Evaluation of epidermal growth factor receptors in bladder tumours

Tumor spheroid invasion in epidermal growth factor gradients revealed by a 3D microfluidic device

Epidermal growth factor (EGF), a potent cytokine, is known to promote tumor invasion bothin vivoandin vitro. Previously, we observed that single breast tumor cells (MDA-MB-231 cell line) embedded within a 3D collagen matrix displayed enhanced motility but no discernible chemotaxis in the presence of linear EGF gradients using a microfluidic platform. Inspired by a recent theoretical development that clustered mammalian cells respond differently to chemical gradients than single cells, we studied tumor spheroid invasion within a 3D extracellular matrix (ECM) in the presence of EGF gradients. We found that EGF gradients promoted tumor cell detachment from the spheroid core, and the position of the tumor spheroid core showed a mild chemotactic response towards the EGF gradients. For those tumor cells detached from the spheroids, they showed an enhanced motility response in contrast to previous experimental results using single cells embedded within an ECM. No discernible chemotactic response towards the EGF gradients was found for the cells outside the spheroid core. This work demonstrates that a cluster of tumor cells responds differently than single tumor cells towards EGF gradients and highlights the importance of a tumor spheroid platform for tumor invasion studies.

Role of tyrosine kinases in bladder cancer progression: an overview

Background

Bladder cancer (BCa) is a frequent urothelial malignancy with a high ratio of morbidity and mortality. Various genetic and environmental factors are involved in BCa progression. Since, majority of BCa cases are diagnosed after macroscopic clinical symptoms, it is required to find efficient markers for the early detection. Receptor tyrosine-kinases (RTKs) and non-receptor tyrosine-kinases (nRTKs) have pivotal roles in various cellular processes such as growth, migration, differentiation, and metabolism through different signaling pathways. Tyrosine-kinase deregulations are observed during tumor progressions via mutations, amplification, and chromosomal abnormalities which introduces these factors as important candidates of anti-cancer therapies.

Main body

For the first time in present review we have summarized all of the reported tyrosine-kinases which have been significantly associated with the clinicopathological features of BCa patients.

Conclusions

This review highlights the importance of tyrosine-kinases as critical markers in early detection and therapeutic purposes among BCa patients and clarifies the molecular biology of tyrosine-kinases during BCa progression and metastasis.

Effects of miR‑138‑5p and miR‑204‑5p on the migration and proliferation of gastric cancer cells by targeting EGFR

GC (gastric cancer) remains one of the most lethal malignancies worldwide. EGFR (epidermal growth factor receptor) plays an important role in the malignant process of GC, therefore, the present study addressed the relationship between EGFR and its potential regulators and examined their regulatory mechanisms in GC. We examined differences in the expression levels of EGFR in GC and adjacent non‑cancerous tissues. Bioinformatics analyses and dual luciferase reporter assays were used to confirm the putative relationship between miR‑138 or miR‑204 and EGFR, and their relationship was further detected using western blotting, RT‑PCR, and a series of cell studies. EGFR proteins were abundantly expressed in GC tissues, however EGFR mRNA levels remained indistinctive. Consequently, EGFR was revealed as a putative target of miR‑138 and miR‑204 which bound to the 3'UTR of EGFR mRNA. Further analysis revealed that miR‑138 and miR‑204 were significantly downregulated in GC tissues and the overexpression of miR‑138 and miR‑204 in GC cell lines resulted in the significant inhibition of EGFR protein levels and GC cell proliferation and metastasis. Rescue experiments confirmed that the roles of the two microRNAs were specific to EGFR. EGFR is a pivotal oncogene in GC progression that may be regulated by miR‑138 and miR‑204.

Epidermal Growth Factor Receptor in Human Breast Cancer: Comparison with Steroid Receptors and other Prognostic Factors

The relationship between epidermal growth factor receptor (EGFR) status and various prognostic factors was investigated in 70 human breast cancer specimens. Epidermal growth factor receptor was determined by radioligand binding assay, standardized by the EORTC Receptor Study Group, using hydroxyapatite to separate receptor-bound and free ligand. The percentage of EGFR positivity was 80% when the cutoff was set at 5 fmol/mg of membrane protein; this percentage was among the highest hitherto reported. Regression analysis of EGFR versus ER and PR levels confirmed an inverse relationship between EGFR and ER (p = 0.022) as well as between EGFR and PR (p = 0.024). Univariate analysis of the EGFR data stratified according to steroid hormone receptor status showed EGFR to be negatively associated with ER and PR. No association was found between EGFR and menopausal status, axillary lymph node involvement, tumor size, and differentiation grade. A direct association between EGFR status and Ki-67 positive cell rate could be demonstrated.

Sleeping beauty: awakening urothelium from its slumber

The bladder urothelium is essentially quiescent but regenerates readily upon injury. The process of urothelial regeneration harkens back to the process of urothelial development whereby urothelial stem/progenitor cells must proliferate and terminally differentiate to establish all three urothelial layers. How the urothelium regulates the level of proliferation and the timing of differentiation to ensure the precise degree of regeneration is of significant interest in the field. Without a carefully-orchestrated process, urothelial regeneration may be inadequate, thereby exposing the host to toxins or pathogens. Alternatively, regeneration may be excessive, thereby setting the stage for tumor development. This review describes our current understanding of urothelial regeneration. The current controversies surrounding the identity and location of urothelial progenitor cells that mediate urothelial regeneration are discussed and evidence for each model is provided. We emphasize the factors that have been shown to be crucial for urothelial regeneration, including local growth factors that stimulate repair, and epithelial-mesenchymal cross talk, which ensures feedback regulation. Also highlighted is the emerging concept of epigenetic regulation of urothelial regeneration, which additionally fine tunes the process through transcriptional regulation of cell cycle genes and growth and differentiation factors. Finally, we emphasize how several of these pathways and/or programs are often dysregulated during malignant transformation, further corroborating their importance in directing normal urothelial regeneration. Together, evidence in the field suggests that any attempt to exploit regenerative programs for the purposes of enhanced urothelial repair or replacement must take into account this delicate balance.

Human epidermal growth factor receptor 2/neu overexpression in urothelial carcinoma of the bladder and its prognostic significance: Is it worth hype?

Aims:

In urothelial tumors of the urinary bladder, human epidermal growth factor receptor 2 (HER-2)/neu expression has been reported over 10 years, but there is no clear correlation between prognosis and recurrence rate. The present study evaluates prognostic implication of HER-2/neu expression.

