DNA polymerase theta in cancer therapy: mechanism of action and modulator development

Area of Science:

• Molecular Biology
• Cancer Therapeutics
• Drug Discovery

Background:

• DNA polymerase theta (Polθ) is crucial for the theta-mediated end-joining (TMEJ) DNA repair pathway.
• Polθ overexpression in homologous-recombination (HR)-deficient cancers, like BRCA-mutated tumors, offers a synthetic lethal target.
• Polθ's structure includes a helicase domain for DNA end capture and a polymerase domain for microhomology binding and synthesis.

Purpose of the Study:

• To review the mechanisms of Polθ inhibitors in cancer treatment.
• To provide structural insights into Polθ's ATP-binding pocket.
• To discuss current clinical trials, combination therapies, and recent advancements in Polθ modulator development.

Main Methods:

• Literature review and analysis of Polθ inhibitors.
• Examination of structural data for Polθ's ATP-binding pocket.
• Discussion of rational drug design, pharmacodynamics, and pharmacokinetics of Polθ modulators.

Main Results:

• Polθ inhibitors exploit the dependency of HR-deficient cancer cells on TMEJ for survival.
• Structural insights into the ATP-binding pocket guide the design of selective inhibitors.
• Several Polθ inhibitors are in clinical trials, with combination therapies showing promise.

Conclusions:

• Targeted inhibition of Polθ presents a viable therapeutic strategy for HR-deficient cancers.
• Continued research into Polθ modulators, including dual inhibitors, is essential for advancing cancer treatment.
• Addressing challenges in drug discovery will pave the way for future Polθ-targeted therapies.