title: ABCB1-overexpressing MDCK-II cells are hypersensitive to 3-bromopyruvic acid.
abstract: OBJECTIVE
  Cancer cells, due to the Warburg effect, are more dependent on glycolysis than normal cells, so glycolytic inhibitor 3-bromopyruvic acid (3-BP) was proposed as a promising candidate for anticancer therapy. Overexpression of multidrug transporters is the main reason of resistance of cancer cells to chemotherapy. As the activity of multidrug transporters imposes an energetic burden on the cells, it can be expected that inhibition of ATP generation may exert a selective cytotoxicity to cells overexpressing multidrug transporters. The aim of this study was to compare the effect of 3-BP on the survival and ATP level in MDCK-II cells and MDCK-II cells overexpressing ABCB1 (Pgp) or ABCG2 (BCRP).
  
  
  METHODS
  Cell survival was measured with resazurin and with neutral red. ATP level was assayed with luciferin/luciferase kit. Luteolin transport was measured by an original method described in the paper.
  
  
  RESULTS
  3-BP (10-200μM) induced a decrease of ATP level after 1-h incubation in all cell lines studied, more drastically in ABCB1-overexpressing cells. 50 and 200μM 3-BP significantly decreased cell viability; the effect was more pronounced for ABCB1-overexpressing cells. PSC833, inhibitor of ABCB1, ameliorated the toxic effect of 3-BP on MDCK-II ABCB1 cells and MDCK-II cells. 3-BP inhibited luteolin transport in MDCK-II ABCG2 cells.
  
  
  CONCLUSIONS
  These results indicate that 3-BP shows selective toxicity against ABCB1- but not ABCG2-overexpressing cells, apparently due to enhanced ATP depletion but in a manner independent of the transport activity of Pgp, suggesting a novel mechanism of hypersensitivity of ABCB1-overexpressing cells to 3-BP.
authors.affiliation: Department of Biochemistry and Cell Biology, Faculty of Biology and Agriculture, University of Rzeszów, Zelwerowicza 4, 35-601 Rzeszów, Poland. Electronic address: isadowska@poczta.fm.
authors.forename: Izabela
authors.initials: I
authors.lastname: Sadowska-Bartosz
authors.affiliation: Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Grębowski
authors.affiliation: Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kępka
authors.affiliation: Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Studzian
authors.affiliation: Department of Biochemistry and Cell Biology, Faculty of Biology and Agriculture, University of Rzeszów, Zelwerowicza 4, 35-601 Rzeszów, Poland; Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bartosz
authors.affiliation: Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; Laboratory of Transcriptional Regulation, Institute of Medical Biology of the Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Pułaski
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000818:Animals; D004285:Dogs; D061985:Madin Darby Canine Kidney Cells; D011773:Pyruvates / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D011773:Pyruvates; C017092:bromopyruvate
keywords: 3-Bromopyruvate; ABCB1 protein; ABCG2 protein; ATP; MDKC-II cells; Multidrug resistance