title: Docetaxel enhances the cytotoxicity of anthracyclines by increasing intracellular drug accumulation.
abstract: We assessed the combined antitumor activity of docetaxel and doxorubicin (DXR) and tetrahydropyranyl-adriamycin (THP) using the human breast carcinoma cell lines R-27 and MDA-MB-231. Synergistic antitumor activity was observed for both combined docetaxel and DXR, and docetaxel and THP against R-27 cells when contacted simultaneously. However, only additive effects were observed against MDA-MB-231 cells. Intracellular concentrations of DXR and THP in R-27 cells were significantly increased by docetaxel pretreatment, however, this increase was not observed in MDA-MB-231 cells, which exhibited only additive sensitivity to the treatment. Thus, docetaxel increased the antitumor activity of anthracyclines by increasing their intracellular concentrations.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, Tokyo 160-8582, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Egawa
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kubota
authors.forename: Akihiko
authors.initials: A
authors.lastname: Suto
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Otani
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Furukawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kumai
authors.forename: Masaki
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000188:drug therapy*; D002455:Cell Division / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D000077143:Docetaxel; D004317:Doxorubicin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D017239:Paclitaxel / Q000008:administration & dosage / Q000031:analogs & derivatives*; D043823:Taxoids; D014407:Tumor Cells, Cultured / Q000187:drug effects*
chemical_list: D043823:Taxoids; D000077143:Docetaxel; D004317:Doxorubicin; C027260:pirarubicin; D017239:Paclitaxel