title: Tangeretin derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone induces G2/M arrest, apoptosis and autophagy in human non-small cell lung cancer cells in vitro and in vivo.
abstract: Tangeretin, a major phytochemicals in tangerine peels--an important Chinese herb, has been found to have anti-carcinogenic properties. To improve bioavailability and increase potency of tangeretin, its derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone (5-AcTMF), has been synthesized and shown potent inhibition of proliferation activity against human breast and leukemia cancer cell lines. In this study, we have further investigated the anticancer effects of 5-AcTMF on CL1-5 non-small cell lung cancer cells (NSCLC) both in vitro and in vivo and demonstrated that 5-AcTMF effectively inhibited cancer cell proliferation, induced G2/M-phase arrest associated with cdc2 and CDC25c and increased in the apoptotic cells associated with caspase activation, down regulation of Bcl-2, XIAP and Survivn, inducing release of cytochrome c into the cytosol and disruption of mitochondrial membrane potential. We also found that 5-AcTMF treatment of CL1-5 activated autophagy, indicated by triggered autophagosome formation and increased LC3-II levels and formation of LC3 puncta. Moreover, we also found that 5-AcTMF lowered phophoatidylinositol 3-kinase/AKT/mTOR signaling pathway. Over-expression of AKT by AKT cDNA transfection decreased 5-AcTMF mediated apoptosis and autophagy, supporting the induction of apoptosis and autophagy by inhibition of AKT pathway. In an animal study, 5-AcTMF effectively delayed tumor growth in a nude mouse model of CL1-5 xenografts without observed adverse effect. Immunohistochemistry Analysis indicated that 5-AcTMF induced CL1-5 cell apoptosis and autophagy in vivo. Taken together, these data demonstrate that 5-AcTMF is a novel small molecule agent that can inhibit NSCLC cell proliferation, and induce G(2)/M phase arrest and via the mitochondrial apoptotic pathway and autophagy.
authors.affiliation: a Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung-Hsing University , Taichung , Taiwan.
authors.forename: Yi Rong
authors.initials: YR
authors.lastname: Li
authors.affiliation: b Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University , Hubei , China.
authors.forename: Shiming
authors.initials: S
authors.lastname: Li
authors.affiliation: c Department of Food Science , Rutgers University , New Brunswick , NJ , USA.
authors.forename: Chi-Tang
authors.initials: CT
authors.lastname: Ho
authors.affiliation: a Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung-Hsing University , Taichung , Taiwan.
authors.forename: Ya-Han
authors.initials: YH
authors.lastname: Chang
authors.affiliation: a Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung-Hsing University , Taichung , Taiwan.|d Tungs' Taichung MetroHarbor Hospital , Taichung , Taiwan.
authors.forename: Kok-Tong
authors.initials: KT
authors.lastname: Tan
authors.affiliation: e Institute of Bioinformatics and Structural Biology and Department of Medical Sciences, National Tsing Hua University , Hsinchu , Taiwan.
authors.forename: Ting-Wen
authors.initials: TW
authors.lastname: Chung
authors.affiliation: f Division of Thoracic Surgery, Department of Surgery, Changhua Christian Hospital and Institute of Medicine, Chung Shan Medical University , Taichung , Taiwan.
authors.forename: Bing-Yen
authors.initials: BY
authors.lastname: Wang
authors.affiliation: g Department of Food Science , National Pingtung University of Science and Technology , Pingtung , Taiwan.
authors.forename: Yu-Kuo
authors.initials: YK
authors.lastname: Chen
authors.affiliation: a Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung-Hsing University , Taichung , Taiwan.
authors.forename: Chi-Chen
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D047309:Flavones / Q000008:administration & dosage* / Q000138:chemical synthesis / Q000737:chemistry; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis; D023041:Xenograft Model Antitumor Assays
chemical_list: D047309:Flavones; D051057:Proto-Oncogene Proteins c-akt; C059006:tangeretin; C043562:flavone
keywords: 5-Acetyloxy-6,7,8,4′-tetramethoxyflavone; AKT; apoptosis; autophagy; G2/M arrest; non-small cell lung cancer cell