title: MnSOD downregulation induced by extremely low 0.1 mGy single and fractionated X-rays and microgravity treatment in human neuroblastoma cell line, NB-1.
abstract: A human neuroblastoma cell line, NB-1, was treated with 24 h of microgravity simulation by clinostat, or irradiated with extremely small X-ray doses of 0.1 or 1.0 mGy using single and 10 times fractionation regimes with 1 and 2 h time-intervals. A quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) examination was performed for apoptosis related factors (BAX, CYTC, APAF1, VDAC1-3, CASP3, CASP8, CASP9 P53, AIF, ANT1 and 2, BCL2, MnSOD, autophagy related BECN and necrosis related CYP-40. The qRT-PCR results revealed that microgravity did not result in significant changes except for a upregulation of proapoptotic VDAC2, and downregulations of proapoptotic CASP9 and antiapoptotic MnSOD. After 0.1 mGy fractionation irradiation, there was increased expression of proapoptotic APAF1 and downregulation of proapoptotic CYTC, VDAC2, VDAC3, CASP8, AIF, ANT1, and ANT2, as well as an increase in expression of antiapoptotic BCL2. There was also a decrease in MnSOD expression with 0.1 mGy fractionation irradiation. These results suggest that microgravity and low-dose radiation may decrease apoptosis but may potentially increase oxidative stress.
authors.affiliation: Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
authors.forename: Hiroko P
authors.initials: HP
authors.lastname: Indo
authors.affiliation: Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Tomiyoshi
authors.affiliation: Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Suenaga
authors.affiliation: Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tomita
authors.affiliation: Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan ; Life Science Research Group, Department of Science and Applications, Japan Space Forum, 3-2-1 Surugadai, Chiyoda, Tokyo 100-0004, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan ; Utilization & Engineering Department, Japan Manned Space Systems Corporation, 2-1-6 Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Masuda
authors.affiliation: Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan ; Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035, USA.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Terada
authors.affiliation: Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan ; Department of Space Biology and Microgravity Sciences, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ishioka
authors.affiliation: Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan ; Department of Space Biology and Microgravity Sciences, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan ; Department of Invertebrates Zoology and Functional Morphology, Institute of Fundamental Medicine and Biology, Kazan Federal University 420008, Kremevskaya str., 17 Kazan 420-008, Russia ; Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
authors.forename: Oleg
authors.initials: O
authors.lastname: Gusev
authors.affiliation: Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
authors.forename: Richard
authors.initials: R
authors.lastname: Cornette
authors.affiliation: Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Okuda
authors.affiliation: Center for Applied Space Medicine and Human Research, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Mukai
authors.affiliation: Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan ; Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Hideyuki J
authors.initials: HJ
authors.lastname: Majima
keywords: NB-1; extremely small dose; microgravity; neuron; space radiation