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Larry W. Fisher - One of the best experts on this subject based on the ideXlab platform.
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Bone Sialoprotein is localized to the root surface during cementogenesis
Journal of Bone and Mineral Research, 2009Co-Authors: R L Macneil, Catherine Strayhorn, N Sheng, Larry W. Fisher, Martha J. SomermanAbstract:: Bone Sialoprotein (BSP), an RGD-containing protein with cell attachment properties, is believed to play a regulatory role in the biomineralization of various connective tissues. To determine its possible role in tooth root formation, murine dentoalveolar tissues at sequential phases of development were analyzed immunohistochemically for the presence of BSP. BSP was localized to alveolar Bone and cementum at time points associated with initial mineralization of these tissues. In addition, northern blot analyses of dental follicle tissue at day 27 of tooth development indicated that BSP mRNA is expressed by dental follicle cells at a time point coincident with the initiation of cementogenesis on the peripheral tooth root surface. Collectively, these findings indicate that BSP may play an important role in the formation and mineralization of cementum.
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Bone Sialoprotein matrix metalloproteinase 2 and αvβ3 integrin in osteotropic cancer cell invasion
Journal of the National Cancer Institute, 2004Co-Authors: Abdullah Karadag, Neal S. Fedarko, Kalu U E Ogbureke, Larry W. FisherAbstract:Background: Bone Sialoprotein (BSP) interacts separately with both matrix metalloproteinase 2 (MMP-2) and integrin v3 and is overexpressed in many metastatic tumors. Its role in tumor biology, however, remains unclear. We investigated whether BSP enhances cancer cell invasiveness by forming a trimolecular complex with MMP-2 and cell-surface integrin v3. Methods: Invasiveness of breast, prostate, lung, and thyroid tumor cell lines was measured with a modified Boyden chamber assay. Binding and co-localization of BSP, MMP-2, and integrin v3 were investigated with immunoprecipitation and in situ hybridization. All statistical tests were two-sided. Results: Treatment with BSP increased invasiveness of many breast, prostate, lung, and thyroid cancer cells through Matrigel in a dose-dependent manner. BSP at 50 nM increased the invasiveness of SW-579 thyroid cancer cells (95.2 units, 95% confidence interval [CI] 90.4 to 100 units) by approximately 10-fold compared with that of untreated control SW-579 cells (9.1 units, 95% CI 5.7 to 12.5 units) (P<.001). Addition of an inactive mutated BSP, in which BSP’ s integrin-binding RGD tripeptide was altered, or addition of integrin v3-blocking antibodies resulted in invasiveness equivalent to that of untreated cells. Inhibiting cellular MMP-2 activity with chemical inhibitors or a specific antibody also blocked BSPenhanced invasiveness. Osteopontin and dentin matrix protein 1, proteins related to BSP that also bind integrin v3 and form complexes with other MMPs (but not MMP-2), did not enhance invasiveness. Immunoprecipitation showed that a complex containing BSP, integrin v3, and MMP-2 formed in vitro. Addition of BSP increased the amount of MMP-2 bound by cells in an integrindependent fashion. Co-expression of BSP, integrin v3, and MMP-2 in papillary thyroid carcinoma cells was shown by in situ hybridization. Conclusion: Cancer cells appear to become more invasive when BSP forms a cellsurface trimolecular complex by linking MMP-2 to integrin v3. [J Natl Cancer Inst 2004;96:956 ‐65]
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coexpression of Bone Sialoprotein bsp and the pivotal transcriptional regulator of osteogenesis cbfa1 runx2 in malignant melanoma
Calcified Tissue International, 2003Co-Authors: Mara Riminucci, Larry W. Fisher, Alessandro Corsi, Ketty Peris, Sergio Chimenti, Paolo BiancoAbstract:Bone Sialoprotein (BSP) is a member of the SIBLINGS family, normally restricted to the skeleton, but it has been shown to be ectopically expressed in some human invasive carcinomas. BSP expression in human cancer was initially associated with the ability of BSP-expressing tumors to metastasize to Bone, although the mechanism whereby BSP expression should facilitate homing of cancer cells to the Bone marrow environment has remained unexplained. More recently, clinical and experimental data have converged in highlighting a potential link between BSP expression and tumor invasiveness in general. We show here that human malignant melanoma cells express BSP in vivo as a function of extent of local invasion, and that expression of BSP mRNA and protein in melanoma cells is associated with the expression of the transcriptional regulator of osteogenic cell differentiation, Cbfa1/Runx2. It has been well established that expression of Cbfa1/Runx2 in the mouse is normally restricted to Bone-forming cells. In the mouse, Cbfa1/Runx2 dictates osteogenic differentiation of mesodermal cells by regulating Bone-specific genes. Since it also regulates expression of at least two matrix metalloproteases implicated in tumor invasion and metastasis (collagenase 3, membrane type 1 matrix metalloproteinase), we propose that the relationship between BSP expression and an invasive behavior in human epithelial cancer cells may be rooted in a common transcriptional control exerted by Cbfa1.
