Peroxiredoxin 2 is a novel autoantigen for anti-endothelial cell antibodies in systemic vasculitis

Anti-endothelial cell antibodies (AECA) have been frequently detected in systemic vasculitis, which affects blood vessels of various sizes. To understand the pathogenic roles of AECA in systemic vasculitis, we attempted to identify target antigens for AECA comprehensively by a proteomic approach. Proteins extracted from human umbilical vein endothelial cells (HUVEC) were separated by two-dimensional electrophoresis, and Western blotting was subsequently conducted using sera from patients with systemic vasculitis. As a result, 53 autoantigenic protein spots for AECA were detected, nine of which were identified by mass spectrometry. One of the identified proteins was peroxiredoxin 2 (Prx2), an anti-oxidant enzyme. Frequency of anti-Prx2 autoantibodies, measured by enzyme-linked immunosorbent assay (ELISA), was significantly higher in systemic vasculitis (60%) compared to those in collagen diseases without clinical vasculitis (7%, P < 0·01) and healthy individuals (0%, P < 0·01). Further, the titres changed in parallel with the disease activity during time-courses. The presence of anti-Prx2 autoantibodies correlated significantly with elevation of serum d-dimers and thrombin-antithrombin complex (P < 0·05). Immunocytochemical analysis revealed that live endothelial cells expressed Prx2 on their surface. Interestingly, stimulation of HUVEC with rabbit anti-Prx2 antibodies increased secretion of interleukin (IL)-6, IL-1β, IL-1ra, growth regulated oncogene (GRO)-α, granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), IL-8 and monocyte chemoattractant protein (MCP)-1 more than twofold compared to that of with rabbit immunoglobulin (Ig)G. Taken together, our data suggest that anti-Prx2 autoantibodies would be a useful marker for systemic vasculitis and would be involved in the inflammatory processes of systemic vasculitis.

A metabolic aspect of osteoarthritis: lipid as a possible contributor to the pathogenesis of cartilage degradation

Osteoarthritis (OA) is considered to be linked to obesity and body fat mass. Recent investigations, however, are aimed at clarifying the roles of adipose tissue-derived proteins and a wide variety of lipid mediators, including fatty acids, sphingolipids, and eicosanoids, in cartilage degradation in OA, in addition to the effects body weight itself. Here, we review recent progress in studies of OA, focusing on the potential role of lipid mediators in articular cartilage and introducing the concept that "OA is a metabolic disease" in which lipids essentially contribute to the pathophysiology of cartilage degradation.

Development and characteristics of pannus-like soft tissue in osteoarthritic articular surface in rat osteoarthritis model

OBJECTIVES

Pannus is invasive granulation tissue found on the articular cartilage having rheumatoid arthritis (RA). However, pannus-like tissue has also been found in osteoarthritis (OA). Our previous study showed that pannus-like tissue in OA (OA pannus) was frequently found in human OA samples. The purpose of the study is to investigate the development and the characteristics of OA pannus in a rat OA model.

DESIGN

Ligaments of the knee joint were transected in Wister rats to induce OA. The knee joints were removed at weeks 1, 2, 4 and 6, and subjected to histological study. Samples were stained with hematoxylin and eosin (HE), Safranin-O and immuno-stained for vimentin, CD34, type II collagen and MMP-3. The whole knee joint of OA rats was implanted in SCID mice and kept for a further 3 weeks. Then the histological findings were evaluated in HE sections.

RESULT

OA pannus appeared at week 2 and extend over the articular surface. OA pannus cells were positive for vimentin and/or CD34. At week 6, a part of articular surface was restored with matrix. OA pannus cells expressed MMP-3 as well as type II collagen. Histological study of rat OA knees implanted in SCID mice showed that OA pannus cells filled the joint space and invaded articular cartilage.

CONCLUSIONS

The presence of OA pannus was found in a rat OA model and its features were similar to those in human OA. OA pannus had both catabolic and reparative features, and the latter feature were speculated to be dominant in the later phase of the disease under a certain environmental condition.

The potential role of vascular endothelial growth factor (VEGF) in cartilage: how the angiogenic factor could be involved in the pathogenesis of osteoarthritis?

Although adult human cartilage is physiologically avascular tissue, angiogenesis can be observed during the process of endochondral bone development. Inflammation in articular joints can also lead to neovascularization in cartilage. In such conditions, the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF), has been shown to play a key role, controlling not only angiogenesis but also chondrocyte metabolism. Here we review recent research findings concerning the potential role of VEGF in cartilage, focusing in particular on its possible involvement in the pathogenesis of osteoarthritis.

Tryptase enhances release of vascular endothelial growth factor from human osteoarthritic chondrocytes

OBJECTIVE

A contribution of mast cells and its mediators in the pathogenesis of arthritis has been postulated. We aimed to clarify the role of mast cell-derived serine protease tryptase and proteinase activated receptor (PAR)-2-mediated signaling in chondrocytes.

METHODS

Human articular cartilage specimens were obtained from patients with osteoarthritis (OA), rheumatoid arthritis (RA) and with traumatic fracture without arthritis (PT; as controls) who underwent joint surgery. Isolated chondrocytes were cultured in vitro by monolayer, and confluent cells were incubated with recombinant human lung Beta tryptase or with a PAR-2 agonist peptide. The secreted level of vascular endothelial growth factor (VEGF) in culture supernatant was measured using commercially available ELISA kits, and expression of VEGF mRNA was analyzed using real-time PCR.

RESULTS

The tryptase-stimulated chondrocytes from OA or RA, but not from PT patients, produced significantly higher amount of VEGF in their supernatants. The response was blocked by a G-protein receptor inhibitor pertussis toxin, however, was not reproduced by incubation of cells with the PAR-2 agonist, suggesting a presence of non-PAR-2 dependent signals for the VEGF induction. In addition, actinomycin D and cycloheximide did not exert significant inhibition, indicating a regulation of VEGF release by tryptase.

CONCLUSION

The inflammatory mediator, mast cell-derived protease tryptase may modulate chondrocyte metabolism through induction of VEGF release.

Positron emission tomography with 18F-FDG in osteoarthritic knee

OBJECTIVES

To evaluate osteoarthritis (OA) of the knee using positron emission tomography (PET) with 2-(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) as a tracer.

MATERIALS AND METHODS

Fifteen patients with medial-type knee OA and three healthy subjects were enrolled in the study. After clinical examination and conventional radiography, (18)F-FDG PET and magnetic resonance imaging (MRI) were performed. (18)F-FDG uptake was quantified as a standardized uptake value (SUV) and the localization of (18)F-FDG uptake was identified using fusion images created with MRI scans.

RESULTS

(18)F-FDG generally accumulated in periarticular lesions and was absent in the articular cartilage. SUVs of the whole knee were higher in OA than in controls, and those in the medial condyle were higher than in the lateral condyle in OA. Prominent (18)F-FDG uptake was found in the intercondylar notch in OA and extended along the posterior cruciate ligament (PCL) in some cases. Periosteophytic accumulation was found in one-half of cases with definite osteophytes. Accumulation was also found in subchondral lesions and bone marrow, which corresponded with bone edema diagnosed by MRI. No significant correlation was found between SUV and clinical manifestations.

CONCLUSIONS

(18)F-FDG uptake was upregulated in OA and generally accumulated in periarticular lesions. Increased uptake was found in the intercondylar notch extending along the PCL, periosteophytic lesions, and bone marrow. These results provide in vivo pathognomonic insights into OA.

