Background: In our previous study, it was suggested that nitrotyrosine, a product of nitrogen species, found in esophageal squamous cell carcinoma (ESCC), may contribute to the progression of esophageal cancer.
Materials and methods: To clarify whether nitrotyrosine expression is associated with apoptosis and/or angiogenic factors in ESCC, we have analyzed the relationship between nitrotyrosine presence and the apoptosis-related proteins, Bcl-2 and Bax, or CD34, the marker of vascular endothelial cells, by an immunohistochemical approach.
Results: Nitrotyrosine was detected in 21 out of 55 esophageal cancers. The correlation between nitrotyrosine presence and Bcl-2, Bax expression or apoptotic index (AI) was not significant. In contrast, nitrotyrosine presence was significantly correlated with the microvessel density (MVD); nitrotyrosine-positive specimens tended to show a high MAD, while nitrotyrosine-negative specimens tended to be associated with a low MVD (p<0.05).
Conclusion: Our data suggest that NO induces progression of esophageal carcinoma through its effect on angiogenesis, rather than its effect on tumor apoptosis.