Biomedical subjects

Reinhard von Wasielewski

Publications and source records attributed to Reinhard von Wasielewski.

At least 19 recordsLinked to original sources

PubMed2006

Legumain expression as a prognostic factor in breast cancer patients.

Invasive tumor cells and their microenvironments are enriched with a broad spectrum of different proteases. Legumain, a novel asparaginyl endopeptidase, has been observed to be highly expressed in several types of solid tumors. However, there is no data available identifying the relationship of legumain expression and clinicopathologic or biological variables in invasive breast cancer. For the first time, the prevalence of legumain expression in invasive breast cancer (n = 432) and non-neoplastic breast tissues (n = 128) was investigated by immunohistochemistry. Three staining patterns were observed in the cytoplasm: diffuse positivity, tiny dots and vesicles. Whereas vesicular positivity in the majority of tumor cells was significantly correlated to an adverse outcome, cytoplasmic and dot-like staining showed no prognostic effect. Vesicular positivity was observed in 24% of carcinomas, but only in one case of non-neoplastic breast tissue (<1%; proliferative mastopathy). This staining pattern was found to be independent of other factors analysed as grading, nodal status or HER2 expression. Besides being of prognostic value, legumain might prove to be an important predictive factor in breast cancer, since its unique cleavage specificity is already used in prodrug activation strategies.

Breast Neoplasms↗

PubMed2006

p16INK4a expression and clinicopathologic parameters in renal cell carcinoma.

OBJECTIVES: The tumour suppressor gene p16INK4a is a cyclin-dependent kinase inhibitor, for which inactivation attributable to promoter hypermethylation or homozygous deletion has been described in malignancies. Little is known about p16INK4a protein levels in renal cell carcinoma (RCC) and its association with clinicopathologic parameters or disease progression. METHODS: The expression of the p16INK4a gene was analysed with the use of immunohistochemistry and tissue microarrays (TMA). Tissue cores were obtained from the primary tumour itself, the tumoural invasion front, and histologically benign peritumoural tissue of 397 nephrectomies. For statistical analysis, sections were classified into four groups according to the relative amount of positively stained cells: negative (0%), low (1-10%), intermediate (11-50%), and high positivity (>50%). Follow-up data were analyzed for 198 patients (follow-up period: 2-240 mo; median: 138 mo). RESULTS: Absent or low expression of p16INK4a was observed in 82% of tumour samples. No statistically significant association was found between protein levels detected in tumour, invasion front, or normal renal tissues and any of the clinicopathologic variables. Survival analysis by Kaplan-Meier revealed a significant association between high expression (>50%) of p16INK4a in tumours and better disease-specific survival (p=0.03, log-rank test). Cox regression analysis showed that p16INK4a expression is an independent covariate in disease-specific survival (p<0.01). CONCLUSIONS: The absence of p16INK4a expression in most tumour cells indicates that p16INK4a could be involved in the tumourigenesis of RCC. Immunohistochemically detected positivity for p16INK4a is a positive prognosticator for specific survival in both uni- and multivariate analyses.

Carcinoma, Renal Cell↗

PubMed2006

Hypothermic circulatory arrest with moderate, deep or profound hypothermic selective antegrade cerebral perfusion: which temperature provides best brain protection?

OBJECTIVE: Selective antegrade cerebral perfusion (SACP) seems to be associated with a better outcome compared to hypothermic circulatory arrest (HCA) alone. This study was undertaken to evaluate the influence of different SACP temperatures on the neurological integrity. METHODS: Twenty-six pigs were included in the study and assigned to 100 min HCA at 20 degrees C body temperature without (n = 6) or with either 10 degrees C (n = 6), 20 degrees C (n = 7) or 30 degrees C (n = 7) of SACP. Haemodynamics, metabolics and neurophysiology (EEG, SSEP, ICP, sagittal sinus saturation) were monitored. Animals were sacrified 4h after reperfusion and brains perfused for histological and molecular genetic assessment. RESULTS: There were no clinically relevant differences in haemodynamics between groups. The rise in ICP during SACP was significantly more marked in the 30 degrees C group (p < 0.05) and remained high during the entire experiment. In the 10 degrees C group the rise in ICP was postponed, but increased during reperfusion. The 20 degrees C group showed a slight increase of ICP over time, but remained significantly lower compared to HCA (p < 0.05). Sagittal sinus saturation decreased during SACP at 30 degrees C (p < 0.05). EEG recovery was most complete in the 20 degrees C group (p < 0.05). RT-PCR analysis of brain tissue revealed a reduction for heat shock protein (HSP-72) in 20 degrees C (p < 0.05) and 10 degrees C animals (p = 0.095). Histopathological evaluation showed a reduction of edema and eosinophilic cells in the groups treated with SACP. CONCLUSION: In this model, SACP is superior to HCA alone. Regarding the optimal temperature for SACP, it seems that 20 degrees C provides adequate brain protection in comparison to the potential detrimental effects of moderate (30 degrees C) and profound (10 degrees C) temperatures.

