Baseline neutrophil-to-lymphocyte ratio as a predictive and prognostic biomarker in patients with metastatic castration-resistant prostate cancer treated with cabazitaxel versus abiraterone or enzalutamide in the CARD study

Background

There is growing evidence that a high neutrophil-to-lymphocyte ratio (NLR) is associated with poor overall survival (OS) for patients with metastatic castration-resistant prostate cancer (mCRPC). In the CARD study (NCT02485691), cabazitaxel significantly improved radiographic progression-free survival (rPFS) and OS versus abiraterone or enzalutamide in patients with mCRPC previously treated with docetaxel and the alternative androgen-receptor-targeted agent (ARTA). Here, we investigated NLR as a biomarker.

Patients and methods

CARD was a multicenter, open-label study that randomized patients with mCRPC to receive cabazitaxel (25 mg/m² every 3 weeks) versus abiraterone (1000 mg/day) or enzalutamide (160 mg/day). The relationships between baseline NLR [< versus ≥ median (3.38)] and rPFS, OS, time to prostate-specific antigen progression, and prostate-specific antigen response to cabazitaxel versus ARTA were evaluated using Kaplan–Meier estimates. Multivariable Cox regression with stepwise selection of covariates was used to investigate the prognostic association between baseline NLR and OS.

Results

The rPFS benefit with cabazitaxel versus ARTA was particularly marked in patients with high NLR {8.5 versus 2.8 months, respectively; hazard ratio (HR) 0.43 [95% confidence interval (CI) 0.27-0.67]; P < 0.0001}, compared with low NLR [7.5 versus 5.1 months, respectively; HR 0.69 (95% CI 0.45-1.06); P = 0.0860]. Higher NLR (continuous covariate, per 1 unit increase) independently associated with poor OS [HR 1.05 (95% CI 1.02-1.08); P = 0.0003]. For cabazitaxel, there was no OS difference between patients with high versus low NLR (15.3 versus 12.9 months, respectively; P = 0.7465). Patients receiving an ARTA with high NLR, however, had a worse OS versus those with low NLR (9.5 versus 13.3 months, respectively; P = 0.0608).

Conclusions

High baseline NLR predicts poor outcomes with an ARTA in patients with mCRPC previously treated with docetaxel and the alternative ARTA. Conversely, the activity of cabazitaxel is retained irrespective of NLR.

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Baseline NLR was evaluated as a biomarker in patients with mCRPC treated with cabazitaxel versus abiraterone or enzalutamide.

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High baseline NLR predicted poor outcomes with abiraterone or enzalutamide in patients with mCRPC.

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Clinical benefit from cabazitaxel was retained in higher baseline NLR patients.

[Changes in the treatment of metastatic prostate cancer-new data and open questions]

The availability of taxane-based chemotherapy and androgen-receptor-targeted agents (ARTAs) have significantly broadened the therapeutic options for patients with metastatic prostate cancer and may also result in longer patient survival. The therapeutic sequence of ARTAs and taxanes may influence outcome and therefore decisions should be made on an individual basis. This article provides guidance for therapeutic decision-making in daily clinical practice by working out criteria that can be used to support individual therapeutic decisions. The focus is on metastatic castration-naive prostate cancer, oligometastatic disease as well as non-metastatic and metastatic castration-resistant prostate cancer.

[Treatment situation in metastastic Castration Naive Prostate Cancer (mCRPC) and the implications on clinical routine]

There is an ongoing change of paradigm in the treatment of metastatic prostate cancer (mPC). Taxan-based chemotherapy demonstrated a prolonged survival of patients in several randomized phase III trials. This is true in the situation of metastatic castration-resistent prostate cancer (mCRPC) as well as in the hormone-naïve stage (metastatic castration-naive PC [mCNPC]). In patients with mCNPC, treatment with docetaxel in combination with androgen deprivation therapy (ADT) prolonged the median total survival time by 15 months in comparison to ADT alone. Comparable results were obtained by the endocrine combination treatment with ADT/abiraterone. With the current data in mind it seems to be useful to discuss the value of early combination therapy with ADT/docetaxel or ADT/abiraterone as well as the impact on further treatment options in the mCRPC setting and to define criteria for treatment decisions in clinical practice.

[Decision aids for patients are widely accepted by German urologists : A survey among members of the German Society of Urology (DGU) and the Federation of German Urologists (BDU)]

BACKGROUND

Treatment decision making remains a complex task for localized prostate cancer. Decision aids for patients can support the medical consultation. However, it is not known if German urologists accept decision aids for patients. Comparative data exist from a current survey among american urologists and radio oncologists.

MATERIALS AND METHODS

From October through November 2014 we conducted an online survey consisting of 11 multiple-choice questions and an optional free text commentary among the members of DGU and BDU. All data was processed anonymously. We received 464 complete responses for a 6.6 % return rate. For group comparison we applied the Chi2-test.

