The spermine analogue N1,N11-diethylnorspermine (DENSPM) efficiently depletes the cellular pools of putrescine, spermidine and spermine by down-regulating the activity of the polyamine biosynthetic enzymes and up-regulating the activity of the catabolic enzyme spermidine/ spermine N1-acetyltransferase (SSAT). In the breast cancer cell line L56Br-C1, treatment with 10 lM DENSPM induced SSAT activity 60 and 240-fold at 24 and 48 h after seeding, respectively, which resulted in polyamine depletion. .
