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Histopathologische Untersuchungen belegen, dass COVID-19 nicht nur das respiratorische System und das Gerinnungssystem, sondern auch zahlreiche andere Organe betrifft. Da die Patienten bei schweren Verläufen häufig zusätzlich an Erkrankungen wie beispielsweise Diabetes mellitus oder chronischer Niereninsuffizienz leiden, müssen bei der Bewertung der Ergebnisse Veränderungen, die auf eine SARS-CoV-2-Infektion zurückzuführen sind, von denjenigen, die durch die Grunderkrankung verursacht wurden, abgegrenzt werden. [ABSTRACT FROM AUTHOR]

Immer mehr zur Behandlung solider Tumoren zugelassene Wirkstoff e verlangen zwingend einen molekularpathologischen Biomarkertest, um die Wirksamkeit der gezielten Erstlinientherapie zu sichern oder bei Entwicklungvon Resistenzmutationen einen Therapiewechsel zu initiieren. [ABSTRACT FROM AUTHOR]

Ein umfassendes genomisches Tumorscreening kann bei Patient:innen mit einem fortgeschrittenen bzw. metastasierten Mammakarzinom gegebenenfalls neue Therapieoptionen eröffnen und Informationen über Resistenzmechanismen des Tumors hinsichtlich bestimmter Therapien liefern. Eine personalisierte Therapie könnte auch bei Brustkrebs die Gesamtansprechrate verbessern sowie das progressionsfreie Überleben und das Gesamtüberleben verlängern. [ABSTRACT FROM AUTHOR]

Simple Summary: Rrisk assessment of microsatellite instability (MSI) and copy-number (CN)-low endometrial adenocarcinomas constitutes a major challenge. We aimed to identify tissue-based morphologic biomarkers that might help in the prognostic stratification, comprehensively analyzing one finding cohort (TCGA-UCEC) and two independent validation cohorts. Histomorphologic parameters (WHO grading, tumor budding (TB), tumor–stroma ratio, tumor-infiltrating lymphocytes (TIL), "microcystic, elongated, fragmented" (MELF) pattern) were analyzed. For each quantitative parameter, a two-tiered system was developed utilizing systematically determined cutoffs. In MSI tumors, TB (≥3 buds/high-power field) was detected to be an independent prognostic factor for inferior outcomes and lymph node metastases. The finding was confirmed in two validation cohorts. For CN-low tumors, solely WHO grading was independently prognostic with inferior outcomes for high-grade tumors. Therefore, we propose the utilization of TB and WHO-based grading, two tissue-based and easy-to-assess biomarkers, in MSI/CN-low endometrial carcinomas for improved clinical management. The molecular characterization of endometrial endometrioid adenocarcinomas has provided major advances in its prognostic stratification. However, risk assessment of microsatellite instability (MSI) and copy-number (CN)-low cases remains a challenge. Thus, we aimed to identify tissue-based morphologic biomarkers that might help in the prognostic stratification of these cases. Histomorphologic parameters (WHO grading, tumor budding (TB), tumor–stroma ratio (as a quantitative description of stromal desmoplasia), tumor-infiltrating lymphocytes (TIL), "microcystic, elongated, fragmented" (MELF) pattern) were analyzed in resection specimens of the TCGA-UCEC cohort (n = 228). For each quantitative parameter, a two-tiered system was developed utilizing systematically determined cutoffs. Associations with survival outcomes were calculated in univariate and multivariate analysis and validated in two independent cohorts. In MSI tumors, only TB remained an independent prognostic factor. TB (≥3 buds/high-power field) was associated with inferior outcomes and with lymph node metastases. The prognostic significance of TB was confirmed in two validation cohorts. For CN-low tumors, established grading defined by the WHO was independently prognostic with inferior outcomes for high-grade tumors. The evaluation of TB might help in identifying MSI-patients with unfavorable prognosis who, e.g., could benefit from lymphadenectomy. WHO-based grading facilitates independent prognostic stratification of CN-low endometrioid adenocarcinomas. Therefore, we propose the utilization of TB and WHO-based grading, two tissue-based and easy-to-assess biomarkers, in MSI/CN-low endometrial carcinomas for improved clinical management. [ABSTRACT FROM AUTHOR]