RESULTS

Respondents' median age was 50 (range 26-87) years and 15 % were female. 7 % were residents, 31 % employed at a clinic, and 57 % in private practice. Due to the low response rate of younger colleagues the results were not representative for the basic population. Regardless of age (p = 0.2) and professional environment (p = 1) shared decision making was preferred by 89 %. When counseling their patients with localized prostate cancer 20 % relied exclusively on conversation. To support their conversation 63 % used print media, 49 % decision aids, 33 % contact offers to support groups, 24 % Internet resources and 13 % video material. From using decision aids 86 % expected positive effects for patients and 78 % for physicians (p = 0.017). 15 % expected a change of the treatment decision. 77 % would motivate their patients to use a decision aid.

CONCLUSIONS

In comparison to the opinion of american urologists and radio oncologists the acceptance of decision aids for patients among German urologists is significantly higher.

[Open and minimally invasive partial nephrectomy. Management of complications]

Current guidelines increasingly recommend organ-preserving surgical procedures in the treatment of renal tumors. Both the open surgical and minimally invasive surgical techniques are well established. In the literature, various systems for the systematic evaluation of comorbidities and complications have been reported. Already while taking the patient's history and preoperative planning prior to partial nephrectomy, it is recommended that a detailed risk assessment be carried out regarding expected complications. Essentially the two critical factors - the comorbidities of the patient and anatomic complexity level of the tumor - should be evaluated in order to achieve the best possible selection of patients for a partial nephrectomy and the determination of the surgical method.

[Practical information on the use of port systems]

As a result of the dynamic developments in oncology over the last few years, multimodal therapeutic options are now available for the treatment of cancer patients in practically all diseases stages. This has led to an increase in the use of all forms of chemotherapy. Low and moderately complex chemotherapy options are being increasingly employed in outpatient and day clinic settings. For this reason, among others, the implantation of central venous port systems has progressed to become an important component in the therapeutic planning for oncological patients.

[Patients with bladder cancer in clinical stage T2 : survival benefit of downstaging in comparison to patients with confirmed muscle invasion in cystectomy specimens]

BACKGROUND

Few and partially contradictory data are available regarding the prognostic signature of downstaging of muscle-invasive clinical tumour stages in patients treated with radical cystectomy.

MATERIALS AND METHODS

Clinicopathological parameters of 1,643 patients (study group, SG) treated with radical cystectomy due to muscle-invasive urothelial bladder cancer were summarized in a multi-institutional database. Patients of the SG fulfilled the following conditions: clinical tumour stage T2 N0 M0 and no administration of neoadjuvant radiation or chemotherapy. Cancer-specific survival (CSS) rates were calculated referring to pathological tumour stages in cystectomy specimens (<pT2, pT2, >pT2) (mean follow-up: 51 months). Furthermore, a multivariable model integrating clinical information was developed in order to predict the probability of downstaging.

RESULTS

A total of 173 patients (10.5%) of the SG presented with downstaging in pathological tumour stages (pT0: 4.8%, pTa: 0.4%, pTis: 1.3%, pT1: 4.1%); 12 of these patients had positive lymph nodes (7%, in comparison with 21% pN+ of pT2 tumours and 43% of >pT2 tumours). Patients with tumour stages <pT2, pT2 and >pT2 had CSS rates after 5 years of 89, 69 and 46%, respectively (p<0.001). In a multivariable Cox model the presence of pathological downstaging resulted in a significant reduction of cancer-specific mortality (HR 0.30; 95% CI 0.18-0.50). By logistic regression analysis the date of TURB (benefit for more recent operations) was identified as the only independent predictor for downstaging of muscle-invasive clinical tumour stages. Age, gender, grading and associated Tis in the TURB did not reveal any significant influence.

CONCLUSION

Patients with muscle-invasive clinical tumour stages and downstaging in cystectomy specimens represent a subgroup with significantly enhanced CSS rates. Further trials that integrate the parameters tumour size, stages cT2a vs cT2b and focality are required in order to define the independent prognostic signature of downstaging of tumour stages more precisely.

Update on systemic therapies of metastatic renal cell carcinoma

PURPOSE

Recent advances in understanding the molecular biology of advanced and metastatic renal cell carcinoma (RCC) have led to the development of several targeted agents that show impressive antitumor efficacy. The integration of these drugs into clinical practice has revolutionized the therapeutic management of RCC.

METHODS

We reviewed data on all approved targeted agents in the first-line and second-line setting, as well as, studies involving sequential therapy. Data from phase III trials are discussed, and an optional therapeutic algorithm is presented.

