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

Integrated genomic and transcriptional analysis of the in vitro evolution of telomerase-immortalized urothelial cells (TERT-NHUC)

Much progress has been made in identifying the molecular genetic alterations that occur in bladder cancer. However, in many cases the genes targeted by these alterations are not known. Telomerase immortalized human urothelial cells (TERT-NHUC) are a useful resource for in vitro studies of genes involved in urothelial transformation. When cultured under standard conditions they remain genetically stable but when cultured under low-density conditions they exhibit genetic instability and acquire chromosomal alterations. TERT-NHUC from three donors were cultured at low plating density and examined at four time-points during a culture period of 600 days. Analyses included population doubling kinetics, array-based CGH (aCGH), chromosome counts, fluorescence in situ hybridization (FISH), mutation analysis, Affymetrix gene expression analysis, Western blotting for p16, anchorage-independent growth and tumorigenicity assays. Alterations acquired during continued culture of TERT-NHUC at low density (TERT-NHUC-L) included some observed in urothelial carcinoma (UC) cell lines and primary UC. Examination of gene expression in TERT-NHUC with distinct acquired genetic aberrations may pinpoint genes targeted by these alterations. Data from an aCGH study of UC cell lines and primary tumors were examined for changes in chromosomal regions that also showed alterations in TERT-NHUC-L. Loss of a region on 2q including BOK was identified in UC cell lines and primary tumors. DNER and FRAS1 were identified as potential candidate genes, whose expression is altered independently of the acquisition of any genetic event.

A single-arm, multicenter, open-label phase 2 study of lapatinib as the second-line treatment of patients with locally advanced or metastatic transitional cell carcinoma

BACKGROUND

The treatment of recurrent transitional cell carcinoma (TCC) remains an unmet clinical need. This study assessed lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and HER-2, as second-line therapy in patients with locally advanced or metastatic TCC.

METHODS

This was a single-arm, multicenter, open-label, prospective phase 2 study. Patients with TCC whose disease progressed on prior platinum-based chemotherapy received lapatinib until disease progression or unacceptable toxicity, with evaluations for response by Response Evaluation Criteria In Solid Tumors criteria performed every 8 weeks. The primary endpoint of the current study was objective tumor response rate. Secondary endpoints included safety, time to disease progression, and overall survival.

RESULTS

Fifty-nine patients were enrolled in the study, 25 of whom (42%) could not be evaluated for response. The primary endpoint of an objective response rate (ORR) >10% was observed in 1.7% (95% confidence interval [95% CI], 0.0%-9.1%) of patients; however, 18 (31%; 95% CI, 19%-44%) patients achieved stable disease (SD). The median time to disease progression and overall survival (OS) were 8.6 weeks (95% CI, 8.0 weeks-11.3 weeks) and 17.9 weeks (95% CI, 13.1 weeks-30.3 weeks), respectively. Clinical benefit (ORR and SD) was found to be correlated with EGFR overexpression (P = .029), and, to some extent, HER-2 overexpression. The median OS was significantly prolonged in patients with tumors that overexpressed EGFR and/or HER-2 (P = .0001). Lapatinib was well tolerated.

CONCLUSIONS

The study was considered to be negative because it did not meet its primary endpoint; however, further analysis demonstrated an improvement in OS in a subset of patients with tumors overexpressing EGFR and/or HER-2, which is encouraging and warrants further investigation.

Management of muscle-invasive bladder cancer: an update

The aim of this Review is to critically assess the currently used methods for the treatment of muscle-invasive bladder cancer. Radical cystectomy seems to be the gold standard for the treatment of bladder cancer, and the optimum extent of lymph-node dissection has now been identified. An early cystectomy should be carried out once a diagnosis of muscle invasion is established. Preoperative radiation is no longer popular, but could be due a reassessment in view of technical advances. Results of neoadjuvant and adjuvant chemotherapy trials are subject to criticism. Most trials are retrospective, used different chemotherapy protocols and did not have uniform end point assessment. Bladder-preservation strategies can offer cures for a selection of subpopulations, but these patient groups have yet to be clearly defined. Developments in molecular biology are exciting, and their potential application is pending translational research. To be meaningful and useful, future trials that involve additional or alternative modalities should be prospective, randomized and adequately powered.

