Expression Pattern Of Osteopontin Research Articles

Differential expression of epithelial and smooth muscle lineage-specific markers of metanephros in one-humped camel foetuses.

The development of the metanephros in one-humped camels involves a complex series of interactions between epithelial and mesenchymal cells. As a result, there is a synchronized differentiation process of stromal, vascular and epithelial cell types during glomerulogenesis, angiogenesis and tubulogenesis. In the current work, the metanephros of camel foetuses were divided into four stages where kidneys from each stage were processed and immunoassayed, followed by quantitative analysis to determine target protein intensities throughout metanephrogenesis in the camel. This study demonstrated robust expression of α-smooth muscle actin (α-SMA) in the glomerular mesangium, as well as in interlobular and glomerular arterioles during the earlier stages of development. However, in the late stages, α-SMA expression became more localized around the blood capillaries in both the cortex and medulla. Strong expression of CD34 was observed in the immature glomerular and peritubular endothelial cells within the subcapsular zone, as well as in the glomerular, proximal tubular and distal tubular epithelium of stage one foetuses, although its expression gradually diminished with foetal maturation. The expression pattern of osteopontin was prominently observed in the distal convoluted tubules throughout all stages, however, no expression was detected in the proximal tubules, glomeruli and arterioles. E-cadherin was detected in the developing renal tubular epithelial cells but not in the glomeruli. In conclusion, this study reveals the spatiotemporal distribution of key proteins, including α-SMA, CD34, Osteopontin and E-cadherin, which play a crucial role in metanephrogenesis in camel foetuses.

A Dual Role of Osteopontin in Modifying B Cell Responses.

The occurrence of B cell aggregates within the central nervous system (CNS) has prompted the investigation of the potential sources of pathogenic B cell and T cell responses in a subgroup of secondary progressive multiple sclerosis (MS) patients. Nevertheless, the expression profile of molecules associated with these aggregates and their role in aggregate development and persistence is poorly described. Here, we focused on the expression pattern of osteopontin (OPN), which is a well-described cytokine, in MS brain tissue. Autopsied brain sections from MS cases with and without B cell pathology were screened for the presence of CD20+ B cell aggregates and co-expression of OPN. To demonstrate the effect of OPN on B cells, flow cytometry, ELISA and in vitro aggregation assays were conducted using the peripheral blood of healthy volunteers. Although OPN was expressed in MS brain tissue independent of B cell pathology, it was also highly expressed within B cell aggregates. In vitro studies demonstrated that OPN downregulated the co-stimulatory molecules CD80 and CD86 on B cells. OPN-treated B cells produced significantly lower amounts of IL-6. However, OPN-treated B cells also exhibited a higher tendency to form homotypic cell aggregates in vitro. Taken together, our data indicate a conflicting role of OPN in modulating B cell responses.

Osteopontin is differentially expressed in renal cell tumors

ABSTRACT Osteopontin (OPN) has been shown to play a significant role in regulating the aggressiveness of cancer cells and promote tumor growth. Evaluation of this phosphorylated extracellular glycoprotein expression may help estimate its use as a potential prognostic marker in tumorigenesis of different renal tumors. The objective of the present study was to characterize for the first time the expression pattern of OPN in primary renal tumors and correlate its association to tumor progression and survival. A total of 68 primary renal tumors (clear cell renal cell carcinoma, oncocytoma, renal cell carcinoma, invasive urothelial carcinoma, papillary renal cell carcinoma, chromophobe renal cell carcinoma, papillary urothelial carcinoma) were analyzed by immunohistochemical staining and Western blot methods. Expression of OPN in relation to grading, histologic type of tumor, and survival was statistically assessed. Study data demonstrated that OPN is differentially expressed in various renal tumor cells types. It was shown that OPN is predominantly expressed at the protein level in clear cell renal cell carcinoma when compared to other types of renal tumors. In conclusion, osteopontin may be involved in the pathogenesis of renal tumors. However, the role of OPN expression in predicting the biological response requires further evaluation.

Hypoxia induces differential expression patterns of osteopontin and CD44 in colorectal carcinoma.

