1
|
Zhang X, Jiang P, Wang C. The role of prostate-specific antigen in the osteoblastic bone metastasis of prostate cancer: a literature review. Front Oncol 2023; 13:1127637. [PMID: 37746292 PMCID: PMC10513387 DOI: 10.3389/fonc.2023.1127637] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 08/23/2023] [Indexed: 09/26/2023] Open
Abstract
Prostate cancer is the only human malignancy that generates predominantly osteoblastic bone metastases, and osteoblastic bone metastases account for more than 90% of osseous metastases of prostate cancer. Prostate-specific antigen (PSA) plays an important role in the osteoblastic bone metastasis of prostate cancer, which can promote osteomimicry of prostate cancer cells, suppress osteoclast differentiation, and facilitate osteoblast proliferation and activation at metastatic sites. In the meantime, it can activate osteogenic factors, including insulin-like growth factor, transforming growth factor β2 and urokinase-type plasminogen activator, and meanwhile suppress osteolytic factors such as parathyroid hormone-related protein. To recapitulate, PSA plays a significant role in the osteoblastic predominance of prostate cancer bone metastasis and bone remodeling by regulating multiple cells and factors involved in osseous metastasis.
Collapse
Affiliation(s)
| | | | - Chaojun Wang
- Department of Urology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| |
Collapse
|
2
|
Ardura JA, Gutiérrez-Rojas I, Álvarez-Carrión L, Rodríguez-Ramos MR, Pozuelo JM, Alonso V. The secreted matrix protein mindin increases prostate tumor progression and tumor-bone crosstalk via ERK 1/2 regulation. Carcinogenesis 2020; 40:828-839. [PMID: 31168562 DOI: 10.1093/carcin/bgz105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 05/03/2019] [Accepted: 06/04/2019] [Indexed: 12/15/2022] Open
Abstract
Advanced prostate cancer cells preferentially metastasize to bone by acquiring a bone phenotype that allows metastatic cells to thrive in the skeletal environment. Identification of factors that promote the expression of ectopic bone genes-process known as osteomimicry-leading to tumor progression is crucial to prevent and treat metastatic prostate cancer and prolong life expectancy for patients. Here, we identify the extracelular matrix protein mindin in the secretome of prostate adenocarcinoma cells and show that mindin overexpression in human and mouse TRAMP-C1-induced prostate tumors correlates with upregulated levels of bone-related genes in the tumorigenic prostate tissues. Moreover, mindin silencing decreased osteomimicry in adenocarcinoma cells and in the prostate tumor mice model, as well as reduced tumor cell proliferation, migration and adhesion to bone cells. Inhibition of the extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation decreased the proliferative, migratory and pro-adhesion actions of mindin on prostate tumor cells. In addition, conditioned media obtained by crosstalk stimulation of either osteocytes or osteoblasts with the secretome of TRAMP-C1 cells promoted osteomimicry in prostate tumor cells; an effect inhibited by mindin silencing of TRAMP-C1 cells. In vivo, tibiae of primary tumor-bearing mice overexpressed the pro-angiogenic and pro-metastattic factor vascular endothelial growth factor receptor 2 (VEGFR2) in a mindin-dependent manner. Our findings indicate that mindin is a novel regulator of osteomimicry in prostate tumors and potentially mediates tumor-bone cell crosstalk, suggesting its promising role as a target to inhibit bone metastases.
Collapse
Affiliation(s)
- Juan A Ardura
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | | | | | - M Rosario Rodríguez-Ramos
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | - José M Pozuelo
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| | - Verónica Alonso
- Bone Physiopathology laboratory, Applied Molecular Medicine Institute (IMMA).,Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Campus Monteprincipe, Alcorcón, Madrid, Spain
| |
Collapse
|
3
|
Hai L, Szwarc MM, Lonard DM, Rajapakshe K, Perera D, Coarfa C, Ittmann M, Fernandez-Valdivia R, Lydon JP. Short-term RANKL exposure initiates a neoplastic transcriptional program in the basal epithelium of the murine salivary gland. Cytokine 2019; 123:154745. [PMID: 31226438 DOI: 10.1016/j.cyto.2019.154745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022]
Abstract
Although salivary gland cancers comprise only ∼3-6% of head and neck cancers, treatment options for patients with advanced-stage disease are limited. Because of their rarity, salivary gland malignancies are understudied compared to other exocrine tissue cancers. The comparative lack of progress in this cancer field is particularly evident when it comes to our incomplete understanding of the key molecular signals that are causal for the development and/or progression of salivary gland cancers. Using a novel conditional transgenic mouse (K5:RANKL), we demonstrate that Receptor Activator of NFkB Ligand (RANKL) targeted to cytokeratin 5-positive basal epithelial cells of the salivary gland causes aggressive tumorigenesis within a short period of RANKL exposure. Genome-wide transcriptomic analysis reveals that RANKL markedly increases the expression levels of numerous gene families involved in cellular proliferation, migration, and intra- and extra-tumoral communication. Importantly, cross-species comparison of the K5:RANKL transcriptomic dataset with The Cancer Genome Atlas cancer signatures reveals the strongest molecular similarity with cancer subtypes of the human head and neck squamous cell carcinoma. These studies not only provide a much needed transcriptomic resource to mine for novel molecular targets for therapy and/or diagnosis but validates the K5:RANKL transgenic as a preclinical model to further investigate the in vivo oncogenic role of RANKL signaling in salivary gland tumorigenesis.
