Pap, Thomas and Nawrath, Michael and Heinrich, Jochen and Bosse, Magnus and Baier, Anja and Hummel, Klaus M. and Petrow, Peter and Kuchen, Stefan and Michel, Beat A. and Gay, Renate E. and Mueller-Ladner, Ulf and Moelling, Karin and Gay, Steffen (2004) Cooperation of ras- and c-MYC-dependent pathways in regulating the growth and invasiveness of synovial fibroblasts in rheumatoid arthritis. ARTHRITIS AND RHEUMATISM, 50 (9). pp. 2794-2802. ISSN 0004-3591, 1529-0131
Full text not available from this repository. (Request a copy)Abstract
Objective. To study the specific contribution of MAP kinase activator c-Raf-1 and one of its downstream transcription factors, c-Myc, to the growth and invasive behavior of rheumatoid arthritis synovial fibroblasts (RASFs). Methods. RASFs were transduced with retroviral constructs expressing dominant-negative mutants of c-Raf-1 or c-Myc (DN c-Raf-1 or DN c-Myc, respectively) or with the mock vector. The expression of wild-type and mutant proteins was confirmed by Western blotting. Growth curves of RASFs were recorded, and apoptosis was measured by flow cytometry. Invasiveness of RASFs was assessed in the SCID mouse model of RA. Immunohistochemistry was used to study the effects of DN c-Raf-1 on phosphorylated c-Jun and matrix metalloproteinase 1 (MMP-1) in RASFs implanted into SCID mice. The phosphorylation of ERK and JNK in DN c-Raf-1- and mock-transduced RASFs was determined in vitro by Western blotting. The levels of MMPs in these cells were measured by quantitative polymerase chain reaction (PCR). Results. Neither DN c-Raf-1 alone nor DN c-Myc alone significantly altered proliferation or apoptosis of RASFs, but both mutants together rapidly induced apoptosis. Inhibition of c-Raf-1 or c-Myc significantly reduced the invasiveness of RASFs in the SCID mouse model. DN c-Raf-1 decreased the phosphorylation of ERK and JNK in vitro and reduced the in vivo expression of phosphorylated c-Jun as well as the expression of disease-relevant MMPs. As determined by quantitative PCR, the inhibition was most pronounced for MMP-1 and MMP-3. Conclusion. The data demonstrate that Ras- and c-Myc-dependent signaling events cooperate to regulate the growth and invasiveness of RASFs. Targeting of both c-Raf-1 and c-Myc may constitute an interesting therapeutic approach in RA.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | N-TERMINAL KINASE; ACTIVATED PROTEIN-KINASES; TUMOR-SUPPRESSOR PTEN; NECROSIS-FACTOR-ALPHA; GENE-EXPRESSION; TRANSCRIPTION FACTOR; JUN PHOSPHORYLATION; JOINT DESTRUCTION; CELLS; APOPTOSIS; |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Pathologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 28 Jun 2021 12:54 |
| Last Modified: | 28 Jun 2021 12:54 |
| URI: | https://pred.uni-regensburg.de/id/eprint/37207 |
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