Multiaction Platinum(IV) Prodrug Containing Thymidylate Synthase Inhibitor and Metabolic Modifier against Triple-Negative Breast Cancer

Inorg Chem. 2020 Sep 8;59(17):12632-12642. doi: 10.1021/acs.inorgchem.0c01736. Epub 2020 Aug 24.

Abstract

Multifunctional platinumIV anticancer prodrugs have the potential to enrich the anticancer properties and overcome the clinical problems of drug resistance and side effects of platinumII anticancer agents. Herein, we develop dual and triple action platinumIV complexes with targeted and biological active functionalities. One complex (PFL) that consists of cisplatin, tegafur, and lonidamine exhibits strong cytotoxicity against triple negative breast cancer (TNBC) cells. Cellular uptake and distribution studies reveal that PFL mainly accumulates in mitochondria. As a result, PFL disrupts the mitochondrial ultrastructure and induces significant alterations in the mitochondrial membrane potential, which further leads to an increase in production of reactive oxygen species (ROS) and a decrease in ATP synthesis in MDA-MB-231 TNBCs. Western blot analysis reveals the formation of ternary complex of thymidylate synthase, which shows the intracellular conversion of tegafur into 5-FU after its release from PFL. Furthermore, treatment with PFL impairs the mitochondrial function, leading to the inhibition of glycolysis and mitochondrial respiration and induction of apoptosis through the mitochondrial pathway. The RNA-sequencing experiment shows that PFL can perturb the pathways involved in DNA synthesis, DNA damage, metabolism, and transcriptional activity. These findings demonstrate that PFL intervenes in several cellular processes including DNA damage, thymidylate synthase inhibition, and perturbation of the mitochondrial bioenergetics to kill the cancer cells. The results highlight the significance of a triple-action prodrug for efficient anticancer therapy for TNBCs.

MeSH terms

  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Coordination Complexes / chemistry*
  • Coordination Complexes / metabolism*
  • DNA Damage
  • Drug Liberation
  • Enzyme Inhibitors / chemistry*
  • Fluorouracil / metabolism
  • Humans
  • Intracellular Space / drug effects
  • Intracellular Space / metabolism
  • Mitochondria / drug effects
  • Mitochondria / pathology
  • Platinum / chemistry*
  • Prodrugs / chemistry
  • Prodrugs / metabolism*
  • Reactive Oxygen Species / metabolism
  • Thymidylate Synthase / antagonists & inhibitors*
  • Transcription, Genetic / drug effects
  • Triple Negative Breast Neoplasms / pathology*

Substances

  • Coordination Complexes
  • Enzyme Inhibitors
  • Prodrugs
  • Reactive Oxygen Species
  • Platinum
  • Thymidylate Synthase
  • Fluorouracil