Polyamine acetylation in rat brain during N-ethyl-N-nitrosourea-induced cerebral carcinogenesis

The behavior of cerebral polyamine acetylation was examined in rat brain during N-ethyl-N-nitrosourea-induced carcinogenesis. Before tumor development, treated brains exhibited an enhancement in cytosolic spermidine/spermine N1-acetyl-transferase activity with concomitant accumulation of N1-acetylspermidine and increases in putrescine and spermidine. This indicates a stimulation of the interconversion pathway of polyamines into putrescine, an important molecule for cell growth. Our data also show the presence of a cytosolic spermidine N8-acetyltransferase activity in fetal rat brain, with values similar to those previously observed in gliomas. The detection of cytosolic spermidine N8-acetyltransferase activity in tumors may thus represent the expression of a fetal gene that does not seem to have a particular function during carcinogenesis.