Ornithine decarboxylase (ODC) is the first and rate-limiting enzyme of polyamine biosynthesis. Polyamines (putrescine, spermidine, etc) are essential for cell growth. ODC has a very short half-life due to a strong interaction with ODC antizyme 1 (OAZ1) that prevents its homodimerisation and promotes destruction of the monomer units by the 26S proteasome [, ]. In addition to its effects on ODC, OAZ1 also negatively regulates polyamine transport into cells [, ]. By regulating ODC activity, OAZ1 is considered a tumour suppressor gene [].
