title: Docetaxel enhances the cytotoxicity of tetrahydropyranyladriamycin in a sequence-dependent manner.
abstract: BACKGROUND
  Taxanes and anthracyclines are active against breast cancer. In this study we investigated the combined antitumor activity of these drugs, with particular regard to sequence-dependency.
  
  
  METHODS
  The combined antitumor activity of docetaxel and tetrahydropyranyladriamycin (THP) against two human breast cancer xenografts was assessed using an in vitro histoculture drug-response assay. The sequence-dependency of the combined cytotoxicity was evaluated by isobologram.
  
  
  RESULTS
  A synergistic antitumor activity of combined docetaxel + THP was exhibited against the R-27 xenograft when docetaxel was given first or simultaneously with THP. However, this synergism was diminished when THP was used before docetaxel. While an additive effect of combined docetaxel + THP was observed against MX-1 xenograft when docetaxel was given first or simultaneously with THP, this effect was not marked using the THP/docetaxel sequence.
  
  
  CONCLUSIONS
  Docetaxel increased the antitumor activity of THP, but only when administered before or simultaneously with THP.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Egawa
authors.forename: T
authors.initials: T
authors.lastname: Kubota
authors.forename: T
authors.initials: T
authors.lastname: Furukawa
authors.forename: Y
authors.initials: Y
authors.lastname: Otani
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Furukawa
authors.forename: K
authors.initials: K
authors.lastname: Kumai
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D000328:Adult; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000188:drug therapy*; D000077143:Docetaxel; D004317:Doxorubicin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004334:Drug Administration Schedule; D004357:Drug Synergism; D005260:Female; D006801:Humans; D020128:Inhibitory Concentration 50; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy*; D051379:Mice; D008819:Mice, Nude; D017239:Paclitaxel / Q000008:administration & dosage / Q000031:analogs & derivatives*; D043823:Taxoids; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D043823:Taxoids; D000077143:Docetaxel; D004317:Doxorubicin; C027260:pirarubicin; D017239:Paclitaxel