The immunosuppressive agent tacrolimus induces p21WAF/CIP1WAF1/CIP1 via TGF-beta secretion.
Tacrolimus (Tac) is more immunosuppressive drug compared to cyclosporine (CsA). Our previous studies have demonstrated that CsA induces the expression of p21WAF/CIP1 expression. In this study we explored if like CsA, Tac also induces expression of p21WAF/CIP1. We also determined if induction of p21WAF/CIP1 by Tac is dependent on TGF-beta. Using RT-PCR and Western blot analysis, we studied the induction of p21WAF/CIP1 mRNA and protein in human T cells and A-549 cells (human lung adenocarcinoma cells) by Tac. The stimulation of p21WAF/CIP1 promoter activity was studied by luciferase assay using p21WAF/CIP1-luc, chimeric plasmid DNA containing a p21WAF/CIP1 promoter segment and luciferase reporter gene. Using anti-TGF-beta antibody, we studied if induction of p21WAF/CIP1 by tacrolimus is dependent on TGF-beta. The results demonstrate that Tac induced p21WAF/CIP1 mRNA and protein expression as well as stimulated its promoter activity in T cells and A-549 cells. The induction of p21WAF/CIP1 expression by tacrolimus was dependent on TGF-beta since a neutralizing anti-TGF-beta antibody inhibited induction of p21WAF/CIP1in A-549 cells. These data support the hypothesis that cyclin inhibitor p21WAF/CIP1 might represent a unified mediator of the anti-proliferative effects of Tac and other immunosuppressive agents. Strategies involving p21WAF/CIP1 induction should be considered a viable alternative strategy to achieve immunosuppression possibly with reduced toxicity associated with current immunosuppression.
Khanna
Ashwani K
AK
Medical College of Wisconsin, 8701, Watertown Plank Road, Milwaukee, WI 53226, USA. akkhanna@mcw.edu
D015153:Blotting, Western; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D017930:Genes, Reporter; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008156:Luciferases / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000187:drug effects; D016559:Tacrolimus / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D007166:Immunosuppressive Agents; D016212:Transforming Growth Factor beta; D008156:Luciferases; D016559:Tacrolimus