title: Oleanolic acid derivative methyl 3,11-dioxoolean-12-en-28-olate targets multidrug resistance related to ABCB1.
abstract: Multidrug resistance (MDR) in leukemia patients is a great  incentive to the development of new drugs. In a search for potential multidrug resistance modulators we tested a group of oleanolic acid (OA) analogues modified at C-3, C-11, C-12 and C-28 using an experimental model consisting of three human acute lymphoblastic leukemia cell lines (CCRF-CEM and the multidrug resistant sublines CCRF-VCR1000 and CCRF-ADR5000). The most effective compound, methyl 3,11-dioxoolean-12-en-28-olate (DIOXOL) was more potent in cell viability inhibition than its precursor - OA, and showed similar or even higher activity in the drug resistant than in the wild-type cells. Resistance factor (RF) values obtained for CCRF-VCR1000 and CCRF-ADR-5000 cells using MTT assay were 0.7 and 0.8 (24 h of treatment) and after 72 h of treatment 0.9 and 1.1, respectively. Moreover, 5 μM DIOXOL significantly reduced the expression of the ABCB1 gene in MDR cells by around 30%, and also decreased the level of P-gp protein. Compared to untreated control cells, DIOXOL treatment resulted in a significant P-gp decrease (30% in CCRF-ADR5000 and 50% in CCRF-VCR1000), that was detected by western blot and confirmed by flow cytometry analysis. Moreover, DIOXOL (at 10 μM) significantly inhibited P-gp transport function by more than twofold comparing to control, untreated cells that was demonstrated using rhodamine 123-based functional test. The compound exhibited synergistic activity with ABCB1 substrate - adriamycin in CCRF-VCR1000 cells, indicating partial but significant MDR reversing ability.
authors.affiliation: Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, Przybyszewskiego 49, PL 60-355 Poznań, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Paszel
authors.forename: Błażej
authors.initials: B
authors.lastname: Rubiś
authors.forename: Barbara
authors.initials: B
authors.lastname: Bednarczyk-Cwynar
authors.forename: Lucjusz
authors.initials: L
authors.lastname: Zaprutko
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kaczmarek
authors.forename: Johann
authors.initials: J
authors.lastname: Hofmann
authors.forename: Maria
authors.initials: M
authors.lastname: Rybczyńska
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004148:Dioxolanes / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D016503:Drug Delivery Systems / Q000379:methods*; D018432:Drug Resistance, Multiple / Q000187:drug effects* / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D009828:Oleanolic Acid / Q000008:administration & dosage* / Q000031:analogs & derivatives*
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004148:Dioxolanes; D009828:Oleanolic Acid