Screening compound libraries for H₂O₂-mediated cancer therapeutics using a peroxiredoxin-based sensor

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Therapeutics

Background:

• Hydrogen peroxide (H₂O₂) is a key redox signal with therapeutic potential in cancer.
• Existing methods for identifying H₂O₂-modulating compounds lack specificity.
• Cancers sensitive to H₂O₂ offer a target for novel therapeutics.

Purpose of the Study:

• To identify small-molecule compounds that specifically modulate H₂O₂ pathways.
• To characterize cellular responses to identified H₂O₂-modulating compounds.
• To investigate the role of H₂O₂ in drug-induced oxidative stress.

Main Methods:

• Utilized a genetically encoded fluorescent probe for human peroxiredoxin-2 (Prx2) oxidation.
• Conducted high-throughput screening of small-molecule libraries.
• Performed cellular assays to assess compound-induced H₂O₂-mediated toxicity.
• Differentiated H₂O₂-specific effects from general reactive oxygen species (ROS) induction.

Main Results:

• Identified several small-molecule compounds that modulate H₂O₂ pathways.
• Demonstrated that some compounds induce H₂O₂-mediated cellular toxicity.
• Revealed that the antifungal SMER3 acts as an oxidant-inducing drug.
• Found that established ROS-inducing drugs like cisplatin do not oxidize Prx2, indicating they do not primarily induce H₂O₂.

Conclusions:

• A novel fluorescent probe enables specific screening for H₂O₂ pathway modulators.
• SMER3 is a potential H₂O₂-targeting therapeutic agent.
• Drug-induced ROS are not always mediated by H₂O₂, highlighting the need for specific probes.