High Osteopontin Expression Research Articles

2145 MACROPHAGE-COLONY STIMULATING FACTOR–DEFICIENT MICE DEMONSTRATE THAT MACROPHAGES PLAY A DEFENSIVE ROLE AGAINST RENAL STONE FORMATION

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112145 MACROPHAGE-COLONY STIMULATING FACTOR–DEFICIENT MICE DEMONSTRATE THAT MACROPHAGES PLAY A DEFENSIVE ROLE AGAINST RENAL STONE FORMATION Kazumi Taguchi, Atsushi Okada, Yasuhiro Fujii, Kazuhiro Niimi, Takahiro Kobayashi, Shuzo Hamamoto, Masahito Hirose, Yasunori Itoh, Takahiro Yasui, Keiichi Tozawa, Shoichi Sasaki, Yutaro Hayashi, and Kenjiro Kohri Kazumi TaguchiKazumi Taguchi Nagoya, Japan More articles by this author , Atsushi OkadaAtsushi Okada Nagoya, Japan More articles by this author , Yasuhiro FujiiYasuhiro Fujii Nagoya, Japan More articles by this author , Kazuhiro NiimiKazuhiro Niimi Nagoya, Japan More articles by this author , Takahiro KobayashiTakahiro Kobayashi Nagoya, Japan More articles by this author , Shuzo HamamotoShuzo Hamamoto Nagoya, Japan More articles by this author , Masahito HiroseMasahito Hirose Nagoya, Japan More articles by this author , Yasunori ItohYasunori Itoh Nagoya, Japan More articles by this author , Takahiro YasuiTakahiro Yasui Nagoya, Japan More articles by this author , Keiichi TozawaKeiichi Tozawa Nagoya, Japan More articles by this author , Shoichi SasakiShoichi Sasaki Nagoya, Japan More articles by this author , Yutaro HayashiYutaro Hayashi Nagoya, Japan More articles by this author , and Kenjiro KohriKenjiro Kohri Nagoya, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2356AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We have recently reported in a microarray study that the levels of macrophage-related genes were elevated during renal stone formation. In addition, we have revealed an interesting phenomenon involving the spontaneous elimination of renal crystals. A high expression of macrophages was also observed in this phenomenon, which suggests that macrophages have a role in crystal aggregation. Here, we investigated the functions of renal macrophages in the development and elimination of calcium oxalate crystals by using macrophage-colony stimulating factor (M-CSF)–deficient mice. METHODS We used M-CSF–deficient mice, which have a mutation in the M-CSF gene. Eight-week-old male mice were divided into 4 groups: wild type (WT), homozygous (op/op), and WT and op/op injected with 3 × 104 units/body M-CSF (WT+CSF and op+CSF). The mice were administered with 100 mg/kg glyoxylate by daily intraabdominal injection, and the kidneys were extracted to examine stone formation, at designated time points (days 1, 3, 5, and 7). We performed F4/80 and M-CSF staining to evaluate the expression of macrophages. Both crystal and macrophage formations were evaluated with transmitted electron microscopy (TEM). The expression of osteopontin (OPN), F4/80, and lysozyme (Lyz) was examined by western blotting (WB) and quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS The number of renal stones in WT+CSF was markedly decreased compared to other groups. Crystal formation was detected in the cortical-medullary region in the WT and op+CSF groups, although crystals were detected in the papilla in the op/op group (Fig). WB and RT-PCR showed a high expression of OPN but a low expression of F4/80 and Lyz in op/op mice. Furthermore, TEM revealed crystals phagocytosed by macrophages in the cortical-medullary region, except in op/op mice. CONCLUSIONS Crystal formation was detected in the papilla region in M-CSF–deficient mice, which had never been observed in other mouse kidney stones. This study suggests that crystals attached to the renal papilla without elimination by macrophage phagocytosis in the cortical-medullary region in op/op mice. Macrophages play a major role in the defense against crystal attachment by elimination of crystals in the renal interstitial space. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e858-e859 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kazumi Taguchi Nagoya, Japan More articles by this author Atsushi Okada Nagoya, Japan More articles by this author Yasuhiro Fujii Nagoya, Japan More articles by this author Kazuhiro Niimi Nagoya, Japan More articles by this author Takahiro Kobayashi Nagoya, Japan More articles by this author Shuzo Hamamoto Nagoya, Japan More articles by this author Masahito Hirose Nagoya, Japan More articles by this author Yasunori Itoh Nagoya, Japan More articles by this author Takahiro Yasui Nagoya, Japan More articles by this author Keiichi Tozawa Nagoya, Japan More articles by this author Shoichi Sasaki Nagoya, Japan More articles by this author Yutaro Hayashi Nagoya, Japan More articles by this author Kenjiro Kohri Nagoya, Japan More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Combination of osteopontin and activated leukocyte cell adhesion molecule as potent prognostic discriminators in HER2- and ER-negative breast cancer

