Hu Wan-Ping, Tsai Feng-Yuan, Yu Hsin-Su, Sung Ping-Jyun, Chang Long-Sen, Wang Jeh-Jeng
Faculty of Biotechnology, College of Life Science, Department of Dermatology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chem Res Toxicol. 2008 Jul;21(7):1330-6. doi: 10.1021/tx700394h. Epub 2008 May 31.
DC-81, an antitumor antibiotic produced by Streptomyces species, belongs to the pyrrolo[2,1- c][1,4]benzodiazepine (PBD) family, which are potent inhibitors of nucleic acid synthesis. We previously reported an efficient synthesis of PBD hybrids linked with indole carboxylates. Recently, we have also shown that a PBD hybrid (IN6CPBD) agent can activate the apoptotic pathway mediated by mitochondria. In this study, we will examine the transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) that functionally regulate cell proliferation, transformation, and apoptosis. To investigate the IN6CPBD-induced alterations in NF-kappaB and AP-1 activity that involve cell cycle regulation, we exposed human melanoma A375 cells to different concentrations of IN6CPBD. Our data revealed that treatment of A375 cells with IN6CPBD resulted in a marked loss of cells from the G2/M phase of the cell cycle and an increase in Ca (2+) and cAMP and promoted phosphorylation of Jun N-terminal kinase (JNK) expression. By using the luciferase reporter assay, the NF-kappaB activities were decreased; however, AP-1 activity was further enhanced after A375 cells were treated with graded concentrations of IN6CPBD. Blockade of NF-kappaB or JNK activity further enhanced caspase-3 substrate PARP cleavage and subsequent apoptotic cell death.
DC-81是一种由链霉菌属产生的抗肿瘤抗生素，属于吡咯并[2,1-c][1,4]苯并二氮杂卓（PBD）家族，是核酸合成的有效抑制剂。我们之前报道了一种与吲哚羧酸盐相连的PBD杂合物的高效合成方法。最近，我们还表明一种PBD杂合物（IN6CPBD）试剂可以激活由线粒体介导的凋亡途径。在本研究中，我们将检测在功能上调节细胞增殖、转化和凋亡的转录因子核因子-κB（NF-κB）和激活蛋白-1（AP-1）。为了研究IN6CPBD诱导的涉及细胞周期调节的NF-κB和AP-1活性的改变，我们将人黑色素瘤A375细胞暴露于不同浓度的IN6CPBD中。我们的数据显示，用IN6CPBD处理A375细胞导致细胞周期G2/M期的细胞显著减少，Ca（2+）和cAMP增加，并促进Jun N端激酶（JNK）表达的磷酸化。通过荧光素酶报告基因检测，NF-κB活性降低；然而，用不同浓度的IN6CPBD处理A375细胞后，AP-1活性进一步增强。阻断NF-κB或JNK活性进一步增强了半胱天冬酶-3底物PARP的切割以及随后的凋亡细胞死亡。
