title: The expression of p53-regulated genes in human cultured lymphoblastoid TSCE5 and WTK1 cell lines during spaceflight.
abstract: OBJECTIVE
  The space environment contains two major biologically significant influences; space radiations and microgravity. The 53 kDa tumour suppressor protein (p53) plays a role as a guardian of the genome through the activity of p53-centered signal transduction pathways. The aim of this study was to clarify the biological effects of space radiations, microgravity, and the space environment on the gene expression of p53-regulated genes.
  
  
  METHODS
  Space experiments were performed with two human cultured lymphoblastoid cell lines; one line (TSCE5) bears a wild-type p53 gene status, and another line (WTK1) bears a mutated p53 gene status. Under one gravity or microgravity conditions, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station for 8 days without experiencing stress during launching and landing because the cells were frozen during these periods. Ground control samples also were cultured for 8 days in the CBEF on the ground during the spaceflight. Gene expression was analysed using an Agilent Technologies 44 k whole human genome microarray DNA chip.
  
  
  RESULTS
  p53-dependent up-regulated gene expression was observed for 111, 95, and 328 genes and p53-dependent down-regulated gene expression was found for 177, 16, and 282 genes after exposure to space radiations, to microgravity, and to both, respectively.
  
  
  CONCLUSIONS
  The data provide the p53-dependent regulated genes by exposure to radiations and/or microgravity during spaceflight. Our expression data revealed genes that might help to advance the basic space radiation biology.
authors.affiliation: Department of Biology, School of Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Takahashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Katsunori
authors.initials: K
authors.lastname: Omori
authors.forename: Masaya
authors.initials: M
authors.lastname: Seki
authors.forename: Toko
authors.initials: T
authors.lastname: Hashizume
authors.forename: Toru
authors.initials: T
authors.lastname: Shimazu
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ishioka
authors.forename: Takeo
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D002460:Cell Line; D020869:Gene Expression Profiling; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D013026:Space Flight; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*; D014893:Weightlessness
chemical_list: D016159:Tumor Suppressor Protein p53