Norcantharidin inhibits DNA replication and induces apoptosis with the cleavage in initiation protein Cdc6 in HL-60 cells
Norcantharidin inhibits DNA replication and induces apoptosis with the cleavage in initiation protein Cdc6 in HL-60 cells
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DOI：
10.1097/00001813-200603000-00009
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发表时间：
2006-03-01
影响因子：
2.3
通讯作者：
Xian, Li-Jian
中科院分区：
文献类型：
--
作者：
Li, Jin-Long;Cai, Yu-Chen;Xian, Li-Jian
去甲斑蝥素（NCTD）是斑蝥素的去甲基化形式，目前在中国用作抗癌药物。然而，NCTD对人类癌细胞的确切抗癌机制仍然知之甚少。在本研究中，NCTD有效地抑制HL-60细胞的增殖和DNA复制。DNA复制起始蛋白Cdc 6在NCTD处理12 h后被切割。这种切割产生了相对分子量为49 kDa的截短的Cdc 6片段，并且用NCTD延长治疗导致Cdc 6的完全丧失。此外，我们发现，Cdc 6存在于未处理的HL-60细胞中的非染色质和染色质结合的组分中，并且NCTD处理导致Cdc 6在这两种组分中的裂解。用caspase-3抑制剂预处理可阻止NCTD诱导的Cdc 6裂解，表明caspase-3活性参与了该过程。此外，NCTD处理导致HL-60细胞凋亡的变化，包括颗粒状核形态，DNA梯状和sub-G1阻滞。总之，我们的研究表明，NCTD可以抑制DNA复制，并诱导凋亡和caspase-3依赖的Cdc 6切割。NCTD的抗肿瘤作用可能与Cdc 6的功能障碍密切相关，我们的报告首次提出了这一观点。
Norcantharidin (NCTD), a demethylated form of cantharidin, is currently used as an anti-cancer drug in China. However, the exact anti-cancer mechanism of NCTD on human cancer cells remains poorly understood. In the present study, NCTD inhibited proliferation and DNA replication effectively in HL-60 cells. DNA replication-initiation protein Cdc6 was cleaved after 12 h treatment with NCTD. This cleavage generated a truncated Cdc6 fragment with a relative molecular weight of 49 kDa and elongated treatment with NCTD resulted in a complete loss of Cdc6. In addition, we found that Cdc6 was present in both non-chromatin- and chromatin-bound fractions in the untreated HL-60 cells, and NCTD treatment led to the cleavage of Cdc6 in both fractions. NCTD-induced cleavage of Cdc6 was prevented by pre-treatment with caspase-3 inhibitor, suggesting the involvement of caspase-3 activity in the process. Furthermore, NCTD treatment resulted in apoptotic changes including granular nuclear morphology, DNA laddering and sub-G, arrest in HL-60 cells. In conclusion, our study reveals that NCTD can inhibit DNA replication, and induce apoptosis and caspase-3-dependent cleavage of Cdc6. The anti-cancer effect of NCTD may be closely associated with the dysfunction of Cdc6 and our report is the first to put forward this point of view.