Abstract
To identify genes whose loss confers resistance to CHK1 inhibitors, we perform genome-wide CRISPR-Cas9 screens in non-small-cell lung cancer (NSCLC) cell lines treated with the CHK1 inhibitor prexasertib (CHK1i). Five of the top six hits of the screens, MYBL2 (B-MYB), LIN54, FOXM1, cyclin A2 (CCNA2), and CDC25B, are cell-cycle-regulated genes that contribute to entry into mitosis. Knockout of MMB-FOXM1 complex components LIN54 and FOXM1 reduce CHK1i-induced DNA replication stress markers and premature mitosis during Late S phase. Activation of a feedback loop between the MMB-FOXM1 complex and CDK1 is required for CHK1i-induced premature mitosis in Late S phase and subsequent replication catastrophe, indicating that dysregulation of the S to M transition is necessary for CHK1 inhibitor sensitivity. These findings provide mechanistic insights into small molecule inhibitors currently studied in clinical trials and provide rationale for combination therapies.
Keywords:
CDK1; CHK1; FOXM1; LIN54; MYBL2; MuvB; cell cycle checkpoint; non-small-cell lung cancer; prexasertib.
Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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A549 Cells
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Antineoplastic Agents / pharmacology*
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Carcinoma, Non-Small-Cell Lung / drug therapy*
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Carcinoma, Non-Small-Cell Lung / enzymology
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Carcinoma, Non-Small-Cell Lung / genetics
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Carcinoma, Non-Small-Cell Lung / pathology
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Cell Cycle Checkpoints / drug effects
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism*
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Checkpoint Kinase 1 / antagonists & inhibitors*
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Checkpoint Kinase 1 / genetics
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Checkpoint Kinase 1 / metabolism
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Forkhead Box Protein M1 / genetics
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Forkhead Box Protein M1 / metabolism*
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Gene Expression Regulation, Neoplastic
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Humans
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Lung Neoplasms / drug therapy*
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Lung Neoplasms / enzymology
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Lung Neoplasms / genetics
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Lung Neoplasms / pathology
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Mitosis / drug effects*
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Multiprotein Complexes
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Protein Kinase Inhibitors / pharmacology*
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Pyrazines / pharmacology*
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Pyrazoles / pharmacology*
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Signal Transduction
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Trans-Activators / genetics
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Trans-Activators / metabolism*
Substances
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Antineoplastic Agents
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Cell Cycle Proteins
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FOXM1 protein, human
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Forkhead Box Protein M1
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Lin54 protein, human
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MYBL2 protein, human
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Multiprotein Complexes
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Protein Kinase Inhibitors
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Pyrazines
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Pyrazoles
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Trans-Activators
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prexasertib
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CHEK1 protein, human
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Checkpoint Kinase 1