Inhibitors of histone deacetylase (HDAC) restore the p53 pathway in neuroblastoma cells
Inhibitors of histone deacetylase (HDAC) restore the p53 pathway in neuroblastoma cells
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DOI：
10.1038/sj.bjp.0707608
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发表时间：
2008-02-01
影响因子：
7.3
通讯作者：
Canonico, P. L.
中科院分区：
文献类型：
--
作者：
Condorelli, F.;Gnemmi, I.;Canonico, P. L.
背景和目的：组蛋白脱乙酰酶（HDAC）抑制剂正在成为一类有前景的抗癌药物，但肿瘤细胞中转录的一般失调并不能完全解释其治疗效果。在本研究中，我们评估了 HDAC 抑制剂影响神经母细胞瘤活力的替代分子机制。实验方法：通过 MTT 测定评估 HDAC 抑制剂对 I 型 SK-N-BE 和 N 型 NB SH-SY5Y 神经母细胞瘤细胞系存活的影响。通过蛋白质印迹、共聚焦显微镜和细胞荧光测定法检查了导致这一现象的分子途径。通过 RT-PCR 半定量评估凋亡介质的 mRNA 水平。在 EMSA 实验中评估了肿瘤抑制因子 p53 反式活性。还在受到基于质粒的 p53 干扰 (p53i) 的细胞中研究了 HDAC 抑制剂。主要结果：HDAC 抑制剂通过线粒体凋亡途径并招募 Bcl-2 家族成员来诱导细胞死亡。 Bcl-2 过度表达使神经母细胞瘤细胞对 HDAC 抑制剂治疗产生抵抗。低浓度的 HDAC 抑制剂 (0.9mM) 导致 G2 细胞周期停滞和 p21/Waf1/Cip1 蛋白的显着上调。 HDAC 抑制剂还通过过度乙酰化和核重新定位激活 p53 蛋白，而不影响其蛋白表达。因此，HDAC 抑制剂诱导的细胞杀伤和 p21/Waf1/Cip1 上调在 p53i 细胞中受到损害。 结论和意义：在神经母细胞瘤细胞中，HDAC 抑制剂可以通过其过度乙酰化和核迁移恢复 p53 肿瘤抑制功能，从而克服对经典化疗药物的耐药性，这些事件通常在神经母细胞瘤细胞中受损。 这样的肿瘤。在神经母细胞瘤细胞中，在缺乏功能性 p53 的情况下，HDAC 抑制剂无法诱导 p21/Waf1/Cip1。
Background and purpose: Inhibitors of histone deacetylase (HDAC) are emerging as a promising class of anti- cancer drugs, but a generic deregulation of transcription in neoplastic cells cannot fully explain their therapeutic effects. In this study we evaluated alternative molecular mechanisms by which HDAC inhibitors could affect neuroblastoma viability.Experimental approach: Effects of HDAC inhibitors on survival of the I-type SK-N-BE and the N-type NB SH-SY5Y neuroblastoma cell lines were assessed by the MTT assay. Molecular pathways leading to this were examined by western blot, confocal microscopy and cytofluorometry. The mRNA levels of apoptotic mediators were assessed semi-quantitatively by RT-PCR. Tumour-suppressor p53 trans activity was assessed in EMSA experiments. HDAC inhibitors were also studied in cells subjected to plasmid-based p53 interference (p53i).Key results: HDAC inhibitors induced cell death via the mitochondrial pathway of apoptosis with recruitment of Bcl-2 family members. Bcl-2 overexpression rendered neuroblastoma cells resistant to HDAC inhibitor treatment. Low concentrations of HDAC inhibitors (0.9mM) caused a G2 cell-cycle arrest and a marked upregulation of the p21/Waf1/Cip1 protein. HDAC inhibitors also activate the p53 protein via hyper-acetylation and nuclear re-localization, without affecting its protein expression. Accordingly, HDAC inhibitor-induced cell-killing and p21/Waf1/Cip1 upregulation is impaired in p53i-cells.Conclusions and implications: In neuroblastoma cells, HDAC inhibitors may overcome the resistance to classical chemotherapeutic drugs by restoring the p53 tumour-repressor function via its hyper-acetylation and nuclear migration, events usually impaired in such tumours. In neuroblastoma cells, HDAC inhibitors are not able to induce p21/Waf1/Cip1 in the absence of a functional p53.