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Suppressor of cytokine signalling-3 is up-regulated by androgen in prostate cancer cell lines and inhibits androgen-mediated proliferation and secretion.
- Source :
-
Endocrine-related cancer [Endocr Relat Cancer] 2007 Dec; Vol. 14 (4), pp. 1007-19. - Publication Year :
- 2007
-
Abstract
- Suppressors of cytokine signalling (SOCS) are induced by interleukins (ILs) and various peptide hormones and may prevent sustained activation of signalling pathways. We have previously shown that SOCS-3 antagonizes regulation of cellular events by cAMP and is expressed in human prostate cancer. To investigate possible effects of androgen on SOCS-3 protein expression, two prostate cancer cell lines (PC3-AR and LAPC4) were treated with different concentrations of R1881. Western blot analyses revealed induction of SOCS-3 protein expression in both cell lines by androgen, an effect which can be blocked by the anti-androgen bicalutamide. To further characterize the effects of R1881 on the SOCS-3 gene, promoter-reporter assay and real-time PCR were performed. We found no influence of androgen on promoter activity or SOCS-3 mRNA levels, thus suggesting a post-transcriptional effect of androgen. Concordant with our previous findings, we show a significant increase of SOCS-3 protein after androgen treatment in cells in which transcription was blocked, but not in those with impaired translation. In order to understand implications of SOCS-3 regulation by androgen, we used SOCS-3-negative LNCaP-IL-6 cells and stably transfected them with a tetracycline-responsive SOCS-3 Tet-On plasmid. We report that androgenic effects on cell proliferation and prostate-specific antigen secretion are significantly diminished following up-regulation of SOCS-3. In conclusion, androgen up-regulates SOCS-3 protein via post-transcriptional effects. SOCS-3 inhibits androgen-stimulated proliferation by influencing cell cycle regulation. Taken together with previous findings showing androgen receptor activation by IL-6, our results imply that androgen and cytokine signalling pathways interact at multiple levels in prostate cancer.
- Subjects :
- Cell Cycle
Cell Line
Humans
Male
Polymerase Chain Reaction
Prostate-Specific Antigen analysis
Prostatic Neoplasms genetics
Prostatic Neoplasms metabolism
Prostatic Neoplasms pathology
Suppressor of Cytokine Signaling 3 Protein
Suppressor of Cytokine Signaling Proteins genetics
Up-Regulation
Androgens pharmacology
Cell Division physiology
Suppressor of Cytokine Signaling Proteins physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1351-0088
- Volume :
- 14
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Endocrine-related cancer
- Publication Type :
- Academic Journal
- Accession number :
- 18045952
- Full Text :
- https://doi.org/10.1677/ERC-07-0172