Matrix metalloproteinase-1 is induced by epidermal growth factor in human bladder tumour cell lines and is detectable in urine of patients with bladder tumours

Temozolomide alleviates breast carcinoma via the inhibition of EGFR/ERK/ MMP-1 pathway with induction of apoptotic events

PURPOSE

To evaluate the chemotherapeutic activity of temozolomide counter to mammary carcinoma.

METHODS

In-vitro anticancer activity has been conducted on MCF7 cells, and mammary carcinoma has been induced in Wistar rats by introduction of 7, 12-Dimethylbenz(a)anthracene (DMBA), which was sustained for 24 weeks. Histopathology, immunohistochemistry, cell proliferation study and apoptosis assay via TUNEL method was conducted to evaluate an antineoplastic activity of temozolomide in rat breast tissue.

RESULTS

IC50 value of temozolomide in MCF7 cell has been obtained as 103 μM, which demonstrated an initiation of apoptosis. The temozolomide treatment facilitated cell cycle arrest in G2/M and S phase dose dependently. The treatment with temozolomide suggested decrease of the hyperplastic abrasions and renovation of the typical histological features of mammary tissue. Moreover, temozolomide therapy caused the downregulation of epidermal growth factor receptor, extracellular signal-regulated kinase, and metalloproteinase-1 expression and upstream of p53 and caspase-3 proliferation to indicate an initiation of apoptotic events.

CONCLUSIONS

The occurrence of mammary carcinoma has been significantly decreased by activation of apoptotic pathway and abrogation of cellular propagation that allowable for developing a suitable mechanistic pathway of temozolomide in order to facilitate chemotherapeutic approach.

Comprehensive proteomics and platform validation of urinary biomarkers for bladder cancer diagnosis and staging

BACKGROUND

Bladder cancer (BC) is among the most common cancers diagnosed in men in the USA. The current gold standards for the diagnosis of BC are invasive or lack the sensitivity to correctly identify the disease.

METHODS

An aptamer-based screen analyzed the expression of 1317 proteins in BC compared to urology clinic controls. The top hits were subjected to systems biology analyses. Next, 30 urine proteins were ELISA-validated in an independent cohort of 68 subjects. Three of these proteins were next validated in an independent BC cohort of differing ethnicity.

RESULTS

Systems biology analysis implicated molecular functions related to the extracellular matrix, collagen, integrin, heparin, and transmembrane tyrosine kinase signaling in BC susceptibility, with HNF4A and NFKB1 emerging as key molecular regulators. STEM analysis of the dysregulated pathways implicated a functional role for the immune system, complement, and interleukins in BC disease progression. Of 21 urine proteins that discriminated BC from urology clinic controls (UC), urine D-dimer displayed the highest accuracy (0.96) and sensitivity of 97%. Furthermore, 8 urine proteins significantly discriminated MIBC from NMIBC (AUC = 0.75-0.99), with IL-8 and IgA being the best performers. Urine IgA and fibronectin exhibited the highest specificity of 80% at fixed sensitivity for identifying advanced BC.

CONCLUSIONS

Given the high sensitivity (97%) of urine D-dimer for BC, it may have a role in the initial diagnosis or detection of cancer recurrence. On the other hand, urine IL-8 and IgA may have the potential in identifying disease progression during patient follow-up. The use of these biomarkers for initial triage could have a significant impact as the current cystoscopy-based diagnostic and surveillance approach is costly and invasive when compared to a simple urine test.

Expression of epidermal growth factor receptor and human epidermal growth factor receptor 2 in urothelial bladder carcinoma in an Egyptian cohort: Clinical implication and prognostic significance

BACKGROUND

Bladder cancer (BC) has a particular importance in Egyptian patients due to aggressive behavior and absence of prognostic markers.

OBJECTIVE

To evaluate the expression of gene and protein expression of HER2 and epidermal growth factor (EGFR) in Egyptian patients with BC and ultimately to investigate their clinical implication and prognostic significance.

MATERIAL AND METHODS

The study was carried out on 46 patients with urothelial bladder BC. Tissue were obtained from transurethral resection (N = 22) and radical cystectomy (N = 24) specimens. The original hematoxylin and eosin slides were re-evaluated and the formalin fixed, paraffin-embedded (FFPE) tissues which had sufficient tumor tissue (>75%) and minimal or absent tumor necrosis were selected for immunohistochemistry (IHC) and RNA extraction. Furthermore, five control biopsies were obtained from patients with cystitis. Follow-up data were retrieved from the medical records which included the treatment regimen, disease recurrence and/or progression, and survival.

