Inhibitory effect of arsenic trioxide on oral cancer cell xenografted model in nude mice

Objective To investigate the anti-tumor effect of arsenic trioxide(As203)on human oral cancer cells xenografted nude mice model.Methods Twenty-four BALB/c nude mice were divided into 4 groups in random,Group A served as control,Group B,Group C and Group D were treated with different concentration of As203.Oral squamous cancer cells SCC-4 were inoculated into the hind leg of mice.As203 was administrated to the Groups B-D twice a week for 3 consecutive weeks.The mice were sacrificed 1 week after As203 treatment and the tumors were removed.The tumor size was measured using a metric scale caliper and then fixed in neural formalin for histopathological examinations.The expression of Ki67,cleaved caspase-3 and CD31 was detected by immunohistochemistry.Results All of As203 treatment groups from low to high dose could inhibit tumor growth.The inhibitory rate was 64.95% in Group C,32.99% in Group B and 44.33% in Group D.The expression of Ki67 and microvessel density(MVD) were noticeably decreased and the expression of cleaved caspase-3 was significantly increased in Group C(As203 5.0mg/Kg) compared with the control(P0.01).There was no significant difference in the expression of Ki67,cleaved caspase-3 and CD31 between Group B and the control group(P0.05).The mice body weight in Group D was significantly lower than that in Group A and Group C(P0.05).Conclusion As203 could inhibit oral squamous cell carcinoma cells growth in BALB/c nude mice xenografts,which may be mediated by inhibiting proliferation and angiogenesis and inducing apoptosis.The anticancer effect of As203 is related to the concentration.