Topoisomerase IIα-IN-4 (F2) is a non-intercalative ATP-competitive inhibitor of human DNA topoisomerase II, specifically inhibiting TopoIIα with an IC50 value of 3.8 μM and TopoIIβ with an IC50 value of 10.1 μM. It demonstrates significant efficacy in inducing apoptosis and arresting the cell cycle in HepG2 cells. Moreover, Topoisomerase IIα-IN-4 exhibits robust antitumor effects against various human cancer cell lines, making it a valuable compound for cancer research [1].
Topoisomerase II inhibitor 3 (Compound 6 h) is an acridone derivative that acts as a Type II DNA topoisomerase (topo II) inhibitor. It specifically inhibits the topo IIα/β subtypes, with an IC50 value of 0.17 μM for topo IIα and 0.23 μM for topo IIβ. This compound elicits significant DNA damage and induces apoptosis by triggering the loss of mitochondrial membrane potential [1].