RESULTS

EGFR and HER2 protein were overexpressed in 35% and 46% of patients respectively. EGFR was correlated with the tumor size, grade and pathological stage, with a similar trend for HER2. The recurrence rate was higher in patients with expression of any of the markers. Gene expression was significantly higher (10.6-folds) for EGFR and (21-folds) for HER2 in patients with BC in comparison to control patients. Survival analysis showed lower median disease-free survival in association with HER2 protein overexpression.

CONCLUSIONS

Our data highlighted the prognostic significance of EGFR and HER in BC and proposed their possible use as predictive markers and potential therapeutic targets.

Association of Matrix Metalloproteinase-1 Genotypes With Bladder Cancer Risk

AIM

There is very little literature reporting the association of matrix metalloproteinase-1 (MMP1) with personal susceptibility to bladder cancer. In the current study, we carried out the first examination of the contribution of MMP1 rs1799750 to bladder cancer risk in Taiwanese.

MATERIALS AND METHODS

A total of 375 bladder cancer cases and 375 healthy controls were genotyped for MMP1 rs1799750 via polymerase chain reaction-restriction fragment length polymorphism methodology and this was evaluated for association with clinicopathological factors.

RESULTS

The frequencies of MMP1 rs1799750 2G/2G, 1G/2G, and 1G/1G genotypes were 35.7%, 44.8% and 19.5% in the group with bladder cancer and 32.5%, 46.4%, and 21.1% in the healthy control group (p for trend=0.6362). The odds ratios (ORs) for bladder cancer risk after adjusting for age and gender for those carrying 1G/2G and 1G/1G genotypes at MMP1 rs1799750 were 0.88 (95% CI=0.62-1.24, p=0.4357) and 0.83 (95% CI=0.61-1.26, p=0.3990), respectively, compared with the wild-type 2G/2G genotype. In allelic frequency analysis, the adjusted OR for those carrying the 1G allele at MMP1 rs1799750 was 0.87 (95% CI=0.71-1.23, p=0.3479) compared to those people carrying a 2G allele.

CONCLUSION

Our findings indicated that the genotypes at MMP1 rs1799750 appear to play little role in determining personal susceptibility to bladder cancer for Taiwanese.

Prognostic significance of epidermal growth factor receptor (EGFR) over expression in urothelial carcinoma of urinary bladder

Background

Epidermal growth factor receptor (EGFR) has been shown to have abnormal expression in many human cancers and is considered as a marker of poor prognosis. Frequency of over expression in bladder cancer has not been studied in our population; therefore we aimed to evaluate the frequency and prognostic significance of EGFR immunohistochemical expression in locoregional population.

Methods

We performed EGFR immunohistochemistry on 126 cases of bladder cancer and association of EGFR expression with tumor grade, lamina propria invasion, deep muscle invasion and recurrence of disease was evaluated.

Results

High EGFR expression was noted in 26.2% (33 cases), 15.1% (19 cases) and 58.7% (74 cases) revealed low and no EGFR expression respectively. Significant association of EGFR expression was noted with tumor grade, lamina propria invasion, deep muscle invasion and recurrence status while no significant association was seen with age, gender and overall survival. Kaplan- Meier curves revealed significant association of EGFR expression with recurrence while no significant association was seen with overall survival.

Conclusion

Significant association of EGFR overexpression with tumor grade, muscularis propria invasion and recurrence signifies its prognostic value; therefore EGFR can be used as a prognostic biomarker in Urothelial bladder carcinoma.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.

Bladder carcinoma data with clinical risk factors and molecular markers: a cluster analysis

Bladder cancer occurs in the epithelial lining of the urinary bladder and is amongst the most common types of cancer in humans, killing thousands of people a year. This paper is based on the hypothesis that the use of clinical and histopathological data together with information about the concentration of various molecular markers in patients is useful for the prediction of outcomes and the design of treatments of nonmuscle invasive bladder carcinoma (NMIBC). A population of 45 patients with a new diagnosis of NMIBC was selected. Patients with benign prostatic hyperplasia (BPH), muscle invasive bladder carcinoma (MIBC), carcinoma in situ (CIS), and NMIBC recurrent tumors were not included due to their different clinical behavior. Clinical history was obtained by means of anamnesis and physical examination, and preoperative imaging and urine cytology were carried out for all patients. Then, patients underwent conventional transurethral resection (TURBT) and some proteomic analyses quantified the biomarkers (p53, neu, and EGFR). A postoperative follow-up was performed to detect relapse and progression. Clusterings were performed to find groups with clinical, molecular markers, histopathological prognostic factors, and statistics about recurrence, progression, and overall survival of patients with NMIBC. Four groups were found according to tumor sizes, risk of relapse or progression, and biological behavior. Outlier patients were also detected and categorized according to their clinical characters and biological behavior.

