Context-dependent cell cycle checkpoint abrogation by a novel kinase inhibitor
Andrew J Massey1, Jenifer Borgognoni, Carol Bentley
1Vernalis R&D Ltd, Granta Park, Cambridge, United Kingdom. a.massey@vernalis.com
Plos One
|October 27, 2010
Summary
A new kinase inhibitor, VER-150548, blocks DNA damage checkpoints, causing cancer cell death. This molecule probes the interplay between cell cycle checkpoints and DNA damage response, offering insights into cell death mechanisms.
Area of Science:
- Cell Biology
- Molecular Biology
- Pharmacology
Background:
- Checkpoint kinase 1 and 2 (Chk1/Chk2) and Aurora kinases are crucial for DNA damage response and mitotic spindle checkpoints.
- Understanding the interplay between these checkpoints is vital for cancer therapy.
Purpose of the Study:
- To identify and characterize a novel small molecule inhibitor targeting Chk1/Chk2 and Aurora kinases.
- To investigate the functional relationship between DNA damage response and mitotic checkpoints using this inhibitor.
Main Methods:
- Fragment screening, structure-guided design, and kinase cross-screening were employed.
- X-ray crystallography was used to elucidate the structural basis for kinase specificity.
- Cellular assays were performed on human carcinoma cells, including DNA content analysis and cell death assessment.
Main Results:
- A potent inhibitor, VER-150548, targeting Chk1/Chk2 (IC50s 35/34 nM) and Aurora A/B (IC50s 101/38 nM) was identified.
- VER-150548 induced DNA reduplication and cell death in carcinoma cells, consistent with Aurora kinase inhibition.
- In the presence of DNA damage, VER-150548 abrogated cell cycle checkpoints, leading to increased DNA damage and rapid cell death in p53-defective cells.
Conclusions:
- VER-150548 abrogates DNA damage checkpoints, forcing cells into lethal mitosis.
- Premature cell death induced by Chk1 inhibition prevents cell cycle re-entry and DNA reduplication.
- This inhibitor serves as a valuable tool for studying the temporal dynamics of cell cycle checkpoints, DNA damage, and cell death pathways.
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