tailieunhanh - Báo cáo Y học: Rapid caspase-dependent cell death in cultured human breast cancer cells induced by the polyamine analogue N1,N11-diethylnorspermine

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. . | Eur. J. Biochem. 269 1033-1039 2002 FEBS 2002 Rapid caspase-dependent cell death in cultured human breast cancer cells induced by the polyamine analogue v1 w11-diethylnorspermine Cecilia Hegardt1 Oskar T. Johannsson2 and Stina M. Oredsson1 1 Department of Animal Physiology Lund University Sweden department of Oncology The Jubileum Institute Lund University Sweden 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 -acetyltransferase SSAT . In the breast cancer cell line L56Br-C1 treatment with 10 M DENSPM induced SSAT activity 60 and 240-fold at 24 and 48 h after seeding respectively which resulted in polyamine depletion. Cell proliferation appeared to be totally inhibited and within 48 h of treatment there was an extensive apoptotic response. Fifty percent of the cells were found in the sub-G1 region as determined by flow cytometry and the presence of apoptotic nuclei was morphologically assessed by fluorescence microscopy. Caspase-3 and caspase-9 activities were significantly elevated 24 h after seeding. At 48 h after seeding caspase-3 and caspase-9 activities were further elevated and at this time point a significant activation of caspase-8 was also found. The DENSPM-induced cell death was dependent on the activation of the caspases as it was inhibited by the general caspase inhibitor Z-Val-Ala-Asp fluoromethyl ketone. The results are discussed in the light of the L56Br-C1 cells containing mutated BRCA1 and p53 two genes involved in DNA repair. Keywords apoptosis breast cancer cells caspase DNA fragmentation N1 N11-diethylnorspermine. The polyamines putrescine spermidine and spermine are cationic molecules that are essential for cell proliferation and differentiation 1 . A number of studies show that they have a role in apoptosis 2-5 as .