Transferts graisseux au niveau du sein: implications oncologiques.
NIZET, Jean-Luc ; Gonzalez, Arnaud ; Peulen, Olivier et al
in Revue Médicale de Liège (2011), 66(5-6), 362-6
Autologous fat grafting for breast is increasing dramatically. This fat injection needs accurate technical conditions, and shows very good and long-lasting clinical results. Nevertheless, in breast ... [more ▼]
Autologous fat grafting for breast is increasing dramatically. This fat injection needs accurate technical conditions, and shows very good and long-lasting clinical results. Nevertheless, in breast conservative treatment sequellae, fat injection could lead to difficulties in breast imaging, but also there is some concerns about the potential oncologic risks of these procedures. [less ▲]Detailed reference viewed: 101 (11 ULg)
Dentin Matrix Protein 1 induces membrane expression of VE-cadherin on endothelial cells and inhibits VEGF-induced angiogenesis by blocking VEGFR-2 phosphorylation.
Pirotte, Sophie ; Lamour, Virginie ; Lambert, Vincent et al
in Blood (2011), 117(8), 2515-26
Dentin matrix protein 1 (DMP1) is a member of the Small Integrin-Binding LIgand N-linked Glycoproteins (SIBLINGs) family, a group of proteins initially described as mineralized extracellular matrices ... [more ▼]
Dentin matrix protein 1 (DMP1) is a member of the Small Integrin-Binding LIgand N-linked Glycoproteins (SIBLINGs) family, a group of proteins initially described as mineralized extracellular matrices components. More recently, SIBLINGs have been implicated in several key steps of cancer progression, including angiogenesis. Although pro-angiogenic activities have been demonstrated for two SIBLINGs, the role of DMP1 in angiogenesis has not been addressed yet. We demonstrated that this extracellular matrix protein induced the expression of VE-cadherin, a key regulator of intercellular junctions and contact inhibition of growth of endothelial cells that is also known to modulate VEGFR-2 activity, the major high affinity receptor for VEGF. DMP1 induced VE-cadherin and p27(Kip1) expression followed by cell cycle arrest in human umbilical vein endothelial cells (HUVEC) in a CD44-dependent manner. VEGF-induced proliferation, migration and tubulogenesis responses were specifically blocked upon DMP1 pre-treatment of HUVEC. Indeed, subsequently to VE-cadherin induction, DMP1 inhibited VEGFR-2 phosphorylation and Src-mediated signaling. However, DMP1 did not interfere with bFGF-induced angiogenesis. In vivo, DMP1 significantly reduced laser-induced choroidal neovascularization lesions and tumor-associated angiogenesis. These data enable us to put DMP1 on the angiogenic chessboard for the first time and to identify this protein as a new specific inhibitor of VEGF-induced angiogenesis. [less ▲]Detailed reference viewed: 194 (43 ULg)
Role of the Focal Adhesion Protein Kindlin-1 in Breast Cancer Growth and Lung Metastasis.
