title: Cyclin-dependent kinase inhibitor p16 and p21 expression, and cell cycle change in human lens epithelial cell line SRA 01/04 following contact inhibition in normal culture.
abstract: OBJECTIVE
  To describe the pattern of expression of the cyclin-dependent kinase inhibitors (CDKIs) p16, p21 and p27, and the cell cycle in SRA 01/04 cells relative to contact inhibition.
  
  
  METHODS
  SRA 01/04 cells were grown to overconfluence under normal conditions. At various phases of the cell growth, cells were assayed by flow cytometry and Western blotting for the expression of CDKIs.
  
  
  RESULTS
  Expression of p16 was detected from early logarithmic growth to stationary phases, during which the number of cells in G(0)/G(1) increased from 46 to 69%. Expression of p21 was detected only during the overgrowth phase, when 60% of the cells were in G(0)/G(1). Expression of p27 was not observed in SRA 01/04 cells.
  
  
  CONCLUSIONS
  p16 expression was likely mediated by G(0)/G(1) arrest to induce contact inhibition in SRA 01/04. p21 expression may be related to withdrawal, and p27 deficiency may be related to the immortality of this cell line. It is possible for p16 to stop proliferation of lens epithelial cells like progressing posterior capsular opacification, by overexpression to mimic contact inhibition.
authors.affiliation: Division of Vision Research for Environmental Health, Medical Research Institute, Kanazawa Medical University, Uchinada, Japan. yamashir@kanazawa-med.ac.jp
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamashiro
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasaki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ibaraki
authors.forename: Kota
authors.initials: K
authors.lastname: Nagai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Hiromoto
authors.initials: H
authors.lastname: Yaguchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.forename: Hiromi
authors.initials: H
authors.lastname: Osada
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Sasaki
mesh_terms: D015153:Blotting, Western; D002452:Cell Count; D002453:Cell Cycle / Q000502:physiology*; D002460:Cell Line; D049109:Cell Proliferation; D003260:Contact Inhibition / Q000502:physiology*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27