Inhibiting Interleukin-19 Activity Ameliorates Esophageal Squamous Cell Carcinoma Progression

Background:IL-19 is expressed in esophageal squamous cell carcinoma (SCC), but its biological effect on esophageal cancer remains unclear. We determined the correlation between IL-19 expression levels and clinicopathological variables and explored the effects of IL-19 on the esophageal SCC in vivo and in vitro.Methodology/Principal Findings:We determined the expression levels of esophageal SCC tissues from 60 patients using immunohistochemistry. We examined the effects of IL-19 on intracellular signaling, cytokines production as well as proliferation, colonization, and migration in the human esophageal SCC cell line CE81T. Monoclonal antibodies (mAbs) against IL-19 (1BB1) and its receptor IL-20R1 (51D) were used to antagonize the effects of IL-19. We injected SCID mice with CE81T cells and then treated them with anti-IL-19 mAb or control IgG every 3 days and determined tumor growth for 32 days. Of the 60 esophageal SCC patients, 36 patients (60%) were IL-19 strongly stained, which was associated with advanced tumor stage. CE81T cells expressed IL-19 and its receptors. IL-19 induced phosphorylation of STAT3, P38, JNK, ERK1/2, Akt, and NF-κB in CE81T cells. IL-19 promoted the proliferation, colonization, and migration of CE81T cells, which were antagonized by 1BB1 and 51D. IL-19 also induced expression of the transcripts of TGF-β, cyclin B1, CXCR4, and MMP-1 in CE81T cells. In CE81T tumor-bearing mice, 1BB1 reduced tumor growth and downregulated TGF-β, cyclin B1, MMP-1, and CXCR4 expression in tumors.Conclusions/Significance:IL-19 affects the pathogenesis of esophageal cancer. IL-19 mAb (1BB1) is potentially a potent drug for esophageal cancer therapy.