Abscopal Effect of Frozen Autograft Reconstruction Combined with an Immune Checkpoint Inhibitor Analyzed Using a...

Area of Science:

• Oncology
• Immunology
• Orthopedics

Background:

• The abscopal effect, a phenomenon where localized cancer treatment induces systemic anti-tumor immunity, is of significant interest.
• Investigating novel therapeutic strategies to enhance the abscopal effect is crucial for improving cancer treatment outcomes.

Purpose of the Study:

• To evaluate the abscopal effect of re-implanting liquid nitrogen-treated tumor-bearing bone grafts.
• To assess the synergistic effect of anti-programmed death-1 (PD-1) therapy in combination with cryotreatment for bone metastases.

Main Methods:

• A bone metastasis model was established in C3H mice by injecting MMT-060562 cells into the tibiae.
• Tumors were treated with excision, liquid nitrogen cryotreatment, or a combination with anti-PD-1 antibody therapy.
• The abscopal effect was quantified by measuring the growth inhibition of non-treated, contralateral tumors and assessing immune cell infiltration.

Main Results:

• Re-implantation of frozen autografts significantly inhibited abscopal tumor growth.
• Anti-PD-1 antibody treatment demonstrated a more potent abscopal effect compared to cryotreatment alone.
• Anti-PD-1 therapy significantly increased CD8+ T cell infiltration and interferon-γ production in spleen cells.

Conclusions:

• Re-implantation of tumor-bearing frozen autografts can induce an abscopal effect.
• Anti-PD-1 therapy is a promising strategy to enhance the abscopal effect and anti-tumor immunity in bone metastases.
• Liquid nitrogen-treated bone grafts alone did not elicit a strong T-cell response or significant tumor suppression.