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N-cadherin is a transmembrane glycoprotein expressed by mesenchymal origin cells and is located at the adherens junctions. It regulates also cell motility and contributes to cell signaling. In previous studies, we identified that its anomalous expression in bladder carcinoma was a tumor progression marker. A pharmacological approach to inhibit N-cadherin expression or to block its function could be relevant to prevent disease progression and metastasis development. The morphological exploration of T24 invasive bladder cancer cells by atomic force microscopy (AFM) revealed a spindle-like shape with fibrous structures. By engaging force spectroscopy with AFM tip functionalized with anti-E or anti-N-cadherin antibodies, results showed that T24 cells expressed only N-cadherin as also demonstrated by Western blotting and confocal microscopy. For the first time, we demonstrated by RTqPCR and Western blotting analyses that the peroxisome proliferator-activated receptor β/δ (PPARβ/δ) agonist GW501516 significantly decreased N-cadherin expression in T24 cells. Moreover, high non-cytotoxic doses of GW501516 inhibited confluent T24 cell wound healing closure. By using AFM, a more sensitive nanoanalytical method, we showed that the treatment modified the cellular morphology and diminished N-cadherin cell surface coverage through the decreasing of these adhesion molecule-mediated interaction forces. We observed a greater decrease of N-cadherin upon GW501516 exposure with AFM than that detected with molecular biology techniques. AFM was a complementary tool to biochemical techniques to perform measurements on living cells at the nanometer resolution level. Taken together, our data suggest that GW501516 could be an interesting therapeutic strategy to avoid bladder cancer cell spreading through N-cadherin decrease.

Background: Non-muscle invasive bladder cancers (NMIBC: pTa, pT1) are characterised by a high risk of recurrence and/or progression. Identification of prognostic markers is needed to improve both diagnosis and management of the disease. The aim of this study was to analyse the expression of A-FABP (adipocyte-fatty acid binding protein) and to evaluate its prognostic value in bladder cancer with a long term clinical follow-up., Methods: A-FABP expression was investigated by immunohistochemistry in 236 tumours (114 pTa, 61 pT1, 61 pT2-4). Immunostaining was classified as negative (absent or weak immunostaining and moderate or strong staining on ≤10% of cells) or positive (moderate or strong staining on > 10% of cells). Event-free survival (EFS) and overall survival (OS) were determined with a 87.3 months median follow-up in the overall cohort. Recurrence-free survival (RFS) and progression-free survival (PFS) were established in NMIBC., Results: Loss of A-FABP was associated with higher mean age, high stage/grade, and the presence of metastatic lymph nodes. It was correlated with shorter median EFS (17.5 vs 62.5 months; p = 0.001) and mean OS (76.7 vs 154.2 months; p = 0.009) and with higher risk of progression in the pTa/pT1 subgroup (HR, 0.36; 95% CI, 0.13-0.96; p = 0.041) and importantly in the pTa tumours (HR, 0.34; 95% CI, 0.10-0.97; p = 0.045)., Conclusion: These results demonstrated that loss of A-FABP expression following a long follow-up was predictive of pTa and pTa/pT1 progression. Immunohistochemistry on diagnostic biopsy is easy to use and could be of value to help clinicians to propose appropriate treatment for these tumours.

GW501516 is a selective and high-affinity synthetic agonist of peroxisome proliferator-activated receptor β/δ (PPARβ/δ). This molecule promoted the inhibition of proliferation and apoptosis in few cancer cell lines, but its anticancer action has never been investigated in bladder tumor cells. Thus, this study was undertaken to determine whether GW501516 had antiproliferative and/or apoptotic effects on RT4 and T24 urothelial cancer cells and to explore the molecular mechanisms involved. Our results indicated that, in RT4 cells (derived from a low-grade papillary tumor), GW501516 did not induce cell death. On the other hand, in T24 cells (derived from an undifferentiated high-grade carcinoma), this PPARβ/δ agonist induced cytotoxic effects including cell morphological changes, a decrease of cell viability, a G2/M cell cycle arrest, and the cell death as evidenced by the increase of the sub-G1 cell population. Furthermore, GW501516 triggered T24 cell apoptosis in a caspase-dependent manner including both extrinsic and intrinsic apoptotic pathways through Bid cleavage. In addition, the drug led to an increase of the Bax/Bcl-2 ratio, a mitochondrial dysfunction associated with the dissipation of ΔΨm, and the release of cytochrome c from the mitochondria to the cytosol. GW501516 induced also ROS generation which was not responsible for T24 cell death since NAC did not rescue cells upon PPARβ/δ agonist exposure. For the first time, our data highlight the capacity of GW501516 to induce apoptosis in invasive bladder cancer cells. This molecule could be relevant as a therapeutic drug for high-grade urothelial cancers.

