title: Rapid caspase-dependent cell death in cultured human breast cancer cells induced by the polyamine analogue N(1),N(11)-diethylnorspermine.
abstract: The spermine analogue N(1),N(11)-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 N(1)-acetyltransferase (SSAT). In the breast cancer cell line L56Br-C1, treatment with 10 microm 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-G(1) 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.
authors.affiliation: Department of Animal Physiology, Lund University, Sweden. Cecilia.Hegardt@zoofys.lu.se
authors.forename: Cecilia
authors.initials: C
authors.lastname: Hegardt
authors.forename: Oskar T
authors.initials: OT
authors.lastname: Johannsson
authors.forename: Stina M
authors.initials: SM
authors.lastname: Oredsson
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000187:drug effects / Q000378:metabolism*; D016923:Cell Death; D002455:Cell Division / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D019398:Genes, BRCA1; D006801:Humans; D011073:Polyamines; D013096:Spermine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D011073:Polyamines; D013096:Spermine; C052614:N(1), N(12)-diethylspermine; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases