The multifaceted roles of nitric oxide in cancer

The roles of nitric oxide (NO) in numerous disease states have generatedconsiderable discussion over the past several years. NO has been labeled asthe causative agent in different pathophysiological mechanisms, yet appearsto protect against various chemical species such as those generated underoxidative stress. Similarly, NO appears to exert a dichotomy of effectswithin the multistage model of cancer. Chronic inflammation can lead to theproduction of chemical intermediates, among them NO, which in turn canmediate damage to DNA. Yet, NO also appears to be critical for thetumoricidal activity of the immune system. Furthermore, NO can also have amultitude of effects on other aspects of tumor biology, includingangiogenesis and metastasis. This report will discuss how the chemistry ofNO may impact the initiation and progression stages of cancer.