Related Experiment Video
Updated: Jun 15, 2025
Visualizing DNA Damage Repair Proteins in Patient-Derived Ovarian Cancer Organoids via Immunofluorescence Assays
Published on: February 24, 2023
GPX4 Inhibition Enhances the Antitumor Effect of PARP Inhibitor on Homologous Recombination Proficient Ovarian Cancer
Jiaxin Gu1,2, Senmi Qian1,2, Fangfang Qian1,3
1Department of Gynecologic Oncology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Background:
Poly (ADP-ribose) polymerase inhibitors (PARPi) are now widely used in BRCA1/2 mutation or homologous recombination (HR) deficiency ovarian cancer but have limited efficacy in HR-proficient patients. GPX4 is a key regulator of ferroptosis and has been proven to be associated with multiple drug sensitivities. As a molecule that regulates the sensitivity of multiple drugs, the relationship between GPX4 and the efficacy of PARPi in HR-proficient ovarian cancer has not been elucidated.
Methods:
In this study, siRNA transfection was used to regulate the expression of GPX4. The effect of GPX4 inhibition on HR-proficient ovarian cancer was determined by CCK-8 assay and flow cytometry. Immunofluorescence and comet assay were used to reflect DNA damage. ROS production was measured using DCFH-DA and flow cytometry. The combination index of PARP inhibitors and RSL3 was calculated using CompuSyn software based on Chou- Talalay methodology.
Results:
GPX4 inhibition confers HR-proficient ovarian cancer cells sensitive to PARPi due to ROS generation and oxidative stress caused DNA double-strand breakage. The combination of olaparib and niraparib with GPX4 inhibitor RSL3 also showed a synergistic effect.
Conclusion:
Combining GPX4 inhibition with PARP inhibitors resulted in a notable increase in DNA damage, ultimately causing the death of cancer cells with proficient HR pathways. Our findings may provide new therapeutic options for HR-proficient patients to benefit from PARP inhibitors and improve outcomes.
Insights
Inhibiting GPX4 makes ovarian cancer cells with proficient HR pathways sensitive to Poly (ADP-ribose) polymerase inhibitors (PARPi). This combination increases DNA damage and cell death, offering new therapeutic options.
Area of Science:
- Oncology
- Molecular Biology
- Drug Development
Background:
- Poly (ADP-ribose) polymerase inhibitors (PARPi) are effective in HR-deficient ovarian cancer but not HR-proficient.
- GPX4 regulates ferroptosis and drug sensitivity, but its role with PARPi in HR-proficient ovarian cancer is unknown.
Purpose of the Study:
- To investigate the role of GPX4 in the efficacy of PARPi in HR-proficient ovarian cancer.
- To determine if targeting GPX4 can sensitize HR-proficient ovarian cancer to PARPi.
Main Methods:
- GPX4 expression was modulated using siRNA.
- Cell viability was assessed via CCK-8 assay and flow cytometry.
- DNA damage, ROS production, and drug synergy (PARPi + RSL3) were evaluated.
Main Results:
- GPX4 inhibition sensitized HR-proficient ovarian cancer cells to PARPi.
- This sensitization was linked to increased ROS generation and oxidative stress-induced DNA double-strand breaks.
- Combination therapy with olaparib/niraparib and RSL3 demonstrated synergistic effects.
Conclusions:
- GPX4 inhibition enhances PARPi efficacy in HR-proficient ovarian cancer by inducing DNA damage and cell death.
- This strategy presents a potential therapeutic approach for HR-proficient ovarian cancer patients.
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
02:31Homologous Recombination