Expression of bone-related protein messenger RNA in human meningiomas: possible involvement of osteopontin in development of psammoma bodies

Osteopontin and Ki-67 expression in World Health Organization graded canine meningioma

Osteopontin (OPN) is a matrix protein involved in tumour initiation and progression. In human meningioma, OPN has been correlated with World Health Organization (WHO) grade, brain invasion and recurrence. The aim of this study was to investigate OPN as a possible malignancy marker in canine meningioma by correlating its expression to WHO grade and proliferative activity as measured by the Ki-67 labelling index (LI). Thirty-five formalin-fixed, paraffin-embedded canine meningioma samples were classified according to the current human WHO classification. Evaluation of OPN expression was performed by immunohistochemical (IHC) labelling and calculation of the OPN intensity score (IS), OPN IHC score and Allred score. The scores were compared with WHO grades, Ki-67 LI, location and invasiveness. Nineteen meningiomas were graded as WHO grade I (54.3%), nine as grade II (25.7%) and seven as grade III (20.0%). Twenty-six tumours were located intracranially, four were retrobulbar and five were spinal meningiomas. In all specimens OPN expression was detected in moderate to high degrees. Neither the OPN scores nor the Ki-67 LIs were correlated with WHO grades. However, the OPN IS and OPN IHC score were significantly higher in WHO grade I samples compared with grade II samples (P <0.05). The OPN IS and OPN IHC score were significantly lower in meningioma samples that invaded surrounding tissues (P = 0.01 and 0.019, respectively). The results indicate a generally high expression of OPN in canine meningioma independent of WHO grade. Further research into the role of OPN as a possible therapeutic target or predictor of recurrence is warranted.

The Expression of miR-155-5p and Local Matrix Gla Protein in Meningiomas

Meningiomas are classified by the World Health Organization (WHO) in three grades, based on morphological features. Independent of this grading, the presence of calcification in meningiomas influences their growth rate. The messenger RNA of matrix Gla protein (MGP), an extra-hepatic protein with different conformations involved in the homeostasis of ectopic calcification has been found in meningiomas and was shown to be regulated in breast cancer by miR-155-5p, a specific micro RNA. Therefore, we investigated the expression of miR-155-5p and its relationship with local MGP conformations in different grade meningiomas. According to the WHO classification, our 41 samples of meningiomas were stratified in groups WHO I and WHO II. Using real time polymerase chain reaction, we observed a higher miR-155-5p expression in group WHO I versus group WHO II [with a fold change (FC) of 3.83, p=0.027)]. Moreover, the expression of miR-155-5p was higher in calcified tumors compared to non-calcified tumors in all samples (FC=3.01, p=0.047) and in group WHO I (FC=3.65, p=0.048). Utilizing immunohistochemistry, we determined the concurrent presence of all MGP conformations in calcified meningiomas. This study was the first to establish higher miR-155-5p expression in grade WHO I and calcified meningiomas, which could improve molecular classification and targeted therapy and also the presence of all MGP conformations in calcified meningiomas, confirming the existence of an anti-calcification mechanism in meningiomas..

Molecular Aspects of Thyroid Calcification

In thyroid cancer, calcification is mainly present in classical papillary thyroid carcinoma (PTC) and in medullary thyroid carcinoma (MTC), despite being described in benign lesions and in other subtypes of thyroid carcinomas. Thyroid calcifications are classified according to their diameter and location. At ultrasonography, microcalcifications appear as hyperechoic spots ≤ 1 mm in diameter and can be named as stromal calcification, bone formation, or psammoma bodies (PBs), whereas calcifications > 1 mm are macrocalcifications. The mechanism of their formation is still poorly understood. Microcalcifications are generally accepted as a reliable indicator of malignancy as they mostly represent PBs. In order to progress in terms of the understanding of the mechanisms behind calcification occurring in thyroid tumors in general, and in PTC in particular, we decided to use histopathology as the basis of the possible cellular and molecular mechanisms of calcification formation in thyroid cancer. We explored the involvement of molecules such as runt-related transcription factor-2 (Runx-2), osteonectin/secreted protein acidic and rich in cysteine (SPARC), alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteopontin (OPN) in the formation of calcification. The present review offers a novel insight into the mechanisms underlying the development of calcification in thyroid cancer.