Background: The prognostic significance of tumour budding (TB) and minimal cell nest size (MCNS) was shown in human papillomavirus (HPV)-negative head and neck squamous cell carcinomas (HNSCC). However, the optimisation of cutpoints, the prognostic impact in HPV-positive HNSCC, and the comparison with other histopathological grading systems are insufficiently investigated. Methods: TB and MCNS were analysed digitally in 1 and 10 high-power fields (HPF) of 331 HPV-positive and HPV-negative cases from TCGA. Optimising the cutpoints a new cellular dissociation grading (CDG) system was defined and compared to the WHO grading and the Brandwein–Gensler (BG) risk model. Results: The two-tiered CDG system based solely on TB yielded optimal prognostic stratification with shortened overall survival for CDG-high cases. Optimal cut-offs were two buds (1 HPF) and six buds (10 HPF), respectively. Analysing MCNS did not add prognostic significance to quantifying TB. CDG was a significant prognostic marker in HPV-negative and HPV-positive tumours and prognostically superior to the WHO and BG systems. High CDG was associated with clinically occult lymph-node metastases. Conclusions: The most comprehensive study of TB in HNSCC so far confirmed its prognostic impact in HPV-negative tumours and for the first time in HPV-positive tumours. Further studies are warranted to evaluate its applicability for therapy guidance in HNSCC. [ABSTRACT FROM AUTHOR]

• Analysis of recurrent/metastatic head and neck cancer. • Feasibility of a 231-gene NanoString panel in determining the molecular subtypes. • Tumor budding prognostically significant in recurrent/metastatic state. We aimed to evaluate the applicability of a customized NanoString panel for molecular subtyping of recurrent or metastatic head and neck squamous cell carcinoma (R/M−HNSCC). Additionally, histological analyses were conducted, correlated with the molecular subtypes and tested for their prognostic value. We conducted molecular subtyping of R/M−HNSCC according to the molecular subtypes defined by Keck et al. For molecular analyses a 231 gene customized NanoString panel (the most accurately subtype defining genes, based on previous analyses) was applied to tumor samples from R/M−HNSCC patients that were treated in the CeFCiD trial (AIO/IAG-KHT trial 1108). A total of 130 samples from 95 patients were available for sequencing, of which 80 samples from 67 patients passed quality controls and were included in histological analyses. H&E stained slides were evaluated regarding distinct morphological patterns (e.g. tumor budding, nuclear size, stroma content). Determination of molecular subtypes led to classification of tumor samples as basal (n = 46, 45 %), inflamed/mesenchymal (n = 31, 30 %) and classical (n = 26, 25 %). Expression levels of Amphiregulin (AREG) were significantly higher for the basal and classical subtypes compared to the mesenchymal subtype. While molecular subtypes did not have an impact on survival, high levels of tumor budding were associated with poor outcomes. No correlation was found between molecular subtypes and histological characteristics. Utilizing the 231-gene NanoString panel we were able to determine the molecular subtype of R/M−HNSCC samples by the use of FFPE material. The value to stratify for different treatment options remains to be explored in the future. The prognostic value of tumor budding was underscored in this clinically well annotated cohort. [ABSTRACT FROM AUTHOR]

As primary osseous metastasis is the main adverse prognostic factor in patients with Ewing tumours, a NOD/ scid mouse model for human Ewing tumour metastases has been established to examine the mechanisms of metastasis. The aim of this study was to evaluate the feasibility of diagnostic molecular imaging by small animal PET in this mouse model. Human Ewing tumour cells were transplanted into immune-deficient NOD/ scid mice via s.c injection ( n=17) or i.v. injection ( n=17). The animals (mean weight 23.2 g) were studied 2–7 weeks after transplantation using a submillimetre resolution animal PET scanner. To assess glucose utilisation and bone metabolism, mice were scanned after intravenous injection of 9.6 MBq (mean) 2-[18F]fluoro-2-deoxy- D-glucose (FDG) or 9.4 MBq (mean) [18F]fluoride. Whole-body PET images were analysed visually and semi-quantitatively [%ID/g, tumour to non-tumour ratio (T/NT)]. Foci of pathological uptake were identified with respect to the physiological organ uptake in corresponding regions. Subcutaneously transplanted Ewing tumours demonstrated a moderately increased glucose uptake (median %ID/g 2.5; median T/NT 2.2). After i.v. transplantation, the pattern of metastasis was similar to that in patients with metastases in lung, bone and soft tissue. These metastases showed an increased FDG uptake (median %ID/g 3.6; median T/NT 2.7). Osseous metastases were additionally visible on [18F]fluoride PET by virtue of decreased [18F]fluoride uptake (osteolysis; median %ID/g 8.4; median T/NT 0.59). Metastases were confirmed immunohistologically. Diagnostic molecular imaging of Ewing tumours and their small metastases in an in vivo NOD/ scid mouse model is feasible using a submillimetre resolution PET scanner. [ABSTRACT FROM AUTHOR]

