title: MDR-related P170-glycoprotein modulates cytotoxic activity of homoharringtonine.
abstract: Homoharringtonine (HHT) is a new drug with antileukemic activity which is currently tested for treatment of acute and chronic leukemias, either alone or in combination with other agents. Since HHT showed a low efficacy in refractory and relapsed acute leukemia and in the blastic phase of chronic myeloid leukemia (CML) which are frequently characterized by an overexpresion of the multidrug resistance (MDR)-related P170-glycoprotein, we postulated a relationship between the poor antileukemic effect of HHT in these leukemias and the expression of P170-glycoprotein. For this reason, sensitive (LOVO109 and CEM) and MDR (LOVO DX and CEM VLB) cell lines were exposed to HHT with or without some MDR modifiers, namely, Cyclosporine A (CyA), the Cyclosporine derivative SDZ PSC 833 (PSC), and the D-isomer of Verapamil (DVRP). It was found that MDR cells were about 15 times more resistant to HHT than non-MDR cells, and that resistance to HHT was significantly decreased by all the MDR modifiers that were tested. This in vitro study showed that HHT belongs to the category of MDR-related drugs, like anthracyclines, vinca alkaloids, epipodophylline derivatives, and taxol.
authors.affiliation: Department of Medical and Morphologic Research, Udine University Hospital, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Russo
authors.forename: A
authors.initials: A
authors.lastname: Michelutti
authors.forename: C
authors.initials: C
authors.lastname: Melli
authors.forename: D
authors.initials: D
authors.lastname: Damiani
authors.forename: M G
authors.initials: MG
authors.lastname: Michieli
authors.forename: A
authors.initials: A
authors.lastname: Candoni
authors.forename: D C
authors.initials: DC
authors.lastname: Zhou
authors.forename: J P
authors.initials: JP
authors.lastname: Marie
authors.forename: R
authors.initials: R
authors.lastname: Zittoun
authors.forename: M
authors.initials: M
authors.lastname: Baccarani
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology*; D000230:Adenocarcinoma / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology; D003524:Cyclosporins / Q000494:pharmacology; D003630:Daunorubicin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000235:genetics; D005784:Gene Amplification; D006248:Harringtonines / Q000494:pharmacology*; D000077863:Homoharringtonine; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology; D009363:Neoplasm Proteins / Q000502:physiology*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D003524:Cyclosporins; D006248:Harringtonines; D009363:Neoplasm Proteins; D014747:Vinblastine; D000077863:Homoharringtonine; D004317:Doxorubicin; D014700:Verapamil; D003630:Daunorubicin