title: Desoxyepothilone B is curative against human tumor xenografts that are refractory to paclitaxel.
abstract: The epothilones are naturally occurring, cytotoxic macrolides that function through a paclitaxel (Taxol)-like mechanism. Although structurally dissimilar, both classes of molecules lead to the arrest of cell division and eventual cell death by stabilizing cellular microtubule assemblies. The epothilones differ in their ability to retain activity against multidrug-resistant (MDR) cell lines and tumors where paclitaxel fails. In the current account, we focus on the relationship between epothilone and paclitaxel in the context of tumors with multiple drug resistance. The epothilone analogue Z-12,13-desoxyepothilone B (dEpoB) is >35,000-fold more potent than paclitaxel in inhibiting cell growth in the MDR DC-3F/ADX cell line. Various formulations, routes, and schedules of i.v. administration of dEpoB have been tested in nude mice. Slow infusion with a Cremophor-ethanol vehicle proved to be the most beneficial in increasing efficacy and decreasing toxicity. Although dEpoB performed similarly to paclitaxel in sensitive tumors xenografts (MX-1 human mammary and HT-29 colon tumor), its effects were clearly superior against MDR tumors. When dEpoB was administered to nude mice bearing our MDR human lymphoblastic T cell leukemia (CCRF-CEM/paclitaxel), dEpoB demonstrated a full curative effect. For human mammary adenocarcinoma MCF-7/Adr cells refractory to paclitaxel, dEpoB reduced the established tumors, markedly suppressed tumor growth, and surpassed other commonly used chemotherapy drugs such as adriamycin, vinblastine, and etoposide in beneficial effects.
authors.affiliation: Molecular Pharmacology and Therapeutics Program, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10021, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Chou
authors.forename: X G
authors.initials: XG
authors.lastname: Zhang
authors.forename: C R
authors.initials: CR
authors.lastname: Harris
authors.forename: S D
authors.initials: SD
authors.lastname: Kuduk
authors.forename: A
authors.initials: A
authors.lastname: Balog
authors.forename: K A
authors.initials: KA
authors.lastname: Savin
authors.forename: J R
authors.initials: JR
authors.lastname: Bertino
authors.forename: S J
authors.initials: SJ
authors.lastname: Danishefsky
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use* / Q000633:toxicity; D001943:Breast Neoplasms / Q000188:drug therapy*; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D034261:Epothilones; D005260:Female; D006801:Humans; D007783:Lactones / Q000627:therapeutic use* / Q000633:toxicity; D007941:Leukemia P388; D015459:Leukemia-Lymphoma, Adult T-Cell; D051379:Mice; D008819:Mice, Nude; D010051:Ovarian Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000627:therapeutic use* / Q000633:toxicity; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000627:therapeutic use* / Q000633:toxicity; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D034261:Epothilones; D007783:Lactones; D013844:Thiazoles; D017239:Paclitaxel; C114026:desoxyepothilone B