; ; et al
in Journal of the National Cancer Institute (2011), 103
Background Fermitin family member 1 (FERMT1, Kindlin-1) is an epithelial-specific regulator of integrin functions and is associated with Kindler syndrome, a genetic disorder characterized by skin ... [more ▼]
Background Fermitin family member 1 (FERMT1, Kindlin-1) is an epithelial-specific regulator of integrin functions and is associated with Kindler syndrome, a genetic disorder characterized by skin blistering, atrophy, and photosensitivity. However, the possible role of kindlin-1 in cancer remains unknown. Methods Kindlin-1 expression was quantified in several human cancers using quantitative real-time polymerase chain reaction and published microarray datasets. The association between kindlin-1 expression and patient metastasis-free survival (N = 516) was assessed with Kaplan-Meier analyses. Effects of ectopic expression or silencing of kindlin-1 on cell signaling, migration, and invasion were assessed in human breast cancer cell lines using western blotting, immunofluorescence, wound healing assays, and invasion on Matrigel or type I collagen substrates. Breast tumor growth and lung metastasis were evaluated in 12-week-old female BALB/c mice (10 controls and six Kindlin-1-knockdown mice). All statistical tests were two-sided. Results Kindlin-1 expression was consistently higher in tumors than in normal tissues in various cancer types metastasizing to the lungs, including colon and bladder cancer. Kindlin-1 expression was associated with metastasis-free survival in both breast and lung adenocarcinoma (breast cancer: hazard ratio of lung metastasis = 2.55, 95% confidence intervals [CI] = 1.39 to 4.69, P = .001; lung cancer: hazard ratio of metastasis = 1.96, 95% CI = 1.25 to 3.07, P = .001). Overexpression of kindlin-1 induced changes indicating epithelial-mesenchymal transition and transforming growth factor beta (TGFbeta) signaling, constitutive activation of cell motility, and invasion (number of migrating cells, Kindlin-1 cells vs control, mean = 164.66 vs 19.00, difference = 145.6, 95% CI = 79.1 to 212.2, P = .004; invasion rate, Kindlin-1-cells vs control = 9.65% vs 1.92%, difference = 7.73%, 95% CI = 4.75 to 10.70, P < .001). Finally, Kindlin-1 depletion in an orthotopic mouse model statistically significantly inhibited breast tumor growth (P < .001) and lung metastasis (P = .003). Conclusion These results suggest a role for kindlin-1 in breast cancer lung metastasis and lung tumorigenesis and advance our understanding of kindlin-1 as a regulator of TGFbeta signaling, offering new avenues for therapeutic intervention against cancer progression. [less ▲]Detailed reference viewed: 29 (8 ULg)
Nitrogen-containing bisphosphonates can inhibit angiogenesis in vivo without the involvement of farnesyl pyrophosphate synthase.
; ; Bellahcene, Akeila et al
in Bone (2011), 48(2), 259-66
Nitrogen-containing bisphosphonates (N-BPs) are widely used to block bone destruction associated with bone metastasis because they are effective inhibitors of osteoclast-mediated bone resorption. More ... [more ▼]
Nitrogen-containing bisphosphonates (N-BPs) are widely used to block bone destruction associated with bone metastasis because they are effective inhibitors of osteoclast-mediated bone resorption. More specifically, once internalized by osteoclasts, N-BPs block the activity of farnesyl pyrophosphate synthase (FPPS), a key enzyme in the mevalonate pathway. In addition to their antiresorptive activity, preclinical evidence shows that N-BPs have antiangiogenic properties. However, the exact reasons for which N-BPs inhibit angiogenesis remain largely unknown. Using different angiogenesis models, we examined here the effects of zoledronate, risedronate and three structural analogs of risedronate (NE-58025, NE-58051 and NE-10790) with lower potencies to inhibit FPPS activity. Risedronate and zoledronate were much more potent than NE-compounds at inhibiting both endothelial cell proliferation in vitro and vessel sprouting in the chicken egg chorioallantoic membrane (CAM) assay. In addition, only risedronate and zoledronate inhibited the revascularization of the prostate gland in testosterone-stimulated castrated rats. Moreover, as opposed to NE-compounds, risedronate and zoledronate induced intracellular accumulation of isopentenyl pyrophosphate (IPP) in endothelial cells by blocking the activity of the IPP-consuming enzyme FPPS. Thus, these results indicated that N-BPs inhibited angiogenesis in a FPPS-dependent manner. However, drug concentrations used to inhibit angiogenesis, both in vitro and in the CAM and prostate gland assays, were high. In contrast, a low concentration of risedronate (1 muM) was sufficient to inhibit blood vessel formation in the ex vivo rat aortic ring assay. Moreover, NE-58025 (which had a 7-fold lower potency than risedronate to inhibit FPPS activity) was as effective as risedronate to reduce angiogenesis in the rat aortic ring assay. In conclusion, our results suggest that low concentrations of N-BPs inhibit angiogenesis in a FPPS-independent manner, whereas higher drug concentrations were required to inhibit FPPS activity in vivo. [less ▲]Detailed reference viewed: 178 (12 ULg)
Histone deacetylases: anti-angiogenic targets in cancer therapy.