Background:To analyse the discriminative impact of osteopontin (OPN) and activated leukocyte cell adhesion molecule (ALCAM), combined with human epidermal growth factor 2 (HER2) and oestrogen receptor (ER) in breast cancer.Methods:Osteopontin, ALCAM, HER2 and ER mRNA expression in breast cancer tissues of 481 patients were analysed (mRNA microarray analysis, kinetic RT–PCR). Hierarchical clustering was performed in training cohort A (N=100, adjuvant treatment) and validation cohorts B (N=200, no adjuvant treatment, low-risk) and C (N=181, adjuvant treatment, high-risk).Results:Negative/low ER and HER2, high OPN and low ALCAM mRNA expression helped to identify patients at particularly high risk, showing shorter DFS, P<0.001, and OAS, P=0.001. Although both validation cohorts showed diverse risk and treatment profiles, this marker constellation was concordantly associated with shorter DFS and OAS (P<0.001 and P=0.075 for cohort B and P=0.043 and P<0.001 for cohort C, respectively). In multivariate analysis, this algorithm was the main independent prognostic factor. Cohort B: DFS, P=0.0065, OAS, not significant; cohort C: DFS, P=0.026, OAS, P<0.001.Conclusion:Activated leukocyte cell adhesion molecule and OPN mRNA expression has a strong discriminative impact on survival within cancer patients with low or negative expression of ER and HER2, so called ‘high-risk’ breast cancers, and might help in identifying patients who could benefit from new treatment approaches like targeted therapies in the adjuvant setting.

The implication of osteopontin ( OPN) expression and genetic polymorphisms of OPN promoter in oral carcinogenesis

Osteopontin (OPN) is an extracellular matrix protein in hard tissues. The polymorphism in promoter region of OPN gene correlates to different gene expression and might implicate potential roles in tumor progression and metastasis. Immunohistochemistry (IHC) was utilized to detect the OPN expression in 58 oral squamous cell carcinoma (OSCC) tissues and adjacent normal oral mucosa. The differential OPN expression was further analyzed in relation to clinico-pathological features. Genomic DNA was obtained from isolated leukocytes of blood samples of OSCC patients (n=100), and healthy individuals (n=97) from Taiwan. The OPN gene polymorphism was analyzed by direct sequencing. Our result showed OPN expression was significantly higher in OSCC tissues than in the paired adjacent normal tissues (p<0.01). The expression of OPN was significantly associated with nodal metastasis and the more advanced clinical stage (p<0.05). More prevalent -156 insGG/insGG genotype and -443 T/T genotype was found in OSCC patients (p<0.05). A significant difference in -443T/-156GG/-66T and -443C/-156G/-66T haplotypes between OSCC and controls (p<0.05) was also noted. The OPN expression in tumor tissues significantly correlated with -156 insGG/insGG and -156 G/G+insGG/G genotypes (p<0.05). The conclusion is tissue OPN expression correlates to OSCC progression. -156 insGG/insGG genotype is associated with OSCC susceptibility and higher OPN expression.