The plasma protein osteopontin (OPN) is considered to be a tumor biomarker, where elevated plasma levels are associated with poor prognosis. Additionally, OPN is expressed in the presence of tumor hypoxia, which is an adverse prognostic factor in radiation oncology. One of its receptors, the proposed tumor stem cell marker CD44, is also associated with aggressive tumors, shown for example in colon cancer. The expression of CD44 and its splice variants (particularly CD44v6) can be upregulated by OPN itself. In the present study, we aimed to investigate the influence of hypoxia on the expression of OPN and its binding partners CD44 and CD44v6 in colon carcinoma cell lines invitro, using SW480, SW620, HT29 and HCT116 cells. Additionally, we investigated the effect of irradiation on the expression pattern of OPN and its ligands, and the influence of hypoxia on the clonogenic survival of the cells after irradiation. While the expression patterns were nearly unaltered by irradiation, hypoxia led to an upregulation of OPN protein expression and an increase in the radioresistance in all tested colorectal carcinoma cell lines. However, a similar clear statement with regard to the expression of CD44 and CD44v6 is not possible. We hypothesize that the OPN receptors differ in their expression pattern between cell lines depending on the degree of their malignancy.

Increased osteopontin expression is associated with progression from vulvar precancerous lesions to vulvar squamous cell carcinoma

Vulvar squamous cell carcinoma (VSCC) contributes to about 3-5% of all gynecological cancers. Vulvar intraepithelial neoplasia (VIN) and vulvar lichen sclerosus (VLS) are regarded as precancerous lesions. Early detection and treatment of precancerous lesions may prevent development of VSCC. Osteopontin (OPN) has been shown to be involved in many physiological and pathological processes, such as tumor progression, by promoting cancer cell invasion and metastasis. As a result of these findings, OPN has been described as a potential marker for tumor progression in some malignancies. In this study, we investigated the expression of OPN in vulvar tissue specimens and compared its expression between different histopathological grades. In the present study, the expression patterns of OPN in 80 paraffin-embedded tissue specimens, including 25 VSCC samples, 21 VIN lesions and 21 VLS, in addition to 13 normal vulvar samples, were examined by the immunohistochemical method and chromogenic in situ hybridization. The intensity of OPN expression steadily increased according to the pathological grades. In addition, OPN staining was found in the extracellular matrix in VSCC. Expression levels of OPN increased from VLS and VIN to VSCC, and steadily increased with the pathological stage of VSCC. Our results suggest that OPN may be associated with the progression of VSCC.

Expression pattern of osteopontin and v 3 integrin during the implantation window in infertile patients with early stages of endometriosis

To study endometrial receptivity in terms of osteopontin (OPN) and αvβ3 integrin expression and co-expression in infertile women with early stages of endometriosis. We investigated the immunohistochemical expression and co-expression of OPN and αvβ3 integrin in the endometrium of 20 infertile patients with Stage I or II endometriosis as the only detectable cause of infertility, 20 infertile patients with unexplained infertility and 20 fertile women undergoing tubal sterilization. Two endometrial biopsies were performed during a single menstrual cycle (postovulatory Day +7 to +8 and 4 days later) in each subject. No statistically significant differences regarding OPN and αvβ3 integrin expression were found between infertile patients with endometriosis and the two control groups. There was no significant correlation between OPN and αvβ3 integrin staining intensity in the mid-luteal phase biopsies in any of the groups studied. Endometrial OPN and αvβ3 integrin expression or co-expression is not impaired during the window of implantation in patients with Stage I-II endometriosis. Further studies are needed to determine whether these results imply normal endometrial receptivity in such patients or add to the increasing uncertainty about the clinical value of assessing the endometrium with these markers of implantation.

Effect of anorganic bovine bone to autogenous cortical bone ratio upon bone remodeling patterns following maxillary sinus augmentation

Maxillary sinus augmentation is a predictable implant site development technique, although several local and systemic factors may influence outcomes. The aim of this study was to evaluate healing patterns and bone remodeling activity following the use of two different graft mixtures for maxillary sinus augmentation. Patients in need of maxillary sinus augmentation were randomly assigned to two different groups. A graft mixture using a 50% autologous bone (AB) to 50% anorganic bovine bone (ABB) ratio was used in group 1, while a 20% AB to 80% ABB ratio was utilized for group 2. After a 6-month healing period, bone core biopsies were harvested for histological, histomorphometrical, and immunohistochemical analyses. Twenty-eight subjects participated in this study. No statistically significant differences were found between groups in regards to vital bone and non-mineralized tissue proportions. Higher number of osteoid lines (18.05 ± 10.06 in group 1 vs. 9.01 ± 7.53 in group 2; P = 0.023) and higher cellularity, particularly regarding the number of osteocytes (631.85 ± 607.98 in group 1 vs. 219.08 ± 103.26 in group 2; P = 0.002), were observed in specimens from group 1. Differences in expression patterns of osteopontin and tartrate-resistant acid phosphatase were also detected between groups. AB to ABB ratio appears to influence bone remodeling patterns and cell content following maxillary sinus augmentation procedures. Similar proportion of vital bone was found in specimens obtained from both groups. More cellular presence was observed in samples containing higher proportions of AB.

