title: The hydrolysis of the anti-cancer ruthenium complex NAMI-A affects its DNA binding and antimetastatic activity: an NMR evaluation.
abstract: The coordination of the antimetastatic agent NAMI-A, [H(2)im][trans-RuCl(4)(dmso-S)(Him)], (Him=imidazole; dmso=dimethyl sulfoxide), to the DNA model base 9-methyladenine (9-MeAde) was investigated in water. NMR spectroscopy was first applied for the study of the molecular stability and hydrolysis of NAMI-A in aqueous solution over a range of pH (3.0-7.4) and chloride ion concentrations (0-1 M) at 37.0 degrees C. In physiological conditions (phosphate buffer, pH 7.4) NAMI-A disappears from the solution in 15 min due to chloride and dmso hydrolysis, leading to uncharacterised poly-oxo Ru species. Conversely, at lower pH (3.0-6.0) and in water (pH approximately 5.5), only a partial dmso hydrolysis occurs, slowly forming the [trans-RuCl(4)(H(2)O)(Him)](-) complex. This latter species coordinates to 9-MeAde (via the N7 of 9-MeAde), forming the [trans-RuCl(4)(9-MeAde)(Him)](-) complex. NAMI-A and [trans-RuCl(4)(H(2)O)(Him)](-) give comparable intracellular ruthenium concentrations and accumulate in KB cells (human mouth carcinoma) and accumulate these at the G(2)/M phase, while poly-oxo Ru species do not, and their cell uptake is reduced to 50%. On the contrary, G(2)/M arrest and protein content in the murine metastatic cell line metGM, are not influenced by NAMI-A hydrolysis. Hydrolysed NAMI-A species apparently are easier taken up by the metGM cells, showing intracellular ruthenium concentrations one order of magnitude greater than those of intact NAMI-A. Therefore, it is proposed that the selective antimetastatic activity of NAMI-A during in vivo experiments can be attributed to its hydrolysed species.
authors.affiliation: Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Marina
authors.initials: M
authors.lastname: Bacac
authors.forename: Anna C G
authors.initials: AC
authors.lastname: Hotze
authors.forename: Karlijn
authors.initials: K
authors.lastname: van der Schilden
authors.forename: Jaap G
authors.initials: JG
authors.lastname: Haasnoot
authors.forename: Sabrina
authors.initials: S
authors.lastname: Pacor
authors.forename: Enzo
authors.initials: E
authors.lastname: Alessio
authors.forename: Gianni
authors.initials: G
authors.lastname: Sava
authors.forename: Jan
authors.initials: J
authors.lastname: Reedijk
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D002453:Cell Cycle; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002712:Chlorides / Q000502:physiology; D004273:DNA, Neoplasm / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009362:Neoplasm Metastasis; D009942:Organometallic Compounds / Q000378:metabolism* / Q000494:pharmacology*; D012428:Ruthenium / Q000737:chemistry / Q000378:metabolism; D017975:Ruthenium Compounds; D014867:Water / Q000502:physiology
chemical_list: D000970:Antineoplastic Agents; D002712:Chlorides; D004273:DNA, Neoplasm; D007093:Imidazoles; D009942:Organometallic Compounds; D017975:Ruthenium Compounds; C113661:imidazolium-bis(imidazole)dimethylsulfoxideimidazotetrachlororuthenate(III); D014867:Water; D012428:Ruthenium; D004121:Dimethyl Sulfoxide