Effects of celecoxib on human chondrocytes--enhanced production of chemokines

OBJECTIVE

The purpose of this study was to examine the effects of a selective cyclooxigenase-2 (COX-2) inhibitor (celecoxib) comparing diclofenac.

METHODS

Using chondrocytes derived from cartilage of non-arthritic (NA) subjects or patients with osteoarthritis (OA) or rheumatoid arthritis (RA), we examined the effects of celecoxib on incorporation of 3H-thymidine and 35S-sulfate, apoptosis, and production of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, and regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1a and nitric oxide (NO).

RESULTS

Celecoxib and diclofenac tended to reduce 3H-tymidine incorporation of chondrocytes. Celecoxib induced apoptosis in a dose-dependent manner, but to a lesser degree than diclofenac. Celecoxib inhibited proteoglycan synthesis (indicated by 35S-sulfate incorporation) in NA chondrocytes, but not in OA and RA chondrocytes. Celecoxib increased interleukin-1 (IL-1)-induced production of RANTES and MIP-1alpha by chondrocytes and decreased IL-1-induced NO production by chondrocytes, whereas it did not affect MMP production.

CONCLUSION

Celecoxib had both beneficial and adverse effects on chondrocytes. RA, OA and NA chondrocytes showed different responses. Interestingly, celecoxib enhanced the production of chemokines.

Expression of proteinase-activated receptors (PAR)-2 in articular chondrocytes is modulated by IL-1beta, TNF-alpha and TGF-beta

OBJECTIVE

To investigate the modulation of expression of proteinase-activated receptor-2 (PAR-2) in articular chondrocytes by inflammatory cytokines.

DESIGN

Articular synovium and cartilage tissues were collected from eight patients with osteoarthritis (OA), and three patients without arthropathy ("normal"). Chondrocytes were stimulated with interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha or transforming growth factor (TGF)-beta1. The expression of PAR-2 was detected using reverse transcriptase-polymerase chain reaction (PCR), Western blotting and immunofluorescence. Quantitative PCR was performed to assess the expression levels of PAR-2 messenger RNA (mRNA).

RESULTS

The expression of PAR-2 mRNA was demonstrated in both OA and normal chondrocytes as well as in synovial fibroblasts. However, the level of PAR-2 in OA chondrocytes was much higher than in normal chondrocytes. Long-term culture revealed that PAR-2 mRNA expression was maintained up to three passages in OA but not in normal chondrocytes. IL-1beta and TNF-alpha both upregulated PAR-2 expression in normal and OA chondrocytes. In contrast, TGF-beta1 significantly decreased expression of PAR-2 in OA chondrocytes but increased PAR-2 in normal chondrocytes.

CONCLUSIONS

Overexpression of PAR-2 in OA chondrocytes is upregulated by proinflammatory cytokines IL-1beta and TNF-alpha, and down-regulated by regulatory cytokine TGF-beta1. PAR-2 may be involved in the pathogenesis of OA.

The role of subchondral bone resorption pits in osteoarthritis: MMP production by cells derived from bone marrow

OBJECTIVE

The vascular invasion of bone marrow tissue into the subchondral plate is often observed in articular cartilage and we named it the subchondral bone absorption pit; however, its implication in the pathogenesis of osteoarthritis (OA) has been poorly understood. The purpose of this study was to evaluate its characteristics and roles in osteoarthritic conditions.

METHODS

Articular cartilage specimens from 11 patients with medial type knee OA and 7 non-arthritic cadavers were analyzed with HE staining. OA sections were stained with safranin-O, TRAP (tartrate resistant acid phosphatase) and immunostained with anti-MMP-1, MMP-3, MMP-13, vitronectin receptor (VNR)-alpha chain, vimentin and bone morphogenic protein (BMP) 2/4 antibodies.

RESULTS

Subchondral bone resorption pits were classified according to the extent of invasion: pits with bone marrow tissue were located within uncalcified cartilage below the tidemark in grade I and invaded beyond the tidemark in grade II, while no invasion was seen in grade 0. Grade II pits were dominant in OA compared to non-arthritic joints, especially medial condyles. Proteoglycan detected with safranin-O staining was lost around the tip of grade II pits and the density of pits was related to the modified Mankin Score. Cells in pits expressed vimentin, MMP-1, MMP-3 and MMP-13. Some polynuclear cells co-expressed VNR-alpha chain and MMP-13, whereas pits showed reparative features expressing BMP.

CONCLUSION

These results suggest that subchondral bone resorption pits contribute to cartilage degradation by expressing matrix metalloproteinases in OA.

Implication of interleukin 18 in production of matrix metalloproteinases in articular chondrocytes in arthritis: direct effect on chondrocytes may not be pivotal

OBJECTIVE

To clarify the effect of interleukin (IL) 18 on cartilage degeneration by studying the profile of IL18 receptor (IL18R) on chondrocytes and the direct effect of IL18 on production of matrix metalloproteinases (MMPs), aggrecanases, and tissue inhibitors of metalloproteinases (TIMPs) in articular chondrocytes.

METHODS

Monolayer cultured human articular chondrocytes were isolated from non-arthritic subjects and patients with rheumatoid arthritis or osteoarthritis. Gene expression of IL18, IL18Ralpha, IL18Rbeta, MMPs, and aggrecanases was detected by RT-PCR. Protein levels of IL18Ralpha were analysed by flow cytometry. Protein levels of IL18, MMPs, and TIMPs were measured by ELISA. Aggrecanase-2 mRNA expression was quantitatively analysed by real time RT-PCR. Protein levels of signalling molecules were assayed by western blotting.

RESULTS

IL18 mRNA was constitutively expressed in chondrocytes, and was enhanced by IL1beta stimulation. Flow cytometric analysis showed that IL1beta, tumour necrosis factor alpha, and IL18 up regulated IL18Ralpha expression levels. The level of IL18Rbeta mRNA was much lower than that of IL18Ralpha, and was slightly up regulated by IL1beta. In chondrocytes responding to IL18, IL18 (1-100 ng/ml) slightly increased the production of MMP-1, MMP-3, and MMP-13, which was blocked by NF-kappaB inhibitor and p38 mitogen activated protein kinase inhibitor. IL18 up regulated mRNA expression of aggrecanase-2, but not aggrecanase-1. IL18 also slightly stimulated TIMP-1 production?through extracellular signal regulated kinase activation.

CONCLUSION

IL18 induces production of MMPs from chondrocytes in inflammatory arthritis. Although the direct effect of IL18 on chondrocytes may not be pivotal for the induction of cartilage degeneration, IL18 seems to play some part in the degradation of articular cartilage in arthritis.

Interleukin (IL) 18 stimulates osteoclast formation through synovial T cells in rheumatoid arthritis: comparison with IL1 beta and tumour necrosis factor alpha

OBJECTIVE

To determine whether IL18 has any indirect effects on osteoclastogenesis mediated by T cells in RA synovium, and compare its effects with those of IL1 beta and TNF alpha.

METHODS

Resting T cells were isolated from peripheral blood of healthy donors, and stimulated with 2 microg/ml phytohaemagglutinin (PHA) and 0.5 ng/ml IL2 for 24 hours. Synovial T cells were isolated from RA synovial tissue. The levels of soluble receptor activator of the NF-kappa B ligand (RANKL), osteoprotegerin (OPG), IFN gamma, M-CSF, and GM-CSF were determined by ELISA. Membrane bound RANKL expression was analysed by flow cytometry. Commercially available human osteoclast precursors were cocultured with T cells to induce osteoclast formation, which was determined with tartrate resistant acid phosphatase staining and pit formation assay.

