Novel ZEB1 expression in bladder tumorigenesis.

UNLABELLED: What's known on the subject? and What does the study add? Epithelial-mesenchymal transition (EMT) is involved in tumor progression where the underlying cellular changes associated with EMT have been identified in in vitro models and confirmed in a limited number of in vivo studies. ZEB1, which targets E-cadherin repression, is a transcriptional regulator that has been implicated in EMT, and is associated with uterine and colorectal cancers. Regulation of ZEB1 expression has been shown to involve different microRNAs (miRNAs), identifying a potential role for miRNA in EMT. In the present study we have identified novel expression of ZEB1 in bladder tumours and shown a role for ZEB1 in enhanced migration and invasion potential in in vitro assays. Confirmation of ZEB1 expression in bladder tumours was shown in tissue microarrays (TMAs). OBJECTIVE: To evaluate ZEB1 expression in bladder tumorigenesis and define a possible role for this transcription factor in urothelial carcinomas of the bladder (UCBs). MATERIALS AND METHODS: Five hundred and fifty-eight samples were assembled in 10 tissue microarrays (TMAs; 263 non-muscle-invasive Ta/T1/Tis, 295 muscle-invasive T2-T4). All tumours were transitional cell carcinomas (TCCs) and processed for immunohistochemistry to assess nuclear ZEB1 expression. Expression levels of ZEB1 were modulated in bladder carcinoma cell lines CUBIII or UM-UC-3 after forced expression or shRNA knockdown, respectively. Protein expression levels were determined using western blot analysis and transfectants were assessed for migration and invasion potential in standard in vitro assays. RESULTS: Nuclear ZEB1 expression was recorded in 22.8% of non-muscle-invasive UCBs and 21.7% of muscle-invasive UCBs, including 24.1% grade I/II and 21.1% grade III tumours, and absent in normal bladder mucosa. No significant correlation was observed for tumour stage and grade, nodal involvement, vascular invasion, metastasis and overall or cancer-specific survival. The introduction or knockdown of ZEB1 expression in bladder carcinoma cell lines showed enhanced or reduced migration and invasive potential, respectively. Changes in ZEB1 expression were accompanied by altered microRNA (miRNA) expression underlying events linked to epithelial-mesenchymal transition (EMT). CONCLUSION: The results in the present study showed novel expression of ZEB1 in bladder cancer in the absence of a link to clinical variables of change, including metastasis and survival. However, in vitro assays showed enhanced or reduced migration and invasion after the introduction or reduction of ZEB1, respectively, in transfected bladder cell lines. Modulation in expression of ZEB1 was closely linked to changes in the miR-200 family along with alternative known prognostic indicators of bladder tumour progression.

P-cadherin as a prognostic indicator and a modulator of migratory behaviour in bladder carcinoma cells.

OBJECTIVE: To identify changes associated with P-cadherin expression in bladder cancer and evaluate the potential role of such events in determining the clinical outcome and cell behaviour, as the function of P-cadherin in normal epithelium is unknown, as is its potential role in neoplastic progression in different cancers. MATERIALS AND METHODS: In all, 536 bladder tumour specimens from 408 patients were assembled in seven tissue microarrays. Paraffin sections from each array were processed for immunohistochemistry to assess the expression of P-cadherin. The expression of P-cadherin was forced using lipofectin, followed by an assessment of migration and invasion potential using standard in vitro assays. RESULTS: The absence of P-cadherin staining was associated with muscle-invasive disease, grade 3 (P < 0.001) and nodal disease (P = 0.009). Similar results were obtained when considering cytoplasmic and unrestricted localization of P-cadherin (P < 0.001), except for nodal involvement. The group with cytoplasmic location of P-cadherin showed a shorter cancer-specific survival than the group with membrane location of P-cadherin (P = 0.03). Forced expression of P-cadherin in EJ and UM-UC-3 cells, that constitutively lack P-cadherin expression, resulted in modulation of catenin expression and enhanced migration of EJ and UM-UC-3/P-cadherin transfectants (>200%). CONCLUSIONS: These results showed that loss of expression, cytoplasmic relocation or unrestricted tissue location of P-cadherin was associated with a poor clinical outcome and prognosis in bladder cancer. From the in vitro work it is evident that P-cadherin plays a role in regulating the migration potential of bladder carcinoma cells.

Prognostic significance of altered p120 ctn expression in bladder cancer.

OBJECTIVE: To identify the frequency of change in the expression and localization of p120(ctn) in bladder tumours and its association with clinical outcomes, and to investigate the potential role of p120(ctn) in the migratory and invasive behaviour of bladder carcinoma cells. MATERIALS AND METHODS: In all, 425 superficial tumour specimens (Ta, Tis and T1) and 305 invasive (T2-T4) tumour specimens from 534 patients were assembled in 10 tissue microarrays. P120(ctn) immunostaining was scored for intensity and cellular localization and correlated with clinical variables and survival analysis. Knockdown of p120(ctn) was achieved using small-interference RNA (siRNA) followed by the assessment of migration and invasion behaviour in standard in vitro assays. RESULTS: The expression levels of p120 catenin inversely correlated with pathological tumour stage (P < 0.001), histological grade (P < 0.001), presence of lymphovascular invasion (P = 0.02) but not lymph node (LN) involvement (P = 0.17). Non-membranous localization of p120(ctn) correlated with stage (P < 0.001), grade (P < 0.001), lymphovascular invasion (P = 0.04) and LN-positive disease (P = 0.02). A low expression level of p120(ctn) was linked to a poor outcome in cancer-specific survival analysis. Knockdown of p120(ctn) using siRNA resulted in a significant reduction in the migration and invasive potential of bladder carcinoma cells. CONCLUSIONS: Our findings suggest that p120(ctn) acts as a prognostic factor in bladder tumours and has a primary role to play in the migratory and invasive behaviour of bladder carcinoma cells.

