Tyrosine kinase inhibitors of the epidermal growth factor receptor as adjuncts to systemic chemotherapy for muscle-invasive bladder cancer

Regorefenib induces extrinsic/intrinsic apoptosis and inhibits MAPK/NF-κB-modulated tumor progression in bladder cancer in vitro and in vivo

The aim of the present study is to investigate anticancer effect and mechanism of regorafenib in bladder cancer in vitro and in vivo. Human bladder cancer TSGH 8301 cells were treated with regorafenib, NF-κB, AKT, or mitogen-activated protein kinase (MAPK) inhibitors for different time. The changes of cell viability, NF-κB activation, apoptotic signaling transduction, and expression of tumor progression-associated proteins were evaluated with MTT, NF-κB reporter gene assay, flow cytometry, and Western blotting assay. TSGH 8301 tumor bearing mice were established and treated with vehicle (140 μL of 0.1% DMSO) or regorafenib (10 mg/kg/day by gavage) for 15 days. The changes of tumor volume, body weight, NF-κB activation, MAPK activation, and tumor progression-associated proteins (MMP-9, XIAP, VEGF, and Cyclin-D1) after regorafenib treatment were evaluated with digital caliper, digital weight, and ex vivo Western blotting assay. Our results demonstrated NF-κB activation and protein levels of MMP-9, XIAP, VEGF, and Cyclin-D1 were significantly reduced by NF-κB (QNZ), ERK (PD98059), and P38 (SB203580) inhibitors. Regorafenib also significantly induced extrinsic and intrinsic apoptotic signaling transduction in bladder cancer in vitro. In addition, regorafenib significantly inhibited tumor growth, NF-κB, p38, ERK activation and expression of tumor progression-associated proteins in bladder cancer in vitro and in vivo. Taken together, these results proved that regorafenib not only induced apoptosis through extrinsic and intrinsic pathways and but suppressed MAPK/ NF-κB-modulated tumor progression in bladder cancer.

Epidermal Growth Factor Receptor and Ki-67 as Predictive Biomarkers Identify Patients Who Will Be More Sensitive to Intravesical Instillations for the Prevention of Bladder Cancer Recurrence after Radical Nephroureterectomy

BACKGROUND

To date, prophylactic intravesical chemotherapy after radical nephroureterectomy is one of the few available treatments that effectively prevent secondary bladder cancer. However, treating all patients with prophylactic intravesical chemotherapy is excessive for patients who are at a low risk or insensitive to the treatment. Thus, to guide individualized clinical treatment, in addition to identifying patients who are at risk of bladder cancer recurrence, it is equally necessary to identify the patients who will benefit the most from prophylactic, postoperative intravesical instillation therapy.

METHODS

Epidermal growth factor receptor (EGFR) and Ki-67 expression levels were measured using immunohistochemical staining samples from 320 patients with upper urinary tract urothelial carcinoma (UTUC) from 2004 to 2012. Although no patients received intravesical chemotherapy after RNU before 2008, this method began to be used in 2008 to prevent bladder cancer recurrence. To identify the patients who would most benefit from intravesical chemotherapy, we assessed biological interactions between intravesical chemotherapy and clinicopathological factors or biomarkers.

RESULTS

The incidence rates of bladder UTUC recurrence decreased after intravesical chemotherapy, and the decrease was greater in patients with low Ki-67 levels, negative EGFR staining and preoperative positive urine cytology. Biological interactions were observed between intravesical chemotherapy, low-level Ki-67 and EGFR negativity. The multivariate analysis showed that after balancing a variety of factors, intravesical chemotherapy is a protective factor for preventing intravesical recurrence in the negative EGFR, low-level Ki-67 and preoperative positive urine cytology sub-groups but not in their corresponding sub-groups. Additionally, the multivariate analysis revealed that preoperative positive urine cytology and Ki-67 were not but that EGFR positivity was an independent risk factor for recurrence after intravesical chemotherapy.

CONCLUSIONS

Patients with low Ki-67 levels, negative EGFR staining and preoperative positive urine cytology appear to be more sensitive to intravesical instillations for bladder recurrence prevention after RNU.

Biomarker in Cisplatin-Based Chemotherapy for Urinary Bladder Cancer

The treatment of metastasized bladder cancer has been evolving during recent years. Cisplatin based chemotherapy combinations are still gold standard in the treatment of advanced and metastasized bladder cancer. But new therapies are approaching. Based to this fact biological markers will become more important for decisions in bladder cancer treatment. A systematic MEDLINE search of the key words "cisplatin", "bladder cancer", "DNA marker", "protein marker", "methylation biomarker", "predictive marker", "prognostic marker" has been made. This review aims to highlight the most relevant clinical and experimental studies investigating markers for metastasized transitional carcinoma of the urothelium treated by cisplatin based regimens.

Targeted agents in second-line bladder cancer therapy

The treatment of metastasized urothelial cancer has been evolving in recent years. In particular, in the second-line setting after the failure of platinum-containing therapy, options are few and besides vinflunine, the recently approved standard in Europe, well-designed highly selective clinical trials may be possible alternatives for patients in this palliative situation. However, targeted therapy approaches have not achieved the same results in urothelial cancer as for instance in renal cell carcinoma. Many of the new targeted drugs have been investigated as single agents in phase II clinical trials without convincing oncologic outcome. This review aims to highlight the most relevant clinical studies examining targeted agents in the second-line setting of metastasized transitional carcinoma of the urothelium.