Subjects and Methods:

In this study, 100 formalin-fixed paraffin-embedded specimens of primary transitional cell carcinoma of the bladder were processed. HER-2/neu monoclonal antibody immunohistochemistry staining procedure used for the study.

Results:

A total of 70 (70%) patients were positive for overexpression of HER-2/neu. HER-2/neu was positive in patients with 42 (70%) superficial tumor, 28 (70%) muscle invasive tumor, 41 (75.9%) high-grade tumor, 29 (63%) low grade tumor, 31 (68.9%) recurrent tumor, and 6 (66.6%) had positive lymph nodes.

Conclusions:

Human epidermal growth factor receptor 2/neu over expression was not correlated with the tumor stage, lymphnode metastasis or recurrence of the disease. HER-2/neu overexpression was statistically insignificantly correlated with the differentiation grade (P < 0.161) as compared to previous studies. Future studies on HER-2 expression with chemo-sensitivity and efficacy of HER-2-targeted therapies in urothelial carcinomas is needed.

Markers of bladder cancer State of the art

Biomarkers are increasingly being applied to the clinical management of patients with bladder cancer. The biomarkers in current clinical use focus on bladder cancer detection. Biomarkers for prognosis and as intermediate endpoints for chemoprevention are being evaluated in clinical trials. This review provides an overview of the performance characteristics of current clinical markers and other markers that are currently under evaluation.

Recent advances in treatment of advanced urothelial carcinoma

GC (cisplatin and gemcitabine) and MVAC (methotrexate, vinblastine, Adriamycin [doxorubicin], and cisplatin) have been the standard systemic chemotherapy in advanced urothelial carcinoma. These regimens have shown significant response rates in this patient population. Nevertheless, disease does recur with most patients who unfortunately do succumb to the disease. Research efforts are focused in several different areas of therapy, targeted therapy, and immunotherapy. Further efforts include those in improving understanding of the molecular biology of urothelial carcinoma which may lead development of biomarkers that may enhance therapeutic index. This paper reviews recent advances in the treatment and ongoing study of molecular biology of urothelial carcinoma.

Current treatment of metastatic bladder cancer and future directions

Metastatic urothelial carcinoma portends a very poor long-term prognosis, with 5-year survival at approximately 5%. The overall survival of metastatic bladder cancer has not improved over the last 20 years. The first-line therapy is cisplatin-based chemotherapy with the response rate approximately 50%. Approximately 30-50% of the patients are unsuitable for cisplatin, and there is no standard of care for this patient population. There is no standard second-line treatment. Several signaling pathways are activated in bladder urothelial carcinoma, but no targeted therapy, either alone or in combination with conventional cytotoxic chemotherapy, has been shown to significantly improve the treatment outcomes. The future of metastatic urothelial carcinoma treatment lies in the ability to deliver personalized therapy. This area remains an active research field today.

Over-expression of HER-2 is associated with the stage in carcinomas of the urinary bladder

BACKGROUND

The frequency of over-expression of human epidermal growth factor receptor-2 (HER-2) in bladder cancer is one of the highest among all human malignancies. This over-expression is thought to play a role in aberrant proliferation of cancer cells. Studies on HER-2 expression in bladder carcinoma have shown heterogeneous results.

PURPOSE

The aim of the study was to evaluate the status of HER-2 protein expression in patients with invasive carcinomas of the urinary bladder as related to tumor grade and stage.

MATERIALS AND METHODS

Archival samples from 39 patients (6 women, 33 males) with urinary bladder cancer were analyzed for HER-2 over-expression, using immunohistochemistry with the HercepTest.

RESULTS

HER-2 over-expression was observed in 23/39 tumors (59%) and was more frequent in high-grade than in low-grade carcinomas, but the difference was not statistically significant. A significant correlation was established between HER-2 over-expression and tumor stage (p=0.011). HER-2 expression was more frequent in transitional cell carcinomas (TCC) and adenocarcinomas (AC) as compared with squamous cell carcinoma (SCC). Patients' age and sex were not related to HER-2 over-expression.

CONCLUSION

Over-expression of HER-2 was frequent in carcinomas of the urinary bladder. Knowing the HER-2 status would be helpful in formulating a rational treatment strategy for patients with urinary bladder cancer.

Emerging therapies for urothelial cancer

Urothelial carcinoma is one of the leading causes of death in Europe and the United States. Despite its chemosensitivity, median overall survival for advanced disease is still nearly 1 year. Most second-line chemotherapeutic agents tested have been disappointing. Thus, new treatment strategies are clearly needed. This review focuses on emerging therapies in urothelial carcinoma. Results from recent clinical trials, investigating the activity of new generation cytostatic agents, as well as results from studies assessing the toxicity and efficacy of novel targeted therapies, are discussed. In this setting, anti-epidermal growth factor receptor, angiogenesis, and phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitors account for the majority of phase I and II trials.

Targeted proteomic analysis of 14-3-3sigma in nasopharyngeal carcinoma

14-3-3sigma is a potential tumor suppressor, and loss of 14-3-3sigma expression plays an important role in carcinogenesis and metastasis. To explore the possible mechanism of 14-3-3sigma in nasopharyngeal carcinoma (NPC) invasion and metastasis, targeted proteomic analysis was performed on 14-3-3sigma-associated proteins from NPC cells. As the results, 112 proteins associated with 14-3-3sigma were identified, and four 14-3-3sigma-interacted proteins: keratin 8, epidermal growth factor receptor (EGFR), small GTP-binding protein RAB7, and p53 were confirmed by coimmunoprecipitation and Western blot analysis. The 14-3-3sigma-associated proteins could be grouped into eight clusters based on their molecule functions. Protein-protein interaction (PPI) analysis indicated that 14-3-3sigma/EGFR/keratin 8 interactions may be involved in the invasion and metastasis of NPC. 14-3-3sigma/EGFR/keratin 8 could form complexes in NPC cells. 14-3-3sigma downregulation in NPC may lead to the overexpression of EGFR and keratin 8, which increases the invasion ability of NPC cells possibly by activating the downstream signal molecules and reorganizing cytoskeleton. The data suggest that the biological functions of 14-3-3sigma in NPC are diversified, and 14-3-3sigma could inhibit the in vitro invasive ability of NPC cells possibly through 14-3-3sigma/EGFR/keratin 8 interaction.

