[T1 bladder cancer: role of documentation for bladder tumor findings and targeted second resection]

BACKGROUND

For control resection of T1 bladder tumors an exact relocalization of the previously infiltrating tumor spread can be complicated by postreactive alterations, multiple scar tissue or change of surgeons. In this study the results of control transurethral resection of the bladder (TURB) after T1 high grade bladder tumors with the focus on localization and importance of standardized exact documentation were analyzed.

PATIENTS AND METHODS

From July to February 2012 a control resection was performed in 167 patients due to a T1 high grade bladder cancer. The rates of residual tumor tissue and localization were investigated with standardized tumor documentation.

RESULTS

Out of 167 patients with T1 bladder cancer who underwent a control resection tumor tissue was found in 58.1 % (97 out of 167) and in 85.6 % (83 out of 97) the primary site was affected (41.2 % only at primary site and 44.3 % additionally at other locations). In 11 patients (11.3 %) residual tumor tissue at the initial site was only detected histologically.

CONCLUSIONS

Our results indicate that T1 high grade bladder cancers show a relevant rate of residual tumor tissue at control resection which confirms the clinical guidelines of the European Association of Urology (EAU) on mandatory resection. In most cases the primary tumor site is affected. The standardized bladder tumor documetation allows well-directed control resection also in patients with multiple scars and post-TUR alterations, even when performed by a different surgeon.

[Impact of operator experience on TURB of high-grade non-muscle-invasive bladder cancer--analysis of 254 second resections at a university teaching hospital]

INTRODUCTION

In departments with urological training of residents, part of the TURB procedures are performed as "teaching surgery". Does resection quality and early recurrence depend on the operator's experience?

PATIENTS AND METHODS

From July 2007 to February 2012 254 second resections (TURB) after Ta high-grade and T1 high-grade bladder tumours were performed at our institution. The surgeons were stratified into "junior residents" (first and second year of training), "experienced residents" (3rd-5th year of training), board certified urologists, consultants and chief surgeons. We analysed the risk of recurrence at second resection and characteristics of the initial TURB.

RESULTS

87 patients presented with a Ta high-grade tumour (34.3%) and 167 had a T1 high-grade lesion (67.7%). Most TURBs were performed by "experienced residents" (3rd-5th year) and the chief of department. The recurrence rate at second resection was 52.4%. A significant association with the recurrence rate was shown for the number of initial tumours, size and T-stage. No association was found for the training level of the surgeon. Additionally, there was no different detrusor rate for the surgeons, as a parameter for a correct, muscle-deep TURB. A bias that surgeons in training had more favourable tumours (solitary, less than 3 cm) could be excluded.

CONCLUSIONS

In our data detrusor rate and recurrence risk at second resection are independent of the surgeon's experience. The results of "teaching-TURBs" are not inferior compared to TURBs performed by board certified urologists or consultants under the conditions of undisturbed communication and personal supervision.

[T1 high-grade bladder cancer - value of second operation with prognostuic parameters of first operation: analysis of 167 cases]

We have evaluated the results of second transurethral resections of the bladder (TURB) after T1 high-grade bladder cancer over a 4.5-year period.From July 2007 to February 2012, 2172 TURB procedures were performed at our institution, of which 1130 were initial resections owing to primary tumour or relapse. Of these, 258 revealed T1 high-grade bladder cancer, and here we investigated tumour characteristics of the initial TURB and results of the second resection.The incidence of T1 high-grade tumours was 22.8% (N=258). Of 167 patients who underwent a second resection, tumour was found in 58.1% (97 of 167). Tumours were mostly multifocal (61.9%) and smaller than 3 cm (69.1%). Histology of the second resection revealed Ta low-grade in 8.4%, Ta high-grade in 16.2%, T1 high-grade in 19.8% and an upstaging to T2 and more in 6.6%. A significant association with the recurrence rate was found for the number of tumours at initial TURB: patients with multiple tumours at initial TURB had a recurrence rate of 69.0% compared with only 46.3% of patients with solitary tumour. For tumour-size and detrusor muscle in specimen a non-significant association was shown.T1 high-grade bladder cancers show a relevant rate of tumour at second TURB which confirms the clinical guidelines of the EAU. A significant association for a tumour-free second TURB in our data was shown for solitary tumours. A non-significant association was shown for tumour-size and when detrusor muscle was present in the specimen. Currently there is no data to determine the best time interval before second resection.

Two papillary renal cell carcinomas of different origin following renal transplantation (Case report)

Papillary renal cell carcinoma (PRCC) is a rare malignant tumor entity compared to common clear cell renal carcinoma. In the present study, we report a patient who was diagnosed with PRCC twice and successfully treated each time following renal transplantation. The first PRCC was located in the left native kidney two years following transplantation, and the second PRCC was diagnosed in the allograft 13 years following transplantation. The two tumors were completely removed by surgery in stage I of the disease with sufficient conservation of the allograft function. Notably, the tumors had a different origin as indicated by the microsatellite analysis, which reflects the exceptional course of the case. Risk factors for PRCC were identified in our patient. We concluded that high-risk candidates for malignancies in renal transplant recipients should receive shorter ultrasonic screening intervals, which may facilitate early tumor detection and improve outcome rates.

