Antiproliferative activity of Pt(IV)-bis(carboxylato) conjugates on malignant pleural mesothelioma cells.
The bifunctional Pt(IV) conjugate cis,cis,trans-diamminedichloridobis(valproato)platinum(IV), based on the cisplatin square-plane with two axial valproato (2-propylpentanoate, VPA) ligands, has been re-synthesized with a modified procedure and its biological activity was compared with that of its isomer cis,cis,trans-diamminedichloridobis(n-octanoato)platinum(IV). Both complexes showed a striking cytotoxic effect (in the micro or sub-micromolar range) on various human carcinoma cell lines (namely ovarian, colon, breast and lung cancer), and, in particular, on cells derived from malignant pleural mesothelioma. This remarkable activity is due to the action of the cisplatin metabolite only, generated by the intracellular Pt(IV)→Pt(II) reduction, which concentration is greatly increased by the enhanced cellular accumulation of the original, highly lipophilic Pt(IV)-bis(carboxylato) complexes. The two axial VPA ligands are released in a too low concentration to act as histone deacetylase inhibitor (HDACI), as VPA works in the millimolar range, so that no synergism can be claimed. Moreover, n-octanoic acid is substantially deprived of any HDACI propensity.
Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale T. Michel 11, 15121 Alessandria, Italy.
Manuela
M
Alessio
Ilaria
I
Zanellato
Ilaria
I
Bonarrigo
Elisabetta
E
Gabano
Mauro
M
Ravera
Domenico
D
Osella
D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008654:Mesothelioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010984:Platinum / Q000737:chemistry / Q000494:pharmacology; D010997:Pleural Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
D000970:Antineoplastic Agents; D010984:Platinum
Drug delivery; Histone deacetylase inhibition; Platinum uptake; Pt(IV) complexes; Valproic acid