RESULTS

In PHA prestimulated T cells or RA synovial T cells, IL18, IL1 beta, or TNFalpha increased soluble RANKL production and membrane bound RANKL expression in a dose dependent manner. IL18, IL1 beta, and TNF alpha did not induce M-CSF, GM-CSF, IFN gamma, or OPG production in PHA prestimulated T cells or RA synovial T cells. IL18 increased the number of osteoclasts and bone resorption area on dentine slices in the coculture of human osteoclast precursors with PHA prestimulated T cells or RA synovial T cells; its ability was equivalent to that of IL1 beta, but less potent than that of TNF alpha. In the coculture system, OPG completely blocked osteoclast induction by IL18 or IL1 beta, and greatly inhibited induction by TNF alpha.

CONCLUSION

IL18, IL1 beta, or TNF alpha can indirectly stimulate osteoclast formation through up regulation of RANKL production from T cells in RA synovitis; IL18 is as effective as IL1 beta, but less potent than TNF alpha.

Telomerized presenescent osteoblasts prevent bone mass loss in vivo

Previously, we showed that human osteoblasts expressing the human telomerase reverse transcriptase (hTERT) gene exhibited specific survival advantages--the result of breaching the replicative senescence barrier and maintaining the phenotypic and functional properties of primary osteoblasts in vitro over the total replicative capacity of primary osteoblasts. We postulated that rejuvenated osteoblasts may have a potential to correct bone loss or osteopenia in age-related osteoporotic diseases. In the present study, we studied whether telomerized presenescent osteoblasts prevent bone mass loss in vivo. After obtaining the informed consent from a patient with osteoarthritis who underwent the arthroplastic knee surgery, osteoblastic cells were isolated from donor bone sample. We transfected the gene encoding hTERT into human osteoblastic cells. Human bone fragments from a donor were incubated with human hTERT-transfected presenescent (in vitro aged) osteoblasts or mock-transfected presenescent osteoblasts in culture medium containing Matrigel. We subcutaneously implanted human bone fragments with telomerized presenescent osteoblasts or primary presenescent osteoblasts as three-dimensional Matrigel xenografts in severe combined immunodeficiency (SCID) mice (each group: six mice) and analyzed the grafts at 6 weeks after implantation. We also determined whether telomerized osteoblasts affect the bone-forming capacity in vivo, using a well-established mouse transplantation model in which ceramic hydroxyapatite/tricalcium phosphate particles are used as carrier vehicle. Telomerized presenescent osteoblasts were rejuvenated, and maintained the functional properties of young osteoblasts in vitro. Bone mineral content (BMC) and bone mineral density (BMD) were measured by ash weight and dual-energy X-ray absorptiometry, respectively. Whereas BMC and BMD of human bone fragments, which were inoculated with aged osteoblasts in SCID mice, decreased with time, telomerized presenescent osteoblasts maintained the BMC and BMD of human bone fragments, indicating that telomerized and rejuvenated osteoblasts may be functional to prevent bone mass loss in vivo. In xenogenic transplants, telomerized osteoblasts generated more bone tissue with lamellar bone structure and cellular components, than did control osteoblasts. These findings suggest that telomerized/rejuvenated presenescent osteoblasts may be used in the development of tissue engineering or cell-based therapy for bone regeneration and repair.

Corticosteroid treatment induces chondrocyte apoptosis in an experimental arthritis model and in chondrocyte cultures

OBJECT

In order to examine the mechanisms involved in steroid-induced arthropathy after intra-articular corticosteroid injection, a histological examination was performed in vivo using severe combined immunodeficiency (SCID) mice that were implanted with human articular cartilage into the back (SCID/hu model). In addition, the effect of corticosteroids on chondrocyte apoptosis was evaluated in vitro using cultured human chondrocytes.

METHOD

Human articular cartilage was obtained during knee surgery and implanted subcutaneously into the backs of SCID mice. One month later, weekly injections of corticosteroid (hydrocortisone acatate: 1 mg/0.2 ml, triamcinolone acetonide: 0.2 mg/0.2 ml, dexamethasone acetate: 0.1 mg/0.2 ml) in the subcutaneous cavity around the grafted cartilage in SCID mice were initiated. After six weeks of treatment, the grafted cartilage pieces were removed from the SCID mice and examined histologically. Chondrocyte apoptosis after corticosteroid treatment was also investigated using cultured human chondrocytes.

RESULT

In the corticosteroid treated, grafted articular cartilage, apoptotic chondrocytes were apparent in the superficial and middle layers of cartilage. But a reduced intensity of Safranin O staining was not remarkable. In the cultured chondrocytes, apoptotic changes were also observed after corticosteroid treatment.

CONCLUSION

Corticosteroid treatment induces chondrocyte apoptosis and it may be important to understand the steroid-induced arthropathy.

The role of TNF-alpha in the pathogenesis of inflammation and joint destruction in rheumatoid arthritis (RA): a study using a human RA/SCID mouse chimera

OBJECTIVE

In order to elucidate which cytokine preferentially stimulates the synovium in patients with rheumatoid arthritis (RA), we investigated the roles of tumour necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) using SCID mice engrafted with human RA tissue (SCID-HuRAg).

METHODS

The SCID-HuRAg mice were prepared according to our previously described method. First, SCID-HuRAg mice were treated with chimeric anti-TNF-alpha monoclonal antibody (mAb, 100 microg/mouse) and histological changes were examined 4 weeks after the initial treatment. Secondly, a total of 100 microg of recombinant TNF-alpha or IL-6 (0.6 microg/h) was administered daily to mice using an osmium pump. The histological changes and serum cytokine levels were examined 4 weeks after the initial administration. Human immunoglobulin G (IgG) was administered to mice as a control.

RESULTS

Synovial inflammatory cells were significantly decreased after the anti-TNF-alpha mAb treatment; conversely, the degree of synovial inflammation was significantly exacerbated by TNF-alpha administration. The levels of both IL-6 and TNF-alpha in sera were significantly increased by recombinant TNF-alpha administration, while TNF-alpha levels were unchanged by IL-6 administration. This suggests that TNF-alpha controls IL-6 production. Despite the profound changes in inflammation, we found no effects on bone and no articular cartilage damage was produced by TNF-alpha.

CONCLUSION

This study provides strong evidence that TNF-alpha is a key molecule in the control of the inflammatory changes that occur in the RA synovium. In addition, TNF-alpha regulates IL-6 production. However, other inflammatory pathways independent of TNF-alpha may contribute to the bone and cartilage damage seen in RA.

Reconstituting telomerase activity using the telomerase catalytic subunit prevents the telomere shorting and replicative senescence in human osteoblasts

The rate of bone formation is largely determined by the number of osteoblasts, which in turn is determined by the rate of replication of progenitors and the life span of mature cells, reflecting the timing of death by apoptosis. However, the exact age-dependent changes of the cellular activity, replicative potential, and life span of osteoblasts have not been investigated to date. Here, we present evidence that the cellular activity, telomere lengths, and replicative life span of osteoblastic cells obtained from juxta-articular bone marrow gradually decrease with the advance of donor age. Recently, telomerase reverse transcriptase (hTERT) has been identified as a human telomerase catalytic subunit. We transfected the gene encoding hTERT into telomerase-negative human osteoblastic cells from donors and osteoblastic cell strain NHOst 54881 cells and showed that expression of hTERT induces telomerase activity in these osteoblastic cells. In contrast to telomerase-negative control cells, which exhibited telomere shortening and senescence after 10-15 population doublings, telomerase-expressing osteoblastic cells had elongated telomere lengths and showed continued alkaline phosphatase activity and procollagen I C-terminal propeptide (PICP) secretion for more than 30 population doublings. These results indicate that osteoblasts with forced expression of hTERT may be used in cell-based therapies such as ex vivo gene therapy, tissue engineering, and transplantation of osteoblasts to correct bone loss or osteopenia in age-related osteoporotic diseases.

