title: CXI-benzo-84 reversibly binds to tubulin at colchicine site and induces apoptosis in cancer cells.
abstract: Here, we have discovered CXI-benzo-84 as a potential anticancer agent from a library of benzimidazole derivatives using cell based screening strategy. CXI-benzo-84 inhibited cell cycle progression in metaphase stage of mitosis and accumulated spindle assembly checkpoint proteins Mad2 and BubR1 on kinetochores, which subsequently activated apoptotic cell death in cancer cells. CXI-benzo-84 depolymerized both interphase and mitotic microtubules, perturbed EB1 binding to microtubules and inhibited the assembly and GTPase activity of tubulin in vitro. CXI-benzo-84 bound to tubulin at a single binding site with a dissociation constant of 1.2±0.2μM. Competition experiments and molecular docking suggested that CXI-benzo-84 binds to tubulin at the colchicine-site. Further, computational analysis provided a significant insight on the binding site of CXI-benzo-84 on tubulin. In addition to its potential use in cancer chemotherapy, CXI-benzo-84 may also be useful to screen colchicine-site agents and to understand the colchicine binding site on tubulin.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
authors.forename: Ankit
authors.initials: A
authors.lastname: Rai
authors.forename: Tilak Kumar
authors.initials: TK
authors.lastname: Gupta
authors.forename: Sudarshan
authors.initials: S
authors.lastname: Kini
authors.forename: Ambarish
authors.initials: A
authors.lastname: Kunwar
authors.forename: Avadhesha
authors.initials: A
authors.lastname: Surolia
authors.forename: Dulal
authors.initials: D
authors.lastname: Panda
mesh_terms: D000813:Anilides / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001562:Benzimidazoles / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites / Q000502:physiology; D045744:Cell Line, Tumor; D003078:Colchicine / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000813:Anilides; D000970:Antineoplastic Agents; D001562:Benzimidazoles; C583573:N-(2-(piperidin-1-yl)phenyl)-2-(thiophen-2-yl)-1H-benzo(d)imidazole-4-carboxamide; D014404:Tubulin; D003078:Colchicine
keywords: (N-(2-(piperidin-1-yl)phenyl)-2-(thiophen-2-yl)-1H-benzo[d]imidazole-4-carboxamide); Anticancer drug; Apoptosis; Benzimidazole; CXI-benzo-84; Cell cycle; Checkpoint proteins; DAMA-colchicine; DMSO; EGTA; GTP; Microtubule assembly dynamics; N-deacetyl-N-(2-mercaptoacetyl) colchicine; PBS; PI; PIPES; SRB; TCA; dimethyl sulfoxide; ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid; guanosine-5′-triphosphate; phosphate buffered saline; piperazine-N,N′-bis(2-ethanesulfonic acid); propidium iodide; sulforhodamine B; trichloro acetic acid