Activation of Toll-Like Receptor 2 Promotes Proliferation of Human Lung Adenocarcinoma Cells
Anna K. Gergen, Patrick D. Kohtz, Alison L. Halpern, Anqi Li, Xianzhong Meng, T. Brett Reece, David A. Fullerton, Michael J. Weyant
Abstract
BACKGROUND/AIM: The aim of this study was to evaluate the role of toll-like receptor 2 (TLR2) in the proliferation of human lung cancer cells and identify the signaling pathway that mediates this effect. MATERIALS AND METHODS: Adenocarcinoma (A549 and H1650) and adenosquamous (H125) cells were treated with increasing doses of Pam3CSK4, a TLR2 agonist. Cell proliferation and NF-ĸB activation were evaluated. NF-ĸB was inhibited prior to treatment with Pam3CSK4 and proliferation was assessed. RESULTS: TLR2 expression was significantly higher in A549 and H1650 cells compared to H125 cells (p<0.001). TLR2 stimulation induced proliferation in adenocarcinoma cells only and led to a corresponding increase in NF-ĸB activity (p<0.05). Inhibition of NF-ĸB prior to treatment with Pam3CSK4 attenuated this proliferative response. CONCLUSION: TLR2 activation induced proliferation of lung adenocarcinoma cells through activation of NF-ĸB. Thus, the TLR2 signaling pathway may be a potential therapeutic target in lung adenocarcinoma.