Cell cycle arrest, apoptosis induction and inhibition of nuclear factor kappa B activation in anti-proliferative activity of benzyl isothiocyanate against human pancreatic cancer cells
Cell cycle arrest, apoptosis induction and inhibition of nuclear factor kappa B activation in anti-proliferative activity of benzyl isothiocyanate against human pancreatic cancer cells
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DOI：
10.1093/carcin/bgh179
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发表时间：
2004-09-01
期刊：
影响因子：
4.7
通讯作者：
Singh, SV
中科院分区：
文献类型：
--
作者：
Srivastava, SK;Singh, SV
异硫氰酸苄酯（BITC）是一种十字花科植物衍生的化合物，在动物模型中已被证明可以抑制化学诱导的癌症。此外，流行病学研究提供了令人信服的证据，表明十字花科蔬菜可能具有预防癌症风险的作用。在这里，我们报道了BITC以浓度依赖的方式显著抑制人胰腺癌BxPC-3细胞的生长，其IC50类似于8 muM，该浓度可以通过饮食摄入十字花科蔬菜产生。用生长抑制浓度的BITC处理BxPC-3细胞导致G(2)/M期细胞周期阻滞，这与G(2)/M调节蛋白（包括细胞周期蛋白依赖性激酶1 （Cdk1）、细胞周期蛋白B1和细胞分裂周期25B (Cdc25B)）的蛋白水平显著下降有关。此外，bitc介导的BxPC-3细胞的生长抑制与凋亡诱导相关，其特征是Bax/Bcl-2比值增加，procaspase-3和聚（adp核糖）聚合酶（PARP）的裂解，以及细胞质组蛋白相关DNA片段的增加。有趣的是，BITC治疗引起了核因子κ b （nf - κ b）激活的抑制，而nf - κ b在人胰腺癌中是组成性激活的。Western blotting显示，暴露于BITC后，BxPC-3细胞中NF-kappaB/Rel-p65蛋白水平呈浓度依赖性降低。在bitc处理的BxPC-3细胞中，抑制亚单位kappaB （IkappaBa）蛋白水平升高与丝氨酸-32磷酸化降低相关。与这些发现一致，BITC处理导致NF-kappaB的核易位减少，这反映在NF-kappaB的dna结合能力降低上。此外，在bitc处理的BxPC-3细胞中，NF-kappaB的转录靶点cyclin D1的蛋白水平显著降低。据我们所知，这项研究是首次发表的关于抑制NF-kappaB活化作为BITC抗人胰腺癌细胞增殖活性的潜在机制的报告。
Benzyl isothiocyanate (BITC), a cruciferous vegetable-derived compound, has been shown to inhibit chemically induced cancer in animal models. Moreover, epidemiological studies have provided compelling evidence to suggest that cruciferous vegetables may be protective against cancer risk. Here, we report that BITC significantly inhibits growth of human pancreatic cancer BxPC-3 cells in a concentration-dependent manner with an IC50 of similar to8 muM, a concentration that can be generated through dietary intake of cruciferous vegetables. Treatment of BxPC-3 cells with growth suppressive concentrations of BITC resulted in G(2)/M phase cell cycle arrest that was associated with a marked decline in protein levels of G(2)/M regulatory proteins including cyclin-dependent kinase 1 (Cdk1), cyclin B1 and cell division cycle 25B (Cdc25B). Further, BITC-mediated growth inhibition of BxPC-3 cells correlated with apoptosis induction that was characterized by an increase in Bax/Bcl-2 ratio, cleavage of procaspase-3 and poly(ADP-ribose)polymerase (PARP), and an increase in cytoplasmic histone-associated DNA fragmentation. Interestingly, BITC treatment caused inhibition of nuclear factor kappaB (NF-kappaB) activation, which is constitutively activated in human pancreatic cancer. Western blotting revealed concentration-dependent decrease in NF-kappaB/Rel-p65 protein level in BxPC-3 cells upon exposure to BITC. An increase in protein level of inhibitory subunit kappaB (IkappaBa) in association with reduced serine-32 phosphorylation was also observed in BITC-treated BxPC-3 cells. Consistent with these findings, BITC treatment caused a decrease in nuclear translocation of NF-kappaB as reflected by reduced DNA-binding capacity of NF-kappaB. Furthermore, the protein level of cyclin D1, a transcriptional target of NF-kappaB, was reduced significantly in BITC-treated BxPC-3 cells. To the best of our knowledge, this study is the first published report to implicate suppression of NF-kappaB activation as a potential mechanism for anti-proliferative activity of BITC against human pancreatic cancer cells.