Animals↗

PubMed2006

Prognostic impact of Skp2 and p27 in human breast cancer.

PURPOSE: The cell cycle is controlled by cyclin-dependent kinases and one of the key players is the cyclin-dependent kinase inhibitor p27. The F-box protein Skp2 is a regulator of G1-S transition and promotes specifically the ubiquitin-mediated proteolysis of p27 via the proteasome pathway. In breast carcinomas, overexpression of Skp2 has been implicated in cell transformation and oncogenesis, but no data are available on the association of Skp2 and p27. The purpose was to evaluate the prevalence of Skp2 and p27 expression and determine whether a combined index has prognostic power in breast carcinomas. EXPERIMENTAL DESIGN: Three hundred and thirty-eight breast cancer specimens were analyzed for Skp2 and p27 expression by immunohistochemistry. Results were compared with classical histopathological criteria as well as other prognostic markers (ER, PR, HER2, p53, Ki-67) and correlated with the clinical outcome. RESULTS: Thirty-four percent of breast cancers analyzed showed both a high expression for Skp2 and a low expression for p27. In univariate Kaplan-Meier analysis, this combination was found to be significantly associated with a worse clinical course (p<0.0001). Including staging, grading and the other tested marker, the Skp2/p27 index proved to be of prognostic relevance in multivariate analysis. CONCLUSIONS: The combined assessment of Skp2 and p27 identifies aggressive breast cancer. In long-term follow-up, high Skp2 and low p27 indicate an unfavorable course. Beyond the prognostic importance of the Skp2/p27 index, it could serve as a predictive marker for new molecular targeted therapies aiming at Skp2.

Biomarkers, Tumor↗

PubMed2006

Genetically induced pancreatic adenocarcinoma is highly immunogenic and causes spontaneous tumor-specific immune responses.

Treatment options for pancreatic cancer are limited and often ineffective. Immunotherapeutic approaches are one possible option that needs to be evaluated in appropriate animal models. The aim of the present study was to analyze tumor-specific immune responses in a mouse model of pancreatic cancer, which mimics the human disease closely. C57BL/6 EL-TGF-alpha x Trp53-/- mice, which develop spontaneous ductal pancreatic carcinoma, were generated. EL-TGF-alpha x Trp53-/- mice developed spontaneous pancreatic tumors with pathomorphologic features close to the human disease. Tumor-specific CD8+ T-cell responses and IgG responses were analyzed in EL-TGF-alpha x Trp53-/- mice during tumor development and compared with mice with s.c. growing pancreatic tumors. In contrast to spontaneous pancreatic tumors, cell lines generated from these tumors were rejected after s.c. injection into wild-type mice but not in nude or RAG knockout mice. Direct comparison of spontaneous and s.c. injected tumors revealed an impaired infiltration of CD8+ T cells in spontaneous pancreatic tumors, which was also evident after adoptive transfer of tumor-specific T cells. Intratumoral cytokine secretion of tumor necrosis factor-alpha, IFN-gamma, IL-6, and MCP-1 was lower in spontaneous tumors as well as the number of adoptively transferred tumor-specific T cells. Our data provide clear evidence for tumor-specific immune responses in a genetic mouse model for pancreatic carcinoma. Comparative analysis of s.c. injected tumors and spontaneous tumors showed significant differences in tumor-specific immune responses, which will help in improving current immune-based cancer therapies against adenocarcinoma of the pancreas.

Animals↗

PubMed2006

Gene expression profile of the infective murine model for biliary atresia.