Collapse
Affiliation(s)
- Lan Hai
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Reproductive Medicine Center of Henan Provincial People's Hospital, Zhengzhou, Henan Province, PR China
| | - Maria M Szwarc
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - David M Lonard
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Kimal Rajapakshe
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Dimuthu Perera
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Michael Ittmann
- Department of Pathology, Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | | | - John P Lydon
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
4
|
González Á, García de Durango C, Alonso V, Bravo B, Rodríguez de Gortázar A, Wells A, Forteza J, Vidal-Vanaclocha F. Distinct Osteomimetic Response of Androgen-Dependent and Independent Human Prostate Cancer Cells to Mechanical Action of Fluid Flow: Prometastatic Implications. Prostate 2017; 77:321-333. [PMID: 27813116 DOI: 10.1002/pros.23270] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 10/11/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND METHODS Prostate cancer frequently expresses an osteomimetic phenotype, but it is unclear how it is regulated and what biological and clinical implications it confers. Because mechanical forces physiologically regulate bone-remodeling activity in osteocytes, we hypothesized that mechanical action of fluid flow (MAFF) at the cancer microenvironment may similarly foster prostate cancer cell osteomimicry. RESULTS We showed that in vitro MAFF on androgen-dependent (LNCap) and androgen-independent (PC3) prostate cancer cells remarkably increased OPG, VEGF, RunX2, PTH1R, and PTHrP gene expression in both cell lines irrespective of their androgen dependency. MAFF also altered the cytokine secretion pattern of prostate cancer cells, including Ang2, SCF, and TNFα increase with TRAIL decrease in the supernatant of both cell lines; preferential increase of Leptin and PDGF-BB in LnCap and of VEGF, IL-8, and G-CSF in PC3; and exclusive increase of FGFβ, MIF, and PECAM-1 with HGF decrease in LnCap, and of TGBβ1, HGF, M-CSF, CXCL1, and CCL7 with NGF decrease in PC3. Murine MLO-Y4 osteocyte-conditioned medium (CM) abrogated M-CSF, G-CSG, IL-8, TNFα, and FGFβ secretion-stimulating activity of mechanical stimulation on PC3 cells, and did the opposite effect on LnCap cells. However, MAFF fostered osteomimetic gene expression response of PC3 cells, but not of LnCap cells, to mechanically stimulated osteocyte-CM. Moreover, it abrogated TNFα and IL-8 secretion inhibitory effect of osteocyte-CM on mechanically stimulated PC3 cells and G-CSF, TNFα, and FGFβ-stimulating effect on mechanically stimulated LnCap cells. CONCLUSIONS MAFF activated osteoblast-like phenotype of prostate cancer cells and altered their responses to osteocyte soluble factors. It also induced osteocyte production of osteomimetic gene expression- and cytokine secretion-stimulating factors for prostate cancer cells, particularly, when they were mechanically stimulated. Importantly, MAFF induced a prometastatic response in androgen-independent prostate cancer cells, suggesting the interest of mechanical stimulation-dependent transcription and secretion patterns as diagnostic biomarkers, and as therapeutic targets for the screening of bone-metastasizing phenotype inhibitors upregulated during prostate cancer cell response to MAFF at the cancer microenvironment. Prostate 77:321-333, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Álvaro González
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Cira García de Durango
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Madrid, Spain
| | - Verónica Alonso
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Madrid, Spain
| | - Beatriz Bravo
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Madrid, Spain
| | | | - Alan Wells
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jerónimo Forteza
- Valencia Institute of Pathology, Catholic University of Valencia School of Medicine and Odontology, Valencia, Spain
| | - Fernando Vidal-Vanaclocha
- Valencia Institute of Pathology, Catholic University of Valencia School of Medicine and Odontology, Valencia, Spain
| |
Collapse
|
5
|
De Castro J, García R, Garrido P, Isla D, Massuti B, Blanca B, Vázquez J. Therapeutic Potential of Denosumab in Patients With Lung Cancer: Beyond Prevention of Skeletal Complications. Clin Lung Cancer 2015; 16:431-46. [PMID: 26264596 DOI: 10.1016/j.cllc.2015.06.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 06/09/2015] [Accepted: 06/16/2015] [Indexed: 12/29/2022]
Abstract
Approximately up to 40% of patients with lung cancer develop bone metastasis, with 22% to 59% of them experiencing skeletal-related events (SREs), which result in an important quality of life deterioration and economic burden. Denosumab, a fully human antibody that targets the receptor activator of nuclear factor-κB (RANK) ligand (RANKL), is indicated for prevention of SREs in patients with solid tumors and has demonstrated superiority in breast and prostate cancer, and in other solid tumors, in reducing the risk of first SRE by 17% versus zoledronic acid. In the subset of patients with non-small-cell lung carcinoma (NSCLC), denosumab has also shown a positive trend to SRE risk reduction. Denosumab might have direct or indirect antitumor effects. Cancer cells produce factors that stimulate increased bone resorption by osteoclasts, which in turn release tumor growth factors into the bone microenvironment, initiating a tumor/bone vicious cycle. An increasing body of evidence suggests RANK/RANKL signaling plays a role in this tumorigenesis. Both proteins are overexpressed in different tumor types including lung cancer cells. RANK/RANKL signaling activates nuclear factor-κB pathways related to lung carcinogenesis and increases intercellular adhesion molecule 1 expression and MEK/extracellular signal-regulated kinase phosphorylation, which in turn enhances tumor cell migration. In animal NSCLC models, denosumab delayed bone metastases and reduced skeletal tumor growth. In patients with lung cancer (post hoc analysis), denosumab prolonged overall survival by 1.2 months versus zoledronic acid (P = .01). This hypothesis-generating outcome warrants further investigation and 2 studies in lung cancer are ongoing to elucidate the therapeutic potential of denosumab beyond SRE prevention.
