Expression of the c-myc and c-fos genes as a potential indicator of late radiation damage to the kidney.
OBJECTIVE
To evaluate proliferative response according to c-myc and c-fos gene expression as an early indicator of late radiation damage to the kidney.


METHODS
c-myc and c-fos gene expression was measured in the irradiated kidney of C3H/HeSlc mice using reverse transcriptase-polymerase chain reaction (RT-PCR) 24 h after 9, 12, and 15 Gy as well as 2 and 7 days after 15 Gy. In a second experiment, 12 Gy was administered to the right kidney plus the lower half of left kidney. The mice underwent left nephrectomy 24 h after, and the correlation between increased gene expression and elevation of the blood urea nitrogen (BUN) level representing late functional damage was investigated.


RESULTS
c-myc and c-fos expression increased in 1 of 10 controls and in 8 of 10 and 7 of 10 mice that received 15 Gy, respectively. Expression increased dose-dependently from 9 to 15 Gy. In mice having an increased BUN level, 7 of 10 and 8 of 10 were positive for c-myc and c-fos, respectively. All 6 mice having an unchanged BUN level were negative for c-fos, while 5 were negative for c-myc.


CONCLUSIONS
Measurement of c-myc and c-fos gene expression is potentially an early indicator of late radiation damage to the kidney.
Otsuka
M
M
Department of Radiology, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan. makoto@beppu.kyushu-u.ac.jp
Hatakenaka
M
M
Ishigami
K
K
Masuda
K
K
D000818:Animals; D001806:Blood Urea Nitrogen; D002455:Cell Division / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D005260:Female; D015870:Gene Expression; D016762:Genes, fos; D016259:Genes, myc; D007668:Kidney / Q000473:pathology / Q000528:radiation effects*; D007674:Kidney Diseases / Q000235:genetics* / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D012333:RNA, Messenger / Q000378:metabolism; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000235:genetics* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D012333:RNA, Messenger