IL-9 PROMOTES THE GROWTH OF PANCREATIC CANCER CELLS BY ACTIVATING THE JAK/STAT3 PATHWAY

Jian Hou^#, Hailong Liu^{#, *}, Qi Zhang

Department of Oncology, The First People's Hospital of Chenzhou City, Hunan Province, 423000, China

Objective: To explore the effect and mechanism of interleukin 9 (IL-9) on the growth of pancreatic cancer cells by activating Janus kinase (JAK)/signal transduction and transcription activator 3 (STAT3) pathway.

Methods: Human pancreatic cancer cell line PANC-1 was collected for routine passage, freezing, and resuscitation. PANC-1 cells were then randomly divided into an NC group, a 5 ng/mL IL-9 group, a 10 ng/mL IL-9 group, and a 20 ng/mL IL-9 group. The NC cell group was a blank control without any treatment, while the 5 ng/mL IL-9 group, 10 ng/mL IL-9 group, and 20 ng/mL IL-9 group cells were respectively treated with 5, 10, and 20 ng/mL concentration IL-9 for 24 hours. The cell proliferation rate, apoptosis rate, IL-9R mRNA expression level, and expression levels of STAT3 signaling pathway-related proteins such as p-STAT3 and STAT3 were compared across the groups. The remaining PANC-1 cells were randomly divided into a 0 μmol/L AG490 (a JAK/STAT3 signaling pathway blocker) group, a 20 μmol/L AG490 group, a 40 μmol/L AG490 group, and an 80 μmol/L AG490 group, which respectively received 0, 20, 40, and 80 μmol/L AG490 treatment for 24 hours. Differences in cell proliferation rate and expression levels of STAT3 signaling pathway-related proteins such as p-STAT3 and STAT3 were then compared.

Results: The proliferation rate of PANC-1 cells in the 10 ng/mL IL-9 group and 20 ng/mL IL-9 group was significantly higher than that in the NC group (P<0.05). The proliferation rate of PANC-1 cells in the 5 ng/mL IL-9 group was not statistically different from that of the NC group (P>0.05). The apoptosis rate of PANC-1 cells in the IL-9 concentration group was not statistically different from cells of the NC group (P>0.05). The expression levels of IL-9R mRNA in PANC-1 cells of the 10 ng/mL IL-9 group and 20 ng/mL IL-9 group were significantly higher than in cells of the NC group (P<0.05). The IL-9R mRNA expression level of PANC-1 cells in the 5 ng/mL IL-9 group was not significantly different from that of cells in the NC group (P>0.05). The expression levels of p-STAT3 protein in PANC-1 cells of 10 ng/mL IL-9 group and 20 ng/mL IL-9 group were significantly higher than in the NC group (P<0.05). The expression level of STAT3 protein in PANC-1 cells in IL-9 concentration group was not significantly different from that of cells in the NC group (P>0.05). The PANC-1 cell proliferation rate and p-STAT3 protein expression level in the 80 μmol/L AG490 group were significantly lower than those in the 0 μmol/L AG490 group (P<0.05). There was no significant difference in the expression level of STAT3 protein in PANC-1 cells of the AG490 concentration group (P>0.05).

Conclusion: IL-9 can promote the growth of pancreatic cancer cells, which may be achieved by activating the JAK/STAT3 signaling pathway.