Nod-like receptors in head and neck squamous cell carcinoma

Conclusion: The capability of Nod1 to recognize bacteria along with its altered expression and ability to cause an immunological response in head and neck cancer suggest a novel pathway for bacteria to interfere with ongoing cancer inflammation. Objective: Nucleotide oligomerization domain (Nod)-like receptors (NLRs) comprise a recently discovered family of pattern-recognition receptors. In addition to their protective function against infections, accumulating evidence suggests a role for these receptors in various diseases, including cancer. The present study was designed to explore the presence of NLRs in head and neck squamous cell carcinoma, and to determine if these cells have the ability to respond immunologically to ligand stimulation. Methods: The pharyngeal squamous cell carcinoma cell lines Detroit-562 and FaDu were used as a model for head and neck cancer, and compared to healthy primary human nasal epithelial cells. Analyses were performed using immuno-histochemistry, real-time RT-PCR, Luminex Multiplex Immunoassay, ELISA, and flow cytometry. Results: The expression profile of NLRs in head and neck cancer cells differed from that seen in healthy epithelial cells. Further, Nod1 stimulation induced an immunological response in tumor cells that differed from the response in normal epithelial cells, especially regarding the expression of beta-defensin 2, granulocyte monocyte colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), intercellular adhesion molecule-1 (ICAM-1), and cell survival.