title: Prevention of MDR development in leukemia cells by micelle-forming polymeric surfactant.
abstract: Doxorubicin (Dox) incorporated in nanosized polymeric micelles, SP1049C, has shown promise as monotherapy in patients with advanced esophageal carcinoma. The formulation contains amphiphilic block copolymers, Pluronics, that exhibit the unique ability to chemosensitize multidrug resistant (MDR) tumors by inhibiting P-glycoprotein (Pgp) drug efflux system and enhancing pro-apoptotic signaling in cancer cells. This work evaluates whether a representative block copolymer, Pluronic P85 (P85) can also prevent development of Dox-induced MDR in leukemia cells. For in vitro studies murine lymphocytic leukemia cells (P388) were exposed to increasing concentrations of Dox with/without P85. For in vivo studies, BDF1 mice bearing P388 ascite were treated with Dox or Dox/P85. The selected P388 cell sublines and ascitic tumor-derived cells were characterized for Pgp expression and functional activity (RT-PCR, Western Blot, rhodamine 123 accumulation) as well as Dox resistance (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay). The global gene expression was determined by oligonucleotide gene microarrays. We demonstrated that P85 prevented development of MDR1 phenotype in leukemia cells in vitro and in vivo as determined by Pgp expression and functional assays of the selected cells. Cells selected with Dox in the presence of P85 in vitro and in vivo exhibited some increases in IC(50) values compared to parental cells, but these values were much less than IC(50) in respective cells selected with the drug alone. In addition to mdr1, P85 abolished alterations of genes implicated in apoptosis, drug metabolism, stress response, molecular transport and tumorigenesis. In conclusion, Pluronic formulation can prevent development of MDR in leukemia cells in vitro and in vivo.
authors: Center for Drug Delivery and Nanomedicine, Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, USA.
authors: Amit K
authors: AK
authors: Sharma
authors: Li
authors: L
authors: Zhang
authors: Shu
authors: S
authors: Li
authors: David L
authors: DL
authors: Kelly
authors: Valery Yu
authors: VY
authors: Alakhov
authors: Elena V
authors: EV
authors: Batrakova
authors: Alexander V
authors: AV
authors: Kabanov
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D019450:Genes, MDR; D020128:Inhibitory Concentration 50; D007941:Leukemia P388; D051379:Mice; D008815:Mice, Inbred Strains; D008823:Micelles; D011060:Poloxalene / Q000494:pharmacology*; D020112:Rhodamine 123 / Q000378:metabolism; D013501:Surface-Active Agents / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D005456:Fluorescent Dyes; D008823:Micelles; D013501:Surface-Active Agents; C422648:pluronic block copolymer p85; D020112:Rhodamine 123; D004317:Doxorubicin; D011060:Poloxalene