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Detours to Replication: Functions of Specialized DNA Polymerases during Oncogene-induced Replication Stress
Wei-Chung Tsao1, Kristin A Eckert2
1Department of Pathology, The Jake Gittlen Laboratories for Cancer Research, Hershey, PA 17033, USA. wxt139@psu.edu.
Abstract:
Incomplete and low-fidelity genome duplication contribute to genomic instability and cancer development. Difficult-to-Replicate Sequences, or DiToRS, are natural impediments in the genome that require specialized DNA polymerases and repair pathways to complete and maintain faithful DNA synthesis. DiToRS include non B-DNA secondary structures formed by repetitive sequences, for example within chromosomal fragile sites and telomeres, which inhibit DNA replication under endogenous stress conditions. Oncogene activation alters DNA replication dynamics and creates oncogenic replication stress, resulting in persistent activation of the DNA damage and replication stress responses, cell cycle arrest, and cell death. The response to oncogenic replication stress is highly complex and must be tightly regulated to prevent mutations and tumorigenesis. In this review, we summarize types of known DiToRS and the experimental evidence supporting replication inhibition, with a focus on the specialized DNA polymerases utilized to cope with these obstacles. In addition, we discuss different causes of oncogenic replication stress and its impact on DiToRS stability. We highlight recent findings regarding the regulation of DNA polymerases during oncogenic replication stress and the implications for cancer development.
Insights
Difficult-to-Replicate Sequences (DiToRS) impede DNA synthesis, contributing to cancer. Specialized DNA polymerases are crucial for overcoming these genomic obstacles and maintaining stability, especially under oncogenic stress.
Area of Science:
- Genetics
- Molecular Biology
- Cancer Biology
Background:
- Incomplete genome duplication causes genomic instability and cancer.
- Difficult-to-Replicate Sequences (DiToRS) are genomic impediments requiring specialized DNA polymerases for faithful synthesis.
- DiToRS include non-B DNA structures in repetitive sequences like fragile sites and telomeres, inhibiting replication.
Purpose of the Study:
- To review known DiToRS and evidence of replication inhibition.
- To focus on specialized DNA polymerases that manage replication obstacles.
- To discuss oncogenic replication stress, its impact on DiToRS, and implications for cancer.
Main Methods:
- Literature review of DiToRS and DNA polymerases.
- Analysis of experimental evidence for replication inhibition by DiToRS.
- Discussion of oncogenic replication stress mechanisms and their effects.
Main Results:
- Identified various DiToRS and their role in replication stress.
- Highlighted specialized DNA polymerases essential for overcoming DiToRS.
- Detailed the impact of oncogenic replication stress on DiToRS stability.
Conclusions:
- DiToRS pose significant challenges to DNA replication fidelity.
- Specialized polymerases and regulated responses are vital for preventing mutations and tumorigenesis.
- Understanding these mechanisms offers insights into cancer development and potential therapeutic strategies.
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