Osteopontin-positive infiltrating tumor-associated macrophages in bulky ampullary cancer predict survival

Purpose: Tumor-associated macrophages (TAMs) promote cancer cell proliferation and distant metastases. Osteopontin (OPN) is overexpressed in several human cancer cells and in TAMs. Therefore, we set out to determine the role of OPN-expressing macrophages in cancer. Experimental Design: Specimens from ampullary cancer patients at National Cheng Kung University Hospital were collected for immunohistochemistry. Plasma OPN was measured by enzyme-linked immunosorbent assay. Tumor and normal epithelial cells from fresh tissues were separated by laser-assisted microdissection for reverse-transcription polymerase chain reaction and quantitative real-time PCR analyses. Results: In 100 ampullary cancers, diffuse cytoplasmic positivity for OPN was found in infiltrating TAMs in 36 patients and marginal TAMs in 32 patients; OPN+ macrophages were absent in 32 patients. Expression patterns of OPN in TAMs were associated with pancreatic invasion, tumor stage, TNM stage, lymphovascular invasion and recurrence with peritoneal carcinomatosis. Patients were stratified according to a median tumor size of 2 cm. Patients with tumor sizes ≥2 cm and OPN+ infiltrating TAMs had a poorer disease-specific survival rate than those with OPN+ marginal TAMs. Macrophage-associated cytokine expression in ampullary cancer cells was also assessed; levels of macrophage migration inhibitory factor (MIF) in cancer cells were higher than in normal duodenal mucosa. Conclusions: Expression of OPN and location of TAMs in bulky ampullary cancer predict recurrence. In addition, cytoplasmic staining of MIF is enhanced in ampullary cancer cells. Patients with bulky tumor, OPN+ infiltrating TAMs and MIF expression had a worst disease-specific survival.

Expression Pattern of Osteopontin in Endometrial Carcinoma: Correlation With Expression of the Adhesion Molecule CEACAM1

Osteopontin (OPN) and CEACAM1 have diverse biological functions in the uterus and placenta throughout the estrous cycle and pregnancy and have been shown to interact with integrin beta3. OPN is a glycoprotein of the extracellular matrix, which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. Recently we showed the expression pattern of OPN in gestational trophoblastic tumors. CEACAM1 is an adhesion molecule of the carcinoembryonic antigen family that we have recently found to be expressed in endometrial cancer and that has been shown to be down-regulated in colorectal, prostate, and breast cancer. In this study, immunohistochemistry and immunofluorescence with specific antibodies were performed on a series of 20 normal endometrial samples, 17 endometrial hyperplasias, and 43 endometrial carcinomas (28 endometrioid, 10 serous, and 5 clear cell carcinomas) to investigate the expression pattern and cell-type specific localization of OPN and to correlate it with the expression of CEACAM1. In addition, Western blot was performed on normal human endometrium and endometrial neoplasia. Strong OPN expression with a consistent cytoplasmic localization in epithelial glandular cells was observed in the normal human endometrium in 80% of the samples of the proliferative and secretory phase (score 8-12). Similar results could be found in endometrial hyperplasias. Strong expression of OPN could be observed in 29 (67.4%) of the 43 analyzed endometrial carcinomas. Of the 43 analyzed tumors, 18 (41.8%) were in the high score (8-12) category with a strong OPN expression level; 11 of 43 (25.5%) showed a moderate score (4-7) category. In endometrioid carcinoma with increasing malignancy grade, increasing areas with low OPN expression level or complete loss of OPN expression could be observed. In contrast, serous tumors showed a strong OPN expression level. Similar results could be found in Western blot analysis. CEACAM1 showed similar results and could be found to be coexpressed with OPN in normal human endometrium and in endometrial neoplasia as we showed using immunofluorescence. In this study, the different expression patterns of OPN in endometrial tumors could additionally support the biological diversity of endometrioid and serous carcinomas together with other markers. We suggest that OPN might play a different role in the pathogenesis of endometrial cancer (possibly as a functional complex with CEACAM1) and could be relevant for invasive growth of such lesions.