Retroperitoneal tumours: the pathologist's view

Retroperitoneal lesions/sarcomas are rare. Diagnosis is difficult and needs special methods. Diagnosis and Treatment is an interdisciplinary process. Molecular Diagnostics will become more and more necessary in the future.

Evaluation of EGFR gene copy number as a predictive biomarker for the efficacy of cetuximab in combination with chemotherapy in the first-line treatment of recurrent and/or metastatic squamous cell carcinoma of the head and neck: EXTREME study

Background: The phase III EXTREME study demonstrated that combining cetuximab with platinum/5-fluorouracil (5-FU) significantly improved overall survival in the first-line treatment of patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) compared with platinum/5-FU alone. The aim of this investigation was to evaluate elevated tumor EGFR gene copy number as a predictive biomarker in EXTREME study patients.

Patients and methods: Dual-color FISH was used to determine absolute and relative EGFR copy number. Models of differing stringencies were used to score and investigate whether increased copy number was predictive for the activity of cetuximab plus platinum/5-FU.

Results: Tumors from 312 of 442 patients (71%) were evaluable by FISH and met the criteria for statistical analysis. A moderate increase in EGFR copy number was common, with high-level amplification of the gene occurring in a small fraction of tumors (∼11%). Considering each of the models tested, no association of EGFR copy number with overall survival, progression-free survival or best overall response was found for patients treated with cetuximab plus platinum/5-FU.

Conclusion: Tumor EGFR copy number is not a predictive biomarker for the efficacy of cetuximab plus platinum/5-FU as first-line therapy for patients with R/M SCCHN.

[Renal cell carcinomas. Pathomorphologic diagnosis in the light of modern pharmacotherapy]

Renal carcinomas have been classified with increasing accuracy in recent years and new sub-groups have been assigned, which, due to their distinct development pathways, carry varying prognoses and require specific treatment approaches. A range of antibodies are available for their immunohistochemical classification. Identifying a gene defect--mutation, deletion, trisomies and monosomies, oncogene activation--enables the application of targeted therapy, e.g. using antibodies or tyrosine kinase inhibitors in signaling pathways, among others. Renal carcinoma diagnosis by the pathologist is taking on a particularly important role.

Outcome prediction to cetuximab in advanced colorectal cancer: Analysis of EGFR and HER2 gene copy number by fluorescence in situ hybridization

10569

Background: Recent studies suggest that increased epidermal growth factor receptor (EGFR) gene copy number assessed by in situ hybridization predicts response to cetuximab in patients (pts) with advanced colorectal cancer (mCRC). Additionally, preclinical data indicate that HER2, a member of the EGFR family, can modulate the efficacy of anti-EGFR monoclonal antibodies. Methods: We assessed EGFR and HER2 gene copies by fluorescent in situ hybridization (FISH) on paraffin-embedded samples from 70 pts with mCRC treated with cetuximab alone or with irinotecan. FISH was assessed either on primary tumors (55 pts) or on metastases (15 pts) according to two parameters: the absolute copy number of genes and chromosome (chr) centromeres, and their frequencies in 100 tumor cells. A sensitivity analysis was performed and fitted to outcome data in an attempt to define relevant cutoffs. EGFR protein expression by immunohistochemistry was deemed positive with =10% tumor cells being stained. Multiple paired samples originating from different tumor sources were analyzed whenever available (27 pts). Results: The overall response rate was 25%. Prevalent FISH patterns were disomy (8%) and balanced polysomy (90%) for EGFR gene and chr 7. EGFR amplification was seen in two pts (2%), of which only one responded. HER2 amplification was seen in two of 54 pts (3%), both experiencing stable disease. Average EGFR copies and frequency of tumor cells with >2 copies respectively ranged from 1.6 to 4.0 and from 10% to 90%, thus reflecting a substantial tumor heterogeneity. Despite assessing multiple centile cutoffs of gene copy numbers and their frequencies in tumor cells, we found no association between EGFR and HER2 copy numbers and objective response, time to progression, and overall survival. Analysis of paired samples did not improve the predictive value of EGFR copies by FISH. Excluding EGFR amplification, associated to a strong (3+) EGFR staining, we found no correlation between EGFR copy number and protein expression. Conclusions: Neither EGFR nor HER2 copies by FISH, nor EGFR expression, are predictors of outcome in mCRC pts treated with cetuximab. FISH might still play a role in screening EGFR and HER2 amplification, but cost-effectiveness is debatable.

[Table: see text]

[Villous adenoma of the renal pelvis and ureter]

Villous adenomas of the urinary tract are extremely rare tumours belonging to the adenoepithelial metaplasias. They can be associated with other neoplasias, especially with carcinomas. We describe the case of an 85-year-old female patient suffering from a villous adenoma of the renal pelvis and ureter.

