Sirtinol, a class III HDAC inhibitor, induces apoptotic and autophagic cell death in MCF-7 human breast cancer cells
Sirtinol, a class III HDAC inhibitor, induces apoptotic and autophagic cell death in MCF-7 human breast cancer cells
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DOI：
10.3892/ijo.2012.1534
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发表时间：
2012-09-01
影响因子：
5.2
通讯作者：
Kim, Hyung Sik
中科院分区：
文献类型：
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作者：
Wang, Jing;Kim, Tae Hyung;Kim, Hyung Sik
Sirtuins （SIRTs）是依赖NAD（+）的III类组蛋白去乙酰化酶（hdac），在细胞分裂、存活和衰老的调控中发挥重要作用。尽管许多有效的SIRT抑制剂已经被开发出来，但人们对其抗癌活性的具体机制知之甚少。在本研究中，我们研究了sirtinol （SIRT抑制剂）对MCF-7人乳腺癌细胞的抗癌作用。观察细胞凋亡和自噬细胞死亡情况。Sirtinol显著抑制MCF-7细胞的增殖，且呈浓度依赖性。sirtinol在MCF-7细胞中的IC50值分别为48.6 μ M （24 h）和43.5 μ M （48 h）。正如预期的那样，sirtinol显著增加了p53的乙酰化，而p53是SIRT1/2的靶标。流式细胞术分析显示，sirtinol显著增加了细胞周期的G1期。在sirtinol处理的MCF-7细胞中，观察到Bax上调、Bcl-2下调和细胞色素c释放到细胞质中被认为是凋亡细胞死亡的机制。Annexin V-FITC法证实sirtinol诱导凋亡细胞死亡。此外，sirtinol处理后，MCF-7细胞中自噬相关分子LC3-II的表达显著增加。吖啶橙和单胺尸胺（MDC）染色证实自噬细胞死亡。值得注意的是，3-甲基ladeninc （3-MA）预处理增加了sirtinol诱导的MCF-7细胞的细胞毒性，这与阻断自噬细胞死亡和增加凋亡细胞死亡有关。基于我们的研究结果，SIRT1/2表达下调可能在乳腺癌细胞死亡的调控中发挥重要作用；因此，SIRT1/2可能是癌症治疗的一个新的分子靶点，这些发现可能为今后靶向SIRT1/2治疗癌症提供分子基础。
Sirtuins (SIRTs), NAD(+)-dependent class III histone deacetylases (HDACs), play an important role in the regulation of cell division, survival and senescence. Although a number of effective SIRT inhibitors have been developed, little is known about the specific mechanisms of their anticancer activity. In this study, we investigated the anticancer effects of sirtinol, a SIRT inhibitor, on MCF-7 human breast cancer cells. Apoptotic and autophagic cell death were measured. Sirtinol significantly inhibited the proliferation of MCF-7 cells in a concentration-dependent manner. The IC50 values of sirtinol were 48.6 mu M (24 h) and 43.5 mu M (48 h) in MCF-7 cells. As expected, sirtinol significantly increased the acetylation of p53, which has been reported to be a target of SIRT1/2. Flow cytometry analysis revealed that sirtinol significantly increased the G1 phase of the cell cycle. The upregulation of Bax, downregulation of Bcl-2 and cytochrome c release into the cytoplasm, which are considered as mechanisms of apoptotic cell death, were observed in the MCF-7 cells treated with sirtinol. The Annexin V-FITC assay was used to confirm sirtinol-induced apoptotic cell death. Furthermore, the expression of LC3-II, an autophagy-related molecule, was significantly increased in MCF-7 cells after sirtinol treatment. Autophagic cell death was confirmed by acridine orange and monodansylcadaverine (MDC) staining. Of note, pre-treatment with 3-methyladeninc (3-MA) increased the sirtinol-induced MCF-7 cell cytotoxicity, which is associated with blocking autophagic cell death and increasing apoptotic cell death. Based on our results, the downregulation of SIRT1/2 expression may play an important role in the regulation of breast cancer cell death; thus, SIRT1/2 may be a novel molecular target for cancer therapy and these findings may provide a molecular basis for targeting SIRT1/2 in future cancer therapy.