Diagnostic value of MRI in a pelvic mass of prostatic origin: Part 2.
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
Jörg Hennenlotter
Publications and source records attributed to Jörg Hennenlotter.
Distorted relation between mRNA copy number and corresponding major histocompatibility complex ligand density on the cell surface.
The major histocompatibility complex (MHC) presents peptides derived from degraded cellular proteins to T-cells and is thus crucial for triggering specific immune responses against viral infections or cancer. Up to now, there has been no evidence for a correlation between levels of mRNA (the "transcriptome") and the density of MHC-peptide complexes (the "MHC ligandome") on cells. Because such dependences are of intrinsic importance for the detailed understanding of translation efficiency and protein turnover and thus for systems biology in general and for tumor immunotherapy in practical application, we quantitatively analyzed the levels of mRNA and corresponding MHC ligand densities in samples of renal cell carcinomas and their autologous normal kidney tissues. Relative quantification was carried out by gene chip analysis and by stable isotope peptide labeling, respectively. In comparing more than 270 pairs of gene expression and corresponding peptide presentation ratios, we demonstrate that there is no clear correlation (r = 0.32) between mRNA levels and corresponding MHC peptide levels in renal cell carcinoma. A significant number of peptides presented predominantly on tumor or normal tissue showed no or only minor changes in mRNA expression levels. In several cases, peptides could even be identified despite the virtual absence of the respective mRNA. Thus we conclude that a majority of epitopes from tumor-associated antigens will not be found in approaches based mainly on mRNA expression studies as mRNA expression reflects a distorted picture of the situation on the cell surface as visible for T-cells.
Amino Acid Sequence↗
Unexpected abundance of HLA class II presented peptides in primary renal cell carcinomas.
PURPOSE: To elicit a long-lasting antitumor immune response, CD8+ and CD4+ T cells should be activated. We attempted to isolate HLA-DR-presented peptides directly from dissected solid tumors, in particular from renal cell carcinoma, to identify MHC class II ligands from tumor-associated antigens (TAA) for their use in peptide-based immunotherapy. EXPERIMENTAL DESIGN: Tumor specimens were analyzed by immunohistochemical staining for their HLA class II expression. HLA class II peptides were subsequently isolated and identified by mass spectrometry. Gene expression analysis was done to detect genes overexpressed in tumor tissue. Peptides from identified TAAs were used to induce peptide-specific CD4+ T-cell responses in healthy donors and in tumor patients. RESULTS: In the absence of inflammation, expression of MHC class II molecules is mainly restricted to cells of the immune system. To our surprise, we were able to isolate and characterize hundreds of class II peptides directly from primary dissected solid tumors, especially from renal cell carcinomas, and from colorectal carcinomas and transitional cell carcinomas. Infiltrating leukocytes expressed MHC class II molecules and tumor cells, very likely under the influence of IFNgamma. Our list of identified peptides contains ligands from several TAAs, including insulin-like growth factor binding protein 3 and matrix metalloproteinase 7. The latter bound promiscuously to HLA-DR molecules and were able to elicit CD4+ T-cell responses. CONCLUSIONS: Thus, our direct approach will rapidly expand the limited number of T-helper epitopes from TAAs for their use in clinical vaccination protocols.
Antigens, Neoplasm↗
Investigations of urothelial cells seeded on commercially available small intestine submucosa.
OBJECTIVES: To examine adherence and viability of human urothelial cells seeded on commercially available small intestine submucosa (SIS) specimens under serum-free conditions. MATERIALS AND METHODS: Before seeding, SIS was either washed with incubation medium or coated with collagen A, fibronectin, or pronectin. A possible influence of SIS itself on the viability of urothelial cells was analysed with conditioned cell culture medium obtained by incubation of SIS for 24hours. In addition, untreated SIS and a setting without SIS were used as controls. Viability of urothelial cells was analysed with the WST-1 assay until day 9. Histology of seeded and unseeded SIS specimens was investigated after Papanicolaou staining. To demonstrate urothelial cell adherence on SIS, immunohistology was performed with a mixture of monoclonal AE1 and AE3 anticytokeratin antibodies. RESULTS: Urothelial cells seeded on SIS revealed no measurable cell viability. SIS-conditioned cell culture medium was cytotoxic for urothelial cells after 24 hours. Histology only demonstrated cell nuclei and no cytoplasm both in seeded and unseeded SIS specimens, thus indicating porcine DNA. Expression of the cell type-specific marker proteins AE1/AE3 could not be demonstrated. CONCLUSION: Since the commercially available SIS specimens used contained porcine DNA residues and demonstrated cytotoxic effects on urothelial cells, SIS is not suitable for in vitro construction of urothelial cell-matrix implants.
