title: Radiation-induced apoptosis in MOLT-4 cells requires de novo protein synthesis independent of de novo RNA synthesis.
abstract: We investigated the effects of inhibition of de novo RNA and protein synthesis in ionizing radiation (IR)-induced apoptosis in the human T cell line MOLT-4. We observed that pretreatment with cycloheximide inhibited IR-induced apoptosis. However, pretreatment with actinomycin D did not inhibit apoptosis induced by IR. These results suggest that apoptosis induced by IR in MOLT-4 cells requires de novo protein synthesis but not de novo RNA synthesis. This finding suggests that the mRNA encoding the proapoptotic protein(s) is stabilized to facilitate translation independent of de novo gene transcription in response to IR. Our results also indicate that translation of the required proapoptotic protein(s) occurs upstream of mitochondrial depolarization and after 2 h post-IR.
authors.affiliation: Department of Microbiology, Room 751 WIDB, Brigham Young University, University Ave., Provo, UT 84602, USA.
authors.forename: Matthew Hiram
authors.initials: MH
authors.lastname: Taylor
authors.forename: Matthew Ross
authors.initials: MR
authors.lastname: Buckwalter
authors.forename: Amen Craig
authors.initials: AC
authors.lastname: Stephenson
authors.forename: Janet Leigh
authors.initials: JL
authors.lastname: Hart
authors.forename: Benjamin James
authors.initials: BJ
authors.lastname: Taylor
authors.forename: Kim Leslie
authors.initials: KL
authors.lastname: O'Neill
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D005720:Gamma Rays; D006801:Humans; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012313:RNA / Q000096:biosynthesis*; D020871:RNA Stability; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D013997:Time Factors
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D012313:RNA