ICER-IIgamma is a tumor suppressor that mediates the antiproliferative activity of cAMP.
The second messenger cAMP inhibits the proliferation of most cell types. The nuclear response of cAMP is mediated by transcription factors like the cAMP-Responsive Element Modulator (CREM) gene. One of the products of the CREM gene, the transcriptional repressor Inducible cAMP Early Repressor-IIgamma (ICER-IIgamma), is induced by cAMP. ICER-IIgamma blocks cells at the G2/M boundary of the cell cycle. Here we show that ICER-IIgamma dramatically inhibits the growth and DNA synthesis of mouse pituitary tumor cells and human choriocarcinoma cells. This alteration in cell growth is coupled with reduced ability of these cells to grow in an anchorage-independent manner and to form tumors in mice. These data demonstrate that ICER-IIgamma is a tumor suppressor gene product mediating the antiproliferative activity of cAMP.
Razavi
R
R
Department of Obstetrics and Gynecology, New Jersey Medical School, Newark 07103, USA.
Ramos
J C
JC
Yehia
G
G
Schlotter
F
F
Molina
C A
CA
D000362:Agar; D000818:Animals; D002455:Cell Division; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism*; D051786:Cyclic AMP Response Element Modulator; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D006801:Humans; D051379:Mice; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D012097:Repressor Proteins; D014407:Tumor Cells, Cultured
D003470:Culture Media; D004268:DNA-Binding Proteins; D016760:Proto-Oncogene Proteins c-fos; D012097:Repressor Proteins; D051786:Cyclic AMP Response Element Modulator; D000362:Agar; D000242:Cyclic AMP