Epidermal growth factor receptor expression in canine transitional cell carcinoma

Transitional cell carcinoma (TCC), a urinary bladder tumor with high mortality, is encountered commonly in dogs. Whereas overexpression of epidermal growth factor receptor (EGFR) is associated with development of human urinary bladder cancer, information on EGFR expression in canine TCC is lacking. In this study, EGFR protein and mRNA expression in canine normal bladder (n=5), polypoid cystitis (n=5) and TCC (n=25) were examined by immunohistochemistry and real-time polymerase chain reaction. EGFR protein expression was significantly higher in TCC than that in normal healthy bladder (P<0.001) and polypoid cystitis (P<0.005). High EGFR protein expression was significantly (P<0.01) associated with TCC with a sensitivity of 72% and specificity of 100%. Comparative analysis of protein and mRNA expression levels in TCC showed significant positive correlation (r=0.88, P<0.05) between mRNA and protein expression. These findings suggest that intense expression of EGFR protein could be used as a marker to help canine TCC diagnosis.

Bladder carcinoma: understanding advanced and metastatic disease with potential molecular therapeutic targets

This article is an expert review of bladder cancer genetics focusing on genetic changes and their significance in the pathogenesis and progression of bladder transitional cell carcinoma, in particular, muscle-invasive disease. Alongside the relevant genetic markers and their products, new therapeutic targets and agents that are being developed are presented.

Transcriptional Modulation of the ERK1/2 MAPK and NF-κB Pathways in Human Urothelial Cells After Trivalent Arsenical Exposure: Implications for Urinary Bladder Cancer

Chronic exposure to drinking water contaminated with inorganic arsenic (iAs) is associated with an increased risk of urinary bladder (UB) cancers in humans. The exact role of specific iAs metabolite(s) in As-mediated carcinogenesis remains largely unknown. Experimental evidence suggests that trivalent arsenicals, namely arsenite (iAsIII) and two of its metabolites, monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII), are possible proximate UB carcinogens. Here, we used a transcriptomics approach to examine perturbed molecular pathways in a human urothelial cell line (UROtsa) after short-term exposure to iAsIII, MMAIII and DMAIII. Molecular pathways containing genes that encode proteins implicated in UB cancer development were perturbed by both MMAIII and DMAIII. These pathways included those of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase (ERK 1/2 MAPK) and nuclear factor kappa beta (NF-κB). Together, these results may inform the current understanding of effects in the UB induced by acute As exposure and the relationship of these effects with As-mediated carcinogenesis.

Matrix Metalloproteinases and Bladder Cancer: What is New?

Urothelial bladder cancer represents a heterogeneous disease with divergent pathways of tumorigenesis. Tumor invasion and progression are a multifactorial process promoted by microenvironmental changes that include overexpression of matrix metalloproteinases (MMPs). Recent data clearly challenge the classic dogma that MMPs promote metastasis only by modulating the remodeling of extracellular matrix. Indeed, MMPs have also been attributed as an impact on tumor cell behavior in vivo as a consequence of their ability to cleave growth factors, cell surface receptors, cell adhesion molecules, and chemokines/cytokines. Levels of the different MMPs can be measured in several sample types, including tissue, blood (serum and plasma), and urine, and using different methodologies, such as immunohistochemistry, real-time PCR, western and northern blot analyses, enzyme-linked immunosorbent assay, and zymography. Several MMPs have been identified as having potential diagnostic or prognostic utility, whether alone or in combination with cytology. Although MMP inhibitors have shown limited efficacy, advances in the understanding of the complex physiologic and pathologic roles of MMPs might permit the development of new MMP-specific and tumor-specific therapies. In this paper we update the understanding of MMPs based on a systematic PubMed search encompassing papers published up to December 2011.