Mottet, Denis ; Castronovo, Vincenzo
in Current Cancer Drug Targets (2010), 10(8), 898-913
Judah Folkman was the first in 1971 to observe and report that cancer growth and dissemination were dependent on angiogenesis - the formation of new blood vessels from pre-existing vasculature. For almost ... [more ▼]
Judah Folkman was the first in 1971 to observe and report that cancer growth and dissemination were dependent on angiogenesis - the formation of new blood vessels from pre-existing vasculature. For almost 40 years, this concept has inspired generations of researchers to identify anti-angiogenic molecules that could be used therapeutically to stop blood vessels formation and starve tumors of nutrients and oxygen. Tumor angiogenesis requires complex cellular and molecular interactions between endothelial and cancer cells. In response to external stimuli such as hypoxia, cancer cells secrete pro-angiogenic factors into the extracellular matrix that activate the surrounding endothelial cells to proliferate, migrate and form new blood vessels. So, vascularization of malignant lesions depends on the expression of specific genes in both endothelial and tumor cells and accumulating evidences shows that several members of the histone deacetylase (HDAC) family play key roles in the regulation of these genes. Indeed, numerous in vitro and in vivo studies demonstrated that inhibitors of HDAC modulate angiogenic gene expression in both endothelial and cancer cells and disturb the delicate and complex balance between the collective action of pro-angiogenic factors and angiogenesis inhibitors. Thus, HDAC are currently recognized as promising targets for the development of anti-cancer drugs. This review is an effort to present and discuss the role, functions and mechanisms of action of HDAC during tumor-driven angiogenesis as well as a brief summary of the clinical status of the main HDAC inhibitors (HDACi) currently under development in cancer therapy. [less ▲]Detailed reference viewed: 97 (17 ULg)
Novel post-digest isotope coded protein labeling method for phospho- and glycoproteome analysis
Fleron, Maximilien ; Greffe, Yannick ; Musmeci, Davide et al
in Journal of Proteomics (2010), 73(10), 1986-2005
In the field of proteomics there is an apparent lack of reliable methodology for quantification of posttranslational modifications. Present study offers a novel post-digest ICPL quantification strategy ... [more ▼]
In the field of proteomics there is an apparent lack of reliable methodology for quantification of posttranslational modifications. Present study offers a novel post-digest ICPL quantification strategy directed towards characterization of phosphorylated and glycosylated proteins. The value of the method is demonstrated based on the comparison of two prostate related metastatic cell lines originating from two distinct metastasis sites (PC3 and LNCaP). The method consists of protein digestion, ICPL labeling, mixing of the samples, PTM enrichment and MS-analysis. Phosphorylated peptides were isolated using TiO(2), whereas the enrichment of glycosylated peptides was performed using hydrazide based chemistry. Isolated PTM peptides were analyzed along with non enriched sample using 2D-(SCX-RP)-Nano-HPLC-MS/MS instrumentation. Taken together the novel ICPL labeling method offered a significant improvement of the number of identified (∼600 individual proteins) and quantified proteins (>95%) in comparison to the classical ICPL method. The results were validated using alternative protein quantification strategies as well as label-free MS quantification method. On the biological level, the comparison of PC3 and LNCaP cells has shown specific modulation of proteins implicated in the fundamental process related to metastasis dissemination. Finally, a preliminary study involving clinically relevant autopsy cases reiterated the potential biological value of the discovered proteins. [less ▲]Detailed reference viewed: 71 (10 ULg)
Novel Relative ICPL Based Quantitative Phospho- and Glycoproteome Analysis Method
Fleron, Maximilien ; Greffe, Yannick ; Massart, Anne-Cécile et al
Poster (2010, April 16)
Large scale proteomic analysis remains challenging partially because proteins are inhomogeneous and often influenced by a variety of structural modifications. In particular, these specific chemical ... [more ▼]
