[Effects of SN-38 in combination with other anticancer agents against Dauji cells]

To investigate the effects of CPT-11 in combination with other anticancer agents, a human Burkitt's lymphoma cell line, Dauji, was incubated for 3 days in the presence of SN-38 (active substance of CPT-11) and the combined drug and cell growth inhibition was determined by MTT assay. The effects of the drug combinations at ID50 were then analyzed by isobologram (Steel and Peckham). A supra-additive (synergistic) effect was observed for SN-38 in combination with carboplatin, cisplatin, cytosine arabinoside, and mitomycin C. An additive effect was observed for its combination with bleomycin, etoposide, 5-fluorouracil, and mitoxantrone. Additive and sub-additive (antagonistic) effects were observed in combination with doxorubicin. A Sub-additive effect was observed in combination with methotrexate and vincristine.