Endoscopic Endonasal Removal of Large Calcified Pituitary Adenoma: Case Report and Review of the Literature

BACKGROUND

Large calcified intrasellar masses, called pituitary stones, have been reported as calcified pituitary adenomas in the literature. Although relatively rare, calcified pituitary adenomas appear in various formations. Thus, whether the lesion is removable-and, if so, which approach is appropriate-mainly depends on its formation and quality.

CASE DESCRIPTION

A 46-year-old woman presented with visual loss and amenorrhea. Although computed tomography showed a uniformly calcified sellar tumor, magnetic resonance imaging displayed heterogenous intensity on T2-weighted images and mild gadolinium enhancement, suggesting that the lesion was a mixture of pituitary adenoma and fine calcification. Thus, we undertook tumor resection via an endoscopic endonasal approach, which resulted in total removal. The pathological diagnosis was a pituitary adenoma with rich calcification.

CONCLUSIONS

We report a rare case of a large pituitary stone that was successfully removed via an endoscopic endonasal approach. This could therefore be a feasible, effective technique for the removal of pituitary stones, although careful analysis of preoperative magnetic resonance imaging is required.

OPNa Overexpression Is Associated with Matrix Calcification in Thyroid Cancer Cell Lines

Osteopontin (OPN) spliced variants (OPN-SV: OPNa, OPNb, and OPNc) are aberrantly expressed in tumors and frequently associated with cancer progression. This holds true for papillary thyroid carcinoma (PTC), which is the most common type of thyroid cancer (TC). PTC often presents with desmoplasia and dystrophic calcification, including psammoma bodies (PB). This work aimed to investigate total OPN (tOPN) and OPN-SV expression and their association with the presence of PB in the PTC classical variants (cPTC), as well as the involvement of OPN-SV in matrix calcification of TC cell lines. We found that cPTC samples presenting PB showed higher OPN expression levels. In TC cell lines, OPNa overexpression promotes higher matrix calcification and collagen synthesis when compared to that of clones overexpressing OPNb or OPNc. In response to OPN knockdown, calcification was inhibited, paralleled with the downregulation of calcification markers. In conclusion, our data evidenced that OPN expression is associated with the presence of PB in cPTC samples. Among the OPN-SV, OPNa is the main contributor to matrix calcification in tested TC cells, providing clues to a better understanding on the biology and ethiopathogenesis of the calcification process in TC cells.

Matrix Gla protein in tumoral pathology

Matrix Gla protein is a vitamin K-dependent protein secreted by chondrocytes and vascular smooth muscle cells. The presence of matrix Gla protein was reported in arterial and venous walls, lungs, kidney, uterus, heart, tooth cementum and eyes. Several studies identified matrix Gla protein in tumoral pathology.

Until recently, it was thought to only have an inhibitory role of physiological and ectopic calcification. New studies demonstrated that it also has a role in physiological and pathological angiogenesis, as well as in tumorigenesis.

The aim of this review is to report the latest findings related to the expression and clinical implications of matrix Gla protein in different types of cancer with an emphasis on cerebral tumors.

18F-Fluoride PET/CT allows detection of hyperostosis and osseous involvement in meningioma: initial experience

PURPOSE

The present study was conducted to assess the diagnostic performance of (18)F-fluoride PET/CT in evaluating hyperostosis and osseous involvement in patients with meningioma.

PATIENTS AND METHODS

Thirty-four patients with meningioma (mean age, 61 years) underwent (18)F-fluoride PET/CT before surgery. In 24 patients (71%), (18)F-FDG PET/CT was also given before surgery, and the results were compared. The images were reviewed by 2 board-certified nuclear medicine specialists who were unaware of any clinical information and a consensus was reached. Uptake patterns and measurements of tracers were compared with pathological findings from resected specimens, with hyperostosis and osseous involvement as the reference standard.

