Two specific inhibitors of the phosphatidylinositol 3-kinase LY294002 and wortmannin up-regulate β1,4-galactosyltransferase I and thus sensitize SMMC-7721 human hepatocarcinoma cells to cycloheximide-induced apoptosis

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• 作者：Jialin Shen ; Jianhai Jiang ; Yuanyan Wei ; Lei Zhou ; Dan Liu ; Jin Zhou and Jianxin Gu
• 关键词：β1 ; 4 ; galactosyltransferase I ; Apoptosis ; Cycloheximide ; Wortmannin ; LY294002 ; SMMC ; 7721 hepatocarcinoma cells
• 刊名：Molecular and Cellular Biochemistry
• 出版年：2007
• 出版时间：October, 2007
• 年：2007
• 卷：304
• 期：1-2
• 页码：361-367
• 全文大小：362 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Biochemistry
  Medical Biochemistry
  Oncology
  Cardiology
  
• 出版者：Springer Netherlands
• ISSN：1573-4919

文摘

Previous study indicated that β1,4-galactosyltransferase I (β1,4GT1) was up-regulated by cycloheximide (CHX) and thus enhanced apoptosis induced by CHX in SMMC-7721 cells. In this study, we reported that constitutively active Akt protein (myr-Akt) inhibited CHX-induced apoptosis in SMMC-7721 cells through down-regulating β1,4GT1. However, the two PI3K inhibitors LY294002 and wortmannin treatment up-regulated β1,4GT1 through enhancing Sp1 protein expression and consequently increased CHX-induced SMMC-7721 cells apoptosis. Besides, our results suggested that β1,4GT1 and cell surface galactose residues synthesized by elevated β1,4GT1 played an important role in SMMC-7721 cells apoptosis treated with CHX and PI3K inhibitor together. Moreover, we found that CHX accentuated β1,4GT1 through down-regulating Akt expression to mediate SMMC-7721 cells apoptosis. Taken together, PI3K inhibitors LY294002 and wortmannin up-regulated β1,4GT1 and enhanced CHX-induced apoptosis in SMMC-7721 cells, which suggested that PI3K inhibitors might have therapeutic potential when combined with CHX in the treatment of hepatoma.