Comparative expression profiling with kinetic RT-PCR in paired fresh frozen and archived formalin-fixed, paraffin-embedded renal cell cancer and normal tissue

4606

Background: It would be a substantial progress if gene expression of tumor markers could be accurately analyzed on RNA isolated from formalin fixed paraffin-embedded (FFPE) tumor tissue which is routinely collected. To prove equivalence between fresh frozen and archived FFPE tissue RNA profiles, we quantified 12 different genes with kinetic RT-PCR in renal tumor and paired adjacent normal tissue archived for 8–14 years. Methods: We had access to a set of 32 clear cell renal cell cancers and its adjacent normal tissue (HELIOS Clinic, Wuppertal). Each sample existed as a FFPE tissue block and as paired fresh frozen tissue both stored over 8–14 years at RT or -80oC, respectively. RNA from FFPE tissue was isolated with a Bayer HealthCare internal silica bead-based isolation method. Each sample was analyzed with kinetic one-step RT-PCR for the gene expression of 3 housekeepers (RPL37A, GAPDH, CD63) and 9 candidate genes (EGFR, Her2/neu, Her3, Her4, EGF, TGFα, NRG1, HIF1α, VEGFα). Results: The comparative FFPE/fresh frozen expression data showed a good correlation over all data points (r = 0.87 for Ct values) and the tumor specific up- and down regulation of EGFR family genes and its ligands could be detected in both tissue types equally. We could clearly demonstrate the tumor specific up-regulation of EGFR (2-fold), TGFα (2-fold), VEGFα (4-fold) and down-regulation of EGF (60-fold), Her2/neu (4-fold), Her3 (2-fold) and Her4 (30-fold) in renal cell cancer for both tissue entities (fixed and fresh frozen). In addition a 3-dimensional Principal Component Analysis completely separated the renal tumor population from paired normal tissue in both tissue entities based on the differential gene expression. Conclusions: Here we demonstrate that a small set of genes from the EGFR family and their ligands is specifically up-/down-regulated in renal cell cancer tissue and therefore can be clearly distinguished from normal renal tissue. Furthermore, these data prove that the internal Bayer HealthCare isolation/kinetic RT-PCR detection protocol for RNA from FFPE tissue allows accurate retrospective expression profiling and validation of marker panels in archived tissue material stored for more than a decade.

[Table: see text]

[Choristoma in the vocal fold]

Choristoma in the larynx is rare and related to thyroid or glial tissue. The manifestation of salivary gland tissue in the larynx has not been reported to date. We present the case of an 80 year old male complaining of hoarseness and productive coughing. A left side tumourous swelling was seen in the larynx with intact vocal cord mobility. Using microlaryngoscopy the mass was resected without any intra- or postoperative problems. Histologically, a choristoma-heterotopic salivary gland tissue in the muscle and fat tissue--was found. The mucosa was intact and there were no signs of malignancy. Differential diagnosis of such masses in the larynx include benign lesions as well as specific infections, e.g. tuberculosis, sarcoidosis, amyloidosis and Wegener's granulomatosis. Especially in non-smokers, sarcoma, lymphoma and melanoma should be separated from the frequent squamous cell carcinoma of the laryngeal tissue. In rare cases, heterotopic tissue can mimic a tumourous mass. Intralaryngeal resection is the therapy of choice and should be recommended to the patient.

Down-Regulation of HLA Class I Antigen Processing Molecules: An Immune Escape Mechanism of Renal Cell Carcinoma?

PURPOSE

Proper HLA class I antigen processing and presentation is a prerequisite for the recognition of tumor cells by cytotoxic T lymphocytes. To date there exist only limited information on the expression of components of the HLA class I associated antigen processing machinery (APM) in surgically removed benign renal cell adenoma, and primary and metastatic renal cell carcinoma (RCC).

MATERIALS AND METHODS

A total of 133 primary RCCs of different subtypes, 10 renal cell adenoma biopsies, 32 matched metastases of different localization and autologous normal kidney epithelium were immunohistochemically analyzed for the expression of HLA class I antigens, low molecular weight protein (LMP)2 and LMP7, the transporter associated with antigen processing subunit (TAP1) and beta 2-microglobulin (beta 2-m).

RESULTS

Normal kidney tissue showed strong cytoplasmic staining intensity for LMP2, LMP7 and TAP1, whereas beta 2-m and HLA class I heavy chains were detected on the cell surface. A low frequency of HLA class I HC and beta 2-m down-regulation was found in RCC. In contrast, primary RCC and metastases showed a high frequency of a total lack of heterogeneous TAP1, LMP2 and LMP7 expression, which was often coordinately regulated. APM component deficiencies were associated with RCC subtypes but not with tumor grading and staging.

CONCLUSIONS

HLA class I APM component abnormalities appear to represent an immune escape mechanism of RCC. This finding emphasizes the need to evaluate the integrity and expression of these molecules in patients with RCC, especially in those selected for treatment with T-cell based immunotherapy.