One hypothesis of the pathogenesis of biliary atresia (BA) is a virus-induced and immune-mediated injury to bile duct cells as mimicked in the rotavirus-induced murine model. This theory is supported by studies showing a predominant T helper cell response type 1-like phenotype of inflammation with increased interferon gamma-induced chemokines in the liver of humans and mice suffering from BA. Recent gene expression profiling studies using microarray analysis showed the induction of a proinflammatory state in human liver specimens with high analogies in extrahepatic biliary tissue of BA mice. The aim of the present study was a microarray analysis of gene expression in the liver of Balb/c mice, comparing infected mice that show the phenotype of BA versus infected mice without symptoms, thus trying to elucidate genes that are not related to the viral origin of this model, but to the specific pathogenesis of the clinical picture of BA. Fifteen mug of RNA, each of three BA-positive and three BA-negative mice, were pooled and comparatively hybridized to spotted cDNA microarrays containing 250 key genes with high relevance to immunological settings. We identified the 40 genes most differentially expressed in mice with and without BA. The majority of genes with higher expression in BA-positive mice encoded proinflammatory cytokines involved in the Th1 pathway, such as CCL2, CCL5, CCR5, CXCL10, CCL2, IL1F5 and in apoptosis, such as DDR3 and granzyme A and B. In this initial study of the molecular characterization of our RRV-induced BA mouse model system, we also found potential novel candidates important to BA etiology, such as growth hormone receptor and insulin-like growth factor. Of particular interest, very low expression of TIMD2 was observed in BA-positive mice. TIMD2 plays a critical role in the regulation of a Th2-type response through the inhibition of IFN gamma.

Animals↗

PubMed2005

Wnt/beta-catenin signaling mediates antineoplastic effects of imatinib mesylate (gleevec) in anaplastic thyroid cancer.

CONTEXT: Dysregulation of Wnt signaling is a key step in neoplastic thyrocyte proliferation. However, it is unclear whether the selective tyrosine kinase (TK) inhibitor, imatinib mesylate, is linked to the Wnt/beta-catenin cascade and is able to modulate the pathway. OBJECTIVE: Conflicting data are reported on the therapeutic effects of imatinib in anaplastic thyroid carcinomas (ATCs), but the molecular mechanism of action is unclear. Here, we further delineated the antitumor effects and the potential efficacy of imatinib in dedifferentiated thyroid carcinomas. RESULTS: Tissue microarray of histologically proven ATCs (n = 12) demonstrated that six of 12 tumors expressed at least one of the imatinib-sensitive TKs. Similarily, imatinib-sensitive TKs were detected in seven of 10 thyroid cancer cell lines derived from metastatic papillary, follicular, and ATCs. Coimmunoprecipitation in ARO cells demonstrated a direct link between c-abl and beta-catenin. Imatinib (10 microM for 48 h) drastically reduced beta-catenin expression and redistributed it from the nucleus to the cell membrane. It stabilized adherens junctions by increasing beta-catenin/E-cadherin binding and reduced the invasive potential of thyroid cancer. Furthermore, imatinib (10 microM for 48 h) attenuated T cell factor/lymphoid enhancer factor activity, reduced cyclin D1 levels and dose-dependently suppressed thyrocyte proliferation by half without affecting apoptosis. CONCLUSION: Our data provide a molecular mechanism for the antitumor activity of imatinib that may help to develop it as a therapeutic option in a subset of ATC patients.

Antineoplastic Agents↗

PubMed2005

Identification of differentially expressed genes in papillary thyroid carcinomas with and without rearrangements of the tyrosine kinase receptors RET and/or NTRK1.

BACKGROUND: The transforming capacities of RET and/or NTRK1 chimeric oncogenes as well as the molecular background of non-rearranged papillary thyroid carcinomas (PTCs) remain to be elucidated. To assess altered gene expression, we examined PTCs with and without tyrosine kinase receptor rearrangements by mRNA differential display (DD). MATERIALS AND METHODS: Six of 13 PTCs examined harbored RET chimeras (3x RET/PTC1, 1x RET/PTC3) and/or NTRK1 chimeras (2x trk, 1x TRK-T3, 2 unknown TRK hybrids). The method of DD analysis was refined by a novel fragment-recovery technique using a high-performance fluorescence scanner. RESULTS: Of 500 up- or down-regulated mRNA transcripts, 19 selected fragments were recovered, cloned, sequenced, and identified. The accuracy and high degree of reproducibility of the method was demonstrated. Differential expression of gene products with potential association to cell proliferation or tumor progression was observed, such as 14-3-3beta and Rab27a. Moreover, several gene products with unknown functions were demonstrated in PTCs bearing RET or NTRK1 hybrids versus rearrangement-negative PTCs, including a homologue of the Ig kappa light chain constant region. CONCLUSIONS: Candidate transcripts with presumed tumorigenic potential in other solid tumors may prove to be relevant in the progression of PTCs, too. Most promising is the isolation of several differentially expressed, yet unknown, genes that may open new insights in the pathogenesis or progression of PTC.