Human rhomboid family-1 gene RHBDF1 participates in GPCR-mediated transactivation of EGFR growth signals in head and neck squamous cancer cells

Epidermal growth factor receptor (EGFR) is an activated oncogene in many cancers. It can be transactivated by ligands of G protein-coupled receptors (GPCRs). We show here that a novel gene, human rhomboid family-1 (RHBDF1), which was recently reported to have a pivotal role in epithelial cancer cell growth in culture and in xenograft tumors, participates in the modulation of GPCR-mediated EGFR transactivation. The RHBDF1 protein localizes mainly in the endoplasmic reticulum. Silencing the RHBDF1 gene in head and neck squamous cancer cell line 1483 cells with siRNA causes an inhibition of gastrin-releasing peptide (GRP) -induced phosphorylation of EGFR and EGFR-dependent signaling proteins p44/42 MAPK and AKT, accompanied by an inhibition of GRP-induced survival, proliferation, and invasion of the cells. The EGFR signaling pathway itself remains intact, however, as the cells remain responsive to exogenous EGF. In addition, RHBDF1 gene silencing disrupts GRP-stimulated secretion of EGFR ligand TGF-alpha, but not the production of latent TGF-alpha, whereas engineered overexpression of RHBDF1 markedly accelerates the secretion of TGF-alpha. These findings are consistent with the view that RHBDF1 is critically involved in a GPCR ligand-stimulated process leading to the activation of latent EGFR ligands.

Epidermal growth factor receptor structural alterations in gastric cancer

Background

EGFR overexpression has been described in many human tumours including gastric cancer. In NSCLC patients somatic EGFR mutations, within the kinase domain of the protein, as well as gene amplification were associated with a good clinical response to EGFR inhibitors. In gastric tumours data concerning structural alterations of EGFR remains controversial. Given its possible therapeutic relevance, we aimed to determine the frequency and type of structural alterations of the EGFR gene in a series of primary gastric carcinomas.

Methods

Direct sequencing of the kinase domain of the EGFR gene was performed in a series of 77 primary gastric carcinomas. FISH analysis was performed in 30 cases. Association studies between EGFR alterations and the clinical pathological features of the tumours were performed.

Results

Within the 77 primary gastric carcinomas we found two EGFR somatic mutations and several EGFR polymorphisms in exon 20. Six different intronic sequence variants of EGFR were also found. Four gastric carcinomas showed balanced polysomy or EGFR gene amplification. We verified that gastric carcinoma with alterations of EGFR (somatic mutations or copy number variation) showed a significant increase of tumour size (p = 0.0094) in comparison to wild-type EGFR carcinomas.

Conclusion

We demonstrate that EGFR structural alterations are rare in gastric carcinoma, but whenever present, it leads to tumour growth. We considered that searching for EGFR alterations in gastric cancer is likely to be clinically important in order to identify patients susceptible to respond to tyrosine kinase inhibitors.

Molecular correlates of gefitinib responsiveness in human bladder cancer cells

We characterized the effects of the small molecule epidermal growth factor receptor (EGFR) inhibitor gefitinib (ZD1839, Iressa) on cell proliferation in a panel of 17 human bladder cancer cell lines. Gefitinib inhibited DNA synthesis in a concentration-dependent fashion in 6 of 17 lines. Growth inhibition was associated with p27(Kip1) accumulation and decreased cyclin-dependent kinase 2 activity. Gefitinib also inhibited baseline EGFR, AKT, and extracellular signal-regulated kinase (ERK) phosphorylation in the EGFR-dependent cells maintained in serum-free medium, whereas it had no effect on baseline EGFR or ERK phosphorylation in the EGFR-independent cells. Analyses of candidate markers of EGFR dependency revealed that the gefitinib-sensitive cells expressed higher surface EGFR levels than the gefitinib-resistant lines. Gefitinib-sensitive cells generally expressed higher levels of E-cadherin and lower levels of vimentin than the gefitinib-resistant cells, but these correlations were not perfect, suggesting that these markers of epithelial-mesenchymal transition cannot be used by themselves to prospectively predict EGFR-dependent growth. Together, our results show that bladder cancer cells are markedly heterogeneous with respect to their sensitivity to EGFR antagonists. Although surface EGFR levels and epithelial-mesenchymal transition status seem to roughly correlate with responsiveness, they cannot be used by themselves to identify bladder tumors that will be sensitive to EGFR-directed therapy. However, comparing levels of p27(Kip1) or DNA synthesis before and after gefitinib exposure does identify the drug-sensitive cells.

Prognostic value of EGF receptor and tumor cell proliferation in bladder cancer: therapeutic implications

Changes in growth factor receptor expression may confer a growth advantage on tumour cells. Epidermal growth factor-receptor (EGF-R) has been associated with the genesis of bladder tumours. We sought a link between EGF-R expression and MIB-1 cell proliferation and examined their prognostic value in the progression of bladder cancer. Fresh frozen samples from 113 transitional cell carcinomas (TCC) of the bladder and 10 healthy bladders were studied by immunohistochemistry, using monoclonal antibodies for EGF-R expression and MIB-1 for cell proliferation. Qualitative and quantitative immunostaining were analyzed in relation to time to progression and compared with clinical and pathologic parameters for prognostic significance in univariate and multivariate analysis (stepwise logistic regression). EGF-R stained more intensively in invasive tumours. Median nuclear over-expression of MIB-1 was 28%. Progression free survival rate estimates (log rank test) were significantly lower in patients EGF-R positive and with MIB-1 score above 28% (P < 0.0001, P < 0.0001, respectively). Multivariate analysis indicated that MIB-1 immunostaining was the most significant independent variable and EGF-R expression had no additional prognostic value over clinical stage and grade and cell proliferation. The MIB-1 proliferation index is a stronger predictor of bladder tumour progression than is EGF-R over-expression. This marker yield significant prognostic information in addition to stage and grade and may be of value for the clinical management of superficial and invasive bladder carcinomas. The pattern of EGF-R immunostaining and its association with tumour progression makes it a candidate for antigrowth factor therapy.