Osteopontin: A Biomarker to Predict the Outcome of Inflammatory Heart Disease

Inflammatory processes of the heart are often induced by viruses. Although most acute virus-induced myocarditis quickly resolves, some patients develop chronic myocarditis resulting in a considerable disruption of the myocardial matrix network, finally leading to cardiac dysfunction. The death of cardiomyocytes due to virus replication is followed by the attraction of macrophages and T cells to the sites of cardiac damage. Ongoing inflammation is usually suppressed by interleukin-10 and transforming growth factor-beta production, thus activating myofibroblasts and secretion of extracellular matrix proteins like collagen type I. Also, osteopontin (OPN), a matricellular protein with cytokine-like properties, is critically involved in inflammatory pathways and can modulate the cell biology of cardiac repair. In our model of coxsackievirus B3-induced myocarditis, we have shown that increased early OPN expression in macrophages is a determinant of fibrosis and enhanced cardiac remodeling. OPN was not found to influence the efficacy of the antiviral immune response. Also, in patients with acute and chronic myocarditis, but not in patients with end-stage dilated cardiomyopathy, we found a high OPN expression in macrophages, indicating active inflammatory processes. Thus cardiac OPN expression might be considered as a biomarker indicating ongoing cardiac inflammation preceding fibrosis and remodeling of the heart.

Osteopontin overexpression predicts poor prognosis of upper urinary tract urothelial carcinoma

Objectives Studies indicate overexpression of osteopontin (OPN) promotes carcinogenesis, progression and metastasis of multiple human malignancies. However, the function of OPN in urothelial carcinoma (UC) of the upper urinary tract has not been investigated. This study evaluates the clinical significance of OPN expression in upper urinary tract UC. Materials and methods One hundred and ten cases (median age = 64, range = 24–84 years) of renal pelvic or ureter UC were retrospectively reviewed in this study. OPN expression were evaluated by immunohistochemistry staining on paraffin-embedded section of the tumor and scored by two qualified pathologists. Results High OPN expression was found in 54 (49.1%) of the cancer specimens. OPN expression was not significantly correlated with tumor T stage ( P = 0.761), N stage ( P = 0.339) or grade ( P = 0.349). However, OPN expression was differently expressed by gender ( P = 0.012) and cancer location ( P = 0.026). OPN expression did not correlate with bladder recurrence-free ( P = 0.661) or extra-bladder recurrence-free ( P = 0.787) survival, but high OPN expression was a significant predictor for cancer-specific survival ( P = 0.014). Conclusion Our findings indicated that higher OPN expression is a potential biomarker to predict patient survival. Further study is necessary to investigate the role of OPN in the carcinogenesis of upper urinary tract UC.

Nuclear Factor of Activated T Cells Regulates Osteopontin Expression in Arterial Smooth Muscle in Response to Diabetes-Induced Hyperglycemia

Hyperglycemia is a recognized risk factor for cardiovascular disease in diabetes. Recently, we reported that high glucose activates the Ca(2+)/calcineurin-dependent transcription factor nuclear factor of activated T cells (NFAT) in arteries ex vivo. Here, we sought to determine whether hyperglycemia activates NFAT in vivo and whether this leads to vascular complications. An intraperitoneal glucose-tolerance test in mice increased NFATc3 nuclear accumulation in vascular smooth muscle. Streptozotocin-induced diabetes resulted in increased NFATc3 transcriptional activity in arteries of NFAT-luciferase transgenic mice. Two NFAT-responsive sequences in the osteopontin (OPN) promoter were identified. This proinflammatory cytokine has been shown to exacerbate atherosclerosis and restenosis. Activation of NFAT resulted in increased OPN mRNA and protein in native arteries. Glucose-induced OPN expression was prevented by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. The calcineurin inhibitor cyclosporin A or the novel NFAT blocker A-285222 prevented glucose-induced OPN expression. Furthermore, diabetes resulted in higher OPN expression, which was significantly decreased by in vivo treatment with A-285222 for 4 weeks or prevented in arteries from NFATc3(-/-) mice. These results identify a glucose-sensitive transcription pathway in vivo, revealing a novel molecular mechanism that may underlie vascular complications of diabetes.