: BackgroundBone marrow–derived stem cells are involved in tissue formation in transplanted organs. In human renal cell transplants, recipient-specific cells have been shown to participate in regeneration of interstitial tissue. In hepatic transplants, hepatocytes with a recipient sex chromosome pattern have been observed. Recruitment of stem cells in repair and regeneration of cardiac myocytes has been demonstrated in experimental ischemia. Recently, cardiac antral myocytes of recipient origin have been shown to populate transplanted hearts in gender-mismatched transplants.: MethodsUsing the flourescence in situ hybridization (FISH) technique we examined serial post-transplant right ventricular biopsies and sections of ventricle (at time of autopsy) of 4 gender-mismatched female-to-male transplanted hearts (graft survival 0.5 to 10 years, mean 5.1 years) for Y chromosomes within cardiac myocytes.: ResultsWe detected recipient-specific sex chromosomal patterns in single rare cardiac myocytes in 1 case in a serial biopsy after 7 years of transplant survival. The other serial biopsies, as well as the final sections at autopsy, showed no recipient pattern chromosomes within the myocytes. In addition, 2 cases demonstrated Y chromosomes in the smooth muscle of intracardiac arteries.: ConclusionDevelopment of recipient marrow–derived stem cells into functional myocytes in the ventricle of transplanted hearts is a rare feature. The higher percentage of stem cell population in the cardiac atria may be a feature of tissue repair and/or an early feature of transplant physiology. Similar to other transplant organs, recipient stem cells are involved in tissue neovascularization. [Copyright &y& Elsevier]

Although necrosis and necroinflammation are central features of many liver diseases, the role of programmed necrosis in the context of inflammation-dependent hepatocellular death remains to be fully determined. Here, we have demonstrated that the pseudokinase mixed lineage kinase domain-like protein (MLKL), which plays a key role in the execution of receptor-interacting protein (RIP) kinase-dependent necroptosis, is upregulated and activated in human autoimmune hepatitis and in a murine model of inflammation-dependent hepatitis. Using genetic and pharmacologic approaches, we determined that hepatocellular necrosis in experimental hepatitis is driven by an MLKL-dependent pathway that occurs independently of RIPK3. Moreover, we have provided evidence that the cytotoxic activity of the proinflammatory cytokine IFN-γ in hepatic inflammation is strongly connected to induction of MLKL expression via activation of the transcription factor STAT1. In summary, our results reveal a pathway for MLKL-dependent programmed necrosis that is executed in the absence of RIPK3 and potentially drives the pathogenesis of severe liver diseases. [ABSTRACT FROM AUTHOR]

Superficial soft tissue sarcomas (sSTS) are an important and frequent subtype of soft tissue sarcoma (STS). A wider knowledge of this tumor type may lead to better strategies in tumor therapy. An institutional review was performed on all patients with primary sSTS of the extremities and trunk operated on between 1990 and 2003. The medical records of 108 patients with sSTS were analyzed. The local recurrence rate was 11% after a median of 25 (mean 42) months. Metastases occurred in 21 patients (19%), and 79 patients lived without evidence of disease after a mean follow-up of 112 ± 42 months. Mean survival time was 89 months at a cumulative 5-year survival rate of 85%. R0 resection significantly enhanced cumulative survival ( p = .001), as did patient age < 60 years ( p = .002), tumor grading G1 and G2 compared to G3 ( p = .004), absence of positive lymph nodes ( p = .018), and no occurrence of metastases ( p = .001). Tumor size ≤ 5 cm reduced the local recurrence rate significantly ( p = .044). Significant multivariate risk factors for metastases were age ≥ 60 years ( p = .016) and tumor grade G3 ( p = .021). Patients with sSTS who are ≥60 years of age or who have G3 tumors have a high risk of distant metastases. Patients with T2 tumors have an elevated risk for local recurrence. Certainly all patients with sSTS should be in a tight after-care program to allow early diagnosis of local recurrence or distant metastases. Age < 60 years, tumor grade G1/2, no positive regional lymph nodes (N0), and a R0 resection are significant prognostic factors for survival. [ABSTRACT FROM AUTHOR]