Downregulation of caveolin-1 function by EGF leads to the loss of E-cadherin, increased transcriptional activity of beta-catenin, and enhanced tumor cell invasion

EGF receptor (EGFR) overexpression correlates with metastasis in a variety of carcinomas, but the underlying mechanisms are poorly understood. We demonstrated that EGF disrupted cell-cell adhesion and caused epithelial-to-mesenchymal transition (EMT) in human tumor cells overexpressing EGFR, and also induced caveolin-dependent endocytosis of E-cadherin, a cell-cell adhesion protein. Chronic EGF treatment resulted in transcriptional downregulation of caveolin-1 and induction of the transcriptional repressor Snail, correlating with downregulation of E-cadherin expression. Caveolin-1 downregulation enhanced beta-catenin-TCF/LEF-1 transcriptional activity in a GSK-3beta-independent manner. Antisense RNA-mediated reduction of caveolin-1 expression in EGFR-overexpressing tumor cells recapitulated these EGF-induced effects and enhanced invasion into collagen gels. We propose that EGF-induced negative regulation of caveolin-1 plays a central role in the complex cellular changes leading to metastasis.

Novel approaches with targeted therapies in bladder cancer. Therapy of bladder cancer by blockade of the epidermal growth factor receptor family

The improved understanding of the molecular biology of urothelial malignancies is helping to define the role of new targets and prognostic indices that can direct the most appropriate choice of treatment for advanced disease. Many human tumors express high levels of growth factors and their receptors that can be used as potential therapeutical targets. Tyrosine-kinase receptors, including many growth factor receptors such the receptors for epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and Her2/neu, have been found overexpressed in urothelial tumors. For many of these growth factor receptors, the degree of expression has been associated with the progression of cancer and a poor prognosis. Among the best studied growth factor receptors are the two members of EGF receptor familiy EGFr (ErbB-1), and Her2/neu (ErbB-2). Several preclinical studies in bladder cancer models, have confirmed that systemic administration of growth factor inhibitors inhibits the growth and metastasis of human transitional cell carcinoma established in the bladder wall of athymic nude mice. Additional studies indicate that therapy with EGFR inhibitors enhances the activity of conventional cytoreductive chemotherapeutic agents, in part by inhibiting tumor cell proliferation, angiogenesis, and inducing apoptosis. Novel targeted therapy hold promise to improve the current results of bladder cancer treatment. Based on the success seen with anti-HER2 monoclonal antibodies (Herceptin) and the promising results with EGFR targeted agents (IMC-C225 Cetuximab, ZD1389 Iressa, OSI-774 Tarceva, GW 57016) in other tumor types, and based on the results obtained in preclinical models, there is a great interest in assessing these agents in patients with bladder cancer. Several trials are now ongoing testing these new agents alone or in combination with chemotherapy in bladder cancer patients. The integration of these newer biologic agents, probably to supplement rather than to supplant chemotherapeutic drugs, should be a primary direction of research with the objective to interfere with multiple aspects of bladder cancer progression. However, the value of integration of biologically targeted agents into combined modality treatment for patients with bladder cancer has still to be proven.

Evidence of high incidence of EGFRvIII expression and coexpression with EGFR in human invasive breast cancer by laser capture microdissection and immunohistochemical analysis

EGFRvIII was first reported in human glioblastomas. Subsequent reports indicated EGFRvIII protein to be frequently detected in several other human cancers, but not in normal tissues. Our previous studies suggested that EGFRvIII could induce a transformation from ligand-dependent non-tumorigenic cell line to ligand-independent malignant phenotype cells in vitro and in vivo. Transfection of EGFRvIII in MCF-7 cell line resulted in a 3-fold increase in colony formation and significantly enhanced tumorigenicity in nude mice (p < 0.001). EGFRvIII could also induce ErbB-2 phosphorylation. The existence and significance of EGFRvIII transcript in human breast cancer, however, was not reported. In our study, we detected the presence of EGFRvIII mRNA and revealed a high incidence (67.8%) of EGFRvIII transcript in human primary invasive breast cancer by utilizing laser capture microdissection (LCM)/RT-PCR to capture pure breast cancer cells. In addition, 57.1% of the infiltrating breast carcinomas expressed both EGFRwt and EGFRvIII mRNA in the same tumor. There is no detectable EGFRvIII mRNA in normal breast tissue. Evaluation of the EGFRwt and EGFRvIII protein levels in the same sample sets by immunohistochemical analysis further confirmed the LCM/RT-PCR finding. Our study provides first direct evidence of high incidence of coexpression of EGFRvIII and EGFRwt in human invasive breast cancer tissue. The unique characteristics and high prevalence of EGFRvIII in invasive human breast cancer as well as negative expression in normal breast may suggest its important role in breast carcinogenesis and make it an ideally potential target for treatment of breast cancer without interrupting normal EGFR signaling.

Epidermal growth factor-induced tumor cell invasion and metastasis initiated by dephosphorylation and downregulation of focal adhesion kinase

Upregulated epidermal growth factor (EGF) receptor (EGFR) expression and EGFR-induced signaling have been correlated with progression to invasion and metastasis in a wide variety of carcinomas, but the mechanism behind this is not well understood. We show here that, in various human carcinoma cells that overexpress EGFR, EGF treatment induced rapid tyrosine dephosphorylation of focal adhesion kinase (FAK) associated with downregulation of its kinase activity. The downregulation of FAK activity was both required and sufficient for EGF-induced refractile morphological changes, detachment of cells from the extracellular matrix, and increased tumor cell motility, invasion, and metastasis. Tumor cells with downregulated FAK activity became less adherent to the extracellular matrix. However, once cells started reattaching, FAK activity was restored by activated integrin signaling. Moreover, this process of readhesion and spreading could not be abrogated by further EGF stimulation. Interruption of transforming growth factor alpha-EGFR autocrine regulation with an EGFR tyrosine kinase inhibitor led to a substantial increase in FAK tyrosine phosphorylation and inhibition of tumor cell invasion in vitro. Consistent with this, FAK tyrosine phosphorylation was reduced in cells from tumors growing in transplanted, athymic, nude mice, which have an intact autocrine regulation of the EGFR. We suggest that the dynamic regulation of FAK activity, initiated by EGF-induced downregulation of FAK leading to cell detachment and increased motility and invasion, followed by integrin-dependent reactivation during readhesion, plays a role in EGF-associated tumor invasion and metastasis.

Role of BMK1 in regulation of growth factor-induced cellular responses

Big mitogen-activated protein kinase (MAPK) 1 (BMK1), also known as ERK5, is a recently identified member of the mammalian MAPK family. Cellular stimulation of BMK1 is induced in response to growth factors, oxidative stress, and hyperosmolar conditions. Specific members of the myocyte enhancer factor 2 family of transcription factors that regulate growth factor-induced early gene expression have been identified as direct downstream targets of BMK1 activity. Recent studies have shown that growth factors of the epidermal growth factor family mediate the sequential activation of a kinase cascade consisting of MAPK kinase kinase 3, MAPK kinase 5, and BMK1. Most importantly, the activation of this signal transduction pathway has been shown to be required for growth factor-mediated cell proliferation and cell-cycle progression. Collectively, these studies establish BMK1 as an important regulator of growth factor-induced cellular responses.