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elevated serum Bone Sialoprotein and osteopontin in colon breast prostate and lung cancer
Clinical Cancer Research, 2001Co-Authors: Neal S. Fedarko, Alka Jain, Abdullah Karadag, Matthew R Van Eman, Larry W. FisherAbstract:Purpose: Histological studies have shown that the two Sialoproteins, Bone Sialoprotein (BSP) and osteopontin (OPN), are induced in multiple types of cancer. We have recently found that these proteins are bound in serum to complement factor H and that the complex must be disrupted to generate free protein to measure their total levels. We hypothesized that measuring total BSP and OPN levels would provide informative markers for the detection of cancer. Experimental Design: As a proof of concept study, serum from patients with diagnosed breast, colon, lung, or prostate cancer (n = 20 for each type) as well as normal serum (n = 77) were analyzed using competitive ELISAs developed for BSP and OPN. Sensitivity, specificity, as well as positive and negative predictive values were determined for each Sialoprotein and cancer type. The relationship between sensitivity and specificity was profiled by receiver operating characteristic curves. Results and Conclusions: Determined values for serum BSP in ng/ml were 285 ± 19 for prostate, 373 ± 19 for colon, 318 ± 18 for breast, 155 ± 11 for lung cancer sera, and 154 ± 13 for normal sera. Values of OPN in ng/ml were 653 ± 39 for prostate, 449 ± 22 for colon, 814 ± 53 for breast, 724 ± 33 for lung, and 439 ± 30 for normal sera. The assays provide a high degree of sensitivity and specificity that enables the detection of colon, breast, prostate, and lung cancer.
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Flexible structures of SIBLING proteins, Bone Sialoprotein, and osteopontin.
Biochemical and biophysical research communications, 2001Co-Authors: Larry W. Fisher, Dennis A. Torchia, Berthold Fohr, M F Young, Neal S. FedarkoAbstract:Bone Sialoprotein (BSP) and osteopontin (OPN) are two members of the SIBLING (Small Integrin-Binding LIgand, N-linked Glycoprotein) family of genetically related proteins that are clustered on human chromosome 4. We present evidence that this entire family is the result of duplication and subsequent divergent evolution of a single ancient gene. The solution structures of these two post-translationally modified recombinant proteins were solved by one dimensional proton NMR and transverse relaxation times. The polypeptide backBones of both free BSP and OPN rapidly sample an ensemble of conformations consistent with them both being completely unstructured in solution. This flexibility appears to enable these relatively small glycoproteins to rapidly associate with a number of different binding partners including other proteins as well as the mineral phase of Bones and teeth. These proteins often function by bridging two proteins of fixed structures into a biologically active complex.
Jaro Sodek - One of the best experts on this subject based on the ideXlab platform.
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developmental expression of Bone Sialoprotein mrna in rat mineralized connective tissues
Journal of Bone and Mineral Research, 2009Co-Authors: Jinkun Chen, Howard S Shapiro, Jaro SodekAbstract:Bone Sialoprotein (BSP) is a phosphorylated and sulfated glycoprotein that is a major noncollagenous protein of Bone and other mineralizing connective tissues. BSP is characterized by the presence of several polyglutamic acid segments and an RGD motif that mediates cell attachment through a vitronectin-like receptor. Although the precise function of BSP is unknown, the expression of BSP in conjunction with Bone formation in vitro indicates a role for this protein in the biomineralization of connective tissues. In this study we used Northern hybridization and in situ hybridization to determine the tissue-specific and developmental expression of BSP during embryogenesis and growth of rat tissues. Analysis of tissues obtained from 13, 17, and 21 day fetuses, and from 4-, 14-, and 100-day-old animals indicates that BSP mRNA expression is restricted to cells actively forming the mineralizing tissues of Bone, dentin and cementum. BSP mRNA transcripts were first evident in fully differentiated osteoblasts of 17 day fetal tissues at sites of de novo intramembranous and endochondral Bone formation, with maximal expression observed at 21 days of gestation. Thereafter, BSP mRNA levels decreased markedly, and in adult Bone hybridization was detected only in the primary spongiosa of long Bones. In comparison, mRNAs for osteopontin (OPN), alkaline phosphatase (ALP), and osteocalcin (OC) peaked at 4-14 days postpartum before declining. In the tibiae, Northern hybridization revealed a second peak of mRNA for BSP, ALP, and OPN at 14 days, reflecting an increased osteogenic activity due to the formation of the secondary centers of ossification in the epiphyseal cartilage. In situ hybridization also revealed BSP mRNA in hypertrophic chondrocytes at sites of Bone formation, in odontoblasts of the incisor during dentinogenesis, and in cementoblasts during cementogenesis. In view of the restricted distribution and temporal changes in the expression of BSP mRNA that we observed together with the chemical properties of BSP, we believe that this protein has a specific role in mediating the initial stages of connective tissue mineralization.