Pulmonary alveolar proteinosis (PAP) due to deficiency of the common β-chain (βc) of the interleukin–3 (IL–3)/IL–5/granulocyte–macrophage colony–stimulating factor (GM–CSF) receptors is a rare monogeneic disease characterized by functional insufficiency of pulmonary macrophages. Hematopoietic stem cell gene therapy for restoring expression of βc-protein in the hematopoietic system may offer a curative approach. Toward this end, we generated a retroviral construct expressing the murine βc (mβc) gene and conducted investigations in a murine model of βc-deficient PAP. Functional correction of mβc activity in mβc–/– bone marrow (BM) cells was demonstrated by restoration of in vitro colony formation in response to GM-CSF. In addition, in a murine in vivo model of mβc-deficient PAP mβc gene transfer to hematopoietic stem cells not only restored the GM-CSF-sensitivity of hematopoietic progenitor cells but also, within a period of 12 weeks, almost completely reversed the morphologic features of surfactant accumulation. These results were obtained despite modest transduction levels (10–20%) and, in comparison to wild-type mice, clearly reduced βc expression levels were detected in hematopoietic cells. Therefore, our data demonstrating genetic and functional correction of mβc–/– deficiency in vitro as well as in a murine in vivo model of PAP strongly suggest gene therapy as a potential new treatment modality in βc-deficient PAP.Molecular Therapy (2008); 16 4 757–764 doi:10.1038/mt.2008.7 [ABSTRACT FROM AUTHOR]

Abstract: In Ewing’s sarcoma family of tumours (ESFT), the clinically most adverse prognostic parameters are the presence of tumour metastasis at time of diagnosis and poor response to neoadjuvant chemotherapy. To identify genes differentially regulated between metastatic and localised tumours, we analysed 27 ESFT specimens using Affymetrix microarrays. Functional annotation of differentially regulated genes revealed 29 over-represented pathways including PDGF, TP53, NOTCH, and WNT1-signalling. Regression of primary tumours (n =20) induced by polychemotherapy was found to be correlated with the expression of genes involved in angiogenesis, apoptosis, ubiquitin proteasome pathway, and PI3 kinase and p53 pathways. These findings could be confirmed by in vitro cytotoxicity assays. A set of 46 marker genes correctly classifies these 20 tumours as responding versus non-responding. We conclude that expression signatures of initial tumour biopsies can help to identify ESFT patients at high risk to develop tumour metastasis or to suffer from a therapy refractory cancer. [Copyright &y& Elsevier]

Purpose: To analyze the relationship between chromosomal instabilities and clinicopathological factors in synovial sarcoma (SS). Methods: Twenty-two fresh-frozen SS were analyzed by metaphase comparative genomic hybridization (CGH). Additional microarray CGH was performed in 13 cases. Results: Fourteen patients with SYT–SSX1 rearrangements and nine patients with biphasic tumor subtypes had better prognosis than the eight patients with SYT–SSX2 rearrangements and 13 patients with monophasic subtypes, respectively. Gains (average 3.0) were more frequent than losses (average 1.0). Frequent gains were identified on chromosomal regions 2, 6q, 7, 8q, 12, 17q, 18q, and 21q, whereas frequent losses were over-lapped on chromosomes 1p31–p35, 3p, 6q, 16, and 17p. High-level gains were observed on chromosomes 1q21–q31, 7, 8, 12, 17q, 18q, and 21q. Thirteen monophasic and nine biphasic tumors had an average of 5.1 and 2.8 aberrations, respectively. Patients with tumors harboring numerous aberrations (≥3) had a worse clinical course. Microarray CGH more specifically detected genetic imbalances including gains in MDM2, MSH2, KCNK12, DCC, CDK2, ERBB3, SAS, and CDK4 and losses in HRAS, RASSF1, and CCND1. Gain of SAS was an important prognostic factor of SS. Conclusion: We have identified several factors influencing the prognosis of SS patients by metaphase and microarray CGH. [ABSTRACT FROM AUTHOR]

