Abstract: Objective: To investigate the effects of different doses and infusion methods of recombinant mouse interleukin-18(rmIL-18) on the survival time and tumor diameter of the mice with hepatocellular carcinoma, and to elucidate the rational application of rmIL-18 in vivo. Methods: A total of 60 Babl/C mice were randomly divided into 5 μg rmIL-18 intraperitoneal injection group, 0.5 μg rmIL-18 intraperitoneal injection group, 0.5 μg rmIL-18 tumor injection group, cytotoxic T lymphocyte(CTL) intraperitoneal injection group, CTL tumor injection group and saline control group;there were 10 mice in each group. From the 10th day of inoculation, the mice in different rmIL-18 groups were injected with the corresponding doses and methods. The mice in different CTL groups were injected with tumor-specific CTL (1×10⁶/mouse) by intraperitoneal and intratumoral injection. The mice in saline control group were injected with an equal volume (100 μL) of saline, the injections were performed 10 times. The diameters of mice were measured weekly and the survival time was recorded. Results: Compared with 5 μg rmIL-18 intraperitoneal injection group, 0.5 μg rmIL-18 intraperitoneal injection group and saline control group, the tumor growth rate of the mice in 0.5 μg rmIL-18 tumor injection group was decreased (P<0.01)and the survival rate of the mice was increased (P<0.01); compared with 0.5 μg rmIL-18 intraperitoneal injection group, the tumor growth rate and the survival rate of the mice in CTL intraperitoneal injection group were decreased (P<0.01);compared with 0.5 μg rmIL-18 tumor injection group,the tumor growth rate and the survival rate of the mice in CTL tumor injection group were decreased (P<0.01). Conclusion: The best way for rmIL-18 anti-tumor effect is tumor injection and the effect has a dose-dependent manner.

Key words: liver neoplasms, recombinant mouse interleukin-18, cytotoxic T lymphocyte