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expression of rat Bone Sialoprotein promoter in transgenic mice
Journal of Bone and Mineral Research, 2009Co-Authors: Jinkun Chen, Huw F Thomas, Hangqing Jin, Heping Jiang, Jaro SodekAbstract:Bone Sialoprotein (BSP) is a major protein of the mineralized Bone extracellular matrix that has been implicated in the nucleation of hydroxyapatite crystals. Our previous studies have demonstrated that BSP mRNA is expressed by differentiated osteoblasts, odontoblasts, and cementoblasts involved in de novo mineralized tissue formation in a tissue-specific and developmentally regulated manner. To determine the basis of the selective expression of the BSP gene, we have generated four transgenic mouse lines in which ∼2.7 kb of the rat BSP promoter ligated to a luciferase reporter gene has been stably integrated into the mouse genome. Assays of luciferase activities in 5-day-old animals has revealed consistently high levels in Bone tissues with negligible activities in various other organs including kidney, liver, stomach, intestine, and spleen. In some animals, variable expression was observed in brain and skin. Temporal analyses revealed the highest luciferase expression in neonatal Bones, with expression decreasing markedly with subsequent growth and development, as observed previously for the endogenous gene in rats. Immunohistochemical analysis of luciferase activity and in situ hybridization of luciferase mRNA in Bone tissues show that differentiated osteoblasts express the highest levels of luciferase, consistent with the induction of endogenous gene expression. These studies demonstrate that the regulation of the BSP gene during osteoblastic differentiation, together with its tissue-specific, developmentally regulated expression, is primarily mediated within the ∼2.7 kb region of the promoter.
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fibroblast growth factor 2 and cyclic amp synergistically regulate Bone Sialoprotein gene expression
Bone, 2006Co-Authors: Emi Shimizu, Jaro Sodek, Hideki Takai, Youhei Nakayama, Yu Nakajima, Naoko Kato, Dongsoon Kim, Masato Arai, Ryoichiro Saito, Yorimasa OgataAbstract:Bone Sialoprotein (BSP) is a noncollagenous protein of the mineralized Bone extracellular matrix. We here report that FGF2 and cAMP act synergistically to stimulate BSP gene expression. Treatment of ROS 17/2.8 cells with either 10 ng/ml FGF2 or 1 microM FSK for 6 h resulted in 5.4- and 8.2-fold increases, respectively, in the levels of BSP mRNA. However, in the presence of both FGF2 and forskolin (FGF/FSK), BSP mRNA levels were increased synergistically by 20.4-fold. Using a luciferase reporter construct, encompassing BSP promoter nucleotides -116 to +60, transcription was also increased synergistically by 15.0-fold with FGF/FSK, compared to stimulations of 2.6- and 5.3-fold, respectively, for FGF2 and FSK alone. Transcriptional stimulation by FGF/FSK abrogated in constructs included 2 bp mutations in the inverted CCAAT, CRE, FRE and Pit-1 elements. Whereas the FRE-protein complex was increased by FGF2 and FGF/FSK, the Pit-1-protein complex was decreased by FSK and FGF/FSK. Notably, transcriptional activity induced by FGF/FSK was blocked by protein kinase A, tyrosine kinase and MEK inhibitors. These studies indicate that the combinatorial effects of FGF and FSK act through PKA, tyrosine kinase and MAP-kinase-dependent pathways, which target the inverted CCAAT, CRE, FRE and Pit-1 elements in the BSP gene to synergistically increase BSP expression.
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human osteocalcin and Bone Sialoprotein mediating osteomimicry of prostate cancer cells role of camp dependent protein kinase a signaling pathway
Cancer Research, 2005Co-Authors: Wenchin Huang, Jaro Sodek, Zhihui Xie, Hiroyuki Konaka, Haiyen E Zhau, Leland W K ChungAbstract:Osteocalcin and Bone Sialoprotein are the most abundant noncollagenous Bone matrix proteins expressed by osteoblasts. Surprisingly, osteocalcin and Bone Sialoprotein are also expressed by malignant but not normal prostate epithelial cells. The purpose of this study is to investigate how osteocalcin and Bone Sialoprotein expression is regulated in prostate cancer cells. Our investigation revealed that (a) human osteocalcin and Bone Sialoprotein promoter activities in an androgen-independent prostate cancer cell line of LNCaP lineage, C4-2B, were markedly enhanced 7- to 12-fold in a concentration-dependent manner by conditioned medium collected from prostate cancer and Bone stromal cells. (b) Deletion analysis of human osteocalcin and Bone Sialoprotein promoter regions identified cyclic AMP (cAMP)-responsive elements (CRE) as the critical determinants for conditioned medium-mediated osteocalcin and Bone Sialoprotein gene expression in prostate cancer cells. Consistent with these results, the protein kinase A (PKA) pathway activators forskolin and dibutyryl cAMP and the PKA pathway inhibitor H-89, respectively, increased or repressed human osteocalcin and Bone Sialoprotein promoter activities. (c) Electrophoretic mobility shift assay showed that conditioned medium-mediated stimulation of human osteocalcin and Bone Sialoprotein promoter activities occurs through increased interaction between CRE and CRE-binding protein. (d) Conditioned medium was found to induce human osteocalcin and Bone Sialoprotein promoter activities via increased CRE/CRE-binding protein interaction in a cell background-dependent manner, with marked stimulation in selected prostate cancer but not Bone stromal cells. Collectively, these results suggest that osteocalcin and Bone Sialoprotein expression is coordinated and regulated through cAMP-dependent PKA signaling, which may define the molecular basis of the osteomimicry exhibited by prostate cancer cells.
