KCl enhances the cryoablation-induced antitumor immune response: A hepatocellular carcinoma murine model research

Abstract

Cryoablation is a valuable treatment for liver cancer. To investigate the effect of KCl solution on the immunological response post cryoablation, we created a tumor-bearing mice model by subcutaneously implanting Hepal-6 cells in adult Balb/c mice. Subsequently, the mice were randomly assigned to three groups: group A (sham cryoablation), group B (cryoablation), and group C (cryoablation plus KCl solution). Mice were sacrificed on days 0, 7, and 14 post-treatment. Immune cell populations were assessed using flow cytometry. Blood samples were analyzed for serum IL-4, HSP70, and TGF-β1 levels with ELISA assays. Ablated tissues stained with immunohistochemistry were utilized to evaluate Ki67 expression at the margins of the ablation site. Our findings revealed higher HSP70 expression levels in groups B and C compared to group A. Cryoablation triggered an immune response, which was enhanced by KCl. On days 0, 7, and 14, the percentages of CD4⁺ T cells, CD8⁺ T cells, and NK cells in the spleen of group C were significantly increased compared with groups A and B. Additionally, the Th1/Th2 ratio was significantly increased in group C. Serum TGF-β1 expression was elevated after cryoablation, but KCl solution reduced the high TGF-β1 expression after cryoablation and decreased the invasiveness of cancer cells. Finally, the proliferative activity of untreated tumor tissue was significantly reduced in group C compared to groups A and B. In summary, Cryoablation triggered a systemic immune response in tumor-bearing mice, which was further boosted by combining cryoablation with a KCl solution.