Des-gamma-carboxy prothrombin stimulates human vascular endothelial cell growth and migration

Des-gamma-carboxy prothrombin (DCP) is an aberrant prothrombin produced by hepatocellular carcinoma (HCC) cells. Serum and tissue DCP expressions are thought to reflect the biological malignant potential of HCC. However, the role of DCP in the development of angiogenesis is not well understood. Herein, we report the effects of DCP on growth and migration of human vascular endothelial cells. DCP significantly stimulated the proliferation of HUVEC (ECV304) cells in a dose and time dependent manner, as measured by the MTT assay. A continuous rapid migration of ECV304 cells was observed in the presence of DCP measured by the scratch wound assay. The continuous rapid invasive activity, measured by transwell chamber assay also showed that DCP increased endothelial cells migration through the reconstituted extracellular matrix (Matrigel). Further, the tube formation of vascular endothelial cells on 3-D Matrigel showed an increased number of branch points of ECV304 cells induced by DCP in a dose dependent manner. The levels of vascular endothelial cell growth-related angiogenic factors and matrix metalloproteinase were also examined. DCP significantly stimulated the expression levels of epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-2 (latent and active). Together, these data suggest that DCP is a novel type of vascular endothelial growth factor that possesses potent mitogenic and migrative activities in angiogenesis of HCC.

A phase II trial of cisplatin (C), gemcitabine (G) and gefitinib for advanced urothelial tract carcinoma: results of Cancer and Leukemia Group B (CALGB) 90102

BACKGROUND

This phase II trial (Cancer and Leukemia Group B 90102) sought to determine the efficacy of cisplatin, standard infusion of gemcitabine and gefitinib in patients with advanced urothelial carcinoma.

PATIENTS AND METHODS

Eligible patients had previously untreated measurable disease, Eastern Cooperative Oncology Group (ECOG) performance status of zero to two and creatinine clearance >50 ml/min. Treatment consisted of cisplatin 70 mg/m(2) day 1 and gemcitabine 1000 mg/m(2) on days 1 and 8 given every 3 weeks concurrent with gefitinib 500 mg/day orally for six cycles. Maintenance gefitinib 500 mg/day was continued for responding or stable disease.

RESULTS

Fifty-four of 58 patients were assessable. Twelve patients (22%) had node-only disease, and 25 (46%) had an ECOG performance status of zero. There were 23 objective responses for an overall response rate of 42.6% [95% confidence interval (CI) 29.2% to 56.8%]. The median survival time was 15.1 months (95% CI 11.1-21.7 months) and the median time to progression was 7.4 months (95% CI 5.6-9.2 months).

CONCLUSIONS

The combination of cisplatin, gemcitabine and gefitinib is well tolerated and active in advanced transitional cell carcinoma. The addition of gefitinib does not appear to improve response rate or survival in comparison to historical controls of cisplatin and gemcitabine alone.

Randomized, double-blind, placebo-controlled phase II trial of maintenance sunitinib versus placebo after chemotherapy for patients with advanced urothelial carcinoma: scientific rationale and study design

Systemic chemotherapy is the primary treatment modality for patients with advanced urothelial cancer. However, despite a high initial response rate, durable responses are rare. Angiogenesis has been shown to be important in the development and progression of urothelial cancer. Sunitinib, an oral, multi-targeted, small-molecule inhibitor of multiple tyrosine kinases, is known to inhibit angiogenesis and therefore might decrease progression of urothelial cancer. This phase II trial was designed to investigate the role of sunitinib as maintenance therapy in patients with advanced urothelial cancer. The specific hypothesis of this trial is that sunitinib will decrease progression rates in patients with advanced urothelial cancer who have obtained stable disease or better after standard chemotherapy.

The type 1 insulin-like growth factor receptor is over-expressed in bladder cancer

OBJECTIVE

To analyse bladder cancer biopsies and investigate the pattern of expression of the type 1 insulin-like growth factor receptor (IGF1R), a receptor tyrosine kinase that mediates tumour cell proliferation, motility and protection from apoptosis.

MATERIALS AND METHODS

Formalin-fixed specimens of bladder cancer (40 whole-mount, 80 cores on a tumour microarray) and normal bladder (15 samples) were stained immunohistochemically for the IGF1R. The IGF1R expression was also measured by quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) on RNA extracted from fresh frozen bladder cancers (61) and benign bladder (12).

RESULTS

Of the 15 samples of normal bladder, 14 showed negligible (1+) or light (2+) IGF1R immunostaining. By contrast moderate (3+) or heavy (4+) staining for IGF1R was detected in 89 (74%) of the 120 samples of malignant urothelium. Q-RT-PCR showed significantly higher levels of steady-state IGF1R mRNA in tumours (all cases, Ta-T4) than in normal bladder (P < 0.05), indicating up-regulation at the transcriptional level. This difference was particularly evident when comparing normal urothelium with superficial (Ta-T1) or invasive (T2-4) tumours; only the latter showed significant IGF1R over-expression at the RNA level (P < 0.05 vs normal bladder).

CONCLUSION

The IGF1R is up-regulated in bladder cancer compared with non-malignant bladder, and might contribute to a propensity for invasion.

A phase II trial of cisplatin, fixed dose-rate gemcitabine and gefitinib for advanced urothelial tract carcinoma: results of the Cancer and Leukaemia Group B 90102

OBJECTIVE

To conduct a phase II trial to determine the efficacy of cisplatin, a fixed dose-rate infusion of gemcitabine and gefitinib (an orally active epidermal growth factor receptor tyrosine kinase inhibitor) in patients with advanced urothelial carcinoma.

