Manfred Ratschek

Androgen receptors frequently are expressed in breast carcinomas: potential relevance to new therapeutic strategies.

Several studies have demonstrated the biologic and therapeutic significance of estrogen and progesterone receptors (ER and PR) in breast carcinomas. The aim of the current study was to examine the presence of androgen receptors (AR) in breast carcinomas.

Loss of Complex I due to Mitochondrial DNA Mutations in Renal Oncocytoma

Purpose: Many solid tumors exhibit abnormal aerobic metabolism characterized by increased glycolytic capacity and decreased cellular respiration. Recently, mutations in the nuclear encoded mitochondrial enzymes fumarate hydratase and succinate dehydrogenase have been identified in certain tumor types, thus demonstrating a direct link between mitochondrial energy metabolism and tumorigenesis. Although mutations in the mitochondrial genome (mitochondrial DNA, mtDNA) also can affect aerobic metabolism and mtDNA alterations are frequently observed in tumor cells, evidence linking respiratory chain deficiency in a specific tumor type to a specific mtDNA mutation has been lacking. Experimental Design: To identify mitochondrial alterations in oncocytomas, we investigated the activities of respiratory chain enzymes and sequenced mtDNA in 15 renal oncocytoma tissues. Results: Here, we show that loss of respiratory chain complex I (NADH/ubiquinone oxidoreductase) is associated with renal oncocytoma. Enzymatic activity of complex I was undetectable or greatly reduced in the tumor samples (n = 15). Blue Native gel electrophoresis of the multisubunit enzyme complex revealed a lack of assembled complex I. Mutation analysis of the mtDNA showed frame-shift mutations in the genes of either subunit ND1, ND4, or ND5 of complex I in 9 of the 15 tumors. Conclusion: Our data indicate that isolated loss of complex I is a specific feature of renal oncocytoma and that this deficiency is frequently caused by somatic mtDNA mutations.

Functional magnetic resonance imaging of human renal allografts during the post-transplant period: Preliminary observations

Graft dysfunction is a common occurrence during the first weeks following renal transplantation. The current study was designed to evaluate the potential of renal magnetic resonance (MR) perfusion imaging to differentiate acute allograft rejection (AAR) from acute tubular necrosis (ATN) during the post-transplant period. Twenty-three consecutive patients with clinically suspected ATN and/or AAR and eight consecutive control patients (asymptomatic, serum creatinine concentration < 1.5 mg/dL) underwent MR perfusion imaging of the renal allograft within 64 days after transplantation. Histopathology was obtained in all cases with clinical suspicion of ATN or AAR. Sixty sequential fast gradient-recalled-echo MR images were acquired in each patient after intravenous administration of gadolinium-DTPA (0.1 mmol/kg). Histopathology revealed 6 patients with pure AAR, 4 patients with a combination of AAR and ATN, 12 patients with ATN and 1 patient with normal findings. Kidney graft recipients with normal renal function showed a moderate increase in signal intensity (SI) of the renal cortex and medulla after administration of contrast agent followed by an immediate and short decrease in SI of the medulla (biphasic medullary enhancement pattern). The increase in cortical SI of patients with AAR was significantly smaller (61 +/- 4% increase above baseline) than that measured in normal allografts (136 +/- 9% increase above baseline) (p < 0.05) and patients with ATN (129 +/- 3% increase above baseline) (p < .05). Patients with ATN had a slightly delayed and diminished cortical enhancement and an uniphasic and lesser medullary enhancement pattern compared to that observed in normal allografts (p < 0.05). A close correlation (r = 0.72) was found between serum creatinine concentration levels and changes in SI. Thus, MR imaging results and histopathology were in agreement in 22 of 23 patients (96%). MR perfusion imaging of renal allografts can be used to noninvasively differentiate ATN from AAR during the post-transplant period, and may also be helpful in cases were covert AAR is superimposing ATN during a phase of anuria. Patients with ATN can be separated from normals in the majority of cases as reflected by an uniphasic medullary enhancement pattern.

