Irinotecan Hcl-trihydrate prevents DNA from unwinding by inhibition of topoisomerase 1.

Tubulin inhibitor 35 (Tubulin IN 35) is a potent dual inhibitor of topoisomerase I and microtubule protein polymerization with antitumor activity, inhibits migration and invasion of MGC-803 and RKO cell lines, interrupts the cell cycle and induces apoptosis.

Chloroquinoxaline sulfonamide (Chloroquinoxaline) is a topoisomerase II alpha/beta toxin with antitumor activity and immunosuppressive properties that inhibits the proliferation of B16 melanoma cells in mice, and can be used to study metastatic colorectal cancer.