RESULTS

There were 27 grade I tumors (79%) and 7 grade II tumors (21%). The primary tumor focus was identified in each patient using both (18)`F-fluoride PET/CT and (18)F-FDG PET/CT, but there were no significant correlations in the degree of uptake between the 2 tracers. The SUV(max), SUV(max) corrected for lean body mass (SUL(max)), and tumor metabolic volume (TMV) for (18)F-fluoride and (18)F-FDG were greater in grade II tumors than in grade I tumors. Hyperostosis and osseous involvement was identified in 12 tumors (38%). The SUV(max), SUL(max), and TMV of tumors visualized with (18)F-fluoride PET/CT were greater in tumors with hyperostosis and osseous involvement than in those without (P = 0.005, P = 0.003, and P = 0.006, respectively). In contrast, the SUV(max), SUL(max), and TMV of tumors visualized with (18)F-FDG PET/CT were similar regardless of hyperostosis or osseous involvement.

CONCLUSIONS

(18)F-fluoride PET/CT may improve detection of hyperostosis and osseous involvement in patients with meningioma.

Osteopontin expressions correlate with WHO grades and predict recurrence in meningiomas

Recurrence of meningiomas is a major prognostic issue. Although World Health Organization (WHO) histopathological grading correlates strongly with recurrence, it has some limitations, and predicting the biological behavior of grade I meningiomas is particularly difficult. Osteopontin (OPN) is a protein known to be involved in tumor progression. The purpose of this study is to determine expression of OPN in meningiomas and to investigate its correlation with WHO grades and tumor recurrence. Immunohistochemical (IHC) evaluation of expression of OPN was performed by two different methods to ensure reliability. OPN IHC and Allred scores were calculated on the basis of intensity and extent of staining. Both scores were in agreement and correlated significantly with meningioma grade and Ki-67 index. OPN scores were also significantly correlated with recurrence of WHO grade I meningiomas. Cut-off values for OPN IHC and OPN Allred scores between non-recurrent and recurrent grade I meningiomas were calculated as 70 and 5.5 respectively. We concluded that OPN is a valuable marker for grading meningiomas and for predicting the recurrence in WHO grade I tumors.

Biomolecular mechanism of urinary stone formation involving osteopontin

Urinary stones consist of two phases-an inorganic (mineral) phase and an organic (matrix) phase. Studies on the organic components of kidney stones have been undertaken later than those on the inorganic components. After osteopontin was identified as one of the matrix components, the biomolecular mechanism of urinary stone formation became clearer. It also triggered the development of new preventive treatments. Osteopontin expression is sporadically observed in normal distal tubular cells and is markedly increased in stone-forming kidneys. Calcium oxalate crystals adhering to renal tubular cells are incorporated into cells by the involvement of osteopontin. Stimulation of crystal-cell adhesion impairs the opening of mitochondrial permeability transition pores (mPTP) in tubular cells and produces oxidative stress, apoptosis, and osteopontin expression. Macrophages phagocytose and digest a small amount of crystals, but many crystals aggregate into a mass containing osteopontin and epithelial cell debris and are excreted into the renal tubular lumen, becoming nuclei of urinary stones. This biomolecular mechanism is similar to atherosclerotic calcification. Based on these findings, new preventive treatments have been developed. Dietary control such as low-cholesterol intake and the ingestion of antioxidative foods and vegetables have successfully reduced the 5-year recurrence rate. Osteopontin antibodies and cyclosporine A, which blocks the opening of mPTP, have markedly inhibited the expression of osteopontin and urinary stone formation in animal models.

