Jiang Jian-Dong, Denner Larry, Ling Yi-He, Li Jian-Nong, Davis Ashley, Wang Yue, Li Yan, Roboz Julia, Wang Long-Gui, Perez-Soler Roman, Marcelli Marco, Bekesi George, Holland James F
Division of Medical Oncology, Mount Sinai School of Medicine-New York University, New York 10029, USA.
Cancer Res. 2002 Nov 1;62(21):6080-8.
3-Iodoacetamido benzoyl ethyl ester (3-IAABE) is a new compound synthesized in our laboratory. The primary action of 3-IAABE is to inhibit microtubule assembly by interacting with -SH groups on tubulin. In contrast to other known microtubule disrupters, 3-IAABE caused a double blockade in the cell cycle at G(1)-S transition and in M phase. The blockade was determined by cell cycle analysis and chromosome distribution. Kinase activities of cyclin E and cyclin-dependent kinase 2 responsible for the G(1)-S transition were increased, as were the activities of mitotic cyclin B and cdc2. 3-IAABE treatment also increased p53 expression and dephosphorylated (or activated) retinoblastoma protein. Investigation of the signal transduction pathway showed that 3-IAABE induced bcl-2 phosphorylation, followed by activation of caspase-9, -3, and -6, but not caspase-8. DNA fragmentation factor and poly(ADP-ribose) polymerase, the downstream substrates of caspase-3 and -6, were cleaved after 3 h of exposure to 3-IAABE, followed by DNA fragmentation. Pretreatment of the cells with inhibitors of caspase-9, -3, or -6, respectively, inhibited the cleavage of DNA fragmentation factor and poly(ADP-ribose) polymerase and thus inhibited the onset of apoptosis. 3-IAABE showed antitumor activities in the panel of 60 National Cancer Institute human tumor cell lines with total growth inhibition in the range of 0.22-4.3 micro M for solid tumor lines and 0.025-0.22 micro M for leukemia/lymphoma cell lines. The 3-IAABU total growth inhibition of phytohemagglutinin-stimulated healthy human lymphocytes was 450-fold greater than that of leukemic cells. 3-IAABE significantly inhibited the growth of human hepatocarcinoma (BEL-7402) in nude mice by 72% in tumor volume, more strongly than did vincristine (43 percent inhibition). Besides being a novel lead for the design of new anticancer tubulin ligands, the activity of 3-IAABE in the cell cycle may also help us to understand the molecular pharmacology of microtubule-active drugs.
3-碘乙酰氨基苯甲酰乙酯（3-IAABE）是我们实验室合成的一种新化合物。3-IAABE的主要作用是通过与微管蛋白上的-SH基团相互作用来抑制微管组装。与其他已知的微管破坏剂不同，3-IAABE在细胞周期的G(1)-S期转换和M期引起双重阻滞。这种阻滞通过细胞周期分析和染色体分布来确定。负责G(1)-S期转换的细胞周期蛋白E和细胞周期蛋白依赖性激酶2的激酶活性增加，有丝分裂细胞周期蛋白B和cdc2的活性也增加。3-IAABE处理还增加了p53表达并使视网膜母细胞瘤蛋白去磷酸化（或激活）。对信号转导途径的研究表明，3-IAABE诱导bcl-2磷酸化，随后激活半胱天冬酶-9、-3和-6，但不激活半胱天冬酶-8。DNA片段化因子和聚（ADP-核糖）聚合酶，即半胱天冬酶-3和-6的下游底物，在暴露于3-IAABE 3小时后被切割，随后发生DNA片段化。分别用半胱天冬酶-9、-3或-6的抑制剂对细胞进行预处理，可抑制DNA片段化因子和聚（ADP-核糖）聚合酶的切割，从而抑制细胞凋亡的发生。3-IAABE在60种美国国立癌症研究所人类肿瘤细胞系中显示出抗肿瘤活性，对实体瘤细胞系的总生长抑制范围为0.22-4.3微摩尔，对白血病/淋巴瘤细胞系为0.025-0.22微摩尔。3-IAABU对植物血凝素刺激的健康人淋巴细胞的总生长抑制作用比对白血病细胞的抑制作用大450倍。3-IAABE显著抑制裸鼠体内人肝癌（BEL-7402）的生长，肿瘤体积缩小72%，比长春新碱（43%抑制率）的抑制作用更强。除了作为设计新型抗癌微管蛋白配体的新先导化合物外，3-IAABE在细胞周期中的活性还可能有助于我们理解微管活性药物的分子药理学。