PATIENTS AND METHODS

Eligible patients had previously untreated measurable disease, an Eastern Cooperative Oncology Group performance status of 0-2 and creatinine clearance of >50 mL/min. The treatment regimen consisted of cisplatin 70 mg/m(2) on day 1, gemcitabine 1000 mg/m(2) on day 1 and 8, administered at a fixed dose rate of 10 mg/m(2)/min, given every 3 weeks concurrent with gefitinib 500 mg/day orally for a maximum of six cycles. Maintenance gefitinib 500 mg/day was continued for responding or stable disease.

RESULTS

In all, 27 patients were accrued before the study was halted because the dose-limiting toxicity (DLT) exceeded pre-established stopping rules. The DLT events were two grade 5 (one infection, one cardiovascular accident) and three with grade 4 non-haematological toxicity. In 25 evaluable patients there were nine objective responses, for an overall response rate of 36% (95% confidence interval, CI, 18-57%). The median (95% CI) survival time was 11.1 (5.2-35.3) months.

CONCLUSION

The combination of cisplatin, fixed dose-rate gemcitabine and gefitinib is active in advanced TCC, although the relative contribution of gefitinib cannot be determined. However, this regimen was associated with excessive toxicity.

Targeting EGFR in bladder cancer

Expression and overexpression of the epidermal growth factor receptor (EGFR) have been described in several solid tumors including bladder, breast, colorectal, NSCLC, prostate, and ovarian cancers. In addition to gene amplification, point mutations within the kinase domain also occur. Previous reports indicate that the patient's response to gefitinib depends on either the presence of mutations within the kinase domain of EGFR or the expression of the most frequent alteration, the truncated EGFR variant III (EGFRvIII). Therefore, it is important to determine if these EGFR alterations are present in urothelial carcinoma. The kinase domain of EGFR (exons 18-21) from 11 bladder cancer cell lines as well as from 75 patient tumors was analyzed by automated sequencing. No mutations were detected in all samples tested. Furthermore, analysis of EGFRvIII by immunohistochemistry revealed that almost half of all the patient samples expressed this truncation in a urothelial carcinoma tissue microarray. However, there have been previous reports of inconsistencies in detecting EGFRvIII by immunohistochemistry owing to the specificity of the antibodies and the methodologies utilized. Therefore, these results were validated by reverse transcription PCR, real-time PCR and western blot analysis. In these assays, none of the samples tested positive for EGFRvIII. Taken together, these results indicate that mutations within the tyrosine kinase domain of EGFR and expression of EGFRvIII are rare events in bladder cancer and therefore do not contribute to the malignant phenotype of this tumor. These results have clinical implications in selecting tyrosine kinase inhibitors for the therapy of urothelial carcinoma.

HER-2/neu raises SHP-2, stops IFN-γ anti-proliferation in bladder cancer

Gene amplification or HER-2/neu protein overexpression signals a poor outcome for bladder cancer patients. We investigated the anti-proliferative effect of IFN-gamma in HER-2/neu-transfected human bladder cancer cells (TCC-N5 and TCC-N10). The cells continued growing after IFN-gamma stimulation but did not activate the Janus kinase (Jak)/Stat pathway. We found Jak/Stat protein phosphatase in TCC-N5 and TCC-N10 cells with upregulated Src homology 2-containing protein tyrosine phosphatase-2 (SHP-2). After the cells had been treated with AG825, a HER-2/neu-specific inhibitor, SHP-2 expression declined, and Jak2/Stat1 reactivated. Similar results were reported in a mouse bladder cancer cell line, MBT2, with constitutive HER-2/neu overexpression. Further, AG825 pretreatment restored the anti-proliferation activity of IFN-gamma in TCC-N5 and TCC-N10 cells. Therefore, the suppression of IFN-gamma signaling in HER-2/neu-overexpressing bladder cancer cells might be due to SHP-2 upregulation. The regulation of SHP-2 by HER-2/neu provides a new target for blocking the HER-2/neu oncogenic pathway.

Chemotherapy for Metastatic or Unresectable Bladder Cancer

Cisplatin, methotrexate, doxorubicin, and vinblastine (M-VAC) combination chemotherapy has been the historic standard of care in patients with advanced urothelial tumors. Phase III trials have evaluated new combinations such as gemcitabine/cisplatin (GC), carboplatin/paclitaxel, docetaxel/cisplatin, and interferon-alpha/5-fluorouracil/cisplatin. However, these new regimens have failed to demonstrate superiority in terms of overall survival when compared with classic M-VAC. The GC doublet has proved to be a new standard treatment alternative based on an improved toxicity profile and similar survival results. The addition of a third agent (paclitaxel) to this regimen is the focus of a phase III trial. However, long-term follow-up with classical and new regimens (doublets and triplets) still show limited efficacy and emphasize the need to identify more active treatment. For "unfit" patients, ie, those unable to receive cisplatin-based regimens, conventional regimens include methotrexate, carboplatin, and vinblastine (M-CAVI), carboplatin-gemcitabine, carboplatin-paclitaxel, gemcitabine-taxane, or monotherapy with either gemcitabine, carboplatin, or a taxane. New drugs, including pemetrexed and vinflunine, are now being studied for salvage therapy. In addition to new active drug combinations and targeted therapies, chemotherapy optimization using molecular characteristics to predict chemosensitivity is emerging.