Background: Ciglitazone belongs to the thiazolidinediones class of antidiabetic drug family and is a high-affinity ligand for the Peroxisome Proliferator-Activated Receptor γ (PPARγ). Apart from its antidiabetic activity, this molecule shows antineoplastic effectiveness in numerous cancer cell lines., Methodology/principal Findings: Using RT4 (derived from a well differentiated grade I papillary tumor) and T24 (derived from an undifferentiated grade III carcinoma) bladder cancer cells, we investigated the potential of ciglitazone to induce apoptotic cell death and characterized the molecular mechanisms involved. In RT4 cells, the drug induced G2/M cell cycle arrest characterized by an overexpression of p53, p21(waf1/CIP1) and p27(Kip1) in concomitance with a decrease of cyclin B1. On the contrary, in T24 cells, it triggered apoptosis via extrinsic and intrinsic pathways. Cell cycle arrest and induction of apoptosis occurred at high concentrations through PPARγ activation-independent pathways. We show that in vivo treatment of nude mice by ciglitazone inhibits high grade bladder cancer xenograft development. We identified a novel mechanism by which ciglitazone kills cancer cells. Ciglitazone up-regulated soluble and membrane-bound TRAIL and let TRAIL-resistant T24 cells to respond to TRAIL through caspase activation, death receptor signalling pathway and Bid cleavage. We provided evidence that TRAIL-induced apoptosis is partially driven by ciglitazone-mediated down-regulation of c-FLIP and survivin protein levels through a proteasome-dependent degradation mechanism., Conclusions/significance: Therefore, ciglitazone could be clinically relevant as chemopreventive or therapeutic agent for the treatment of TRAIL-refractory high grade urothelial cancers.

Thiazolidinediones, including rosiglitazone and troglitazone, are insulin-sensitizing drugs and high-affinity ligands for the peroxisome proliferator-activated receptor gamma (PPARgamma). Apart from their antidiabetic activity, these molecules possess antitumor properties. We investigated their potential apoptotic effects on RT4 (derived from a well-differentiated Grade I papillary tumor) and T24 (derived from an undifferentiated Grade III carcinoma) bladder cancer cells. Rosiglitazone induced G2/M or G0/G1 phase cell cycle arrest in RT4 and T24 cells, respectively. Only troglitazone triggered apoptosis via extrinsic and intrinsic pathways in both cell lines. Interestingly, rosiglitazone amplified TRAIL-induced apoptosis in TRAIL-sensitive RT4 cells or let TRAIL-resistant T24 cells to respond to TRAIL. Thiazolidinediones acted through PPARgamma activation-independent mechanisms. The underlying mechanisms involved for the first time in cancer cells the upregulation of soluble and/or membrane-bound TRAIL. This was associated with increased cell surface death receptor 5 expression and c-FLIP and survivin downregulation, mediated in part through proteasome-dependent degradation in troglitazone-promoted cell death. Therefore, the combination of rosiglitazone and TRAIL could be clinically relevant as chemopreventive or therapeutic agents for the treatment of TRAIL-resistant high-grade urothelial cancers.

