NF-κB signaling mediates acquired resistance after PARP inhibition

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• Poly (ADP-ribose) polymerase (PARP) inhibitors show efficacy in BRCA-mutant cancers.
• Acquired resistance limits the long-term effectiveness of PARP inhibitors.
• Mechanisms of acquired resistance to PARP inhibitors are not fully understood.

Purpose of the Study:

• To investigate the molecular mechanisms underlying acquired resistance to PARP inhibitors.
• To identify potential therapeutic strategies to overcome PARP inhibitor resistance.

Main Methods:

• Established PARP inhibitor-resistant cell lines through continuous drug treatment.
• Utilized RNA sequencing to compare gene expression profiles between resistant and parental cells.
• Performed pathway analysis to identify dysregulated signaling pathways.
• Investigated the therapeutic efficacy of NF-κB inhibitors and bortezomib in resistant cells.

Main Results:

• NF-κB signaling pathway was found to be significantly up-regulated in PARP inhibitor-resistant cells.
• Knockdown of key NF-κB signaling components restored sensitivity to PARP inhibitors in resistant cells.
• PARP inhibitor-resistant cells demonstrated sensitivity to an NF-κB inhibitor.
• Bortezomib, a proteasome inhibitor, induced cell death in PARP inhibitor-resistant cells but not in parental cells.

Conclusions:

• Up-regulation of NF-κB signaling is a critical mechanism driving acquired resistance to PARP inhibitors.
• Targeting NF-κB signaling with inhibitors or using bortezomib represents a promising therapeutic approach for patients who develop resistance to PARP inhibitors.