（P>0.05）.Compared with the control group,the relative protein expression of p-STAT3 was increased greatly in PANC-1 cells with treatment of IL-9（P<0.05）,but STAT3 was not changed significantly compared with those without IL-9 treatment（P>0.05）,suggesting that IL-9 may promote STAT3 phosphorylation during pancreatic cancer cell proliferation.Comparing the proliferation rate of cells before using inhibitors,the proliferation of AG490-pretreated PANC-1 cells induced by IL-9 was notably inhibited at 80μmol/L（P<0.05）,and the p-STAT3 protein expression levels was significantly decreased（P<0.05）,but there was no significant difference in the expression of STAT3 protein among the groups（P>0.05）.Conclusions IL-9 may activate the JAK/STAT3 pathway to promote the proliferation,migration and invasion of pancreatic cancer cells but has little effect on apoptosis,which is in a dose-dependent manner.This study has deeeply understanding of JAK/STAT3 in pancreatic cancer and provides the basis for further research on pancreatic cancer.