Objectives: A particular interest in epithelial-mesenchymal transition (EMT), which takes place during embryonic development, provided potential mechanisms involved in the progression of many epithelial tumors, including bladder cancer (BC). The phospho-Akt signaling pathway is supposed to be involved in invasion and progression of human tumors, including BC. Moreover, it has been demonstrated in bladder cancer cell lines that N-cadherin or phospho-epithelial growth factor receptor (EGFR) expression are correlated to tumor progression. Our objectives were to evaluate the potential phospho-Akt pathway involvement in N-cadherin and/or phospho-EGFR positive BC cell lines and to evaluate the prognostic value of E- and N-cadherin expression in patients undergoing cystectomy for invasive BC., Materials and Methods: We screened a panel of invasive and noninvasive BC cell lines for E- and N-cadherin, phospho-EGFR, and phospho-Akt expression using the Western blot technique (WB). The potential role of N-cadherin in invasion was assessed by Matrigel assays with and without the N-cadherin blocking monoclonal antibody GC-4. Then we used the Affymetrix microarray technique to evaluate the prognostic value of E- and N-cadherin expression in 30 patients undergoing a cystectomy for invasive BC., Results: N-cadherin and phospho-EGFR expression are associated with Akt activation and with invasive behavior modulation. Even if Akt activation is sufficient in promoting invasion, its inactivation by LY294002 (PI-3 kinase inhibitor) is less efficient on invasion than inhibition of N-cadherin and phospho-EGFR by GC-4 (monoclonal antibody) and gefitinib (anti-tyrosine kinase), respectively. N-cadherin and phospho-EGFR inhibition decreased phospho-Akt activation but also caused restoration and reinforcing of E-cadherin expression, respectively, while phospho-Akt inhibition did not have any impact on E-cadherin expression. In a group of high-risk bladder tumors (T(1)G(3)), N- and E-cadherin expression could be considered as a prognostic marker. In a group of patients with invasive BC (pT(2)-T(4)) undergoing cystectomy, we showed a shorter overall survival when BC expressed N-cadherin (P = 0.0064) and when E-cadherin expression was down-regulated (P = 0.00165). The N (positive) /E (negative) profile has the worst prognosis (P = 0.00153)., Conclusions: We confirmed the partial responsibility of p-Akt activation in invasion of some BC cell lines expressing N-cadherin or p-EGFR and also the potential role of N-cadherin and p-EGFR as target in cancer therapy. N/E- cadherin expression profile has a significant prognostic value in invasive BC., (Copyright 2010 Elsevier Inc. All rights reserved.)

The present investigation was conducted first to determine whether correlation exists between VEGF-A and -B mRNA levels and clinicopathological parameters and to assess their prognostic value in bladder cancer, then to clarify the expression level and biological significance of VEGF-A isoforms. Total RNA was isolated from 37 specimens of bladder cancer. Northern blot analysis revealed that VEGF-B mRNA was not expressed either in normal urothelium or in bladder cancer and detected three VEGF-A transcripts of 5.2, 4.5 and 1.7 kb in length, respectively. The VEGF-A transcript levels were greater in cancer tissues than in normal urothelium. They were significantly higher in pT2-T4 than in pTa and pT1 urothelial tumors and thus, were correlated to the pathologic stage. Contrary to the 4.5 kb transcript, elevated expression of the 5.2 and 1.7 kb transcripts was correlated with the histologic grade and the presence of carcinoma in situ. Patients with higher VEGF-A mRNA levels had a significantly shorter survival without progression compared to those with lower levels. Three VEGF-A splice variants were detected by southern blotting namely, VEGF121, 165 and 189. The expression intensity of each isoform was evaluated by quantitative real-time RT-PCR in 20 new fresh frozen recent tumors. VEGF121 and VEGF165 were expressed at the similar level. On the contrary, they were significantly more expressed than VEGF189 (p<0.05). The three isoforms were higher expressed in pT2 bladder cancers than in pTa tumors (p<0.05). There was only a significant correlation between the increased expression level of VEGF121 and 165 and the histological grade of the lesion (p<0.05). To conclude, VEGF-A mRNA level is a potential prognostic indicator of progression in bladder cancer as well as the expression level of the different VEGF-A splice variants.