Collapse
Affiliation(s)
| | - Rosario García
- Complexo Hospitalario Universitario de A Coruña, A Coruña, Spain
| | | | - Dolores Isla
- Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
| | | | | | | |
Collapse
|
6
|
Abstract
This review focuses on the pathologic entities associated with hyperparathyroidism in humans. A discussion of the lesions, their embryology, and pathologic features is included. Immunohistology, cytopathology, and a brief overview of molecular aspects of the lesion are included.
Collapse
Affiliation(s)
- Virginia A LiVolsi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
| | - Kathleen T Montone
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Zubair N Baloch
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA
| |
Collapse
|
7
|
P21-activated kinase 5 plays essential roles in the proliferation and tumorigenicity of human hepatocellular carcinoma. Acta Pharmacol Sin 2014; 35:82-8. [PMID: 23685956 DOI: 10.1038/aps.2013.31] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 03/08/2013] [Indexed: 12/15/2022] Open
Abstract
AIM To investigate the roles of P21-activated kinase 5 (PAK5) in proliferation and tumorigenicity of human hepatocellular carcinoma (HCC). METHODS HCC and matched paraneoplastictis tissue samples were obtained from 30 patients. Human HCC cell lines SMMC7721, HepG2, Hep3B, SK-HEP-1, Huh-7, and liver cell line HL-7702 were examined. The expression of PAK5 gene was studied using real-time qPCR and Western blotting. Cell proliferation was quantified with the MTT assay. Cell cycle was analyzed with flow cytometry. The tumorigenicity of Lv-shRNA-transfected HepG2 cells was evaluated in BALB/cA nude mice. RESULTS The mRNA level of PAK5 was significantly higher in 25 out of 30 HCC samples compared to the matched paraneoplastic tissues. The HCC cell lines showed varying expression of PAK5 protein, and the highest level was found in the HepG2 cells. PAK5 gene silencing in HepG2 cells markedly reduced the cell proliferation and colony formation, and induced cell cycle arrest in the G1 phase. Furthermore, PAK5 gene silencing suppressed the tumor formation in nude mice, and significantly decreased the expression of HCC-related genes Cyclin D1 and beta-catenin. CONCLUSION PAK5 may play essential roles in the initiation and progression of human HCC. Thus, it may be an effective therapeutic target or perhaps serve as a clinical diagnostic or prognostic marker in human HCC.
Collapse
|
8
|
Zhang H, Yu C, Dai J, Keller JM, Hua A, Sottnik JL, Shelley G, Hall CL, Park SI, Yao Z, Zhang J, McCauley LK, Keller ET. Parathyroid hormone-related protein inhibits DKK1 expression through c-Jun-mediated inhibition of β-catenin activation of the DKK1 promoter in prostate cancer. Oncogene 2013; 33:2464-77. [PMID: 23752183 DOI: 10.1038/onc.2013.203] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 03/26/2013] [Accepted: 04/19/2013] [Indexed: 12/17/2022]
Abstract
Prostate cancer (PCa)bone metastases are unique in that majority of them induce excessive mineralized bone matrix, through undefined mechanisms, as opposed to most other cancers that induce bone resorption. Parathyroid hormone-related protein (PTHrP) is produced by PCa cells and intermittent PTHrP exposure has bone anabolic effects, suggesting that PTHrP could contribute to the excess bone mineralization. Wnts are bone-productive factors produced by PCa cells, and the Wnt inhibitor Dickkopfs-1 (DKK1) has been shown to promote PCa progression. These findings, in conjunction with the observation that PTHrP expression increases and DKK1 expression decreases as PCa progresses, led to the hypothesis that PTHrP could be a negative regulator of DKK1 expression in PCa cells and, hence, allow the osteoblastic activity of Wnts to be realized. To test this, we first demonstrated that PTHrP downregulated DKK1 mRNA and protein expression. We then found through multiple mutated DKK1 promoter assays that PTHrP, through c-Jun activation, downregulated the DKK1 promoter through a transcription factor (TCF) response element site. Furthermore, chromatin immunoprecipitation (ChIP) and re-ChIP assays revealed that PTHrP mediated this effect through inducing c-Jun to bind to a transcriptional activator complex consisting of β-catenin, which binds the most proximal DKK1 promoter, the TCF response element. Together, these results demonstrate a novel signaling linkage between PTHrP and Wnt signaling pathways that results in downregulation of a Wnt inhibitor allowing for Wnt activity that could contribute the osteoblastic nature of PCa.