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delineation of the hydroxyapatite nucleating domains of Bone Sialoprotein
Journal of Biological Chemistry, 2003Co-Authors: Coralee E Tye, Jaro Sodek, Graeme K Hunter, Kevin J Warner, Kevin R Rattray, Jonathan A R Gordon, Harvey A. GoldbergAbstract:Bone Sialoprotein (BSP) is a highly modified, anionic phosphoprotein that is expressed almost exclusively in mineralizing connective tissues and has been shown to be a potent nucleator of hydroxyapatite (HA). Two polyglutamic acid (poly[E]) regions, predicted to be in an α-helical conformation and located in the amino-terminal half of the molecule, are believed to be responsible for this activity. Using a prokaryotic expression system, full-length rat BSP was expressed and tested for HA nucleating activity in a steady-state agarose gel system. The unmodified protein is less potent than native Bone BSP, indicating a role for the post-translational modifications in HA nucleation. Site-directed mutagenesis of the poly[E] regions in full-length BSP was performed, replacing the poly[E] with either polyaspartic acid (poly[D]) or polyalanine (poly[A]) to examine role of charge and conformation, respectively, in HA nucleation. Replacement of single domains with either poly[A] or poly[D] did not alter nucleating activity nor did replacement of both domains with poly[D]. Replacement of both domains with poly[A], however, significantly decreased nucleating activity. In addition, two recombinant peptides, each encompassing one of the two poly[E] domains, were expressed and tested for nucleating activity. Whereas the peptide encompassing the second poly[E] domain was capable of nucleating HA, the first domain peptide showed no activity. The conformation of the wild-type and mutated proteins and peptides were studied by circular dichroism and small angle x-ray scattering, and no secondary structure was evident. These results demonstrate that a sequence of at least eight contiguous glutamic acid residues is required for the nucleation of HA by BSP and that this nucleating "site" is not α-helical in conformation.
Akeila Bellahcene - One of the best experts on this subject based on the ideXlab platform.
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Bone Sialoprotein expression in primary human breast cancer is associated with Bone metastases development
Journal of Bone and Mineral Research, 2009Co-Authors: Akeila Bellahcene, Marie Kroll, Fabienne Liebens, Vincent CastronovoAbstract:Breast cancer metastasizes to Bone more frequently than to any other organ, and over 80% of advanced breast cancer patients develop Bone metastases. Our recent demonstration that human breast cancer cells express Bone Sialoprotein (BSP), a Bone matrix protein, provides a possible clue for the selective affinity of breast cancer cells for Bone. We tested the hypothesis that detection of BSP in primary human breast cancer could be a potential indicator of the ability of breast cancer cells to metastasize to Bone. BSP expression was evaluated in the primary breast cancers of 39 patients using immunoperoxidase and two specific anti-BSP antibodies. None of these patients presented clinically or scintigraphically detectable Bone metastases at the time of surgery. In the course of their disease, 22 patients developed clinically diagnosed Bone metastases. Expression of BSP in breast cancer cells from patients who developed Bone metastases was significantly higher (p = 0.008, according to the Mann-Whitney test) than in patients with no Bone involvement. No association was found between BSP expression in the primary breast lesions and axillary lymph node metastases. BSP expression was significantly increased in infiltrating ductal carcinoma compared with infiltrating lobular carcinoma (p = 0.0023). No correlation was found between immunoreactivity to BSP antibodies and estrogen receptor (ER) status, progesterone receptor (PR) status, or age. Our data suggest that BSP could help to identify which women will develop Bone metastases and provide new bases for the understanding of the molecular mechanism(s) responsible for breast cancer cells osteotropism.
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Bone Sialoprotein mediates human endothelial cell attachment and migration and promotes angiogenesis
Circulation Research, 2000Co-Authors: Akeila Bellahcene, Larry W. Fisher, Berthold Fohr, Neal S. Fedarko, Marian F Young, Karine Bonjean, Frank A Robey, Vincent CastronovoAbstract:Abstract—Bone Sialoprotein (BSP) is a secreted glycoprotein primarily found in sites of biomineralization. Recently, we demonstrated that BSP is strongly upregulated in osteotropic cancers and particularly those that exhibit microcalcifications. BSP contains an Arg-Gly-Asp (RGD) motif found in other adhesive molecules that interact with cellular integrins. In Bone, BSP has been shown to mediate the attachment of osteoblasts and osteoclasts via αvβ3 integrin receptors. Ligands for αvβ3 integrin are considered to play a central role during angiogenesis. Therefore, we used human umbilical vein endothelial cells (HUVECs) to study the potential role of BSP in angiogenesis. We found that purified eukaryotic recombinant human BSP (rhBSP) is able to promote both adhesion and chemotactic migration of HUVECs in a dose-dependent manner. These interactions involve HUVEC αvβ3 integrin receptors and the RGD domain of BSP. Indeed, HUVECs attach to a recombinant BSP fragment containing the RGD domain, whereas this respon...