Desmocollin 2 is a new immunohistochemical marker indicative of squamous differentiation in urothelial carcinoma

AIMS

Urothelial carcinoma (UC) with squamous differentiation tends to present at higher stages than pure UC. To distinguish UC with squamous differentiation from pure UC, a sensitive and specific marker is needed. Desmocollin 2 (DSC2) is a protein localized in desmosomal junctions of stratified epithelium, but little is known about its biological significance in bladder cancer. We examined the utility of DSC2 as a diagnostic marker.

METHODS AND RESULTS

We analysed the immunohistochemical characteristics of DSC2, and studied the relationship of DSC2 expression with the expression of the known markers uroplakin III (UPIII), cytokeratin (CK)7, CK20, epidermal growth factor receptor (EGFR), and p53. DSC2 staining was detected in 24 of 25 (96%) cases of UC with squamous differentiation, but in none of 85 (0%) cases of pure UC. DSC2 staining was detected only in areas of squamous differentiation. DSC2 expression was mutually exclusive of UPIII expression, and was correlated with EGFR expression. Furthermore, DSC2 expression was correlated with higher stage (P = 0.0314) and poor prognosis (P = 0.0477).

CONCLUSIONS

DSC2 staining offers high sensitivity (96%) and high specificity (100%) for the detection of squamous differentiation in UC. DSC2 is a useful immunohistochemical marker for separation of UC with squamous differentiation from pure UC.

Guanylate binding protein 1 is a novel effector of EGFR-driven invasion in glioblastoma

Although GBP1 (guanylate binding protein 1) was among the first interferon-inducible proteins identified, its function is still largely unknown. Epidermal growth factor receptor (EGFR) activation by amplification or mutation is one of the most frequent genetic lesions in a variety of human tumors. These include glioblastoma multiforme (GBM), which is characterized by independent but interrelated features of extensive invasion into normal brain parenchyma, rapid growth, necrosis, and angiogenesis. In this study, we show that EGFR activation promoted GBP1 expression in GBM cell lines through a signaling pathway involving Src and p38 mitogen-activated protein kinase. Moreover, we identified YY1 (Yin Yang 1) as the downstream transcriptional regulator regulating EGFR-driven GBP1 expression. GBP1 was required for EGFR-mediated MMP1 (matrix metalloproteinase 1) expression and glioma cell invasion in vitro. Although deregulation of GBP1 expression did not affect glioma cell proliferation, overexpression of GBP1 enhanced glioma cell invasion through MMP1 induction, which required its C-terminal helical domain and was independent of its GTPase activity. Reducing GBP1 levels by RNA interference in invasive GBM cells also markedly inhibited their ability to infiltrate the brain parenchyma of mice. GBP1 expression was high and positively correlated with EGFR expression in human GBM tumors and cell lines, particularly those of the neural subtype. Together, these findings establish GBP1 as a previously unknown link between EGFR activity and MMP1 expression and nominate it as a novel potential therapeutic target for inhibiting GBM invasion.

A framework to select clinically relevant cancer cell lines for investigation by establishing their molecular similarity with primary human cancers

Experimental work on human cancer cell lines often does not translate to the clinic. We posit that this is because some cells undergo changes in vitro that no longer make them representative of human tumors. Here, we describe a novel alignment method named Spearman's rank correlation classification method (SRCCM) that measures similarity between cancer cell lines and human tumors via gene expression profiles, for the purpose of selecting lines that are biologically relevant. To show utility, we used SRCCM to assess similarity of 36 bladder cancer lines with 10 epithelial human tumor types (N = 1,630 samples) and with bladder tumors of different stages and grades (N = 144 samples). Although 34 of 36 lines aligned to bladder tumors rather than other histologies, only 16 of 28 had SRCCM assigned grades identical to that of their original source tumors. To evaluate the clinical relevance of this approach, we show that gene expression profiles of aligned cell lines stratify survival in an independent cohort of 87 bladder patients (HR = 3.41, log-rank P = 0.0077) whereas unaligned cell lines using original tumor grades did not. We repeated this process on 22 colorectal cell lines and found that gene expression profiles of 17 lines aligning to colorectal tumors and selected based on their similarity with 55 human tumors stratified survival in an independent cohort of 177 colorectal cancer patients (HR = 2.35, log-rank P = 0.0019). By selecting cell lines that reflect human tumors, our technique promises to improve the clinical translation of laboratory investigations in cancer.