Methotrexate inhibits rheumatoid synovitis by inducing apoptosis

OBJECTIVE

To clarify the pharmacological action of methotrexate (MTX) on the synovium of patients with rheumatoid arthritis (RA) using severe combined immunodeficient (SCID) mice in which human RA synovial tissue had been grafted (SCID-HuRAg).

METHODS

One month after engraftment of human RA tissue into SCID mice, MTX (0.3 mg/kg) was administered orally, then the appearance of apoptosis in the grafted tissue was examined by TdT mediated dUTP nick end labeling (TUNEL) staining and electron microscopy at various time points after MTX administration. In cultured synovial cells, synovial apoptotic changes after MTX treatment were studied by agarose gel electrophoresis and flow cytometric analysis. To compare the histological changes induced by MTX with those induced by other disease modifying antirheumatic drugs (DMARD) and a nonsteroidal antiinflammatory drug, histological examination of the grafted synovial tissues from SCID-HuRAg mice was conducted after 4 weeks of oral administration of MTX (0.3 mg/kg/week), salazosulfapyridine (30 mg/kg/day), auranofin (0.2 mg/kg/day), bucillamine (10 mg/kg/day), or indomethacin (2 mg/kg/day).

RESULTS

A significant decrease in the number of inflammatory cells was observed in the grafted synovial tissue of MTX treated SCID-HuRAg. A similar antiinflammatory effect was not observed with the other DMARD. Induction of apoptosis was noted with MTX treatment but not with the others. The pro-apoptotic effect of MTX was also observed in synovial cell cultures.

CONCLUSION

MTX induces apoptosis in RA synovium that, in turn, may contribute to its antiinflammatory effect on RA synovitis.

Effects of vascular endothelial growth factor and E-selectin on angiogenesis in the murine metastatic RCT sarcoma

The relationship between vascular endothelial growth factor (VEGF) and induction of angiogenesis in high-metastatic RCT(+) or low-metastatic RCT(-) clones of the poorly differentiated murine RCT sarcoma was investigated. The association with E-selectin in VEGF-induced angiogenesis was also evaluated. RCT(+) cells produced significantly larger amounts of VEGF than RCT(-) cells. In a tube formation assay with murine lung microvascular endothelial (MLE) cells, conditioned medium from RCT(+) cells showed a significantly greater effect on tube formation than that from RCT(-) cells. Induction of tube formation was suppressed by anti-mouse VEGF monoclonal antibody. Furthermore, anti-mouse E-selectin monoclonal antibody suppressed the tube formation induced by recombinant mouse VEGF. In a flow-cytometric analysis, the expression of E-selectin on MLE cells was upregulated after pretreatment with conditioned medium from RCT(+) and RCT(-) cells. Conditioned medium from RCT(+) cells induced a higher expression of E-selectin compared to medium from RCT(-) cells. Anti-VEGF monoclonal antibody prevented the upregulation of E-selectin by the RCT cell-conditioned medium. These findings suggest that E-selectin plays an important role in the angiogenesis induced by VEGF. VEGF derived from tumor cells may enhance angiogenesis by upregulating the expression of E-selectin on vascular endothelial cells.

Concentration of vascular endothelial growth factor in the tumour tissue as a prognostic factor of soft tissue sarcomas

Previous studies have shown that the prognosis of patients who have tumours with high microvessel density (MVD) is worse than that of patients who have a lower density in a variety of cancers. In this study, we investigated the clinical relevance of neovascularity assessed by MVD and the concentration of vascular endothelial growth factor (VEGF) in the tumour tissue of patients with soft tissue sarcoma in comparison with major clinicohistologic parameters by univariate and multivariate analysis. In 115 patients with soft tissue sarcoma, MVD was measured by counting vessels stained with factor VIII antibody. The concentration of VEGF in the tumour tissue was determined by enzyme-linked immunosorbent assay. These parameters were then compared with disease outcome. The concentration of VEGF in the tumour tissue, but not MVD, was found to be correlated with disease outcome in patients with soft tissue, sarcoma. VEGF concentration in the tumour tissue showed a relationship with the clinical stage and histologic grade of the tumour. There was no significant difference in the levels of tissue VEGF concentration and MVD among soft tissue sarcomas classified according to histologic type. The level of tissue VEGF concentration in patients who had subsequent local recurrence and metastasis were significantly higher than the respective values in patients who did not have such disease outcome. No significant correlation existed between MVD and the concentration of VEGF in the tumour tissue. Univariate analysis showed that a high tissue VEGF concentration was associated with poor overall survival of the patient and a greater probability that local recurrence and metastasis had occurred. Multivariate analysis revealed that the tissue concentration of VEGF is an independent prognostic factor for the disease outcome of patients with soft tissue sarcoma. VEGF concentration in the tumour tissue, but not MVD, is an additional prognostic parameter for disease outcome in patients with soft tissue sarcoma, regardless of histologic type.

[Relationship between periarticular osteoporosis and osteoblast senescence in patients with rheumatoid arthritis]

The rate of bone formation is largely determined by the number of osteoblasts, which in turn is determined by the rate of replication of progenitors and the life-span of mature cells, reflecting the timing of death by apoptosis. However, the exact age-dependent changes of the cellular activity, replicative potential and life-span of osteoblasts have not so far been investigated to date. Here we present evidence that the cellular activity, telomere lengths and replicative life-span of osteoblastic cells obtained from juxta-articular bone marrow gradually decrease with the advance of donor age in patients with rheumatoid arthritis or osteoarthritis. Recently, human telomerase reverse transcriptase (hTERT) has been identified as a human teromerase catalytic subunit. We postulate that an expansion of the life-span of osteoblasts and their maintenance as differentiated bone matrix-producing cells may allow for autologus or allogenic cell and gene therapy in bone and joint diseases including osteoporosis. We therefore transfected human osteoblasts with a vector expressing hTERT cDNA, and investigated whether the replicative life-span can be expanded by the introduction of telomerase in human osteoblasts.

Stromelysin-1 (MMP-3) in synovial fluid of patients with rheumatoid arthritis has potential to cleave membrane bound Fas ligand

OBJECTIVE

To investigate the relationship between matrix metalloproteinases (MMP) and the soluble form of Fas ligand (sFasL) in the synovial fluid (SF) of patients with rheumatoid arthritis (RA), and to determine which MMP have a major role in cleaving FasL.

METHODS

The concentrations of sFas and sFasL in SF from 48 patients with RA and 43 patients with osteoarthritis (OA) were measured using specific ELISA. The levels of different MMP (MMP-1, 2, 3, 7, 9) in SF were also measured by ELISA. The active forms of gelatinases were detected by gelatin zymogram. Human FasL-expressing transfected cells (hFasL/L5178Y) were used to investigate whether FasL is cleaved from membrane bound FasL.

RESULTS

Significantly higher levels of MMP-1, 3, and 9 were found in SF from RA patients compared to OA patients, but MMP-7 was not detectable in either group. The concentrations of sFas and sFasL in SF were also higher in RA than in OA patients. However, there was no relationship between the concentration of sFas and sFasL. Among MMP, MMP-3 concentrations in SF were closely correlated with the level of sFasL and with disease activity of RA. Enzymatic cleavage assay indicated that MMP-3 has potential to cleave the FasL expressed on hFasL/L5178Y cells and to produce sFasL.