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prognostic value of Bone Sialoprotein expression in clinically localized human prostate cancer
Journal of the National Cancer Institute, 1998Co-Authors: David Waltregny, Larry W. Fisher, M F Young, Akeila Bellahcene, Vincent Castronovo, Walthere Dewe, Jean De Leval, Ivan Van Riet, Pedro L FernandezAbstract:Background: Bone Sialoprotein (BSP), a Bone matrix protein, was recently found to be expressed ectopically in breast cancer and to have a statistically significant association with poor prognosis and the development of Bone metastases in that disease. These data prompted us to investigate whether BSP might also be expressed in human prostate cancer, which often metastasizes to Bone, and be predictive for progression risk. Methods: Tissue sections from 180 patients who had undergone a radical prostatectomy for localized prostate cancer were analyzed immunohistochemically for BSP expression. Biochemical progression was defined as an increasing serum prostate-specific antigen level of 0.5 ng/mL or more. Statistical analysis was used to assess associations between pathologic findings and level of BSP expression, and a Cox proportional hazards model was used to determine which clinical and histologic parameters, including stage, Gleason score, and BSP expression (immunostaining intensity and extent), were independently associated with biochemical progression. All P values were two-sided. Results: Most of the prostate cancer lesions examined (78.9%) expressed detectable levels of BSP, compared with no or low expression in the adjacent normal glandular tissue. A statistically significant association was found between BSP expression and biochemical progression in both univariate and multivariate analyses. After a follow-up interval of 3 years, the biochemical relapse rate was 36.7% (95% confidence interval [CI] = 23.4%-47.7%) in patients whose tumors expressed high levels of BSP compared with 12.1% (95% CI = 2.3%-20.8%) in patients whose tumors expressed no or a low detectable level of the protein (logrank test, P = .0014). BSP expression status could identify those patients at higher risk of biochemical progression (logrank test, P<.05) among patients with moderately differentiated tumors or with pathologically confined tumors. Conclusions: To our knowledge, this study is the first to demonstrate BSP expression in human prostate cancer and to highlight the protein's statistically significant prognostic value in patients with clinically confined prostate adenocarcinomas.
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expression of Bone Sialoprotein in human lung cancer
Calcified Tissue International, 1997Co-Authors: Akeila Bellahcene, Larry W. Fisher, Sylvie Menard, Naima Maloujahmoum, H Pastorino, Elda Tagliabue, Vincenzo CastronovoAbstract:Lung cancer belongs to the group of malignant lesions that specifically select Bone as secondary implantation site. The molecular bases for this property, defined as osteotropism, is still largely unknown. The recent demonstration that human breast cancer cells express and attach to Bone Sialoprotein (BSP), a sulfated phosphoprotein rich in Bone and other mineralized tissues, could provide a clue to elucidating Bone metastases formation. BSP contains the integrin binding peptide Arg-Gly-Asp (RGD), as well as non-RGD cell attachment domain. Using an immunoperoxidase technique and a specific polyclonal antibody directed against a BSP synthetic peptide, we examined the expression of BSP in 48 lung lesions including 25 squamous carcinoma, 21 adenocarcinoma, and 2 bronchioloalveolar cancers, as well as 38 human ovarian carcinoma that constitute a group of generally nonosteotropic cancers. BSP was not specifically detected in normal lung tissue with the exception of cartilage associated with bronchi. Most of the adenocarcinoma (74%) and all squamous carcinoma of the lung examined exhibited detectable levels of BSP. Staining was mainly cytoplasmic and membrane associated. The two bronchioloalveolar lung cancers examined did not show detectable amounts of BSP. When microcalcifications were observed in pulmonary malignant lesions, they were usually associated with cancer cells expressing BSP. Only 21% of the ovarian cancers examined contained malignant cells with 2+ or 3+ positivity for BSP. We further demonstrated that in 8 of 10 additional lung cancers, BSP was detected at the mRNA level. Our observation is the first demonstration that BSP is expressed in non-small cell lung carcinoma. Lung cancer cells are now the second type of osteotropic malignant cells described to express BSP. Added to the observation that BSP expression is not frequent in ovarian carcinoma, a low osteotropic cancer, our study supports our hypothesis that BSP could play a role in determining the affinity of cancer cells to Bone.
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expression of Bone Sialoprotein in primary human breast cancer is associated with poor survival
International Journal of Cancer, 1996Co-Authors: Akeila Bellahcene, Sylvie Menard, Rosaria Bufalino, Louis Moreau, Vincent CastronovoAbstract:We have recently demonstrated that Bone Sialoprotein (BSP), a Bone-matrix protein involved in hydroxyapatite crystal formation, is ectopically expressed in human breast cancers. We explored a possible association between expression of BSP in primary breast cancer and patients' survival. We analyzed BSP expression in 454 breast-cancer patients by immunohistochemistry on archival paraffin-embedded material using an anti-BSP polyclonal antibody. BSP expression was correlated to survival, tumor size, axillary lymph-node status and first site of distant metastasis. Of the breast cancers analyzed, 89% expressed detectable amounts of BSP. We found a statistical association between expression of BSP and poor prognosis as indicated by survival curves analyzed using the log rank and the Gehan methods. BSP expression was significantly higher in breast-cancer patients with axillary lymph-node involvement. Interestingly, survival of patients with positive lymph nodes but BSP-negative tumors was significantly higher than that of patients with no lymph-node involvement but BSP-positive cancers. The frequency of Bone metastases was higher in the group of patients with BSP-positive tumors (22%) than in the group with BSP-negative cancers (7%). There was a significant increase in the incidence of lung metastases in patients whose tumors were negative for BSP. Our data show that Bone Sialoprotein expression in breast cancer is associated with poor prognosis. BSP detection also appears to be a valuable marker with which to identify, among the lymph-node-negative patients, those who have high risk of disease progression.
