title: CD44(high) /ALDH1(high) head and neck squamous cell carcinoma cells exhibit mesenchymal characteristics and GSK3β-dependent cancer stem cell properties.
abstract: BACKGROUND
  CD44 and aldehyde dehydrogenase 1 (ALDH1) have been shown to be useful markers for identification of cancer stem cells (CSCs). We previously reported that glycogen synthase kinase 3β (GSK3β) is involved in regulation of the self-renewal ability of head and neck squamous cell carcinoma (HNSCC) CSCs. The purpose of the present study was to clarify the role of GSK3β in CD44(high) /ALDH1(high) HNSCC cells.
  
  
  METHODS
  Cells with greater expression of CD44 and higher ALDH1 enzymatic activity were FACS sorted from the OM-1 HNSCC cell line. The self-renewal ability of CD44(high) /ALDH1(high) cells was then examined using a tumor sphere formation assay. mRNA expressions of the stem cell markers Sox2, Oct4, and Nanog, as well as GSK3β were evaluated by real-time RT-PCR.
  
  
  RESULTS
  CD44(high) /ALDH1(high) cells exhibited higher tumor sphere forming ability and increased expression of stem cell markers as compared with CD44(high) /ALDH1(low) cells. Interestingly, spindle-shaped cells positive for vimentin were found in the CD44(high) /ALDH1(high) but not the CD44(high) /ALDH1(low) cell population. In addition, the ALDH1 activity and sphere forming ability of CD44(high) /ALDH1(high) cells was significantly inhibited by GSK3β knockdown. On the other hand, CD44(high) /ALDH1(low) cells exhibited high epidermal growth factor receptor (EGFR) expression and increased cell growth.
  
  
  CONCLUSIONS
  Our results show that GSK3β plays a major role in maintenance of stemness of CD44(high) /ALDH1(high) HNSCC cells. Additionally, they indicate a close relationship between CSC and mesenchymal characteristics in HNSCC.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Seino
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Shigeishi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Hashikata
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Higashikawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Tobiume
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Uetsuki
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Naruse
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Mohammad Zeshaan
authors.initials: MZ
authors.lastname: Rahman
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Ono
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Simasue
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Ohta
authors.affiliation: Department of Public Oral Health, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sugiyama
authors.affiliation: Department of Oral and Maxillofacial Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takechi
mesh_terms: D000080924:Aldehyde Dehydrogenase 1 Family; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000378:metabolism*; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000096:biosynthesis; D000071679:Glycogen Synthase Kinase 3 beta / Q000378:metabolism*; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis* / Q000187:drug effects; D007527:Isoenzymes / Q000096:biosynthesis / Q000187:drug effects* / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000201:enzymology / Q000378:metabolism; D000071317:Nanog Homeobox Protein / Q000096:biosynthesis; D014411:Neoplastic Stem Cells / Q000201:enzymology / Q000378:metabolism*; D050810:Octamer Transcription Factors / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000235:genetics; D050697:Retinal Dehydrogenase / Q000096:biosynthesis / Q000187:drug effects* / Q000378:metabolism; D055749:SOXB2 Transcription Factors / Q000096:biosynthesis; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D007527:Isoenzymes; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050810:Octamer Transcription Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D055749:SOXB2 Transcription Factors; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase; C512478:EGFR protein, human; D066246:ErbB Receptors; D000071679:Glycogen Synthase Kinase 3 beta
keywords: ALDH1; CD44; GSK3β; head and neck cancer; squamous cell carcinoma