Ornithine Decarboxylase: Alterations In Carcinogenesis

Abstract

The diamine putrescine, the tertiary amine spermidine, and the quaternary amine spermine (collectively referred to as the polyamines) are small, aliphatic, nonprotein nitrogenous bases found in all living cells (1,2). Because of their polycationic nature, they can form tight, noncovalent complexes with negatively charged cellular constituents, such as nucleic acids and proteins. This electrostatic binding is the basis of the known essential roles that polyamines play in nucleic acid and protein synthesis, structure, and function (3,4). In contrast to the inorganic cations, which must be supplied to the cell by the circulation, the polyamines can be synthesized by the cells at times of cellular need. The primary mechanism for a cellular increase in polyamine content is an increase in the activity of ornithine decarboxylase (ODC) which catalyzes the formation of putrescine from ornithine.