title: Chemically modified tetracyclines induce cytotoxic effects against J774 tumour cell line by activating the apoptotic pathway.
abstract: Here, we have studied the effects of chemically modified tetracyclines (CMTs) on apoptosis both at the level of the cytoplasmic proteolytic caspase cascade, and on Bcl-2 and c-myc mRNA expression in the J774 macrophage cell line. The results indicate that CMTs induce morphological changes consistent with apoptotic events, as clearly demonstrated both by the acridine orange and ethidium bromide staining, and by TUNEL and fragmentation ELISA assays. Furthermore, the analysis of the cell cycle by flow cytometry shows an evident apoptotic sub-G0G1 peak, without important modifications in the cell cycle distribution. CMTs induce programmed cell death (PCD) in a dose-dependent manner and CMT-8 is the strongest among them. CMT-1 and CMT-8 activate mainly caspase-8 as attested by the inhibitory effects of Z-VAD-fmk and Z-IEDT-fmk on CMT-induced apoptosis. Part of CMT-induced PCD is due to the activation of caspase-9, since it is reduced by the specific caspase-9 inhibitor, Z-LEHD-fmk. Besides, CMTs increase Bcl-2 and c-myc mRNA expression. Collectively, these data indicate that CMTs are potentially anti-tumour agents, since they strongly trigger apoptosis both activating the proteolytic system of the caspase family and modulating genes involved in PCD regulation.
authors.affiliation: Department of Immuno-Haematology and Transfusion, University of Palermo, Palermo, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: D'Agostino
authors.forename: Viviana
authors.initials: V
authors.lastname: Ferlazzo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Milano
authors.forename: Marzia
authors.initials: M
authors.lastname: La Rosa
authors.forename: Gloria
authors.initials: G
authors.lastname: Di Bella
authors.forename: Rosalba
authors.initials: R
authors.lastname: Caruso
authors.forename: Caterina
authors.initials: C
authors.lastname: Barbera
authors.forename: Stefania
authors.initials: S
authors.lastname: Grimaudo
authors.forename: Manlio
authors.initials: M
authors.lastname: Tolomeo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Feo
authors.forename: Enrico
authors.initials: E
authors.lastname: Cillari
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D017737:Macrophages, Peritoneal / Q000187:drug effects; D051379:Mice; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D013752:Tetracycline / Q000494:pharmacology*; D013754:Tetracyclines / Q000737:chemistry* / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D013754:Tetracyclines; C117153:tetracycline CMT-8; C053450:4-des-dimethylaminotetracycline; D020169:Caspases; D013752:Tetracycline