title: Novel piperazine-based compounds inhibit microtubule dynamics and sensitize colon cancer cells to tumor necrosis factor-induced apoptosis.
abstract: We recently identified a series of mitotically acting piperazine-based compounds that potently increase the sensitivity of colon cancer cells to apoptotic ligands. Here we describe a structure-activity relationship study on this compound class and identify a highly active derivative ((4-(3-chlorophenyl)piperazin-1-yl)(2-ethoxyphenyl)methanone), referred to as AK301, the activity of which is governed by the positioning of functional groups on the phenyl and benzoyl rings. AK301 induced mitotic arrest in HT29 human colon cancer cells with an ED50 of ≈115 nm. Although AK301 inhibited growth of normal lung fibroblast cells, mitotic arrest was more pronounced in the colon cancer cells (50% versus 10%). Cells arrested by AK301 showed the formation of multiple microtubule organizing centers with Aurora kinase A and γ-tubulin. Employing in vitro and in vivo assays, tubulin polymerization was found to be slowed (but not abolished) by AK301. In silico molecular docking suggests that AK301 binds to the colchicine-binding domain on β-tubulin, but in a novel orientation. Cells arrested by AK301 expressed elevated levels of TNFR1 on their surface and more readily activated caspases-8, -9, and -3 in the presence of TNF. Relative to other microtubule destabilizers, AK301 was the most active TNF-sensitizing agent and also stimulated Fas- and TRAIL-induced apoptosis. In summary, we report a new class of mitosis-targeting agents that effectively sensitizes cancer cells to apoptotic ligands. These compounds should help illuminate the role of microtubules in regulating apoptotic ligand sensitivity and may ultimately be useful for developing agents that augment the anti-cancer activities of the immune response.
authors: From the Departments of Molecular and Cell Biology and.
authors: Avijeet
authors: A
authors: Chopra
authors: Amy
authors: A
authors: Anderson
authors: Charles
authors: C
authors: Giardina
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D007249:Inflammation / Q000473:pathology / Q000503:physiopathology; D008024:Ligands; D008870:Microtubules / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects / Q000502:physiology; D008958:Models, Molecular; D010879:Piperazines / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: C587628:(4-(3-chlorophenyl)piperazin-1-yl)(2-ethoxyphenyl)methanone; D008024:Ligands; D010879:Piperazines; D014409:Tumor Necrosis Factor-alpha; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9
keywords: Apoptosis; Colon Cancer; Inflammation; Microtubule Inhibitors; Mitosis; Molecular Docking; Small Molecules