Cell Adhesion↗
Diagnostic value of MRI in a pelvic mass of prostatic origin.
We report on the case of a 55-year-old male with acute urinary retention, caused by a large pelvic mass. Contrast enhanced computed tomography showed a vascularized prostatic mass with calcifications. To rule out potential bladder and rectum infiltration and to optimize imaging prior to surgical exploration, an MRI examination including MR angiography and spectroscopy was performed. Clinical findings including intraoperative results are presented in this report in detail and correlated to the results of the state of the art magnetic resonance imaging.
Calcinosis↗
Size does matter: 1.5 Fr. stone baskets almost double irrigation flow during flexible ureteroscopy compared to 1.9 Fr. stone baskets.
With a new generation of flexible ureterorenoscopes, a new area in stone management is emerging. Limitation of vision with these new instruments is often caused by insufficient irrigation flow, especially when using instruments like stone baskets, resulting from partial obstruction of the working and irrigation channel with these instruments. Empirically, new available smaller stone baskets seem to dramatically improve irrigation and therefore vision in clinical use. The goal of this study was to show objective differences in basket diameters and flow rates in an in vitro setting. Diameters and irrigation flows in flexible ureterorenoscopes depending on different sizes of stone baskets (Fr. 1.5-1.7-1.9-2.2-2.4-3.0) and different deflections were measured. The measured diameter of the baskets varied within the first 20 cm and the true measured size varied from the manufacturer's specified size to a different extent. The new generation of 1.5 and 1.7 Fr. baskets improved irrigation flow, even compared to the smallest commonly used baskets, up to 68%. Interestingly, deflection did not influence irrigation flow. This study confirmed the subjective impression of inadequate description of relevant basket diameters as well as that of a significant improvement of irrigation flow with the newest generation of stone baskets with smaller diameters.
Calibration↗
Activation of the PKB/Akt pathway in histological benign prostatic tissue adjacent to the primary malignant lesions.
In order to evaluate the molecular heterogeneity of prostate cancer, this study examined the expression of Akt-pathway related parameters within the cancerous prostate gland. PTEN, p-Akt and p27kip1 are known to be altered in prostate cancer. Tissue samples from malignant, tumor adjacent benign and benign areas of 25 whole mounted prostate cancer specimens were processed to 583 tissue microarray cores. Immunohistochemically determined biomarker expression was correlated to the different localizations. p-Akt and p27kip1 showed increased staining in malignant tissue compared to the respective benign tissue (p < 0.01 and p < 0.05). The adjacent but histologically benign tissue had increased levels (p < 0.05 and p < 0.01), whereas no significant difference was found between the adjacent and malignant regions. A highly significant correlation of p-Akt and p27kip1 in benign tissue (p < 0.001) was lost in the adjacent areas and in the malignant tissue (p = 0.054 and p = 0.12). In tendency, PTEN expression was decreased in the malignant regions and revealed the highest staining in the adjacent zone. According to the results obtained, the expression of p-Akt and p27kip1 was increased in both the adjacent microscopically benign tissue as well as the primary tumors when compared with the histologically benign tissue specimens that served as biological control. The increased expression of PTEN indicates its regulatory function in the initial steps of a deteriorated cell cycle control as well as uncontrolled cellular proliferation, for example, which seem to be present in the normal prostatic tissue surrounding the primary malignant lesion. The addition of molecular markers to a 'classical' histopathological approach might contribute to an enhanced sensitivity of analytical approaches aimed at the detection of malignant or premalignant lesions within prostatic biopsies.
Aged↗
MAGED4-expression in renal cell carcinoma and identification of an HLA-A*25-restricted MHC class I ligand from solid tumor tissue.