Pathological classification and molecular genetics of meningiomas

Meningiomas are extremely common adult brain tumors originating from meningeal coverings of the brain and spinal cord. While most are slowly growing Word Health organization (WHO) grade I tumors, rare variants (clear cell, chordoid, papillary, and rhabdoid), as well as brain invasive (WHO grade II), atypical (WHO grade II), and anaplastic (WHO grade III) meningiomas are considerably more aggressive. This review summarizes the histopathological and genetic features of meningiomas, including differential diagnosis, pitfalls, and grading challenges. Early stages of meningioma tumorigenesis are closely linked to inactivation of one or more members of the 4.1 superfamily, including the neurofibromatosis type 2 (NF2) and 4.1B (DAL-1) genes, which interact with the 14-3-3 protein family. Other chromosome 22q genes implicated include BAM22, BCR (breakpoint cluster region), and TIMP-1, the last of which is implicated in higher-grade meningiomas. Atypical meningiomas also commonly show chromosomal losses of 1p, 6q, 10, 14q, and 18q, as well as multiple chromosomal gains. While most relevant genes remain unknown, two chromosome 14q candidates (MEG3 and NDRG2) have recently been identified. In addition to alterations of CDKN2A, p14(ARF), and CDKN2B tumor suppressor genes on 9p21, a contribution of the wingless (wnt) pathway with alterations of the E-cadherin and beta-catenin proteins, as well as alterations of the hedgehog signaling pathway have been implicated in anaplastic meningiomas. The integration of histopathological appearance, complex genetic/genomic data, and outcome will likely result in the identification of clinically distinct meningioma subgroups, which in turn can facilitate the development of targeted therapeutic strategies.

Role of the metastasis-promoting protein osteopontin in the tumour microenvironment

Osteopontin (OPN) is a secreted protein present in bodily fluids and tissues. It is subject to multiple post-translational modifications, including phosphorylation, glycosylation, proteolytic cleavage and crosslinking by transglutamination. Binding of OPN to integrin and CD44 receptors regulates signalling cascades that affect processes such as adhesion, migration, invasion, chemotaxis and cell survival. A variety of cells and tissues express OPN, including bone, vasculature, kidney, inflammatory cells and numerous secretory epithelia. Normal physiological roles include regulation of immune functions, vascular remodelling, wound repair and developmental processes. OPN also is expressed in many cancers, and elevated levels in patients’ tumour tissue and blood are associated with poor prognosis. Tumour growth is regulated by interactions between tumour cells and their tissue microenvironment. Within a tumour mass, OPN can be expressed by both tumour cells and cellular components of the tumour microenvironment, and both tumour and normal cells may have receptors able to bind to OPN. OPN can also be found as a component of the extracellular matrix. The functional roles of OPN in a tumour are thus complex, with OPN secreted by both tumour cells and cells in the tumour microenvironment, both of which can in turn respond to OPN. Much remains to be learned about the cross-talk between normal and tumour cells within a tumour, and the role of multiple forms of OPN in these interactions. Understanding OPN-mediated interactions within a tumour will be important for the development of therapeutic strategies to target OPN.

Bone morphogenetic protein 4 and its receptors are expressed in the leptomeninges and meningiomas and signal via the Smad pathway

The roles of bone morphogenetic proteins (BMPs) and their receptors (BMPRs) in meningioma biology are not known. In this study, frozen tissues from 26 World Health Organization Grades I to III meningiomas were analyzed by Western blot for BMP-2/4, BMPR IA, and BMPR II, and activation of downstream p-Smad1, p38 mitogen-activated protein kinase (MAPK), and p44/42 MAPK signaling molecules. Sections from 20 normal leptomeninges, 2 arachnoid cysts, and 51 meningiomas were analyzed for BMP-4 and p44/42 MAPK by immunohistochemistry. Primary meningioma cultures from 11 meningiomas were treated with BMP-4 and evaluated for cell proliferation and signaling pathway activation. Conditioned media from 7 cultures were analyzed for BMP-4 by ELISA. Bone morphogenetic protein 4 was variably detected in adult leptomeninges but was detected in 89% or 84% of Grade I meningiomas and in 60% of Grade II meningiomas by Western blot and immunohistochemistry, respectively. Bone morphogenetic protein receptors IA and II were detected in leptomeninges and in all meningiomas studied, and activated Smad1 was detected in all meningiomas studied. Bone morphogenetic protein 4 stimulated meningioma cell proliferation and phosphorylation/activation of Smad1 but not p38 MAPK or p44/42 MAPK in vitro, and it was detected in conditioned media from 4 of 7 cultures. These findings suggest that BMP-4 and BMPRs may play autocrine/paracrine roles and interact with other transforming growth factor-beta superfamily members in regulating meningioma growth and differentiation.