Collapse
Affiliation(s)
- H Zhang
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - C Yu
- 1] Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA [2] Department of Immunology, Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Educational Ministry, Tianjin Medical University, Tianjin, China
| | - J Dai
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - J M Keller
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - A Hua
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - J L Sottnik
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - G Shelley
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - C L Hall
- Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - S I Park
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Z Yao
- Department of Immunology, Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Educational Ministry, Tianjin Medical University, Tianjin, China
| | - J Zhang
- Center for Translational Medical Research, Guangxi Medical University, Guangxi, China
| | - L K McCauley
- 1] Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA [2] Department of Pathology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - E T Keller
- 1] Department of Urology, School of Medicine, University of Michigan, Ann Arbor, MI, USA [2] Department of Pathology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
9
|
Sato K, Lee JW, Sakamoto K, Iimura T, Kayamori K, Yasuda H, Shindoh M, Ito M, Omura K, Yamaguchi A. RANKL synthesized by both stromal cells and cancer cells plays a crucial role in osteoclastic bone resorption induced by oral cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:1890-9. [PMID: 23499553 DOI: 10.1016/j.ajpath.2013.01.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 11/29/2012] [Accepted: 01/15/2013] [Indexed: 11/25/2022]
Abstract
The molecular mechanisms underlying bone destruction by invading oral cancer are not well understood. Using IHC, we demonstrated that receptor activator of nuclear factor-κB ligand (RANKL)-positive fibroblasts and cancer cells were located at sites of bone invasion in human oral cancers. HSC3 and HO-1-N-1, human oral cancer cell lines, expressed RANKL and stimulated Rankl expression in the UAMS-32 murine osteoblastic cell line. We discriminated the roles of RANKL synthesized by stromal cells and cancer cells in cancer-associated bone resorption by using species-specific RANKL antibodies against murine RANKL and human RANKL, respectively. Osteoclastogenesis induced by the conditioned medium of HSC3 and HO-1-N-1 cells in a co-culture of murine bone marrow cells and UAMS-32 cells was inhibited by the addition of antibodies against either mouse or human RANKL. HSC3-induced bone destruction was greatly inhibited by the administration of anti-mouse RANKL antibody in a xenograft model. HO-1-N-1-induced bone destruction was inhibited by the administration of either anti-mouse or anti-human RANKL antibody. Bone destruction induced by the transplantation of human RANKL-overexpressing cells (HSC3-R2) was greatly inhibited by the injection of anti-human RANKL antibody. The present study revealed that RANKL produced by both stromal and cancer cells is involved in oral cancer-induced osteoclastic bone resorption. These results provide important information for understanding the cellular and molecular basis of cancer-associated bone destruction and the mechanism of action underlying RANKL antibody (denosumab) therapy.
Collapse
Affiliation(s)
- Kiyoshi Sato
- Section of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Todenhöfer T, Hennenlotter J, Schmiedel BJ, Hohneder A, Grimm S, Kühs U, Salih HR, Bühring HJ, Fehm T, Gakis G, Blumenstock G, Aufderklamm S, Schilling D, Stenzl A, Schwentner C. Alterations of the RANKL pathway in blood and bone marrow samples of prostate cancer patients without bone metastases. Prostate 2013; 73:162-8. [PMID: 22715006 DOI: 10.1002/pros.22551] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 05/29/2012] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The receptor activator of the NF-kB ligand (RANKL) pathway is a key mediator of prostate cancer (PC)-induced bone disease. However, little is known about this pathway in patients with non-metastatic PC. We aimed to investigate whether changes of RANKL, its inhibitor osteoprotegerin (OPG) and bone marrow-mesenchymal stromal cells (BM-MSCs) occur in PC patients without manifest bone metastases. PATIENTS AND METHODS We determined OPG and soluble RANKL (sRANKL) in serum and corresponding bone marrow (BM) samples of 140 patients before radical prostatectomy by enzyme-linked immunosorbent assay (ELISA). As control serum samples of 50 patients with benign prostate hyperplasia were analyzed. BM mononuclear cells (BMNCs) of 16 PC patients were analyzed for expression of RANKL and CD271 (as marker for MSCs) by flow cytometry. RESULTS PC patients had significantly lower serum levels of OPG compared to BPH patients (P = 0.007), whereas no differences were observed for serum sRANKL (P = 0.74). Both OPG and sRANKL concentrations of serum and corresponding BM samples correlated significantly (P < 0.0001 each). Interestingly, in PC patients, lower serum and BM OPG levels were associated with a higher proportion of BM-MSCs (P = 0.04 and 0.0016, respectively). No correlations were observed for sRANKL, OPG, BM-MSCs, and established risk parameters of PC. DISCUSSION The results of the study indicate that localized PC is associated with early specific changes of the RANKL pathway in serum and bone marrow (BM). These changes might be part of the pre-metastatic niche of PC and implicate a potential benefit of RANKL inhibition in patients with localized PC.
