Cryosurgery for Treatment of Subcutaneously Xenotransplanted Tumors in Rats and its Effect on Cellular Immunity

Cryosurgery has shown encouraging therapeutic effects on some solid tumors but its effect on the cellular immunity remains unclear. We developed a subcutaneously xenotransplanted tumor model in SD rats to directly evaluate the immune response by detecting the serum cytokine levels, T-cell responses to tumor derived antigens, and the cytolytic activity of peripheral blood mononuclear cells against the W256 cancer line with apoptosis of cells being detected using TUNEL method. 66 SD rats were divided into 2 groups with group A having 36 rats and group B having 30 rats. 30 rats in group B were equally divided into 3 groups, tumor group B, cryosurgery group B and surgery group B, with 10 rats each. 36 rats in group A were equally divided into 2 groups, cryosurgery group A and tumor group A and treatment was done accordingly. The results showed that cryosurgery induced not only destruction of the tumor cells but also cell apoptosis around the cryosurgery foci. The apoptosis ratio reached the peak 12 h after cr...