Nitric oxide prevents anoxia-induced apoptosis in colonic HT29 cells.

Apoptosis is a critical determinant of tissue mass homeostasis and may play a role in carcinogenesis. The aim of the present study was to investigate anoxia-induced cell death in colon-derived HT29 cells and the effect of nitric oxide on this phenomenon. It was found that HT29 cells subjected to anoxia undergo apoptosis in a time dependent manner, as determined by DNA fragmentation and Hoechst-33258 dye staining. Cytochrome c release from mitochondria to cytosol is a key step in this process and this release precedes DNA fragmentation. NO inhibits anoxia induced apoptosis in these cells by inhibiting the release of cytochrome c and thus may play a role in modulating the apoptotic cell death of colon-derived epithelial cells.