Down-regulation of gadd153 by c-myc in rat fibroblasts and its effect on cell growth and radiation-induced apoptosis.
Using differential display reverse transcription PCR (DDRT - PCR), we found that a 360 bp cDNA fragment was absent in several c-myc transfected rat fibroblasts: REC:myc, REC:myc + ras and rat1-myc. These cells also showed enhanced sensitivity to gamma ray-induced apoptosis. This cDNA fragment was present in the parental REC (Rat Embryo Cells) and rat1 cells, and in c-Ha-ras transfected REC (REC:ras), all of which were relatively resistant to gamma ray-induced apoptosis. The cDNA fragment was subsequently cloned and used as a probe to screen a rat1 cDNA library, and identified as one of the growth arrest and DNA damaging-inducible genes, gadd153. In addition to the down-regulation of rat gadd153 in all the c-myc transfectants, methyl methanesulfonate (MMS)-induced transcription of the gadd153 was attenuated. The rat1-myc cells, when successfully transfected with and stably expressing the rat gadd153, showed a significantly longer doubling time compared to the parental cells. However, overexpression of gadd153 in rat1-myc cells did not affect gamma ray-induced apoptosis. Thus, the suppression of gadd153 appears to be inversely correlated with that of myc, but not involved in the myc-dependent apoptotic pathway.
Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York 10021, USA.
C
C
Chen
A
A
Nussenzweig
M
M
Guo
D
D
Kim
G C
GC
Li
C C
CC
Ling
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D022762:CCAAT-Enhancer-Binding Proteins; D002455:Cell Division / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D016259:Genes, myc; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D051742:Transcription Factor CHOP; D014157:Transcription Factors / Q000235:genetics*
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; C497251:Ddit3 protein, rat; D012333:RNA, Messenger; D014157:Transcription Factors; D051742:Transcription Factor CHOP