RelA Is an Essential Target for Enhancing Cellular Responses to the DNA Repair/Ref-1 Redox Signaling Protein and...

Area of Science:

• Oncology
• Molecular Biology
• Cancer Signaling

Background:

• Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with limited treatment options.
• Ref-1 protein's redox signaling activates transcription factors like RelA and STAT3, crucial in PDAC progression and therapy resistance.
• The precise role of Ref-1 redox signaling via RelA in PDAC pathogenesis remains unclear.

Purpose of the Study:

• To investigate the mechanistic role of RelA in PDAC response to Ref-1 inhibition.
• To determine if STAT3 is involved in PDAC sensitivity to Ref-1 redox inhibitors.
• To explore the contribution of PRDX1 to Ref-1 inhibitor efficacy in PDAC.

Main Methods:

• Utilized genetically engineered mouse PDAC cells (KC3590) with and without functional RelA.
• Assessed sensitivity to Ref-1 redox inhibitors (APX3330, APX2009, APX2014) in RelA-deficient and proficient cells.
• Performed STAT3 knockdown, gene expression analysis (IL-8, FOSB, c-Jun), and PRDX1 knockdown experiments.

Main Results:

• RelA-deficient PDAC cells exhibited resistance to Ref-1 inhibitors; sensitivity was restored in RelA-proficient cells.
• STAT3 knockdown did not affect cellular sensitivity to Ref-1 inhibitors.
• Ref-1 inhibitors decreased IL-8, FOSB, and c-Jun expression in RelA-proficient cells.
• PRDX1 knockdown significantly enhanced PDAC cell killing by Ref-1 inhibitors, independent of ROS or NADP/NADPH ratio changes.

Conclusions:

• RelA, not STAT3, is a key mediator of PDAC cell killing by Ref-1 inhibitors.
• Disrupting the PRDX1-Ref-1 interaction offers a potential therapeutic strategy to overcome PDAC drug resistance.
• Targeting Ref-1 redox signaling, particularly through RelA, presents a promising avenue for PDAC treatment.