title: In vitro and in vivo evaluation of WK-X-34, a novel inhibitor of P-glycoprotein and BCRP, using radio imaging techniques.
abstract: Overexpression of the multidrug resistance proteins P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) results in treatment failure of many malignancies including ovarian cancer. Dual inhibition of Pgp and BCRP may restore the sensitivity of resistant cells to anticancer drugs. We report the synthesis and characterization of a novel anthranilic-acid based Pgp and BCRP modulator, WK-X-34. In vitro inhibition of Pgp activity was evaluated using 99mTc-Sestamibi and daunorubicin accumulation in Pgp overexpressing human ovarian cancer cells (A2780/Adr) and its sensitive counterpart (A2780/wt). Interaction with BCRP was examined with a mitoxantrone-efflux assay in BCRP-overexpressing MCF7/mx cells, with flow cytometry. Interactions with the multidrug resistance associated proteins (MRP) were evaluated in transfected MRP1, MRP2 and MRP3 cell lines, using a 5-CFDA efflux assay. In vivo 99mTc-Sestamibi imaging of human ovarian cancer xenografts was used to evaluate the in vivo efficacy of WK-X-34 in mice. Daunorubicin accumulation in A2780/Adr cells was inhibited by WK-X-34 at nanomolar concentrations (IC50: 82.1 +/- 6 nM). WK-X-34 inhibited mitoxantrone accumulation in BCRP-overexpressing cells at micromolar concentrations (IC50 = 26.5 +/- 4.6 microM), whereas WK-X-34 did not significantly alter 5-CFDA accumulation in MRP transfected cells. In vivo, uptake of 99mTc-Sestamibi was significantly increased in A2780/Adr xenograft tumors, brain and intestine (AUCs(0-4h) 136%, 147% and 138%; p < 0.05) in mice dosed with WK-X-34 (20 mg/kg i.p.). WK-X-34 selectively modulates Pgp and BCRP in vitro and in vivo in multidrug resistant ovarian cancer cells, and thus may have potential utility in the treatment of multidrug resistant tumors.
authors.affiliation: Pharmaceutical Institute, University of Bonn, Bonn, Germany.
authors.forename: Veronika
authors.initials: V
authors.lastname: Jekerle
authors.forename: Werner
authors.initials: W
authors.lastname: Klinkhammer
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Scollard
authors.forename: Kerstin
authors.initials: K
authors.lastname: Breitbach
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Reilly
authors.forename: Micheline
authors.initials: M
authors.lastname: Piquette-Miller
authors.forename: Michael
authors.initials: M
authors.lastname: Wiese
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D019540:Area Under Curve; D001549:Benzamides / Q000008:administration & dosage / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003630:Daunorubicin / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D005434:Flow Cytometry; D005453:Fluorescence; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008942:Mitoxantrone / Q000378:metabolism; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000187:drug effects* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000378:metabolism*; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D013997:Time Factors; D014018:Tissue Distribution; D014183:Transplantation, Heterologous; D015854:Up-Regulation
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D001549:Benzamides; D003630:Daunorubicin; D008942:Mitoxantrone; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; C116614:ABCG2 protein, human; C511688:WK-X-34; C114462:multidrug resistance-associated protein 3; C421109:multidrug resistance-associated protein 1