Essential role of DNA base excision repair on survival in an acidic tumor microenvironment

Area of Science:

• Molecular Biology
• Cancer Biology
• Biochemistry

Background:

• The base excision repair (BER) pathway is crucial for repairing oxidative DNA damage.
• Many DNA repair pathways are downregulated in the tumor microenvironment, but APE1/Ref1, key in BER, is often overexpressed in solid tumors.
• APE1/Ref1 possesses dual roles in DNA repair and redox regulation.

Purpose of the Study:

• To investigate the impact of inhibiting the BER pathway in an acidic tumor microenvironment.
• To explore the potential of BER inhibition as a cancer therapy strategy.

Main Methods:

• Inhibition of the base excision repair (BER) pathway.
• Analysis of oxidative DNA damage and reactive oxygen species levels.
• Assessment of cell cycle arrest, DNA double-strand breaks, and cell death.

Main Results:

• BER inhibition in an acidic tumor microenvironment leads to increased oxidative DNA damage and reactive oxygen species.
• Unrepaired DNA damage causes cell cycle arrest, DNA double-strand breaks, and subsequent cell death.
• Upregulation of BER in solid cancers appears to be an adaptive survival mechanism.

Conclusions:

• BER inhibition can induce targeted cytotoxicity in the tumor microenvironment of human cancers.
• BER inhibition represents a rational approach for cancer therapy, potentially in combination with other treatments.
• The dual functionality of APE1/Ref1 likely serves to counteract oxidative stress in the cellular environment.