8PFO image
Entry Detail
PDB ID:
8PFO
Keywords:
Title:
Crystal structure of WRN helicase domain in complex with HRO761
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2023-06-16
Release Date:
2024-04-24
Method Details:
Experimental Method:
Resolution:
1.90 Å
R-Value Free:
0.24
R-Value Work:
0.20
R-Value Observed:
0.20
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Bifunctional 3'-5' exonuclease/ATP-dependent helicase WRN
Mutations:E625A, R564A, R785A, R803A, E886A, R942A
Chain IDs:A
Chain Length:431
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation

Abstact

The Werner syndrome RecQ helicase WRN was identified as a synthetic lethal target in cancer cells with microsatellite instability (MSI) by several genetic screens1-6. Despite advances in treatment with immune checkpoint inhibitors7-10, there is an unmet need in the treatment of MSI cancers11-14. Here we report the structural, biochemical, cellular and pharmacological characterization of the clinical-stage WRN helicase inhibitor HRO761, which was identified through an innovative hit-finding and lead-optimization strategy. HRO761 is a potent, selective, allosteric WRN inhibitor that binds at the interface of the D1 and D2 helicase domains, locking WRN in an inactive conformation. Pharmacological inhibition by HRO761 recapitulated the phenotype observed by WRN genetic suppression, leading to DNA damage and inhibition of tumour cell growth selectively in MSI cells in a p53-independent manner. Moreover, HRO761 led to WRN degradation in MSI cells but not in microsatellite-stable cells. Oral treatment with HRO761 resulted in dose-dependent in vivo DNA damage induction and tumour growth inhibition in MSI cell- and patient-derived xenograft models. These findings represent preclinical pharmacological validation of WRN as a therapeutic target in MSI cancers. A clinical trial with HRO761 (NCT05838768) is ongoing to assess the safety, tolerability and preliminary anti-tumour activity in patients with MSI colorectal cancer and other MSI solid tumours.

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Primary Citation of related structures