Characterization of human lymphocyte antigen class I antigen-processing machinery defects in renal cell carcinoma lesions with special emphasis on transporter-associated with antigen-processing down-regulation

The HLA class I antigen-processing machinery (APM) plays a crucial role in the generation of peptides from endogenously synthesized proteins and in their presentation to cytotoxic T lymphocytes. The potential role of defects of APM components in immune escape mechanisms used by malignant cells has prompted us to analyze their expression in renal cell carcinoma (RCC) lesions with special emphasis on TAP because of its critical role in the loading of HLA class I antigens with peptides. Immunohistochemical staining of 51 formalin-fixed RCC lesions and autologous normal renal epithelium detected transporter associated with antigen processing (TAP)1 and tapasin deficiencies in 63 and 80% of the tumor lesions. Impaired low molecular weight protein (LMP)2 and LMP7 expression was found in 73 and 33% of the RCC lesions analyzed, respectively. In contrast to the high frequency of APM component down-regulation, HLA class I heavy chain and beta(2)-microglobulin defects were detected in only 12 and 10% of the lesions, respectively. Concomitant TAP1 and LMP2 deficiencies were found in approximately 57% of RCC lesions, whereas a coordinated down-regulation of all APM components occurred only in 5% of the tumor specimens analyzed. The presence of APM defects was independent of tumor stage and grade but varied significantly among the RCC subtypes. TAP abnormalities do not appear to be attributable to structural alterations because no mutations in TAP1 were detected in TAP1-deficient RCC lesions. These data suggest that TAP defects in RCC lesions are caused by regulatory abnormalities. Therefore, T-cell-based immunotherapy may benefit from the administration of cytokines that up-regulate TAP expression.

Low-grade tubular-mucinous renal neoplasms: morphologic, immunohistochemical, and genetic features

The current classification system of renal tumors is based on morphologic criteria, as supported by genetic findings. We present a group of previously unclassified tumors with similar morphologic and genetic features, suggesting a new entity within renal neoplasms. Seven renal tumors from five patients (ages 31-67 years) were analyzed. All cases were stained with periodic acid-Schiff, Hale's colloidal iron (HCI), and Alcian blue (AB) at pH 2.5/1.0 with and without hyaluronidase (HA) digestion. Immunohistochemical (IHC) stains were performed for CK8, CK18, CK19, vimentin, villin, Tamm-Horsfall protein (THP), renal cell carcinoma marker (RCC), epithelial membrane antigen (EMA), ulex europaeus agglutinin (UEA-1), soy bean agglutinin (SBA), peanut agglutinin (PNA), and MIB-1. Comparative genomic hybridization (CGH) and loss of heterozygosity (LOH) studies were performed on all cases. All tumors showed circumscribed growth, a tubular growth pattern with focal solid areas, no significant nuclear atypia and absence of necrosis, desmoplasia, or inflammation. Abundant extracellular mucin was present. Immunohistochemistry stains support collecting duct origin (EMA+, PNA+, SBA+/-, CK 8/18/19+, vimentin+/-, UEA-1-, RCC-, villin-, THP-). The proliferative rate was low (<1%). CGH showed multiple consistent chromosomal losses (-1,-4, -6, -8, -9, -13, -14, -15, -22). Clinical outcome was favorable, with recurrences but no known distant metastases or death of disease. These findings are distinct from all previously classified renal neoplasms. Our data suggest the presence of a unique tumor entity within tumors of probable collecting duct origin: tubular-mucinous renal tumors of low malignant potential.

[Molecular genetic changes in renal cell carcinomas]

Over the last decade several genetic alterations involved in the pathogenesis and progression of renal cell carcinoma have been identified. These findings will have a wide implication for the diagnosis and management of renal cell carcinomas. This review provides a discussion of general principles of tumor development as well as the specific mechanisms underlying renal carcinogenesis.

Successful adenovirus-mediated wild-type p53 gene transfer in patients with bladder cancer by intravesical vector instillation

PURPOSE

To study safety, feasibility, and biologic activity of adenovirus-mediated p53 gene transfer in patients with bladder cancer.

PATIENTS AND METHODS

Twelve patients with histologically confirmed bladder cancer scheduled for cystectomy were treated on day 1 with a single intratumoral injection of SCH 58500 (rAd/p53) at cystoscopy at one dose level (7.5 x 10(11) particles) or a single intravesical instillation of SCH 58500 with a transduction-enhancing agent (Big CHAP) at three dose levels (7.5 x 10(11) to 7.5 x 10(13) particles). Cystectomies were performed in 11 patients on day 3, and transgene expression, vector distribution, and biologic markers of transgene activity were assessed by molecular and immunohistochemical methods in tumors and normal bladder samples.

RESULTS

Specific transgene expression was detected in tissues from seven of eight assessable patients treated with intravesical instillation of SCH 58500 but in none of three assessable patients treated with intratumoral injection of SCH 58500. Induction of RNA and protein expression of the p53 target gene p21/WAF1 was demonstrated in samples from patients treated with SCH 58500 instillation at higher dose levels. Distribution studies after intravesical instillation of SCH 58500 revealed both high transduction efficacy and vector penetration throughout the whole urothelium and into submucosal tumor cells. No dose-limiting toxicity was observed, and side effects were local and of transient nature.

