Pyrazoloacridine (NSC 366140), an intercalating agent with anti-cancer activity, inhibits the activity of topoisomerases 1 and 2. Pyrazoloacridine (NSC 366140) exhibits an IC50 of 1.25 μM in K562 myeloid leukemia cells for 24 h treatment[1][2].
[1] J S Sebolt, et al. Pyrazoloacridines, a new class of anticancer agents with selectivity against solid tumors in vitro. Cancer Res. 1987 Aug 15;47(16):4299-304. PMID:2440564
[2] A A Adjei, et al. Effect of pyrazoloacridine (NSC 366140) on DNA topoisomerases I and II. Clin Cancer Res. 1998 Mar;4(3):683-91. PMID:9533538