Expression pattern of osteopontin (OPN) in human adrenal tissues and in NCI259R cells

Objectives: Osteopontin (OPN) is a glycoprotein of the extracellular matrix, which we previously found to be expressed in benign and malignant endocrine tissues of the utero-placental system, and which was shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. Recently, expression profiling of adrenal neoplasms revealed OPN mRNA to be expressed in these tumors. The present study was designed to analyze the expression profiling of OPN protein in normal and tumorous adrenal tissues.

Osteopontin Expression in Gestational Trophoblastic Diseases: Correlation With Expression of the Adhesion Molecule, CEACAM1

The human placenta is a complex tissue with multiple endocrine and nutritional functions and a unique capacity for rapid proliferation but tightly controlled invasion, differentiating it from malignant tumors. Osteopontin (OPN) is a glycoprotein of the extracellular matrix, which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. OPN also could be implicated in regulating implantation and placentation by promoting cellular migration and invasion in a placenta-specific fashion. We could demonstrate the expression pattern of OPN in the normal human placenta in which it is localized in the extravillous (intermediate) trophoblast and the villous cytotrophoblast. CEACAM1 is an adhesion molecule, which we have recently found to be expressed at the maternal-fetal interface of the normal placenta with a localization to the extravillous (invasive) trophoblast and in gestational trophoblastic disease (GTD) and also to be potentially implicated in trophoblast invasion and tumorigenesis. Both OPN and CEACAM1 have been shown to interact with integrin beta3. The purpose of this study was to investigate the expression pattern of OPN in GTD and to correlate it with the expression of CEACAM1. To analyze the expression of OPN, we performed immunohistochemistry on a total of 27 cases of GTD, including 21 hydatidiform moles and 6 choriocarcinomas, which had previously been characterized with respect to their CEACAM1 expression. Hydatidiform moles showed a positivity for OPN in villous cytotrophoblast and in the trophoblast proliferations on the villous surface. The strongest OPN expression could be observed in the choriocarcinomas with a heterogenous OPN expression pattern. CEACAM1 had shown similar results and was found to be expressed in choriocarcinoma. The expression pattern of osteopontin in gestational trophoblastic diseases indicates that it might play a role in the pathogenesis of GTD (possibly as a functional complex with CEACAM1 and integrin beta3) and might be useful as an additional diagnostic marker for such lesions.

Expression pattern of osteopontin (OPN) in the human placenta – correlation with expression of the adhesion molecule CEACAM1

The human placenta is a complex tissue with multiple endocrine and nutritional functions and a unique capacity for rapid proliferation but tightly controlled invasion, differentiating it from malignant tumors. The cytokine osteopontin (OPN) is a glycoprotein of the extracellular matrix which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. OPN could thus also be implicated in regulating implantation and placentation by promoting cellular migration and invasion in a placenta-specific fashion. The expression pattern and cell-type specific localization of OPN in the human placenta has not been described so far. CEACAM1 is an adhesion molecule which we have recently found to be expressed at the maternal-fetal interface with a localization to the extravillous (invasive) trophoblast and to be potentially implicated in trophoblast invasion. Both OPN and CEACAM1 have been shown to interact with integrin beta3. In the present study, immunohistochemistry with specific antibodies was performed to investigate the expression pattern and cell-type specific localization of OPN in the human placenta, and to correlate it with the expression of CEACAM1. Parallel sections of 50 normal placentas where analysed for OPN and CEACAM1 expression. All placentas presented very strong expression of OPN in the extravillous (invasive) trophoblast (80% positive cells), which correlated with expression of CEACAM1. In addition, OPN was also present in the villous trophoblast, with strongest expression in the cytotrophoblast of the first trimester, while CEACAM1 was not expressed in the villous trophoblast. These data show that OPN is specifically expressed in the human placenta with strongest expression levels in the extravillous (invasive) trophoblast, where it correlates with expression of CEACAM1 and could thus contribute in the regulation of trophoblast invasion in a CEACAM1-involving mechanism as well as play an additional role in cytotrophoblast function.