Mutation of cell cycle regulators and their impact on superficial bladder cancer

Early cytogenetic studies in bladder cancer identify regions of chromosomal gain or loss that can be candidate loci for oncogenes and tumor suppressor genes. Oncogenes with potential prognostic significance identified in bladder cancer the RAS family, epidermal growth factor receptor, ERBB-2, MDM2, and cyclin D1. The TP53 gene has been the most thoroughly characterized tumor suppressor gene in bladder cancer, with correlation of TP53 alterations with type of carcinogenic exposure, tumor stage and grade, as well as prognosis. Studies evaluating alterations of the retinoblastoma pathway have identified the retinoblastoma gene, RB, p161NK4A/CDKN2, and E2F-1 as tumor suppressor genes with potential prognostic significance in patients with bladder cancer. Better understanding of the genetic mechanisms underlying bladder tumor development and progression will allow better prevention, diagnosis, and treatment strategies.

Expression of transforming growth factor alpha and epidermal growth factor receptor in human bladder cancer

We analysed the expression of epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-alpha) in human bladder tumours. Tumour biopsies were obtained from 54 patients with primary bladder cancer (18 stage T1 and 36 stage T2-4). The protein and mRNA expression of EGFr and TGF-alpha were quantified by ELISA and competitive RT-PCR, respectively. The EGFr protein level was significantly increased in T2-4 tumours (0.44 x 10(-11); 0.0-27.5 x 10(-11) mol/g) compared with T1 tumours (0.0; 0.0-2.0 x 10(-11) mol/g) (median; range; 2p<0.01). The EGFr protein and mRNA level correlated (Spearman r=0.45, 2p<0.005, n=40). Co-expression of TGF-alpha protein and EGFr protein was significantly associated with muscle invasive tumours (T2-4) (chi-squared=7.9, df=3, p<0.05) and the TGF-alpha protein level correlated significantly with EGFr protein expression (Spearman r=0.56, 2p<0.0001, n=54). While tumour stage correlated with survival, no correlation was observed between survival and the expression of EGFr and/or TGF-alpha. In conclusion, human bladder tumours express both EGFr and TGF-alpha. The expression of EGFr and TGF-alpha are closely correlated, and the expression of EGFr and co-expression of EGFr and TGF-alpha correlate with tumour stage.

Detailed marker chromosome analysis in cell line U-BLC1, established from transitional-cell carcinoma of the bladder

A permanent cell line, U-BLC1, was established from a primary transitional-cell carcinoma, TCC, of the urinary bladder. Karyotype analysis showed the line to be highly aberrant, with a near-triploid chromosome number of 68 to 73. Comparative genomic hybridization revealed some distinct differences between the primary tumor and the established cell line. Karyotype analysis showed 3 marker chromosomes with homogeneously staining regions, HSRs, in the cell line. The HSRs were isolated by microdissection and the microdissection probes were hybridized to normal metaphase chromosomes. The HSRs contain sequences known to be frequently involved in amplification in transitional-cell carcinoma of the bladder, 6p22, 7p11-p12, 9p23-pter, and one region not yet reported to be amplified in primary TCC of the bladder, 1p31-p32. A candidate-gene approach showed that in the region 7p11-p12 the EGFR locus is amplified and highly expressed.

Epidermal growth factor receptor expression: predictive value for the outcome after cystectomy for bladder cancer?

OBJECTIVE

To determine whether epidermal growth factor receptor (EGFR) immunostaining of tumour cells is associated with cancer-specific death after cystectomy for locally advanced bladder cancer.

PATIENTS AND METHODS

The hospital records of all patients treated with cystectomy for urothelial cancer of the urinary bladder between 1967 and 1992 were reviewed retrospectively. The paraffin-embedded specimens obtained before treatment from 173 patients were processed for immunohistochemical staining, using the monoclonal antibody NCL-EGFR (Novocastra, UK). EGFR immunostaining was considered positive if membrane staining was found in at > or = 20% of tumour cells in one or more fields at > or = 200 (area 0.59 mm2).

RESULTS

Most patients (149) received preoperative irradiation and one had neoadjuvant chemotherapy. The mean observation time was 81.3 months; 63 patients (36%) had tumour recurrence within 1-80 months (mean 18.3). Positive EGFR immunostaining was found in 100 patients (58%). The proportion of T2-4 tumours was higher in those EGFR-positive than in those EGFR-negative. Proportional-hazards analysis revealed that clinical stage was significantly associated with cancer-specific death, but EGFR expression was not.

CONCLUSION

Although positive immunostaining for EGFR was more frequent in higher stages of locally advanced bladder cancer, this variable was not an independent predictor of outcome after cystectomy.

Isolation and characterization of a novel bladder cancer cell line: inhibition by epidermal growth factor

A novel continuous cell line, designated BC3c, was established from a surgical biopsy of an invasive solid transitional cell carcinoma of the bladder derived from an 82-yr-old Caucasian female. BC3c cells were near-triploid bearing multiple structural and numerical chromosome anomalies. The epithelial origin of the cancer cells was indicated by the expression of cytokeratins 8 and 19 as well as by the absence of mesenchymal markers. Polymerase chain reaction-restriction-fragment length polymorphisms and single-strand conformation polymorphism mutation detection assays did not reveal any mutations in H-ras codon 12 and K-ras codons 12 and 13. In addition, no mutation in specific hot-spot codons of the p53 gene and no accumulation of the p53 protein were observed. BC3c cells grew rapidly in vitro, even in the absence of exogenous growth factors, because they were found to stimulate their growth in an autocrine manner. BC3c cells were found to express the epidermal growth factor-receptor (EGF-r) abundantly, but in contrast to other established bladder cancer cell lines, human recombinant epidermal growth factor inhibited the cells' proliferation in vitro. These features render the newly established bladder cancer cell line BC3c a useful tool for further experimentation.

Prognostic markers in bladder cancer: a contemporary review of the literature

PURPOSE

We provide a contemporary review of bladder tumor markers and summarize their role as prognostic indicators.

