title: Gene expression profiles of prostate cancer stem cells isolated by aldehyde dehydrogenase activity assay.
abstract: OBJECTIVE
  Prostate cancer cells include a small population of cancer stem-like/cancer initiating cells, which have roles in cancer initiation and progression. Recently aldehyde dehydrogenase activity was used to isolate stem cells of various cancer and normal cells. We evaluated the aldehyde dehydrogenase activity of the human prostate cancer cell line 22Rv1 (ATCC®) with the ALDEFLUOR® assay and determined its potency as prostate cancer stem-like/cancer initiating cells.
  
  
  METHODS
  The human prostate cancer cell line 22Rv1 was labeled with ALDEFLUOR reagent and analyzed by flow cytometry. ALDH1(high) and ALDH1(low) cells were isolated and tumorigenicity was evaluated by xenograft transplantation into NOD/SCID mice. Tumor sphere forming ability was evaluated by culturing in a floating condition. Invasion capability was evaluated by the Matrigel™ invasion assay. Gene expression profiling was assessed by microarrays and reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  ALDH1(high) cells were detected in 6.8% of 22Rv1 cells, which showed significantly higher tumorigenicity than ALDH1(low) cells in NOD/SCID mice (p < 0.05). Gene expression profiling revealed higher expression of the stem cell related genes PROM1 and NKX3-1 in ALDH1(high) cells than in ALDH1(low) cells. ALDH1(high) cells also showed higher invasive capability and sphere forming capability than ALDH1(low) cells.
  
  
  CONCLUSIONS
  Results indicate that cancer stem-like/cancer initiating cells are enriched in the ALDH1(high) population of the prostate cancer cell line 22Rv1. This approach may provide a breakthrough to further clarify prostate cancer stem-like/cancer initiating cells. To our knowledge this is the first report of cancer stem-like/cancer initiating cells of 22Rv1 using the aldehyde dehydrogenase activity assay.
authors.affiliation: Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Nishida
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hirohashi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Torigoe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Akari
authors.initials: A
authors.lastname: Takahashi
authors.forename: Naoya
authors.initials: N
authors.lastname: Masumori
authors.forename: Taiji
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sato
mesh_terms: D000080924:Aldehyde Dehydrogenase 1 Family; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009374:Neoplasms, Experimental; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D011467:Prostate / Q000201:enzymology* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D012334:RNA, Neoplasm / Q000235:genetics*; D050697:Retinal Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D012334:RNA, Neoplasm; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; C515028:ALDH1A1 protein, mouse; D050697:Retinal Dehydrogenase