Decorin and biglycan are characterized by a distinct expression pattern in the normal rat kidney, whereas the presence of their endocytosis receptor protein correlates with the expression of both proteoglycans. Decorin is almost completely absent in the normal mesangium. Both proteoglycans become up-regulated in various models of renal disease. The mesangial accumulation of decorin in the anti-Thy-1 glomerulonephritis that is observed in spite of the only slightly enhanced mRNA expression could result from decreased decorin turnover and/or increased mesangial retention.

Oestrogen receptor expression is generally a sign of better tumour differentiation and comparatively good clinical outcome in invasive breast cancer. However, oestrogen receptor-positive, poorly differentiated carcinomas with a poor clinical outcome exist. The underlying genetic mechanisms and the genes involved remain obscure, even though chromosome 7p gains seem to be associated with these uncommon tumours. In this study, we compared two subsets of oestrogen receptor-positive breast cancers, which differed in tumour grade, cytogenetic instability, and tumour proliferation, for their differential gene expression in order to identify proteins involved in the progression of oestrogen receptor-positive breast cancers. We were able to show by means of subtractive suppression hybridization, real-time reverse transcriptase PCR, and tissue microarray analysis that expression of the bone morphogenetic protein receptor IB (BMPR-IB) is a major hallmark of the progression and dedifferentiation of breast cancer. Strong expression of BMPR-IB was associated with high tumour grade, high tumour proliferation, cytogenetic instability, and a poor prognosis in oestrogen receptor-positive carcinomas. Western blot analysis revealed that downstream signalling of this receptor is mainly mediated via phosphorylation of SMAD 1 in oestrogen receptor-positive breast cancer. Even though BMPR-IB was expressed in oestrogen receptor-positive and -negative breast cancers, an impact on tumour grade, proliferation, and cytogenetic instability, as parameters of tumour progression, could only be demonstrated in oestrogen receptor-positive carcinomas. This pro-proliferative effect was complemented by significant anti-apoptotic activity, indicated by XIAP and IAP-2 expression in BMPR-IB-positive carcinomas. These results show that the BMP/SMAD pathway is activated in breast cancer and may contribute to breast cancer progression and dedifferentiation in oestrogen receptor-positive breast cancer. The definition of this pathway characterizes a new potential target in the molecular treatment of invasive breast cancer.

Monocyte activation, apoptosis and differentiation are hallmarks of most inflammatory vascular disorders. We studied the effects of heme oxygenase-1 (HO-1) induced by its substrate hemin on apoptosis, caspase-3 expression and the differentiation of freshly isolated human monocytes. Hemin induced HO-1 in a dose- and time-dependent fashion as measured by semi-quantitative RT-PCR and flow cytometry. Apoptosis was markedly suppressed by hemin in cells rendered apoptotic by serum deprivation or dexamethasone as determined by flow cytometric detection of annexin V binding or transmission electron microscopy (TEM). The specific HO-1 inhibitor zinc protoporphyrin (ZnPP) reversed the effects of hemin on monocyte apoptosis and diminished cell lifespan. Surprisingly, the cytoprotective effects of hemin were positively correlated with caspase-3 up-regulation. Hemin-induced apoptosis suppression was enhanced by the caspase-3 inhibitor DEVD-CHO, indicating that caspase-3 was active in a pro-apoptotic fashion. Hemin inhibited CD95 as a putative cytoprotective mechanism. Morphological studies and detection of CD86 showed that monocytes differentiated into macrophages in response to hemin after relatively long incubation times, a phenomenon that might be provoked by caspase-3-regulated pathways. Our results confirm a similar cytoprotective effect of hemin/HO-1 for monocytes as has been shown for other cells, despite caspase-3 up-regulation. The fact that HO-1 may adversely affect monocyte survival and differentiation could be of particular significance in future therapies for occlusive vascular diseases or transplant rejection.

The overexpression of beta-catenin and p53 is associated with a decreased event-free survival in deep aggressive fibromatosis. Further studies are required to establish whether these findings can lead to an improvement in the treatment of this rare neoplasm.

The natural course of pheochromocytomas (PCC) cannot be predicted for certain on the basis of primary histology, their malignant character can only be confirmed by the occurrence of metastases during follow-up. Based on the recently proposed PASS score for evaluation we examined 37 adrenal (36 sporadic and one familial) and six sporadic extra-adrenal paragangliomas (all designated as pheochromocytomas) with a 'malignant histology' to find additional predictive factors. Drawing upon the follow-up (18 months to 12 years, mean 5.8 years) metastasized (n ¼ 20) and nonmetastasized (n ¼ 23) courses could be distinguished. Metastasized PCC revealed significantly (P ¼ 0.03) more copy number changes on comparative genomic hybridization (CGH) (mean 8.3) than nonmetastasized tumors (mean: 4.3). The most frequent chromosomal alterations were losses on 1p (75.6%) and 3q (44%). Both were detected with identical frequency in metastasized and nonmetastasized PCC. A gain on 17q (P ¼ 0.025) was significantly predominant in malignant courses and suggests similarities in the genetic origin and progression of PCC and neuroblastomas. The proliferative activity (MIB-1 score) of metastasized PCC (n ¼ 20) was found to be significantly higher in metastasized tumors (mean 12.8% vs mean 3.5%). In contrast, the semiquantitatively scored membrane-bound staining of CD 44-S was stronger in tumors without metastases (mean 2.1 vs mean: 0.25) during the follow-up period (Po0.01). Although the results correspond to the established weight differences the tumor weight does not appear to be an independent prognostic factor. Our study suggests that CD 44-S and MIB-1 immunostaining as well as the CGH results might complement the PASS score in predicting a metastasized course of PCC. Regardless of tumor weight, tumors with a 'malignant histology' are highly prone to metastasize when more than 5% of MIB1-positive nuclei are present or CD44-S immunostaining is negative, or both. PCC with 10 or more copy number changes on CGH must be referred to as malignant tumors. The safe distinction between benign and malignant pheochromocytomas (PCC) is an unresolved dilemma beleaguering diagnostic pathology to the present day. In most cases the decision is therefore based on the occurrence of metastases as the only proof of malignancy. Recently, Thompson 1 proposed an adrenal gland scoring scale (PASS) capable of determining malignancy solely on the grounds of conventional histological criteria. Within the framework of this scoring scale, less prognostic importance is attributed to vascular and capsular invasion (with a score of 1 point each) than to growth pattern, necroses and characteristics of proliferative behavior (high cellularity, cellular monotony, more than three mitoses/10 HPF and the occurrence of atypical mitoses). These characteristics each have a score of two points).In recent reports on adrenal and extra-adrenal PCC a number of chromosomal aberrations were discussed with a view to their possible involvement

