title: Quercetin in elimination of tumor initiating stem-like and mesenchymal transformation property in head and neck cancer.
abstract: BACKGROUND
  Previously, we enriched a subpopulation of head and neck cancer-derived tumor initiating cells (HNC-TICs) presented high tumorigenic, chemo-radioresistant, and coupled with epithelial-mesenchymal transition (EMT) properties. The purpose of this study was to investigate the therapeutic effect and molecular mechanisms of quercetin on HNC-TICs.
  
  
  METHODS
  ALDH1 activity of head and neck cancer cells with quercetin treatment was assessed by the Aldefluor assay flow cytometry analysis. Self-renewal, invasiveness, and EMT capability of HNC-TICs with different doses of quercetin was presented.
  
  
  RESULTS
  We first observed that the treatment of quercetin significantly downregulated the ALDH1 activity of head and neck cancer cells in a dose-dependent manner (p < .05). Moreover, quercetin reduced self-renewal property and stemness signatures expression in head and neck cancer-derived sphere cells. The migration ability of head and neck cancer-derived sphere cells was lessened under quercetin treatment partially due to the decreased productions of Twist, N-cadherin, and vimentin.
  
  
  CONCLUSIONS
  Quercetin suppressing HNC-TICs characteristics may therefore be valuable therapeutics clinically in combination with standard treatment modalities.
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Chang
authors.forename: Fang-Wei
authors.initials: FW
authors.lastname: Hu
authors.forename: Cheng-Chia
authors.initials: CC
authors.lastname: Yu
authors.forename: Hsiu-Huan
authors.initials: HH
authors.lastname: Wang
authors.forename: Hsiang-Pu
authors.initials: HP
authors.lastname: Feng
authors.forename: Chih
authors.initials: C
authors.lastname: Lan
authors.forename: Lo-Lin
authors.initials: LL
authors.lastname: Tsai
authors.forename: Yu-Chao
authors.initials: YC
authors.lastname: Chang
mesh_terms: D000080924:Aldehyde Dehydrogenase 1 Family; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000188:drug therapy*; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D014411:Neoplastic Stem Cells / Q000187:drug effects*; D011794:Quercetin / Q000627:therapeutic use*; D050697:Retinal Dehydrogenase / Q000037:antagonists & inhibitors
chemical_list: D007527:Isoenzymes; D011794:Quercetin; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase