Dexamethasone-induced gene 2 (dig2) is a novel pro-survival stress gene induced rapidly by diverse apoptotic signals.
Glucocorticoid hormones induce apoptosis in lymphoid cells. This process requires de novo RNA/protein synthesis. Here we report the identification and cloning of a novel dexamethasone-induced gene designated dig2. Using Affymetrix oligonucleotide microarray analysis of approximately 10,000 genes and expressed sequence tags, we found that the expression of dig2 mRNA is significantly induced not only in the murine T cell lymphoma lines S49.A2 and WEHI7.2 but also in normal mouse thymocytes following dexamethasone treatment. This result was confirmed by Northern blot analysis. The induction of dig2 mRNA by dexamethasone appears to be mediated through the glucocorticoid receptor as it is blocked in the presence of RU486, a glucocorticoid receptor antagonist. Furthermore, we demonstrated that dig2 is a novel stress response gene, as its mRNA is induced in response to a variety of cellular stressors including thapsigargin, tunicamycin, and heat shock. In addition, the levels of dig2 mRNA were up-regulated after treatment with the apoptosis-inducing chemotherapeutic drug etoposide. Though the function of dig2 is unknown, dig2 appears to have a pro-survival function, as overexpression of dig2 reduces the sensitivity of WEHI7.2 cells to dexamethasone-induced apoptosis.
Department of Medicine, Comprehensive Cancer Center, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Cleveland, Ohio 44106, USA.
Zhengqi
Z
Wang
Michael H
MH
Malone
Michael J
MJ
Thomenius
Fei
F
Zhong
Fang
F
Xu
Clark W
CW
Distelhorst
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D001483:Base Sequence; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D003907:Dexamethasone / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D020224:Expressed Sequence Tags; D005260:Female; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014407:Tumor Cells, Cultured
D048868:Adaptor Proteins, Signal Transducing; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C450979:Ddit4l protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors; D005047:Etoposide; D003907:Dexamethasone