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Metnase and EEPD1: DNA Repair Functions and Potential Targets in Cancer Therapy
Jac A Nickoloff1, Neelam Sharma1, Lynn Taylor1
1Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, United States.
Abstract:
Cells respond to DNA damage by activating signaling and DNA repair systems, described as the DNA damage response (DDR). Clarifying DDR pathways and their dysregulation in cancer are important for understanding cancer etiology, how cancer cells exploit the DDR to survive endogenous and treatment-related stress, and to identify DDR targets as therapeutic targets. Cancer is often treated with genotoxic chemicals and/or ionizing radiation. These agents are cytotoxic because they induce DNA double-strand breaks (DSBs) directly, or indirectly by inducing replication stress which causes replication fork collapse to DSBs. EEPD1 and Metnase are structure-specific nucleases, and Metnase is also a protein methyl transferase that methylates histone H3 and itself. EEPD1 and Metnase promote repair of frank, two-ended DSBs, and both promote the timely and accurate restart of replication forks that have collapsed to single-ended DSBs. In addition to its roles in HR, Metnase also promotes DSB repair by classical non-homologous recombination, and chromosome decatenation mediated by TopoIIα. Although mutations in Metnase and EEPD1 are not common in cancer, both proteins are frequently overexpressed, which may help tumor cells manage oncogenic stress or confer resistance to therapeutics. Here we focus on Metnase and EEPD1 DNA repair pathways, and discuss opportunities for targeting these pathways to enhance cancer therapy.
Insights
The DNA damage response (DDR) is crucial in cancer. EEPD1 and Metnase proteins, involved in DNA repair, are overexpressed in cancer and represent potential therapeutic targets.
Area of Science:
- Molecular Biology
- Cancer Biology
- Genetics
Background:
- The DNA damage response (DDR) is a complex network of signaling and repair pathways that cells activate upon DNA damage.
- Understanding DDR is vital for cancer etiology, cancer cell survival mechanisms, and identifying therapeutic targets.
- Genotoxic cancer therapies induce DNA double-strand breaks (DSBs), crucial for their cytotoxic effects.
Purpose of the Study:
- To investigate the roles of EEPD1 and Metnase in DNA repair pathways.
- To explore the implications of EEPD1 and Metnase dysregulation in cancer.
- To identify EEPD1 and Metnase as potential therapeutic targets for enhancing cancer treatment.
Main Methods:
- Focus on the DNA repair functions of EEPD1 and Metnase.
- Analysis of their roles in repairing different types of DNA double-strand breaks (DSBs).
- Examination of their involvement in replication fork restart and other DNA repair processes.
Main Results:
- EEPD1 and Metnase are structure-specific nucleases that promote the repair of two-ended DSBs.
- Both proteins facilitate the timely and accurate restart of collapsed replication forks.
- Metnase also contributes to non-homologous end joining and chromosome decatenation.
Conclusions:
- While not commonly mutated, EEPD1 and Metnase are frequently overexpressed in cancer.
- This overexpression may aid tumor cells in managing oncogenic stress and resisting therapy.
- Targeting Metnase and EEPD1 DNA repair pathways offers promising opportunities to improve cancer therapy efficacy.
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