Antizyme prevents ornithine decarboxylase-mediated cell death in human fibroblasts

Ornithine decarboxylase (ODC) is a key enzyme of polyamine biosynthesis essential for growth-related cellular functions. Apart from its physiological role in cell proliferation, ODC also contributes to the induction of apoptosis under certain conditions, e.g. following growth factor withdrawal. The rate of cell death is a function of its enzyme activity. ODC activity is inhibited by a regulatory protein antizyme, also known to suppress polyamine uptake. We report that forced expression of ‘antizyme’ prevents ODC-mediated cell death in human gingival fibroblasts under very low serum conditions. These data suggest an important antiapoptotic role for antizyme in cell survival.