Clear cell sarcoma of soft tissue (CCSST) represents a highly malignant tumor of the musculoskeletal system that is characterized by the chromosomal translocation t(12;22)(q13;q12) of the Ewing sarcoma gene (EWSR1) and activating transcription factor 1 (ATF1). In a former microarray expression study, we identified ERBB3, a member of the epidermal growth factor receptor (EGFR) family, as a promising new diagnostic marker in the differential diagnosis of CCSST. Here we show that, besides ErbB3, all CCSST cell lines (n = 8) also express the ErbB2 receptor or the ErbB4 receptor, representing an adequate coreceptor of ErbB3. The phosphorylation status of ErbB3 revealed these receptor pairs to be either constitutively activated in CCSST cells with high neuregulin-1 (NRG1) expression (n = 4) or activatable by exogenic NRG1 in cells showing low amounts of NRG1 mRNA (n = 4). Exogenous NRG1 stimulated the growth of a subset of CCSST cells but did not affect the kinetics of another subset. This difference was not strictly dependent on endogenous NRG1 expression; however, the growth-inhibiting effect of the pan-ErbB tyrosine kinase inhibitor CI-1033 or PD158780 clearly correlated with NRG1 expression indicating an autocrine growth stimulation loop, which may constitute an interesting target of new therapeutic strategies in this tumor entity. [ABSTRACT FROM AUTHOR]

Laser holographic interferometry is based on the superimposition of the holograms of different motional states of an object on a single holographic storing medium. Using a combination of holographic interferometry and endoscopic imaging, we tried to detect areas of focally disturbed tissue elasticity in gastric cancer preparations. By connecting a mobile electronic speckle pattern interferometry (ESPI) camera system (light source: double frequency Nd:YAG laser, lambda = 532 nm) to different types of endoscopes, ex vivo experiments were performed on ten formalin fixed human stomachs, nine containing adenocarcinomas and one with a gastric lymphoma. Linking the endoscopic ESPI camera complex to a fast image processing system, the method of double pulse exposure image subtraction was applied at a video frame rate of 12.5 Hz. Speckle correlation patterns and corresponding phase difference distributions resulting from gastric wall deformation by gentle touch with a guide wire were analyzed. Tumor-free gastric areas showed high-contrast concentric fringes around the point of stimulation. In contrast, fringe patterns and filtered phase difference distributions corresponding to the areas of malignancy in all the cases were characterized by largely parallel lines, indicating that stimulation of rigid tumor tissue primarily led to tilting. Our ex vivo investigations of malignant gastric tumors show that the application of dynamic holographic endoscopy makes it possible to distinguish areas of malignancy from surrounding healthy tissue based on the differences in tissue elasticity. [ABSTRACT FROM AUTHOR]

In all, 85%of Ewing's sarcoma family tumors (ESFT), a neoplasm of unknown histogenesis, express EWS-FLI1 transcription factor gene fusions. To characterize direct target genes avoiding artificial model systems, we cloned genomic DNA from ESFT chromatin precipitating with EWS-FLI1. We now present a comprehensive list of 99 putative transcription factor targets identified, for the first time, by a hypothesis-free approach based on physical interaction. Gene-derived chromatin fragments co-precipitating with EWS-FLI1 were nonrandomly distributed over the human genome and localized predominantly to the upstream region and the first two introns of the genes. At least 20%of putative direct EWS-FLI1 targets were neural genes. One-third of genes recovered showed a significant ESFT-specific expression pattern and were found to be altered upon RNAi-mediated knockdown of EWS-FLI1. Among them, MK-STYX, encoding a MAP kinase phosphatase-like protein, was consistently expressed in ESFT. EWS-FLI1 was found to drive MK-STYX expression by binding to a single ETS binding motif within the first gene intron. MK-STYX serves as precedence for successful recovery of direct EWS-FLI1 targets from the authentic ESFT cellular context, the most relevant system to study oncogenic mechanisms for the discovery of new therapeutic targets in this disease.Oncogene (2005) 24, 2512-2524. doi:10.1038/sj.onc.1208455 Published online 14 February 2005 [ABSTRACT FROM AUTHOR]

