反义寡核苷酸对脑胶质瘤细胞生长抑制作用的动态研究

目的　探讨原癌基因 c- m yb反义寡核苷酸 (AON)对 C6脑胶质瘤细胞的体内生长抑制作用。方法　将 C6脑胶质瘤细胞接种于裸鼠皮下 ,当肿瘤长至 10 mm左右时随机分成 3组 (每组 12只 ) ,分别用 c- mybAON、正义寡核苷酸 (SON)和生理盐水瘤区原位注射 ,注药后 4、8、12和 16日各组处死动物 3只 ,动态观察肿瘤的体积、重量及病理学改变 ;用流式细胞仪检测肿瘤细胞的凋亡 ;以免疫组化方法分析各组的 c- m yb、bcl- 2蛋白阳性表达率。结果　 c- myb AON组的肿瘤体积抑制率分别为第 4天 6 6 .7% ,第 8天 71.4% ,第 12天 72 % ,第 16天73% ,与对照组相比 ,其生长抑制作用具有显著性 (P<0 .0 5 ) ;AON组凋亡细胞百分率为第 4天 3.4% ,第 8天 2 7.1% ,第 12天 46 .1% ,第 16天 48.4% ,是 SON组和对照组相应时段凋亡细胞的 3.5倍以上 (P<0 .0 5 ) ;AON组 c-myb和 bcl- 2蛋白阳性表达率较对照组有显著降低 (P<0 .0 5 ) ;且 AON治疗后的脑胶质瘤中见较多炎性细胞浸润和钙化灶。结论　 c- myb癌基因有可能成为反义基因治疗恶性脑胶质瘤的优选靶点之一

Inhibitory Effect of Antisense c-myb cDNA on the Growth of Asynchronous Glioma Cells in vivo

Objective To examine the therapeutic effect of oncogene c myb antisense oligodeoxynucleotide (AON) on rat C6 glioma in vivo. Methods C6 glioma cells were implanted into the subcutis of nude mice, the animals were randomly divided into three groups (12 mice respectively) when the tumor grew about 10mm in size, and the mice with subcutaneous tumor foci were treated with sense oligodeoxynucleotide (SON), AON and normal saline.Three animals of each group were killed after treatment at 4, 8, 12 and 16 days respectively.The dynamic growth manifestations, features,histopathological changes and apoptosis of the glioma in each group were observed. Results AON supressed the growth of C6 glioma cells, the suppression rates being 66.7%,71.4%,72% and 73% at 4, 8,12,16 days respectively( P <0 05).The changes in weight were concurrent with the variations of tumor volume, the tumor weight of AON groups was significantly decreased ( P <0.05).The immunohistochemical assay showed the expression of c myb proto oncogenes was significantly decreased in AON groups ( P <0.05). The flow cytometry analysis found the apoptosis cell percentage of AON groups to be 13.4%, 27.1%, 46.1% and 48.4% at 4,8,12 and 16 days respectively, and this percentage of AON groups was about 3 5 times the apoptosis cell percentage of SON and control groups at the corresponding time. In addition, noticeable inflammatory infiltration and calcification were observed after the treatment with AON. Conclusion The above findings indicate that c myb gene might be associated with the suppression of carcinogenesis in brain glioma, and oncogene c myb might be chosen as a target for antisense gene therapy of gliomas.