Objectives: Twist is considered as transcription factor that regulates epithelial mesenchymal transition (EMT) by at least inhibition of E-cadherin expression. EMT is a key event in the tumor invasion process. The purpose of this study is to investigate the expression of Twist but also those of E- and N-cadherin in human primary bladder tumor and to evaluate its prognostic value. As smoking cigarettes is a strong bladder cancer risk factor, we tried to evaluate the impact of the tobacco status on these molecular abnormalities., Materials and Methods: To delineate on the oncogenic role for Twist in human bladder cancer, we evaluated the E- and N-cadherin but also Twist expression (n = 70) by immunohistochemistry. We evaluated the prognostic value of these expressions. Moreover, we tried to correlate these protein expressions to the smoking status of the patients. Overall survival (OS) and progression-free survival (PFS) were evaluated using the Kaplan-Meier method, and multivariate analysis was performed using the Cox proportional hazard analysis., Results: Of the 70 bladder tumors, 28 (40%) cases were positive for Twist expression, 16 (23%) cases were negative for E-cadherin expression, and 12 (17%) were positive for N-cadherin expression. When categorized into negative vs. positive expression, Twist was associated with the stage (P = 0.001), the grade (P < 0.001), the progression (P = 0.02), and the E-cadherin expression (P = 0.01). Moreover, positive Twist expression clearly predicted poorer PFS (P = 0.02). In the multivariate analysis, both positive Twist expression and loss of E-cadherin expression were independent prognostic factors for PFS (P = 0.046 and P = 0.001, respectively) and only loss of E-cadherin expression for the OS (P < 0.001). We also demonstrated that almost 60% (16/28) of patients with Twist-positive expression were current smokers at the time of the diagnosis, corroborating the fact that smoking modulates the expression of EMT markers including Twist., Conclusion: Positive Twist expression may be a useful prognostic marker for patients with bladder cancer. Its expression seems to be correlated to the tobacco status of the patients.

Superficial pT1 bladder tumors are characterized by a high risk of recurrence and progression in grade and stage. Few studies provided evidence that loss of adipocyte-fatty acid binding protein (A-FABP) expression was associated with bladder cancer progression. A-FABP is a lipid binding protein playing a role in intracellular lipid transport and metabolism, as well as in signal transduction. We reported from bladder tumors that decrease of A-FABP transcript level significantly correlated to tumor stage and to histologic grade (p < 0.05). Namely, in poor prognosis high grade pT1 tumors there was a loss of A-FABP expression compared to good prognosis tumors suggesting that re-expression of A-FABP could be a therapeutic approach in early stage bladder cancer to prevent disease progression. We demonstrated for the first time that this marker is upregulated by Peroxisome Proliferator-Activated Receptor (PPAR) alpha, beta and gamma in T24 cells (derived from an undifferentiated grade III carcinoma) and only by PPARbeta in RT4 cells (derived from a well differentiated grade I papillary tumor). This effect occurred through a PPAR-dependent transcriptional mechanism without modifying mRNA stability and interestingly required de novo protein synthesis. Data as a whole suggest a prognostic significance of A-FABP in bladder cancer outcome and the potential utility of overexpression of this protein by PPAR agonists open up new perspectives in the treatment of bladder cancer. (c) 2008 Wiley-Liss, Inc.

Introduction: The incidence of genitourinary tumors (GUT) in renal transplant recipients (RTR) is higher than in the general population. We previously reported that CD4 lymphocytopenia is associated with a high incidence of skin cancer in RTR. Here, we investigate whether persistent CD4 T cell lymphopenia is associated with GUT occurrence., Patients and Methods: A total of 433 patients were included in this study. All patients underwent annually systematic lymphocyte subset (CD3, CD4, CD8, CD19) determination by flow cytometry., Results and Conclusion: During the follow-up period, 13 patients developed GUT: 6 patients a prostate adenocarcinoma (incidence 0.06%/year) and 7 patients a renal cell carcinoma (incidence 0.07%/year). The patients with GUT were older than those without. Both groups did not differ in posttransplant duration, dialysis mode and duration, induction regimen, or acute rejection history. No persistent CD4 lymphopenia was observed in the patients with GUT. Although CD4 T cell lymphopenia is associated with skin cancer in long-term RTR, it did not appear to be a risk factor for GUT. This suggests that other factors encountered in the setting of kidney transplantation (e.g., immunosuppressive drugs, end-stage renal failure, etc.) favor the development of GUT in RTR., (2008 S. Karger AG, Basel)