Neal S. Fedarko - One of the best experts on this subject based on the ideXlab platform.
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Bone Sialoprotein matrix metalloproteinase 2 and αvβ3 integrin in osteotropic cancer cell invasion
Journal of the National Cancer Institute, 2004Co-Authors: Abdullah Karadag, Neal S. Fedarko, Kalu U E Ogbureke, Larry W. FisherAbstract:Background: Bone Sialoprotein (BSP) interacts separately with both matrix metalloproteinase 2 (MMP-2) and integrin v3 and is overexpressed in many metastatic tumors. Its role in tumor biology, however, remains unclear. We investigated whether BSP enhances cancer cell invasiveness by forming a trimolecular complex with MMP-2 and cell-surface integrin v3. Methods: Invasiveness of breast, prostate, lung, and thyroid tumor cell lines was measured with a modified Boyden chamber assay. Binding and co-localization of BSP, MMP-2, and integrin v3 were investigated with immunoprecipitation and in situ hybridization. All statistical tests were two-sided. Results: Treatment with BSP increased invasiveness of many breast, prostate, lung, and thyroid cancer cells through Matrigel in a dose-dependent manner. BSP at 50 nM increased the invasiveness of SW-579 thyroid cancer cells (95.2 units, 95% confidence interval [CI] 90.4 to 100 units) by approximately 10-fold compared with that of untreated control SW-579 cells (9.1 units, 95% CI 5.7 to 12.5 units) (P<.001). Addition of an inactive mutated BSP, in which BSP’ s integrin-binding RGD tripeptide was altered, or addition of integrin v3-blocking antibodies resulted in invasiveness equivalent to that of untreated cells. Inhibiting cellular MMP-2 activity with chemical inhibitors or a specific antibody also blocked BSPenhanced invasiveness. Osteopontin and dentin matrix protein 1, proteins related to BSP that also bind integrin v3 and form complexes with other MMPs (but not MMP-2), did not enhance invasiveness. Immunoprecipitation showed that a complex containing BSP, integrin v3, and MMP-2 formed in vitro. Addition of BSP increased the amount of MMP-2 bound by cells in an integrindependent fashion. Co-expression of BSP, integrin v3, and MMP-2 in papillary thyroid carcinoma cells was shown by in situ hybridization. Conclusion: Cancer cells appear to become more invasive when BSP forms a cellsurface trimolecular complex by linking MMP-2 to integrin v3. [J Natl Cancer Inst 2004;96:956 ‐65]
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elevated serum Bone Sialoprotein and osteopontin in colon breast prostate and lung cancer
Clinical Cancer Research, 2001Co-Authors: Neal S. Fedarko, Alka Jain, Abdullah Karadag, Matthew R Van Eman, Larry W. FisherAbstract:Purpose: Histological studies have shown that the two Sialoproteins, Bone Sialoprotein (BSP) and osteopontin (OPN), are induced in multiple types of cancer. We have recently found that these proteins are bound in serum to complement factor H and that the complex must be disrupted to generate free protein to measure their total levels. We hypothesized that measuring total BSP and OPN levels would provide informative markers for the detection of cancer. Experimental Design: As a proof of concept study, serum from patients with diagnosed breast, colon, lung, or prostate cancer (n = 20 for each type) as well as normal serum (n = 77) were analyzed using competitive ELISAs developed for BSP and OPN. Sensitivity, specificity, as well as positive and negative predictive values were determined for each Sialoprotein and cancer type. The relationship between sensitivity and specificity was profiled by receiver operating characteristic curves. Results and Conclusions: Determined values for serum BSP in ng/ml were 285 ± 19 for prostate, 373 ± 19 for colon, 318 ± 18 for breast, 155 ± 11 for lung cancer sera, and 154 ± 13 for normal sera. Values of OPN in ng/ml were 653 ± 39 for prostate, 449 ± 22 for colon, 814 ± 53 for breast, 724 ± 33 for lung, and 439 ± 30 for normal sera. The assays provide a high degree of sensitivity and specificity that enables the detection of colon, breast, prostate, and lung cancer.
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Flexible structures of SIBLING proteins, Bone Sialoprotein, and osteopontin.
