High-throughput evaluation of novel WRN inhibitors

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Genomic stability is maintained by DNA repair mechanisms.
• Werner syndrome helicase (WRN) is crucial for DNA double-strand break (DSB) repair and a therapeutic target in microsatellite instability-high (MSI-H) cancers.
• MSI-H tumors exhibit DNA mismatch repair defects and rely on WRN for survival.

Purpose of the Study:

• To identify and develop novel WRN inhibitors for MSI-H cancer treatment.
• To evaluate the efficacy and selectivity of WRN inhibition in MSI-H versus microsatellite stable (MSS) tumor cells.
• To leverage a knowledge-based drug discovery approach combining computational modeling and experimental assays.

Main Methods:

• Utilized in vitro biochemical assays (ATPase, helicase) and cell-based assays (viability, target engagement).
• Employed CRISPR-mediated WRN knockout to confirm lethality in MSI-H cells.
• Applied high-content imaging for DNA DSB biomarker (pH2AX) detection and cellular thermal shift assay for target engagement.
• Integrated computational modeling with screening efforts (phenotypic, ALIS, ADP glo HTS, DEL).

Main Results:

• CRISPR knockout of WRN was lethal in MSI-H cells but not MSS cells, dependent on helicase activity.
• A novel series of spirocyclic WRN inhibitors targeting MSI-H tumor cells was discovered.
• The developed inhibitors demonstrated potency and selectivity, engaging the WRN helicase.

Conclusions:

• WRN is a validated therapeutic target for MSI-H cancers.
• Targeted inhibition of WRN offers a promising strategy for selective cancer therapy.
• Interdisciplinary approaches are crucial for advancing novel therapeutic agents.