Large scale proteomic analysis remains challenging partially because proteins are inhomogeneous and often influenced by a variety of structural modifications. In particular, these specific chemical modifications called posttranslational modifications (PTM) are crucial determinants for the protein function and biological role. Up to now there have been a growing number of studies describing the enrichment and identification of PTM. However, a significant dearth of data offering a reliable methodology for PTM quantification does exist. The present work aims at developing a label based protein PTM quantification strategy and demonstrating its value on comparative analysis of cells originating from two distinct prostate metastasis sites. PC3 and LNCaP cells isolated from bone and lymph node prostate cancer metastasis sites respectively, were lysed and spiked with three non-human proteins serving as internal standards. Following this, the samples were reduced and alkylated, digested with trypsin and subjected to peptide ICPL (isotope coded protein label) labeling. The two peptide containing samples were joined together followed by the affinity isolation of phospho- (using TiO2 metal affinity chromatography) and glycopeptides (oxidized glycans were bound on hydrazide resin). The enriched fraction as well as the flow-through were analyzed on a 2D-(SCX and C18-RP)-nano-HPLC system. The peptide identification and quantification was conducted using electrospray ion-trap mass spectrometer (Bruker, HCT-ultra). Validation of the differentially modulated proteins was conducted in several biological and technical replicates using the label free MSe based quantification strategy. This PTM based, novel relative protein quantification using post-digest ICPL has detected over 598 individual proteins. Of these more than 95 % have been successfully quantified. PTM enrichment methodologies allowed an isolation rate of 91 % and 50 % for phosphorylated and glycosylated proteins respectively. The detailed comparison of PC3 and LNCaP cells has shown specific overexpression of selected proteins indicating differences between these two prostate metastatic cell lines. Several of these modulated proteins have been previously described to be related to prostate cancer (e.g. annexin A2 and vimentin) while others could be considered as potentially novel. These proteins might be implicated in the fundamental process related to metastasis dissemination. However, because of the known discrepancy between cell systems and clinical material, the present study can be regarded only as a step towards elucidation of these complex interactions. [less ▲]Detailed reference viewed: 45 (5 ULg)
Netrin-1 Mediates Early Events in Pancreatic Adenocarcinoma Progression, Acting on Tumor and Endothelial Cells.
; ; et al
in Gastroenterology (2010), 138(4), 1595-606
BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers. It is characterized by substantial tumor cell invasion and early-stage metastasis. We developed an in vivo ... [more ▼]
BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers. It is characterized by substantial tumor cell invasion and early-stage metastasis. We developed an in vivo model to analyze interactions between cancer and stromal cells during early stages of PDAC. METHODS: Human pancreatic adenocarcinoma cells were grafted onto the chick chorioallantoic membrane (CAM). Human and chicken GeneChips were used simultaneously to study gene regulation during PDAC cell invasion. Bioinformatic analysis was used to identify human orthologs and cell specificity of gene expression. The effects of netrin-1 encoded by NTN1 were investigated in adhesion, invasion, and apoptosis assays. The effects of NTN1 silencing with small interfering RNAs were investigated in PDAC cells in vivo. NTN1 expression was measured in human PDAC samples. RESULTS: PDAC cells rapidly invade the CAM stroma and remodel the CAM vasculature. More than 870 stromal genes were up-regulated by >2-fold; the angiogenesis regulators vascular endothelial growth factor D, thrombospondin 1, and CD151 were among the most highly regulated genes. Silencing of tumor cell NTN1, which is up-regulated 4-fold in the PDAC model, inhibited tumor cell invasion in vivo. Netrin-1 conferred apoptosis resistance to tumor and endothelial cells in vitro, induced their invasion, and provided an adhesive substrate for tumor cells. NTN1 and its gene product are strongly overexpressed in human PDAC samples. CONCLUSIONS: We developed a useful tool to study the invasive mechanisms of early-stage PDAC. Netrin-1 might be an important regulator of pancreatic tumor growth that functions in tumor and endothelial cells. [less ▲]Detailed reference viewed: 60 (7 ULg)
Selective osteopontin knockdown exerts anti-tumoral activity in a human glioblastoma model.
