IL22RA1/STAT3 Signaling Promotes Stemness and Tumorigenicity in Pancreatic Cancer

Chronic inflammation is a feature of pancreatic cancer, but little is known about how immune cells or immune cell-related signals affect pancreatic cancer stemness and development. Our previous work showed that IL22/IL22RA1 plays a vital role in acute and chronic pancreatitis progression by mediating cross-talk between immune cells and acinar cells or stellate cells, respectively. Here, we find IL22RA1 is highly but heterogeneously expressed in pancreatic cancer cells, with high expression associated with poor prognosis of patients with pancreatic cancer. The IL22RA1(hi) population from pancreatic cancer harbored higher stemness potential and tumorigenicity. Notably, IL22 promoted pancreatic cancer stemness via IL22RA1/STAT3 signaling, establishing the mechanism of regulation of cancer stemness by microenvironmental factors. Moreover, STAT3 was indispensable for the maintenance of IL22RA1(hi) cells. Overall, these findings provide a therapeutic strategy for patients with PDAC with high expression of IL22RA1. Significance: IL22RA1/STAT3 signaling enhances sternness and tumorigenicity in pancreatic cancer. (C) 2018 AACR.