Tissue expression of osteopontin (OPN) and mesothelin (MES) in malignant pleural mesothelioma (MPM). An immunohistochemical study of 70 consecutive cases

e22102 Background: There is still no single test that can reliably identify malignant mesothelial cells. Recently soluble MES and OPN have been proposed as novel serum markers for MPM but a definitive consensus on their use in routine is still lacking. This study aims at 1. analysing the essential pathological features of a series of consecutive MPMs from a single institution and 2. assessing the tumour tissue expression of OPN and MES and speculating about the potential biological role of these molecules in MPM. Methods: All MPMs diagnosed between 1999 and 2008 were retrieved from the archives of the Pathology Unit of Alessandria Hospital. All the diagnoses had been made on the basis of conventional light microscopy features supplemented by a mucin stain (periodic acid-Schiff with and without diastase treatment) and a panel of immunostains (carcinoembryonic antigen, CD15/LeuM1, BerEP4, calretinin and cytokeratin 5). Immunostaining for OPN (polyclonal antibody) and MES (monoclonal antibody, clone 5B2) was performed using the labelled streptavidin-biotin method, and the staining intensity and extent were assessed. Results: The study group consisted of 50 males and 20 females with a mean age at diagnosis of 78.4 years (range 47–92). Histopathology was epithelial, mixed, and sarcomatous in 52, 12, and 6 patients respectively. OPN positivity (percentage of positive tumour cells &gt;10%) was observed in 67 MPMs (96%) mostly in a granular cytoplasmic pattern and with an intensity ranging from weak (25%) to moderate (31%) and strong (44%). MES positivity (percentage of positive tumour cells &gt;10%) was recorded in 60 MPMs (86%), of which 36% exhibited a weak, 36% a moderate and 28% a strong immunostaining in a membrane pattern. MES was positive in 100% of epithelial MPMs, in 67% of mixed and in 0% of sarcomatous. Positivity was restricted to the epithelial component in mixed MPMs. Conclusions: The high expression of OPN in MPM, irrespective of the histotype, seems to point to a role of this molecule as a marker of malignant transformation of mesothelial cells, while the restriction of positive staining for MES to the epithelial phenotype supports a role of MES as a marker of epithelial differentiation in MPM. No significant financial relationships to disclose.

Benefit of radiotherapy dose escalation in localized prostate cancer with respect to expression of intrinsic markers of hypoxia

e16068 Background: Dose escalation improves the efficacy of prostate cancer radiotherapy (RT) at the cost of increased toxicity. Tumor hypoxia causes radioresistance, so the benefit of RT dose escalation may be greater in more hypoxic cancers. Methods: Cases had localized prostate cancer treated with neo-adjuvant androgen deprivation and radical RT at the Royal Marsden in two randomized trials of dose escalation (64 vs 74Gy). Tumour expression of three markers (vascular endothelial growth factor (VEGF), hypoxia inducible factor-1α(HIF-1α), and osteopontin) was assessed immunohistochemically using a semi-quantitative scale by a uro-pathologist, and analyzed with respect to freedom from biochemical failure (FFBF) using the Phoenix definition. Expression of each marker was dichotomised about the median for analysis of the impact of dose-escalation on outcome. Results: 201 cases with a median follow-up of 7 years were evaluable. Seven-year FFBF was 67% vs 40% (HR: 0.42, 95% CI 0.26–0.7, p=0.001) for 74 Gy versus 64Gy, respectively, among cases with high osteopontin expression, and 70% vs 82% (HR: 1.41, 95% CI 0.53–3.76, p=0.49) for 74Gy vs 64Gy among cases with low osteopontin expression. The benefit of RT dose escalation was similar regardless of VEGF or HIF- 1α expression. Conclusions: These data generate the hypothesis that osteopontin expression could inform RT dose individualisation. If validated, patients with low tumor expression of osteopontin could elect to receive less toxic, standard dose RT. No significant financial relationships to disclose.

Expression of integrin beta3 and osteopontin in endometrium of patients with adenomyosis