MATERIALS AND METHODS

A comprehensive review of the literature on prognostic markers for transitional cell carcinoma of the bladder was performed.

RESULTS

Intense research efforts are being made to identify and characterize better various bladder cancers and their true biological potential. The need to predict which superficial tumors will recur or progress and which invasive tumors will metastasize has led to the identification of a variety of potential prognostic markers. Blood group antigens, tumor associated antigens, proliferating antigens, oncogenes, peptide growth factors and their receptors, cell adhesion molecules, tumor angiogenesis and angiogenesis inhibitors, and cell cycle regulatory proteins have recently been identified. The potential clinical applications of these tumor markers are under active investigation. Recent attention has focused on which tumor markers may predict the responsiveness of a particular bladder cancer to systemic chemotherapy.

CONCLUSIONS

At present conventional histopathological evaluation of bladder cancer (tumor grade and stage) cannot predict accurately the behavior of most bladder tumors. With a better understanding of the cell cycle, and cell to cell and cell to extracellular matrix interactions as well as improved diagnostic techniques (immunohistochemistry), progress is being made to identify and characterize other potential prognostic markers for transitional cell carcinoma of the bladder. The ultimate goal is to develop reliable prognostic markers that will accurately predict not only the course but also the response of a tumor to therapy. This information may then be used to dictate more aggressive treatment for tumors that are likely to progress and less aggressive treatment for those that are unlikely to progress. In the future these biological markers may also be used in gene therapy for the treatment of bladder cancer.

Recent aspects in the diagnosis and prognosis of bladder cancer

Epidemiologic studies have stated the progressive increase of bladder tumors during the last decades. The aim of our review is to refer to factors implicated in bladder carcinogenesis (such as activated oncogenes, growth factors and chromosomal aberrations) and to resistance to drug uptake (i.e., multidrug resistance gene and P-glycoprotein). The review also provides information of diagnostic and prognostic significance, based on DNA analysis of transitional cancer cells. In addition to cytometric data, alternative counterings for estimation of the S-phase fraction, useful in indicating the biologic behavior of bladder cancer, are presented. Knowledge of such mechanisms results in a better approach to the diagnosis, prognosis and prevention of bladder carcinomas, especially those that do not respond to systemic intravesical chemotherapy. We have tried to mention all significant factors related to the development of bladder cancer. We conclude that the progress made in understanding the pathogenesis of bladder cancer has been significant. However, more studies are needed in order to introduce and adopt reliable criteria to accurately predict the clinical behavior.

Expression of epidermal growth factor receptor in urinary bladder cancer metastases

Bladder cancers frequently exhibit an increased number of epidermal growth factor receptors (EGFR) in comparison to normal urothelium. The EGFR could potentially be a target for toxic conjugates. The aim of our study was to compare the expression of EGFR in metastases with concurrent or primary tumour in the urinary bladder using immunohistochemical techniques and a monoclonal antibody. Tumour material from 20 patients was investigated. The majority (13/20) of the metastases were homogeneously stained and showed a moderate to strong membranous staining for EGFR. The expression of EGFR in primary bladder tumours and metastases was similar. There was no indication that tumour tissue exposed to chemotherapy or radiation had a decreased number of EGFR. Targeting of the EGFR thus seems potentially applicable to metastatic disease.

The role of p53, MDM2 and c-erb B-2 oncoproteins, epidermal growth factor receptor and proliferation markers in the prognosis of urinary bladder cancer

The immunohistological expression of p53 and MDM2 oncoproteins was examined in paraffin embedded tissue from 106 patients with transitional cell carcinoma of the urinary bladder and was related to various clinicopathological features, the expression of proliferation associated markers (proliferating cell nuclear antigen - PCNA - and Ki-67), c-erb B-2 oncoprotein and epidermal growth factor receptor (EGFR), as well as to survival. MDM2 immunoreactivity was seen in 38% of our cases, and in 14% was accompanied by p53 positive immunohistochemistry. The rate of p53 positivity was associated with grade, stage and papillary status, whereas MDM2 immunopositivity increased with grade and stage (Ta VS T1), and MDM2 labeling index (LI) with stage. MDM2 expression was related to p53 expression and less strongly to proliferation rate (Ki-67 LI). The simultaneous p53 and MDM2 expression was more frequently observed in higher grade and stage tumours. C-erb B-2, EGFR and proliferation marker expression increased with grade, stage and non-papillary configuration. In univariate analysis high grade, solid growth pattern, advanced T-category, cystectomy, EGFR and Ki-67 expression were linked to shorter overall survival but only Ki-67 LI, along with T-category and type of therapy, had independent prognostic value. C-erb B-2 expression and stage were the two independent predictors of disease-free survival and Ki-67 LI and EGFR LI the independent predictors of post-relapse survival. For patients with superficial tumors PCNA LI emerged as the single independent determinator of survival. p53 and MDM2 expression did not appear to have any significant impact on survival, although the simultaneous expression of p53 and MDM2 turned out to be a highly significant parameter of shortened overall survival in univariate analysis.

Impact of the expression of epidermal growth factor, transforming growth factor alpha, and epidermal growth factor receptor on the prognosis of superficial bladder cancer

OBJECTIVES

To investigate the correlation of epidermal growth factor receptor (EGFR) expression and its ligands EGF and transforming growth factor-alpha (TGF-alpha) with disease outcome in a cohort of patients with superficial bladder cancer.

METHODS

Tumor samples of 21 patients with transitional cell carcinoma of the bladder were analyzed by immunohistochemistry for expression of EGFR, EGF, and TGF-alpha. Disease-related events were recorded during a routine clinical follow-up and analyzed for possible correlation with the expression status of the above-mentioned proteins.

RESULTS

All Stage pT1 transitional cell carcinomas expressed EGFR, and 10 of 21 (48%) tumors showed focal areas of strong EGF and/or TGF-alpha expression. Of these, 80% with EGF positivity (8 of 10) had recurrences, whereas only 9% of patients without EGF staining (1 of 11) did so. The same pattern was observed with TGF-alpha. A strong association was confirmed between EGF/TGF-alpha positivity and tumor recurrence (P <0.005). We also found that EGF and TGF-alpha were expressed in stroma and/or around the vessels of tumor tissue in 48% and 38% of the tumors, respectively. No association was found between the recurrence rate/vascular invasion and the stromal/vascular wall expression of the growth factors.

