RESUMO
The reactions of cyclopropylamine, cyclopentylamine, and cyclohexylamine with trans-[PtCl2(NCMe)2] afforded the bis-cationic complexes trans-[Pt(amine)2(Z-amidine)2]2+[Cl-]2, 1-3. The solution behavior and biological activity have been studied in different solvents (DMSO, water, polyethylene glycol (PEG 400), and polyethylene glycol dimethyl ether (PEG-DME 500)). The biological activity was strongly influenced by the cycloaliphatic amine ring size, with trans-[Pt(NH2CH(CH2)4CH2)2{N(H) horizontal lineC(CH3)N(H)CH(CH2)4CH2}2]2+[Cl-]2 (3) being the most active compound. Complex 3 overcame both cisplatin and MDR resistance, inducing cancer cell death through p53-mediated apoptosis. Alkaline single-cell gel electrophoresis experiments indicated direct DNA damage, reasonably attributable to DNA adducts of trans-[PtCl(amine)(Z-amidine)2][Cl] species, which can evolve to produce disruptive and nonrepairable lesions on DNA, thus leading to the drug-induced programmed cancer cell death. Preliminary in vivo antitumor studies on C57BL mice bearing Lewis lung carcinoma highlighted that complex 3 promoted a significant and dose-dependent tumor growth inhibition without adverse side effects.
Assuntos
Amidinas/síntese química , Aminas/síntese química , Antineoplásicos/síntese química , Complexos de Coordenação/síntese química , Platina , Amidinas/química , Amidinas/farmacologia , Aminas/química , Aminas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Cristalografia por Raios X , Dano ao DNA/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Solubilidade , Estereoisomerismo , Relação Estrutura-Atividade , Proteína Supressora de Tumor p53/biossínteseRESUMO
New substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-R}(2)] (R=Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the (1)H NMR data. Complex trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes 1a and 5a showed IC(50) values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug.
