9-Benzylidene-naphtho[2,3- b]thiophen-4-ones and benzylidene-9(10 H)-anthracenones as novel tubulin interacting agents with high apoptosis-inducing activity

• Published in: European journal of pharmacology Vol. 575; no. 1; pp. 34 - 45
• Main Authors: Zuse, Anne, Prinz, Helge, Müller, Klaus, Schmidt, Peter, Günther, Eckhard G., Schweizer, Frank, Prehn, Jochen H.M., Los, Marek
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2007; Elsevier
• Subjects: 9-Benzylidene-naphtho[2,3- b]thiophen-4-ones; Anthracenes - pharmacology; Antineoplastic Agents - pharmacology; Apoptosis; Apoptosis - drug effects; Benzylidene Compounds - pharmacology; Benzylidene-9(10 H)-anthracenones; Biological and medical sciences; Blotting, Western; Caspase 3 - metabolism; Chromatin - metabolism; Dose-Response Relationship, Drug; Flow Cytometry; Fluorescent Antibody Technique, Direct; G 2/M arrest; Humans; Inhibition of tubulin polymerization; Medical sciences; Microtubule; Microtubules - metabolism; Mitochondria - metabolism; Naphthalenes - pharmacology; Neuroblastoma - metabolism; Pharmacology. Drug treatments; Proto-Oncogene Proteins c-bcl-2 - metabolism; Thiophenes - pharmacology; Tubulin Modulators - pharmacology; Tumor Cells, Cultured; 9-Benzylidene-naphtho[2,3- b]thiophen-4-ones; G 2/M arrest; Microtubule; Inhibition of tubulin polymerization; Benzylidene-9(10 H)-anthracenones; Apoptosis; 9-Benzylidene-naphtho[2,3-b]thiophen-4-ones; Tubulin; Cell death; G2/M arrest; Polymerization; Cytoskeleton; Anthracene derivatives; Inhibition oftubulin polymerization; Benzylidene-9(10H)-anthracenones; 9-Benzylidene-naphtho; 3-b]thiophen-4-ones
• ISSN: 0014-2999; 1879-0712; 1879-0712
• DOI: 10.1016/j.ejphar.2007.07.050

Tubulin-binding 9-benzylidene-naphtho[2,3- b]thiophen-4-ones 1a and 1b and benzylidene-9(10 H)-anthracenone 2 were evaluated for their ability to induce cell death. We examined the effect of the molecules on cell cycle progression, organization of microtubule networks, and apoptosis induction. As determined by flow cytometry, cancer cells were predominantly arrested in metaphase with 4N DNA before cell death occurred. By using indirect immunofluorescence techniques we visualized microtubule depolymerization recognizable by short microtubule fragments scattered around the nucleus. The incubation with 1a and 2 resulted in chromatin condensation, nuclear fragmentation, and cell shrinkage, which are, among others, typical features of apoptotic cell death. Furthermore, time- and dose-dependent induction of apoptosis in SH-SY5Y cells was detected via cleavage of Ac-DEVD-AMC, a fluorigenic substrate for caspase-3. We observed a lower apoptotic activity in neuroblastoma cells overexpressing Bcl-xL, suggesting activation of the mitochondrial apoptosis pathway. Western blot analysis demonstrated that caspase-3, an apoptosis mediator, was activated in a time-dependent manner after exposure of SH-SY5Y cells to drugs 1a and 2. Taken together, the agents investigated in the present study display strong apoptosis-inducing activity and therefore show promise for the development of novel chemotherapeutics.