RESULTS

Sunitinib should be used as the first-line treatment of choice for good- and intermediate-risk patients according to Memorial Sloan-Kettering Cancer Center (MSKCC) criteria, whereas temsirolimus is recommended for the poor-risk group. The combination of bevacizumab and INF-alpha can be regarded as an alternative to sunitinib. After cytokine failure, patients should be recommended to sorafenib. Everolimus must be considered after first-line failure of a tyrosine kinase inhibitor (TKI); furthermore, recent evidence suggests sequential use of TKIs before administration of everolimus.

CONCLUSIONS

A range of potent drugs are available to patients with metastatic RCC. Treatment decisions should be made carefully taking into consideration that all targeted agents only have a palliative effect with prolongation of life, but do not cure metastatic RCC.

Lymphangiogenesis in kidney cancer: expression of VEGF-C, VEGF-D and VEGFR-3 in clear cell and papillary renal cell carcinoma

The vascular endothelial growth factors VEGF-C, VEGF-D and its receptor, VEGFR-3, are overexpressed in different malignancies and associated with lymph node metastasis and poor prognosis. We analysed these factors in clear cell (ccRCC) and papillary (pRCC) renal cell carcinoma (RCC). The results were correlated with various clinicopathological parameters (CPP). We constructed a tissue microarray with tumor samples of 135 (81%) ccRCC and 31 (19%) pRCC. After immunohistochemical staining using polyclonal antibodies for VEGF-C, VEGF-D and VEGFR-3, a semiquantitative analysis was performed to determine the levels of expression. The results were compared between the two subgroups and were correlated with CPP. In the two subgroups the expression of VEGF-C was significantly correlated with that of VEGF-D (p<0.001). There was an increased expression of VEGF-C in 11% of ccRCC and 36% of pRCC (p=0.002). VEGF-D expression was positive by means of analysis in 22% of ccRCC and 42% of pRCC (p=0.039). There was no significant difference regarding the expression of VEGFR-3 between the subgroups (44% ccRCC and 61% pRCC, p=0.11). No correlation was found between the expression of the analysed parameters and CPP (TNM, grading, progression-free survival and overall survival) in either the entire group or in the two subgroups. In summary, ccRCC and pRCC show a different expression pattern of the analysed lymphangiogenic factors. Further studies are necessary to confirm these results and to determine whether the VEGF-C/VEGF-D/VEGFR-3-axis can play a role as a prognostic tool or a target for therapeutic intervention in renal cell carcinoma.

Serum antibodies against prostasomal clusterin in prostate cancer patients

OBJECTIVE

Clusterin is a ubiquitous secretory sulphated glycoprotein present in prostasomes. It is an anti-apoptotic mediator in prostate cancer and is among the most frequently occurring prostasomal proteins immunogenic in prostate cancer patients. The aim of the present study was to investigate the occurrence of anti-clusterin antibodies in the serum of patients with prostate cancer and whether there is a relationship between anti-clusterin antibody titres and other clinico-pathological variables.

MATERIAL AND METHODS

Serum samples were collected from 391 consecutive patients with suspected prostate cancer (150 benign prostate and 241 prostate cancer). The patients' serum samples were used in an ELISA where microtitre wells were coated with purified clusterin from serum of a healthy volunteer. Flow cytometric studies of clusterin and prostasomes were performed.

RESULTS

Flow cytometric analyses revealed the presence of clusterin on the surface of seminal prostasomes. Anti-clusterin ELISA titres in sera of patients did not differ significantly from those of a control group. A significant "inverse" correlation existed between anti-clusterin ELISA titres and lymph node metastases (p = 0.047), but only 11 out of 161 patients had metastases. These titres correlated significantly with total prostate (p = 0.021) and transitional zone (p = 0.015) volumes of the patients.

CONCLUSIONS

The correlation between serum anti-clusterin antibody titres and other clinico-pathological variables was generally weak in prostate cancer patients, although clusterin has been assigned an important role in tumourigenesis and progression of prostate cancer. However, the anti-clusterin antibody titre appeared to be related to prostate volume, correlating to both transitional zone volume and total volume of the prostate.

[Retroperitoneoscopic excision of an adrenal cyst]

INTRODUCTION

Laparoscopic management of adrenal benign cysts is the method of choice today. In contrast to the transabdominal laparoscopic approach, retroperitoneoscopy is rarely performed, although it seems to be a comparable method and alternative technique for cyst resection.

CASE REPORT

A thin 27-year-old woman in good condition presented with epigastric and left flank pain as well as reflux of gastric acid. A large adrenal cystic lesion was detected on ultrasonography and computed tomography of the abdomen. The question of whether the cyst arose from the upper pole of the left kidney or from the adrenal gland could not be answered. Retroperitoneoscopic excision of the cystic lesion was performed. The histopathological work-up revealed the finding of an adrenal pseudocyst. Symptoms of epigastric and left flank pain as well as reflux of gastric acid resolved after pseudocyst removal.