The role of osteopontin in tumor progression and metastasis in breast cancer

The use of cancer biomarkers to anticipate the outlines of disease has been an emerging issue, especially as cancer treatment has made such positive steps in the last few years. Progress in the development of consistent malignancy markers is imminent because advances in genomics and bioinformatics have allowed the examination of immense amounts of data. Osteopontin is a phosphorylated glycoprotein secreted by activated macrophages, leukocytes, and activated T lymphocytes, and is present in extracellular fluids, at sites of inflammation, and in the extracellular matrix of mineralized tissues. Several physiologic roles have been attributed to osteopontin, i.e., in inflammation and immune function, in mineralized tissues, in vascular tissue, and in kidney. Osteopontin interacts with a variety of cell surface receptors, including several integrins and CD44. Binding of osteopontin to these cell surface receptors stimulates cell adhesion, migration, and specific signaling functions. Overexpression of osteopontin has been found in a variety of cancers, including breast cancer, lung cancer, colorectal cancer, stomach cancer, ovarian cancer, and melanoma. Moreover, osteopontin is present in elevated levels in the blood and plasma of some patients with metastatic cancers. Therefore, suppression of the action of osteopontin may confer significant therapeutic activity, and several strategies for bringing about this suppression have been identified. This review looks at the recent advances in understanding the possible mechanisms by which osteopontin may contribute functionally to malignancy, particularly in breast cancer. Furthermore, the measurement of osteopontin in the blood or tumors of patients with cancer, as a way of providing valuable prognostic information, will be discussed based on emerging clinical data.

Mucinous carcinoma of breast with abundant psammoma bodies in fine-needle aspiration cytology: A case report

Fine-needle aspiration (FNA) cytology plays an important role in the diagnosis of various pathologic conditions in the breast. Microcalcification can be observed in benign and malignant breast lesions, but psammoma bodies (PBs) are rarely reported in breast lesions and are a feature of papillary neoplasms. However, we have observed PBs in large numbers in a mucinous carcinoma of breast, which is not previously reported in FNA of breast lesions. A 65-yr-old postmenopausal woman underwent FNA of a palpable mass. The aspirate revealed mucinous carcinoma cells associated with plenty of PBs. This case report of mucinous carcinoma of the breast with abundant PBs highlights the cytodiagnostic pattern of the lesion and formation of PBs.

Presence of nanobacteria in psammoma bodies of ovarian cancer: evidence for pathogenetic role in intratumoral biomineralization

AIMS

The presence of laminated, calcified extracellular debris known as psammoma bodies is a well-known histomorphological feature of ovarian adenocarcinomas and other human malignancies. Biomineralization has recently been found to be associated with a group of extremely small Gram-negative bacteria capable of precipitating calcium salts. The aim of the present study was to evaluate a possible pathogenic link between the development of psammoma bodies and nanobacteria infection.

MATERIAL AND RESULTS

Immunohistochemical staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to analyse nanobacterial protein and gene expression in eight psammona body-containing adenocarcinomas and in 10 malignant ovarian tumours without signs of biomineralization. Nanobacterial proteins were detected in eight out of eight (100%) psammoma-positive tumour samples. Conversely, none of the 10 psammoma-negative tissues (0%) was positive for nanobacterial antigens. Furthermore, nanobacterial mRNA was detectable in all of the four tissues (100%) that contained psammoma bodies, but was absent in all 10 ovarian cystadenocarcinomas (0%) that were psammoma negative.

