Toll-like receptor 9 agonists promote IL-8 and TGF-β1production via activation of nuclear factor κB in PC-3 cells

Chronic infection and resulting inflammation promote tumor development and progression, and Toll-like receptors (TLRs) may play an important role in this process. The aim of this study was to determine whether CpG oligonucleotides (CpG-ODN), which are Toll-like receptor 9 (TLR9) agonists, can promote inflammatory cytokines release from the prostate cancer PC-3 cells through activation of nuclear factor-κB (NF-κB). Flow cytometry, semiquantitative real-time reverse transcriptase–polymerase chain reaction, enzyme-linked immunosorbent assay, and immunofluorescence analysis were used to detect the transforming growth factor-β1 (TGF-β1) and interleukin-8 (IL-8) release and NF-κB activation in PC-3 cells after CpG-ODN stimulation. CpG-ODN promoted the expression and secretion of immunosuppressive cytokines TGF-β1 and IL-8 from PC-3 cells. In addition, after CpG-ODN stimulation, NF-κB nuclear translocation was also observed in PC-3 cells, contributing to CpG-induced upregulation of IL-8 and TGF-β1. Thus, TLR9 agonists may promote IL-8 and TGF-β1 production in human prostate cancer cells through NF-κB activation.