Cytokine resistance is a well-established feature of melanoma cell progression and represents also a major obstacle in immunotherapy of patients with metastatic melanoma. To check whether suppressors of cytokine signalling (SOCS) play a role in cytokine resistance and tumor progression of melanoma, we investigated the expression and regulation of SOCS-1, an established negative regulator of interleukin-6 (IL-6) and interferon (IFN) signalling.In vitroSOCS-1 transcripts were detectable by RT-PCR in 8 out of 8 human melanoma cell lines derived from different tumor stages. Normal human melanocytes also expressed SOCS-1 mRNA in the presence or absence of artificial growth factors. Both IL-6 andα-IFN induced rapid and transient SOCS-1 mRNA expression in WM35 and WM9 melanoma cells. At the protein level, SOCS-1 was undetectable in normal human melanocytes whereas uniformly expressed in all tested melanoma cell lines. The aberrant SOCS-1 protein expression in melanoma cells was recapitalizedin situas shown by immunohistochemical analysis. SOCS-1 immunoreactivity was closely related to tumor invasion (Clark level), tumor thickness according to Breslow, and stage of the disease. In contrast, melanocytes in normal skin or melanocytic nevi lacked SOCS-1 protein expression. Our findings show that melanoma cells express a member of the SOCS family, SOCS-1,in vitroandin situ. SOCS-1 is a progression marker of human melanoma and may downregulate biological responses by endogenous and/or therapeutically administered cytokines. [ABSTRACT FROM AUTHOR]

OBJECTIVES: A variety of imaging techniques are available to diagnose bile duct strictures; the most effective imaging technique, however, has not been established yet. In the present study, we compared the impact of endoscopic retrograde cholangiopancreatography (ERCP), intraductal ultrasonography (IDUS), and magnetic resonance cholangiopancreatography (MRCP) with regard to diagnosing bile duct strictures.METHODS: We prospectively examined 33 patients with jaundice due to bile duct strictures by ERCP plus IDUS and MRCP. The objectives were to assess diagnostic quality of imaging, complete presentation of the bile duct, and differentiation of malignant from benign lesions. Surgical and histopathological correlations, which were used as the gold standard, were available in all cases since all included patients underwent laparotomy.RESULTS: Diagnostic image quality for ERCP was 88% and 76% for MRCP (p>0.05). Comparing ERCP and MRCP, complete presentation of the biliary tract was achieved in 94% and 82%, respectively (p>0.05). ERCP and MRCP allowed correct differentiation of malignant from benign lesions in 76% and 58% (p= 0.057), respectively. By supplementing ERCP with IDUS, the accuracy of correct differentiation of malignant from benign lesions increased significantly to 88% (p= 0.0047).CONCLUSIONS: Comparing ERCP with MRCP, we found adequate presentation of bile duct strictures in high imaging quality for both techniques. ERCP supplemented by IDUS gives more reliable and precise information about differentiation of malignant and benign lesions than MRCP alone without additional imaging sequences.(Am J Gastroenterol 2004;99:1684-1689) [ABSTRACT FROM AUTHOR]

Purpose. The objective of this study was to evaluate breast carcinomas for the expression of cyclooxygenase-2 (Cox-2) using a tissue microarray (TMA) and to determine its clinical and prognostic relevance. Methods. We analyzed Cox-2 expression in 600 samples from 200 breast carcinomas immunohistochemically performing TMA technology and semiquantitative analysis. Results were correlated with various clinicopathological variables and follow-up data. Expression of estrogen receptor, progesterone receptor, Ki-67, and Her-2/neu-oncogene was analyzed and correlated with Cox-2 status. Results. We observed a moderate or strong cytoplasmic staining for Cox-2 in 78 (40.6%) of breast carcinomas. Increased Cox-2 expression corresponded to higher pT stage (P=0.038), amplification of Her-2/neu (P=0.032), lymphovascular invasion (P=0.006), a high MIB-1 labeling index (LI) (P<0.001), and histological grading (P=0.013). We also observed an inverse relationship between strong Cox-2 expression and estrogen and progesterone receptor content of tumors (P=0.037 and P=0.010). However, we could not demonstrate a significant association between Cox-2 staining and overall survival or disease free survival time. Conclusions. These results suggest that Cox-2 expression is significantly associated with less differentiated and more aggressive breast carcinomas and might therefore be a useful prognostic indicator as well as a target for therapy. [ABSTRACT FROM AUTHOR]

