RESUMEN
Two new p-cresol-2,6-bis(amide-tether-dpa4-X) ligands (HL4-X, X = MeO and Cl) and their dicopper complexes [Cu2(µ-1,1-OAc)(µ-1,3-OAc)(L4-MeO)]Y (Y = PF6 1a, OAc 1b) and [Cu2(µ-1,3-OAc)2(L4-Cl)]Y (Y = ClO4 2a, OAc 2b) were synthesized. The electronic and hydrophobic effects of the MeO and Cl groups were examined compared with nonsubstituted complex [Cu2(µ-1,1-OAc)(µ-1,3-OAc)(L)]+ (3). The electronic effects were found in crystal structures, spectroscopic characterization, and redox potentials of these complexes. 1b and 2b were reduced to Cu(I)Cu(I) with sodium ascorbate and reductively activated O2 to produce H2O2 and HOâ¢. The H2O2 release and HO⢠generation are promoted by the electronic effects. The hydrophobic effects increased the lipophilicity of 1b and 2b. Cellular ROS generation of 1b, 2b, and 3 was visualized by DCFH-DA. To examine the intracellular behavior, boron dipyrromethene (Bodipy)-modified complexes 4B and 5B corresponding to 1b and 2b were synthesized. These support that 1b and 2b are localized at the ER and Golgi apparatus. The cytotoxicity of 1b and 2b against various cell lines was examined by MTT assay. 1b and 2b were 7- and 41-fold more cytotoxic than 3. 1b generated ROS selectively in cancer cell but 2b nonselectively in cancer and normal cells, causing cancer- and normal-cell-selective cytotoxicity, respectively.
Asunto(s)
Antineoplásicos , Complejos de Coordinación , Cobre , Interacciones Hidrofóbicas e Hidrofílicas , Especies Reactivas de Oxígeno , Humanos , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Especies Reactivas de Oxígeno/metabolismo , Cobre/química , Cobre/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Estructura Molecular , Cresoles/química , Cresoles/farmacología , Cresoles/síntesis química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Electrones , Amidas/química , Amidas/farmacología , Amidas/síntesis químicaRESUMEN
Dicopper complexes [Cu2(µ-OH)(Ln)](ClO4)2 [n = 1 (1) and 2 (2)] with a novel phenanthrene amide-tether ligand conjugate (HL1) and the original p-cresol-2,6-bis(amidecyclen) (HL2) were synthesized. A phenanthrene unit of 1 enhances the DNA-binding by 9-fold, enabling 1 to convert supercoiled plasmid DNA with H2O2 to a linear one in a 9.3-fold higher yield than 2. 1 reacts with H2O2 to form the µ-1,1-hydroperoxodicopper(II) complex 3 as the active species. The IC50 values of 1 against cancer cells of the lung and pancreas are 23.8 and 18.4 µM, respectively, 12-fold more toxic than the 284 and 241 µM of 2. Confocal microscopy, fluorescence-activated cell sorting, and caspase activity assays using HeLa cells revealed that 1 induces mitochondrial apoptosis. A DNA-targeting phenanthrene unit of 1 enhances the cancer-cell-selective toxicity via mitochondrial apoptosis.
Asunto(s)
Amidas/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Complejos de Coordinación/farmacología , Cobre/farmacología , Mitocondrias/efectos de los fármacos , Fenantrenos/farmacología , Amidas/química , Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Complejos de Coordinación/química , Cobre/química , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ligandos , Fenantrenos/química , Células Tumorales CultivadasRESUMEN
Dicopper complexes of a new p-cresol-2,6-bis(dpa) amide-tether ligand (HL1), [Cu2(µ-OH2)(µ-1,3-OAc)(L1)](ClO4)2 (1) and [Cu2(µ-1,1-OAc)(µ-1,3-OAc)(L1)]X (X = ClO4 (2a), OAc (2b)) were synthesized and structurally characterized. 2b rapidly cleaves supercoiled plasmid DNA by activating H2O2 at neutral pH to a linear DNA and shows remarkable cytotoxicity in comparison with related complexes. As 2b is more cytotoxic than HL1, the dicopper core is kept in the cell. A boron dipyrromethene (Bodipy)-modified complex of the p-cresol-2,6-bis(dpa) amide-tether ligand having a Bodipy pendant (HL2), [Cu2(µ-OAc)2(L2)](OAc) (3), was synthesized to visualize intracellular behavior, suggesting that 2b attacks the nucleolus and mitochondria. A comet assay clearly shows that 2b does not cleave nuclear DNA. The apoptotic cell death is evidenced from flow cytometry.
Asunto(s)
Amidas/farmacología , Antineoplásicos/farmacología , Complejos de Coordinación/farmacología , Cobre/farmacología , Cresoles/farmacología , ADN/efectos de los fármacos , Amidas/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Cobre/química , Cresoles/química , División del ADN , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Peróxido de Hidrógeno/antagonistas & inhibidores , Peróxido de Hidrógeno/farmacología , Ligandos , Estructura Molecular , Imagen Óptica , Oxidación-Reducción , PlásmidosRESUMEN
Metal complexes to promote oxidative DNA cleavage by H2O2 are desirable as anticancer drugs. A dicopper(II) complex of known p-cresol-derived methylene-tether ligand Hbcc [Cu2(bcc)]3+ did not promote DNA cleavage by H2O2. Here, we synthesized a new p-cresol-derived amide-tether one, 2,6-bis(1,4,7,10-tetrazacyclododecyl-1-carboxyamide)-p-cresol (Hbcamide). A dicopper(II) complex of the new ligand [Cu2(µ-OH)(bcamide)]2+ was structurally characterized. This complex promoted the oxidative cleavage of supercoiled plasmid pUC19 DNA (Form I) with H2O2 at pH 6.0-8.2 to give Forms II and III. The reaction was largely accelerated in a high pH region. A µ-1,1-hydroperoxo species was formed as the active species and spectroscopically identified. The amide-tether complex is more effective in cytotoxicity against HeLa cells than the methylene-tether one.