中文摘要：

目的评估全反式维甲酸（ATRA）联合单纯疱疹病毒腺苷激酶（HSV-tk）基因对髓母细胞瘤细胞系Daoy的杀伤作用。方法观察不同浓度ATRA对Daoy细胞生长的抑制作用;HSV-tk基因稳定转染人的髓母细胞瘤细胞系Daoy,获得Daoy-tk细胞;Daoy-tk细胞与Daoy细胞按不同比例混合,给予不同浓度的更昔洛韦（GCV）和一定浓度的ATRA,7d后应用噻唑蓝（MTT）法测定细胞生存率。结果 ATRA在0.5～1μmol/L时即可对Daoy细胞生长产生抑制作用;Daoy-tk与Daoy细胞比例达到1：4时仍有明显的抗肿瘤作用,联合应用1μmol/L的ATRA后能显著提高HSV-tk基因对Daoy细胞的杀伤率。结论 ATRA与HSV-tk/GCV系统联合应用,能增强对人的髓母细胞瘤的杀伤作用。

英文摘要：

Objective To evaluate the synergistic lethal effect of all-trans retinoic acid and herpes simplex virus-thymidine kinase gene on medulloblastoma（MB）.Methods MB cell line Daoy cells were exposed to different concentrations of ATRA,to study the inhibitory effect of ATRA on Daoy cells;Co-cultured Daoy-tk and Daoy cells at various ratios,treated with different concentrations of GCV and a certain concentration of ATRA.The viability of the cells were measured on day 7 with MTT assay.Results ATRA could inhibit the grow of Daoy cells at the concentration 0.5 to 1μmol/L.The Daoy-tk cells had an evident anti-tumor effect when Daoy-tk：Daoy at the ratio as low as 1：4,and the antitumor effect was stronger with 1μmol/L ATRA.Conclusion Combination of ATRA and HSV-tk/GCV system have a synergistic killing effect on medulloblastoma.