Biochemical and biophysical research communications, 2001Co-Authors: Larry W. Fisher, Dennis A. Torchia, Berthold Fohr, M F Young, Neal S. FedarkoAbstract:Bone Sialoprotein (BSP) and osteopontin (OPN) are two members of the SIBLING (Small Integrin-Binding LIgand, N-linked Glycoprotein) family of genetically related proteins that are clustered on human chromosome 4. We present evidence that this entire family is the result of duplication and subsequent divergent evolution of a single ancient gene. The solution structures of these two post-translationally modified recombinant proteins were solved by one dimensional proton NMR and transverse relaxation times. The polypeptide backBones of both free BSP and OPN rapidly sample an ensemble of conformations consistent with them both being completely unstructured in solution. This flexibility appears to enable these relatively small glycoproteins to rapidly associate with a number of different binding partners including other proteins as well as the mineral phase of Bones and teeth. These proteins often function by bridging two proteins of fixed structures into a biologically active complex.
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factor h binding to Bone Sialoprotein and osteopontin enables tumor cell evasion of complement mediated attack
Journal of Biological Chemistry, 2000Co-Authors: Neal S. Fedarko, Pamela Gehron Robey, Berthold Fohr, Marian F Young, Larry W. FisherAbstract:Abstract Metastatic cancer cells, like trophoblasts of the developing placenta, are invasive and must escape immune surveillance to survive. Complement has long been thought to play a significant role in the tumor surveillance mechanism. Bone Sialoprotein (BSP) and osteopontin (OPN, ETA-1) are expressed by trophoblasts and are strongly up-regulated by many tumors. Indeed, BSP has been shown to be a positive indicator of the invasive potential of some tumors. In this report, we show that BSP and OPN form rapid and tight complexes with complement Factor H. Besides its key role in regulating complement-mediated cell lysis, Factor H also appears to play a role when “hijacked” by invading organisms in enabling cellular evasion of complement. We have investigated whether BSP and OPN may play a similar role in tumor cell complement evasion by testing to see whether these glycoproteins could promote tumor cell survival. Recombinant OPN and BSP can protect murine erythroleukemia cells from attack by human complement as well as human MCF-7 breast cancer cells and U-266 myeloma cells from attack by guinea pig complement. The mechanism of this gain of function by tumor cell expression of BSP or OPN has been defined using specific peptides and antibodies to block BSP and OPN protective activity. The expression of BSP and OPN in tumor cells provides a selective advantage for survival via initial binding to αVβ3 integrin (both) or CD44 (OPN) on the cell surface, followed by sequestration of Factor H to the cell surface and inhibition of complement-mediated cell lysis.
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Bone Sialoprotein mediates human endothelial cell attachment and migration and promotes angiogenesis
Circulation Research, 2000Co-Authors: Akeila Bellahcene, Larry W. Fisher, Berthold Fohr, Neal S. Fedarko, Marian F Young, Karine Bonjean, Frank A Robey, Vincent CastronovoAbstract:Abstract—Bone Sialoprotein (BSP) is a secreted glycoprotein primarily found in sites of biomineralization. Recently, we demonstrated that BSP is strongly upregulated in osteotropic cancers and particularly those that exhibit microcalcifications. BSP contains an Arg-Gly-Asp (RGD) motif found in other adhesive molecules that interact with cellular integrins. In Bone, BSP has been shown to mediate the attachment of osteoblasts and osteoclasts via αvβ3 integrin receptors. Ligands for αvβ3 integrin are considered to play a central role during angiogenesis. Therefore, we used human umbilical vein endothelial cells (HUVECs) to study the potential role of BSP in angiogenesis. We found that purified eukaryotic recombinant human BSP (rhBSP) is able to promote both adhesion and chemotactic migration of HUVECs in a dose-dependent manner. These interactions involve HUVEC αvβ3 integrin receptors and the RGD domain of BSP. Indeed, HUVECs attach to a recombinant BSP fragment containing the RGD domain, whereas this respon...
Vincent Castronovo - One of the best experts on this subject based on the ideXlab platform.
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Bone Sialoprotein expression in primary human breast cancer is associated with Bone metastases development
Journal of Bone and Mineral Research, 2009Co-Authors: Akeila Bellahcene, Marie Kroll, Fabienne Liebens, Vincent CastronovoAbstract:Breast cancer metastasizes to Bone more frequently than to any other organ, and over 80% of advanced breast cancer patients develop Bone metastases. Our recent demonstration that human breast cancer cells express Bone Sialoprotein (BSP), a Bone matrix protein, provides a possible clue for the selective affinity of breast cancer cells for Bone. We tested the hypothesis that detection of BSP in primary human breast cancer could be a potential indicator of the ability of breast cancer cells to metastasize to Bone. BSP expression was evaluated in the primary breast cancers of 39 patients using immunoperoxidase and two specific anti-BSP antibodies. None of these patients presented clinically or scintigraphically detectable Bone metastases at the time of surgery. In the course of their disease, 22 patients developed clinically diagnosed Bone metastases. Expression of BSP in breast cancer cells from patients who developed Bone metastases was significantly higher (p = 0.008, according to the Mann-Whitney test) than in patients with no Bone involvement. No association was found between BSP expression in the primary breast lesions and axillary lymph node metastases. BSP expression was significantly increased in infiltrating ductal carcinoma compared with infiltrating lobular carcinoma (p = 0.0023). No correlation was found between immunoreactivity to BSP antibodies and estrogen receptor (ER) status, progesterone receptor (PR) status, or age. Our data suggest that BSP could help to identify which women will develop Bone metastases and provide new bases for the understanding of the molecular mechanism(s) responsible for breast cancer cells osteotropism.
