Hypoxia Increases KIAA1199/CEMIP Expression and Enhances Cell Migration in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense desmoplasia and hypoxic microenvironment. We previously demonstrated that hyaluronan (HA), especially low-molecular weight HA, provides a favorable microenvironment for progression of PDAC. However, the effect of hypoxia on HA metabolism is unknown. Using quantitative real-time RT-PCR and Western blot analysis, we analyzed changes in expression of HA-synthesizing enzymes (HAS2, HAS3) and HA-degrading enzymes (HYAL1, KIAA1199/CEMIP) in PDAC cell lines under hypoxic condition. Hypoxia increased mRNA and protein expression of KIAA1199, whereas it decreased expression of HYAL1. Expression of HAS2 and HAS3 remained unchanged in response to hypoxia. The effect of KIAA1199 on hypoxia-induced cell migration was determined by transwell migration assay and small-interfering RNA (siRNA). Hypoxia enhanced migratory ability of PDAC cells, which was inhibited by knockdown of KIAA1199 expression. We also used immunohistochemistry to analyze Hypoxia Inducible Factor (HIF) 1α and KIAA1199 protein expression in PDAC tissues. There was a significant immunohistochemically positive correlation between KIAA1199 and HIF1α. These findings suggest that hypoxia-induced KIAA1199 expression may contribute to enhanced motility in PDAC.