RNAi-mediated knockdown of aldehyde dehydrogenase class-1A1 and class-3A1 is specific and reveals that each contributes equally to the resistance against 4-hydroperoxycyclophosphamide
RNAi-mediated knockdown of aldehyde dehydrogenase class-1A1 and class-3A1 is specific and reveals that each contributes equally to the resistance against 4-hydroperoxycyclophosphamide
复制标题
DOI：
10.1007/s00280-006-0233-6
复制
发表时间：
2007-01-01
影响因子：
3
通讯作者：
Zucali, James R.
中科院分区：
文献类型：
--
作者：
Moreb, Jan S.;Muhoczy, Dagmara;Zucali, James R.
目的：醛脱氢酶1A 1类（ALDH 1A 1）和3A 1类（ALDH 3A 1）与对环磷酰胺（CP）及其衍生物的耐药性有关。我们以前曾报道下调这些酶的全反式维甲酸（ATRA）。研究方法：在本研究中，我们使用siRNA双链体以及逆转录病毒表达的siRNA敲除A549肺癌细胞系中的一种或两种酶，以研究每种酶在介导耐药性中的作用以及加入ATRA的效果。结果如下：结果表明，可以实现每种酶的显著和特异性敲低，并且每种酶对细胞对CP的活性衍生物4-氢过氧环磷酰胺（4-HC）的抗性的贡献相似。当两种酶都被抑制时，可以看到额外的效果。ATRA的加入还表现出对ALDH活性的额外抑制作用，并且当加入针对其中一种酶的单一siRNA时，4-HC毒性增加。另一方面，当加入到针对两种酶的siRNA组合中时，ATRA对ALDH酶活性具有最小且不显著的额外抑制作用，但仍增加4-HC毒性，超过RNAi介导的两种酶一起抑制所见。结论：我们的结论是，这两种酶，ALDH 1A 1和ALDH 3A 1将需要被阻断，以达到最高的敏感性4-HC。此外，ATRA增加4-HC毒性，甚至当加入到针对两种酶的siRNA组合中时，因此表明ATRA可以增加药物毒性的其他机制。
Purpose: Aldehyde dehydrogenases class-1A1 (ALDH1A1) and class-3A1 (ALDH3A1) have been associated with resistance to cyclophosphamide (CP) and its derivatives. We have previously reported the downregulation of these enzymes by all-trans retinoic acid (ATRA). Methods: In this study, we used siRNA duplexes as well as retrovirally expressed siRNA to knockdown one or both enzymes together in A549 lung cancer cell line in order to investigate the role of each one in mediating the resistance and the effect of the addition of ATRA. Results: The results show that significant and specific knockdown of each enzyme can be achieved and that each one contributes similarly to cell resistance to 4-hydroperoxycyclophosphamide (4-HC), an active derivative of CP. Added effects were seen when both enzymes were inhibited. The addition of ATRA also exhibited additional inhibitory effects on ALDH activity and increased 4-HC toxicity when added to single siRNA aimed at one of the enzymes. On the other hand, ATRA had minimal and insignificant additional inhibitory effects on ALDH enzyme activity when added to a combination of siRNAs against both enzymes, but still increased 4-HC toxicity beyond that seen with RNAi-mediated inhibition of both enzymes together. Conclusions: We conclude that both enzymes, ALDH1A1 and ALDH3A1 will need to be blocked in order to achieve the highest sensitivity to 4-HC. Furthermore, ATRA increases 4-HC toxicity even when added to a combination of siRNAs against both enzymes, thus suggesting additional mechanisms by which ATRA can increase drug toxicity.