Lamour, Virginie ; ; et al
in International Journal of Cancer = Journal International du Cancer (2010), 126
Osteopontin (OPN), a member of the SIBLING (Small Integrin-Binding LIgand N-linked Glycoprotein) family, is overexpressed in human glioblastoma. Higher levels of OPN expression correlate with increased ... [more ▼]
Osteopontin (OPN), a member of the SIBLING (Small Integrin-Binding LIgand N-linked Glycoprotein) family, is overexpressed in human glioblastoma. Higher levels of OPN expression correlate with increased tumor grade and enhanced migratory capacity of tumor cells. Based on these observations, we explored the possibility that knocking down OPN expression in glioblastoma cells could exert an anti-tumoral activity using an avian in vivo glioblastoma model that mimics closely human gliobastoma. Human U87-MG glioma cells transfected with specific anti-OPN small interfering RNAs (siRNAs) were grafted onto the chicken chorio-allantoic membrane (CAM). OPN-deficient U87-MG cells gave rise to tumors that were significantly smaller than tumors formed from untransfected cells (paired t-test, p<0.05). Accordingly, the amount of proliferating cells in OPN-deficient tumors showed a six-fold reduction when compared to control tumors. However, OPN inhibition did not affect significantly tumor-associated angiogenesis. In vitro, OPN-silenced U87-MG and U373-MG cells showed decreased motility and migration. This is the first demonstration that OPN inhibition blocks glioma tumor growth, making this invasion-related protein an attractive target for glioma therapy. (c) 2009 UICC. [less ▲]Detailed reference viewed: 60 (11 ULg)
Proteomic analysis of human pancreas cancers for the identification of targetable biomarkers
Castronovo, Vincenzo ; ; et al
(2010)Detailed reference viewed: 55 (3 ULg)
Versican overexpression in human breast cancer lesions: Known and new isoforms for stromal tumor targeting.
Kischel, Philippe ; Waltregny, David ; Dumont, Bruno et al
in International Journal of Cancer = Journal International du Cancer (2010), 126(3), 640-50
Proteoglycans play a key role in cancer development and progression by participating in the constitution of a specific fertile tumor microenvironment. As they are largely overexpressed in the malignant ... [more ▼]
Proteoglycans play a key role in cancer development and progression by participating in the constitution of a specific fertile tumor microenvironment. As they are largely overexpressed in the malignant stroma, proteoglycans provide a reservoir of potential new targets for anticancer therapies, because they can serve to convey toxic payloads in the close proximity of cancer cells and subsequently destroy them. In this context, versican, a proteoglycan largely overexpressed in several solid cancers, bears the potential to be such an ideal target. As 4 main versican isoforms have been characterized, we sought to determine which isoform could represent the best target in human breast cancer. We used a series of 10 primary breast cancer lesions that were characterized as overexpressing the versican protein, when compared with matched normal breast tissues, using shotgun mass spectrometry and immunohistochemistry experiments. Quantitative polymerase chain reaction and western-blotting experiments were used to evaluate versican isoform expression in breast cancer/normal tissue pairs for which ARN quality was excellent. All known isoforms were significantly overexpressed in the malignant lesions, both at the mRNA and at the protein levels. In the course of this study, we also identified and cloned a new alternatively spliced versican isoform, referred to as V4, which was also found to be upregulated in human breast cancer. This study provides for the first time a comprehensive mRNA and protein analysis of versican isoforms expression in human breast tissues, and offers insights into which therapeutic strategy would be best suited to target versican in human breast cancer lesions. [less ▲]Detailed reference viewed: 158 (51 ULg)
Le ciblage therapeutique: vers une guerre propre et efficace contre le cancer
Castronovo, Vincenzo ; Waltregny, David ; Detry, Olivier et al
Scientific conference (2009, October)Detailed reference viewed: 135 (17 ULg)
Le ciblage thérapeutique : vers une guerre propre et efficace contre le cancer
Castronovo, Vincenzo ; Waltregny, David ; Detry, Olivier et al
in Revue Médicale de Liège (2009), 64
One promising avenue towards the development of more selective, better anticancer drugs consists in the targeted delivery of bioactive compounds to the tumor environment by means of binding molecules ... [more ▼]
One promising avenue towards the development of more selective, better anticancer drugs consists in the targeted delivery of bioactive compounds to the tumor environment by means of binding molecules specific for tumor-associated biomarkers. Eligibility of such markers for therapeutic use implies ideally three criteria : (i) accessibility from the bloodstream, (ii) expression at sufficient level and (iii) no (or much lower) expression in normal tissues. Most current discovery strategies (such as biomarker searching into body fluids) provide no clue as to whether proteins of interest are accessible, in human tissues, to suitable high-affinity ligands, such as systemically delivered monoclonal antibodies. Innovative proteomic technologies are able to identify such accessible biomarkers and represent a key step in the clinical development of such target therapies. [less ▲]Detailed reference viewed: 156 (35 ULg)
Faciogenital dysplasia protein Fgd1 regulates invadopodia biogenesis and extracellular matrix degradation and is up-regulated in prostate and breast cancer.