CONCLUSIONS

We found a 100% concordance between the expression of nanobacteria and the presence of psammoma bodies in malignant ovarian tumours. Several lines of evidence suggest the involvement of these organisms in the process of biomineralization. We therefore conclude that nanobacterial infection of malignant ovarian tissue contributes to mechanisms leading to the formation of calcified deposits known as psammoma bodies.

Gene expression profiling of differentiated thyroid neoplasms: diagnostic and clinical implications

PURPOSE

The purpose of this research was to identify novel genes that can be targeted as diagnostic and clinical markers of differentiated thyroid tumors.

EXPERIMENTAL DESIGN

Gene expression analysis using microarray platform was performed on 6 pathologically normal thyroid samples and 12 primary follicular and papillary thyroid neoplasms. Microarrays containing probes for 5,760 human full-length cDNAs were used for hybridization with total RNA from normal and tumor thyroid samples labeled with Cy3-dUTP and Cy5-dUTP, respectively. Scanned array images were recorded, and data analysis was performed. Selected sets of differentially expressed genes were analyzed using quantitative real-time reverse transcription-PCR for verification.

RESULTS

We identified 155 genes that differentiate histologically normal thyroid tissues from benign and malignant thyroid neoplasms. Of these 75 genes were differentiated between follicular neoplasms (adenoma and carcinoma) and the follicular variant of papillary carcinoma. Purely follicular neoplasms (adenomas and carcinomas) shared many genetic profiles, and only 43 genes were distinctly different between these tumors. Hierarchical cluster analysis also differentiated conventional papillary carcinoma from its follicular variant and follicular tumors. The differentially expressed genes were composed of members of cell differentiation, adhesion, immune response, and proliferation associated pathways. Quantitative real-time reverse transcription-PCR analysis of selected genes corroborated the microarray expression results.

CONCLUSIONS

Our study show the following: (1) differences in gene expression between tumor and nontumor bearing normal thyroid tissue can be identified, (2) a set of genes differentiate follicular neoplasm from follicular variant of papillary carcinoma, (3) follicular adenoma and carcinoma share many of the differentiated genes, and (4) gene expression differences identify conventional papillary carcinoma from the follicular variant.

Microarray‐based gene expression profiling of benign, atypical and anaplastic meningiomas identifies novel genes associated with meningioma progression

To identify gene expression profiles associated with human meningiomas of different World Health Organization (WHO) malignancy grades, we analyzed 30 tumors (13 benign meningiomas, WHO grade I; 12 atypical meningiomas, WHO grade II; 5 anaplastic meningiomas, WHO grade III) for the expression of 2,600 genes using cDNA-microarray technology. Receiver operator curve (ROC) analysis with a cutoff value of 45% selection probability identified 37 genes with decreased and 27 genes with increased expression in atypical and anaplastic meningiomas, compared to benign meningiomas. Supervised classification of the tumors did not reveal specific expression patterns representative of each WHO grade. However, anaplastic meningiomas could be distinguished from benign meningiomas by differential expression of a distinct set of genes, including several ones associated with cell cycle regulation and proliferation. Investigation of potential correlations between microarray expression data and genomic aberrations, detected by comparative genomic hybridization (CGH), demonstrated that losses on chromosomes 10 and 14 were associated with distinct expression profiles, including increased expression of several genes related to the insulin-like growth factor (IGF) (IGF2, IGFBP3 and AKT3) or wingless (WNT) (CTNNB1, CDK5R1, ENC1 and CCND1) pathways. Taken together, our microarray-based expression profiling revealed interesting novel candidate genes and pathways that may contribute to meningioma progression.

