Pharmacological inhibition or small interfering RNA targeting acid ceramidase sensitizes hepatoma cells to chemotherapy and reduces tumor growth in vivo
Pharmacological inhibition or small interfering RNA targeting acid ceramidase sensitizes hepatoma cells to chemotherapy and reduces tumor growth in vivo
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DOI：
10.1038/sj.onc.1209834
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发表时间：
2007-02-08
期刊：
影响因子：
8
通讯作者：
Fernandez-Checa, J. C.
中科院分区：
文献类型：
--
作者：
Morales, A.;Paris, R.;Fernandez-Checa, J. C.
神经酰胺酶（CD酶）通过促进神经酰胺转化为1-磷酸鞘氨醇（S1 P）在癌症治疗中发挥关键作用，但其在肝癌发生中的作用尚不清楚。在这里，我们报告道诺霉素（DNR）激活酸性CD酶转录后在建立的人（HepG 2细胞）或小鼠（Hepa 1c 1c 7）肝癌细胞系，以及在原代细胞从小鼠肝肿瘤，但不是在培养的小鼠肝细胞。与单独使用DNR相比，通过小干扰RNA（siRNA）或N-油酰乙醇胺（NOE）的药理学抑制来沉默酸性CD酶增强了神经酰胺与S1 P的平衡，使肝癌细胞（HepG 2，Hep-3B，SK-Hep和Hepa 1c 1c 7）对DNR诱导的细胞死亡敏感。DNR加NOE或酸性CD酶siRNA诱导的细胞死亡之前，线粒体超微结构的变化，刺激活性氧的产生，释放Smac/DIABLO和细胞色素c和caspase-3激活。此外，靶向酸性CD酶的体内siRNA治疗减少了HepG 2细胞的肝肿瘤异种移植物中的肿瘤生长并增强了DNR治疗。因此，酸性CD酶促进肝癌的发生，其拮抗作用可能是治疗肝癌的一个有前途的策略。
Ceramidases (CDases) play a key role in cancer therapy through enhanced conversion of ceramide into sphingosine 1-phosphate (S1P), but their involvement in hepatocarcinogenesis is unknown. Here, we report that daunorubicin (DNR) activated acid CDase post-transcriptionally in established human (HepG2 cells) or mouse (Hepa1c1c7) hepatoma cell lines as well as in primary cells from murine liver tumors, but not in cultured mouse hepatocytes. Acid CDase silencing by small interfering RNA (siRNA) or pharmacological inhibition with N-oleoylethanolamine (NOE) enhanced the ceramide to S1P balance compared to DNR alone, sensitizing hepatoma cells (HepG2, Hep-3B, SK-Hep and Hepa1c1c7) to DNR-induced cell death. DNR plus NOE or acid CDase siRNA-induced cell death was preceded by ultrastructural changes in mitochondria, stimulation of reactive oxygen species generation, release of Smac/DIABLO and cytochrome c and caspase-3 activation. In addition, in vivo siRNA treatment targeting acid CDase reduced tumor growth in liver tumor xenografts of HepG2 cells and enhanced DNR therapy. Thus, acid CDase promotes hepatocarcinogenesis and its antagonism may be a promising strategy in the treatment of liver cancer.