We characterized the chromosomal alterations in eight osteosarcoma cell lines (OST, HOS, U-2 OS, ZK-58, MG-63, SJSA-1, Saos-2, and MNNG) by comparative genomic hybridization (CGH); gains and losses of DNA sequences were defined as chromosomal regions with a fluorescence ratio, wherein all of the 95% confidence interval was above 1.25 and below 0.75, respectively. In four of 8 cell lines, multicolor karyotyping (MK) was added. CGH revealed the average number of aberrations per cell line was 20.8 (range: 10–31); the average numbers of gains and losses were 11.1 and 9.6, respectively. The frequent gains were identified on 1p21∼q24, 1q25∼q31, 7p21, 7q31, 8q23∼q24, and 14q21; frequent losses were at 18q21∼q22, 18q12, 19p, and 3p12∼p14. High-level gains were observed on 8q23∼q24, 5p, and 1p21∼p22. MK revealed the most common translocations in the four cell lines were t(8;9), t(1;3), t(3;5), t(1;13), t(2;6), t(3;17), t(1;15), t(10;20), and t(6;20). Chromosomes 1, 3, 8, 9, and 20 were most frequently involved in translocation events. The concordance rate of aberrations in CGH and translocations in MK was 76%. MK was useful to identify the chromosomal alterations and as a supplement to the CGH results in three of four chromosomes. [Copyright &y& Elsevier]

We report that human secretory breast carcinoma (SBC), a rare subtype of infiltrating ductal carcinoma, expresses the ETV6-NTRK3 gene fusion previously cloned in pediatric mesenchymal cancers. This gene fusion encodes a chimeric tyrosine kinase with potent transforming activity in fibroblasts. ETV6-NTRK3 expression was confirmed in 12 (92%) of 13 SBC cases, but not in other ductal carcinomas. Retroviral transfer of ETV6-NTRK3 (EN) into murine mammary epithelial cells resulted in transformed cells that readily formed tumors in nude mice. Phenotypically, tumors produced glands and expressed epithelial antigens, confirming that EN transformation is compatible with epithelial differentiation. This represents a recurrent chromosomal rearrangement and expression of a dominantly acting oncogene as a primary event in human breast carcinoma. [Copyright &y& Elsevier]

Presents a study that compared allelic imbalances in human and murine osteosarcomas to identify genetic changes critical for osteosarcomagenesis. Background on osteosarcoma; Comparison between the human and mouse syntenic regions; Information on the association of disturbances of developmental control genes with tumorigenesis.

Objective. To compare a custom-made femoral stem with a conventional cementless stem for initial stability in human femurs.Design. The bone-femoral prosthesis interface motion was measured in vitro using displacement transducers. Combined axial and torsional loads simulating single-leg stance, loading were applied.Background. The custom-made prosthesis is a cementless femoral stem fabricated from the patient''s CT- reconstruction. To justify its clinical use its design has to be tested regarding his primary stability.Methods. Seven pairs of human cadaveric femurs were used for testing the custom-made prosthesis versus a conventional cementless stem. Subsidence, rotation and interface motion were measured with load cycles up to 2000 N.Results. The critical interface motion of 150 μm for the cementless prosthesis was not exceed for both types of prosthesis. The custom-made prosthesis enlarged in its metaphyseal part showed a decrease of dynamic micromotions and rotation behavior in the proximal region compared to the Alloclassic prosthesis stem.Conclusions. The initial stability of the custom-made femoral stem was comparable to that of a conventional femoral stem.RelevanceThe data set for initial stability justifies the clinical use of a custom-made femoral stem in primary hip replacement. An individualized stem fit into the endosteal cortical bone decrease micromotion. [Copyright &y& Elsevier]

Telomere maintenance is regarded as a key mechanism in overcoming cellular senescence in tumor cells and in most cases is achieved by the activation of telomerase. However there is at least one alternative mechanism of telomere lengthening (ALT) which is characterized by heterogeneous and elongated telomeres in the absence of telomerase activity (TA). We evaluated the prevalence of TA, gene expression of telomerase subunits and ALT in relation to telomere morphology and function in matrix producing bone tumors and in osteosarcoma cell lines and present evidence of a direct association of ALT with telomere dysfunction and chromosomal instability. Telomere fluorescence in situ hybridization (T-FISH) in ALT cells revealed elongated and shortened telomeres, partly in unusual configurations and loci, dicentric marker chromosomes and signal-free chromosome ends. Free ends give rise to end-to-end associations and may induce breakage-fusion-bridge cycles resulting in an increased number of complex chromosomal rearrangements, as detected by multiplex-FISH (M-FISH). We propose that ALT cannot be seen as an equivalent to telomerase activity in telomere maintenance. Its association with telomere dysfunction and chromosomal instability may have major implications for tumor progression. Oncogene (2001) 20, 3835–3844. [ABSTRACT FROM AUTHOR]