Pathobiology and chemoprevention of bladder cancer

Our understanding of the pathogenesis of bladder cancer has improved considerably over the past decade. Translating these novel pathobiological discoveries into therapies, prevention, or strategies to manage patients who are suspected to have or who have been diagnosed with bladder cancer is the ultimate goal. In particular, the chemoprevention of bladder cancer development is important, since urothelial cancer frequently recurs, even if the primary cancer is completely removed. The numerous alterations of both oncogenes and tumor suppressor genes that have been implicated in bladder carcinogenesis represent novel targets for therapy and prevention. In addition, knowledge about these genetic alterations will help provide a better understanding of the biological significance of preneoplastic lesions of bladder cancer. Animal models for investigating bladder cancer development and prevention can also be developed based on these alterations. This paper summarizes the results of recent preclinical and clinical chemoprevention studies and discusses screening for bladder cancer.

Matrix metalloproteinases and their clinical relevance in urinary bladder cancer

Matrix metalloproteinases (MMPs) have important roles in several cancer-supporting cellular processes, such as extracellular matrix (ECM) remodeling, angiogenesis, apoptosis, epithelial-to-mesenchymal transition and cell proliferation. This broad range of activity has led to considerable interest in the use of MMPs in the clinical setting as diagnostic or prognostic biomarkers and as therapeutic targets. Levels of the different MMPs can be measured in several sample types, including paraffin-embedded or fresh frozen tissue, serum, plasma and urine, and by various analytical methodologies, such as immunohistochemistry, real-time PCR, western and northern blot analyses, enzyme-linked immunosorbent assay and zymography. Several MMPs have been identified as having potential diagnostic or prognostic utility, whether alone or in combination with currently available diagnostic tests or imaging modalities. Although the early broad-spectrum anti-MMP agents showed a lack of efficacy, our continually improving understanding of the complex physiologic and pathologic roles of MMPs might enable the development of new MMP-specific and tumor-specific therapies. Accordingly, MMPs will continue to be the subjects of intensive research in bladder cancer.

CCL25 mediates migration, invasion and matrix metalloproteinase expression by breast cancer cells in a CCR9-dependent fashion

Breast cancer (BrCa) is one of the most frequently diagnosed cancers and the second leading cause of cancer-related deaths in North American women. Most deaths are caused by metastasis, and BrCa is characterized by a distinct metastatic pattern involving lymph nodes, bone marrow, lung, liver and brain. Migration of metastatic cells share many similarities with leukocyte trafficking, which are regulated by chemokines and their receptors. The current study evaluates the expression and functional role of CCR9, and its only known ligand, CCL25, in BrCa cell migration and invasion. Quantitative immunohistochemical analysis showed that both moderately and poorly differentiated BrCa tissue expressed significantly more (P<0.0001) CCR9 compared to non-neoplastic breast tissue. Interestingly, poorly differentiated BrCa tissue expressed significantly more (P<0.0001) CCR9 compared to moderately differentiated BrCa tissue. Similarly, CCR9 was highly expressed by the aggressive breast cancer cell line (MDA-MD-231) compared to the less aggressive MCF-7. Migration as well as invasion assays were used to evaluate the functional interaction between CCR9 and CCL25 in BrCa cell lines (MDA-MB-231 and MCF-7). Neutralizing CCR9-CCL25 interactions significantly impaired the migration and invasion of BrCa cells. Furthermore, CCL25 enhanced the expression of MMP-1, -9, -11 and -13 active proteins by BrCa cells in a CCR9-dependent fashion. These studies show CCR9 is functionally and significantly expressed by BrCa (poorly > moderately differentiated) tissue and cells as well as that CCL25 activation of this receptor promotes breast tumor cell migration, invasion and MMP expression, which are key components of BrCa metastasis.

