N-Myc downstream-regulated gene 2 (NDRG2) is a negative regulator of cell growth and its expression is decreased in cancers

Using subtraction cloning, we identified the human N-Myc Downstream- Regulated Gene-2 (hNDRG2), located at 14q11.2, as a candidate tumor suppressor gene. Semi-quantitative RT-PCR showed that the expression of hNDRG2 in 15 of 27 (56%) human GBM tissues and all 6 human glioblastoma cell lines was significantly lower than that in the normal brain. The expression of hNDRG2 also was evaluated in 60 lung-carcinoma patients. 17 of 26 cases of squamous carcinoma and 4 of 11 cases of small cell lung cancer displayed     

Nitrite is a signaling molecule and regulator of gene expression in mammalian tissues

Mammalian tissues produce nitric oxide (NO) to modify proteins at heme and sulfhydryl sites, thereby regulating vital cell functions. The majority of NO produced is widely assumed to be neutralized into supposedly inert oxidation products including nitrite (NO2(-)). Here we show that nitrite, also ubiquitous in dietary sources, is remarkably efficient at modifying the same protein sites, and that physiological nitrite concentrations account for the basal levels of these modifications in vivo. We further find that nitrite readily affects cyclic GMP production, cytochrome P450 activities, and heat shock protein 70 and heme oxygenase-1 expression in a variety of tissues. These cellular activities of nitrite, combined with its stability and abundance in vivo, suggest that this anion has a distinct and important signaling role in mammalian biology, perhaps by serving as an endocrine messenger and synchronizing agent. Thus, nitrite homeostasis may be of great importance to NO biology.