CONCLUSION

There was significant correlation between the concentration of sFasL and MMP-3 in SF of patients with RA. In addition, our data indicate that the shedding of FasL may be regulated by MMP-3 in the joint of patients with RA.

Decreased cellular activity and replicative capacity of osteoblastic cells isolated from the periarticular bone of rheumatoid arthritis patients compared with osteoarthritis patients

OBJECTIVE

Periarticular osteopenia is frequently observed in rheumatoid arthritis (RA). Bone loss has been considered to be at least partly due to inadequate bone formation, which in turn, is largely dependent on the number of osteoblasts and the osteoblastic activity. Normal human somatic cells undergo a finite number of cell divisions and ultimately enter a nondividing state called replicative senescence. It has been proposed that the telomere, the terminal sequence of chromosomes, is the mitotic clock that triggers senescence. In the present study, we sought to clarify the relationship between periarticular osteopenia and osteoblast replicative senescence in RA.

METHODS

We examined age-related changes in cellular activity (alkaline phosphatase activity, osteocalcin and C-terminal type I procollagen secretion, and cAMP response to parathyroid hormone), replicative capacity, and senescent cell expression in osteoblasts from periarticular bone samples obtained from 15 patients with RA and 15 age-matched patients with osteoarthritis (OA). Cellular replicative capacity was analyzed by the mean telomere length and in vitro remaining replicative lifespan of the cells.

RESULTS

In both OA and RA groups, the cell proliferation rate, the levels of osteoblastic markers, mean telomere length, and replicative lifespan in osteoblastic cells gradually decreased with the increasing age of the donor. The percentage of senescent osteoblastic cells in the periarticular bone increased with age in both groups, and the rate of expression of senescent cells was higher in RA patients than in age-matched OA patients. The osteoblastic activities and replicative capacity of osteoblastic cells from RA patients were lower than those from OA patients at any donor age. The age-related decreases in the osteoblastic activity and replicative capacity of osteoblastic cells from periarticular bone were greater in RA patients than in OA patients.

CONCLUSION

Our results suggest that osteoblast replicative senescence in periarticular bones occurs more rapidly with aging in RA than in OA patients and contributes to periarticular osteopenia in RA.

Significance of serum type IV collagenolytic activities and gelatinase levels for detection of metastasis in murine RCT sarcoma

We investigated the usefulness of serum type IV collagenolytic activities and gelatinase levels as diagnostic markers of metastasis in the animal model of spontaneous lung metastasis by FITC-labeled type IV collagen degradation assay and zymographic analyses. High-metastatic RCT(+) and low-metastatic RCT(-) clones were used in the present study. The mean serum type IV collagenolytic activity in the RCT(+) group started to increase from two weeks after hind limb amputation, and was 0.45 and 1.29 unit/ml at three and four weeks. These values were significantly higher than those in the control group (p < 0.01 at three weeks; p < 0.001 at four weeks). A correlation between the number of lung nodules and serum type IV collagenolytic activities in the RCT(+) group was found (r = 0.89, p < 0.001). Zymographic analyses indicated that 105-kD gelatinolytic activities of the RCT(+) group were higher than those of the RCT(-) group at three and four weeks. Thus, type IV collagenolytic activities and serum gelatinase levels might be valuable markers for the detection of metastasis.

Reduced expression of the regulatory CD4+ T cell subset is related to Th1/Th2 balance and disease severity in rheumatoid arthritis

OBJECTIVE

To elucidate the involvement of the regulatory CD4+ T cells that produce high levels of interleukin-10 (IL-10) and low levels of IL-4 and IL-2 in the pathogenesis of rheumatoid arthritis (RA), we investigated whether the frequency of this type of CD4+ T cell subset in peripheral blood lymphocytes (PBL) or synovial lymphocyte infiltrates of patients with RA correlated with disease severity and histologic features in rheumatoid synovium.

METHODS

PBL and synovial lymphocyte infiltrates were isolated from peripheral blood samples and synovial tissues obtained from 25 patients with RA. Control specimens were obtained from 18 patients with osteoarthritis (OA) and 10 patients with traumatic injuries of the knee joint. CD4+ T cell subsets were categorized as Th1 (production of interferon-gamma [IFNgamma], but not IL-4), Th2 (production of IL-4, but not IFNgamma), or CD4+ T cell subsets producing IL-10, IL-2, or IL-4. The percentages of these T helper subsets among PBL and among synovial infiltrating lymphocytes were determined by an intracellular staining assay with flow cytometric analysis.

RESULTS

The level of expression of CD4+ T cells producing IL-10 but not IL-2 and IL-4 in the peripheral blood and synovial tissue was significantly lower in RA patients than in OA patients and trauma patients. In RA patients, the frequency of this type of CD4+ T cell subset among synovial infiltrating CD4+ T cells was inversely correlated with the frequency of Th1 cells and the Th1/Th2 balance in synovial lymphocytes, serum C-reactive protein value, disease activity score, and the degree of synovial lining hyperplasia and lymphocyte infiltration in rheumatoid synovium. There was a reciprocal relationship between the frequency of Thl cells and CD4+ T cells producing IL-10 but not IL-2 and IL-4 in the peripheral blood of RA patients.

CONCLUSION

In RA, reduced expression of the CD4+ T cell subset producing IL-10 but not IL-2 and IL-4 may be responsible for the dominance of Th1 over Th2 cells at sites of inflamed synovium and in the peripheral blood. Decreases in this type of CD4+ T cell subset may induce the down-regulation of T cell tolerance and exacerbate the inflammatory process in RA.

Cementless cup supporter for protrusio acetabuli in patients with rheumatoid arthritis

The MC cup supporter is an acetabular reinforcement ring for the Harris-Galante (HG) cementless porous-coated socket. This supporting ring has been used with autogenous bone graft since 1991 in the management of protrusio acetabuli in patients with rheumatoid arthritis (RA). We have reviewed 15 hips in 13 patients at an average of 53.6 months (range 24-84 months) after operation. The clinical results of total hip arthroplasty (THA) in protrusio acetabuli using this ring were satisfactory. All grafts appeared to have united radiologically with no radiolucent lines between graft and acetabulum.

Reduced expression of the regulatory CD4+ T cell subset is related to Th1/Th2 balance and disease severity in rheumatoid arthritis

OBJECTIVE

To elucidate the involvement of the regulatory CD4+ T cells that produce high levels of interleukin-10 (IL-10) and low levels of IL-4 and IL-2 in the pathogenesis of rheumatoid arthritis (RA), we investigated whether the frequency of this type of CD4+ T cell subset in peripheral blood lymphocytes (PBL) or synovial lymphocyte infiltrates of patients with RA correlated with disease severity and histologic features in rheumatoid synovium.

METHODS

PBL and synovial lymphocyte infiltrates were isolated from peripheral blood samples and synovial tissues obtained from 25 patients with RA. Control specimens were obtained from 18 patients with osteoarthritis (OA) and 10 patients with traumatic injuries of the knee joint. CD4+ T cell subsets were categorized as Th1 (production of interferon-gamma [IFNgamma], but not IL-4), Th2 (production of IL-4, but not IFNgamma), or CD4+ T cell subsets producing IL-10, IL-2, or IL-4. The percentages of these T helper subsets among PBL and among synovial infiltrating lymphocytes were determined by an intracellular staining assay with flow cytometric analysis.

