FBH1 deficiency sensitizes cells to WEE1 inhibition by promoting mitotic catastrophe
Lucy Jennings1, Heather Andrews Walters1, Tyler J McCraw1
1Department of Genetics and Biochemistry, Clemson University, United States.
Abstract:
WEE1 kinase phosphorylates CDK1 and CDK2 to regulate origin firing and mitotic entry. Inhibition of WEE1 has become an attractive target for cancer therapy due to the simultaneous induction of replication stress and inhibition of the G2/M checkpoint. WEE1 inhibition in cancer cells with high levels of replication stress results in induction of replication catastrophe and mitotic catastrophe. To increase potential as a single agent chemotherapeutic, a better understanding of genetic alterations that impact cellular responses to WEE1 inhibition is warranted. Here, we investigate the impact of loss of the helicase, FBH1, on the cellular response to WEE1 inhibition. FBH1-deficient cells have a reduction in ssDNA and double strand break signaling indicating FBH1 is required for induction of replication stress response in cells treated with WEE1 inhibitors. Despite the defect in the replication stress response, FBH1-deficiency sensitizes cells to WEE1 inhibition by increasing mitotic catastrophe. We propose loss of FBH1 is resulting in replication-associated damage that requires the WEE1-dependent G2 checkpoint for repair.
Insights
Loss of the helicase FBH1 sensitizes cancer cells to WEE1 inhibition by increasing mitotic catastrophe. FBH1 is required for the replication stress response following WEE1 inhibition.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- WEE1 kinase regulates cell cycle progression by phosphorylating CDK1/CDK2.
- WEE1 inhibition is a promising cancer therapy, inducing replication stress and G2/M checkpoint abrogation.
- Understanding genetic factors influencing WEE1 inhibitor response is crucial for therapeutic development.
Purpose of the Study:
- To investigate the role of the helicase FBH1 in cellular response to WEE1 inhibition.
- To determine if FBH1 deficiency impacts WEE1 inhibitor-induced replication and mitotic stress.
Main Methods:
- Utilized WEE1 inhibitors in cancer cell models.
- Assessed DNA damage signaling (ssDNA, double-strand breaks) in response to WEE1 inhibition.
- Evaluated FBH1-deficient cells for sensitivity to WEE1 inhibition and cell death induction.
Main Results:
- FBH1-deficient cells showed reduced replication stress response signaling upon WEE1 inhibition.
- Despite impaired replication stress signaling, FBH1-deficiency sensitized cells to WEE1 inhibition.
- Increased mitotic catastrophe was observed in FBH1-deficient cells treated with WEE1 inhibitors.
Conclusions:
- FBH1 is essential for the induction of the replication stress response following WEE1 inhibition.
- Loss of FBH1 enhances sensitivity to WEE1 inhibition, primarily through increased mitotic catastrophe.
- Replication-associated damage in FBH1-deficient cells may rely on the WEE1-dependent G2 checkpoint for repair.
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