title: High effectiveness of platinum(IV) complex with adamantylamine in overcoming resistance to cisplatin and suppressing proliferation of ovarian cancer cells in vitro.
abstract: [(OC-6-43)-bis(acetato)(1-adamantylamine)amminedichloroplatinum(IV)], coded as LA-12, is an octahedral platinum(IV) complex containing a bulky hydrophobic ligand - adamantylamine. The use of bulky hydrophobic amines as non-leaving ligands, may increase uptake of the compound by the cancer cells. Therefore, the effects of LA-12 on sensitive (A2780) and cisplatin resistant (A2780cis) ovarian cancer cell lines were investigated and compared to those of cisplatin. IC(50) and IC(90) concentrations of LA-12 were 6- (A2780) or 18-fold (A2780cis) lower than those for cisplatin (MTT assay). Equitoxic concentrations (IC(50) or IC(90)) of both compounds caused a significant and similar time- and dose-dependent inhibition of cell proliferation and an increase in the number of floating cells which corresponded to the decrease of total cell viability. A different type and dynamics of cell cycle perturbation after cisplatin and LA-12 treatment were detected. Exposure to LA-12 resulted in transient accumulation of A2780 and A2780cis cells in S phase, while cisplatin caused G(2)/M arrest in sensitive and S phase arrest in resistant cells. A relatively low rate of apoptosis after exposure to IC(50) or IC(90) of both complexes was observed, markedly higher in resistant A2780cis cells. Western blot analysis indicated a concentration-dependent p53 level increase in both lines (higher after cisplatin treatment). PARP cleavage was observed only in A2780cis cells. In conclusion, LA-12 was found to be significantly more efficient than cisplatin, and it was able to overcome the acquired cisplatin resistance (showing resistance factor 2.84-fold lower than those for cisplatin). In spite of the low rate of apoptosis, LA-12 caused increase of p53 level and cell cycle perturbations in the ovarian cancer cell lines studied.
authors.affiliation: Laboratory of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic. kozubik@ibp.cz
authors.forename: Alois
authors.initials: A
authors.lastname: Kozubík
authors.forename: Viktor
authors.initials: V
authors.lastname: Horváth
authors.forename: Lenka
authors.initials: L
authors.lastname: Svihálková-Sindlerová
authors.forename: Karel
authors.initials: K
authors.lastname: Soucek
authors.forename: Jirina
authors.initials: J
authors.lastname: Hofmanová
authors.forename: Petr
authors.initials: P
authors.lastname: Sova
authors.forename: Ales
authors.initials: A
authors.lastname: Kroutil
authors.forename: Frantisek
authors.initials: F
authors.lastname: Zák
authors.forename: Adolf
authors.initials: A
authors.lastname: Mistr
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Turánek
mesh_terms: D000547:Amantadine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D053938:DNA Fragmentation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D009944:Organoplatinum Compounds / Q000494:pharmacology*; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011065:Poly(ADP-ribose) Polymerases / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D016159:Tumor Suppressor Protein p53; C482801:bis(acetato)(1-adamantylamine)amminedichloroplatinum(IV); D000547:Amantadine; D011065:Poly(ADP-ribose) Polymerases; D002945:Cisplatin