Blocking the DNA repair system by traditional Chinese medicine?

Area of Science:

• Molecular Biology
• Pharmacology
• Computational Chemistry

Background:

• Non-homologous end joining (NHEJ) is a critical DNA repair pathway that maintains genomic stability.
• However, NHEJ can repair DNA double-strand breaks (DSBs) in cancer cells, potentially reducing the effectiveness of radiotherapy.
• Identifying novel inhibitors of NHEJ is crucial for improving cancer treatment outcomes.

Purpose of the Study:

• To identify novel inhibitors of the NHEJ pathway from traditional Chinese medicine (TCM) using computer-aided drug design (CADD).
• Specifically, to target Ku86, the initiator protein of the NHEJ pathway.
• To evaluate the potential of TCM compounds to enhance radiotherapy efficacy by disrupting cancer cell DNA repair.

Main Methods:

• Employed computer-aided drug design (CADD) to screen TCM compounds for potential Ku86 inhibition.
• Integrated binding energy evaluation and molecular dynamics simulations to assess compound-protein interactions.
• Analyzed key binding features, including salt bridges, hydrogen bonds, and pi-cation interactions.

Main Results:

• Identified four TCM compounds—glycyrrhizic acid, macedonoside C, lithospermic acid, and salvianolic acid B—as potential Ku86 inhibitors.
• All identified compounds exhibited low binding energy and stable binding poses with Ku86.
• Key binding interactions involved carboxyl groups forming salt bridges, and carbonyl or dihydroxyphenyl groups forming hydrogen bonds or pi-cation interactions, respectively.

Conclusions:

• The four TCM compounds are promising candidates for inhibiting Ku86 and disrupting the NHEJ pathway.
• These compounds have the potential to enhance the efficacy of radiotherapy in cancer treatment by preventing DNA repair in cancer cells.
• Further research into these TCM-derived Ku86 inhibitors could lead to novel therapeutic strategies for oncology.