title: [In vitro characterization of S9788, a new modulator of multidrug resistance].
abstract: S9788, a new triazinoaminopiperidine derivative, was 250-fold more active than verapamil in sensitizing DC-3F/AD cells to actinomycin D. This multidrug-resistance modulating activity of S9788 was confirmed on DC-3F/AD, P388/ADR-10, P388/VCR-20, KB/A1, K562/R, S1/tMDR, and COLO320DM cells, with respect to actinomycin D, doxorubicin, vincristine, vinblastine and etoposide. S9788 is 2-255-fold more active than verapamil, depending on the cell line and the cytotoxic agent used, potentiating preferentially the cytotoxicity of the vinca-alkaloid derivatives. S9788 only had a slight effect on vincristine accumulation and retention by parental sensitive cells, as well as on their sensitivity to cytotoxic drugs. S9788 fully restored vincristine accumulation and retention by S1/tMDR cells (S1 cells transfected by the mdr 1 gene) to a level similar to that measured in S1 cells, leading to a blockade in the G2 + M phase of the cell cycle. Therefore, S9788 enhances vincristine activity by restoring its cellular accumulation in resistant cells. After a short incubation period of cells with vincristine (4 h), a condition close to the clinical administration of this cytotoxic agent, a post-incubation for 20 hours more with 5 microM S9788, fully restored the sensitivity of S1/tMDR cells to vincristine. After an exposure of 4 hours at equal concentrations, the accumulation of S9788 was 13-fold that of verapamil in S1/tMDR cells, and 20 hours after the removal of the modulators, S9788 was retained at a concentration 20-fold that of verapamil. S9788 is therefore a powerful new modifier of the P-gp-mediated multidrug-resistance, which by its pharmacological properties (cellular kinetics and activity), might be used in combination with existing chemotherapy against tumors displaying the MDR phenotype.
authors.affiliation: Division de cancérologie expérimentale, institut de recherches Servier, Suresnes, France.
authors.forename: V
authors.initials: V
authors.lastname: Pérez
authors.forename: A
authors.initials: A
authors.lastname: Pierré
authors.forename: S
authors.initials: S
authors.lastname: Léonce
authors.forename: M
authors.initials: M
authors.lastname: Anstett
authors.forename: J F
authors.initials: JF
authors.lastname: Prost
authors.forename: G
authors.initials: G
authors.lastname: Atassi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D004351:Drug Resistance / Q000235:genetics; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy*; D009374:Neoplasms, Experimental / Q000188:drug therapy; D010641:Phenotype; D010880:Piperidines / Q000494:pharmacology*; D014227:Triazines / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D010880:Piperidines; D014227:Triazines; C077022:S 9788; D014700:Verapamil
vernacular_title: Caractérisation in vitro de l'activité du S9788, un nouveau modulateur de la résistance multidrogue.