Collapse
Affiliation(s)
- Tilman Todenhöfer
- Department of Urology, University Hospital Tuebingen, Tuebingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Sanz AB, Sanchez-Niño MD, Carrasco S, Manzarbeitia F, Ruiz-Andres O, Selgas R, Ruiz-Ortega M, Gonzalez-Enguita C, Egido J, Ortiz A. Inflammatory cytokines and survival factors from serum modulate tweak-induced apoptosis in PC-3 prostate cancer cells. PLoS One 2012; 7:e47440. [PMID: 23077618 PMCID: PMC3471822 DOI: 10.1371/journal.pone.0047440] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/17/2012] [Indexed: 12/24/2022] Open
Abstract
Tumor necrosis factor-like weak inducer of apoptosis (TWEAK, TNFSF12) is a member of the tumor necrosis factor superfamily. TWEAK activates the Fn14 receptor, and may regulate cell death, survival and proliferation in tumor cells. However, there is little information on the function and regulation of this system in prostate cancer. Fn14 expression and TWEAK actions were studied in two human prostate cancer cell lines, the androgen-independent PC-3 cell line and androgen-sensitive LNCaP cells. Additionally, the expression of Fn14 was analyzed in human biopsies of prostate cancer. Fn14 expression is increased in histological sections of human prostate adenocarcinoma. Both prostate cancer cell lines express constitutively Fn14, but, the androgen-independent cell line PC-3 showed higher levels of Fn14 that the LNCaP cells. Fn14 expression was up-regulated in PC-3 human prostate cancer cells in presence of inflammatory cytokines (TNFα/IFNγ) as well as in presence of bovine fetal serum. TWEAK induced apoptotic cell death in PC-3 cells, but not in LNCaP cells. Moreover, in PC-3 cells, co-stimulation with TNFα/IFNγ/TWEAK induced a higher rate of apoptosis. However, TWEAK or TWEAK/TNFα/IFNγ did not induce apoptosis in presence of bovine fetal serum. TWEAK induced cell death through activation of the Fn14 receptor. Apoptosis was associated with activation of caspase-3, release of mitochondrial cytochrome C and an increased Bax/BclxL ratio. TWEAK/Fn14 pathway activation promotes apoptosis in androgen-independent PC-3 cells under certain culture conditions. Further characterization of the therapeutic target potential of TWEAK/Fn14 for human prostate cancer is warranted.
Collapse
Affiliation(s)
| | | | - Susana Carrasco
- Nefrologia, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid and Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| | - Felix Manzarbeitia
- Anatomia Patologica, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Olga Ruiz-Andres
- Nefrologia, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid and Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| | | | - Marta Ruiz-Ortega
- Nefrologia, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid and Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| | | | - Jesus Egido
- Nefrologia, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid and Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| | - Alberto Ortiz
- Nefrologia, IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid and Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| |
Collapse
|
12
|
Lupp A, Klenk C, Röcken C, Evert M, Mawrin C, Schulz S. Immunohistochemical identification of the PTHR1 parathyroid hormone receptor in normal and neoplastic human tissues. Eur J Endocrinol 2010; 162:979-86. [PMID: 20156969 DOI: 10.1530/eje-09-0821] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Parathyroid hormone (PTH) is a crucial regulator of calcium homoeostasis in humans. Although it is well known that PTH acts primarily on kidney and bone, the precise cellular and subcellular sites of PTH action have not been visualised in human tissues. METHOD We developed and characterised a novel anti-peptide antibody to the carboxy-terminal region of the human PTH receptor type 1 (PTHR1). Specificity of the antiserum was demonstrated by i) detection of a broad band migrating at M(r) 85,000-95,000 in western blots of membranes from human kidney and PTHR1-transfected cells; ii) cell surface staining of PTHR1-transfected cells; iii) translocation of PTHR1 receptor immunostaining after agonist exposure; and iv) abolition of tissue immunostaining by preadsorption of the antibody with its immunising peptide. The distribution of PTHR1 receptors was investigated in 320 human tumours and their tissues of origin. RESULTS In the kidney, PTHR1 receptors were predominantly detected at the basolateral plasma membrane of epithelial cells in the proximal and distal tubules but not in the thin limbs of Henle, collecting ducts or glomeruli. In bone, PTHR1 receptors were detected as discrete plasma membrane staining of osteocytes and osteoblasts, whereas osteoclasts remained unstained. In addition, PTHR1 was found in the gut and in a number of neoplastic tissues including colorectal carcinoma, prostate cancer, renal cell carcinoma and osteosarcoma. CONCLUSION This is the first localisation of PTHR1 receptors in human tissues at the cellular level. The overexpression of PTHR1 receptors may provide a molecular basis for efficient targeting of human tumours with radiolabelled PTH analogues.