Targeted therapies in the management of metastatic bladder cancer

The management of metastatic urothelial carcinoma (UC) of the bladder is a common and complex clinical challenge. Despite the fact that UC is one of the most frequent tumors in the population, long term survival for metastatic disease remains low, and chemotherapy is curative for only a small minority of patients. UC is genetically heterogeneous, and it is surrounded by a complex tissue microenvironment. The problems of clinical practice in the field of metastatic bladder cancer have begun to stimulate translational research. Advances in the understanding of the molecular biology of urothelial cancer continue to contribute to the identification of molecular pathways upon which new therapeutic approaches can be targeted. New agents and strategies have recently been developed which can direct the most appropriate choice of treatment for advanced disease. A review of literature published on the targeted therapy for metastatic bladder cancer is presented, focusing on the molecular pathways shut down by the new therapeutic agents.

hEGR1 is induced by EGF, inhibited by gefitinib in bladder cell lines and related to EGF receptor levels in bladder tumours

The effect of EGF and gefitinib on two EGFR-positive human bladder cancer cell lines has been investigated using array-based gene expression profiling. The most prominent transcript, increased up to 6.7-fold by EGF compared with controls in RT112 cells, was human early growth response protein 1 (hEGR1). This induction was prevented by gefitinib. The hEGR1 mRNA in EGF-treated samples was reduced in the presence of gefitinib, as was hEGR1 protein in cell lysates. In the RT4 cells, hEGR1 expression was halved in the presence of EGF and gefitinib in combination. In bladder tumour samples, there was a significant correlation between hEGR1 mRNA detected by RT-PCR and EGFR detected by ligand binding, (P=0.042). The induction by EGF of the hEGR1 gene, mRNA and protein in RT112 cells, and its inhibition by gefitinib, together with the detection of hEGR1 mRNA in bladder tumours, suggests that hEGR1 may be important in the EGFR growth-signalling pathway in bladder cancer and should be further investigated for its prognostic significance and as a potential therapeutic target.

Molecular Pathways in Invasive Bladder Cancer: New Insights Into Mechanisms, Progression, and Target Identification

Papillary and invasive cancers of the urinary bladder appear to evolve and progress through distinct molecular pathways. Invasion in bladder cancer forebodes a graver prognosis, and these tumors are generally characterized by alterations in the p53 and retinoblastoma (RB) pathways that normally regulate the cell cycle by interacting with the Ras–mitogen activated protein kinase signal transduction pathway. Tumor angiogenesis further contributes to the neoplastic growth by providing a constant supply of oxygen and nutrients. Distinct epigenetic and genetic events characterize the interplay between the molecules involved in these pathways, thus affording their use as indicators of prognosis. Efforts are now underway to construct molecular panels comprising multiple markers that can serve as more robust predictors of outcome. While clinical trials for targeted chemotherapy for bladder cancer have commenced, novel genetic and pharmacologic agents that can target pathway-specific molecules are currently under development. The next generation of clinical management for urothelial carcinoma will witness the use of multimarker panels for prognostic prediction and combination therapy directed at novel molecular targets for treatment.

Extracellular generation of hydrogen peroxide is responsible for activation of EGF receptor by ultraviolet A radiation

Receptor tyrosine kinases such as the epidermal growth factor receptor (EGFR) have been proposed to be activated in cells exposed to ultraviolet A (UVA) radiation (320-400 nm) and to be involved in photocarcinogenesis. Singlet oxygen and hydrogen peroxide are being discussed as mediators of the activation of signal transduction pathways by UVA. It is demonstrated here that EGFR is not activated in cells exposed to UVA in the absence of extracellular photosensitizers. Rather, UVA was capable of activating the EGFR and the related ErbB2 receptor tyrosine kinase in HeLa cells and human keratinocytes only under conditions that allowed for the extracellular photochemical generation of H(2)O(2), such as when cells were covered with cell culture medium during exposure to UVA. Pretreatment of cells with vanadate was required for UVA-induced EGFR activation, pointing to the involvement of protein tyrosine phosphatases. Unlike H(2)O(2), photochemically generated singlet oxygen did not activate EGFR but instead impaired the activation of EGFR by its ligand, EGF. In summary, extracellularly generated H(2)O(2) mediates UVA-induced activation of the EGFR and of ErbB2, whereas intracellular generation of reactive oxygen species upon exposure of cells to UVA is not sufficient for activation of the receptor.

The Study of a Patient's Immune System May Prove to be a Useful Noninvasive Tool for Stage Classification in Colon Cancer

Therapy, and, therefore, prognosis, is strictly related to cancer stage, and hence, screening tests that can contribute to the early classification of disease stage represent a step forward in treatment. Unfortunately, few prognostic indices are available, especially noninvasive ones. Our study of the physiological network of the immune response, however, leads us to believe that it may well be possible to define immunological indices for the classification of cancer stage using blood parameters. In this paper, we show how the study of a patient's immune system can be used as a noninvasive tool for early-stage classification.