Gene expression of ERCC1 as a novel prognostic marker in advanced bladder cancer patients receiving cisplatin-based chemotherapy

BACKGROUND

Customizing chemotherapy on the basis of chemosentitivity prediction may improve outcome in advanced bladder cancer patients. Since DNA damaging agents are the cornerstones of therapy, we hypothesized that levels of DNA repair genes could predict survival.

PATIENTS AND METHODS

Messenger RNA expression levels of excision repair cross complementing 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and caveolin-1 were determined by RT-PCR in tumor DNA from 57 advanced and metastatic bladder cancer patients treated with either gemcitabine/cisplatin or gemcitabine/cisplatin/paclitaxel (Taxol). Levels were correlated with survival, time to disease progression and chemotherapy response.

RESULTS

Median survival was significantly higher in patients with low ERCC1 levels (25.4 versus 15.4 months; P = 0.03) (median follow-up 19 months). A trend towards longer time to progression was observed in patients with tumors expressing low levels of all markers. Levels of RRM1, BRCA1 and caveolin-1, however, failed to predict the survival and a clear link with chemotherapy response could not be established. On multivariate analysis with pretreatment prognostic factors, ERCC1 emerged as an independent predictive factor for survival.

CONCLUSION

The results of the study indicate that ERCC1 may predict survival in bladder cancer treated by platinum-based therapy.

Trimodality Treatment and Selective Organ Preservation for Bladder Cancer

Standard treatment for muscle-invasive bladder cancer is cystectomy. Trimodality treatment, including transurethral resection of the bladder tumor (TURBT), radiation therapy and chemotherapy, has been shown to produce survival rates comparable to those of cystectomy. With these programs, cystectomy has been reserved for patients with incomplete response or local relapse. During the past 15 years, organ preservation by trimodality treatment has been investigated in prospective series from single centers and cooperative groups, with more than 1,000 patients included. Five-year overall survival rates in the range of 50% to 60% have been reported, and approximately three quarters of the surviving patients maintained their bladder. Clinical criteria helpful in determining ideal patients for bladder preservation include early tumor stage (including high-risk T1 disease), a visibly complete TURBT, and absence of ureteral obstruction. Close coordination among all disciplines is required to achieve optimal results. Future investigations will focus on (1) optimizing radiation techniques and incorporating more effective systemic chemotherapy, and (2) the proper selection of patients based on molecular makers.

Reactive oxygen species regulate epidermal growth factor-induced vascular endothelial growth factor and hypoxia-inducible factor-1alpha expression through activation of AKT and P70S6K1 in human ovarian cancer cells

The epidermal growth factor (EGF) and EGF receptor (EGFR) family are often overexpressed in various human cancers including ovarian cancer. While it is generally believed that reactive oxygen species (ROS) are involved in the intracellular signaling events, the role of ROS in EGF-induced angiogenesis and carcinogenesis remains to be elucidated. The present study investigated the role of ROS in the regulation of AKT, p70S6K1, vascular endothelial growth factor (VEGF), and hypoxia-inducible factor 1 (HIF-1) in ovarian cancer cells. In this study, OVCAR-3 cells were treated with EGF and catalase, an H2O2 scavenger. EGF treatment increases H2O2 production, leading to activation of the AKT/p70S6K1 pathway, resulting in increased VEGF expression at the transcriptional level. The inhibition of H(2)O(2) production by catalase abolished EGF-induced AKT and p70S6K1 activation, and VEGF expression through HIF-1alpha expression. Forced expression of p70S6K1 and HIF-1alpha reversed catalase- and rapamycin-inhibited VEGF transcriptional activation. We also showed that rapamycin, p70S6K1 inhibitor and catalase overexpression inhibited tumor angiogenesis. This study demonstrates a novel mechanism of EGF-induced VEGF and HIF-1alpha expression through production of H2O2 and activation of AKT and p70S6K1 in human ovarian cancer cells. This study also indicates that p70S6K1 and H2O2 are important in tumor angiogenesis. The results of the study could have an important implication in ovarian cancer therapy.