Adolescent↗

PubMed2005

Aberrant expression of transforming growth factor beta-1 (TGF beta-1) per se does not discriminate fibrotic from non-fibrotic chronic myeloproliferative disorders.

Transforming growth factor beta-1 (TGF beta-1) is a potent inducer of fibrosis and has been shown to be essential for the development of bone marrow fibrosis in an animal model of idiopathic myelofibrosis (IMF). IMF belongs to the Philadelphia chromosome negative chronic myeloproliferative disorders (Ph(-) CMPD). Megakaryocytes and platelets have been suggested as the major cellular source of TGF beta-1 in IMF. The osteoclastogenesis inhibitory factor osteoprotegerin (OPG) seems to be regulated by TGF beta-1 and substantial involvement of OPG expression in the process of osteosclerosis in IMF has recently been suggested. In order to determine TGF beta-1 expression in IMF and other Ph(-) CMPD, total bone marrow cells as well as laser-microdissected megakaryocytes were quantitatively analysed by real-time RT-PCR. OPG mRNA expression in fibrotic IMF was correlated with TGF beta-1 mRNA expression in a case-specific manner. Both OPG and TGF beta-1 were detected immunohistochemically in order to delineate cellular origin. When total bone marrow cells were investigated, TGF beta-1 mRNA expression was increased in some but not all cases of IMF (n = 21), with highest values in fibrotic cases. Unexpectedly, increased values were also observed in essential thrombocythaemia (ET, n = 11) when compared to non-neoplastic haematopoiesis (n = 38). Megakaryocytes isolated by laser microdissection displayed elevated TGF beta-1 mRNA levels in most of the CMPD samples with no significant differences discernible between fibrotic IMF, polycythaemia vera (PV) and ET. TGF beta-1 protein was predominantly expressed by the myeloid lineage in Ph(-) CMPD and non-neoplastic haematopoiesis, which, however, displayed lower expression. IMF cases with advanced fibrosis concomitantly overexpressed TGF beta-1 and OPG. Immunohistochemically, OPG expression was found in different stromal cells and a subfraction of megakaryocytes. In conclusion, enhanced TGF beta-1 expression occurs in megakaryocytes as well as myeloid cells in Ph(-) CMPD. TGF beta-1 may be necessary, but is not sufficient, to induce bone marrow fibrosis in IMF because non-fibrotic Ph(-) CMPD entities share this feature with IMF and cannot be discriminated from each other on the basis of TGF beta-1 expression.

Adult↗

PubMed2005

Searching for non-RET molecular alterations in medullary thyroid carcinoma: expression analysis by mRNA differential display.

Some 25%-70% of sporadic medullary thyroid carcinomas (MTCs) are associated with somatic mutations within the RET proto-oncogene. In a significant number of MTCs, however, no such genetic variations can be detected, which implies alternative pathogenic molecular alterations. To assess altered RET mutation-specific gene expression, and to identify yet unknown gene transcripts involved in the tumorigenesis of MTC, we performed an expression analysis by mRNA differential display (RT-DD). Snap-frozen tumor tissues and corresponding normal thyroid tissues of 8 patients suffering from MTC (6 sporadic, 2 hereditary tumors) were included in the study; 5/8 MTCs harbored RET point mutations (codons 618, 634, 918). The RT-DD method was refined by use of fluorescence-labeled arbitrary oligonucleotides, electrophoresis on an automated sequencer, and a novel fragment-recovery technique utilizing a high-performance fluorescence scanner. More than 400 differentially expressed mRNA transcripts--representing upregulated or downregulated genes in the compared tissues--were detected. In all, 28 selected fragments were recovered, cloned, sequenced, and identified. Differential expression of gene transcripts with known association to cell proliferation or tumor progression--such as annexin A2, Rab11a, trefoil proteins, superoxide dismutase (SOD1), mitochondrial displacement loop (D-loop), and G protein subunit gamma11--as well as of the neuroendocrine marker chromogranin was observed. Furthermore, several mRNA transcripts of yet unknown genes displayed mutation-specific upregulation or downregulation in MTC. Illumination of the molecular basis especially of C-cell carcinomas without detectable alterations of the RET receptor tyrosine kinase will be required for the development of therapeutic strategies for advanced tumors that cannot be bridled or cured by surgical interventions alone.

