Sequential alteration of proto-oncogene expression in liver, spleen, kidney and brain of mice subjected to whole body irradiation.
Reverse transcription polymerase chain reaction (RT-PCR) was performed to evaluate the sequential alteration of proto-oncogene mRNA expression in liver, spleen, kidney and brain of mice after whole body irradiation (WBI). The mRNAs investigated in this study were Fas, c-fos, c-myc. bcl-2, and p53, and glyceraldehyde-3-phosphate dehydrogenase mRNA was employed as internal control. C3H/He mice aged 9-10 weeks were exposed to WBI of 7 Gy using a cobalt-60 teletherapy unit, without anesthesia, and sacrificed before and 0.1, 0.5, 1, 2, 3, 6, 12, 24, 48 and 96 h after irradiation. Their liver, spleen, kidney and brain were taken and immediately stored in liquid nitrogen until ready for RT-PCR. Each specimen was homogenized to extract RNA for conventional RT-PCR. The liver of mice administered 7 Gy of WBI revealed no significant changes in the expression of each of the mRNAs examined. In the spleen, c-fos mRNA expression decreased at 2 h following irradiation, and increased remarkably thereafter. In the kidney, no significant change in the expression of each mRNA was shown. In the brain c-fos mRNA expression decreased 1-24 h after irradiation, and showed a recovery thereafter. The remarkable differences in the sequential changes of c-fos mRNA expression following irradiation between each organ revealed by the present experiment may be an important aid in determining the tissue-specific radiosensitivity to ionizing radiation. Further investigations are, however, needed to clarify the signal transduction mechanisms which are mediated by the expression of these proto-oncogenes in each tissue following irradiation.
Ogawa
Y
Y
Department of Radiology, Kochi Medical School, Japan.
Saibara
T
T
Terashima
M
M
Ono
M
M
Hamada
N
N
Nishioka
A
A
Inomata
T
T
Onishi
S
S
Yoshida
S
S
Seguchi
H
H
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects; D015870:Gene Expression / Q000528:radiation effects*; D016762:Genes, fos / Q000528:radiation effects; D007668:Kidney / Q000378:metabolism* / Q000528:radiation effects; D008099:Liver / Q000378:metabolism* / Q000528:radiation effects; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D011519:Proto-Oncogenes / Q000528:radiation effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013154:Spleen / Q000378:metabolism* / Q000528:radiation effects; D014158:Transcription, Genetic; D014916:Whole-Body Irradiation
D012333:RNA, Messenger