Multi-action cisplatin-based mono- (1) and di-clofibric acid (2) Pt(IV) “combo” derivatives were synthesized via both traditional and microwave assisted procedures. The two complexes offered very good performances (IC50 values in a nanomolar range) on a panel of human tumor cell lines, including the highly chemoresistant malignant pleural mesothelioma ones. Moreover, both 1 and 2 bypass the cisplatin resistance. Indeed, cisplatin and clofibric acid, the metabolites of the Pt(IV) → Pt(II) intracellular reduction, proved to act synergistically. The adjuvant action of clofibric acid relies on the activation of peroxisome proliferator-activated receptor α (PPARα) that, in turn, decreases the level of Hypoxia-Inducible Factor-1α. Both compounds induced extensive apoptosis in tumor cells, also via oxidative stress. Finally, 2 exhibited excellent performances also under the hypoxic conditions typical of solid tumors, where cisplatin is less effective.
