Double blockade of cell cycle at G1-S transition and M phase by 3-iodoacetamido benzoyl ethyl ester, a new type of tubulin ligand

Jian Dong Jiang, Larry Denner, Yi He Ling, Jian Nong Li, Ashley Davis, Yue Wang, Yan Li, Julia Roboz, Long Gui Wang, Roman Perez-Soler, Marco Marcelli, George Bekesi, James F. Holland

Research output: Contribution to journalArticle

31 Scopus citations


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 G1-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 G1-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 μM for solid tumor lines and 0.025-0.22 μM 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% 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.

Original languageEnglish (US)
Pages (from-to)6080-6088
Number of pages9
JournalCancer Research
Issue number21
Publication statusPublished - Jan 1 2002


ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Jiang, J. D., Denner, L., Ling, Y. H., Li, J. N., Davis, A., Wang, Y., ... Holland, J. F. (2002). Double blockade of cell cycle at G1-S transition and M phase by 3-iodoacetamido benzoyl ethyl ester, a new type of tubulin ligand. Cancer Research, 62(21), 6080-6088.