Emerging role of tyrosine kinase inhibitors in the treatment of advanced renal cell cancer: a review

Advanced and metastatic renal cell cancer (RCC) is resistant to conventional chemotherapy. Only a very small number of patients survive long term after immunotherapy. However, any effect of interleukin-2 (IL-2) and/or interferon on median overall survival is small, and treatment-associated toxicities may be severe. The disease is therefore an area of high unmet medical need. Activation of the VEGF and EGF/RAS/RAF/MAP kinase pathways is frequent in solid tumours such as RCC. Such activation is implicated in tumour angiogenesis and proliferation. VEGF and EGF receptors and molecules (such as RAF kinase) involved in downstream signalling are therefore potential appropriate targets for drug therapy. Several antibodies and low molecular weight tyrosine kinase inhibitors (TKIs) have completed phase II clinical trials. Phase II studies of multitargeted agents, which include inhibition of VEGFR tyrosine kinase in their repertoire (sorafenib, sunitinib and AG 013736), show clear second-line activity in metastatic RCC. The same is true of the anti-VEGF antibody, bevacizumab. In a randomised phase III comparison against placebo in pretreated patients, sorafenib doubled median progression free survival (24 versus 12 weeks). Studies now in progress will determine whether benefits seen second-line will also be evident first-line, and whether the activity of novel agents can be increased by combining them with each other, with cytokines, or with chemotherapy.

Dual-track pathway of bladder carcinogenesis: practical implications

CONTEXT

The concept of a dual-track pathway in bladder carcinogenesis postulates that bladder cancer develops via 2 distinct but somewhat overlapping pathways, termed the papillary and nonpapillary. Approximately 80% of bladder carcinomas consist of superficial exophytic papillary lesions that originate from urothelial hyperplasia. These typically low-grade papillary tumors may recur, but they rarely invade the bladder wall or metastasize. The remaining 15% to 20% of tumors represent high-grade solid nonpapillary bladder carcinoma, which arise from high-grade intraurothelial neoplasia. These tumors aggressively invade the bladder wall and have a high propensity for distant metastasis.

OBJECTIVE

To summarize the scientific literature and provide a clinicopathologic review of the dual-track concept of bladder carcinogenesis with its important implications.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) between 1974 and 2005.

CONCLUSIONS

Although the characteristics of papillary and nonpapillary tumors are quite dissimilar, current evidence implies that both forms of bladder cancer start as a clinically occult clonal expansion of preneoplastic lesions that occupy large areas of the bladder mucosa.

Is Quantitative Real-Time RT-PCR an Adjunct to Immunohistochemistry for the Evaluation of ErbB2 Status in Transitional Carcinoma of the Bladder?

OBJECTIVE

To test different approaches of evaluation of the ErbB2 status in a large series of human transitional cell carcinoma (TCC) of the bladder with the prospect of finding targeted therapies.

METHODS

ErbB2 status of 73 human TCC samples was analyzed by both immunohistochemistry (IHC) and by quantification of mRNA levels of expression using real-time reverse transcription-polymerase chain reaction (RT-PCR). Additionally, 18 bladder samples were studied for ERBB2 gene amplification by real-time quantitative PCR.

RESULTS

Twenty-five tumors (34.2%) overexpressed ERBB2 mRNA compared to normal bladder samples; this alteration appeared in low-grade and low-stage tumors (pTaG1). Twenty-four (32.9%) tumors showed moderate (++) or strong (+++) immunostaining. A very strong agreement was found between the two methods (kappa = 0.97, 95% confidence interval, 0.90-1). ErbB2 status was not associated with tumor stage. Of the 18 bladder samples tested for ERBB2 gene amplification, only one showed ERBB2 DNA amplification.

CONCLUSIONS

ErbB2 overexpression occurs in about one third of bladder TCCs. This overexpression can be detected by RT-PCR with a very good correlation with IHC. RT-PCR can therefore be used for cases considered doubtful on IHC rather than gene amplification studies because, in TCC, gene amplification is not the predominant mechanism of both mRNA and protein overexpression. Accurate quantification of ErbB2 status is mandatory for the use of anti-ErbB2-targeted therapies in bladder TCC.

Gefitinib Inhibits the Growth and Invasion of Urothelial Carcinoma Cell Lines in which Akt and MAPK Activation Is Dependent on Constitutive Epidermal Growth Factor Receptor Activation

PURPOSE

Abnormally high levels of epidermal growth factor receptor (EGFR) protein are associated with advanced tumor stage/grade. The objective of this study was to evaluate the effects of the specific EGFR tyrosine kinase inhibitor gefitinib on activation of the Akt and mitogen-activated protein kinase (MAPK) pathways in human urothelial cell carcinoma (UCC) cell lines and to identify potential markers of gefitinib responsiveness in biopsy samples of UCC.

EXPERIMENTAL DESIGN

Changes in markers of UCC growth and invasion after exposure to gefitinib were studied in six human UCC cell lines expressing various levels of EGFR. The findings were related to activation of Akt and MAPK. We studied the influence of gefitinib on intraepithelial expansion of the responsive 1207 cell line. EGFR, Akt, and MAPK activation was studied by Western blot analysis of a panel of 57 human UCC.