; ; et al
in Cancer Research (2009), 69(3), 747-52
Invadopodia are proteolytically active membrane protrusions that extend from the ventral surface of invasive tumoral cells grown on an extracellular matrix (ECM). The core machinery controlling ... [more ▼]
Invadopodia are proteolytically active membrane protrusions that extend from the ventral surface of invasive tumoral cells grown on an extracellular matrix (ECM). The core machinery controlling invadopodia biogenesis is regulated by the Rho GTPase Cdc42. To understand the upstream events regulating invadopodia biogenesis, we investigated the role of Fgd1, a Cdc42-specific guanine nucleotide exchange factor. Loss of Fgd1 causes the rare inherited human developmental disease faciogenital dysplasia. Here, we show that Fgd1 is required for invadopodia biogenesis and ECM degradation in an invasive cell model and functions by modulation of Cdc42 activation. We also find that Fgd1 is expressed in human prostate and breast cancer as opposed to normal tissue and that expression levels matched tumor aggressiveness. Our findings suggest a central role for Fgd1 in the focal degradation of the ECM in vitro and, for the first time, show a connection between Fgd1 and cancer progression, proposing that it might function during tumorigenesis. [less ▲]Detailed reference viewed: 73 (1 ULg)
HDAC4 represses p21(WAF1/Cip1) expression in human cancer cells through a Sp1-dependent, p53-independent mechanism.
Mottet, Denis ; Pirotte, Sophie ; Lamour, Virginie et al
in Oncogene (2009), 28(2), 243-56
Cancer cells have complex, unique characteristics that distinguish them from normal cells, such as increased growth rates and evasion of anti-proliferative signals. Global inhibition of class I and II ... [more ▼]
Cancer cells have complex, unique characteristics that distinguish them from normal cells, such as increased growth rates and evasion of anti-proliferative signals. Global inhibition of class I and II histone deacetylases (HDACs) stops cancer cell proliferation in vitro and has proven effective against cancer in clinical trials, at least in part, through transcriptional reactivation of the p21(WAF1/Cip1)gene. The HDACs that regulate p21(WAF1/Cip1) are not fully identified. Using small interfering RNAs, we found that HDAC4 participates in the repression of p21(WAF1/Cip1) through Sp1/Sp3-, but not p53-binding sites. HDAC4 interacts with Sp1, binds and reduces histone H3 acetylation at the Sp1/Sp3 binding site-rich p21(WAF1/Cip1) proximal promoter, suggesting a key role for Sp1 in HDAC4-mediated repression of p21(WAF1/Cip1). Induction of p21(WAF1/Cip1) mediated by silencing of HDAC4 arrested cancer cell growth in vitro and inhibited tumor growth in an in vivo human glioblastoma model. Thus, HDAC4 could be a useful target for new anti-cancer therapies based on selective inhibition of specific HDACs. [less ▲]Detailed reference viewed: 101 (22 ULg)
Small Integrin-Binding Ligand N-Linked Glycoproteins (Siblings): Multifunctional Proteins in Cancer
Bellahcene, Akeila ; Castronovo, Vincenzo ; et al
in Nature Reviews. Cancer (2008), 8(3), 212-26
Numerous components and pathways are involved in the complex interplay between cancer cells and their environment. The family of glycophosphoproteins comprising osteopontin, bone sialoprotein, dentin ... [more ▼]
Numerous components and pathways are involved in the complex interplay between cancer cells and their environment. The family of glycophosphoproteins comprising osteopontin, bone sialoprotein, dentin matrix protein 1, dentin sialophosphoprotein and matrix extracellular phosphoglycoprotein - small integrin-binding ligand N-linked glycoproteins (SIBLINGs) - are emerging as important players in many stages of cancer progression. From their detection in various human cancers to the demonstration of their key functional roles during malignant transformation, invasion and metastasis, the SIBLINGs are proteins with potential as diagnostic and prognostic tools, as well as new therapeutic targets. [less ▲]Detailed reference viewed: 64 (6 ULg)
Phenotypic Characterization of Osteoblasts from the Sclerotic Zones of Osteoarthritic Subchondral Bone
Sanchez, Christelle ; Deberg, Michelle ; Bellahcene, Akeila et al
