Glucose conjugated platinum(II) complex: Antitumor superiority to oxaliplatin, combination effect and mechanism of action

Abstract

A glucose-conjugate of (trans-R,R-cyclohexane-1,2-diamine)-2-fluoromalonato-platinum(II) complex (Glu-Pt) is designed to target tumor-specific active glucose transporters (GLUTs). Despite of very high water solubility, Glu-Pt exhibits improved cytotoxicity as compared to oxaliplatin. In this study, we investigated the in vivo toxicity profiles with the maximum tolerated dose (MTD) evaluation followed by antitumor efficacy study in leukemia-bearing DBA/2 mice. Glu-Pt showed 6-fold increase in the MTD and was more efficacious against mouse L1210 ascetic leukemia than oxaliplatin at equitoxic doses. To explore the combination effect of Glu-Pt and compare with oxaliplatin-based FOLFOX chemotherapy, we investigated the two-component synergistic antitumor activity of Glu-Pt with folinic acid (FA) and 5-fluorouracil (5-FU) respectively in five human cancer cell lines followed by a comparison study with oxaliplatin in a fixed three-component in vitro FOFLOX combination. As the result, Glu-Pt exhibited superior synergistic cytotoxicity compared to oxaliplatin. Flow cytometry-based cell cycle and apoptosis study demonstrated that Glu-Pt follows the same mechanistic principles as of oxaliplatin. Glu-Pt monotherapy and its combination with FA and 5-FU may result in improved efficacy over oxaliplatin and FOLFOX regimen. The study provides fundamental data supporting the potential of Glu-Pt as a drug candidate for further (pre)clinical development.