To investigate the expression of integrin beta3 and osteopontin (OPN) in eutopic and ectopic endometrium of adenomyosis. From January 2007 to July 2008, the endometrium specimens were collected from 43 patients with adenomyosis undergoing hysterectomy in Peking University First Hospital. Eutopic endometrium were 11 in proliferative phase and 32 in secretory phase (18 cases in mid-secretory phase) were collected. Ectopic endometriums were also collected. In the mean time, it was chosen 41 cases with pure subserous uterine myoma or cervical intraepithelial neoplasia (CIN) II-III treated by hysterectomy as controls including 12 endometrium in proliferative phase and 29 endometrium in secretory phase (19 cases in mid-secretory phase). The expression of Integrin beta3 subunit and OPN in the endometrium were assessed by immunohistochemical staining and quantitative real-time polymerase chain reaction. (1) Immunohistochemical staining showed that positive staining of integrin beta3 and OPN were present predominantly in eutopic and ectopic endometrial glandular epithelium. There was significant different protein expression of integrin beta3 and OPN, which were 1.6 +/- 0.8 and 1.7 +/- 0.7 in eutopic endometrium, 1.7 +/- 0.7 and 1.8 +/- 0.9 in ectopic endometrium, 2.1 +/- 0.9 and 2.0 +/- 0.9 in control endometrium (P < 0.05). The protein expression of integrin beta3 and OPN in eutopic endometrium of adenomyosis in the proliferative phase (0.8 +/- 0.4 and 0.7 +/- 0.3) were remarkably lower than those of the secretory phase (1.8 +/- 0.8 and 1.9 +/- 0.8, P < 0.01). The protein expression of integrin beta3 and OPN in the endometrium of controls in the proliferative phase (1.0 +/- 0.4 and 1.0 +/- 0.4) were significantly lower than those of the secretory phase (2.5 +/- 0.7 and 2.5 +/- 0.7) (P = 0.000). In the mid-secretory phase, the protein expression of integrin beta3 (2.0 +/- 0.9) and OPN (2.1 +/- 0.8) in eutopic endometrium of adenomyosis were significantly lower than that of control endometrium (2.7 +/- 0.5 and 2.7 +/- 0.7) (P < 0.01). (2) The mRNA expression level of integrin beta and OPN in eutopic and ectopic endometrium were assessed by quantitative real-time PCR (result was shown by median index). It was observed that integrin beta3 mRNA and OPN mRNA were significantly lower in the eutopic endometrium of adenomyosis (4.69 and 4.23), when compared with ectopic endometrium (7.96 and 14.84) and controls (13.47 and 17.40) (P < 0.05). Eutopic endometrium had higher mRNA expression of integrin beta and OPN mRNA in the secretory phase (5.54 and 11.40) than that in the proliferative phase (2.69 and 3.30) (P < 0.01). The mRNA expression level of integrin beta and OPN of control endometrium in the proliferative phase (3.12 and 4.75) were significantly lower than that in the secretory phase (19.94 and 21.00, P = 0.000). The mRNA expression of integrin beta and OPN were 10.10 and 14.34 in the mid-secretory phase, which were significantly lower than 21.50 and 24.18 in control endometrium (P < 0.05). High expression of integrin beta3 and OPN in ectopic endometrium of adenomyosis may cause endometriotic lesions; abnormal expression of integrin beta3 and OPN in the endometrium of adenomyosis during the implantation window may contribute to infertility in some patients.

High Expression of Osteopontin and CD44v6 in Odontogenic Keratocysts

Odontogenic keratocysts (OKCs) are more aggressive and more osteolytic lesions than dentigerous cysts (DCs) and radicular cysts (RCs). Osteopontin (OPN) is related to cancer metastasis and bone destruction. Binding of OPN to its cell membrane receptors integrin alphav and CD44v6 can enhance tumor cell motility, migration, invasion and spread. This study assessed the possible contribution of OPN, integrin alphav and CD44v6 to the local aggressive behavior and osteolytic ability of OKCs. We used an immunohistochemical method to examine the expression of OPN, integrin alphav and CD44v6 in tissue sections of 20 OKCs, eight DCs and 10 RCs. We found strong cytoplasmic OPN immunostaining in lining epithelial cells of 8 of 20 OKCs but not in any DCs and RCs. Positive OPN staining was also noted in the subepithelial connective tissue of four OKCs with intraepithelial expression of OPN. Diffuse and strong membranous integrin alphav staining was discovered in osteoclasts in all our tissue sections and in nearly all lining epithelial cells of DCs and RCs, but not in OKCs. In addition, diffuse and strong membranous CD44v6 staining was also observed in nearly all lining epithelial cells of OKCs, DCs and RCs. Binding of OPN to osteoclast cell membrane receptor integrin alphav can activate the osteoclasts and increase their osteolytic activity. In addition, binding of OPN to OKC lining epithelial cell membrane receptor CD44v6 can enhance the motility, migration, invasion and spread of lining epithelial cells into the surrounding cancellous bone. Therefore, we suggest that the local aggressive behavior and high osteolytic ability of OKCs in the jawbone can be explained at least partially by high expression of OPN and CD44v6 in lining epithelial cells of OKCs and high expression of integrin alphav in osteoclasts.

