Prolongation Effect of Nitric Oxide on Survival of Primary and Metastatic Head and Neck Cancer Cell Lines

Nitric oxide (NO) is a free radical which plays key role in various physiological as well as pathological processes. NO has emerged as one of the most important molecules influencing the development and progression of cancers. Head and neck squamous cell carcinoma (HNSCC) is one of cancer that shows high incident and mortality rate worldwide. We aimed to investigate effect of NO on genetically matched of primary and metastatic HNSCC cell lines. The cell lines were derived from three pairs of primary (HN4, HN18 and HN30) and their metastatic sites (HN12, HN17 and HN31), respectively. The incremental doses of the NO donor, DETA-NONOate, (10-3,000 µM) were treated to the cancer cells for 72 h. Cell proliferation was measured using MTT assay. The results showed that all of HNSCC cell lines could survive at the tested concentrations of DETA-NONOate. All of primary cancer cells were significantly decreased in cell proliferation at 100-600 µM DETA-NONOate compared to the controls (P<0.05). In contrast, their metastatic cells able to proliferate in the presence of high doses of DETA-NONOate (150-600 µM). Interestingly, HN17 could prolong survives at 600 µM DETA-NONOate but significantly decreased in proliferation at 1,000 µM compared to the control (P<0.05). In conclusion, our data indicate that metastatic HNSCC cells can resist to the high doses of NO compare to their primary counterpart cells.