Back to Search
Start Over
In vivo real-time imaging of TGF-beta-induced transcriptional activation of the RANK ligand gene promoter in intraosseous prostate cancer
- Source :
- The Prostate. 59(4)
- Publication Year :
- 2004
-
Abstract
- BACKGROUND Current animal models of prostate cancer (CaP) bone metastasis do not allow measurement of either tumor growth in bone over time or activation of gene promoters in intraosseous tumors. To develop these methods, we used bioluminescent imaging (BLI) to determine if expression of receptor activator of NF-κB ligand (RANKL), a pro-osteoclastogenic factor that promotes CaP bone metastases, is modulated by the bone matrix protein transforming growth factor-β (TGF-β) in vivo. METHODS C4-2B human CaP cells were treated with TGF-β in vitro and RANKL mRNA and protein production were measured by polymerase chain reaction (PCR) and ELISA, respectively. Then C4-2B cells stably transfected with the RANKL promoter driving luciferase (lux) were injected intra-tibially into severe combined immundeficient (SCID) mice. Tumors were subjected to BLI every 2 weeks for 6 weeks and serum prostate specific antigen (PSA) was measured using ELISA. Vehicle (V), 1,25 dihydroxyvitamin D (VitD), or TGF-β was administered to mice with established tumors and BLI to measure RANKL promoter activity was performed. Tumors were then subjected to immunohistochemistry for lux and assayed for RANKL mRNA levels. RESULTS TGF-β induced RANKL protein and mRNA expression and activated the RANKL promoter activity in a dose-dependent manner in vitro. BLI demonstrated an increase in intraosseous tumor size over time, which correlated with serum PSA levels. Administration of TGF-β and VitD to mice with established intraosseous tumors increased lux activity compared to V. Intratibial tumor RANKL mRNA expression paralleled the increased promoter activity. Immunohistochemistry confirmed the presence of lux in the intraosseous tumors. CONCLUSIONS These results demonstrate the ability to measure intraosseous tumor growth over time and gene promoter activation in an established intraosseous tumor in vivo and also demonstrate that TGF-β induces activates the RANKL promoter. These results provide a novel method to explore the biology of CaP bone metastases. © 2004 Wiley-Liss, Inc.
- Subjects :
- Male
Transcriptional Activation
Urology
Bone Neoplasms
Enzyme-Linked Immunosorbent Assay
Mice, SCID
Transfection
Polymerase Chain Reaction
Metastasis
Mice
In vivo
Transforming Growth Factor beta
medicine
Animals
RNA, Messenger
Promoter Regions, Genetic
Membrane Glycoproteins
biology
Receptor Activator of Nuclear Factor-kappa B
Activator (genetics)
business.industry
RANK Ligand
Bone metastasis
Prostatic Neoplasms
Promoter
Neoplasms, Experimental
Prostate-Specific Antigen
medicine.disease
Oncology
RANKL
Luminescent Measurements
biology.protein
Cancer research
Immunohistochemistry
business
Carrier Proteins
Transforming growth factor
Subjects
Details
- ISSN :
- 02704137
- Volume :
- 59
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- The Prostate
- Accession number :
- edsair.doi.dedup.....564546305265338404cac7eb2133f536