As2O3对人胃癌细胞株SCG-7901裸鼠移植瘤的抗肿瘤机制研究

目的：探讨不同剂量的三氧化二砷（As2O3）对人胃癌细胞株SCG-7901裸鼠皮下移植瘤的抗肿瘤机制。方法：建立人胃癌裸鼠皮下移植瘤模型，随机分为实验组即As2O3低剂量组（1．0mg／kg）、As2O3中剂量组（2．5mg／kg）和As2O3高剂量组（5．0mg／kg），空白对照生理盐水组及阳性对照5-Fu组（20mg／kg），分别腹腔连续给药10天，停药后24小时处死裸鼠，称取瘤重，计算抑瘤率，流式细胞仪检测凋亡率及Caspase-3的活性变化。结果：低剂量As2O3组及5-FU组抑瘤率分别为60．6％及78．2％，与生理盐水组比较均有统计学意义（P〈0．05），低剂量组与5-FU组抑瘤率差异无统计学意义（P〉0．05）；高、中、低剂量As2O3组流式细胞仪检测时均出现典型凋亡峰，凋亡率分别为18．32％、17．86％、21．89％，同时伴有Caspase-3活性的增加，其中低剂量As2O3活性增加最显著。结论：低剂量As2O3在体内可通过活化Caspase-3诱导细胞凋亡而发挥抗肿瘤作用。

Anti-tumor mechanism analysis of arsenic trioxide on the subcutaneously transplanted tumor of human gastric carcinoma in nude mice

Objective:To study the machanism of arsenic trioxide at different concentration on human gastric cell line SCG-7901 implanted under the skin of nude mice in vivo.Methods:The subcutaneous transplantable tumor model of human gastric carcinoma in nude mice were established and then were divided at random into five groups:1.0,2.5,5.0 mg/kg As2O3,saline and 5-FU group,each of which was composed of five nude mice and then received intraperitonal injection in the following ten days.The tumor inhibition rate was calculated to evaluate the anti-tumor effect.The apoptosis rate and the active caspase-3 were detected by the flow cytometer.Results:1.0mg/kg As2O3 and 5-FU groups could obviously inhibit the growth of transplantable tumor with the tumor inhibitory rate of 48.1% and 71.3% respectively.In contrast to the group of saline,the difference is significant(P<0.05),but the difference between 1.0mg/kg As2O3 and 5-FU group is not significant(P>0.05).The apoptotic peak was observed in the As2O3 groups with the apoptosis rate 18.32%,17.86%,21.89% for the 1.0mg/kg,2.5mg/kg and 5.0mg/kg As2O3group respectively and the increase of caspase-3 activity was observed in each As2O3 group.Conclusion:As2O3 could inhibit the growth of the human gastric subcutaneous transplantable tumor by regulating up the activity of Caspase-3 and inducing the cell apoptosis in vivo.