in Arthritis and Rheumatism (2008), 58(2), 442-55
OBJECTIVE: To determine the phenotype of osteoblasts from the sclerotic zones of human osteoarthritic (OA) subchondral bone. METHODS: Human osteoblasts were isolated from sclerotic or nonsclerotic areas ... [more ▼]
OBJECTIVE: To determine the phenotype of osteoblasts from the sclerotic zones of human osteoarthritic (OA) subchondral bone. METHODS: Human osteoblasts were isolated from sclerotic or nonsclerotic areas of subchondral bone and cultured for 14 days in monolayer. The expression of 14 genes was investigated by real-time reverse transcription-polymerase chain reaction. The activities of alkaline phosphatase (AP) and transglutaminases (TGases) were quantified by enzymatic assays. C-terminal type I procollagen propeptide (CPI), interleukin-1beta (IL-1beta), IL-6, IL-8, transforming growth factor beta1 (TGFbeta1), osteocalcin (OC), and osteopontin (OPN) were assayed in the culture medium by immunoassay. RESULTS: Gene expression levels of matrix metalloproteinase 13, COL1A1 and COL1A2, OPN, tissue-nonspecific AP, OC, vascular endothelial growth factor, ANKH, TGase 2, factor XIIIA, and dentin matrix protein 1 were significantly up-regulated in sclerotic osteoblasts compared with nonsclerotic osteoblasts. In contrast, parathyroid hormone receptor gene expression was depressed in sclerotic osteoblasts, but bone sialoprotein levels were unchanged. The activities of AP and TGases were increased in sclerotic osteoblasts, while matrix mineralization, revealed by alizarin red staining, was decreased. In parallel, protein synthesis of CPI, OC, OPN, IL-6, IL-8, and TGFbeta1 was significantly higher in sclerotic osteoblasts than in nonsclerotic osteoblasts, while IL-1beta production was similar in both groups. CONCLUSION: These findings contribute to a better understanding of the mechanisms involved in subchondral bone sclerosis and identify osteoblasts with an altered phenotype as a potential target for future OA therapies. [less ▲]Detailed reference viewed: 111 (23 ULg)
Creb-1 and Ap-1 Transcription Factors Jund and Fra-2 Regulate Bone Sialoprotein Gene Expression in Human Breast Cancer Cells
Detry, Cédric ; Lamour, Virginie ; Castronovo, Vincenzo et al
in BONE (2008), 42(2), 422-31
Bone sialoprotein (BSP) expression is detected in a variety of human osteotropic cancers. High expression of BSP in breast and prostate primary carcinomas is associated with progression and bone ... [more ▼]
Bone sialoprotein (BSP) expression is detected in a variety of human osteotropic cancers. High expression of BSP in breast and prostate primary carcinomas is associated with progression and bone metastases development. In this study, we examined the transcriptional regulation of BSP gene expression in MDA-MB-231 and MCF-7 human breast cancer cells compared with Saos-2 human osteoblast-like cells. BSP human promoter deletion analyses delineated a -56/-84 region, which comprises a cAMP response element (CRE) that was sufficient for maximal promoter activity in breast cancer cell lines. We found that the basic fibroblast growth factor response element (FRE) also located in the proximal promoter was a crucial regulator of human BSP promoter activity in Saos-2 but not in breast cancer cells. Promoter activity experiments in combination with DNA mobility shift assays demonstrated that BSP promoter activity is under the control of the CRE element, through CREB-1, JunD and Fra-2 binding, in MDA-MB-231, MCF-7 and in Saos-2 cells. Forskolin, a protein kinase A pathway activator, failed to enhance BSP transcriptional activity suggesting that CRE site behaves as a constitutive rather than an inducible element in these cell lines. Over-expression of JunD and Fra-2 increased BSP promoter activity and upregulated endogenous BSP protein expression in MCF-7 and Saos-2 cells while siRNA-mediated inhibition of both factors expression significantly reduced BSP protein level in MDA-MB-231. Collectively, these data provide with new transcriptional mechanisms, implicating CREB and AP-1 factors, that control BSP gene expression in breast cancer cells. [less ▲]Detailed reference viewed: 56 (5 ULg)
Les histones desacetylases : nouvelles cibles pour les therapies anti-cancereuses.