MAGE derived HLA ligands have repeatedly been shown to elicit T-cell responses against tumor cells. In renal cell carcinoma (RCC), however, only few T-cell epitopes from cancer testis antigens have been described. To identify potential candidates, we applied a combined approach of microarray/qPCR expression analysis and sequencing of HLA ligands from RCC by mass spectrometry. We analyzed the expression of 21 MAGE genes in ten RCC samples and two glioblastoma samples and could identify the first MHC class I ligand NIGDEALIGRW from MAGED4 presented by HLA-A*25 on RCC solid tumor tissue. MAGED4 was expressed in 30% of RCC and both glioblastoma samples. Among the other MAGE family members only MAGEB2 and -C1 and the broadly expressed MAGED1, -D2, -F1 and -H1 were expressed in RCC. Ligands from MAGED4 could thus be interesting tumor-associated antigens in a subset of RCC, even though the identified ligand is presented by a rather rare allele.
Antigens, Neoplasm↗
Lessons to be learned from primary renal cell carcinomas: novel tumor antigens and HLA ligands for immunotherapy.
The lack of sufficient well-defined tumor-associated antigens is still a drawback on the way to a cytotoxic T-lymphocyte-based immunotherapy of renal cell carcinoma (RCC). We are trying to define a larger number of such targets by a combined approach involving HLA ligand characterization by mass spectrometry and gene expression profiling by oligonucleotide microarrays. Here, we present the results of a large-scale analysis of 13 RCC specimens. We were able to identify more than 700 peptides, mostly from self-proteins without any evident tumor association. However, some HLA ligands derived from previously known tumor antigens in RCC. In addition, gene expression profiling of tumors and a set of healthy tissues revealed novel candidate RCC-associated antigens. For several of them, we were able to characterize HLA ligands after extraction from the tumor tissue. Apart from universal RCC antigens, some proteins seem to be appropriate candidates in individual patients only. This underlines the advantage of a personalized therapeutic approach. Further analyses will contribute additional HLA ligands to this repertoire of universal as well as patient-individual tumor antigens.
Antigens, Neoplasm↗
3D proton MR spectroscopic imaging of prostate cancer using a standard spine coil at 1.5 T in clinical routine: a feasibility study.
The objective of this study was to demonstrate the feasibility of 3D proton MR spectroscopic imaging (MRSI) of the prostate using a standard spine instead of a dedicated endorectal coil at 1.5 T. Twenty-eight patients (25 with biopsy proven prostate cancers and three patients with a benign prostate hyperplasia) were examined. MRI and MRSI were conducted with commercial array surface coils at 1.5 T. Ratios of choline (Cho), creatine (Cr) and citrate (Ci) were calculated for tumour, central and peripheral zone retrospectively, based on axial T2 weighed MR images and histology reports. Prostate cancer was characterized by significantly elevated (Cho+Cr)/Ci ratio compared with non-tumourous prostate tissue. The quality of all proton MR spectra was considered to be good or acceptable in 17/28 patients (61%) and poor in 11/28 (39%) examinations. In 20/25 patients with proven malignancy (80%), MRSI was considered to be helpful for the detection of prostate cancer. In 4/25 patients with proven malignancy (16%) who underwent seed implantation, radiotherapy or hormone deprivation before MR examination spectroscopy was of poor and non-diagnostic quality. MRSI of the prostate is feasible within clinical routine using the spine array surface coil at 1.5 T. It can consequently be applied to patients even with contraindications for endorectal coils. However, spectral quality and signal-to-noise ratio is clearly inferior to 3D MRSI examinations with endorectal coils.
Adult↗
Moderate degradation does not preclude microarray analysis of small amounts of RNA.
Gene expression analysis by microarrays using small amounts of RNA is becoming more and more popular against the background of advances and increasing importance of small-sample acquisition methods like laser microdissection techniques. The quality of RNA preparations from such samples constitutes a frequent issue in this context. The aim of this study was to assess the impact of different extents of RNA degradation on the expression profile of the samples. We induced RNA degradation in human tumor and healthy tissue samples by endogeneous ribonucleases. Next, we amplified 20 ng total RNA degraded to different extents by two rounds of in vitro transcription and analyzed them using Affymetrix oligonucleotide microarrays. Expression differences for some genes were independently confirmed by real-time quantitative PCR. Our results suggest that gene expression profiles obtained from partially degraded RNA samples with still visible ribosomal bands exhibit a high degree of similarity compared to intact samples and that RNA samples of suboptimal quality might therefore still lead to meaningful results if used carefully.