Adult↗

PubMed2005

Aberrant expression of platelet-derived growth factor (PDGF) and PDGF receptor-alpha is associated with advanced bone marrow fibrosis in idiopathic myelofibrosis.

The expression of members of the platelet-derived growth factor (PDGF) system in bone marrow cells derived from Idiopathic myelofibrosis (IMF) has been investigated by real-time RT-PCR. Increased expression of PDGFs and the corresponding PDGF receptor a could be demonstrated to be a feature of advanced fibrosis in IMF that is not demonstrable in the prefibrotic phase of the disease.

Disease Progression↗

PubMed2004

Biological significance of p27 and Skp2 expression in renal cell carcinoma. A systematic analysis of primary and metastatic tumour tissues using a tissue microarray technique.

p27 (p27/kip1) is involved in cell-cycle control, and loss of p27 expression may result in tumour development and/or progression. Association with Skp2 targets p27 for degradation. Using a tissue microarray technique, 171 primary renal cell carcinomas (RCCs) and 58 RCC metastases were immunostained for p27 and Skp2. p27 Immunoreactivity was noted in 83 of 129 (64%) clear cell, 6 of 22 (27%) chromophobe and 15 of 20 (75%) papillary tumours as well as 44 of 58 (76%) metastases. In clear cell cancers, high p27 expression (> or =50% of tumour cells) decreased with rising tumour stage (50% pT1/pT2 versus 20% pT3; P<0.001) and grade (44% G1/G2 versus 21% G3/G4; P=0.008). None of 22 chromophobe cancers showed high expression in contrast to 46 of 129 (36%) clear cell tumours (P<0.001). Skp2 expression was noted in 8 of 129 (6%) clear cell cancers and 11 of 55 (20%) metastases (P=0.008). Immunoreactivity increased with rising tumour stage (1% pT1/pT2 versus 11% pT3; P=0.03) and grade (1% G1/G2 versus 15% G3/G4; P=0.004) and was associated with sarcomatoid morphology (P<0.001). In multivariate analysis, patients with low p27 expression and Skp2 immunoreactivity in clear cell cancers had a less favourable outcome. In conclusion, p27 and Skp2 proved to be additional biomarkers in renal cancer pathology with both prognostic and diagnostic impact.

Adult↗

PubMed2004

Low-dose therapy with the long-acting erythropoietin analogue darbepoetin alpha persistently activates endothelial Akt and attenuates progressive organ failure.

BACKGROUND: The hematopoietic cytokine erythropoietin has cytoprotective effects in endothelial cells in vitro that are mediated through direct activation of the pro-survival Akt tyrosine kinase signaling pathway. We tested the hypothesis that low-dose therapy with the long-acting recombinant human erythropoietin analogue darbepoetin alpha protects vascular endothelium in vivo in a classic remnant kidney rat model characterized by severe endothelial damage, progressive vascular sclerosis, and ischemia-induced tissue fibrosis. METHODS AND RESULTS: Using a parallel group study design, we randomly assigned animals after 5/6 nephrectomy to treatment with either saline (n=36) or 0.1 microg/kg body wt darbepoetin (n=24) subcutaneously once weekly. We monitored hematocrit, blood pressure, and serum creatinine regularly and obtained renal tissue 6 weeks after nephrectomy for morphological and immunohistochemical analysis. Darbepoetin-treated animals had significantly improved survival compared with saline-treated controls (63% versus 33%; P<0.05), although hematocrit levels were similar in both groups. Darbepoetin treatment ameliorated endothelial damage; attenuated the composite tissue injury score (saline 1.9+/-0.4; darbepoetin 0.4+/-0.2; P<0.001), which included vascular sclerosis, glomerulosclerosis, and tubulointerstitial damage; and preserved renal function. We found persistent activation of the pro-survival Akt signaling pathway in endothelial and epithelial glomerular cells in darbepoetin-treated animals, accompanied by a significant reduction of apoptotic cell death in renal tissue. CONCLUSIONS: Low-dose darbepoetin treatment confers vascular and tissue protection that is associated with persistent stimulation of the pro-survival Akt signaling pathway. The use of recombinant human erythropoietin or analogues may have utility in preventing ischemia-related progressive vascular injury and organ failure.