CONCLUSIONS

The retroperitoneoscopic approach for symptomatic adrenal cyst resection represents an effective, cost-reducing and durable treatment.

[New markers for pharmacological targeting in bladder cancer with lymph node metastasis]

PURPOSE

VECF-C, -D and their receptor Flt-4 are associated with lymph node metastasis and a poor prognosis in many tumour entities. We have analysed the expression of these factors in transitional cell carcinoma of the bladder with positive lymph nodes.

MATERIALS AND METHODS

We constructed "tissue microarrays" (TMAs) from bladder cancer specimens (BC-array) and corresponding lymph node metastases (LN-array) of 73 patients, who all underwent radical cystectomy and bilateral lymphadenectomy. After immunohistochemical staining, semiquantitative analysis was performed using polyclonal antibodies for VEGF-C, -D and Flt-4. The results were correlated with various histopathological and clinical variables.

RESULTS

VEGF-C (p = 0.007) and Flt-4 (p = 0.019) were significantly higher expressed in the LN-array compared to the BC-array. In the LN-array VEGF-D correlated with T-(p = 0.013) and N-stage (p = 0.030) Flt-4 correlated with N-stage (p = 0.011) and distant metastasis (p = 0.011) in the BC-array, as well as with T-(p = 0.004) and N-stage (p = 0.014) in the LN-array. Accordingly, in the LN-array VEGF-D positive patients showed both a shorter disease-free survival (p = 0.028) and a poorer overall survival (p = 0.014). Similarly, Flt-4 positive patients had a shorter overall survival (p = 0.033).

CONCLUSIONS

Patients with transitional bladder cancer and lymph node metastasis have a poorer prognosis when they overexpress VEGF-D and Flt-4 in their lymph nodes. Pharmacological targeting of these factors could improve their overall survival.

Treatment of metastatic papillary renal cell carcinoma with immunochemotherapy with interleukin-2, interferon-alpha and 5- fluorouracil

15644

Background: Combined immunochemotherapy with interleukin-2 (IL-2), interferon-alpha (IFN-a) and 5-fluorouracil (5-FU) is an established first-line therapy for metastatic renal cell carcinoma (RCC). However, data on histologic parameters predictive of clinical benefit are rare. Methods: Treatment courses of 164 patients consisted of IFN-a at 9 x 106 IU on day 1 of weeks 1 and 4 and days 1, 3, 5 of weeks 2 and 3; and at 18 x 106 IU on days 1, 3, 5 of weeks 5–8. Interleukin-2 was administrated at 18 x 106 IU twice daily on days 3–5 of weeks 1 and 4; and at 9 x 106 IU on days 1, 3, 5 of weeks 2 and 3. Additionally, patients received 5-FU at 750 mg m-2 on day 1 of weeks 5–8. In 153 patients, radical nephrectomy had revealed 22 cases of papillary RCC (pRCC, 13.4%) and 131 cases of clear cell RCC (ccRCC, 79.9%). In the remaining 11 (6.7%) their disease was inoperable. The overall response rates were evaluated according to WHO criteria. Results: For ccRCC and inoperable disease, responses of 34.4% and 27.3% after one cycle and 28.8% and 16.7% after two cycles, respectively, were noted. In contrast, no patient with pRCC showed any response after two cycles of combined immunochemotherapy. Conclusions: No objective response was seen in patients with pRCC. Hence, immunotherapeutic agents must be questioned in this histologic subtype.

No significant financial relationships to disclose.

Expression of the endothelin axis and microvessel density in bladder cancer

4583

Background: Endothelin-1 (ET-1) and its receptors ETAR and ETBR, referred to as the Endothelin (ET)-axis play an emerging role in cancer. The ET-axis has been shown to be involved in proliferation, angiogenesis and metastasis. We investigated the effect of the ET-axis on microvessel density (MVD) and on the clinical prognosis in patients with invasive carcinoma of the bladder. Methods: Archival tumor tissue of 157 consecutive patients was reviewed and representing tumor blocks were selected. Paraffin sections were assessed immunhistochemically using mono- and polyclonal antibodies for ET-1, ETAR,ETBR and CD34 (MVD). Staining intensities were analyzed semiquantitatively and the MVD was calculated as vessels per field. The results were correlated with various pathological and clinical factors, as well as with disease-free and overall survival. Results: Overexpression of ET-1, ETAR and ETBR was identified in 26.8%, 58.8% and 76.9% of cases, respectively. Normal urothelium was constantly negative. No association with TNM staging and histologic grading was found. However, patients with ETBR expression tended to have organ-confined tumors (P = 0.16) and no vascular invasion (P = 0.09), the latter being statistically significant in the subgroup of G3 tumors (P = 0.02). T1 and T2 (MVD = 32,2) tumors had greater MVD compared to T3 and T4 tumors (MVD = 21,2) (P = 0.02), showing an association of MVD and overexpression of ET-1 (P = 0.027). ETBR-positive tumors were associated with favorable disease-free survival (P = 0.04). In urothelial carcinomas the MVD was 23,7, whereas squamous cell carcinomas had a MVD of 17,8 (P = 0.04). Conclusion: The ET-axis is overexpressed in invasive bladder cancer. Urothelial carcinomas are significantly greater vascularized compared to squamous cell carcinomas. Organ-confined tumors showed more MVD than T3 and T4 tumors, which is related to ET-1 expression in this subgroup. ETBR appears to predominate in bladder cancer and is associated with a more favorable prognosis.