Carcinoma, Renal Cell↗
Accuracy of the ImmunoCyt assay in the diagnosis of transitional cell carcinoma of the urinary bladder.
The ImmunoCyt assay (Diagnocure Inc., Québec, Canada) is a new immunocytological fluorescence test for identifying two different mucins and a high-molecular-weight glycosylated carcinoembryonic antigen (CEA) present in tumours originating from transitional epithelial cells. The test promises a higher diagnostic sensitivity in transitional cell carcinoma (TCC) of the bladder than voided urine cytology. Our study was designed to evaluate this test especially for TaG1 carcinomas, which are characterised by a low detection rate in urinary cytology. A total of 121 spontaneous urine samples of 92 patients (age range 28 to 86, mean 62.5 years) were examined. The samples were taken from patients suspected of having TCC (41 out of 121) or tumor recurrence (46 out of 121), or who were part of a follow-up protocol (34 out of 121). Cystoscopy was practiced in all patients. The ImmunoCyt test was carried out according to the manufacturer's protocol. For cytology cytospins were made from the same urine samples and stained according to the method of Papanicolaou. One hundred and thirteen specimens could be evaluated. In 87 cystoscopy and/or histology were negative. There was histological evidence of 7 pTaG1, 4 pTaG2, 8 pT1G2/G3 and 7 pT2G2/G3 TCC. As for ImmunoCyt and cytology, specificity was 83.9% and 91.9%, respectively. A combination of either test indicated 81.6% specificity. The sensitivity amounted to 38.5% and 34.6%, respectively, and the combined sensitivity to 53.8%. The sensitivity for TaG1 carcinomas was 14.3% each, for TaG2 carcinomas 25% and 50%, for T1G2/G3 carcinomas it amounted to 37.5% each, while for T2G2/G3 carcinomas it was 71.4% and 42.9%, respectively. The higher sensitivity of the ImmunoCyt test as compared to urinary cytology renders improved identification of exfoliated tumour cells in bladder cancer possible. In our study, however, the expected increase in detecting TaG1 carcinomas was not found. Because of its lower specificity, the test should only be used in combination with voided urine cytology. On account of its low sensitivity, the ImmunoCyt test cannot replace cystoscopy (with biopsy) in the diagnosis and monitoring of bladder cancer.
Adult↗
Membranous expression and prognostic implications of epidermal growth factor receptor protein in human renal cell cancer.
BACKGROUND: It has been indicated that altered expression of the epidermal growth factor receptor (EGFR) promotes the invasive and metastatic potential of a variety of human malignancies. Therefore, the aim of the present study was to determine EGFR expression in clear cell renal cell carcinomas (RCC) to evaluate its prognostic relevance for the clinical course of the disease. MATERIALS AND METHODS: EGFR protein expression, detected by immunohistochemistry and tissue microarray analysis (TMA), was investigated in a cohort of 149 randomly selected patients subjected to tumor nephrectomy for RCC. RESULTS: The tumor cells preferably exhibited a homogeneous membrane-bound reactivity for EGFR; EGFR overexpression was detected in 70 (47%) of the primary tumor specimens, but in only 12 (9%) of the benign tissue samples (p<0.0001; Fisher's t-test). Tumor-associated EGFR staining was stratified into three groups: I: low staining score (n=75, 50%); II: intense expression (n=56, 38%); and III: strong overexpression (n = 18, 12%). Strong reactivity for EGFR was identified as predicting the patients' survival both during uni- and multivariate analysis (p=0.03). Interestingly, the overall survival of the intense expression group surpassed even the low expression group (p=0.023). CONCLUSION: The observation that primary RCC specimens exhibit EGFR at higher levels when compared with benign renal parenchyma indicates its role in tumor development and progression. The availability of more refined prognostic factors would assist decision making in terms of the value of more aggressive treatment options for prognostically defined subgroups of patients. Additionally, if overexpression of EGFR identifies RCC with a more aggressive biological behavior, the latter receptor might serve as a novel target for a more effective therapeutical approach to RCC.
Carcinoma, Renal Cell↗