Related Experiment Video
Updated: Jun 24, 2025
Anticancer Metal Complexes: Synthesis and Cytotoxicity Evaluation by the MTT Assay
Published on: November 10, 2013
Masking the Bioactivity of Hydroxamic Acids by Coordination to Cobalt: Towards Bioreductive Anticancer Agents
David M Goodman1, Cornelia U Ritter1, Erin Chen1
1School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
Abstract:
The clinical use of many potent anticancer agents is limited by their non-selective toxicity to healthy tissue. One of these examples is vorinostat (SAHA), a pan histone deacetylase inhibitor, which shows high cytotoxicity with limited discrimination for cancerous over healthy cells. In an attempt to improve tumor selectivity, we exploited the properties of cobalt(III) as a redox-active metal center through stabilization with cyclen and cyclam tetraazamacrocycles, masking the anticancer activity of SAHA and other hydroxamic acid derivatives to allow for the complex to reach the hypoxic microenvironment of the tumor. Biological assays demonstrated the desired low in vitro anticancer activity of the complexes, suggesting effective masking of the activity of SAHA. Once in the tumor, the bioactive moiety may be released through the reduction of the CoIII center. Investigations revealed long-term stability of the complexes, with cyclic voltammetry and chemical reduction experiments supporting the design hypothesis of SAHA release through the reduction of the CoIII prodrug. The results highlight the potential for further developing this complex class as novel anticancer agents by masking the high cytotoxicity of a given drug, however, the cellular uptake needs to be improved.
Insights
Researchers developed novel cobalt(III) complexes to mask the potent anticancer drug vorinostat (SAHA). These complexes are designed for targeted release in hypoxic tumors, reducing toxicity to healthy tissues.
Area of Science:
- Medicinal Chemistry
- Drug Delivery Systems
- Cancer Therapeutics
Background:
- Potent anticancer agents like vorinostat (SAHA) exhibit non-selective toxicity, limiting their clinical application.
- Histone deacetylase inhibitors (SAHA) show high cytotoxicity but lack discrimination between cancerous and healthy cells.
Purpose of the Study:
- To develop novel cobalt(III)-based prodrugs to mask the activity of SAHA for improved tumor selectivity.
- To enable targeted delivery of SAHA to the hypoxic tumor microenvironment.
Main Methods:
- Synthesis and characterization of cobalt(III) complexes stabilized by cyclen and cyclam tetraazamacrocycles.
- In vitro biological assays to evaluate anticancer activity and masking of SAHA.
- Cyclic voltammetry and chemical reduction experiments to confirm prodrug activation mechanism.
Main Results:
- The cobalt(III) complexes demonstrated low in vitro anticancer activity, indicating effective masking of SAHA.
- Long-term stability of the complexes was observed.
- Experiments supported the hypothesis of SAHA release via reduction of the Co(III) center in the tumor.
Conclusions:
- Cobalt(III) complexes show potential as novel anticancer agents by masking drug cytotoxicity for targeted delivery.
- Further development is needed to improve cellular uptake of these prodrugs.
More Related Videos
08:40Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
09:00An In Vitro Enzymatic Assay to Measure Transcription Inhibition by GalliumIII and H3 5,10,15-trispentafluorophenylcorroles
Published on: March 18, 2015
Related Concept Videos
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:46Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
02:54Coordination Compounds and Nomenclature
02:49Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...