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 α-amanitin revealed that mitoxantrone inhibits RNA polymerase II activity in a concentration-dependent manner.
ASJC Scopus subject areas
- Cancer Research