RESULTS

Gefitinib had a growth-inhibitory and anti-invasive effect in two of six UCC cell lines (i.e., 647V and 1207). Gefitinib was also able to block the expansion of 1207 at the expense of normal urothelial cells. These effects did not depend on the level of expression of EGFR but they were associated with the down-regulation of MAPK and Akt activity; in 1207 cells, gefitinib activity was associated with p27 up-regulation and p21 and matrix metalloproteinase-9 down-regulation. Similarly, the Akt and MAPK pathways were found to be strongly phosphorylated in association with EGFR activation in a subset of human UCC specimens.

CONCLUSIONS

Activation of EGFR, Akt, and MAPK defines a subset of UCC which might provide information for the identification of gefitinib responders.

Gene Expression Profiling of ERBB Receptors and Ligands in Human Transitional Cell Carcinoma of the Bladder

PURPOSE

The ErbB driven growth pathway has been implicated in most human epithelial malignancies. Therefore, its blockade is a promising therapeutic strategy and several candidate drugs are currently undergoing clinical trials. Paradoxically little is known of the expression pattern or clinical significance of the 4 ErbB receptors and their 11 ligands in TCC of the bladder.

MATERIALS AND METHODS

To obtain further insight into the molecular pathogenesis of TCC we used quantitative real-time reverse transcriptase-polymerase chain reaction assay to quantify mRNA expression of the 4 ERBB and their 11 known ligand genes, including recently described EPGN/epigen, in 73 tumor samples.

RESULTS

The level of mRNA of 4 ligand genes (EGF, NRG1, NRG2 and NRG3) was extremely low, that is detectable but not quantifiable. Six genes were over expressed (ERBB2, TGFA, HB-EGF, AREG, EREG and EPGN), 3 were under expressed (ERBB1, ERBB4 and NRG4) and 2 were over or under expressed (ERBB3 and BTC). ERBB2 and AREG expression differed between early stage tumors (pTa grade 1) and normal samples. The most marked differences in expression were ERBB3, EREG and NRG4 between superficial and muscle invasive tumors (p = 0.0069, 0.00007 and 0.0000001, respectively), and TGFA and NRG4 between low and high grade superficial tumors, and between pT1 or greater and pTa tumors.

CONCLUSIONS

This study shows the involvement of the ERBB family and ligand genes in TCC. Most receptor and ligand genes are deregulated at different stages of carcinogenesis, implying that they should be studied simultaneously. Quantitative real-time reverse transcriptase-polymerase chain reaction could be used to determine ErbB signaling pathway status in individuals with a view to tailored therapy.

Expression of EphA2 and Ephrin A-1 in carcinoma of the urinary bladder

PURPOSE

The EphA2 receptor tyrosine kinase is believed to play a role in tumor growth and metastasis. The clinical significance of the expression of EphA2 was observed in breast, prostate, colon, skin, cervical, ovarian, and lung cancers. The purpose of this work was to determine the expression of EphA2 and its ligand, Ephrin A-1, and E-cadherin in carcinoma of the urinary bladder, and determine EphA2 as a new target for therapy in bladder cancer.

EXPERIMENTAL DESIGN

EphA2 mRNA and protein expression was investigated by reverse transcription-PCR and Western blot, respectively, in bladder cancer cell lines. In addition, the expression of EphA2, Ephrin A-1, and E-cadherin in tissues from patients with different stages of urinary bladder cancer was determined by immunohistochemistry. Furthermore, the ability of Ephrin A-1 to inhibit growth of bladder cancer cells was also investigated using an adenoviral delivery system.

RESULTS

Western blot analysis showed high EphA2 expression in TCCSUP, T24, and UMUC-3 cell lines. In tissues, the staining intensity of EphA2 was less in normal urothelium but increased greatly in advancing stages of urothelial carcinoma (P < 0.05). Similarly, the staining intensity of Ephrin A-1 was low in normal tissues and high in cancerous tissues, but it was similar across the various stages of urothelial carcinoma (T(a)-T(4)). E-cadherin immunoreactivity decreased in urothelial cancer. Association of EphA2 and Ephrin A-1 expression was found to be significant between T(a) stage and T(1)-T(2) (P < 0.04) and T(a) and T(3)-T(4) stages (P < 0.0001). Adenovirus delivery of Ephrin A-1 inhibited proliferation of TCCSUP cells.

CONCLUSION

EphA2 may serve as a novel target for bladder cancer therapy.

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.

