Enhancement of Antiangiogenic Efficacy of Iron(II) Complex by Selenium Substitution.

Antiangiogenesis therapy is a proven strategy for the treatment of cancers. Herein, we demonstrate that iron(II) complexes containing 1,10-phenanthroline(phen) derivatives were capable of suppressing angiogenesis in vitro in a dose-dependent manner. Interestingly, the introduction of selenium into an iron(II) complex ((Fe(phenSe)3 (ClO4 )2 (phenSe=2-selenoimidazole[4,5-f]1,10-phenanthroline)) could enhance its antiangiogenic efficacy. Mechanistic studies demonstrated that the complex potently induced endothelial cell apoptosis as evidenced by activation of caspases and PARP cleavage. The iron(II) complex activated p53-mediated mitochondrial dysfunction as can be seen by the upregulation in the expression of p53 and proapoptotic Bcl-2 family proteins, and downregulation in the expression of Bcl-2 family proteins. Additionally, the complex inhibited VEGF expression and gave rise to dephosphorylated AKT, which suppressed the transmission of the mitogenic signaling pathway. Taken together, this study could provide a strategy for the rational design of high-efficacy antivascular agents.