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Updated: Aug 26, 2026
High-Throughput In Vitro Assay using Patient-Derived Tumor Organoids
Published on: June 14, 2021
Cytotoxic activity of tropolones against human oral tumor cell lines
Hidetsugu Wakabayashi1, Keiko Yokoyama, Kana Hashiba
1Faculty of Science, Josai University, Sakado, Saitama, 350-0295, Japan. hwaka@josai.ac.jp
Abstract:
Twenty-seven tropolone derivatives were investigated for their tumor-specific cytotoxicity, using 3 normal human cells and 3 human oral tumor cell lines. Tropolone derivatives with phenolic OH group, hinokithiol, its tosylate and methyl ethers have relatively higher tumor specificity. 5-Aminotropolone showed the highest specificity, whereas 2-aminotropone and its derivatives showed little or no specificity. 5-Aminotropolone induced apoptotic cell death characterized by internucleosomal DNA fragmentation and caspase 3 activation in the human promyelocytic leukemic HL-60 cell line. ESR spectroscopy showed that 5-aminotropolone produced radical under alkaline condition, and efficiently scavenged O2- and NO produced by HX-XOD reaction and NOC-7, respectively. These data suggest that 5-aminotropolone may induce cytotoxicity by radical-mediated redox reaction.
Insights
5-Aminotropolone exhibits high tumor specificity and induces cancer cell death via apoptosis. This tropolone derivative may exert its cytotoxic effects through radical-mediated redox reactions, offering potential for cancer therapy.
Area of Science:
- Medicinal Chemistry
- Pharmacology
- Biochemistry
Background:
- Tropolone derivatives are explored for their therapeutic potential.
- Understanding tumor-specific cytotoxicity is crucial for developing targeted cancer treatments.
Purpose of the Study:
- To investigate the tumor-specific cytotoxicity of 27 tropolone derivatives.
- To identify tropolone structures with enhanced anti-cancer activity and understand their mechanisms of action.
Main Methods:
- Cytotoxicity assays were performed on normal human cells and oral tumor cell lines.
- Apoptotic cell death was analyzed using DNA fragmentation and caspase 3 activation assays.
- Electron Spin Resonance (ESR) spectroscopy was used to study radical production and scavenging activity.
Main Results:
- Tropolone derivatives with phenolic groups, hinokitiol, tosylate, and methyl ethers showed higher tumor specificity.
- 5-Aminotropolone demonstrated the highest tumor specificity, inducing apoptosis in HL-60 leukemia cells.
- 5-Aminotropolone generated radicals under alkaline conditions and scavenged superoxide (O2-) and nitric oxide (NO) radicals.
Conclusions:
- 5-Aminotropolone is a promising candidate for tumor-specific cancer therapy.
- The cytotoxicity of 5-aminotropolone is likely mediated by radical-induced redox reactions.
- Further research into 5-aminotropolone's mechanism could lead to novel anti-cancer drug development.
