title: Tetramethylpiperidine-substitution increases the antitumor activity of the riminophenazines for an acquired multidrug-resistant cell line.
abstract: The multidrug resistance (MDR)-neutralizing and cytotoxic properties of five tetramethylpiperidine (TMP)-substituted phenazines were compared with those of their corresponding isopropyl-substituted analogues using a P-glycoprotein (P-gp)-expressing small cell lung cancer cell line (H69/LX4). All of the TMP-substituted phenazines tested outperformed their isopropyl analogues with respect to both cytotoxic and chemosensitizing properties, indicating the importance of TMP-substitution when designing novel riminophenazines with increased activity against MDR cancer cell lines. Of the TMP-substituted phenazines tested, B4112, chlorinated at position 3 of the phenyl- and anilino-rings, had the most potent anti-cancer activity in vitro, making this agent a potential candidate for evaluation in experimental and clinical oncology.
authors.affiliation: Department of Immunology, Institute for Pathology, University of Pretoria, South Africa.
authors.forename: C E
authors.initials: CE
authors.lastname: van Rensburg
authors.forename: G K
authors.initials: GK
authors.lastname: Jooné
authors.forename: J F
authors.initials: JF
authors.lastname: O'Sullivan
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000378:metabolism; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D018288:Carcinoma, Small Cell / Q000188:drug therapy / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D020128:Inhibitory Concentration 50; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism; D010619:Phenazines / Q000138:chemical synthesis / Q000494:pharmacology*; D010880:Piperidines / Q000138:chemical synthesis / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D010619:Phenazines; D010880:Piperidines; D014747:Vinblastine