Trafficking of nuclear heparin-binding epidermal growth factor-like growth factor into an epidermal growth factor receptor-dependent autocrine loop in response to oxidative stress

Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) accumulates in the nucleus in aggressive transitional cell carcinoma (TCC) cells and this histologic feature is a marker of poor prognosis in human bladder cancer tissues. Here we report that HB-EGF can be exported from the nucleus during stimulated processing and secretion of the growth factor. Production of reactive oxygen species (ROS) resulted in mobilization of the HB-EGF precursor, proHB-EGF, from the nucleus of TCCSUP bladder cancer cells to a detergent-resistant membrane compartment, where the growth factor was cleaved by a metalloproteinase-mediated mechanism and shed into the extracellular space. Inhibition of nuclear export suppressed HB-EGF shedding. Production of ROS resulted in EGF receptor (EGFR) and Akt1 phosphorylation in HB-EGF-expressing cells. HB-EGF also stimulated cell proliferation and conferred cytoprotection when cells were challenged with cisplatin. These findings show that the nucleus can serve as an intracellular reservoir for a secreted EGFR ligand and, thus, can contribute to an autocrine loop leading to cell proliferation and protection from apoptotic stimuli.

Recent developments in advanced urothelial cancer

PURPOSE OF REVIEW

Metastatic or unresectable urothelial cancer of the urinary bladder has traditionally been treated with systemic chemotherapy, which is most often platinum-based. The long-term survival data and the associated toxicities from this form of therapy have spurred continuing interest in finding novel treatment options for this malignancy.

RECENT FINDINGS

Recently, trials of new chemotherapy combinations, many incorporating platinum analogs or deleting platinum entirely, have been reported. None has yet been shown to be superior to cisplatin-based regimens. In addition, recent advances in imaging and laboratory technologies have provided new avenues to understand urothelial cancer behavior and prognosis. These advances provide optimism for improvements in the diagnosis, staging, and ultimately, selection of therapy for patients with urothelial cancer.

SUMMARY

This review will summarize recent developments (circa 2004) in the diagnosis and management of advanced bladder cancer.

Urothelial tumorigenesis: a tale of divergent pathways

Urothelial carcinoma of the bladder is unique among epithelial carcinomas in its divergent pathways of tumorigenesis. Low-grade papillary tumours rarely become muscle-invasive and they frequently harbour gene mutations that constitutively activate the receptor tyrosine kinase-Ras pathway. By contrast, most high-grade invasive tumours progress to life-threatening metastases and have defects in the p53 and the retinoblastoma protein pathways. Correcting pathway-specific defects represents an attractive strategy for the molecular therapy of urothelial carcinomas.

The Current and Future Application of Adjuvant Systemic Chemotherapy in Patients with Bladder Cancer Following Cystectomy

Urothelial transitional cell cancer has a high rate of response to combination cytotoxic therapy. Approximately 50% of patients with high-grade bladder cancer and deep muscle invasion ultimately die of disseminated disease. Translating the high response seen in locally advanced disease into long-term survival in the metastatic setting and to improved survival in the advanced setting has proved difficult. This article reviews the use of adjuvant chemotherapy in localized or locally advanced transitional cell cancer. The chemotherapy of urological malignancies, including bladder cancer, has recently been reviewed in detail; this article does not contain an extensive review of the drugs used.

Loss of expression of the adipocyte-type fatty acid-binding protein (A-FABP) is associated with progression of human urothelial carcinomas

Bladder cancer is the fifth most common malignancy in the world and represents the second most common cause of death among genitourinary tumors. Current prognostic parameters such as grade and stage cannot predict with certainty the long-term outcome of bladder cancer, and as a result there is a pressing need to identify markers that may predict tumor behavior. Earlier we identified the adipocyte fatty acid-binding protein (A-FABP), a small-molecular-mass fatty acid-binding protein that functions by facilitating the intracellular diffusion of fatty acids between cellular compartments as a putative marker of progression based on a limited study of fresh bladder urothelial carcinomas (UCs) (Celis, J. E., Ostergaard, M., Basse, B., Celis, A., Lauridsen, J. B., Ratz, G. P., Andersen, I., Hein, B., Wolf, H., Orntoft, T. F., and Rasmussen, H. H. (1996) Loss of adipocyte-type fatty acid binding protein and other protein biomarkers is associated with progression of human bladder transitional cell carcinomas. Cancer Res.56, 4782-4790). Here we have comprehensively examined the protein expression profiles of a much larger sample set consisting of 153 bladder specimens (46 nonmalignant biopsies, 11 pTa G1, 40 pTa G2, 10 pTa G3, 13 pT1 G3, 23 pT2-4 G3, and 10 pT2-4 G4) by gel-based proteomics in combination with immunohistochemistry (IHC) using a peptide-based rabbit polyclonal antibody that reacts specifically with this protein. Proteomic profiling showed a striking down-regulation of A-FABP in invasive lesions, a fact that correlated well with immunohistochemical analysis of the same samples. The IHC results were confirmed by using a tissue microarray (TMA) containing 2,317 samples derived from 1,849 bladder cancer patients. Moreover, we found that the altered expression of A-FABP in invasive UCs is not due to deregulated expression of peroxisome proliferator-activated receptor gamma (PPARgamma), a trans-activator of A-FABP. Taken together, these results provide evidence that deregulation of A-FABP may play a role in bladder cancer progression and suggest that A-FABP could have a significant prognostic value in combination with other biomarkers.