Osteopontin stimulates invasion of NCI‐h295 cells but is not associated with survival in adrenocortical carcinoma

Gene array studies indicated that osteopontin (OPN) mRNA is highly expressed in adrenocortical carcinomas (ACCs). OPN enhances invasiveness, proliferation, and metastasis formation, and is associated with poor survival in some malignant diseases. Integrin alphavbeta3 has been shown to mediate OPN effects on invasion. In this study, we demonstrated OPN and integrin alphavbeta3 expression in normal adrenal glands and benign adenomas, with staining seen exclusively in adrenocortical cells as well as even stronger staining in ACC. Western blot analysis confirmed overexpression of OPN in ACC (p < 0.01). With Matrigel invasion assays, we have shown that OPN greatly stimulates the invasiveness of NCI-h295 cells (>six-fold increase, p < 0.001). Transfection with integrin alphavbeta3 further increased invasiveness after OPN stimulation (p < 0.001). This increase was reversed by the addition of an anti-integrin beta3 antibody, indicating a functional relationship of OPN and integrin alphavbeta3 in ACC. With tissue arrays, we confirmed high OPN expression in 147 ACC samples. However, no association with survival was seen in Kaplan-Meier analysis including 111 patients with primary tumours graded for OPN staining and follow-up data available. In conclusion, our in vitro data indicate that OPN and integrin alphavbeta3 may act as a functional complex facilitating the invasiveness of adrenocortical tumours. This relationship remains of relevance to our understanding of carcinogenesis, but further studies are needed to address the physiological and pathological function of OPN in adrenal tissue.

Expression of osteopontin and its receptors in ameloblastomas

This study used an immunohistochemical method to examine the expression of osteopontin (OPN) in 30 ameloblastomas and of integrin alpha(v) and CD44v6 in 20 of these 30 ameloblastomas. We found that the positive staining rate in ameloblastomas was 87% for OPN, 45% for integrin alpha(v), and 90% for CD44v6. Both ameloblast-like and stellate reticulum-like cells showed a high expression of OPN and CD44v6. There was also a strong integrin alpha(v) immunostaining on the cell membrane of osteoclasts. Binding of OPN to osteoclast cell membrane receptor integrin alpha(v) can activate the osteoclast and increase its osteolytic activity. In addition, binding of OPN to ameloblastoma tumor cell membrane receptor CD44v6 can enhance tumor cell migration, invasion and spread. Therefore, we suggest that the local aggressive behavior and high osteolytic ability of ameloblastomas in the jawbones can be explained by the high expression of OPN and CD44v6 in ameloblastoma cells and the high expression of integrin alpha(v) in osteoclasts.

P.159 A study of odontogenic tumors by the new WHO classiflcation

This study used an immunohistochemical method to examine the expression of osteopontin (OPN) in 30 ameloblastomas and of integrin αv and CD44v6 in 20 of these 30 ameloblastomas. We found that the positive staining rate in ameloblastomas was 87% for OPN, 45% for integrin αv, and 90% for CD44v6. Both ameloblast-like and stellate reticulum-like cells showed a high expression of OPN and CD44v6. There was also a strong integrin αv immunostaining on the cell membrane of osteoclasts. Binding of OPN to osteoclast cell membrane receptor integrin αv can activate the osteoclast and increase its osteolytic activity. In addition, binding of OPN to ameloblastoma tumor cell membrane receptor CD44v6 can enhance tumor cell migration, invasion and spread. Therefore, we suggest that the local aggressive behavior and high osteolytic ability of ameloblastomas in the jawbones can be explained by the high expression of OPN and CD44v6 in ameloblastoma cells and the high expression of integrin αv in osteoclasts.