RESULTS

The level of expression of CD4+ T cells producing IL-10 but not IL-2 and IL-4 in the peripheral blood and synovial tissue was significantly lower in RA patients than in OA patients and trauma patients. In RA patients, the frequency of this type of CD4+ T cell subset among synovial infiltrating CD4+ T cells was inversely correlated with the frequency of Th1 cells and the Th1/Th2 balance in synovial lymphocytes, serum C-reactive protein value, disease activity score, and the degree of synovial lining hyperplasia and lymphocyte infiltration in rheumatoid synovium. There was a reciprocal relationship between the frequency of Thl cells and CD4+ T cells producing IL-10 but not IL-2 and IL-4 in the peripheral blood of RA patients.

CONCLUSION

In RA, reduced expression of the CD4+ T cell subset producing IL-10 but not IL-2 and IL-4 may be responsible for the dominance of Th1 over Th2 cells at sites of inflamed synovium and in the peripheral blood. Decreases in this type of CD4+ T cell subset may induce the down-regulation of T cell tolerance and exacerbate the inflammatory process in RA.

Different mechanisms of synovial hyperplasia in rheumatoid arthritis and pigmented villonodular synovitis: the role of telomerase activity in synovial proliferation

OBJECTIVE

To elucidate the involvement of telomerase activity in the pathogenesis of rheumatoid arthritis (RA) and pigmented villonodular synovitis (PVS).

METHODS

Peripheral blood lymphocytes (PBL), synovial infiltrating lymphocytes, and synoviocytes were isolated from peripheral blood samples and synovial tissue obtained from 18 patients with RA, 9 with PVS, 12 with osteoarthritis (OA), and 10 with knee joint trauma. Cellular telomerase activity was measured by the telomeric repeat amplification protocol assay. In RA patients, the telomerase activity level in synovial infiltrating lymphocytes was assessed for correlations with histologic features in rheumatoid synovium.

RESULTS

A high level of telomerase activity was detected in the PBL and synovial infiltrating lymphocytes from RA patients and in the synoviocytes from PVS patients, whereas the enzyme activity was expressed at a low-to-borderline level in the PBL and synovial lymphocytes from OA, PVS, and trauma patients and was absent in the synoviocytes from RA as well as OA and trauma patients. In RA patients, the telomerase activity level in synovial infiltrating lymphocytes was significantly correlated with the intensity of synovial lining hyperplasia, microvessel proliferation, lymphocyte infiltration, and percentage of synovial cells positive for proliferating cell nuclear antigen in rheumatoid synovium.

CONCLUSION

Telomerase activation in lymphocytes may provide insights into the progression of synovitis and synovial proliferation in RA. Moreover, the enzyme may be implicated in the proliferation of synoviocytes in PVS.

Biochemical effect of intra-articular injections of high molecular weight hyaluronate in rheumatoid arthritis patients

OBJECTIVE

The purpose of this study was to analyze the biochemical characteristics of synovial fluids after treatment of patients with rheumatoid arthritis (RA) with intra-articularly injected hyaluronate (HA).

TREATMENT

In a double-blind study, 13 patients received intra-articular injections of 1% HA in phosphate buffered saline (PBS) while 13 other patients were injected 0.01% HA in PBS, as the control group. Injections were administered once a week for five weeks.

METHODS

Clinical efficacy and characteristics of synovial fluid were compared between groups.

RESULTS

Significant clinical improvement was observed in the HA-treated group compared to the control group. The viscosity of retained synovial fluid increased. Stringing and HA concentration increased significantly whereas the concentrations of protein and chondroitin sulfate 4 and 6 decreased significantly. The HA molecular weight remained the same in both groups.

CONCLUSION

Intra-articular HA injection altered the properties of synovial fluid and proved efficacious for patients with RA.

Effects of tumor cell-derived interleukin 1 alpha on invasiveness of metastatic clones of murine RCT sarcoma through endothelial cells

Interleukin 1 alpha (IL-1alpha) production and invasiveness through mouse lung endothelial cells (MLE) were investigated in high-metastatic RCT+ and low-metastatic RCT- clones established from poorly differentiated murine sarcoma. Apparently, a higher level of IL-1alpha was derived from RCT+ cells than from RCT- cells. In an invasion assay, the number of cells which penetrated the MLE monolayer in RCT+ was significantly greater than that in RCT-. The invasiveness of RCT+ and RCT- cells was stimulated by additional recombinant mouse IL-1alpha (rIL-1alpha) in a dose-dependent manner. Anti-mouse IL-1alpha monoclonal antibody (anti-IL-1alpha mAb) significantly inhibited the invasiveness of RCT+ and RCT- cells through the MLE monolayer. However, in RCT+ cells these effects were higher than in RCT- cells. In an attachment assay, the ability of RCT+ cells to attach to the MLE monolayer was significantly higher than that of RCT- cells. The attachment ability of RCT+ and RCT- cells to the MLE monolayer was significantly increased by the pretreatment with rIL-1alpha in a dose-dependent manner. In a retraction assay, conditioned medium of RCT+ stimulated the retraction of the MLE monolayer more markedly in comparison with conditioned medium of RCT-. The retraction of the MLE monolayer was stimulated by additional rIL-1alpha in a dose-dependent manner. The increased retraction of the MLE monolayer was closely associated with the enhancement in tumor cell invasiveness. These findings suggest that IL-1alpha derived from RCT+ and RCT- cells might contribute to the enhancement of tumor cell invasion by stimulating the attachment to the MLE monolayer and retraction of the MLE monolayer.

1alpha,25-dihydroxyvitamin D3 inhibits in vitro invasiveness through the extracellular matrix and in vivo pulmonary metastasis of B16 mouse melanoma

We investigated the role of 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) in modulating tumor cell invasiveness through the extracellular matrix (ECM) and pulmonary metastasis in B16 mouse melanoma. The pretreatment of B16 cells for 48 hours with 1alpha,25(OH)2D3 significantly inhibited in vitro invasiveness through the ECM by a mechanism that is not directly correlated with the inhibition of cell proliferation. When cells were treated with 1alpha,25(OH)2D3 for only 8 hours during the assay, no inhibitory effect was observed, suggesting that pretreatment with the hormone for more than 8 hours is necessary to inhibit the invasive potential of B16 cells. The activity of B16 cells to adhere to reconstituted basement membrane (Matrigel) and type IV collagenolysis was inhibited by pretreatment of the cells with 1alpha,25(OH)2D3 for 48 hours. Cell motility was not influenced by the hormone. Mice were inoculated subcutaneously with 3 x 106 B16 cells and were given 1alpha,25(OH)2D3 (0.5 microg/kg) or vehicle daily for 28 days, beginning 1 day after tumor inoculation. In the 1alpha,25(OH)2D3-treated group, no significant inhibition in exponential tumor growth, body weight, and serum level of calcium was observed until the twenty-eighth day. The mean serum concentration of the hormone was about 50 ng/mL, and there were no significant changes in its concentration during the treatment period. In both spontaneous and experimental metastasis models of tumor-bearing mice, treatment with 1alpha,25(OH)2D3 inhibited pulmonary metastasis. These findings suggest that 1alpha,25(OH)2D3 acts on B16 cells, inhibiting invasiveness through the ECM that is caused by the inhibition of cell adhesion to the ECM and the degradation of the ECM by the cells. 1alpha,25(OH)2D3 may have the potential to inhibit metastasis by a mechanism that is not exclusively based on its anti-cell proliferative effect.

Cystic spinal cord tumors: magnetic resonance imaging correlated to histopathological findings

We report the characteristics of magnetic resonance imaging (MRI) of cystic intradural extramedullary spinal cord tumors (cystic neurilemmoma, epidermoid cyst, and enterogenous cyst). T1-weighted MRI enhanced with gadolinium-DTPA clearly demonstrated the rim morphology of these tumors. The comparison between the rim enhancement pattern and histopathological findings offered possible qualitative diagnosis of these cystic spinal cord tumors by MRI.

