Challenges for the Discovery of Non-Covalent WRN Helicase Inhibitors

Area of Science:

• Biochemistry
• Pharmacology
• Oncology

Background:

• Werner Syndrome RecQ helicase (WRN) is a synthetic lethal target for treating microsatellite instability (MSI) cancers.
• Identifying specific WRN inhibitors has been difficult due to artefacts caused by unspecific protein interference.

Purpose of the Study:

• To evaluate previously identified WRN helicase inhibitors.
• To highlight challenges in WRN inhibitor discovery.
• To propose the need for innovative screening strategies.

Main Methods:

• Extensive biochemical and biophysical assays were used.
• Characterization of previously published WRN helicase inhibitors (ML216, NSC19630, NSC617145).

Main Results:

• Previously published WRN helicase inhibitors were found to be non-specific.
• These compounds exhibited artefacts through protein interference, inhibiting WRN enzymatic activities via multiple, unspecific mechanisms.
• Existing inhibitors could be ruled out as specific WRN helicase probes.

Conclusions:

• Successful drug discovery of specific, non-covalent WRN helicase inhibitors requires innovative screening strategies.
• The development of WRN inhibitors for MSI cancer treatment remains a significant challenge due to screening artefacts.