Osteopontin Expression Correlates with Angiogenesis and Survival in Malignant Astrocytoma

Osteopontin (OPN) is a phosphorylated glycoprotein with diverse functions including angiogenesis, cancer development, invasion and metastasis. The aim of the study was to analyze the expression of OPN in human astrocytomas and to correlate it with angiogenesis and patients' outcome. Seventy-six human astrocytomas including eight pilocytic astrocytomas (grade I), 10 diffuse astrocytomas (grade II), 8 anaplastic astrocytomas (grade III) and 50 glioblastomas (grade IV) were immunohistochemically stained for OPN protein. The distribution of OPN staining (cytoplasmic and/or interstitial) was assessed and compared to microvessel number and patients' survival. In normal brain tissue some glial and neuronal cells showed weak cytoplasmic staining, while interstitium was negative. Astrocytomas were heterogeneous regarding the OPN expression. High cytoplasmic OPN expression in glioblastomas was associated with poor patients' survival (p = 0.012). Also, we found the association of interstitial OPN expression and angiogenesis (p = 0.033), i.e. the number of newly formed blood vessels was higher in tumors showing high interstitial OPN expression. Our results indicate the overexpression of OPN protein in astrocytoma cells and suggest the role of OPN in astrocytoma progression and angiogenesis.

Protein Expression of Osteopontin in Tumor Tissues Is an Independent Prognostic Indicator in Gastric Cancer

Objective: Osteopontin has been shown to facilitate the progression and metastasis of malignancies and to be of prognostic value in several human cancers. In gastric cancer, the protein expression of osteopontin has been found to be correlated with tumor invasion and metastasis, but data on its prognostic value are lacking. The aim of this study was to classify the prognostic significance of osteopontin in gastric cancer. Method: In this retrospective study, 306 tumor tissue samples resected from patients with gastric cancer were investigated by staining with a commercial polyclonal antibody against osteopontin. Results: Positive osteopontin expression (>5% of the cancer cell cytoplasm positive) was found in 132 (43.1%) of 306 stained tumors. High osteopontin expression correlated with deep invasion, lymph node metastasis, distant metastasis and higher TNM stage. Patients with osteopontin-positive expression had poorer overall and disease-free survivals than those with negative expression (p < 0.001 for both). Multivariate analysis revealed osteopontin expression as an independent prognostic indicator of poor disease-free and overall survival in patients with gastric cancer, particularly for survival in TNM stages II (p < 0.05) and III (p < 0.01) patients. Conclusion: Osteopontin protein expression was confirmed as a new independent predictor of tumor recurrence and poor prognosis in patients with gastric cancer.

Elevation of osteopontin levels in brain tumor cells reduces burden and promotes survival through the inhibition of cell dispersal

Osteopontin (OPN) is a pleotrophic molecule that has been associated with multiple disorders of the central nervous system (CNS). Its roles in CNS malignancy are unclear but suggest that higher levels of OPN expression correlate with increased tumor grade and increased migratory capacity of tumor cells. In this study OPN cDNA was cloned into a retroviral vector and used to infect F98 Fischer rat-derived glioma cells and U87 human-derived glioblastoma multiforme (GBM) cells in vitro. Cells expressing high levels of OPN migrated less distance than control cells in vitro. This effect was not RGD mediated, but was reversed in the presence of c-Jun N-terminal kinase (JNK) inhibitor suggesting that JNK1 is an essential component of a negative feedback loop affecting OPN activated signaling cascades. Implantation of tumor cells expressing high levels of OPN into adult Fischer rats and nude rats resulted in morphologically distinct tumors and prolonged host survival relative to controls. We propose that local produced, high level OPN expression limits the malignant character of glioma cells and that the downstream mechanisms involved represent pathways that may have therapeutic value in the treatment of human CNS malignancy.