Macrophages at the skeletal tissue-device interface of loosened prosthetic devices express bone-related genes and their products

Aseptic loosening of prosthetic arthroplasty is the most common reason for implant failure in adult orthopaedic reconstruction. At the interface of aseptic loosened prostheses, there is an abundance of particle-activated macrophages and other inflammatory cells. The role of these particle-laden macrophages in the osteogenic arm of the remodeling skeleton in this pathological condition is poorly understood. Molecular signaling by mesenchymal cells and mononuclear inflammatory cells residing in the interfacial tissues between bone and cement or prosthetic material of aseptically loosened joint prostheses was studied using in situ hybridization and immunohistochemical techniques. We found that a range of collagenous and noncollagenous matrix proteins, including osteopontin, osteocalcin, bone sialoprotein, and type I collagen, were produced in the periprosthetic tissue by foamy macrophages, as well as nearby osteogenic cells. The former accumulated in profusion in the three zones of interfacial tissues: pseudomembranous, fibrous, and osseous. Spindle mesenchymal cells in the fibrous zone failed to express any of the osteogenic mRNAs or proteins sought. The expression of bone-related genes and proteins by foamy macrophages at the interface of an aseptic loosened prosthesis may contribute to the disturbance of bone remodeling at this site.

Osteopontin expression in chronic pancreatitis

INTRODUCTION

Chronic pancreatitis (CP) is frequently associated with stone formation within the pancreatic duct system. The mechanism of pancreatic stone formation, however, is still unclear.

AIMS

Osteopontin expression is related to urinary stone formation and several diseases associated with calcification such as atherosclerosis, breast cancer, and meningioma. We therefore hypothesized and studied whether that osteopontin may contribute to the formation of calculi in CP.

METHODOLOGY

Twenty patients with CP who underwent elective surgery were included in the study. As controls, normal pancreas specimens were collected from five additional patients. We used reverse transcription polymerase chain reaction and reverse transcription in situ polymerase chain reaction to evaluate osteopontin mRNA expression and immunohistochemical staining to evaluate osteopontin-producing cells.

RESULTS

No expression of osteopontin was seen in normal pancreas cells. Osteopontin expression was detected in acinar or ductal cells in all 11 cases of chronic calcifying pancreatitis, whereas in 5 of 9 CP cases without pancreatic stones there was no expression of osteopontin in acinar or ductal cells. The data revealed a high incidence of osteopontin expression in chronic calcifying pancreatitis in comparison with its expression in CP without stones (p = 0.0081). Osteopontin mRNA expression was observed in chronic calcifying pancreatitis samples but not in normal pancreas tissues. Signals corresponding to osteopontin mRNA were observed in the cytoplasm of ductal cells and macrophages.

CONCLUSION

These results provide the first evidence that osteopontin may play an important role in stone formation in CP. Better understanding of the pancreatic stone formation process may lead to an effective therapeutic approach to the inhibition of pancreatic calcification associated with CP.

Gastric carcinoma with psammomatous calcification after Billroth II reconstruction: case report and literature review

A case of gastric carcinoma with psammomatous calcification arising in the remnant stomach after Billroth II reconstruction is reported. Borrmann type 1 gastric carcinoma was detected in the remnant stomach of an 82-year-old woman, who had a past history of distal partial gastrectomy for a perforated gastric ulcer, with Billroth II reconstruction at 40 years of age. Histologically, the tumor was a tubular adenocarcinoma that invaded the muscularis propria. Numerous psammoma bodies were found in the lumens of the tumor glands. Dystrophic calcification of gastric cancer is rare and psammomatous calcification of gastric cancer has only been reported in five cases previously. To our knowledge, this is the first case of gastric carcinoma with psammomatous calcification arising in the remnant stomach. We also review previously published reports regarding gastric carcinoma with psammomatous calcification.

