Targeting Base Excision Repair in Cancer: NQO1-Bioactivatable Drugs Improve Tumor Selectivity and Reduce Treatment...

Area of Science:

• Oncology
• Radiation Oncology
• Molecular Biology

Background:

• Ionizing radiation (IR) effectively kills tumor cells but damages healthy tissues.
• NAD(P)H:quinone oxidoreductase 1 (NQO1) is overexpressed in solid tumors, offering a potential therapeutic target.
• NQO1-bioactivatable drugs can induce tumor cell death but have dose-limiting toxicities.

Purpose of the Study:

• To review the radiosensitization mechanisms between NQO1-bioactivatable drugs and IR.
• To explore the role of base excision repair (BER) in this combined therapy.
• To highlight a tumor-selective and minimally toxic approach for NQO1-overexpressing solid tumors.

Main Methods:

• Review of existing literature on NQO1-bioactivatable agents, IR, and their synergistic effects.
• Analysis of the molecular mechanisms, including redox cycling and DNA damage response pathways.
• Focus on the involvement of poly(ADP-ribose) polymerase 1 (PARP1) and base excision repair (BER).

Main Results:

• NQO1 bioactivation leads to futile redox cycles, DNA damage, and cell death.
• Combining NQO1 drugs with IR, PARP1 inhibitors, or pyrimidine radiosensitizers enhances tumor selectivity.
• This synergy allows for reduced doses of individual agents, mitigating side effects like methemoglobinemia and hemolytic anemia.

Conclusions:

• The combination of NQO1-bioactivatable drugs and IR presents a promising strategy for cancer therapy.
• This approach leverages NQO1 overexpression for tumor-specific targeting and reduced toxicity.
• Understanding the role of BER is crucial for optimizing this minimally toxic, tumor-selective treatment.