Sclerostin expression in bone tumours and tumour-like lesions.

Aims: To assess the immunophenotypic and mRNA expression of sclerostin in human skeletal tissues and in a wide range of benign and malignant bone tumours and tumour-like lesions.

Methods And Results: Sclerostin expression was evaluated by immunohistochemistry and quantitative polymerase chain reaction (PCR). In lamellar and woven bone, there was strong sclerostin expression by osteocytes.

The niche component periostin is produced by cancer-associated fibroblasts, supporting growth of gastric cancer through ERK activation.

Overexpression of periostin (POSTN), an extracellular matrix protein, has been observed in several cancers. We investigated the importance of POSTN in gastric cancer. Genome-wide gene expression analysis using publicly available microarray data sets revealed significantly high POSTN expression in cancer tissues from stage II-IV gastric cancer, compared with background normal tissues.

Localized Ewing sarcoma of the tibia.

Ewing sarcoma (ES) is a high-grade malignant primary round cell tumour of bone in which there is commonly extension into extraosseous soft tissues at the time of diagnosis. This report details the clinical, radiological and pathological features of a case of ES of the tibia in which there was extensive osseous involvement but no infiltration beyond the periosteum into surrounding soft tissue. We also record the findings of one other ES case that exhibited similar behaviour.

VEGF, FLT3 ligand, PlGF and HGF can substitute for M-CSF to induce human osteoclast formation: implications for giant cell tumour pathobiology.

Giant cell tumour of bone (GCTB) is a primary bone tumour that contains numerous very large, hyper-nucleated osteoclastic giant cells. Osteoclasts form from CD14+ monocytes and macrophages in the presence of receptor activator of nuclear factor kappa B ligand (RANKL) and macrophage-colony stimulating factor (M-CSF). GCTB contains numerous growth factors, some of which have been reported to influence osteoclastogenesis and resorption.

CD14- mononuclear stromal cells support (CD14+) monocyte-osteoclast differentiation in aneurysmal bone cyst.

Aneurysmal bone cyst (ABC) is a benign osteolytic bone lesion in which there are blood-filled spaces separated by fibrous septa containing giant cells. The nature of the giant cells in this lesion and the mechanism of bone destruction in ABC is not certain. In this study, we have analysed several characteristics of mononuclear and multinucleated cells in the ABC and examined the cellular and molecular mechanisms of ABC osteolysis.

Analysis of stromal cells in osteofibrous dysplasia and adamantinoma of long bones.

Adamantinoma of long bones and osteofibrous dysplasia are rare, osteolytic primary bone tumours of uncertain origin containing areas of fibrous and fibro-osseous proliferation. We investigated the nature of the stromal cells in adamantinoma of long bones and osteofibrous dysplasia, and determined cellular and molecular mechanisms of osteolysis in these tumours. Cell culture, molecular (RT-PCR, western blot) and immunohistochemical studies on cases of adamantinoma of long bones and of osteofibrous dysplasia were undertaken to determine the expression of epithelial, osteoblast and osteoclast markers.

Podoplanin is regulated by AP-1 and promotes platelet aggregation and cell migration in osteosarcoma.

Podoplanin is a type-I transmembrane sialomucin-like protein, which is expressed in a wide range of cell types and is involved in platelet aggregation and tumor metastasis. Here, we investigated the function, regulation, and expression of podoplanin in osteosarcoma. Podoplanin expression was observed in three osteosarcoma cell lines (MG-63, HOS, and U-2 OS) with platelet aggregation-inducing ability, which was blocked by podoplanin small-interfering RNA or a neutralizing antibody.

Podoplanin expression in adamantinoma of long bones and osteofibrous dysplasia.

Adamantinoma of long bones (ALB) and osteofibrous dysplasia (OFD) are rare osteolytic bone tumours that principally arise in the tibia. Both ALB and OFD contain epithelial and stromal elements, as well as areas of fibro-osseous proliferation. We assessed expression of podoplanin, a glycoprotein found in osteocytes, in OFD and ALB as well as in fibrous dysplasia and metastatic cancer.

Delayed re-epithelialization in periostin-deficient mice during cutaneous wound healing.

Background: Matricellular proteins, including periostin, are important for tissue regeneration.

Methods And Findings: Presently we investigated the function of periostin in cutaneous wound healing by using periostin-deficient ⁻/⁻ mice. Periostin mRNA was expressed in both the epidermis and hair follicles, and periostin protein was located at the basement membrane in the hair follicles together with fibronectin and laminin γ2.

Stable knockdown of S100A4 suppresses cell migration and metastasis of osteosarcoma.

S100A4, a 10-12 kDa calcium-binding protein, plays functional roles in tumor progression and metastasis. The present study aimed to investigate the function of S100A4 in osteosarcoma (OS) metastasis, using a loss-of-function approach. Our previous expression profiling analysis revealed that S100a4 was preferentially expressed in the highly metastatic mouse OS cell line, LM8.

Lymphatic involvement in vertebral and disc pathology.

Study Design: Analysis of lymphatic vessels in childhood and adult normal and pathological vertebral bone and intervertebral disc tissue.

Objective: To determine whether lymphatic vessels are present in spinal vertebrae and intervertebral discs in normal children and adults (4-30 years) as well as in pathological lesions of the spine.

Summary Of Background Data: There is uncertainty regarding the presence or absence of lymphatic vessels in normal intervertebral discs and the role of lymphatics in the pathobiology of disc degeneration and infective, neoplastic, and other spinal pathology.

Neighbor of Brca1 gene (Nbr1) functions as a negative regulator of postnatal osteoblastic bone formation and p38 MAPK activity.

The neighbor of Brca1 gene (Nbr1) functions as an autophagy receptor involved in targeting ubiquitinated proteins for degradation. It also has a dual role as a scaffold protein to regulate growth-factor receptor and downstream signaling pathways. We show that genetic truncation of murine Nbr1 leads to an age-dependent increase in bone mass and bone mineral density through increased osteoblast differentiation and activity.

Periostin, a novel marker of intramembranous ossification, is expressed in fibrous dysplasia and in c-Fos-overexpressing bone lesions.

Fibrous dysplasia is a benign bone disease caused by a mutation in the gene for the stimulatory guanine nucleotide-binding protein Gs alpha, leading to high cyclic adenosine monophosphate levels. Histologically, fibrous dysplasia is characterized by the production of fibrous tissue accompanied by the deposition of ectopic type I collagen and other bone-associated extracellular matrix proteins, as well as by irregular woven intramembranous bone onto which type I collagen-containing Sharpey fibers are often attached. Fibrous dysplasia is also characterized by high expression of c-Fos/c-Jun, known targets for cyclic adenosine monophosphate signaling.

Periostin is expressed in pericryptal fibroblasts and cancer-associated fibroblasts in the colon.

Periostin is a unique extracellular matrix protein, deposition of which is enhanced by mechanical stress and the tissue repair process. Its significance in normal and neoplastic colon has not been fully clarified yet. Using immunohistochemistry and immunoelectron microscopy with a highly specific monoclonal antibody, periostin deposition was observed in close proximity to pericryptal fibroblasts of colonic crypts.

The platelet aggregation-inducing factor aggrus/podoplanin promotes pulmonary metastasis.

Tumor cell-induced platelet aggregation has been reported to facilitate hematogenous metastasis. Aggrus/podoplanin is a platelet aggregation-inducing factor that is up-regulated in a number of human cancers and has been implicated in tumor progression. We studied herein the role of Aggrus in tumor growth, metastasis , and survival in vivo.