Tirapazamine is metabolized to its DNA-damaging radical by intranuclear enzymes

Tirapazamine (TPZ), a new anticancer drug that is currently in Phase II and III clinical trials, has a unique mechanism of action. Its cytotoxicity is selective for hypoxic cells in solid tumors and results from DNA damage produced by a free radical, which is generated by enzymatic reduction of the parent molecule. However, there is no agreement as to which enzyme(s) are involved. Here, we have measured both DNA damage and TPZ metabolism in A549 human lung cancer cells and in isolated nuclei derived from the cells. We show that, although the nuclei metabolize TPZ at a rate that is only 20% of that of whole cells, they have levels of DNA damage that are similar to those of the cells. We also show that TPZ radicals that are formed outside nuclei do not contribute to intranuclear DNA damage. Thus, essentially all of the DNA damage from TPZ results from radicals generated within the nucleus, and the 80% of the drug metabolism that occurs in the cytoplasm is probably irrelevant for the activity of this drug in killing hypoxic cells.

Familial predisposition for lumbar degenerative disc disease. A case-control study

STUDY DESIGN

A case-control study using magnetic resonance imaging and plain radiography to evaluate whether a family history of lumbar disc herniation is a risk factor for disc degeneration.

OBJECTIVES

To evaluate the significance of a family history of operated lumbar disc herniation in the development of lumbar disc degeneration and lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

There are only a few epidemiologic studies indicating that a family history of intervertebral disc herniation is a risk factor for juvenile disc herniation. Recently, similarities in degenerative findings of the lumbar spine between identical twins have been reported.

METHODS

In the case group, 24 patients who were the immediate relatives of patients who had undergone surgery for disc herniation and who presented or had a history of low back pain and/or unilateral leg pain were included. Control individuals included 72 age- and gender-matched outpatients who reported low back pain and/or leg pain without a family history of operated disc herniation. The incidence, level, and topographic location of disc herniation/diffuse bulge; the incidence and grade of disc degeneration observed on magnetic resonance images; and degenerative changes suggesting disc degeneration observed on plain radiographs were compared between the relatives of patients with disc herniation (cases) and the controls.

RESULTS

The incidence of disc degeneration at L4-L5 and L5-S1 in cases (L4-L5, 18/24; L5-S1, 18/24) and controls (L4-L5, 45/72; L5-S1, 43/72) was similarly high. However, the grade of disc degeneration according to magnetic resonance imaging signal intensity on the T2-weighted sagittal image using Schneiderman's four-grade classification was significantly more severe in cases (L4-L5: Grade 1, 6/24; Grade 2, 4/24; Grade 3, 13/ 24; Grade 4, 1/24; L5-S1: Grade 1, 6/24; Grade 2: 3/24, Grade 3: 12/24, Grade 4: 3/24) than in controls (L4-L5: Grade 1, 27/72; Grade 2, 24/72; Grade 3, 20/72; Grade 4, 1/72; P = 0.034; L5-S1: Grade 1, 29/72; Grade 2, 23/72; Grade 3, 13/72; Grade 4, 7/72; P = 0.023; Mann-Whitney U test). The incidence of disc herniation/diffuse bulge at L4-L5 (16/24) and L5-S1 (11/24) in cases was higher than that in controls (L4-L5, 33/72; P = 0.07; L5-S1, 17/ 72; P = 0.04; chi-square test).

CONCLUSION

The current study provided evidence that a family history of operated lumbar disc herniation has a significant implication in lumbar degenerative disc disease. There may be a genetic factor in the development of lumbar disc herniation as an expression of disc degeneration.

Nitric oxide induced by tumor cells activates tumor cell adhesion to endothelial cells and permeability of the endothelium in vitro

Human fibrosarcoma HT1080 cell surface phenotype analysis revealed the expression of "cluster of differentiation 15" (CD15) antigen and to a lesser extent, of "very late antigen-4" (VLA-4). Expression of "endothelial-leukocyte adhesion molecule-1" (ELAM-1) was negligible on resting human umbilical vascular endothelial cells (HUVECs), but its expression could be induced by HT1080 conditioned medium. HT1080 cell adhesion to HUVECs was partially dependent on CD15/ELAM-1 adhesion molecules. HT1080 cell adhesion to HUVECs induced the enhancement of nitric oxide (NO) production from HUVECs. Exogenous NO and NO from HUVECs enhanced ELAM-1 expression on HUVECs, HT1080 cell adhesion to HUVECs, permeability of the HUVEC monolayer, and HT1080 cell invasion through the HUVEC monolayer. These enhancements were not induced by NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). These results suggest that NO expression induced by tumor cells via the CD15/ELAM-1 adhesion system may contribute to enhancement of tumor cell adhesion to endothelial cells and hyperpermeability of the endothelium, facilitating tumor cell invasion.

Evaluation of the prognosis of cancer patients with metastatic bone tumors based on serial bone scintigrams

We counted the lesions at the time of detection of bone metastases and calculated the rate of increase in the number of bone metastases from changes in serial bone scintigrams, and investigated the usefulness of serial scintigrams as a prognostic indicator in patients with metastatic bone tumors. Subjects were 112 patients with bone metastases from four types of primary lesion: 21 with prostate cancer, 27 breast cancer, 39 lung cancer and 25 stomach cancer. Of these, 18 (prostate), 19 (breast), nine (lung) and eight (stomach) underwent serial bone scintigrams in which bone metastases were first detected and identified as progressing. The numbers of lesions at the time of detection of bone metastases for prostate and stomach cancers were significantly greater than those for lung cancer. The rate of increase in the number of bone metastases for stomach cancer was significantly higher than that for prostate or breast cancers. There was no correlation between the survival time after the detection of bone metastases and the number of lesions at the time of detection in the four types of cancer. However, in prostate cancer, a negative correlation existed between the survival time after the detection of bone metastases and the rate of increase in the number of bone metastases. Thus, in patients with bone metastases from prostate cancer, it appears that the rate of increase in the number of bone metastases, estimated from serial bone scintigrams, was indicative of prognosis.

Effects of dibutyryl cyclic adenosine monophosphate on nucleolar organizer regions and epidermal growth factor receptor of Dunn osteosarcoma cells

We investigated the characteristics of nucleolar organizer regions (NORs) and epidermal growth factor receptor (EGFR) on differentiated Dunn osteosarcoma in response to dibutyryl cyclic adenosine 3',5'-monophosphate (Bt2cAMP). In the presence of 3 mM Bt2cAMP, the mean number of NORs was significantly decreased in 24 hrs and 48 hrs compared with the untreated group. Also, EGFR affinity was decreased and the EGFR number was increased in response to the cellular differentiation by Bt2cAMP. The decrease in EGFR affinity might be considered as an indicator of differentiation or the mature state of the cells. Thus, the present study provides a new clue to support differentiation of osteosarcoma cells from the viewpoint of NORs findings and EGFR analysis as a differentiation marker.

Effects of ethane-1-hydroxy-1, 1 diphosphonate on Dunn osteosarcoma cells

We investigated the effects of ethane-1-hydroxy-1, 1 diphosphonate (EHDP) on Dunn osteosarcoma cells in vivo and in vitro. In in vivo study, an increase of tumor volume was significantly suppressed in the EHDP administered groups compared with the control group. Histologically, Dunn osteosarcoma cells' viability was maintained after EHDP administration. However, fatty degeneration of tumor tissue was suspected in two of eight mice in the 5.0 mg/kg EHDP administered group. In vitro study, EHDP inhibited DNA synthesis and induced morphological changes, such as pycnotic cells. These findings show that the growth of Dunn osteosarcoma cells is inhibited by EHDP.

