NPLOC4 Inhibition Remodels Tumor Microenvironment via M2-to-M1 Macrophage Reprogramming and Boosts Anti-PD-1 Response...

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• The PD-1/PD-L1 pathway is a key target in cancer immunotherapy, but its efficacy is limited in hepatocellular carcinoma (HCC).
• Tumor-associated macrophages (TAMs) contribute to an immunosuppressive tumor microenvironment, hindering anti-cancer immune responses.
• NPLOC4 is a potential antitumor target, but its role in TAMs and immunotherapy remains undefined.

Purpose of the Study:

• To investigate the role of NPLOC4 in TAMs and its impact on anti-PD-1/PD-L1 therapy resistance in HCC.
• To elucidate the mechanism by which NPLOC4 influences the tumor immune microenvironment.
• To evaluate the therapeutic potential of targeting NPLOC4 in combination with PD-1 blockade for HCC treatment.

Main Methods:

• Analysis of clinical HCC specimens to correlate NPLOC4+ TAMs with patient prognosis.
• Proteomic analysis, in vitro, and in vivo experiments to study NPLOC4 function in TAMs.
• Assessment of disulfiram/copper (DSF/Cu) in combination with anti-PD-1 therapy in animal models of HCC.

Main Results:

• NPLOC4+ TAMs were found to be negatively correlated with HCC patient prognosis.
• NPLOC4 was shown to inhibit the type I interferon pathway in TAMs by mediating RIG-I degradation, promoting M2 polarization, and suppressing CD8+ T-cell infiltration.
• The combination of DSF/Cu and anti-PD-1 therapy significantly inhibited HCC tumor growth in vivo.

Conclusions:

• NPLOC4+ TAMs create an immunosuppressive microenvironment in HCC by suppressing antitumor immunity.
• Targeting NPLOC4 in TAMs represents a promising strategy to overcome resistance to anti-PD-1/PD-L1 therapy in HCC.
• Combined therapy with DSF/Cu and PD-1 blockade offers a potential new treatment approach for HCC.