CONCLUSIONS

Expression of EGF and TGF-alpha is correlated with tumor recurrence. Also, there is the ability of vessel walls to express EGF and TGF-alpha in superficial bladder cancer. Further clarification of the impact of this expression on angioinvasion of tumor cells may be helpful in understanding the nature of local invasion and metastasis.

Invasion of the bladder by transitional cell carcinoma: its relation to histologic grade and expression of p53, MIB-1, c-erb B-2, epidermal growth factor receptor, and bcl-2

BACKGROUND

Although pathologic level of invasion and histologic grade are helpful in predicting the clinical outcome of transitional cell carcinoma of the bladder, they also create uncertainty. Immunohistochemical staining for p53, MIB-1, epidermal growth factor receptor (EGFR), c-erb B-2, and bcl-2 have shown promise as prognostic factors when evaluated singly, although multivariate analyses that include histologic grade and the interactive effects of these markers have not been studied extensively. The authors have initiated a prospective study to determine whether these markers add prognostic information to that provided by level of invasion and histologic grade. This initial report details how these five markers relate to invasion of the bladder after controlling for the effects of histologic grade.

METHODS

The authors evaluated 229 transitional cell carcinomas in 229 patients using the World Health Organization grading schema and immunohistochemical staining with antigen retrieval for p53, MIB-1, EGFR, c-erb B-2, and bcl-2, and they related these markers to invasion after controlling for grade with a multivariate logistic regression model.

RESULTS

Although Grades 2 and 3 were the most important for predicting invasion, Grade 2 tumors that stained for either MIB-1 or p53 indicated a significantly greater probability of invasion than suggested by grade alone. bcl-2 and p53 had an opposing and interactive effect: when p53 was absent, the presence of bcl-2 implied less probability of invasion; but when both bcl-2 and p53 were present, the protective effect of bcl-2 was no longer observed. Although neither EGFR nor c-erb B-2 were as important as the other three markers in determining the risk of invasion, Grade 3 tumors that stained for one, and especially both, of these markers were less likely to be invasive.

CONCLUSIONS

These five markers sort into three interactive pairs: MIB-1 and p53, bcl-2 and p53, and EGFR and c-erb B-2. MIB-1 and p53 together imply a greater probability of invasion. bcl-2 appears to have a dual role, which depends on the presence of accumulated p53. Finally, EGFR and c-erb B-2 related closely to each other and in Grade 3 tumors imply a lesser probability of invasion. It is likely that combinations of markers, or correlations between markers and grades, will yield prognostic information that is more powerful than what histologic grade alone can provide.

Mitosis-specific negative regulation of epidermal growth factor receptor, triggered by a decrease in ligand binding and dimerization, can be overcome by overexpression of receptor

The function of epidermal growth factor receptor (EGFR) was found to be negatively regulated in M phase in which it showed less phosphotyrosine content and reduced intrinsic kinase activity accompanied by retarded electrophoretic mobility owing to total hyperphosphorylation. Ligand-induced autophosphorylation and downstream signaling of EGFR were tightly suppressed in M phase due to a decrease in ligand binding affinity and the inability of epidermal growth factor (EGF) to induce receptor dimerization. There was no change in the number of surface-exposed EGF receptors between G0/G1 and M phases of the cell cycle. Hyperphosphorylation (due to serine and/or threonine phosphorylation) correlates with the unresponsiveness of cells to EGF-mediated stimulation of tyrosine phosphorylation in cells that express the normal or basal level of EGFR. This M phase-specific negative regulation was overcome by overexpression of EGFR, which was responsive to ligand throughout the cell cycle and revealed ligand-induced signaling in the M phase. These findings indicate that EGFR does not respond to ligand stimulation in M phase and suggest that a negative regulation of ligand-receptor interactions in M phase may control the normal function of receptor tyrosine kinase and that receptor overexpression will disrupt this cell cycle-dependent regulation of receptor tyrosine kinases.

Clinical relevance of transforming growth factor-beta 1 in the urine of patients with hepatocellular carcinoma

To assess the clinical relevance of transforming growth factor-beta 1 (TGF-beta 1) in the urine of patients with hepatocellular carcinoma (HCC), TGF-beta 1 was measured, by radioimmunoassay, in 140 patients with HCC, 50 cirrhotic patients, 30 patients with chronic active hepatitis, and 50 healthy controls. The results indicate that there were significantly increased urinary TGF-beta 1 levels in patients with HCC. Raised TGF-beta 1 levels were associated, in a dose-related fashion, with increased risk for development of HCC (odds ratio, 1.05, 95% confidence interval, 1.03-1.07). HCC patients with raised TGF-beta 1 levels had shorter survival than those with normal TGF-beta 1 levels (p = 0.038). TGF-beta 1 levels decreased after successful anticancer therapy (p < 0.0001). There was an inverse correlation between TGF-beta 1 and serum alpha-fetoprotein (AFP) (r = -0.199, p < 0.04). Receiver operating characteristics (ROC) curve analysis indicated that parallel determination of TGF-beta 1 and AFP significantly increased the sensitivity and diagnostic accuracy, with a high specificity. In conclusion, raised urinary TGF-beta 1 was associated with HCC development. It is a predictor of poor prognosis, and a tumor marker for diagnosis and therapeutic follow-up of HCC.

c-myc, c-erbB-1 and c-erbB-2 expressions in urothelial carcinoma

The expression of c-myc, c-erbB-1 and c-erbB-2 in 24 cases of urothelial carcinoma by Southern and northern blot analysis, and immunohistochemistry was examined. The results were compared with the pathological grade and stage. We found elevated mRNA expressions of c-myc and c-erbB-1 in 19 and 11 of 21 cases, respectively, but there was no apparent amplification or rearrangement of these oncogenes in any of the cases examined. By immunohistochemistry using anti-epidermal growth factor receptor antibody, most of the cases showed positive immunoreactivity on the cancer cell membranes, and cancers of higher pathological grade and stage showed more intense staining. By contrast, amplification of c-erbB-2 was detected in four of 24 cases, all of which were assigned to a high pathological grade (G3). Elevated c-erbB-2 mRNA levels appeared to correlate with the pathological grade of the cancers. Positive immunohistochemical reactions to c-erbB-2 were found in the cancer cell membranes in three of 24 cases, which were accompanied by amplification and elevated mRNA levels of c-erbB-2. In conclusion, expressions of c-myc, c-erbB-1 and c-erbB-2 were all elevated in the majority of urothelial carcinomas, but the amplification was not universal.