No significant financial relationships to disclose.

[Bilateral renal angiomyolipomas with a thrombus in the inferior caval vein. Rare growth pattern of a benign tumor]

Renal angiomyolipomas are mesenchymal tumors that are composed of fat tissue, smooth muscle cells and vessels. These are benign tumors, but in rare cases they show a more aggressive growth pattern with invasion into the venous system but without revealing any signs of malignancy. We report a new case of bilateral renal angiomyolipomas with a caval thrombus in a 36 year old female patient with tuberous sclerosis, and give a brief review of the related literature.

[Expression of Her2/neu in locally advanced bladder cancer: implication for a molecular targeted therapy]

PURPOSE

The Her2/neu oncoprotein, belonging to the erbB-receptor family, is known to contribute to physiological mechanisms of cell proliferation by intrinsic tyrosine-kinase-activity. Overexpression has been shown for several tumors and is known to influence malignant cell proliferation, metastasis and angiogenesis. The clinical use of Her2-targeting agents has emerged in clinical research. In our study, we analyzed Her2/neu expression in urothelial tumors.

MATERIALS AND METHODS

Her2/neu expression was evaluated immunohistochemically (IHC) in 127 patients undergoing radical cystectomy (DAKO- Herceptest). Additionally, fluorescent-in-situ-hybridisation (FISH) was carried out in all immunohistochemically "2+" cases (n = 41) to assess gene amplification. After grading the Her2/neu-overall status, Her2/neu expression was correlated with clinicopathological parameters and survival data.

RESULTS

An immunohistochemical Her2/neu expression was found in 95 of 127 cases (74.8 %). Of all 41 cases with "2+" staining (32.2 %), 11 cases (26.8 %) showed positive amplification by FISH. Therefore, including the IHC 3+ cases, a Her2/neu overall status of 22 positive (17.3 %) tumors was assessed. Correlation with clinical data showed a relation to lymph node metastasis (P = 0.06), lymph vessel invasion (P = 0.07) and metastasis (P = 0.002). No further associations with other parameters nor with overall survival (P = 0.73) or disease-free survival (P = 0.63) were found.

CONCLUSIONS

Her2/neu upregulation is found in invasive bladder cancer with significant differences in protein expression and gene amplification. The association with lymphogenic and distant metastases implicates a late event in carcinogenesis. Moreover, there was no further association with clinicopathological parameters and survival. The possible role of a molecular targeted therapy of advanced bladder cancer with Her2/neu targeting agents should be assessed in further clinical trials.

[Therapy of hormone refractory prostate cancer: new standards, new trends]

Hormone-refractory prostate cancer is diagnosed with increasing incidence and has become a growing challenge for urologists. The improved understanding of the tumor biological mechanisms of the hormone-refractory state has led to innovative therapeutic developments in the field of hormonal and cytotoxic therapies. Recently, two large randomized Phase III trials with docetaxel-based chemotherapy were able to show prolonged survival and a positive influence on pain and quality of life, establishing a new standard of care for these patients. Moreover, bisphosphonates seem to have positive influence on selected patients. In the growing field of molecular targeted therapy, first trials with compounds, such as tyrosine kinase inhibitors, anti-sense oligonucleotides, angiogenesis inhibitors and endothelin receptor antagonists, show promising results in the treatment of patients with hormone-refractory prostate cancer.

[Obstructive uropathy in adults]

Urinary tract obstruction is a common clinical problem. The obstruction of the urinary flow may be acute or chronic, partial or complete, unilateral or bilateral, and may occur at any site of the urinary tract. The major causes of urinary tract obstruction vary with the age of the patient. Anatomic abnormalities, e. g. ureteropelvic junction obstruction, account for the majority of cases in children. In comparison, calculi are most common in young adults, while prostatic hyperplasia or carcinoma, retroperitoneal or pelvic neoplasms, and calculi are the primary causes in older patients. Urinary tract obstruction results in different pathophysiological changes causing various symptoms. In addition to the aetiology, pathophysiology and clinical presentation of obstructive uropathy in adults, modern diagnostic and therapeutic options are presented in this review.