Expression of MUC1 (EMA) and E-cadherin in renal cell carcinoma: a systematic immunohistochemical analysis of 188 cases

MUC1 (epithelial membrane antigen) is a membrane-associated mucin known to interfere with both cell–cell and cell–matrix adhesions. Overexpression has been associated with poor prognosis in a variety of cancers. We investigated the expression of MUC1 (using two different antibodies, MA695 and E29) and E-cadherin in renal cell carcinomas (137 conventional, 23 chromophobe, 20 papillary, and eight unclassified tumors) with respect to diagnostic and prognostic significance using a tissue microarray technique. Immunoreactivity was correlated with histological subtype, pT-stage, and grade using the χ2 test or the Fishers exact test, respectively. Impact on disease-free survival was analyzed using the Kaplan–Meier method and the log-rank test. Immunoreactivity of more than 10% of cancer cells with MA695, E 29, and E-cadherin antibodies was found in 112/133 (84%), 86/133 (65%), and 7/131 (5%) conventional, 20/22 (91%), 19/22 (86%), and 21/22 (95%) chromophobe, 13/20 (65%), 8/20 (40%), and 3/20 (15%) papillary as well as 5/8 (63%), 5/8 (63%), and 4/8 (50%) unclassified carcinomas, respectively. The two different MUC1 antibodies yielded comparable staining results. A diffuse cytoplasmic staining pattern for MUC1 was found exclusively in chromophobe carcinomas, whereas conventional and papillary subtypes showed predominantly membranous staining (P<0.0001). Regarding papillary carcinomas, MUC1 was predominantly associated with type 1 (P=0.0001), and E-cadherin with type 2 (P=0.049) tumors. The cellular staining pattern of MUC1 in conventional tumors was related to pT-stage (P=0.002) and tumor grade (P=0.001): Low-stage (pT1/pT2) and grade (G1/G2) tumors showed a predominantly apical membranous staining, high-stage (pT3a/pT3b) and grade (G3/G4) tumors a predominantly circumferential membranous staining (with or without additional diffuse cytoplasmic immunoreactivity), which, in the conventional subtype, was associated with poor prognosis (P<0.0001). In conclusion, MUC1 and E-cadherin are diagnostically and prognostically useful markers in renal tumor pathology, especially when cellular staining patterns are considered.

Are heterogenous results of EGFR immunoreactivity in renal cell carcinoma related to non-standardised criteria for staining evaluation?

Aims: To assess whether heterogeneity of epidermal growth factor receptor (EGFR) immunoreactivity in renal cell carcinoma (RCC) is related to non-standardised criteria for staining evaluation. Methods: EGFR expression was investigated in 132 primary and 55 metastatic conventional RCCs using a tissue microarray technique. Results: Overall, membranous and/or cytoplasmic EGFR immunostaining was present in 123 of 132 (93%) primary and 49 of 53 (92%) metastatic RCCs, with extensive immunoreactivity (> 50% of tumour cells) in 110 of 132 (83%) primary tumours and 39 of 53 (73%) metastases. Cytoplasmic staining was associated with high tumour stage and high tumour grade. In addition, strong membranous staining (score 3+) prevailed in high grade RCCs. Cytoplasmic immunostaining was associated with an unfavourable prognosis, whereas overall (cytoplasmic and membranous) immunoreactivity and intensity of membranous staining were not. Conclusions: Different methods of immunohistochemical evaluation led to different results, strengthening the need for standardisation, especially against a background of rapidly evolving EGFR targeted cancer treatment strategies.

CD10 is a diagnostic and prognostic marker in renal malignancies

Aims:  To determine the diagnostic and prognostic value of CD10 immunoreactivity in renal cell carcinomas (RCCs) and transitional cell carcinomas (TCCs).

Gangliocytes in neuroblastic tumors express alarin, a novel peptide derived by differential splicing of the galanin-like peptide gene

In neuroblastic tumors a relationship of differentiation of the tumor to galanin receptor expression and antip roliferative and apoptotic effects upon activation of galanin receptors in neuroblastoma cells was reported. To elucidate the expression of other components of the galanin peptide family in neuroblastic tumors, RT-PCR analysis of a variety of human neuroblastic tumor tissues was performed. Ganglioneuroma tissues revealed the presence of a splice variant of the galanin-like peptide (GALP) mRNA, which results in exclusion of exon 3 and a frame shift after the signal peptide sequence of GALP. This generates a peptide of 25 amino acids, which we have termed alarin because of the N-terminal alanine and the C-terminal serine. The novel neuropeptide alarin does not reveal significant homology to other peptides. Immunohistochemistry with antibodies directed against synthetic alarin peptide detected specific cytoplasmic granular staining in ganglia of human ganglioneuroma and ganglioneuroblastoma, as well as differentiated tumor cells of neuroblastoma tissues. Undifferentiated neuroblasts of these tumor tissues did not show alarin-like immunoreactivity and alarin-specific mRNA. Our findings indicate that alarin expression is a feature of ganglionic differentiation in neuroblastic tumor tissues.

