title: Modulation of sensitivity to cis-diamminedichloroplatinum (II) by thromboxane A2 receptor antagonists in non-small-cell lung cancer cell lines.
abstract: We examined the effect of selective thromboxane A2 (TXA2) receptor antagonists, calcium 5(Z)-1R, 2S, 3S, 4S-7-[3-phenylsulphonylaminobicyclo [2.2.1] hept-2-yl]-5-heptonoate hydrate (S-1452) and +/- -7-(3,5,6,-trimethyl-1,4-benzoquinon-2-yl)-7-phenylhaptanoic acid (AA-2414), on sensitivity to cis-diamminedichloroplatinum (II) (CDDP) in non-small-cell lung cancer cell lines. IC50 values to CDDP using MTT assay were decreased 2.1- and 4.6-fold respectively by treatment with 250 or 500 microM S-1452, for a 2 h simultaneous drug exposure, and those of PC-9/CDDP, a CDDP-resistant cell line, were decreased 3.1- and 6.1-fold. Sensitivity to carboplatin was also enhanced by the treatment with S-1452. IC50 values to CDDP and carboplatin were decreased by treatment with AA-2414 in a dose-dependent manner. Isobologram analysis showed that the combination of CDDP with S-1452 or AA-2414 produced supra-additive or additive effects in each cell line. Neither glutathione content nor glutathione S-transferase activity was changed in either cell line by treatment with 500 microM S-1452. Accumulation of platinum into PC-9 and PC-9/CDDP was increased by the treatment in a dose-dependent manner. Na+, K+-ATPase activity of PC-9 and PC-9/CDDP was enhanced by the treatment of S-1452 in a dose-dependent manner. These data show that the TXA2 receptor antagonists may enhance the sensitivity of non-small-cell lung cancer cell lines to platinum agents. Increase in Na+, K+-ATPase activity induced by S-1452 may be the mechanism of its sensitising effect through increase in platinum accumulation.
authors.affiliation: The Third Department of Internal Medicine, Kanazawa University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kasahara
authors.forename: M
authors.initials: M
authors.lastname: Fujimura
authors.forename: T
authors.initials: T
authors.lastname: Bando
authors.forename: K
authors.initials: K
authors.lastname: Shibata
authors.forename: H
authors.initials: H
authors.lastname: Shirasaki
authors.forename: T
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy*; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D016227:Benzoquinones / Q000494:pharmacology*; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy*; D002945:Cisplatin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology*; D006538:Heptanoic Acids / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy*; D011448:Prostaglandin Antagonists / Q000494:pharmacology*; D017482:Receptors, Thromboxane / Q000037:antagonists & inhibitors*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D016227:Benzoquinones; D001643:Bridged Bicyclo Compounds; D005229:Fatty Acids, Monounsaturated; D006538:Heptanoic Acids; D011448:Prostaglandin Antagonists; D017482:Receptors, Thromboxane; D013778:Tetrazolium Salts; D013844:Thiazoles; C056566:S 145; C060230:seratrodast; C022616:thiazolyl blue; D002945:Cisplatin