Expression of endothelin-A-receptor predicts unfavourable response to neoadjuvant chemotherapy in locally advanced breast cancer

Endothelin-1 (ET-1) and its receptors (ET_AR and ET_BR), referred to as the endothelin (ET) axis, are overexpressed in breast carcinomas and appear to influence tumour growth and progression. The objective of this study was to determine the effect of expression of the ET axis in breast carcinomas on response to cytotoxic chemotherapy. The study included 44 patients with locally advanced breast cancer participating in a prospective phase III study evaluating high-dose neoadjuvant chemotherapy of epirubicin and cyclophosphamide. Expression of ET-1, ET_AR and ET_BR was determined by semiquantitative immunohistochemical analysis of breast cancer tissue from prechemotherapy tru-cut biopsies. Immunohistochemical staining was positive for ET-1 in 61.5%, for ET_AR in 35% and for ET_BR in 35.9% of breast carcinomas. Pathological response to chemotherapy was significantly decreased in ET_AR-positive patients (P=0.002). In total, 50% of ET_AR-positive patients as compared to 7.7% of ET_AR-negative patients attained pathologically ‘no change’. Logistic regression confirmed ET_AR as an independent predictive marker for pathological response (P=0.009). These data indicate that increased expression of ET_AR in breast carcinomas is associated with resistance to chemotherapy. Determination of ET_AR status may serve as a predictive marker for identifying patients less likely to be responsive to conventional chemotherapy.

[Cyclooxygenase-2-expression in bladder cancer: tumor-biological and clinical implications]

PURPOSE

Cyclooxygenase-2 (Cox-2) contributes to the carcinogenesis of human tumors by various mechanisms. As Cox-2-expression has been found in most human neoplasms, selective Cox-2-inhibitors could be used as a molecular targeted therapy, and first clinical trials have already been initiated. Moreover, Cox-2-inhibitors have been shown to add to the activity of conventional cytotoxic therapies in experimental and clinical studies. We analyzed Cox-2-expression in bladder cancer and its implications on clinical parameters.

MATERIALS AND METHODS

Cox-2-expression was evaluated immunohistochemically in 157 patients undergoing radical cystectomy. Sixty-two patients had received cisplatin-based treatment during follow-up, either as adjuvant therapy or for metastatic disease. Cox-2-expression was correlated with clinical and pathological parameters, survival data and outcome of chemotherapy.

RESULTS

Cox-2 was expressed in 83.4 % of tumors. No association was found with TNM-staging and histological grading, but a significant relation to the histologic subtype (transitional vs. squamous cell carcinoma, p = 0.038) was present. Survival analysis showed no impact of Cox-2-expression on overall or disease-free survival. However, a subgroup of chemotherapy patients demonstrated a significant correlation of strong Cox-2-expression with worse overall survival time (p = 0.01).

CONCLUSIONS

Cox-2-expression was found in the majority of invasive bladder tumors. For patients who underwent chemotherapy, a significant relation of Cox-2-expression and worse overall survival was demonstrated. Cox-2 seems to be an interesting molecular target for the diagnosis and therapy of bladder cancer. Further experimental and clinical studies are warranted to elucidate whether Cox-2-inhibition can serve as an additive therapy to chemotherapy of bladder cancer.

Das benigne Fibroepitheliom des Harnleiters

Gross hematuria without pain is a classical symptom of malignancy in the urinary tract. Despite the presence of other symptoms such as a history of heavy smoking or radiologic evidence of tumor growth, it may still be caused by a benign lesion. This is demonstrated by the case of a 38 year old man with a fibroepithelioma of the left ureter. While discussing the differential diagnostic and treatment procedures it is shown that even in the era of modern non-invasive imaging techniques there is still an important place for retrograde ureteropyelography in the evaluation of the upper urinary tract.

The vav exchange factor is an essential regulator in actin-dependent receptor translocation to the lymphocyte-antigen-presenting cell interface

During the interaction of a T cell with an antigen-presenting cell (APC), several receptor ligand pairs, including the T cell receptor (TCR)/major histocompatibility complex (MHC), accumulate at the T cell/APC interface in defined geometrical patterns. This accumulation depends on a movement of the T cell cortical actin cytoskeleton toward the interface. Here we study the involvement of the guanine nucleotide exchange factor vav in this process. We crossed 129 vav(-/-) mice with B10/BR 5C.C7 TCR transgenic mice and used peptide-loaded APCs to stimulate T cells from the offspring. We found that the accumulation of TCR/MHC at the T cell/APC interface and the T cell actin cytoskeleton rearrangement were clearly defective in these vav(+/-) mice. A comparable defect in superantigen-mediated T cell activation of T cells from non-TCR transgenic 129 mice was also observed, although in this case it was more apparent in vav(-/-) mice. These data indicate that vav is an essential regulator of cytoskeletal rearrangements during T cell activation.

