title: Denbinobin induces apoptosis by apoptosis-inducing factor releasing and DNA damage in human colorectal cancer HCT-116 cells.
abstract: Denbinobin is a phenanthraquinone derivative present in the stems of Ephemerantha lonchophylla. We showed that denbinobin induces apoptosis in human colorectal cancer cells (HCT-116) in a concentration-dependent manner. The addition of a pan-caspase inhibitor (zVAD-fmk) did not suppress the denbinobin-induced apoptotic effect, and denbinobin-induced apoptosis was not accompanied by processing of procaspase-3, -6, -7, -9, and -8. However, denbinobin triggered the translocation of the apoptosis-inducing factor (AIF) from the mitochondria into the nucleus. Small interfering RNA targeting of AIF effectively protected HCT-116 cells against denbinobin-induced apoptosis. Denbinobin treatment also caused DNA damage, activation of the p53 tumor suppressor gene, and upregulation of numerous downstream effectors (p21WAF1/CIP1, Bax, PUMA, and NOXA). A HCT-116 xenograft model demonstrated the in vivo efficacy and low toxicity of denbinobin. Taken together, our findings suggest that denbinobin induces apoptosis of human colorectal cancer HCT-116 cells via DNA damage and an AIF-mediated pathway. These results indicate that denbinobin has potential as a novel anticancer agent.
authors.affiliation: Pharmacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Sect. 1, Taipei, Taiwan.
authors.forename: Tzu-Hsuan
authors.initials: TH
authors.lastname: Chen
authors.forename: Shiow-Lin
authors.initials: SL
authors.lastname: Pan
authors.forename: Jih-Hwa
authors.initials: JH
authors.lastname: Guh
authors.forename: Chien-Chih
authors.initials: CC
authors.lastname: Chen
authors.forename: Yao-Ting
authors.initials: YT
authors.lastname: Huang
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Pai
authors.forename: Che-Ming
authors.initials: CM
authors.lastname: Teng
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000008:administration & dosage / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051033:Apoptosis Inducing Factor / Q000187:drug effects / Q000378:metabolism; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D051379:Mice; D016513:Mice, SCID; D029595:Orchidaceae / Q000737:chemistry; D010616:Phenanthrenes / Q000008:administration & dosage / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000880:Anthraquinones; D000972:Antineoplastic Agents, Phytogenic; D051033:Apoptosis Inducing Factor; D010616:Phenanthrenes; C436544:denbinobin; D020169:Caspases