全反式维甲酸抑制反义N-乙酰氨基葡萄糖转移酶V转染的SMMC7721肝癌细胞蛋白激酶B的表达  

Down-regulation of protein kinase B (PKB) by all-trans retinoic acid(ATRA) treated SMMC7721 cell transfected with antisenseN-Acetylglucosaminyltransferase V cDNA

作　　者：陈舌[1] 黄传新[1] 殷祥雷[1] 陈惠黎[1] 申宗侯[1] 

机构地区：[1]复旦大学医学院生物化学教研室,上海200032

出　　处：《肿瘤》2003年第1期35-38,共4页Tumor

基　　金：国家自然科学基金项目(39630080;39870619);上海市教委重点项目基金(B990806)

摘　　要：目的探讨全反式维甲酸(ATRA)诱导反义N-乙酰氨基葡萄糖转移酶V转染的SMMC 7721肝癌细胞(简称AS—GnT—V/7721)凋亡机制。方法用Hoechst染色检测ATRA诱导细胞凋亡情况,并应用Northern Blot和Western Blot检测ATRA诱导AS—GnT-V/ 7721细胞凋亡过程中bcl-2及蛋白激酶B(PKB)的表达。结果Hoechst 33258染色结果显示ATRA处理AS—GnT—V/7721细胞24h后,细胞发生凋亡。Western Blot检测发现,ATRA处理AS-GnT—V/7721细胞不改变bcl-2的表达,但抑制PKB蛋白表达。ATRA处理AS-GnT—V/7721细胞24h后PKB蛋白即明显降低(约为原来的32％),处理48h后PKB蛋白几乎检测不到。Northern blot检测发现,ATRA处理AS-GnT-V/7721细胞12h,PKB mRNA即有所下降,24h时PKB mRNA约为原来的48％,处理48h,PKB mRNA减少至原来的15％。而ATRA处理对照细胞,bcl-2及PKB表达均不变。结论ATRA诱导AS-GnT-V/7721细胞凋亡过程中PKB的表达下降,而bcl-2表达不变。提示,ATRA诱导AS—GnT-V/7721细胞凋亡可能是由于抑制PKB表达,而与bcl-2无关。Objective To investigate the mechanism of ATRA induced apoptosis of SMMC 7721 cell transfected with antisense N-acetylglucosaminyltransferase V cDNA. Methods Cells were examined by Hoechst 33258 stain to detect the apoptosis, then Western blot and Northern blot were used to detect bcl-2 and PKB expression in AS-GnT-V/7721 cells treated with ATRA. Results The AS-GnT-v/7721 cells treated with ATRA for 24 hours showed peripheral accumulation of nuclear chromatin by Hoechst 33258 stain. Western blot experiments showed that the timed treatment of 80μmol/L ATRA did not alter the bcl-2 protein level in the transfected cells as well as control cells. However, the levels of PKB in AS-GnT-V/7721 cells exhibited divergence from the levels of PKB in SMMC 7721 cells at 24 hours, at which time PKB mRNA was reduced by about 48%, while PKB protein was reduced by about 32%. At 48 hours the levels of PKB exhibited the greatest divergence from the levels of PKB in SMMC 7721, at which time PKB mRNA was reduced by about 15%, while PKB protein was almost undetectable. Conclusion ATRA-induced apoptosis was accompanied by down-regulation of PKB. ATRA had no effect on the levels of bcl-2. These findings suggest that down-regulation of PKB maybe involves in cell death with apoptosis when AS-GnT-V/7721 cells are exposed to ATRA, but ATRA-induced apoptosis is not the result from down-regulation of bcl-2.

关 键 词：肝癌 反义N-乙酰氨基葡萄糖转移酶V 全反式维甲酸 蛋白激酶B BCL-2 基因表达 

分 类 号：R735.7[医药卫生—肿瘤]