P63 Immunoreactivity Distinguishes Upper Urinary Tract Transitional-cell Carcinoma and Renal-cell Carcinoma Even in Poorly Differentiated Tumors

P63 is essential for the differentiation of normal urothelium and is also expressed in transitional cell carcinoma (TCC) of the bladder. We investigated p63 immunoreactivity in upper urinary tract TCC (n = 53) and in renal-cell carcinoma (RCC; n = 188) using a tissue microarray technique. P63 expression was detected in 51/53 (96.2%) TCCs, showing decreased expression in high-stage (pT1 and pT2 100%; pT3 90.9%) and poorly differentiated (G1 and G2 100%; G3 92%) tumors. All RCCs were negative for p63. P63 proved to be a helpful tool, even in poorly differentiated and undifferentiated renal malignancies, to distinguish TCC from RCC.

Keratin immunohistochemistry in renal cell carcinoma subtypes and renal oncocytomas: a systematic analysis of 233 tumors

Keratin immunohistochemistry represents a widely applied differential diagnostic tool in surgical pathology. To investigate the value of keratin subtyping for the diagnosis among histological subtypes of renal cell carcinoma and oncocytomas, we performed a detailed immunohistochemical study, applying 22 different monoclonal keratin antibodies on a large series of 233 renal tumors [125 conventional, 22 chromophobe, and 20 papillary (12 type-1, 8 type-2 tumors) cancers and 66 oncocytomas] using a tissue microarray technique. Immunoreactivity for keratin 7, 8, 18, and 19 was present in all tumor entities, albeit in varying quantities. With antibodies directed against keratins 8 and 18, oncocytomas showed a distinct perinuclear and punctate dot-like pattern, which was not observed in renal cancer specimens. The only tumors showing immunoreactivity for keratin 20 were two type-2 papillary cancers. All other monospecific keratin antibodies yielded consistently negative results. Overall, in contrast to some recent publications, keratin subtyping generally appeared to be of additional value only for the differentiation of renal epithelial tumors. Hence, with respect to differential diagnostic value, Hale’s colloidal iron stain and vimentin immunostaining are still the most useful tools in renal tumor pathology.

Allopurinol reduces bacterial translocation, intestinal mucosal lipid peroxidation, and neutrophil-derived myeloperoxidase activity in chronic portal hypertensive and common bile duct-ligated growing rats.

Bacterial translocation (BT) from the gastrointestinal tract has been thought to play a role in the pathogenesis of septic complications in patients with chronic portal hypertension (PH) and obstructive jaundice. The purpose of this study was to investigate the incidence of BT and to assess the role of intestinal mucosal malondialdehyde (MDA) levels as an indicator of lipid peroxidation and polymorphonuclear neutrophil-derived myeloperoxidase (MPO) in chronic portal hypertensive and common bile duct-ligated rats. Twenty male rats were subjected to sham laparotomy (SL), 20 rats to calibrated portal vein constriction (PH), 20 rats to common bile duct ligation (CBDL), and 10 rats served as a nonoperated control group (NOP). After 4 wk, 10 animals of each operated group received 50 mg/kg allopurinol intraperitoneally, at 24 h, and again 2 h prior to estimation of BT, intestinal mucosal MDA, and MPO activities. In the NOP and SL groups, BT to the mesenteric lymph nodes (MLN) and spleen was present. In PH and in CBDL rats, BT to liver, portal vein, peritoneum, and caval vein occurred. Allopurinol treatment attenuated the frequence of BT in PH and decreased BT in CBDL rats significantly (p< 0.05). Ileal mucosal MDA levels (nanomoles/g) in untreated rats increased from 45,1 ± 7.9 in SL to 98.2 ± 9.1 in PH and to 102.2 ± 11 in CBDL rats (p < 0.01). In the allopurinol groups the increase of MDA to 49.1 ± 1.3 in PH, and 66.2 ± 2.2 in CBDL was significantly lower (p < 0.01). MPO activity (units/g) in the ileal mucosa increased in untreated rats from 319 ± 129 after SL to 866± 104 after PH and to 1016 ± 104 after CBDL (p < 0.01). Allopurinol significantly attenuated MPO activity to 369 ± 44 in PH, and to 372 ± 60 in CBDL animals (p < 0.01). In PH and CBDL rats significant BT, intestinal mucosal lipid peroxidation, and polymorphonuclear neutrophil-derived MPO activity occurred. Allopurinol reduced BT and improved intestinal mucosal MDA and MPO activities, suggesting that there might be an association between BT and intestinal mucosal lipid peroxidation.