Identification of ALDH4 as a p53-inducible gene and its protective role in cellular stresses.
To identify additional targets of p53, we used a cDNA microarray system to examine gene-expression patterns in response to enforced expression of exogenous p53 in p53-deficient cancer cells, and identified the aldehyde dehydrogenase 4 ( ALDH4) gene as a direct target of p53. ALDH4 is a mitochondrial-matrix NAD+-dependent enzyme catalyzing the second step of the proline degradation pathway. Expression of ALDH4 mRNA was induced in HCT116 cells in response to DNA damage caused by adriamycin treatment, in a p53-dependent manner. ALDH4 contains a potential p53 binding sequence in intron1 and the interaction of p53 with the site was shown by EMSA and ChIP assays. We confirmed p53-dependent transcriptional activity of the binding site by means of a reporter assay. Inhibition of ALDH4 expression by antisense oligonucleotides was able to enhance cell death induced by infection with Ad-p53. H1299 cells transformed to over-express ALDH4 showed significantly lower intracellular reactive oxygen species (ROS) levels than parental or control cells after treatment with hydrogen peroxide or UV. Those cells were also resistant to cell damage caused by hydrogen peroxide. These results suggest that p53 might play a protective role against cell damage induced by generation of intracellular ROS, through transcriptional activation of ALDH4.
Human Genome Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Kyong-Ah
KA
Yoon
Human Genome Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Yusuke
Y
Nakamura
Human Genome Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. harakawa@gan2.res.ncc.go.jp.|Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. harakawa@gan2.res.ncc.go.jp.
Hirofumi
H
Arakawa
D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; D000444:Aldehyde Dehydrogenase / Q000235:genetics* / Q000502:physiology*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis; D001665:Binding Sites; D015152:Blotting, Northern; D002453:Cell Cycle; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival; D002843:Chromatin / Q000378:metabolism; D004249:DNA Damage; D018076:DNA, Complementary / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology; D005434:Flow Cytometry; D017930:Genes, Reporter; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological; D013997:Time Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014466:Ultraviolet Rays
D000903:Antibiotics, Antineoplastic; D002843:Chromatin; D018076:DNA, Complementary; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D006861:Hydrogen Peroxide; D008156:Luciferases; D000444:Aldehyde Dehydrogenase; D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; C494240:ALDH4A1 protein, human