Background: Head and neck squamous cell carcinoma (HNSCC) ranks as the sixth most frequent malignancy worldwide. High levels of nitric oxide (NO) has been identified in many types of human cancers including HNSCC. In this study, we investigated the effect of NO on promoter DNA methylation in cell lines of HNSCC.

Materials and Methods: The methylation status of the promoters of E-cadherin, RASSF1A and MGMT were analyzed in the parent and high nitric oxide (HNO) adapted cell lines of HNSCC using Illumina MiSequencing.

Results: We detected difference in promoter methylation levels of MGMT between the parent and HNO adapted cell lines (p<0,0001). However, treatment of the cell lines with NO did not significantly change methylation of E-cadherin and MGMT.

Conclusion: Our results suggest that NO may have diverse actions on DNA methylation. Further studies are required to clearly understand the role of NO in epigenetic alterations of HNSCC.