六亚甲基二乙酰胺对MEC—1细胞凋亡及bcl—2基因表达的影响

目的：研究分化诱导剂六亚甲基二乙酰胺（hexamethylene bisacetamide,HMBA)诱导人粘液表皮样癌细胞系MEC－1细胞凋亡及凋亡相关基因bcl-2表达的影响。方法：用2mmol/LHMBA和1mg/L5-FU对培养的MEC－1细胞进行体外诱导72h后，分别采用光镜。TUNEL染色、免疫组化，原位杂交、图像分析等方法进行凋亡指数、bcl-2蛋白及mRNA表达水平的检测。结果：HMBA诱导的MEC－1细胞凋亡指数为68．5％，明显高于对照组和5－FU组（P＜0．01）；bcl-2蛋白及mRNA的表 度均显著高于其它组（P＜0．01）。结论：HMBA对人粘液表皮样癌MEC－1细胞具有明显的诱导凋亡作用，其作用机制可能与减弱了凋亡相关基因bcl-2的负调控作用有关。

Effects of hexamethylene bisacetamide on apoptosis and the expression of bcl-2 in human mucoepidermoid carcinoma cell line MEC-1

Objective: To investigate the effects of hexamethylene bisacetamide (HMBA) on apoptosis and the expression of bcl-2 in human mucoepidermoid carcinoma cell line MEC-1. Methods:MEC-1 cells were oxposed to 2 mmol/L HMBA or 1 mg/L 5 -Flourouracil (5 -FU ) for 72 hours. A poptosis index, the expression of bcl-2 protein and bcl-1 mRNA were determined by morphologic observation, terminal dUTP nick and labeling(TUNEL) stain, immunohistochemistry, in situ hybridization and image analysis. Results: Apoptosis indexes(%) in HMBA treated. 5-Fu treated and control cells were 68.5, 23.6 and 2.3 respectevely. The expression of bcl-2 protein and bcl-2 mRNA in HMBA treated cells was higher than in 5-Fu treated or the control cells(p<0. 01). Conclusion: HMBA can induce apoptosis in MEC-1 cells. The mechanism may be related to the increase of bcl-2 gene experession.