Effector mechanisms of norcantharidin-induced mitotic arrest and apoptosis in human hepatoma cells
Effector mechanisms of norcantharidin-induced mitotic arrest and apoptosis in human hepatoma cells
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DOI：
10.1002/ijc.10479
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发表时间：
2002-07-10
影响因子：
6.4
通讯作者：
Hsu, SL
中科院分区：
文献类型：
--
作者：
Chen, YN;Chen, JC;Hsu, SL
NCTD 是斑蝥素的去甲基化形式，具有抗肿瘤特性，目前被用作肝癌的常规抗癌药物。然而，关于 NCTD 对人类癌细胞影响的信息有限。在本研究中，NCTD 在 3 种人肝癌细胞系（HepG2、Hep3B 和 Huh-7）中抑制增殖，引起有丝分裂停滞，然后在 96 小时内进展为细胞凋亡。 NCTD处理（5μg/ml）增强了Cdc25C和p21（Cip1/Waf1）的表达，增加了这2种蛋白的磷酸化。此外，NCTD 治疗在 48 小时内诱导细胞周期蛋白 B1 相关组蛋白 H1 激酶活性较早增加，但在 72 小时时观察到细胞周期蛋白 B1 的蛋白水平和激酶活性降低了约 70%。 NCTD处理显着降低了p53蛋白的表达，但不影响Cdk1和P27 (Kip1)的表达。此外，NCTD处理还增加了Bcl-2和Bcl-X-L-的磷酸化，但不影响Bax或Bad的表达。 Bcl-2 磷酸化似乎抑制其与 Bax 的结合，因为在 NCTD 处理的 HepG2 细胞中与 Bcl-2 的免疫复合物中检测到的 Bax 较少。此外，NCTD 处理引起 caspase-9 和 caspase-3 的激活，从而导致 DNA 断裂和细胞凋亡的形态特征。用广谱 caspase 抑制剂 z-VAD-fmk 预处理可显着抑制 NCTD 诱导的 caspase-3 活性和细胞死亡。这些结果表明，p21 cip1/Waf1 和 Cdc25C 的磷酸化以及细胞周期蛋白 B1 相关激酶活性的双相调节可能有助于 NCTD 诱导的 M 期细胞周期停滞。此外，Bcl-2和BCl-X-L的p21Cip1/Waf1磷酸化增加、caspase-9和caspase-3的激活可能是NCTD诱导细胞凋亡的分子机制。 2002 年 Wilev-Liss 公司
NCTD is a demethylated form of cantharidin with antitumor properties, which is now in use as a routine anticancer drug against hepatoma. However, there is limited information on the effect of NCTD on human cancer cells. In the present study, NCTD inhibited proliferation, caused mitotic arrest, then progressed to apoptosis within 96 hr in 3 human hepatoma cell lines: HepG2, Hep3B and Huh-7. NCTD treatment (5 mug/ml) enhanced the expression of Cdc25C and p21(Cip1/Waf1), increasing the phosphorylation of these 2 proteins. In addition, NCTD treatment induced an earlier increase in cyclin B1-associated histone H1 kinase activity within 48 hr, but an approximately 70% reduction of both protein level and kinase activity of cyclin B1 was observed at 72 hr. Treatment with NCTD significantly decreased the expression of p53 protein but did not affect the expression of Cdk1 and P27 (Kip1). Moreover, NCTD treatment also increased the phosphorylation of Bcl-2 and Bcl-X-L- but did not affect the expression of Bax or Bad. Bcl-2 phosphorylation appears to inhibit its binding to Bax since less Bax was detected in immunocomplex with Bcl-2 in NCTD-treated HepG2 cells. In addition, NCTD treatment caused activation of caspase-9 and caspase-3, preceding DNA fragmentation and morphologic features of apoptosis. Pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk markedly inhibited NCTD-induced caspase-3 activity and cell death. These results suggest that phosphorylation of p21 cip1/Waf1 and Cdc25C and biphasic regulation of cyclin B l-associated kinase activity may contribute to NCTD-induced M-phase cell-cycle arrest. Furthermore, the increase of p21Cip1/Waf1 phosphorylation of Bcl-2 and BCl-X-L, activation of caspase-9 and caspase-3 may be the molecular mechanism through which NCTD induces apoptosis. 2002 Wilev-Liss, Inc.