Cyclosporine inhibits growth through the activating transcription factor/cAMP-responsive element-binding protein binding site in the cyclin D1 promoter.
The immunosuppressive agent cyclosporine affects proliferation depending on the cellular system used. In an attempt to study the inhibitory effect of cyclosporine on proliferation of pancreatic acinar cells, we used AR42J cells as a model system. Here we demonstrate that cyclosporine inhibits growth of these cells by inducing G(1) cell cycle arrest. This effect is mediated by the 5' regulatory region of the cyclin D1 gene and leads to a reduction of cyclin D1 mRNA expression and protein abundance. We show that in AR42J cells the proximal cyclin D1 promoter contains a cis-regulated element, which is important for the maintenance of basal transcriptional activity. This element overlaps the described cAMP-responsive element (CRE) and confers cyclosporine sensitivity to the cyclin D1 promoter. Furthermore, the DNA binding activity of the CRE-binding protein (CREB) decreases through cyclosporine treatment and this is mediated by cyclosporine-induced reduction of CREB steady-state levels. These results demonstrate that cyclosporine can inhibit proliferation of acinar cells by targeting the cyclin D1 promoter at the proximal CRE via a reduction of CREB protein abundance.
Schneider
Gunter
G
Department of Internal Medicine I, University of Ulm, Germany.
Oswald
Franz
F
Wahl
Christian
C
Greten
Florian R
FR
Adler
Guido
G
Schmid
Roland M
RM
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002453:Cell Cycle; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D002469:Cell Separation; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D019938:Cyclin D1 / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D016572:Cyclosporine / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D015536:Down-Regulation; D005434:Flow Cytometry; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D016160:Retinoblastoma Protein / Q000096:biosynthesis; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
D017362:Cyclic AMP Response Element-Binding Protein; D007166:Immunosuppressive Agents; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D019938:Cyclin D1; D016572:Cyclosporine; D004247:DNA