Monocytes interact and cross-talk with platelets in many settings including inflammation, hemostasis, or vascular disorders. During inflammatory diseases, there is a rapid targeting of monocytes and platelets to points of inflammation and endothelial injury, where they lie side-by-side. In this in vitro study, we investigated different interactions between monocytes and platelets and elucidated whether platelets might affect monocyte apoptosis. Freshly isolated human monocytes were rendered apoptotic by serum deprivation or CD95 ligation and cocultured with platelets. Monocyte apoptosis was determined by flow cytometry, TUNEL staining, DNA electrophoresis, and transmission electron microscopy imaging. We could show that monocyte apoptosis was highly suppressed when platelets were added to the cultures. Transmission electron microscopy depicted that monocytes completely ingested thrombocytes by phagocytosis. Blocking thrombocyte uptake by the phagocytosis inhibitor cytochalasin D abrogated the enhanced monocyte survival and led to high apoptosis levels. Monocyte survival was paralleled by down-regulation of caspase-9 and -3 and up-regulation of heat shock protein 70 during uptake of platelets. Platelet supernatants and contents of platelet granules were ineffective in altering monocyte senescence. Also, ingestion of latex beads or zymosan by monocytes was ineffective to mimic platelet-dependent rescue from apoptosis. In conclusion, this study shows that platelets can suppress apoptosis of monocytes by a specific phagocytosis-dependent process with further consequences for atherosclerotic or inflammatory conditions.

Long-term prognosis in kidney transplant recipients depends on multiple factors. To investigate whether mild proteinuria within the first 6 months following transplantation is a determinant of the long-term function and survival of kidney transplants, 357 patients transplanted between 1980 and 1990 were retrospectively examined over a period of 5 years. 25.5% of the patients developed an early proteinuria between 0.25 and 1.0 g/day over 6 or more months. This group was well matched concerning gender, age of recipient, underlying disease, time on hemodialysis, donor age, cold ischemia time and HLA mismatches with the group without proteinuria (n = 266). Five-year transplant survival in the group with proteinuria was 58.9% in contrast to 85.6% in recipients without proteinuria. Intermittent proteinuria did not worsen long-term prognosis. Proteinuria of 12 months or longer further reduced 5-year transplant survival to 42.6%. Over the whole observation period, serum creatinine in recipients with proteinuria was about 0.5 mg/dl higher as compared with patients without proteinuria. No correlation between proteinuria and gender, age of recipient, duration of hemodialysis, age of donor, cold ischemia time and mismatches could be detected. In conclusion, early proteinuria apparently is not due to established donor or recipient factors. However, there is a strong correlation of proteinuria with worse transplant function and survival.

BackgroundBecause of the lack of suitable in vivo models of giant cell tumor of bone (GCT), little is known about its underlying fundamental pro-tumoral events, such as tumor growth, invasion, angiogenesis and metastasis. There is no existing cell line that contains all the cell and tissue tumor components of GCT and thus in vitro testing of anti-tumor agents on GCT is not possible. In this study we have characterized a new method of growing a GCT tumor on a chick chorio-allantoic membrane (CAM) for this purpose.MethodsFresh tumor tissue was obtained from 10 patients and homogenized. The suspension was grafted onto the CAM at day 10 of development. The growth process was monitored by daily observation and photo documentation using in vivo biomicroscopy. After 6 days, samples were fixed and further analyzed using standard histology (hematoxylin and eosin stains), Ki67 staining and fluorescence in situ hybridization (FISH).ResultsThe suspension of all 10 patients formed solid tumors when grafted on the CAM. In vivo microscopy and standard histology revealed a rich vascularization of the tumors. The tumors were composed of the typical components of GCT, including (CD51+/CD68+) multinucleated giant cells whichwere generally less numerous and contained fewer nuclei than in the original tumors. Ki67 staining revealed a very low proliferation rate. The FISH demonstrated that the tumors were composed of human cells interspersed with chick-derived capillaries.ConclusionsA reliable protocol for grafting of human GCT onto the chick chorio-allantoic membrane is established. This is the first in vivo model for giant cell tumors of bone which opens new perspectives to study this disease and to test new therapeutical agents.