TAS-103 is a dual inhibitor of DNA topoisomerase I/II, used for cancer research.

TAS-103 is a dual inhibitor of DNA topoisomerase I/II. TAS-103 (0.1-10 μM) is active on CCRF-CEM cells, with an IC50 value of 5 nM. TAS-103 (0.1 μM) significantly increases levels of topo IIα FITC immunofluorescence in individual CCRF-CEM cells[1]. TAS-103 (0.01-1 μM) is highly cytotoxic to Lewis lung carcinoma (LLC) cells, and Liposomal TAS-103 is almost as active as free TAS-103[2]. TAS-103 inhibits the viability of HeLa cells, with an IC50 of 40 nM. TAS-103 (10 μM) disrupts signal recognition particle (SRP) complex formation, and induces destabilization of SRP14 and SRP19 and its eventual degradation[3].

TAS-103 (30 mg/kg, i.v.) causes significant tumor growth suppression in mice bearing Lewis lung carcinoma (LLC) cells, without obvious body weight loss, and the liposomal TAS-103 is more active than free TAS-103[2].

CCRF-CEM human acute lymphoblastic leukaemia cells are grown in RPMI-1640 supplemented with 3 mM l-glutamine, 10% foetal bovine serum, 50 U/mL of penicillin, and 40 μg/mL of streptomycin at 37°C in a humidified atmosphere containing 5% CO2. TAS-103, CPT and DACA are dissolved in DMSO. Exponentially growing cells (～5 × 105) are exposed to either of the drugs for 2 hrs. Following drug exposure, cells are washed twice by centrifugation (400 × g, 3 min) in cold phosphate-buffered saline[1].