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Bone Sialoprotein mediates human endothelial cell attachment and migration and promotes angiogenesis
Circulation Research, 2000Co-Authors: Akeila Bellahcene, Larry W. Fisher, Berthold Fohr, Neal S. Fedarko, Marian F Young, Karine Bonjean, Frank A Robey, Vincent CastronovoAbstract:Abstract—Bone Sialoprotein (BSP) is a secreted glycoprotein primarily found in sites of biomineralization. Recently, we demonstrated that BSP is strongly upregulated in osteotropic cancers and particularly those that exhibit microcalcifications. BSP contains an Arg-Gly-Asp (RGD) motif found in other adhesive molecules that interact with cellular integrins. In Bone, BSP has been shown to mediate the attachment of osteoblasts and osteoclasts via αvβ3 integrin receptors. Ligands for αvβ3 integrin are considered to play a central role during angiogenesis. Therefore, we used human umbilical vein endothelial cells (HUVECs) to study the potential role of BSP in angiogenesis. We found that purified eukaryotic recombinant human BSP (rhBSP) is able to promote both adhesion and chemotactic migration of HUVECs in a dose-dependent manner. These interactions involve HUVEC αvβ3 integrin receptors and the RGD domain of BSP. Indeed, HUVECs attach to a recombinant BSP fragment containing the RGD domain, whereas this respon...
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prognostic value of Bone Sialoprotein expression in clinically localized human prostate cancer
Journal of the National Cancer Institute, 1998Co-Authors: David Waltregny, Larry W. Fisher, M F Young, Akeila Bellahcene, Vincent Castronovo, Walthere Dewe, Jean De Leval, Ivan Van Riet, Pedro L FernandezAbstract:Background: Bone Sialoprotein (BSP), a Bone matrix protein, was recently found to be expressed ectopically in breast cancer and to have a statistically significant association with poor prognosis and the development of Bone metastases in that disease. These data prompted us to investigate whether BSP might also be expressed in human prostate cancer, which often metastasizes to Bone, and be predictive for progression risk. Methods: Tissue sections from 180 patients who had undergone a radical prostatectomy for localized prostate cancer were analyzed immunohistochemically for BSP expression. Biochemical progression was defined as an increasing serum prostate-specific antigen level of 0.5 ng/mL or more. Statistical analysis was used to assess associations between pathologic findings and level of BSP expression, and a Cox proportional hazards model was used to determine which clinical and histologic parameters, including stage, Gleason score, and BSP expression (immunostaining intensity and extent), were independently associated with biochemical progression. All P values were two-sided. Results: Most of the prostate cancer lesions examined (78.9%) expressed detectable levels of BSP, compared with no or low expression in the adjacent normal glandular tissue. A statistically significant association was found between BSP expression and biochemical progression in both univariate and multivariate analyses. After a follow-up interval of 3 years, the biochemical relapse rate was 36.7% (95% confidence interval [CI] = 23.4%-47.7%) in patients whose tumors expressed high levels of BSP compared with 12.1% (95% CI = 2.3%-20.8%) in patients whose tumors expressed no or a low detectable level of the protein (logrank test, P = .0014). BSP expression status could identify those patients at higher risk of biochemical progression (logrank test, P<.05) among patients with moderately differentiated tumors or with pathologically confined tumors. Conclusions: To our knowledge, this study is the first to demonstrate BSP expression in human prostate cancer and to highlight the protein's statistically significant prognostic value in patients with clinically confined prostate adenocarcinomas.
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expression of Bone Sialoprotein in primary human breast cancer is associated with poor survival
International Journal of Cancer, 1996Co-Authors: Akeila Bellahcene, Sylvie Menard, Rosaria Bufalino, Louis Moreau, Vincent CastronovoAbstract:We have recently demonstrated that Bone Sialoprotein (BSP), a Bone-matrix protein involved in hydroxyapatite crystal formation, is ectopically expressed in human breast cancers. We explored a possible association between expression of BSP in primary breast cancer and patients' survival. We analyzed BSP expression in 454 breast-cancer patients by immunohistochemistry on archival paraffin-embedded material using an anti-BSP polyclonal antibody. BSP expression was correlated to survival, tumor size, axillary lymph-node status and first site of distant metastasis. Of the breast cancers analyzed, 89% expressed detectable amounts of BSP. We found a statistical association between expression of BSP and poor prognosis as indicated by survival curves analyzed using the log rank and the Gehan methods. BSP expression was significantly higher in breast-cancer patients with axillary lymph-node involvement. Interestingly, survival of patients with positive lymph nodes but BSP-negative tumors was significantly higher than that of patients with no lymph-node involvement but BSP-positive cancers. The frequency of Bone metastases was higher in the group of patients with BSP-positive tumors (22%) than in the group with BSP-negative cancers (7%). There was a significant increase in the incidence of lung metastases in patients whose tumors were negative for BSP. Our data show that Bone Sialoprotein expression in breast cancer is associated with poor prognosis. BSP detection also appears to be a valuable marker with which to identify, among the lymph-node-negative patients, those who have high risk of disease progression.