title: A novel microtubule depolymerizing colchicine analogue triggers apoptosis and autophagy in HCT-116 colon cancer cells.
abstract: Colchicine is a tubulin-binding natural product isolated from Colchicum autumnale. Here we report the in vitro anticancer activity of C-ring modified semi-synthetic derivative of colchicine; N-[(7S)-1,2,3-trimethoxy-9-oxo-10-(4-phenyl-piperidin-1-yl)-5,6,7,9 tetrahydrobenzo[a]heptalen-7-yl]acetamide (4h) on colon cancer HCT-116 cell line. The compound 4h was screened for anti-proliferative activity against different human cancer cell lines and was found to exhibit higher cytotoxicity against colon cancer cell lines HCT-116 and Colo-205 with IC50 of 1 and 0.8 μM respectively. Cytotoxicity of the compound to the normal fR2 breast epithelial cells and normal HEK293 human embryonic kidney cells was evaluated in concentration and time-dependent manner to estimate its selectivity for cancer cells which showed much better selectivity than that of colchicine. Compound 4h induced cell death in HCT-116 cells by activating apoptosis and autophagy pathways. Autophagy inhibitor 3-MA blocked the production of LC3-II and reduced the cytotoxicity in response to 4h, but did not affect apoptosis, suggesting thereby that these two were independent events. Reactive oxygen species scavenger ascorbic acid pretreatment not only decreased the reactive oxygen species level but also reversed 4h induced cytotoxicity. Treatment with compound 4h depolymerized microtubules and the majority of cells arrested at the G2/M transition. Together, these data suggest that 4h has better selectivity and is a microtubule depolymerizer, which activates dual cell-death machineries, and thus, it could be a potential novel therapeutic agent in cancer therapy.
authors.affiliation: Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Jammu, India.|Academy of Scientific and Innovative Research (AcSIR), Indian Institute of Integrative Medicine (CSIR), Jammu, India.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), Indian Institute of Integrative Medicine (CSIR), Jammu, India.|Natural Products Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Jammu, India.
authors.forename: Baljinder
authors.initials: B
authors.lastname: Singh
authors.affiliation: Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Jammu, India.|Academy of Scientific and Innovative Research (AcSIR), Indian Institute of Integrative Medicine (CSIR), Jammu, India.
authors.forename: Parduman R
authors.initials: PR
authors.lastname: Sharma
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), Indian Institute of Integrative Medicine (CSIR), Jammu, India.|Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, India.
authors.forename: Sandip B
authors.initials: SB
authors.lastname: Bharate
authors.affiliation: Amity University, Lucknow, Uttar Pradesh, India.
authors.forename: Ajit K
authors.initials: AK
authors.lastname: Saxena
authors.affiliation: Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Jammu, India.|Academy of Scientific and Innovative Research (AcSIR), Indian Institute of Integrative Medicine (CSIR), Jammu, India.
authors.forename: D M
authors.initials: DM
authors.lastname: Mondhe
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003078:Colchicine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D003110:Colonic Neoplasms / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D006801:Humans; D008870:Microtubules / Q000187:drug effects* / Q000378:metabolism*; D015394:Molecular Structure; D058105:Polymerization / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D003078:Colchicine
keywords: apoptosis; autophagy; colchicine analogue; cytotoxicity; reactive oxygen species; tubulin