Purpose: Loss of intercellular adhesion and increased cell motility promote tumor cell invasion and spreading. In bladder cancer, loss or reduced E-cadherin expression has been associated with poor survival, and aberrant expression of N-cadherin has been associated with the invasive phenotype of bladder carcinoma cells. The purpose of this study was to investigate whether N-cadherin expression was associated with the bladder tumor progression., Experimental Design: E-cadherin and N-cadherin expression was evaluated by immunohistochemistry in 101 tumors (pT1 and pT2-T3) and by reverse transcription-PCR analysis and immunohistochemistry in 28 other fresh frozen tumors (pT(a), pT1, and pT2-T3)., Results: N-cadherin expression was absent in normal urothelium, appeared in stage pT1, and increased in pT2-pT3 tumors. In most cases, increased N-cadherin expression in invasive tumors was associated with loss of E-cadherin expression. Progression-free survival and multivariate analyses revealed that N-cadherin expression is an independent prognostic marker for pT1 tumor progression. Analysis of the 28 frozen tumors by immunohistochemistry and reverse transcription-PCR showed a good correlation between protein and gene expression in pT1 and pT2-T3 tumors. Interestingly, in pT(a) tumors, N-cadherin was not immunodetected, whereas mRNA was present in 50% of cases., Conclusion: Regulatory defects in the N-cadherin promoter, abnormalities at the translational, or protein processing levels could explain the discrepancies between protein and mRNA expression. Most importantly, this study identified N-cadherin as a novel prognostic marker of progression in superficial urothelial tumors. Clearly, N-cadherin acts in an invasive mode in bladder cancer, but whether it has a primary role in urothelial neoplastic progression has yet to be investigated.

Loss of intercellular adhesion facilitates tumor invasion. To clarify the relation between altered expression of cell adhesion molecules and progression of T1 superficial bladder tumors, 101 cases (71 T1 tumors, 30 T2/T3 tumors) were examined immunohistochemically for E-cadherin and alpha-, beta-, and gamma-catenins. A highly significant correlation was observed between the decreased expression of all molecules and increased TNM stage (P < .001). Univariate analysis, performed in cases of T1 tumors, revealed association of abnormal E-cadherin with beta-catenin diminution. Survival curves were established with the Kaplan-Meier method and analyzed according to clinical and histopathologic parameters using the log-rank test. Cox multivariate analysis revealed only gamma-catenin as an independent predictor of progression-free survival in patients with stage T1 bladder urothelial tumors. The characterization of T1 tumors that will progress could lead to the identification of patients who might benefit from surgery to avoid vesical muscle invasion and, consequently, metastasis.

We report a case of intravesical bladder leiomyoma in a 47-year-old patient presenting with recurrent macroscopic haematuria. The diagnosis was strongly suspected on CT and cystoscopy. Treatment consisted of transurethral resection of the mass. No recurrence has been observed with a follow-up of two years. In the light of this case, the authors discuss the diagnosis and treatment of bladder leiomyoma.