Collapse
Affiliation(s)
- Amelie Lupp
- Department of Pharmacology and Toxicology, Friedrich-Schiller-University, Jena, Germany
| | | | | | | | | | | |
Collapse
|
13
|
Tollefson MK, Blute ML, Rangel LJ, Bergstralh EJ, Boorjian SA, Karnes RJ. The effect of Gleason score on the predictive value of prostate-specific antigen doubling time. BJU Int 2009; 105:1381-5. [PMID: 19863524 DOI: 10.1111/j.1464-410x.2009.08976.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the influence of the pathological Gleason score on the predictive value of the prostate-specific antigen (PSA) doubling time (DT), as this variable predicts a patient's risk of disease progression both before and after definitive therapy for prostate cancer, and there is an inverse correlation between the Gleason score and PSA production. PATIENTS AND METHODS We evaluated all men treated with radical prostatectomy (RP) between 1990 and 1999 who did not receive neoadjuvant or adjuvant therapy. We identified 2296 patients who had multiple PSA values available before RP, and 1323 who had biochemical recurrence after RP and had at least two PSA values available before starting secondary therapy. Systemic progression and cancer-specific survival (CSS) rates were estimated using the Kaplan-Meier method and Cox proportional hazard regression models. RESULTS A PSA DT of <18 vs >18 months predicted a lower 10-year systemic progression-free survival for patients with tumours having a pathological Gleason score of <7 (98% vs 99%, P = 0.005), 7 (82% vs 91%, P = 0.003) and 8-10 (57% vs 73%, P = 0.042). A PSA DT after RP of <12 months was significantly associated with a lower 10-year systemic progression-free survival for patients with tumours having a Gleason score of <7 (77% vs 94%, P < 0.001) and 7 (61% vs 86%, P < 0.001), but not 8-10 (61% vs 75%, P = 0.11). The ability of PSA DT before and after RP to predict systemic progression and CSS decreased with increasing Gleason score. CONCLUSIONS The PSA DT remains associated with outcome both before and after RP across increasing pathological Gleason scores, although the predictive ability of PSA DT is diminished in Gleason 8-10 cancers.
Collapse
|
14
|
Alonso V, Pérez-Martínez FC, Calahorra FJ, Esbrit P. Phytoestrogen modulation of bone-related cytokines and its impact on cell viability in human prostate cancer cells. Life Sci 2009; 85:421-30. [PMID: 19632246 DOI: 10.1016/j.lfs.2009.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 06/30/2009] [Accepted: 07/09/2009] [Indexed: 10/20/2022]
Abstract
AIMS Prostate cancer (PCa) has a high propensity to metastasize to the bone. PCa cells produce several bone-related factors, namely parathyroid hormone related protein (PTHrP), its PTH type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of NF-kappa B ligand (RANKL). The effects of these factors might explain, at least in part, the ability of PCa cells to grow in and interact with bone. MAIN METHODS We first analyzed the expression of the aforementioned factors (by western blot and flow cytometry), and their modulation by the phytoestrogens genistein and daidzein (as potential anti-tumoral agents), in human PCa cells in vitro. We also assessed the impact of these osteomimetic factors on PCa cell viability (by propidium iodide staining and flow cytometry, and trypan blue staining). KEY FINDINGS Genistein and daidzein, at nM range, increased both the PTHrP/PTH1R system and the OPG/RANKL protein ratio, while genistein and, to a lesser extent, daidzein, at >microM doses, inhibited cell viability in PCa cells. Both N- and C-terminal domains of PTHrP inhibited genistein-induced cell death by modulating transcription factor Runx-2 and the Bcl-2/Bax protein ratio in PCa cells. SIGNIFICANCE Our findings indicate that high doses of genistein and daidzein cause PCa cell death. On the other hand, low doses of these phytoestrogens induce some osteomimetic features in PCa cells with putative impact on PCa development.
Collapse
Affiliation(s)
- V Alonso
- Laboratorio de Metabolismo Mineral y Oseo, Fundación Jiménez Díaz (Capio Group), Madrid, Spain.