Animals↗

PubMed2004

Prognostic value of cytotoxic T-lymphocytes and CD40 in biopsies with early renal allograft rejection.

After renal transplantation, different immunological and non-immunological factors lead to long-term allograft deterioration. Acute rejection episodes are one risk factor for chronic renal allograft dysfunction (CRAD). Following the current Banff classification the histological grade in acute rejection episodes is of limited prognostic value, therefore, additional morphological surrogate markers would be helpful. We investigated the biopsies of 91 patients with early acute rejection episodes for the immunohistochemical expression of key molecules (perforin, granzyme B, TIA-1, CD40) in the T cell-mediated rejection process. Staining results were correlated to long-term allograft outcome. Patients with greater than 2% of granzyme B or greater than 25% of CD40-positive cells in the interstitial infiltrate showed significantly shorter allograft survival. Patients with a CD40-positive vascular rejection or greater than 2% of granzyme B-positive cells in the interstitial infiltrate were significantly correlated with an earlier onset of CRAD. Our findings provide potential morphological surrogate markers in biopsies with early acute rejection episodes after renal transplantation. These could become part of combined clinical and histological algorithms, allowing patient-specific risk estimation and customized therapy options to be made.

Acute Disease↗

PubMed2004

Aberrant expression of insulin-like growth factor-2 (IGF-2) in Philadelphia chromosome negative chronic myeloproliferative disorders.

Philadelphia chromosome negative chronic myeloproliferative disorders (Ph- CMPD) comprise haematopoietic stem cell disorders with currently unknown underlying molecular defect. Insulin-like growth factor 2 (IGF-2) is an imprinted gene that is known to be involved in the regulation of normal cell growth and that is overexpressed by a variety of tumors. The expression of IGF-2 in bone marrow cells is largely unknown. In order to elucidate gene expression level, protein expression pattern, and a potential role of IGF-2 in the pathogenesis of Ph- CMPD, we quantitatively analyzed the expression of the IGF-2 gene in bone marrow cells of 69 cases with Ph- CMPD and 31 control cases by applying real-time RT-PCR. IGF-2 gene expression in idiopathic myelofibrosis (IMF) was significantly increased by up to 11-fold as compared to the control group (P < 0.0001). IMF also expressed higher IGF-2 gene level as compared to essential thrombocythaemia (ET) and polycythaemia vera (PV) (P < 0.0001, P = 0.005, respectively). Paranuclear IGF-2 protein could be demonstrated in IMF, ET, and PV exclusively in megakaryocytes and myeloid progenitor cells in contrast to undetectable IGF-2 protein in control cases. We conclude that overexpression of the IGF-2 gene is a pathogenic feature in IMF. In addition, an abundant translational and post-translational processing could explain the accumulation of IGF-2 protein detectable in all Ph- CMPD entities in contrast to non-neoplastic haematopoiesis. We conclude that IGF-2 represents a new molecular target for evaluation of underlying fundamental pathomechanisms in Ph- CMPD.

Adult↗

PubMed2004

Expression of p27 and its ubiquitin ligase subunit Skp2 in upper urinary tract transitional cell carcinoma.

