Objective To investigate the radiosensitizing effects of 9401 on mice bearing H22 hepatoma.

Methods Mouse model bearing H22 hepatoma cells were established. Mice were randomly divided into six groups, the control group, the radiation group and four treatment groups including 9401 at high, medium and low dosages and nicotinamide combined with radiation. After irradiated, the growth of tumor was observed, the time of tumor growth was recorded, the delay time of tumor growth and enhancement factor(EF)were calculated. After 28 days, the mice were killed, the tumors were stripped and inhibition rate was calculated.

Results Groups of 9401 combined with radiation could pestpone tumor growth. The difference was statistically significant between 9401 groups at high, medium dosages combined with radiation and nicotinamide combined with radiation group (t=24.7 and 7.5, both P < 0.01). Compared with radiation alone group, groups of 9401 combined with radiation had significant radiosensitizing effect. The enhancement factor of 9401 combined with radiation groups at high and medium dosages were 2.13 and 1.73 respectively, they were significant higher than nicotinamide combined with radiation group(t=2.26 and 9.04, both P < 0.05). The inhibition rate of 9401 groups at high, medium and low dosages combined with radiation were 64.5%, 50.9% and 42.6% respectively. The inhibition rate of nicotinamide group combined radiation was 53.2%. The inhibition rate of 9401 at high dosage combined with radiation had significant difference with nicotinamide combined radiation(t=2.8, P < 0.05). Nicotinamide combined with radiation group, 9401 combined with radiation groups could significant inhibit the growth of tumors compared with radiation alone group(t=5.7, 4.0 and 2.2, all P < 0.05).

Conclusion 9401 can inhibit the tumor growth and the inhibition effect increases gradually with the drug dose increasing. It also has radiosensitizing effects on mice bearing H22 hepatoma and present broadly clinical practice prospect.