CONCLUSION

Intravesical instillation of SCH 58500 combined with a transduction-enhancing agent is safe, feasible, and biologically active in patients with bladder cancer. Studies to evaluate the clinical efficacy of this treatment in patients with localized high-risk bladder cancer are warranted.

Successful adenovirus-mediated wild-type p53 gene transfer in patients with bladder cancer by intravesical vector instillation

PURPOSE

To study safety, feasibility, and biologic activity of adenovirus-mediated p53 gene transfer in patients with bladder cancer.

PATIENTS AND METHODS

Twelve patients with histologically confirmed bladder cancer scheduled for cystectomy were treated on day 1 with a single intratumoral injection of SCH 58500 (rAd/p53) at cystoscopy at one dose level (7.5 x 10(11) particles) or a single intravesical instillation of SCH 58500 with a transduction-enhancing agent (Big CHAP) at three dose levels (7.5 x 10(11) to 7.5 x 10(13) particles). Cystectomies were performed in 11 patients on day 3, and transgene expression, vector distribution, and biologic markers of transgene activity were assessed by molecular and immunohistochemical methods in tumors and normal bladder samples.

RESULTS

Specific transgene expression was detected in tissues from seven of eight assessable patients treated with intravesical instillation of SCH 58500 but in none of three assessable patients treated with intratumoral injection of SCH 58500. Induction of RNA and protein expression of the p53 target gene p21/WAF1 was demonstrated in samples from patients treated with SCH 58500 instillation at higher dose levels. Distribution studies after intravesical instillation of SCH 58500 revealed both high transduction efficacy and vector penetration throughout the whole urothelium and into submucosal tumor cells. No dose-limiting toxicity was observed, and side effects were local and of transient nature.

CONCLUSION

Intravesical instillation of SCH 58500 combined with a transduction-enhancing agent is safe, feasible, and biologically active in patients with bladder cancer. Studies to evaluate the clinical efficacy of this treatment in patients with localized high-risk bladder cancer are warranted.

Alpha-fetoprotein-producing renal cell carcinoma

Alpha-fetoprotein (AFP) is recognized as a tumor marker of yolk sac tumors, liver cancer and some other cancers of the digestive organs. Renal cell carcinoma (RCC) producing AFP is a rare entity. A case of AFP-producing RCC with solitary bone metastasis, but without liver involvement, is reported. The stain specific to AFP proved the presence of AFP in the cytoplasms of more cells of the renal tumors. Additionally, the other published cases are reviewed. These cases indicate that mesoderm-originating malignant tumors such as RCCs can produce AFP in some situations. So, AFP is probably more universal than believed, although it is generally a popular and useful tumor marker for hepatocellular carcinomas and yolk sac tumors.

[Fournier gangrene as a rare complication after stapler hemorrhoidectomy. Case report and review of the literature]

Fournier's gangrene is a well known often fatal fasziitis of the pelvic floor following ano-rectal, urologic and gynecologic infections. Although rarely it is described as a complication of operative anal procedures and predisposing factors such as diabetes, alcoholism, immune-defects and consumptive diseases. To our knowledge the described case of a lethal outcome after staplerhemorrhoidectomy is the first one reported in literature.

Genomic imbalances in 61 renal cancers from the proximal tubulus detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) has been applied to characterize 61 primary renal cell carcinomas derived histogenetically from the proximal tubulus. The tumor samples comprised 46 clear-cell renal cell carcinomas (ccRCCs) and 15 papillary renal cell carcinomas (pRCCs). Changes in the copy number of entire chromosomes or subregions were detected in 56 tumors (92%). In ccRCCs, losses of chromosome 3 or 3p (63%); 14q (30%); 9 (26%); 1 and 6 or 6q (17% each); 4 and 8 or 8p (15% each); 22 (11%); 2 or 2q and 19 (9% each); 7q, 10, 16, 17p, 18, and Y (7% each); and 5, 11, 13, 15, and 21 (4% each) were detected. Most frequent genomic gains in ccRCC were found on chromosome 5 (63%); 7 (35%); 1 or 1q (33%); 2q (24%); 8 or 8q, 12, and 20 (20% each); 3q (17%); 16 (15%); 19 (13%); 6 and 17 or 17q (11% each); and 4, 10, 11, 21, and Y (9% each). In pRCCs, gains in the copy number of chromosomes 7 and 17 (7/15, each) and 16 and 20 (6/15, each) were frequent. One pRCC showed amplification of subchromosome regions 2q22-->q33, 16q, 17q and the entire X chromosome. In pRCC, losses were less frequently seen than gains. Losses of chromosomes 1, 14, 15, and Y (3/15 each) and 2, 4, 6, and 13 (2/15 each) were observed. In ccRCCs, statistical evaluation revealed significant correlations of chromosomal imbalances with tumor stage and grade, i.e., a gain in copy number of chromosome 5 correlated positively with low tumor grade, whereas a gain of chromosomes 10 and 17 correlated positively with high tumor grade. Furthermore, loss of chromosome 4 correlated positively with high tumor stage.

