HSP70-Promoter-Driven CRISPR/Cas9 System Activated by Reactive Oxygen Species for Multifaceted Anticancer Immune...

Area of Science:

• Oncology
• Immunotherapy
• Gene Editing

Background:

• Immune checkpoint blockade (ICB) therapy shows limited efficacy due to low response rates.
• Tumor cells often evade immune detection by upregulating PD-L1.
• Novel strategies are needed to enhance anti-tumor immune responses.

Purpose of the Study:

• To develop a promoter-driven CRISPR/Cas9 system (F-PC/pHCP) for permanent PD-L1 gene disruption.
• To investigate the potential of F-PC/pHCP to enhance cancer immunotherapy.
• To evaluate the system's ability to induce immunogenic cell death and reprogram the tumor microenvironment.

Main Methods:

• A chlorin e6-encapsulated fluorinated dendrimer combined with HSP70-promoter-driven CRISPR/Cas9 (F-PC/pHCP).
• Activation of the HSP70 promoter using 660 nm laser for targeted Cas9 expression.
• Assessment of PD-L1 disruption, immunogenic cell death (ICD), tumor microenvironment modulation, and anti-cancer efficacy in vivo.

Main Results:

• F-PC/pHCP achieved permanent genomic disruption of PD-L1, preventing immune escape.
• The system induced ICD in tumor cells and reprogrammed the immunosuppressive tumor microenvironment.
• Significant inhibition of primary tumor growth, distant tumor growth, and lung metastasis was observed.
• An immune memory response was stimulated, indicating long-term anti-cancer effects.

Conclusions:

• The F-PC/pHCP system offers a potent strategy for cancer immunotherapy by permanently disabling PD-L1.
• This approach enhances anti-tumor immunity through ICD induction and microenvironment reprogramming.
• F-PC/pHCP represents a promising alternative to current ICB therapy, improving treatment outcomes and preventing metastasis.