OBJECTIVES: To analyze p27 and S-phase kinase-associated protein 2 (Skp2) expression in upper urinary tract transitional cell carcinoma (TCC) with respect to biologic significance. p27 (p27/kip1) is involved in cell cycle control, and loss of p27 protein expression may result in tumor development and/or progression. The association of p27 with the ubiquitin ligase subunit Skp2 targets p27 for degradation. METHODS: A total of 53 upper urinary tract TCC specimens were investigated immunohistochemically using a tissue microarray technique. The immunoreactivity of p27 and Skp2 was analyzed with respect to associations with pT stage, grade, and prognosis. RESULTS: Non-neoplastic renal tissue showed p27 immunoreactivity in tubule epithelium and pelvic urothelium, but lacked immunoreactivity for Skp2. In the TCC specimens, p27 immunoreactivity was noted in 47 (89%) of 53 cases. High p27 expression (50% or greater of tumor cell nuclei) tended to decrease with rising tumor stage (14 [45%] of 31 with pT1-pT2 versus 4 [18%] of 22 with pT3; P = 0.076), but was independent of tumor grade (11 [39%] of 28 grade 2 versus 7 [28%] of 25 grade 3-4; P = 0.56). Skp2 immunoreactivity was noted in 32 (60%) of 53 tumors. Skp2 expression increased with rising tumor stage (9 [41%] of 22 pT1 versus 23 [74%] of 31 pT2-pT3; P = 0.023) and tumor grade (12 [43%] of 28 grade 2 versus 20 [80%] of 25 grade 3; P = 0.043) and was associated with angioinvasion (P = 0.017). In multivariate analysis, tumor stage proved to be the only independent prognostic factor regarding disease-free survival. CONCLUSIONS: p27 and Skp2 are additional biomarkers in urogenital pathologic findings. The statistically significant association of Skp2 expression with high-grade TCC, as well as the lack of expression in non-neoplastic tissue, suggests that Skp2 could be a promising target for future cancer therapy strategies.

Adult↗

PubMed2004

Chimerism of metanephric adenoma but not of carcinoma in kidney transplants.

Recipient-derived cells integrate into renal allografts inducing organ-specific microchimerism. Circulating pluripotent progenitor cells with high plasticity for differentiation were suggested as a potential source of allograft chimerism. Whether or not these cells also contribute to tumor formation in renal transplants is unknown. We analyzed six histologically different tumors in renal allografts for the presence of recipient-derived cells. To circumvent dependency on gender mismatch, a polymerase chain reaction assay for highly polymorphic short tandem repeat marker (DNA fingerprinting) in combination with laser microdissection was applied. Pure tumor cell populations were harvested by laser microdissection after immunohistochemical (CD45/CD68) marking of contaminating leukocytes. In cases of gender mismatch (n = 2), results were confirmed by sex chromosome in situ hybridization. Two metanephric adenomas demonstrated microchimerism comprising both donor- and recipient-derived tumor cells. Two clear cell carcinomas, one transitional cell carcinoma, and one renal cortical adenoma were all of donor origin without chimerism. We conclude that except for metanephric adenomas, tumors arising in renal transplants originate completely from graft cells. The mixed derivation of metanephric adenomas indicates an incorporation of recipient-derived progenitor cells. This finding suggests that adult stem cells can assume neoplastic phenotypes.

Adenocarcinoma, Clear Cell↗

PubMed2003

Androgen and estrogen receptors in the human corpus cavernosum penis: immunohistochemical and cell culture results.

Despite the central and peripheral effects of androgens on the nervous system, the local effects of androgens in the corpus cavernosum penis and their importance for erectile function is still unclear. In this study corpus cavernosum biopsies of eight adult potent patients, aged 19-63 years, undergoing penile deviation surgery (group A) and 12 patients undergoing male-to-female transsexual surgery (group B) were immunostained for nuclear androgen and estrogen-alpha receptors. Additionally, primary corpus cavernosum endothelial cell cultures were obtained from six transsexual patients and exposed to testosterone, dihydrotestosterone, estradiol and progesterone likewise for 7 days. Total cell count was performed and cell metabolic activity was measured by a tetrazolium salt-based assay. Androgen and estrogen-alpha receptors were detected in stromal as well as in endothelial cells. Of all cell nuclei, 74.9% (SD 16.4) in group A and 63.5% (SD 17.1) in group B were positively stained for androgen receptors. The respective percentage of estrogen receptors was 11% (SD 9.5) and 21.2% (SD 12.6). An age-dependent difference in receptor distribution was not observed in either group. In the cell culture system only cultures exposed to testosterone and dihydrotestosterone showed a dose-dependent increase of cell metabolic activity compared to the cultures supplemented with estradiol and progesterone. The significant and age-independent high androgen and low estrogen-alpha receptor distribution found in both groups suggests a possible peripheral effect of androgens at the level of the corpus cavernosum penis in adult humans. This is supported by the observed effect of testosterone and dihydrotestosterone on cell count and endothelial cell metabolism in our cell culture system. The role of estrogens remains unclear.

Adult↗