Thirty-six views of T-cell recognition

While much is known about the signalling pathways within lymphocytes that are triggered during activation, much less is known about how the various cell surface molecules on T cells initiate these events. To address this, we have focused on the primary interaction that drives T-cell activation, namely the binding of a particular T-cell receptor (TCR) to peptide-MHC ligands, and find a close correlation between biological activity and off-rate; that is, the most stimulatory TCR ligands have the slowest dissociation rates. In general, TCRs from multiple histocompatibility complex (MHC) class-II-restricted T cells have half-lives of 1-11s at 25 degrees C, a much narrower range than found with antibodies and suggesting a strong selection for an optimum dissociation rate. TCR ligands with even faster dissociation rates tend to be antagonists. To observe the effects of these different ligands in their physiological setting, we made gene fusions of various molecules with green fluorescent protein (GFP), transfected them into the relevant lymphocytes, and observed their movements during T-cell recognition using multicolour video microscopy. We find that clustering of CD3zeta-GFP and CD4-GFP on the Tcell occurs concomitantly or slightly before the first rise in calcium by the T cell, and that various GFP-labelled molecules on the B-cell side cluster shortly thereafter (ICAM-1, class II MHC, CD48), apparently driven byT-cell molecules. Most of this movement towards the interface is mediated by signals through the co-stimulatory receptors, CD28 and LFA-1, and involves myosin motors and the cortical actin cytoskeleton. Thus, we have proposed that the principal mechanism by which co-stimulation enhances T-cell responsiveness is by increasing the local density of T-cell activation molecules, their ligands and their attendant signalling apparatus. In collaboration with Michael Dustin and colleagues, we have also found that the formation and stability of the TCR-peptide-MHC cluster at the centre of the interaction cap between T and B cells is highly dependent on the dissociation rate of the TCR and its ligand. Thus, we are able to link this kinetic parameter to the formation of a cell surface structure that is linked to and probably causal with respect to T-cell activation.

Differential clustering of CD4 and CD3zeta during T cell recognition

Whereas T helper cells recognize peptide-major histocompatibility complex (MHC) class II complexes through their T cell receptors (TCRs), CD4 binds to an antigen-independent region of the MHC. Using green fluorescent protein-tagged chimeras and three-dimensional video microscopy, we show that CD4 and TCR-associated CD3zeta cluster in the interface coincident with increases in intracellular calcium. Signaling-, costimulation-, and cytoskeleton-dependent processes then stabilize CD3zeta in a single cluster at the center of the interface, while CD4 moves to the periphery. Thus, the CD4 coreceptor may serve primarily to "boost" recognition of ligand by the TCR and may not be required once activation has been initiated.

Visualizing lymphocyte recognition

Studies of T cell recognition have entered new territory now that some of the basic issues of genetics, biochemistry and structure have been addressed, at least in outline form. In the present work, the focus is on a new aspect of T cell recognition that goes beyond classical biochemistry to ask, how to TCR and other cell surface molecules cooperate to initiate and control recognition?'

A receptor/cytoskeletal movement triggered by costimulation during T cell activation

During T cell activation, the engagement of costimulatory molecules is often crucial to the development of an effective immune response, but the mechanism by which this is achieved is not known. Here, it is shown that beads attached to the surface of a T cell translocate toward the interface shortly after the start of T cell activation. This movement appears to depend on myosin motor proteins and requires the engagement of the major costimulatory receptor pairs, B7-CD28 and ICAM-1-LFA-1. This suggests that the engagement of costimulatory receptors triggers an active accumulation of molecules at the interface of the T cell and the antigen-presenting cell, which then increases the overall amplitude and duration of T cell signaling.

Initiation of signal transduction through the T cell receptor requires the multivalent engagement of peptide/MHC ligands [corrected]

While much is known about intracellular signaling events in T cells when T cell receptors (TCRs) are engaged, the mechanism by which signaling is initiated is unclear. We have constructed defined oligomers of soluble antigen-major histocompatibility complex (MHC) molecules, the natural ligands for the TCR. Using these to stimulate specific T cells in vitro, we find that agonist peptide/MHC ligands are nonstimulatory as monomers and minimally stimulatory as dimers. Similarly, a partial-agonist ligand is very weakly active as a tetramer. In contrast, trimeric or tetrameric agonist ligands that engage multiple TCRs for a sustained duration are potent stimuli. Ligand-driven formation of TCR clusters seems required for effective activation and helps to explain the specificity and sensitivity of T cells.