| | | | | | | |
Collapse
|
15
|
Expression of parathyroid hormone-related protein in the partially obstructed and reversed rabbit bladder. Int Urol Nephrol 2008; 41:505-11. [DOI: 10.1007/s11255-008-9485-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 09/23/2008] [Indexed: 01/05/2023]
|
16
|
Abstract
Cancer is one of the major leading causes of death all over the world. Primary and secondary bone tumors can significantly deteriorate the quality of life (QOL) and the activity of daily living (ADL) of the patients. These unwelcome diseases become a social and economic burden seriously. Thus, more effective therapies for both primary and secondary bone tumors are actually required. Bone homeostasis depends on the strictly balanced activities between bone formation by osteoblasts and bone resorption by osteoclasts. Imbalance of bone formation and resorption results in various bone diseases. Both primary and secondary bone tumors develop in the unique environment bone, it is therefore necessary to understand bone cell biology in tumoral bone environment. Recent findings strongly revealed the significant involvement of the receptor activator of nuclear factor kappaB ligand (RANKL)/RANK/osteoprotegerin (OPG) triad, the key regulators of bone remodeling in bone oncology. Indeed, RANKL/RANK blocking successfully prevented the development of bone metastases. Furthermore, some cancer cells express RANK which is involved in tumor cell migration. Thus, the regulation of this triad will be a rational, encouraged therapeutic hot spot in bone oncology. In this review, we summarize the accumulating knowledge of the RANKL/RANK/OPG triad and discuss about its therapeutic capability in primary and secondary bone tumors.
Collapse
Affiliation(s)
- Kosei Ando
- Department of Orthopaedic Surgery
Shiga University of Medical ScienceOtsu, Shiga, 520-2192,JP
| | - Kanji Mori
- Physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives
INSERM : ERI7IFR26Université de Nantes : EA3822Faculte de Medecine
1, Rue Gaston Veil
44035 NANTES CEDEX 1,FR
| | - Françoise Rédini
- Physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives
INSERM : ERI7IFR26Université de Nantes : EA3822Faculte de Medecine
1, Rue Gaston Veil
44035 NANTES CEDEX 1,FR
| | - Dominique Heymann
- Physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives
INSERM : ERI7IFR26Université de Nantes : EA3822Faculte de Medecine
1, Rue Gaston Veil
44035 NANTES CEDEX 1,FR
| |
Collapse
|
17
|
Schwartz GG. Prostate cancer, serum parathyroid hormone, and the progression of skeletal metastases. Cancer Epidemiol Biomarkers Prev 2008; 17:478-83. [PMID: 18349265 DOI: 10.1158/1055-9965.epi-07-2747] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bony metastases from prostate cancer are a significant cause of morbidity and mortality. These metastases are predominantly blastic (bone-forming) and commonly cause increased serum levels of parathyroid hormone (PTH) as calcium ions are transferred from serum into blastic bone. The epidemiologic and clinical significance of secondary hyperparathyroidism in advanced prostate cancer have not been widely appreciated. Prostate cancer bony metastases show increased expression of the PTH receptor (PTH-IR) and PTH promotes the growth and invasiveness of prostate cancer cells in bone. Thus, blastic metastases appear to induce a "vicious cycle" in which PTH resorbs normal bone to support the growth of blastic bone. Recognition of the potential role of PTH in the progression of skeletal metastases suggests novel opportunities for prostate cancer secondary prevention. In particular, we propose that suppressing serum PTH in advanced prostate cancer may reduce morbidity by decreasing fractures and pain caused by bone resorption and may reduce mortality by retarding the progression of metastatic disease.
Collapse
Affiliation(s)
- Gary G Schwartz
- Departments of Cancer Biology and Epidemiology and Prevention, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
| |
Collapse
|
18
|
Berruti A, Tucci M, Mosca A, Ardine M, Poggio M, Saini A, Russo L, Vana F, Dogliotti L. Could the efficacy of docetaxel in prostate cancer patients be potentiated by concomitant high-dose calcitriol administration? J Clin Oncol 2008; 26:1900-1; author reply 1901-2. [PMID: 18398157 DOI: 10.1200/jco.2007.15.7941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
19
|
Keller ET, Dai J, Escara-Wilke J, Hall CL, Ignatoski K, Taichman RS, Keller J. New trends in the treatment of bone metastasis. J Cell Biochem 2008; 102:1095-102. [PMID: 17955492 DOI: 10.1002/jcb.21540] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bone metastasis is often the penultimate harbinger of death for many cancer patients. Bone metastases are often associated with fractures and severe pain resulting in decreased quality of life. Accordingly, effective therapies to inhibit the development or progression of bone metastases will have important clinical benefits. To achieve this goal understanding the mechanisms through which bone metastases develop and progress may provide targets to inhibit the metastases. In the past few years, there have been advances in both understanding the mechanisms through which bone metastases develop and how they impact bone remodeling. Additionally, gains in promising clinical strategies to target bone metastases have been developed. In this prospectus, we will discuss some of these advances.
