title: Acute effects of mitoxantrone on the template activity of isolated nuclei from the T-47D human breast tumor cell line.
abstract: The effect of mitoxantrone on the template activity of nuclei isolated from the T-47D human breast tumor cell line was investigated. The results suggest that mitoxantrone significantly inhibits total RNA synthesis of these nuclei in a concentration-dependent manner. At low drug concentrations (10(-9) M and 10(-7) M) RNA synthesis was inhibited by 21.9% and 41% compared to control values, respectively. Greater inhibition was observed when the mitoxantrone concentration was increased to 10(-5) M or 10(-4) M (56% and 77%, respectively). Experiments utilizing alpha-amanitin revealed that mitoxantrone inhibits RNA polymerase II activity in a concentration-dependent manner.
mesh_terms: D000880:Anthraquinones / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors; D005260:Female; D006801:Humans; D008942:Mitoxantrone; D012313:RNA / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D000880:Anthraquinones; D000970:Antineoplastic Agents; D012313:RNA; D008942:Mitoxantrone; D012321:DNA-Directed RNA Polymerases