Evaluation of the therapeutic potential of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib in preclinical models of bladder cancer

The epidermal growth factor receptor (EGFR) is associated with aggressive phenotypes and is an independent predictor of stage progression and mortality in bladder cancer. Gefitinib ('Iressa,' ZD1839) is an orally active EGFR-tyrosine kinase inhibitor. The objective of this study was to evaluate the in vitro and in vivo effects of gefitinib in the EGFR-expressing human bladder cancer cell lines 253J B-V, RT-112, and T24. EGFR expression was 3- and 2-fold higher in 253J B-V and RT-112, respectively, compared with T24 cells. Ten microm gefitinib inhibited EGFR, p42/44 extracellular signal-regulated kinase (ERK), and Akt/protein kinase B phosphorylation in all three of the cell lines. Inhibition of ERK by gefitinib was significantly greater in 253J B-V compared with RT-112 and T24 cells (9:2:1 in 253J B-V:RT-112:T24), whereas inhibition of Akt phosphorylation was less in 253J B-V compared with RT-112 and T24 cells (1:9:30 in 253J B-V:RT-112:T24). When cultured in serum-free medium supplemented with epidermal growth factor, 10 microm gefitinib inhibited DNA synthesis in T24 and RT-112 cells, whereas 1 microm gefitinib was sufficient to inhibit DNA synthesis in 253J B-V cells. Similarly, in the presence of serum, 10 microm gefitinib induced a significant reduction in S-phase and viable cell number in T24 and RT-112 cells, whereas 1-10 microm gefitinib caused a dose-dependent effect on these phenotypes in 253J B-V cells. Gefitinib significantly enhanced the ability of ionizing radiation to reduce colony forming ability in 253J B-V and RT-112 cells. In nude mice, a daily oral dose of 150 mg/kg gefitinib induced regression of tumors produced by 253J B-V cells growing at s.c. sites and suppression of tumors produced by these cells at orthotopic sites but had no effect on tumors produced by RT-112 cells growing at s.c. sites. The data indicates that gefitinib has potential therapeutic value, alone or in combination with ionizing radiation, in a subset of EGFR-expressing bladder cancers. However, there is a differential response to gefitinib in these EGFR-expressing bladder cancer cell lines. Although gefitinib can inhibit phosphorylation of EGFR, ERK, and Akt, and inhibit growth of bladder cancer cells in vitro, it does not necessarily inhibit growth of bladder cancer cells in vivo. It is likely that optimized therapy approaches will require an accurate "molecular" diagnosis allowing effective, selective, tailored therapeutic strategies to be designed.

Towards discovery-driven translational research in breast cancer

Discovery-driven translational research in breast cancer is moving steadily from the study of cell lines to the analysis of clinically relevant samples that, together with the ever increasing number of novel and powerful technologies available within genomics, proteomics and functional genomics, promise to have a major impact on the way breast cancer will be diagnosed, treated and monitored in the future. Here we present a brief report on long-term ongoing strategies at the Danish Centre for Translational Breast Cancer Research to search for markers for early detection and targets for therapeutic intervention, to identify signalling pathways affected in individual tumours, as well as to integrate multiplatform 'omic' data sets collected from tissue samples obtained from individual patients. The ultimate goal of this initiative is to coalesce knowledge-based complementary procedures into a systems biology approach to fight breast cancer.

Impact of proteomics on bladder cancer research

Detecting bladder cancer at an early stage and predicting how a tumor will behave and act in response to therapy, as well as the identification of new targets for therapeutic intervention, are among the main areas of research that will benefit from the current explosion in the number of powerful technologies emerging within proteomics. The purpose of this article is to briefly review what has been achieved to date using proteomic technologies and to bring forward novel strategies – based on the analysis of clinically relevant samples – that promise to accelerate the translation of basic discoveries into the daily clinical practice.

Combined chemotherapy and external beam radiotherapy for transitional cell carcinoma of the bladder

A growing body of evidence supports the treatment of invasive transitional cell carcinoma of the bladder with transurethral resection, chemotherapy, and external beam radiotherapy. Randomized trials have demonstrated the superiority of chemotherapy plus radiotherapy to radiotherapy alone. Several series with 10 years of follow-up demonstrate that the success of this approach can be maintained. Preservation of the urothelium, however, results in continued risk of de novo bladder cancer development in addition to the possibility of recurrence. Thus, continued close surveillance and treatment of subsequent superficial or invasive bladder cancer is an essential component of this bladder preservation approach. Concomitant cisplatin chemotherapy and radiotherapy or initial (neoadjuvant) combination cisplatin-based chemotherapy followed by radiotherapy are the two options best supported by the literature. How these regimens compare with each other and with cystectomy-based treatment remains to be defined.