Mottet, Denis ; Castronovo, Vincenzo
in Medecine Sciences : M/S (2008), 24(8-9), 742-6
Circa twenty-five years ago, cancer research was dominated by the concept that the origin of cancer was genetic. Thousands of genetic alterations have indeed been identified involving more than hundred ... [more ▼]
Circa twenty-five years ago, cancer research was dominated by the concept that the origin of cancer was genetic. Thousands of genetic alterations have indeed been identified involving more than hundred different genes in cancer development. Today, the model has evolved: it has been demonstrated that malignancies can be initiated not only through genetic alterations but also through epigenetic deregulations. By altering the expression of gene involved in cell regulation, epigenetic alterations, such as histone acetylation, play a key role in the initiation and progression of neoplasm. It has been shown that an imbalance between the acelylated and deacetylated status of chromatin is significantly involved in the acquisition of a malignant phenotype. Thus, the modulation of the histone acetylation level by histone deacetylase (HDAC) inhibitors could lead to a genetic re-programmation in cancer cells that would favor apoptosis and prevent proliferation. The potential therapeutic value of several HDAC inhibitors for cancer patients has been evaluated in clinical assays with very promising outcome. Indeed, the first inhibitors available for patients has been recently approved for cancer patients tracing the way for a new class of promising anti-cancer therapy modalities. [less ▲]Detailed reference viewed: 77 (7 ULg)
Cell membrane proteomic analysis identifies proteins differentially expressed in osteotropic human breast cancer cells.
Kischel, Philippe ; ; Dumont, Bruno et al
in Neoplasia : An International Journal for Oncology Research (2008), 10(9), 1014-20
Metastatic breast cancer cells are characterized by their high propensity to colonize the skeleton and form bone metastases, causing major morbidity and mortality. Identifying key proteins involved in the ... [more ▼]
Metastatic breast cancer cells are characterized by their high propensity to colonize the skeleton and form bone metastases, causing major morbidity and mortality. Identifying key proteins involved in the osteotropic phenotype would represent a major step toward the development of both new prognostic markers and new effective therapies. Cell surface proteins differentially expressed in cancer cells are preferred potential targets for antibody-based targeted therapies. In this study, using cell surface biotinylation and a mass spectrometric approach, we have compared the profile of accessible cell surface proteins between the human breast cancer cell line MDA-MB-231 and its highly osteotropic B02 subclone. This strategy allowed the identification of several proteins either up- or downregulated in the osteotropic cell line, and differential protein expressions were validated using antibody-based techniques. Class I HLAs were down-regulated in the bone metastatic variant, whereas alpha(v)beta(3) integrins, among others, were consistently up-regulated in this latter cell line. These results show that comprehensive profiling of the cell surface proteome of mother cancerous cell lines and derived organ-specific metastatic cell lines provides an effective approach for the identification of potential accessible marker proteins for both prognosis and antibody-based targeted therapies. [less ▲]Detailed reference viewed: 65 (9 ULg)