title: Isoliquiritigenin as a cause of DNA damage and inhibitor of ataxia-telangiectasia mutated expression leading to G2/M phase arrest and apoptosis in oral squamous cell carcinoma.
abstract: Isoliquiritigenin (ISL), a natural compound extracted from licorice, has chemopreventive and antitumor activities. The purpose of this study was to investigate the anticancer effect of ISL on human oral squamous cell carcinoma (OSCC).
  
  
  
  The anti-OSCC effects of ISL were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, flow cytometry, reverse transcription-polymerase chain reaction, Western blotting, promoter activity, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, malignant phenotype analysis, microRNA, and xenografting.
  
  
  
  ISL induced OSCC cell cycle G2/M phase arrest, apoptosis, and DNA damage. However, the DNA repair-associated ataxia telangiectasia mutated (ATM) and phospho-ATM were downregulated, ATM mRNA remained unchanged, and the downstream signals were inhibited. ATM recovered when the caspase activity was blocked by Z-DVED-FMK. A low dose of ISL inhibited OSCC malignancy in vitro and reduced the tumor size in vivo.
  
  
  
  ATM was cleaved by ISL-activated caspase, thus inhibiting DNA repair in OSCC cells. Therefore, ISL is a promising chemopreventive agent against oral cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E360-E371, 2016.
authors.affiliation: School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shih-Min
authors.initials: SM
authors.lastname: Hsia
authors.affiliation: Institute of Oral Science, School of Dentistry, Chung Shan Medical University, Taichung, Taiwan.|Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Cheng-Chia
authors.initials: CC
authors.lastname: Yu
authors.affiliation: Institute of Oral Science, School of Dentistry, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Yin-Hua
authors.initials: YH
authors.lastname: Shih
authors.affiliation: Department of Oral and Maxillofacial Surgery, China Medical University Hospital, Taichung, Taiwan.|School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Michael
authors.initials: M
authors.lastname: Yuanchien Chen
authors.affiliation: Tissue Bank, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan.
authors.forename: Tong-Hong
authors.initials: TH
authors.lastname: Wang
authors.affiliation: Institute of Oral Science, School of Dentistry, Chung Shan Medical University, Taichung, Taiwan.|Department of Dental Hygiene, College of Health Care, China Medical University, Taichung, Taiwan.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Huang
authors.affiliation: Department of Dental Hygiene, College of Health Care, China Medical University, Taichung, Taiwan.
authors.forename: Tzong-Ming
authors.initials: TM
authors.lastname: Shieh
mesh_terms: D017209:Apoptosis; D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D002455:Cell Division; D045744:Cell Line, Tumor; D047188:Chalcones / Q000494:pharmacology*; D004249:DNA Damage; D006801:Humans; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000473:pathology*
chemical_list: D047188:Chalcones; C040920:isoliquiritigenin; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins
keywords: DNA damage; apoptosis; ataxia telangiectasia mutated (ATM); isoliquiritigenin; oral squamous cell carcinoma (OSCC)