bcl-2、c-myc基因表达在去甲二氢愈创木酸诱导人恶性胶质瘤细胞凋亡中的意义

目的：观察bcl-2、c-myc在去甲二氢愈创木酸（NDGA）诱导恶性胶质瘤细胞系SHG－44细胞凋亡中的变化及意义。方法：利用光镜和电镜观察及TUNEL法检测培养细胞凋亡的情况，用免疫组织化学、原位杂交和图像分析等方法检测bcl-2、c-myc基因mRNA和蛋白的表达水平。结果:①一定浓度的NDGA处理SHG－44细胞12－96h，均可诱导SHG－44细胞发生凋亡，且随着作用时间的延长，凋亡细胞数增加越明显；②经NDGA处理细胞后，出现SHG－44细胞bcl-2、c-myc蛋白表达水平降低，且随着作用时间的延长，这种趋势更加明显，与细胞调亡的发生密切相关；③原位杂交结果显示，NDGA处理细胞不同时间后，出现SHG－44细胞bcl-2、c-myc基因mRNA的表达水平降低，结果与免疫组化检测一致。结论：NDGA诱导SHG－44细胞的凋亡可能与其下调bcl-2、c-myc基因的表达有关，但其确切机制有待进一步深入研究。

Significance of bcl-2 and c-myc gene expression in nordihydroguaiaretic acid-induced apoptosis of a human malignant glioma cell line

Objective　To investigate the changes and their significance of bcl-2 and c-myc in nordihydroguaiaretic acid (NDGA)-induced apoptosis of human malignant glioma cell line SHG-44. Methods　The apoptosis of SHG-44 cells was observed with light and electron microscopy and TUNEL method. The expression of bcl-2 and c-myc gene was measured with immunohistochemistry, in situ hybridization and image analysis. Results ① The SHG-44 cell apoptosis was induced by NDGA at a concentration lower than 200 μmol/L in a time-dependent manner. ② The expressions of bcl-2 and c-myc gene in SHG-44 cells were decreased after the treatment of 100 μmol/L NDGA with the elapse of time, indicating a close association with cell apoptosis. ③ The expressions of bcl-2 and c-myc mRNA in SHG-44 cells were decreased after the treatment with 100μmol/L NDGA, which was apparently consistent with the immunohistochemical results. Conclusion　The NDGA-induced apoptosis in human malignant glioma cells might be related with the down-regulated expressions of bcl-2 and c-myc gene. The exact mechanism needs further research.