Replication-defective recombinant Semliki Forest virus encoding GM-CSF as a vector system for rapid and facile generation of autologous human tumor cell vaccines

This paper describes the production of recombinant Semliki Forest virus encoding murine or human granulocyte-macrophage colony-stimulating factor (GM-CSF) and the capacity of these vectors to transduce murine and human tumor cells ex vivo. High-titer stocks (up to 3 x 10(9) particles/ml) of conditionally infective, replication-defective, recombinant SFV particles were generated using the SFV Helper-2 system. It is shown that the recombinant SFV/GM-CSF virus, as well as recombinant SFV carrying the beta-galactosidase reporter gene, efficiently transduce both murine tumor cell lines as well as primary human renal carcinoma cells. Using ELISA's specific for GM-CSF, levels of GM-CSF production by the cells were determined. Levels of murine GM-CSF (mGM-CSF) produced by SFV/mGM-CSF transduced renal cell cancer cultures were equal to or higher than corresponding levels reported in the literature after transduction of similar renal carcinoma cell cultures using a retroviral vector system. The biological activity of GM-CSF was demonstrated by using cells which are dependent on GM-CSF for growth and by using primary bone marrow cells. All the transduced cell cultures (including the human renal cell carcinoma samples) produced GM-CSF for up to at least 4 days after transduction. The results imply that the recombinant SFV system can be used for rapid and facile preparation of autologous cancer cell vaccines.

VHL and FHIT locus loss of heterozygosity is common in all renal cancer morphotypes but differs in pattern and prognostic significance

Deletions involving 3p are believed to be typical for conventional (clear cell) renal cell carcinoma (cRCC), with confirmed and suspected targets being the VHL and FHIT tumor suppressor genes, respectively. By contrast, 3p deletions are felt to be rare in papillary RCC (pRCC) and chromophobe RCC (chRCC); however, this belief is based on relatively scant data. In particular, 3p14.2 deletions, possibly resulting in FHIT inactivation, have been rarely studied in pRCC or chRCC even though they may be relevant in early renal tumorigenesis. We therefore examined 3p deletion rates and patterns in pRCC and chRCC with particular attention to 3p14.2. We examined 16 chRCCs and 27 pRCCs for loss of heterozygosity (LOH) at 3p25-26 and 3p14.2 using 13 well-mapped microsatellite markers. Those pRCC with LOH at 3p25-26 were also screened for VHL gene mutations. The results were correlated with tumor histology and patient outcome and compared with data we had obtained previously on cRCC. We found similar overall 3p LOH rates in pRCC (59%), chRCC (86.6%), and cRCC (75.8%). In pRCC and chRCC, LOH at 3p25-26 was more common than at 3p14.2, whereas the converse was true for cRCC. In the pRCC with 3p25-26 LOH, we confirmed that this was not associated with mutations of the VHL gene. At 3p14.2, LOH rates of pRCC were lower than those of cRCC and chRCC (p<0.02). All morphotypes showed a predominately interstitial LOH pattern, which was most pronounced in the 3p14.2 region in cRCC. 3p LOH in chRCC was associated with improved patient outcome, mirroring our previous cRCC data. We conclude that 3p LOH is a universal phenomenon in RCC, but has different underlying mechanisms, molecular targets, and implications in the different morphotypes, although FHIT inactivation may play a role in both cRCC and chRCC tumorigenesis.

HER-2/neu is expressed in human renal cell carcinoma at heterogeneous levels independently of tumor grading and staging and can be recognized by HLA-A2.1-restricted cytotoxic T lymphocytes

The HER-2/neu oncoprotein, a 185 kDa membrane-associated tyrosine kinase with extensive homology to the epidermal growth factor receptor (EGF-R), is overexpressed in breast and ovarian carcinomas. Its overexpression is closely associated with poor prognosis in the course of disease. Here we demonstrate HER-2/neu overexpression in both established cell lines and biopsy material obtained from renal epithelial tumors. Immunohistochemical analysis of human kidney tumor lesions using 2 HER-2/neu-specific antibodies revealed HER-2/neu expression in more than 40% of primary epithelial renal tumors and more than 30% of primary renal cell carcinoma (RCC) specimens. A distinctive HER-2/neu expression pattern was found in different subtypes of kidney tumors with the highest frequency in chromophilic and chromophobic RCC, but neither associated with disease stage nor tumor grade. Eight of 10 RCC cell lines expressed significant levels of HER-2/neu mRNA and protein, but at a lower level compared with HER-2/neu overexpressing ovarian carcinoma cells. To evaluate the immune response against HER-2/neu expressing HLA-A2-positive (HLA-A2(+)) RCC cells, allogeneic HLA-A2-restricted cytotoxic T-lymphocyte (CTL) lines generated by pulsing dendritic cells with 3 different HER-2/neu-derived peptides, (HER-2(9.369), HER-2(9.435) and HER-2(9.689), were utilized in chromium-release assays. Specific lysis of HER-2/neu expressing HLA-A2(+) RCC cell lines was mediated by CTL lines specific for each of these 3 HER-2/neu-derived epitopes. The fine specificity of 2 CTL clones was defined to the epitopes HER-2(9.435) and HER-2(9.689). Their specificity was then confirmed by cold target inhibition assays. In addition, CTL-mediated lysis was enhanced by pulsing tumor cells with exogenous HER-2/neu-specific peptides. Our data suggest that (i) HER-2/neu is heterogeneously expressed in different subtypes of RCC, (ii) HER-2/neu is naturally processed by RCC and (iii) HER-2/neu epitopes presented by RCC can be recognized by HLA-A2-restricted, HER-2/neu-specific CTL.