Molecular biology of bladder cancer: prognostic and clinical implications

The role of various molecular determinants involved in the genesis, progression, and outcome of bladder cancer has been the focus of investigations for the past 2 decades. Increasingly, the analysis of the interplay between these molecular factors is taking center stage. We review herein the studies examining the effects of deregulation of the various molecules implicated in the cell cycle, apoptosis, and angiogenesis pathways and analyze the central role of p53 in regulating these pathways. Technological advancements enable detection and quantification of gene transcripts and protein products, helping us move toward achieving the goal of establishing diagnostic, prognostic, and therapeutic marker panels. Recent studies have therefore focused on multiple-marker analyses to generate informative panels that can have greater clinical value for bladder cancer management. The use of molecular marker panels can provide a more objective alternative to clinical parameters for diagnosis and treatment decisions. Clinical trials aimed at treating urothelial carcinoma based on a patient's molecular profile can be predicted to empower clinicians to personalize patient management through increased therapeutic efficacy.

Comprehensive profiling and localisation of the matrix metalloproteinases in urothelial carcinoma

The matrix metalloproteinases (MMPs) are endopeptidases which break down the extracellular matrix and regulate cytokine and growth factor activity. Several MMPs have been implicated in the promotion of invasion and metastasis in a broad range of tumours including urothelial carcinoma. In this study, RNA from 132 normal bladder and urothelial carcinoma specimens was profiled for each of the 24 human MMPs, the four endogenous tissue inhibitors of MMPs (TIMPs) and several key growth factors and their receptors using quantitative real time RT–PCR. Laser capture microdissection (LCM) of RNA from 22 tumour and 11 normal frozen sections was performed allowing accurate RNA extraction from either stromal or epithelial compartments. This study confirms the over expression in bladder tumour tissue of well-documented MMPs and highlights a range of MMPs which have not previously been implicated in the development of urothelial cancer. In summary, MMP-2, MT1-MMP and the previously unreported MMP-28 were very highly expressed in tumour samples while MMPs 1, 7, 9, 11, 15, 19 and 23 were highly expressed. There was a significant positive correlation between transcript expression and tumour grade for MMPs 1, 2, 8, 10, 11, 12, 13, 14, 15 and 28 (P<0.001). At the same confidence interval, TIMP-1 and TIMP-3 also correlated with increasing tumour grade. LCM revealed that most highly expressed MMPs are located primarily within the stromal compartment except MMP-13 which localised to the epithelial compartment. This work forms the basis for further functional studies, which will help to confirm the MMPs as potential diagnostic and therapeutic targets in early bladder cancer.

Gefitinib ('Iressa', ZD1839) inhibits the growth response of bladder tumour cell lines to epidermal growth factor and induces TIMP2

The effect of EGF stimulation and its inhibition with gefitinib (‘Iressa’, ZD1839), an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been investigated in two EGFR-positive human bladder tumour cell lines, RT112 and RT4. The growth of RT112 cells in a medium containing 10% foetal bovine serum was inhibited by 50% with 10 μM gefitinib, whereas this dose completely inhibited RT4 cell growth. Cells were more sensitive to growth inhibition in the serum-free medium. Increased growth of cells in the serum-free medium was observed with 10 or 50 ng ml⁻¹ EGF and the proliferative effect of EGF stimulation in both cell lines was inhibited in the presence of 1 μM, but not 0.1 μM gefitinib. Zymography of the conditioned medium from RT112 cells treated with EGF and gefitinib showed a decrease in matrix metalloproteinase 2 (MMP2) concentrations. Western blot analysis showed that tissue inhibitor of metalloproteinase 1(TIMP1) increased in the conditioned medium from RT112 cells treated with EGF, and this was partially inhibited with both 1 and 5 μM gefitinib. Conversely, TIMP2 decreased with EGF stimulation and this was reversed with gefitinib. Tissue inhibitor of metalloproteinase 1 had no effect on the growth of either cell line. These studies show alterations in the balance of MMPs and their inhibitors in EGF-stimulated bladder tumour cells, which are reversed by gefitinib, suggesting gefitinib should be investigated for its effect on human bladder tumours.

