Polymerase theta (Polθ) and cancer: Role in tumor progression and potential as a therapeutic target

Area of Science:

• Molecular Biology
• Genetics
• Cancer Research

Background:

• DNA double-strand breaks (DSBs) are critical DNA damage events impacting genomic stability.
• Cellular repair pathways are essential for cell growth, development, and preventing genomic instability.
• Homologous recombination (HR) deficiencies, often due to BRCA1/2 mutations, are linked to increased cancer risk.

Purpose of the Study:

• To review DNA double-strand break (DSB) repair pathways, focusing on DNA polymerase theta (Polθ).
• To explore the role of Polθ in polymerase theta-mediated end-joining (TMEJ) and its biological functions.
• To examine the therapeutic potential of Polθ inhibitors in cancer, particularly in HR-deficient cancers.

Main Methods:

• Literature review of DSB repair mechanisms.
• Analysis of Polθ structure, function, and its role in TMEJ.
• Examination of synthetic lethal interactions between Polθ and DNA repair genes.
• Review of Polθ inhibitors' therapeutic effects and clinical applications.

Main Results:

• Polθ plays a key role in the TMEJ pathway of DSB repair.
• Inhibiting Polθ demonstrates synthetic lethality in HR-deficient cancer cells (e.g., BRCA1/2 mutated).
• Polθ inhibitors show potential as targeted anticancer therapies.

Conclusions:

• Polθ is a promising therapeutic target for cancers with homologous recombination deficiencies.
• Further research is needed to overcome challenges in clinical applications of Polθ inhibitors.
• Targeting Polθ offers a potential strategy for novel anticancer therapies, especially in HR-deficient tumors.