Cochliobolic acid, a novel metabolite produced by Cochliobolus lunatus, inhibits binding of TGF-alpha to the EGF receptor in a SPA assay

Cochliobolic acid (1), a novel biologically active natural product, is produced by submerged fermentation of Cochliobolus lunatus. Compound 1 was determined to be a novel polyketide possessing a substituted tetrahydrofuran ring, a conjugated polyene chain and a 1,2-diketone moiety, by interpretation of NMR, MS, and UV/vis spectroscopic data. Compound 1 inhibits the binding of TGF-alpha to the EGF receptor of the human epidermal cell line A431 in a SPA assay with an IC50 of 1.6 microM.

Expression of the type 1 tyrosine kinase growth factor receptors EGF receptor, c-erbB2 and c-erbB3 in bladder cancer

Expression of the c-erbB3 protein was determined in transitional cell carcinoma of the bladder by immunohistochemistry. Strong membrane staining was observed in 10 per cent of cases (7/70) and cytoplasmic and membrane overexpression in 20 per cent (14/70). Overexpression of the epidermal growth factor (EGF) receptor (36 per cent, 25/70) and c-erbB2 proteins (9 per cent 6/70) was determined in the same series of cases. c-erbB3 overexpression was positively correlated with EGF receptor expression (P < 0.025) but appeared to be inversely associated with c-erbB2 overexpression.

Application of competition theory to tumour growth: implications for tumour biology and treatment

To assess critical parameters controlling tumour growth and response to therapy, competition theory models the tumour-host interface as a network of interacting normal and malignant cell populations using coupled, non-linear differential equations. When the equations are analysed under conditions which simulate tumour development, three phases of tumour growth, each with different critical parameters, can be predicted. Transitions between these phases correspond to the initiation, promotion and invasion stages demonstrated in experimental models of carcinogenesis. Critical cellular properties for each transition are predicted including phenomena already demonstrated experimentally such as the linkage of invasive tumour growth with acquisition of angiogenesis. The model also predicts the previously unknown phenomenon of "functional equivalence" in which disparate tumour traits can play identical roles in tumour growth and invasion. This approach allows the diverse but inconsistent properties of transformed cells to be understood according to their specific contribution to tumorigenesis. The models have significant implications for treatment strategies.

Transforming growth factor alpha and epidermal growth factor levels in bladder cancer and their relationship to epidermal growth factor receptor

We have examined levels of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) in neoplastic and non-neoplastic bladder tissue using a standard radioimmunoassay technique. Tumour samples had much higher TGF-alpha levels compared with EGF and TGF-alpha levels in malignant tissue were significantly higher than in benign bladder samples. There was, in addition, a difference in mean EGF levels from 'normal' bladder samples from non-tumour bearing areas of bladder in patients with bladder cancer compared with 'normal' bladder tissue obtained at the time of organ retrieval surgery. Levels of EGF and TGF-alpha did not correlate with levels of EGF receptor (EGFR) as determined by a radioligand binding method but levels of TGF-alpha > 10 ng gm-1 of tumour tissue did correlate with EGFR positivity defined using immunohistochemistry. These data suggest that TGF-alpha is the likely ligand for EGFR in bladder tumours.

C-erbB-2 in bladder cancer: molecular biology, correlation with epidermal growth factor receptors and prognostic value

PURPOSE

To study the c-erbB-2 oncogene in primary transitional cell bladder cancer.

MATERIALS AND METHODS

Ninety-five patients with known clinical follow-up and epidermal growth factor receptor (EGFr) status were studied for expression of c-erbB-2 by immunostaining. Possible mechanisms underlying increased staining for c-erbB-2 protein were investigated by analyzing DNA and RNA encoding c-erbB-2.

RESULTS

Strong positive staining for c-erbB-2 was detected in 20 (21%) tumors, with weaker staining in a further 13 (14%). There was no correlation between increased staining for c-erbB-2 and tumor stage, grade, or EGFr status. There was a low rate of amplification of the c-erbB-2 gene (1 of 24) on Southern blotting with a higher rate of elevated c-erbB-2 mRNA (4 of 44) with dot blot hybridization. For pT1 tumors, the rate of recurrence was higher for those tumors which were positive for c-erbB-2.

CONCLUSIONS

c-erbB-2 oncoprotein is expressed by a significant proportion of transitional cell tumors of the bladder. In this study, the prognostic significance of c-erbB-2 expression appears limited.

Evaluation of overexpression of p53 tumor suppressor protein in superficial and invasive transitional cell bladder cancer: comparison with DNA ploidy

OBJECTIVES

p53 tumor suppressor gene is considered to play a significant role in carcinogenesis. Mutations in the p53 are the most frequent genetic abnormalities encountered in human malignancies. Our aim was to investigate the expression of p53 oncoprotein in superficial and invasive transitional cell bladder cancer (TCC) as well as its correlation with established prognostic factors, such as histologic grade, tumor stage, DNA content, and survival.

METHODS

Forty-five patients with superficial TCC (Ta-T1) and 42 with invasive TCC (T2-T4) were included in our study. Material from transurethral biopsy was examined using an immunohistochemical method and the monoclonal antibody Pab 1801.

RESULTS

p53 tumor suppressor protein was overexpressed in 48.3% of TCC cases and more frequently in invasive than superficial TCCs (P = 0.03) and undetectable in the tumor adjacent to normal tissue. p53 positivity was related to the degree of differentiation and with the stage of the disease of invasive TCCs (P = 0.03 and P = 0.004, respectively), whereas no statistical significance was documented for superficial TCCs. Moreover, p53 overexpression demonstrated a statistical significance with DNA ploidy in superficial Ta-T1 tumors (P = 0.04) and was suggestive in invasive T2-T4 tumors (P = 0.08). There was no correlation of recurrence related to p53-positive superficial tumors (P = 0.29). Patients with p53-positive invasive TCCs showed statistically significant worse survival (P = 0.007), but in multivariate analysis, p53 positivity is not independently related to poor overall survival (P = 0.30). When we combined ploidy and p53 status, we realized that the subset of patients with aneuploidy and p53 positivity had the worst prognosis (P = 0.008).

CONCLUSIONS

The results suggest the involvement of p53 protein as a late event in bladder carcinogenesis. p53 does not seem to be a prognostic marker for recurrences of superficial tumors and is not independently related to survival. The aneuploidy of tumors correlates with the p53 positivity in bladder cancer. The combined expression of aneuploidy and p53 positivity in invasive tumors has strong association with the survival of patients.