JQ1-Loaded Polydopamine Nanoplatform Inhibits c-MYC/Programmed Cell Death Ligand 1 to Enhance Photothermal Therapy...

Area of Science:

• Oncology
• Nanotechnology
• Immunotherapy

Background:

• Programmed cell death ligand 1 (PD-L1) blockade is effective in cancer immunotherapy, but limited in triple-negative breast cancer (TNBC).
• Triple-negative breast cancer (TNBC) requires novel therapeutic strategies beyond current PD-L1 antibody treatments.

Purpose of the Study:

• To develop a novel nanoplatform for synergistic triple therapy against TNBC.
• To investigate the efficacy of JQ1, photothermal therapy (PTT), and immunotherapy in combination for TNBC treatment.

Main Methods:

• Utilized bromodomain and extra-terminal inhibitor JQ1 to down-regulate PD-L1 expression in TNBC.
• Developed polydopamine nanoparticles (PDMNs) loaded with JQ1 (PDMN-JQ1) for targeted delivery and PTT.
• Evaluated the synergistic effects of JQ1, PTT, and immunotherapy on TNBC in a mouse model.

Main Results:

• JQ1 effectively down-regulated PD-L1 expression and inhibited TNBC growth by targeting the BRD4-c-MYC axis.
• The PDMN-JQ1 nanoplatform demonstrated continuous JQ1 release and induced effective PTT.
• The synergistic triple therapy significantly activated cytotoxic T lymphocytes and established a robust immune-memory effect, protecting against tumor re-challenge.

Conclusions:

• The developed nanoplatform offers a compact and simple approach for triple therapy (targeted therapy, PTT, immunotherapy) in TNBC.
• This strategy shows potential for overcoming the limitations of current PD-L1 blockade treatments in TNBC.
• The study highlights the promise of combining targeted agents with nanomedicine for enhanced cancer immunotherapy and long-term protection.