Interleukin-7 or interleukin-15 enhances survival of Mycobacterium tuberculosis-infected mice

Both antigen-presenting cells and immune effector cells are required to effectively eradicate or contain Mycobacterium tuberculosis-infected cells. A variety of cytokines are involved to ensure productive "cross talk" between macrophages and T lymphocytes. For instance, infection of macrophages with mycobacteria leads to effective interleukin-7 (IL-7) and IL-15 secretion, and both cytokines are able to maintain strong cellular immune responses of alpha/beta and gamma/delta T cells. Here we show that either cytokine is able to enhance survival of M. tuberculosis-infected BALB/c mice significantly compared to application of IL-2, IL-4, or phosphate-buffered saline (as a control). Enhanced survival could be achieved only when IL-7 or IL-15 was delivered as a treatment (i.e., 3 weeks postinfection), not when it was administered at the time of infection. Increased survival of M. tuberculosis-infected animals was observed following passive transfer of spleen cells harvested from M. tuberculosis-infected, IL-7- or IL-15-treated animals, but not after transfer of spleen cells obtained from mice which received either cytokine alone. Histological examination revealed that IL-7 and IL-15 failed to significantly impact on the number and composition of granulomas formed or the bacterial load. Our data indicated that administration of IL-7 or IL-15 to M. tuberculosis-treated animals resulted in a qualitatively different cellular immune response in spleen cells as reflected by increased tumor necrosis factor alpha and decreased gamma interferon secretion in response to M. tuberculosis-infected antigen-presenting cells.

VHL alterations in human clear cell renal cell carcinoma: association with advanced tumor stage and a novel hot spot mutation

To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed 227 sporadic renal epithelial tumors for mutations and hypermethylations in the von Hippel-Lindau tumor suppressor gene VHL. Tumors were classified according to the recommendations of the Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Somatic VHL mutations were identified by PCR, single-strand conformation polymorphism analysis, and sequencing, and hypermethylations were identified by restriction enzyme digestion and Southern blotting. Frequencies of VHL alterations were established, and an association with tumor type or tumor type and tumor stage was evaluated. VHL mutations and hypermethylations were identified in 45% of clear cell renal cell carcinomas (CCRCCs) and occasionally (3 of 28) in papillary (chromophilic) renal cell carcinomas (RCCs). Lack of VHL mutations and hypermethylations in chromophobe RCCs and oncocytomas was statistically significant (P = 0.0001 and P = 0.0004, respectively). RCCs carrying VHL alterations showed, in nine cases (12%), mutations at a hot spot involving a thymine repeat (ATT.TTT) in exon 2. Tumor staging was critical to the VHL mutation/hypermethylation detection rate in CCRCCs shown by separate evaluation of patients from medical centers in Munich, Heidelberg, and Mainz. The spectrum of pT1, pT2, and pT3 CCRCCs and the VHL mutation/hypermethylation detection rate varied among these three groups. Altogether, VHL alterations were significantly associated with pT3 CCRCCs (P = 0.009). This is the first evidence of frequent somatic VHL mutations at a particular site within exon 2 and an association of VHL mutations/hypermethylations with a standard prognostic factor.

Molecular evidence for derivation of metastatic cells from minor subclones of primary clear renal cell carcinomas

The production of metastases depends on changes in a large number of genes. It is also connected with the interaction of tumor cells with the environment. It has been reported that primary tumor clone domination is also an important factor in metastasizing, and in many neoplasms dominating clones are the metastatic forerunners. Up to now it is unknown whether domination of a given clone in a primary renal cell carcinoma is a crucial factor in forming metastases or rather presence or absence of specific genes imposes the major advantage in the metastatic process. To study the presence or absence of the duplication and mitotic nondisjunction event as one of the phenomenon in the creation of metastases, as well as possible derivation of metastatic cells from the minor subclone of primary tumor, we examined three metastatic renal clear-cell carcinomas in which by comparative genomic hybridization we detected the loss of 3p in the primary tumor and two copies of 3p in the corresponding metastasis. Loss of heterozygosity analyses using markers for 3p25 (D3S1038), 3p21.1 (D3S1295), and 3p14.2 (D3S1481) proved heterozygosity of at least two 3p loci in all metastatic tumors, which indicates the absence of mitotic nondisjunction event as a cause of occurrence of two copies of 3p in metastases. Our results suggest that in some of the clear-cell renal carcinomas metastatic cells may derive from minor subclones of primary tumors.

