Expression of p53-Regulated Genes in Cultured Mammalian Cells After Exposure to A Space Environment

Abstract

The space environment contains two major biologically significant influences; space radiation and microgravity. The tumor suppressor gene product p53 is generally thought to contribute to the genetic stability of cells with DNA damage through the activity of p53 initiated signal transduction pathways. We propose to investigate the expression of p53-regulated g e n e s i n c u l t u r e d m a m m a l i a n c e l l s a f t e r exposure to a space environment. We expect that the data from this proposal will be useful for designing physiological protection against the serious effects of space radiation during long-term stays in space. ©2009 Jpn. Soc. Biol. Sci.

The First Life Science Experiments in ISS: Reports of "Rad Gene"-Space Radiation Effects on Human Cultured Cells-

“…Ten ml of suspension cells were placed into a bag (ca 4 cm × 7 cm) which was constructed from a sheet of polypropylene (Hybrid MekkinBag HM-1304, HOGY, Osaka, Japan) (Ohnishi et al, 2009a), and the samples were then frozen at −80˚C (Fig. 3a).…”

“…1) (Ohnishi et al, 2009a). From a view of safety long term stay in space, biological effects of space radiations have been studied many times in these about 10 years by space shuttles.…”

“…2). When living organisms such as cells, organs and whole bodies were exposed to radiation environments with low dose or low dose-rates, they acquired a radioadaptive response which was manifested as a depression of cell killing, gene mutations, micronuclei, chromosome aberrations, and malignant transformation (Takahashi and Ohnishi, 2009a). Particular interest in the radioadaptive response is the dose window which is a specific range of doses and/or dose rates which can serve as pre-irradiation exposures prior to challenging radiation (Yonezawa et al, 1990(Yonezawa et al, , 1996Takahashi and Ohnishi, 2009a).…”

“…When living organisms such as cells, organs and whole bodies were exposed to radiation environments with low dose or low dose-rates, they acquired a radioadaptive response which was manifested as a depression of cell killing, gene mutations, micronuclei, chromosome aberrations, and malignant transformation (Takahashi and Ohnishi, 2009a). Particular interest in the radioadaptive response is the dose window which is a specific range of doses and/or dose rates which can serve as pre-irradiation exposures prior to challenging radiation (Yonezawa et al, 1990(Yonezawa et al, , 1996Takahashi and Ohnishi, 2009a). It has been reported that a pre-irradiation with low-dose and low dose-rates can induce a tumor suppressor gene, p53-dependent radio-adaptive response in mammalian cells (Sasaki, 1995;Takahashi, 2001;Takahashi et al, 2001Takahashi et al, , 2008bMatsumoto et al, 2007;Takahashi and Ohnishi, 2009b).…”

Expression of p53-regulated genes in human cultured lymphoblastoid TSCE5 and WTK1 cell lines after spaceflight in a frozen state

“…p53 contributes to the genetic stability of cells by protecting them from DNA damage through p53-centered signal transduction pathways (Lane, 1992). "Rad Gene" project was accepted by Japan Aerospace Exploration Agency (JAXA) in 2000 (Ohnishi et al, 2009b). This project was designed to investigate gene expression in p53-regulated genes, and to determine if they are induced or depressed in cultured mammalian cells after exposure to space radiation during spaceflight in a frozen state.…”