Expression of osteopontin, a target gene of de‐regulated Wnt signaling, predicts survival in colon cancer

Osteopontin (OPN) is a secreted phosphoprotein, which has been reported to be associated with tumor progression in numerous solid tumors. In a previous transcriptome study on colorectal cancer, we identified the gene OPN among the most strongly up-regulated transcripts. OPN has been suggested as a putative target of Wnt signaling, but the molecular mechanism responsible for its aberrant transcription is not fully understood. We analyzed 13 normal colon tissues, 9 adenomas, 120 primary colon tumors, and 10 liver metastases by quantitative reverse-transcription PCR. OPN expression was strongly elevated in primary colon cancer and liver metastasis, but not in pre-cancerous lesions and UICC stage I tumors. Multivariate analysis established OPN expression as an independent prognostic parameter for overall survival. Moreover, high OPN expression identified a subgroup of patients with bad prognosis. Next, we determined immunohistochemically a correlation of OPN expression with aberrant beta-catenin staining, which is indicative of Wnt activation. Elevated expression of OPN was significantly correlated with increased cytoplasmic and nuclear beta-catenin staining. The in vivo role of Wnt signaling for the expression of OPN was tested in genetically defined mouse models with (Apc(1638N)) or without (pvillin-KRAS(V12G)) Wnt activating mutations. Mutation of the tumor suppressor APC was necessary for upregulation of OPN expression in the murine tumors on transcript and on protein levels. Thus, OPN is a transcriptional target of aberrant Wnt signaling, and OPN expression alone predicts survival in human colon cancer.

Osteopontin is linked to p65 and MMP‐9 expression in pulmonary adenocarcinoma but not in malignant pleural mesothelioma

Osteopontin (OPN) is a matricellular protein involved in tissue remodelling, cell-mediated immunity and malignant transformation. High OPN serum levels predict poor prognosis in non-small cell carcinoma and set patients with malignant pleural mesothelioma (MM) apart from disease-free asbestos-exposed individuals. Yet neither the spectrum of tissue expression nor the signalling pathways of OPN in MM and pulmonary adenocarcinoma have been characterized, although in vitro evidence links OPN to the epidermal growth factor receptor (EGFR) pathway. The aim of this study was to address these deficiencies. OPN expression was investigated immunohistochemically in 104 adenocarcinomas and 38 MM and correlated with histological features, including tumour type, grade and proliferation and with expression of activated intermediary EGFR signalling pathway molecules p65, p-AKT, p-ERK, p-STAT-3, and of metalloproteinase (MMP)-1, MMP-2 and MMP-9. In MM, OPN expression was widespread (36/38) and independent of the molecular parameters studied. In adenocarcinoma, high OPN expression was correlated with expression of p65, p-ERK and MMP-9. Frequent OPN expression is typical of, but not specific for MM, whereas it appears to select adenocarcinoma cases with p65 and MMP-9 expression, suggesting a link with EGFR signalling pathways.

The regulation and role of osteopontin in malignant transformation and cancer

Osteopontin (OPN) is a predominantly secreted extracellular matrix glycophosphoprotein which binds to alpha v-containing integrins and has an important role in malignant cell attachment and invasion. High OPN expression in the primary tumor is associated with early metastasis and poor outcome in human breast and other cancers. Forced OPN overexpression in benign cells may induce neoplastic-like cell behaviour including increased attachment and invasion in vitro as well as the ability to metastasize in vivo. Conversely, OPN inhibition by antisense cDNA impedes cell growth and tumor forming capacity. OPN is not mutationally activated in cancer but its expression is regulated by Wnt/Tcf signaling, steroid receptors, growth factors, ras, Ets and AP-1 transcription factors. Presumably these factors are implicated in induction of OPN overexpression in cancer. Greater understanding of the role of OPN in neoplastic change and its transcriptional regulation may enable development of novel cancer treatment strategies.

Osteopontin dysregulation and lytic bone lesions in multiple myeloma

Osteopontin (OPN), a secreted phosphoprotein involved in immune regulation and bone homeostasis, is a major component of bone, the natural habitat of long-lived plasma cells and multiple myeloma (MM). We show that only some MM cell lines and primary patient samples express OPN at high levels. High OPN expression inversely correlates with bone disease. When we subdivide MM into molecular subtypes, OPN is significantly upregulated in patients with maf translocations, particularly in the fraction lacking bone disease. OPN is produced in osteolytic lesions: we propose that MM-derived OPN plays a critical role in bone disease by protecting bone from destruction.