Meningiomas of the orbit: contemporary considerations

Meningiomas are the most frequently occurring benign intracranial neoplasms. Compared with other intracranial neoplasms they grow slowly, and they are potentially amenable to a complete surgical cure. They cause neurological compromise by direct compression of adjacent neural structures. Orbital meningiomas are interesting because of their location. They can compress the optic nerve, the intraorbital contents, the contents of the superior orbital fissure, the cavernous sinus, and frontal and temporal lobes. Because of its proximity to eloquent neurological structures, this lesion often poses a formidable operative challenge. Recent advances in techniques such as preoperative embolization and new modifications to surgical approaches allow surgeons to achieve their surgery-related goals and ultimately optimum patient outcome. Preoperative embolization may be effective in reducing intraoperative blood loss and in improving intraoperative visualization of the tumor by reducing the amount of blood obscuring the field and allowing unhurried microdissection. Advances in surgical techniques allow the surgeon to gain unfettered exposure of the tumor while minimizing the manipulation of neural structures. Recent advances in technology—namely, frameless computer-assisted image guidance—assist the surgeon in the safe resection of these tumors. Image guidance is particularly useful when resecting the osseous portion of the tumor because the tissue does not shift with respect to the calibration frame. The authors discuss their experience and review the contemporary literature concerning meningiomas of the orbit and the care of patients harboring such lesions.

Salivary gland type nasopharyngeal carcinoma: a histologic, immunohistochemical, and Epstein-Barr virus study of 15 cases including a psammomatous mucoepidermoid carcinoma

Salivary gland type nasopharyngeal carcinomas (NPCs) are rare and not well characterized. Fifteen NPCs with adenocarcinomatous differentiation were studied for their histologic types, immunohistochemical features, and association with Epstein-Barr virus (EBV) by EBER in-situ hybridization (ISH) and by polymerase chain reaction (PCR) to detect latent membrane protein-1 (LMP-1) gene with formalin-fixed, paraffin-embedded tissues. Two cases of conventional NPC were included for comparison. The prevalence rate of salivary gland type NPCs was 1.3% of the total NPCs in this series. The patients consisted of 11 men and 4 women with ages ranging from 15 to 74 years (median, 50 yrs). Mucoepidermoid carcinoma was the most common type (53%) and an unusual psammomatous variant was found. Others were adenoid cystic carcinomas and various adenocarcinomas, including a papillary adenocarcinoma. A composite tumor of adenocarcinoma and undifferentiated carcinoma was also observed. The tumors were positive for AE1 and CK19 and generally negative for AE3 and CK20. Most cases were positive for epithelial membrane antigen and CA 19-9 with sporadic expression of carcinoembryonic antigen (CEA) and S-100 protein. Conventional NPC differed only in consistent immunonegativity for CA19-9 and CEA. EBV was detected by EBER ISH in 9 of 15 cases (60%) and by PCR of the LMP-1 gene in 10 of 15 cases (67%). Six of 10 LMP-1 gene-positive cases (60%) had a specific deletion of 30-base pairs (bp) of the LMP-1 gene. The result also supports the possible importance of a 30-bp deletion in conferring the oncogenecity of the LMP-1 gene. The prognosis of this series of salivary gland type NPCs was poor. Six of 13 patients with follow-up information already died of the disease with a median survival of only 1 year.

Expression of osteopontin messenger RNA by macrophages in ovarian serous papillary cystadenocarcinoma: a possible association with calcification of psammoma bodies

Calcified psammoma bodies often appear in human ovarian serous papillary cystadenocarcinoma. Osteocalcin (OC), osteonectin (ON) and osteopontin (OPN) are three members of non-collagenous bone-related proteins known to be related with mineralization of bone. To clarify possible involvement of these bone matrix proteins in the calcification of the psammoma bodies, the expression of OC, ON and OPN was analyzed by immunohistochemical and in situ hybridization studies using 15 surgical specimens. OPN protein was detected in the calcified area of the psammoma bodies which was positively stained by von Kóssa's staining, while OC and ON proteins were not. OPN protein was not detected in any cells in tissues, but OPN messenger ribonucleic acid (mRNA) was detected in CD68-positive macrophages, indicating that OPN was produced and promptly secreted by macrophages. These results suggest that OPN produced and promptly secreted by macrophages and subsequently translocated to psammoma bodies may be causally related with the calcium phosphate deposition in the psammoma bodies of the ovarian serous papillary cystadenocarcinomas.

Factor H binding to bone sialoprotein and osteopontin enables tumor cell evasion of complement-mediated attack

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 alpha(V)beta(3) 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.