Cryoablation reshapes the immune microenvironment in the distal tumor and enhances the anti-tumor immunity

As one of the local treatments, cryoablation plays an increasingly important role in the comprehensive treatment of malignant tumors with its advantages of less trauma, high reproducibility, and minimally invasive. Activation of anti-tumor immunity, another characteristic of cryoablation, has attracted more and more attention with the extensive application of immunotherapy. Unfortunately, the mechanism by which cryoablation enhances anti-tumor immunity is still unclear. In this study, we used a multi-omics approach to investigate the effects of local cryoablation on the distal tumor microenvironment. In this study, we proved that large amounts of tumor antigens are released post-cryoablation, leading to a sterile inflammatory response in distant tumors. During this period, lysosome-related pathways are activated, resulting in overexpression of SNAP23 and STXBP2, activation of immune effector cells, suppression of the release of immunosuppressive factors, and finally enhancement of anti-tumor immunity. Finally, cryoablation turning “Cold tumors” into “Hot tumors”, which shows a broad prospect in the combined immunotherapy. Overall design: C57BL/6J mice xenografts were generated in 6-8-week-old C57BL/6J mice by subcutaneous implantation of 0.5 × 106 cells (one injection site per mouse/ both side). Animals were randomized in two groups (control VS cryoablation) for collection and analysis. On the 7th day, the subcutaneous tumor of the mice grew to about 5-6mm in diameter. After anesthesia, one side of the tumor was subjected to cryoablation . The cryoprobes were inserted into the targeted lesions, and two 20-sec freezing cycles, separated by a passive 20-sec and an active 20-sec thawing session, were performed.In order to further study the molecular mechanism of the enhancement of anti-tumor immunity by cryoablation, the mice were sacrificed on the D5 day after freezing and then the contralateral tumors were immediately frozen in liquid nitrogen for 15 min and stored at -80 °C, parallel Bulk RNA sequencing.