title: Establishment of a Three-dimensional Floating Cell Culture System for Screening Drugs Targeting KRAS-mediated Signaling Molecules.
abstract: OBJECTIVE
  Oncogenic mutations in the KRAS gene are critically involved in many human tumors but drugs targeting oncogenic KRAS have not yet been clinically developed. Herein, we established a three-dimensional floating (3DF) culture system for screening drugs that target KRAS-mediated signaling molecules.
  
  
  METHODS
  HKe3 cells, derived from colorectal cancer HCT116 cells and disrupted at mutated (mt) KRAS gene, were infected with a retrovirus expressing wild-type (wt) KRAS or mtKRAS to establish HKe3-derived cells expressing wtKRAS or mtKRAS. Established cells were cultured in 96-well plates with an ultra-low attachment surface and round bottom for 3DF culture.
  
  
  RESULTS
  HKe3-wtKRAS and HKe3-mtKRAS cells in 3DF culture rapidly assembled into respective single spherical structures (spheroids). Furthermore, mtKRAS but not wtKRAS expression inhibited luminal apoptosis in spheroids indicating that the 3DF culture was compatible with the 3D matrigel culture.
  
  
  CONCLUSIONS
  This 3DF culture system could be useful for screening drugs that target KRAS-mediated signaling molecules.
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsunoda
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Ishikura
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Doi
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Iwaihara
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Hidesima
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan.
authors.forename: Hao
authors.initials: H
authors.lastname: Luo
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Hirose
authors.affiliation: Department of Cell Biology, Faculty of Medicine Fukuoka University, Fukuoka, Japan Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka, Japan sshirasa@fukuoka-u.ac.jp.
authors.forename: Senji
authors.initials: S
authors.lastname: Shirasawa
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D006801:Humans; D058990:Molecular Targeted Therapy; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: 3-dimensional floating culture; KRAS; colorectal cancer; drug screening