Visualizing the dynamics of T cell activation: intracellular adhesion molecule 1 migrates rapidly to the T cell/B cell interface and acts to sustain calcium levels

T cell recognition typically involves both the engagement of a specific T cell receptor with a peptide/major histocompatibility complex (MHC) and a number of accessory interactions. One of the most important interactions is between the integrin lymphocyte function-associated antigen 1 (LFA-1) on the T cell and intracellular adhesion molecule 1 (ICAM-1) on an antigen-presenting cell. By using fluorescence video microscopy and an ICAM-1 fused to a green fluorescent protein, we find that the elevation of intracellular calcium in the T cell that is characteristic of activation is followed almost immediately by the rapid accumulation of ICAM-1 on a B cell at a tight interface between the two cells. This increased density of ICAM-1 correlates with the sustained elevation of intracellular calcium in the T cell, known to be critical for activation. The use of peptide/MHC complexes and ICAM-1 on a supported lipid bilayer to stimulate T cells also indicates a major role for ICAM-1/LFA-1 in T cell activation but, surprisingly, not for adhesion, as even in the absence of ICAM-1 the morphological changes and adhesive characteristics of an activated T cell are seen in this system. We suggest that T cell antigen receptor-mediated recognition of a very small number of MHC/peptide complexes could trigger LFA-1/ICAM-1 clustering and avidity regulation, thus amplifying and stabilizing the production of second messengers.

Kinetics and extent of T cell activation as measured with the calcium signal

We have characterized the calcium response of a peptide-major histocompatibility complex (MHC)-specific CD4(+) T lymphocyte line at the single cell level using a variety of ligands, alone and in combination. We are able to distinguish four general patterns of intracellular calcium elevation, with only the most robust correlating with T cell proliferation. Whereas all three antagonist peptides tested reduce the calcium response to an agonist ligand, two give very different calcium release patterns and the third gives none at all, arguing that (a) antagonism does not require calcium release and (b) it involves interactions that are more T cell receptor proximal. We have also measured the time between the first T cell-antigen-presenting cell contact and the onset of the calcium signal. The duration of this delay correlates with the strength of the stimulus, with stronger stimuli giving a more rapid response. The dose dependence of this delay suggests that the rate-limiting step in triggering the calcium response is not the clustering of peptide-MHC complexes on the cell surface but more likely involves the accumulation of some intracellular molecule or complex with a half-life of a few minutes.

Efficient production of heat-labile enterotoxin mutant proteins by overexpression of dsbA in a degP-deficient Escherichia coli strain

Escherichia coli heat-labile enterotoxin (LT) mutants containing Val60-->Gly or Ser114-->Lys substitutions in the A subunit do not produce the A subunit efficiently in E. coli. These mutants accumulate mostly the B pentamer devoid of the A subunit in the periplasmic space. Here we show that overproduction of the periplasmic chaperone DsbA, which is involved in disulfide bond formation, in a strain deficient in the periplasmic protease DegP allows efficient production of the mutant LT molecules. Our results suggest that the formation of the oligomeric toxin is influenced by DsbA, which helps protein folding, and by DegP, which removes the folded intermediates that can be untoxic for the cell.

Electrical manipulation of glycan-phosphatidyl inositol-tethered proteins in planar supported bilayers

Electric fields have been used to manipulate and concentrate glycan-phosphatidyl inositol (GPI)-tethered proteins in planar supported bilayers. Naturally GPI-linked CD48, along with engineered forms of I-Ek and B7-2, in which their transmembrane domains have been genetically replaced with the GPI linkage, were studied. The proteins were labeled with fluorescently tagged antibodies, allowing the electric field-induced behavior to be followed by epifluorescence microscopy. All three protein complexes were observed to migrate toward the cathode with the B7-2 and CD48, each tethered to the membrane by a single GPI linker, moving significantly faster than the I-Ek, which has two GPI linkers. Patterns scratched into the membrane function as barriers to lateral diffusion and were used to isolate the proteins into highly concentrated corrals. All field-induced concentration profiles were completely reversible, indicating that the supported bilayer provides a stable, fluid environment in which GPI-tethered proteins can be manipulated. The ability to electrically control the spatial distribution of membrane-tethered proteins provides new opportunities for the study of biological membranes and the development of membrane-based devices.

Altered T cell receptor ligands trigger a subset of early T cell signals

TCR ligands are complexes of peptides and MHC proteins on the surfaces of APCs. Some of these ligands cause T cell proliferation (agonists), while others block it (antagonists). We compared the acid release, calcium flux, and proliferation response of helper T cells to a variety of ligands. We found that all agonist ligands but not most antagonist ligands trigger acid release, a general indicator of early cellular activation. Only a subset of ligands triggering acid release cause sustained calcium flux, and only a subset of these ligands cause T cell proliferation. Antagonist ligands and anti-CD4 antibodies both effectively block T cell proliferation. However, significantly greater antagonist ligand or antibody concentrations are required to block acid release and initial calcium influx. These data demonstrate a hierarchy of early T cell signaling steps and show that altered TCR ligands can initiate some steps while blocking the completion of others.