Identification and prognostic significance of an epithelial-mesenchymal transition expression profile in human bladder tumors.

PURPOSE: Epithelial to mesenchymal transition (EMT) is reportedly an important transition in cancer progression in which the underlying cellular changes have been identified mainly using in vitro models. In this study, we examined the expression pattern of EMT markers in vivo and determined the occurrence and clinical significance of these events in a series of bladder carcinomas. EXPERIMENTAL DESIGN: Eight hundred and twenty-five tumor samples from 572 bladder cancer patients were assembled in 10 tissue microarrays. Paraffin sections from each tissue microarray were subjected to antigen retrieval and processed by immunohistochemistry for the expression of E-cadherin, plakoglobin, beta-catenin, N-cadherin, and vimentin. RESULTS: Pathologic expression of E-cadherin, beta-catenin, plakoglobin, and vimentin were associated with the clinicopathologic variables of grade and stage with only the cytoplasmic localization of plakoglobin found associated with lymph node status. Associations between the aforementioned markers were found significant as determined by the Spearman correlation coefficient with N-cadherin showing no associations in this analysis. In univariate survival analysis involving patients who underwent cystectomy, the reduction or loss of plakoglobin significantly influenced overall survival (P = 0.02) in which the median time to death was 2 years compared with 4 years when a normal level of plakoglobin was recorded. When the analysis was done for cancer-specific survival, low levels of both plakoglobin (P = 0.02) and beta-catenin (P = 0.02) significantly influenced survival. CONCLUSION: The putative markers of EMT defined within a panel of bladder carcinoma cell lines were recorded in vivo, frequently associated with tumors of high grade and stage. Although multivariate analysis showed no significant influence of the EMT biomarkers on survival, alterations associated with plakoglobin were identified as significant prognostic features in these tumors.

Evaluation of a novel reverse thermosensitive polymer for use in microvascular surgery.

Microvascular clamps have several potential shortcomings, including the risk of vessel injury. LeGoo, a novel reverse thermosensitive polymer (Pluromed Inc., Woburn, MA), is investigated as a substitute to vascular clamping in a microsurgical model and the technical details are described. Femoral vessels of Sprague Dawley rats were used to evaluate the usefulness of this polymer for performing end-to-end arterioarterial (AA), venovenous (VV), and end-to-side arteriovenous (AV) microvascular anastomoses. The ability to obtain and maintain hemostasis was assessed. Secondary endpoints, including polymer volume, concentration, temperature, infusion technique, ability to reinfuse, blood vessel stenting effect, polymer dissolution characteristics, and reestablishment of flow, were also noted. Initial hemostasis occurred in every case. Mean duration of efficacy (hemostasis) after initial injection was 17.8 minutes (4 minutes to 44.5 minutes) for AA anastomoses and 31.8 minutes (13 minutes to 46 minutes) for VV anastomoses. Mean volume of polymer initially injected was 0.11 mL (0.01 mL to 0.20 mL) and 0.07 mL (0.06 mL to 0.10 mL) for AA and AV arteries, respectively, and 0.14 mL (0.10 mL to 0.20 mL) and 0.20 mL (0.15 mL to 0.27 mL) for VV and AV veins. Use of LeGoo in veins was clearly superior to arterial use with regard to the technical aspects of injecting LeGoo and reestablishing hemostasis, as well as greater vessel stenting effect and less vessel retraction. This novel polymer showed promise for its ability to allow for hemostasis while performing microvascular anastomoses. Improvements were made with regard to injection techniques, appropriate volumes, ability to reliably determine gel plug dissolution, and final vessel patency. Preliminary results demonstrate that this polymer may be a viable substitute for microvascular clamps.

Experimental validation of peptide immunohistochemistry controls.

Peptide immunohistochemistry (IHC) controls are a new quality control format for verifying proper IHC assay performance, offering advantages in high throughput automated manufacture and standardization. We previously demonstrated that formalin-fixed peptide epitopes, covalently attached to glass microscope slides, behaved (immunochemically) in a similar fashion to the native protein in tissue sections. To convert this promising idea into a practical clinical laboratory quality control tool, we tested the hypothesis that the quality assurance information provided by peptide IHC controls accurately reflects IHC staining performance among a diverse group of clinical laboratories. To test the hypothesis, we first designed and built an instrument for reproducibly printing the controls on microscope slides and a simple software program to measure the color intensity of stained controls. Automated printing of peptide spots was reproducible, with coefficients of variation of 4% to 8%. Moreover, the peptide controls were stable at