Stable translocations detected by fluorescence in situ hybridization: a rapid surrogate end point to evaluate the efficacy of a potentiator of tumor response to radiotherapy

Testing potential modifiers of the response of tumors to radiation therapy requires large, expensive, and time-consuming clinical trials. It would, therefore, be of value to have a rapid surrogate end point of tumor response that could be used to evaluate such modifiers. We here propose that radiation-induced stable chromosome translocations measured by fluorescence in situ hybridization (FISH) could fulfill this purpose. The assay requires that the ratio of nonlethal stable translocations to lethal dicentric aberrations be unity and not change with radiation dose and that radiation-induced stable translocations remain in the tumor cell population essentially indefinitely after irradiation. We have tested these assumptions with four human tumor cell lines in vitro at doses of 1-5 Gy and found them to be valid. We also modified the response to fractionated irradiation of a human tumor xenograft in three different ways and quantitated the tumor response using clonogenic cell survival and using the FISH stable translocation assay. Both assays gave similar values for the extent of radiation modification. These data suggest that this assay could allow clinical evaluation of potential radiation sensitizers with fewer patients and in shorter times than is the case with conventional clinical trials.

Effects of 1,25-dihydroxyvitamin D3 on tumor cell invasion to the extracellular matrix in human fibrosarcoma HT1080 cells and its correlation with laminin

We investigated the role of the active form of vitamin D, 1,25-dihydroxyvitamin D3[1,25(OH)2D3], in promoting tumor cell invasiveness through the extracellular matrix, and showed that 1,25(OH)2D3-induced reduction of laminin production by the cells was correlated with the inhibitory effect of the hormone on tumor cell invasiveness. 1,25(OH)2D3 significantly inhibited invasiveness through the matrix, type IV collagenolytic and migratory activity, but not cell attachment to the matrix in human fibrosarcoma HT1080 cells. The 1,25(OH)2D3-induced inhibition showed the same dose dependency and magnitude for invasiveness as for the effects on type IV collagenolysis and cell migration. 1,25(OH)2D3 inhibited laminin production from the cells in a dose-dependent manner. The inhibitory effects of 1,25(OH)2D3 on the invasiveness, type IV collagenolysis and cell migration appeared to parallel the hormone-induced reduction of laminin production. Antilaminin monoclonal antibody, blocking the activity of laminin in the culture medium, inhibited HT1080 cell invasiveness. In the presence of exogenous laminin, 1,25(OH)2D3-induced inhibition of invasion was not observed. These findings suggest that 1,25(OH)2D3 acts on HT1080 cells, inhibiting the expression of laminin from the cells, and that the reduced laminin expression leads to the inhibition in the type IV collagenolytic and migratory activity of the cells, and consequently, to the inhibition of invasiveness through the extracellular matrix.

Regulation of gelatinase production and invasiveness by organ-specific fibroblasts in high- and low-metastatic clones from murine RCT sarcoma

Regulation of gelatinase production, invasiveness and migration activity by organ-specific fibroblasts from embryo, subcutaneous and lung tissues of mice were investigated in high-metastatic RCT+ and low-metastatic RCT- clones established from a poorly differentiated murine sarcoma. In the conditioned media of RCT+ cells, mouse skin fibroblasts (MSF) obtained from the tissue of tumor origin (orthotopic) stimulated the production of the 105-kD gelatinase more than C3H/ 10T1/2 clone 8 (C3H/10 T1/2 CL8) or mouse lung fibroblasts (MLF). In the conditioned media of RCT- cells, however, cocultivation with fibroblasts showed only slight stimulatory effects on the production of the 105-kD gelatinase. In the invasion assay, using a reconstituted basement membrane (matrigel), RCT+ cells cocultivated with MSF showed significantly higher invasiveness than those cocultivated with C3H/10T1/2 CL8 or MLF. However, no significant differences were shown in the invasiveness of RCT- cells in cocultivation with three types of fibroblasts and in cultivation without fibroblasts. There was no significant difference in migration activity between RCT+ and RCT- cells cultivated alone. But in the cocultivation of both clones with MSF, the migration activity of RCT+ cells was significantly higher than that of RCT- cells. These findings suggest that MSF might delineate the difference in characteristics related to the metastatic potential of RCT+ and RCT- cells through regulation by organ-specific factors.

Prognostic value of the doubling time of serum C-reactive protein and alkaline phosphatase levels in primary bone and soft tissue tumors

We investigated the clinical relevance of doubling time (DT) of serum laboratory data obtained in routine clinical examination of patients with primary bone and soft tissue tumors, in comparison with major clinical and pathological parameters (age at presentation, sex, tumor size, location, clinical stage and histologic grade) by uni- and multivariate analyses. In 64 patients with primary bone and soft tissue tumors (primary bone tumors: 39, primary soft tissue tumors: 25) and 68 cancer patients, the pretreatment DT values of serum C-reactive protein (CRP), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), calcium (Ca), phosphate (P) levels were measured, as well as the erythrocyte sedimentation rate (ESR: mm/60 min); these values were then compared with overall survival, local recurrence-free survival and metastasis-free survival. Only DT of CRP and ALP (CRP-DT, ALP-DT) were found to be correlated with disease outcome in patients with primary bone and soft tissue tumors. In cancer patients, only CRP-DT showed a relation with clinical stage and histologic grade, but the ALP-DT in patients with bone metastasis was significantly shorter than that in patients with metastases at other sites or in those with no metastasis. Among all tumor patients, those with bone metastasis showed the shortest ALP-DT compared with those with lung, liver and brain metastasis. Univariate analysis showed that shorter CRP-DT and ALP-DT are associated with poor overall survival, and the development of local recurrence and metastasis. These findings suggest that pretreatment CRP- and ALP-DT could be additional prognostic parameters for disease outcome in patients with primary malignant bone and soft tissue tumors. However, in multivariate analysis, only ALP-DT, but not CRP-DT, was an independent prognostic parameter for these disease outcomes.

Significance of serum levels of type I procollagen peptide and intact osteocalcin and bone mineral density in patients with ossification of the posterior longitudinal ligaments

This study was performed to evaluate the correlation between serum biochemical marker levels of bone metabolism and bone mineral density (BMD) in patients with ossification of the posterior longitudinal ligaments (OPLL). In addition, the efficacy of these markers in the prediction of the progression of OPLL was also examined. In 40 patients with OPLL, and in age- and gender-matched controls (n = 36), the levels of C-terminal extension peptide of type I procollagen (PICP) and intact osteocalcin were quantitated by a sandwich enzyme-linked immunosorbent assay as serum markers of bone formation. BMD of the whole body was measured using dual-energy X-ray absorptiometry. Serum PICP and intact osteocalcin levels were significantly increased in patients with OPLL. There was a significant correlation between serum bone formation marker levels and BMD in both the OPLL and the control groups. Patients with radiological progression of OPLL showed a level higher than the mean + 2 SD of controls in PICP, intact osteocalcin, and BMD. In addition, the levels of serum PICP and intact osteocalcin increased in correspondence with the progression of OPLL without statistical significance. In patients without any growth of OPLL, however, all the parameters were below the mean + 2 SD of controls. Thus, aggravation of bone formation activity was suggested to be closely correlated with the development of OPLL. In addition, serial measurements of these parameters might be useful for estimating the progression of OPLL.