Collapse
Affiliation(s)
- Evan T Keller
- Department of Urology, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | | | | | | | | | | | | |
Collapse
|
20
|
Waterman EA, Cross NA, Lippitt JM, Cross SS, Rehman I, Holen I, Hamdy FC, Eaton CL. The antibody MAB8051 directed against osteoprotegerin detects carbonic anhydrase II: implications for association studies with human cancers. Int J Cancer 2007; 121:1958-1966. [PMID: 17631639 DOI: 10.1002/ijc.22946] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A commonly used monoclonal antibody targeting osteoprotegerin (OPG), MAB8051, detects a truncated protein species in breast and prostate cancer cell lysates. OPG expression has been reported to contribute to cell survival of both of these cancers. We hypothesised that the truncated protein represented a unique tumour-associated OPG isoform. However, here we show that the truncated protein identified by MAB8051 in cancer cell lines is carbonic anhydrase II (CA II), also implicated in tumour biology. We clearly demonstrate cross-reactivity of this OPG antibody in western blots. OPG and CA II RNA-interference studies confirmed the identity of the bands. We show almost identical staining patterns between MAB8051 and CA II immunohistochemistry of different human tissue types and human tumour types using serial sections. We conclude that care should be exercised using this antibody for immunohistochemistry studies, without additional in situ hybridisation, or parallel use of other OPG-specific antibodies.
Collapse
Affiliation(s)
- Elizabeth A Waterman
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Neil A Cross
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Jenifer M Lippitt
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Simon S Cross
- Academic Unit of Pathology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Ishtiaq Rehman
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Ingunn Holen
- Clinical Oncology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Freddie C Hamdy
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Colby L Eaton
- Academic Unit of Urology, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| |
Collapse
|
21
|
Morrissey C, Kostenuik PL, Brown LG, Vessella RL, Corey E. Host-derived RANKL is responsible for osteolysis in a C4-2 human prostate cancer xenograft model of experimental bone metastases. BMC Cancer 2007; 7:148. [PMID: 17683568 PMCID: PMC2034387 DOI: 10.1186/1471-2407-7-148] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 08/03/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND C4-2 prostate cancer (CaP) cells grown in mouse tibiae cause a mixed osteoblastic/osteolytic response with increases in osteoclast numbers and bone resorption. Administration of osteoprotegerin (OPG) blocks these increases, indicating the critical role of RANKL in osteolysis in this model. The objective of our study was to investigate whether RANKL expressed by tumor cells (human origin) directly stimulates osteolysis associated with the growth of these cells in bone or whether the increased osteolysis is caused by RANKL expressed by the host environment cells (murine origin). The relative contribution of tumor-vs. host-derived RANKL has been difficult to establish, even with human xenografts, because murine and human RANKL are both capable of stimulating osteolysis in mice, and the RANKL inhibitors used to date (OPG and RANK-Fc) inhibit human and murine RANKL. METHODS To address this question we used a neutralizing, antibody (huRANKL MAb), which specifically neutralizes the biological activities of human RANKL and thereby the contribution of C4-2 derived RANKL in this tibial injection model of experimental bone metastases. RESULTS Administration of huRANKL MAb did not inhibit the osteolytic response of the bone to these cells, or affect the establishment and growth of the C4-2 tumors in this environment. CONCLUSION In conclusion, our results suggest that in this model, murine RANKL and not the tumor-derived human RANKL is the mediator of the osteolytic reaction associated with C4-2 growth in bone. We hypothesize that C4-2 cells express other factor/s inducing host production of RANKL, thereby driving tumor-associated osteolysis.
Collapse
Affiliation(s)
- Colm Morrissey
- Department of Urology, University of Washington, Seattle, WA, USA
| | | | - Lisha G Brown
- Department of Urology, University of Washington, Seattle, WA, USA
| | - Robert L Vessella
- Department of Urology, University of Washington, Seattle, WA, USA
- Puget Sound VA Medical Center, Seattle, WA, USA
| | - Eva Corey
- Department of Urology, University of Washington, Seattle, WA, USA
| |
Collapse
|
22
|
Abstract
The maintenance of skeletal integrity in a healthy individual requires a balanced regulation of the processes of bone formation, mediated by osteoblasts, and bone resorption, mediated by osteoclasts. This balanced process of bone remodeling becomes co-opted in the skeleton by tumor cells and this dramatically accelerates the process of remodeling and disrupts the normal equilibrium resulting in a spectrum of osteolytic to osteoblastic bone lesions. Certain tumor types, such as breast and prostate, frequently metastasize to the bone. It is now widely understood that the molecular triad--receptor activator of NF-kappaB ligand (RANKL), its receptor RANK, and the endogenous soluble RANKL inhibitor, osteoprotegerin (OPG)--play direct and essential roles in the formation, function, and survival of osteoclasts. Osteoclastic bone resorption contributes to the majority of skeletal sequelae, or skeletal-related events (SREs), in patients with bone metastases. In addition, osteoclastic bone resorption also contributes to the establishment of tumors in the skeleton. Therefore, blocking osteoclast activity and differentiation via RANKL inhibition may not only provide a beneficial treatment for skeletal complications of malignancy, but may also prevent bone metastases. In this review, we will first describe the operative role of osteoclasts and the RANK/RANKL/OPG triad in the pathophysiology of cancer-induced bone diseases, specifically solid tumor metastases to the bone. Secondly, we will describe a therapeutic approach that specifically targets the RANKL molecule.
Collapse
Affiliation(s)
- William C Dougall
- Department of Cancer Biology, Amgen Washington, 1201 Amgen Court West, Seattle, WA 98119, USA.
| | | |
Collapse
|