Apurinic/apyrimidinic endonuclease/redox factor-1 (APE1/Ref-1) redox function negatively regulates NRF2

Area of Science:

• Molecular Biology
• Cancer Therapeutics
• Biochemistry

Background:

• Apurinic/apyrimidinic endonuclease/redox factor-1 (Ref-1) is a key protein regulating DNA repair and transcription factor redox states.
• Ref-1 is a validated therapeutic target in various cancers, including pancreatic ductal adenocarcinoma.
• Previous research has not comprehensively explored the impact of Ref-1 inhibition on transcription factor activity.

Purpose of the Study:

• To investigate the broad effects of Ref-1 inhibition on transcription factor activity.
• To identify novel interactions between Ref-1 and other cellular pathways.
• To explore the therapeutic potential of modulating the Ref-1/NRF2 axis in pancreatic cancer.

Main Methods:

• Genetic manipulation to repress Ref-1 expression.
• Utilized small molecule inhibitors targeting Ref-1.
• Assessed NRF2 activation and downstream target gene expression.
• Tested effects in various cell lines (cancerous and non-cancerous) and patient-derived tumor samples.

Main Results:

• Ref-1 repression potently activates nuclear factor erythroid-related factor 2 (NRF2) and its downstream targets in a dose-dependent manner.
• The redox function of Ref-1, not its DNA repair activity, is critical for NRF2 activation.
• This Ref-1-NRF2 interaction is conserved across different cell types and in patient-derived tumor samples.
• The mechanism does not involve reactive oxygen species.

Conclusions:

• Ref-1 inhibition represents a novel strategy to activate the NRF2 pathway.
• This interaction is relevant in pancreatic ductal adenocarcinoma and may overcome resistance to Ref-1-targeted therapies.
• Findings have significant translational implications for pancreatic cancer treatment.