Development and biological investigations of hypoxia-sensitive prodrugs of the tyrosine kinase inhibitor crizotinib.
Bjoern Bielec, Hemma Schueffl, Alessio Terenzi, Walter Berger, Petra Heffeter, Bernhard K Keppler, Christian R Kowol
Author Information
Bjoern Bielec: Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, 1090 Vienna, Austria.
Hemma Schueffl: Institute of Cancer Research, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria.
Alessio Terenzi: Donostia International Physics Center, Paseo Manuel de Lardizabal 4, Donostia 20018, Spain.
Walter Berger: Institute of Cancer Research, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria; Research Cluster ''Translational Cancer Therapy Research'', Vienna, Austria.
Petra Heffeter: Institute of Cancer Research, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria; Research Cluster ''Translational Cancer Therapy Research'', Vienna, Austria. Electronic address: petra.heffeter@meduniwien.ac.at.
Bernhard K Keppler: Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, 1090 Vienna, Austria; Research Cluster ''Translational Cancer Therapy Research'', Vienna, Austria.
Christian R Kowol: Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, 1090 Vienna, Austria; Research Cluster ''Translational Cancer Therapy Research'', Vienna, Austria. Electronic address: christian.kowol@univie.ac.at.
Despite the huge success of tyrosine kinase inhibitors as anticancer agents, severe side effects are a major problem. In order to overcome this drawback, the first hypoxia-activatable 2-nitroimidazole-based prodrugs of the clinically approved ALK and c-MET inhibitor crizotinib were developed. The 2-aminopyridine functionality of crizotinib (essential for target kinase binding) was considered as ideal position for prodrug derivatization. Consequently, two different prodrugs were synthesized with the nitroimidazole unit attached to crizotinib either via carbamoylation (A) or alkylation (B) of the 2-aminopyridine moiety. The successful prodrug design could be proven by docking studies and a dramatically reduced ALK and c-MET kinase-inhibitory potential. Furthermore, the prodrugs showed high stability in serum and release of crizotinib in an enzymatic nitroreductase-based cleavage assay was observed for prodrug A. The in vitro activity of both prodrugs was investigated against ALK- and c-MET-dependent or -overexpressing cells, revealing a distinct hypoxia-dependent activation for prodrug A. Finally, inhibition of c-MET phosphorylation and cell proliferation could also be proven in vivo. In summary of the theoretical, chemical and biological studies, prodrug derivatization of the 2-aminopyridine position can be considered as a promising strategy to reduce the side effects and improve the anticancer activity of crizotinib.