Smoking is a major risk factor for urothelial cell carcinoma of the bladder (UCC). Mutations in the FGFR3 and TP53 genes have been shown to define two distinct pathways in superficial papillary and invasive UCC disease, respectively. We investigated the relationship between smoking and these mutations by means of denaturing high performance liquid chromatography and sequencing for 110 primary UCC of the bladder. This study included 48 current smokers, 31 ex-smokers and 31 non-smokers. Thirty-five of the tumors were stage pTa, 40 pT1 and 35 > or =pT2. Fourteen of the tumors were grade 1, 37 were grade 2 and 59 grade 3. Smoking was associated with high stage (P = 0.03) and high grade tumors (P = 0.006). Twenty-two of the 110 tumors studied harbored TP53 mutations (20%) and 43 harbored FGFR3 mutations (39%). Odds ratios (OR) were higher for TP53 mutations in current smokers [OR, 2.25; 95% confidence interval (95% CI), 0.65-7.75] and ex-smokers (OR, 1.62; 95% CI, 0.41-6.42) than in non-smokers. Double TP53 mutations and the A:T-->G:C TP53 mutation pattern was found only in current smokers. Patients with the FGFR3(wild-type)/TP53(mutated) genotype had significantly higher levels of tobacco consumption, as measured in pack-years (P = 0.01). Smoking influenced neither the frequency nor the pattern of FGFR3 mutations. Our results suggest that smoking is associated with invasive and high grade UCCs, at initial presentation, and influenced TP53 or the molecular pathway defined by these mutations. In contrast, FGFR3 mutations are not affected by smoking and probably result from endogenous alterations. These data have potential implications for clinical management and prevention strategies.

Frequent deletions on 9q34.1-2 were reported in bladder transitional cell carcinoma. High deletion mapping studies delimited a critical interval between markers D9S61 and D9S66, which is highly susceptible to contain a tumor suppressor gene. Expression level of the 65 genes localized in this region was analyzed by real-time quantitative RT-PCR, comparing tumor to normal urothelium. Five genes exhibited a significantly reduced expression level: C9orf9, KIAA0625, ABL1, LAMC3 and KIAA1857-netrin-G2, which exhibited the most significant downregulation (p=0.0007). KIAA1857-netrin-G2 belongs to the netrins and might then be a tumor suppressor gene in bladder cancer, as netrin1 receptor DCC has been implicated in tumorigenesis., (Copyright 2004 Wiley-Liss, Inc.)

Objective: Comparison of the various treatment protocols for bladder cancer requires identification of survival prognostic factors. Some clinical parameters, such as tumour sub-site, have still not been studied. The authors therefore analysed the prognostic value of this factor, in combination with known prognostic factors, after radical cystectomy for urothelial bladder tumour., Materials and Method: 120 patients were treated for pure urothelial bladder tumour with pelvic lymphadenectomy, between January 1980 and January 1999, in a single centre. The prognostic value of the various sub-sites was studied by univariate and multivariate survival analysis., Results: The 5-year survival decreased from 62% to 19% in the case of a lesion involving the bladder dome (p = 0.0001). Multivariate analysis demonstrated the following independent prognostic factors: local invasion pT < or = 3 (p = 0.003), lymph node involvement (p = 0.05) and involvement of the dome (p = 0.002). Other tumour sub-sites had an effect on survival on univariate analysis that was not confirmed on multivariate analysis., Conclusion: Although stages pT and pN are prognostic factors recognized by all studies, invasion of the bladder dome appears to have a major independent influence on survival. This result must be confirmed by other studies, in view of its potential influence for determination of homogeneous patient groups in controlled trials.

The growth of any solid tumor depends on angiogenesis. Vascular endothelial growth factor (VEGF) plays a prominent role in vesical tumor angiogenesis regulation. Previous studies have shown that the peroxisome proliferator-activated receptor gamma (PPARgamma) was involved in the angiogenesis process. Here, we report for the first time that in two different human bladder cancer cell lines, RT4 (derived from grade I tumor) and T24 (derived from grade III tumor), VEGF (mRNA and protein) is differentially up-regulated by the three PPAR isotypes. Its expression is increased by PPARalpha, beta, and gamma in RT4 cells and only by PPARbeta in T24 cells via a transcriptional activation of the VEGF promoter through an indirect mechanism. This effect is potentiated by an RXR (retinoid-X-receptor), selective retinoid LG10068 providing support for a PPAR agonist-specific action on VEGF expression. While investigating the downstream signaling pathways involved in PPAR agonist-mediated up-regulation of VEGF, we found that only the MEK inhibitor PD98059 reduced PPAR ligand-induced expression of VEGF. These data contribute to a better understanding of the mechanisms by which PPARs regulate VEGF expression. They may lead to a new therapeutic approach to human bladder cancer in which excessive angiogenesis is a negative prognostic factor.