Matrix metalloproteinases (MMPs) in bladder cancer: the induction of MMP9 by epidermal growth factor and its detection in urine

OBJECTIVES

To investigate the matrix metalloproteinases (MMPs) 2 and 9 in bladder cancer cell lines stimulated with epidermal growth factor (EGF), and to investigate the presence of gelatinases in the urine of patients with bladder tumours, in relation to the stage and grade of tumour and the EGF receptor (EGFR) status.

PATIENTS, SUBJECTS AND METHODS

Conditioned media from cultured tumour cells were analysed by zymography. Urine samples from 28 patients with transitional cell carcinoma and 12 normal volunteers were also analysed. Western blotting was used to verify the bands of gelatinolytic activity. The EGFR status of the tumours was assessed by immunohistochemistry.

RESULTS

MMP9 was induced by EGF in the RT112 but not the RT4 bladder tumour cell line, whereas MMP2 production was unaffected by EGF. Gelatin zymography of urine samples from patients with bladder tumours showed high levels of MMP activity, with 78% positive for MMP9 and 28% positive for MMP2. The total gelatinolytic and MMP9 activity were significantly higher in patients with high-stage invasive tumours than in those with superficial tumours (P < 0.05), and were higher than in normal controls. Gelatinolytic activity at 130 and 200 kDa in urine was identified as MMP9 and MMP2. There was no significant relationship of urinary MMP9 activity to EGFR status of the tumour.

CONCLUSION

EGF induces MMP9 but not MMP2 in bladder cells. Analysis of urinary gelatinases is a useful noninvasive technique and both total gelatinase and MMP9 activity are associated with high stages of bladder tumours.

Epidermal growth factor receptor and bladder cancer

Muscle-invasive bladder cancer is a disease which causes significant morbidity and mortality. The two main forms of treatment for this disease include radical cystectomy and radical radiotherapy, but five year survival after treatment remains low at 40%. Many clinical and molecular risk factors have been shown to be associated with poor prognosis. One such factor is the expression of epidermal growth factor receptor (EGFR), which is overexpressed by many epithelial tumours, including bladder cancers. There are several methods of inhibiting the activity of EGFR and it may be that use of an anti-EGFR therapy, in combination with more conventional treatment, provides a method of improving the prognosis for muscle-invasive bladder cancer.

Angiogenesis in bladder cancer--prognostic marker and target for future therapy

Angiogenesis is the process by which tumours induce a blood supply, crucial for growth and metastasis. Evidence for its role in bladder carcinogenesis, its usefulness as a marker of patient prognosis, and potential anti-angiogenic therapies for future development are discussed in this chapter.

Quantification of matrix metalloproteinase activity in plasma of patients enrolled in a BAY 12-9566 phase I study

The expression of matrix metalloproteinases (MMPs) is often associated with invasiveness or grade of tumours. Increased blood levels of MMP proteins, including MMP-1, MMP-2, MMP-3 and MMP-9 have been detected in various types of cancers. With the exception of one study, MMPs in serum and plasma have been determined using ELISA. In the present study we measured the activity of the MMPs found in human plasma samples using gelatin enzymography and fluorimetric degradation assays. We used plasma samples from healthy control subjects and cancer patients enrolled in a dose-finding study for the MMP inhibitor, BAY 12-9566, to assess the activity of MMPs found in plasma and screen for efficacy of the MMP inhibitor. BAY 12-9566 has inhibitory activity toward MMP-2, MMP-3 and MMP-9. Patients with advanced solid tumours were enrolled in our study and plasma was collected on day 1 before dosing and at steady-state of the drug on day 15. Our results show that BAY 12-9566 was effective in lowering the plasma gelatinolytic activity in the group of 29 patients when considering the data obtained from a fluorimetric gelatinase assay. The data obtained from gelatin enzymography, however, did not reach significance. The fluorimetric degradation assay could be a useful tool to screen plasma from cancer patients in other clinical trials assessing MMP inhibitors.

The epidermal growth factor receptor and its inhibition in cancer therapy

Much effort has been expended in the search for inhibitors of signalling molecules that may prove to be important therapeutically in cancer. The epidermal growth factor receptor (EGFR) family and their associated ligands has been one such area extensively investigated. The complex nature of EGFR biology allows for potential opportunities for EGFR inhibitors in a number of areas of cancer therapy, including proliferative, angiogenic, invasive, and metastatic aspects. Much positive evidence of likely benefit has already been gathered from a multiplicity of laboratory experiments. Clinical trials are now urgently required to further evaluate the advantages of such agents.