title: α-Carboline derivative TJY-16 inhibits tumor growth by inducing G2/M cell cycle arrest in glioma cells.
abstract: BACKGROUND
  Glioblastoma multiforme (GBM) is the most lethal primary brain tumors which remains difficult to cure despite advances in surgery, radiotherapy and chemotherapy. Therefore, the development of new drug is urgently needed. α-carboline derivatives were usually isolated from marine animals such as Britannia marine tunicate Dendrodoa grossularia and Indonesian ascidian Polycarpa aurata. In this study, we have synthesized several α-carboline compounds and examined their anti-glioma activities.
  
  
  RESULTS
  We report that among α-carboline derivatives TJY-16 (6-acetyl-9-(3,4,5-trimethoxybenzyl)-9H-pyrido[2,3-b] indole) is the most potent α-carboline analog to induce glioma cell death with IC50 value of around 50 nM. TJY-16 decreased cell viability of glioma cells in a concentration- and time-dependent manner. Trypan blue exclusion assay showed that the reduction of cell viability was due to both cell growth inhibition and cell death. Flow cytometric analysis showed that TJY-16 induced G2/M cell cycle arrest followed by induction of sub-G1 phase. Hoechst staining detected the apoptotic features such as nuclear shrinkage and DNA condensation. Western blot analysis showed the increased level of cleaved caspase-3. The activation of caspase-8 and depolarization of mitochondrial membrane potential (ΔΨm) indicated that both extrinsic and intrinsic apoptotic pathways were involved in TJY-16-induced apoptosis. TJY-16 effectively inhibited tumor growth and induced caspase-3 activation in the xenograft tumor model of U87 glioma cells.
  
  
  CONCLUSIONS
  Our results suggest that TJY-16 may kill glioma cells by inducing G2/M cell cycle arrest followed by apoptosis. Thus, TJY-16 is a promising agent for the treatment of malignant gliomas.
authors.affiliation: Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Hsiao-Chieh
authors.initials: HC
authors.lastname: Huang
authors.affiliation: Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Kuo-Su
authors.initials: KS
authors.lastname: Hua
authors.affiliation: Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Hui-Chi
authors.initials: HC
authors.lastname: Hung
authors.affiliation: Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan.
authors.forename: Jui-Ying
authors.initials: JY
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan.
authors.forename: Sheng-Chu
authors.initials: SC
authors.lastname: Kuo
authors.affiliation: Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan. ljhuang@mail.cmu.edu.tw.
authors.forename: Li-Jiau
authors.initials: LJ
authors.lastname: Huang
authors.affiliation: Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan. powu@mail.ncku.edu.tw.
authors.forename: Po-Wu
authors.initials: PW
authors.lastname: Gean
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D004273:DNA, Neoplasm / Q000378:metabolism*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D005910:Glioma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D006801:Humans; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects*; D014561:Urochordata / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D004273:DNA, Neoplasm