[Epithelial tumors of the kidney. Pathological subtyping and cytogenetic correlation]

The recent new morphological classification of epithelial renal tumors has overcome the former unspecified adenoma and carcinoma classification by introducing a specific subtyping. Today we divide in oncocytic and metanephrogenic renal cell adenomas, clear cell-, papillary-, chromophobe-, and collecting duct associated renal cell carcinomas, and transitional cell- and neuroendocrine renal carcinomas. These entities are characterized by a definite immunohistological marker spectrum and differing histogenetic pathways. New cytogenetic data have proven specific chromosomal aberrations for the different tumor types and have confirmed the morphological classification. Certain genetic changes are correlated to specific pathological phenotypes especially in oncocytic tumors. It is possible now to propose an in part hypothetical kidney tumor model which describes the development and progression of adenomas and carcinomas of the kidney in an adenoma-carcinoma sequence.

The histology and immunohistochemistry of free buccal mucosa and full-skin grafts after exposure to urine

OBJECTIVE

To investigate the histological and immunohistochemical behaviour of free buccal mucosa and full-skin grafts after exposure to urine.

MATERIALS AND METHODS

A buccal mucosal graft and a full-skin graft were freely transferred into the bladder of 12 minipigs, after stripping the bladder mucosa. Endoscopic investigations were carried out 2 and 5 months after surgery, and the grafts examined after death at 7 months, both histologically and immunohistochemically.

RESULTS

Shrinkage of the full-skin graft was apparent endoscopically in five cases. Of the nine full-skin grafts, four showed severe inflammatory reactions, two necrosis and two ulcerations. Conversely, the 10 buccal mucosal grafts had fewer pathological findings (three minimal inflammation and three with scars) and a pronounced similarity on immunohistochemistry.

CONCLUSION

The buccal mucosal graft showed significantly fewer adverse histopathological findings after long-term exposure to urine than the full-skin graft and is therefore a preferable material for urethral reconstruction.

Expression of the MRP2 gene-encoded conjugate export pump in human kidney proximal tubules and in renal cell carcinoma

Human kidney proximal tubule epithelia express the ATP-dependent export pump for anionic conjugates encoded by the MRP2 (cMRP/cMOAT) gene (symbol ABCC2). MRP2, the apical isoform of the multidrug resistance protein, is an integral membrane glycoprotein with a molecular mass of approximately 190 kD that was originally cloned from liver and localized to the canalicular (apical) membrane domain of hepatocytes. In this study, MRP2 was detected in human kidney cortex by reverse transcription-PCR followed by sequencing of a 826-bp cDNA fragment and by immunoblotting using two different antibodies. Human MRP2 was localized to the apical brush-border membrane domain of proximal tubules by double and triple immunofluorescence microscopy including laser scanning microscopy. The expression of MRP2 in renal cell carcinoma was studied by reverse transcription-PCR and immunoblotting in samples from patients undergoing tumor-nephrectomy without prior chemotherapy. Clear-cell carcinomas, originating from the proximal tubule epithelium, expressed MRP2 in 95% (18 of 19) of cases. Immunofluorescence microscopy of MRP2 in clear-cell carcinoma showed a lack of a distinct apical-to-basolateral tumor cell polarity and an additional localization of MRP2 on intracellular membranes. MRP2, the first cloned ATP-dependent export pump for anionic conjugates detected in human kidney, may be involved in renal excretion of various anionic endogenous substances, xenobiotics, and cytotoxic drugs. This conjugate-transporting ATPase encoded by the MRP2 gene has a similar substrate specificity as the multidrug resistance protein MRP1, and may contribute to the multidrug resistance of renal clear-cell carcinomas.

Inverse regulation of vascular endothelial growth factor and VHL tumor suppressor gene in sporadic renal cell carcinomas is correlated with vascular growth: an in vivo study on 29 tumors

Tumors associated with the VHL (von Hippel-Lindau) disease, such as hemangioblastomas and renal carcinomas and their sporadic counterparts, are cystic and well vascularized. Mutations of the VHL tumor-suppressor gene and elevated levels of vascular endothelial growth factor (VEGF) have been described in these tumors. The upregulation of VEGF has been shown in vitro as a consequence of alteration of the VHL gene. No comprehensive in vivo analysis has yet been carried out of the factors affecting tumor growth, vascularization, VEGF, and VHL expression. We performed immunohistochemistry and mRNA studies on primary sporadic renal carcinomas and matching normal renal tissue. We semiquantitatively analyzed 29 renal carcinomas (22 clear cell, 5 chromophilic, 2 chromophobic tumors) for VHL mRNA, and VEGF expression for morphology and tumor size. Immunohistochemistry was carried out for VEGF protein expression, vascularization, and macrophage infiltration. Vascularization of the chromophilic renal carcinomas was lower than that of the clear cell type of renal carcinoma. Low VEGF protein expression was seen in four of the five chromophilic renal carcinomas. We found two groups of clear cell renal cell carcinoma: one with reduced VHL mRNA and increased VEGF mRNA, and the other without significantly altered VHL or VEGF mRNAs. Tumor vascularization was correlated with VEGF protein and seemed to be independent of macrophage infiltration. Our in vivo findings support the inverse relationship between the regulation of VHL and that of VEGF. Our data also indicate that there may be an VHL-independent pathway for the induction of tumor vascularization.