Imatinib radiosensitizes bladder cancer by targeting homologous recombination

Radiotherapy is a major treatment modality used to treat muscle-invasive bladder cancer, with patient outcomes similar to surgery. However, radioresistance is a significant factor in treatment failure. Cell-free extracts of muscle-invasive bladder tumors are defective in nonhomologous end-joining (NHEJ), and this phenotype may be used clinically by combining radiotherapy with a radiosensitizing drug that targets homologous recombination, thereby sparing normal tissues with intact NHEJ. The response of the homologous recombination protein RAD51 to radiation is inhibited by the small-molecule tyrosine kinase inhibitor imatinib. Stable RT112 bladder cancer Ku knockdown (Ku80KD) cells were generated using short hairpin RNA technology to mimic the invasive tumor phenotype and also RAD51 knockdown (RAD51KD) cells to show imatinib's pathway selectivity. Ku80KD, RAD51KD, nonsilencing vector control, and parental RT112 cells were treated with radiation in combination with either imatinib or lapatinib, which inhibits NHEJ and cell survival assessed by clonogenic assay. Drug doses were chosen at approximately IC40 and IC10 (nontoxic) levels. Imatinib radiosensitized Ku80KD cells to a greater extent than RAD51KD or RT112 cells. In contrast, lapatinib radiosensitized RAD51KD and RT112 cells but not Ku80KD cells. Taken together, our findings suggest a new application for imatinib in concurrent use with radiotherapy to treat muscle-invasive bladder cancer. Cancer Res; 73(5); 1611-20. ©2012 AACR.

EGFR expression in urothelial carcinoma of the upper urinary tract is associated with disease progression and metaplastic morphology

EGFR represents a promising therapeutic target in urothelial cancer (UC). Our study aimed to investigate the clinicopathological significance of EGFR in upper urinary tract UC. EGFR was immunohistochemically assessed (EGFR pharmDX kit(TM)) in 268 consecutive tumours using a tissue microarray technique and correlated with other histopathological parameters as well as patient outcome. EGFR immunoreactivity was observed in 140/253 (55%) evaluable UCs and was associated with high tumour stage (47% pTa/pT1 vs 66% pT2-pT4; p=0.003) and high tumour grade (45% low grade vs 67% high grade; p<0.001). In addition, EGFR expression was associated with metaplastic squamous and/or glandular differentiation (p<0.001). EGFR staining intensity was 1+ in 49%, 2+ in 31%, and 3+ in 20% of cases. EGFR 3+ staining intensity was associated with the occurrence of metastatic disease by univariate analysis (p=0.016). Multivariate analysis, however, proved only pT stage >1 (p<0.001) and high tumour grade (p<0.001) to be independent predictors of patient outcome. In conclusion, EGFR was significantly associated with advanced disease and metaplastic squamous and/or glandular differentiation. Since UCs with metaplastic morphology have been shown to be more resistant to conventional radiotherapy or chemotherapy, the strikingly strong EGFR expression in these tumours may offer a new perspective for affected patients.

Erlotinib (OSI-774)-induced inhibition of transitional cell carcinoma of bladder cell line growth is enhanced by interferon-?

OBJECTIVE

To examine whether erlotinib gives similar results to gefitinib, a small molecule epidermal growth factor receptor (HER1/EGFR) tyrosine kinase (TK) inhibitor that inhibits the growth of human bladder cancer cell lines in vitro, and given that interferon-alpha (IFNalpha) promotes an antiproliferative effect of HER1/EGFR inhibitors on colon cancer cell lines, to also determine the effects of erlotinib alone or together with INFalpha on bladder cancer cell lines, and whether sensitivity is influenced by HER1/EGFR mutation status.

MATERIALS AND METHODS

Seven bladder cancer cell lines were characterized for HER1/EGFR expression, then treated with erlotinib alone, IFNalpha alone, or IFNalpha plus erlotinib. Cell growth inhibition was assessed by crystal-violet staining and HER1/EGFR expression by flow cytometry. Synergy was evaluated using the combination index of Chou and Talalay. DNA from these cell lines in the linear growth phase and from 14 bladder cancer tissue samples were tested for HER1/EGFRTK mutations.

RESULTS

Cell-surface HER1/EGFR expression was present in all seven bladder cancer cell lines. Both erlotinib and IFNalpha independently were significantly antiproliferative, and combined treatment synergistically enhanced the sensitivity in six of the seven cell lines. No bladder cancer cell lines or tissues tested expressed HER1/EGFRTK mutations.

CONCLUSION

Erlotinib inhibits the growth of human bladder cancer cell lines. Enhanced inhibition in the presence of IFNalpha is not determined by the presence of HER1/EGFRTK mutations. This study might have clinical implications for improving the treatment of bladder cancer.

Novel HER2 selective tyrosine kinase inhibitor, TAK-165, inhibits bladder, kidney and androgen-independent prostate cancer in vitro and in vivo

PURPOSE

TAK-165 is a new potent inhibitor of human epidermal growth factor receptor 2 (HER2) tyrosine kinase. Several reports suggest HER2 expression in bladder cancer, renal cell carcinoma (RCC) and androgen-independent prostate cancer. We therefore investigated the antitumor effect of TAK-165 on these urological cancer cells.

MATERIALS AND METHODS

Western blot analysis was performed to confirm HER2 expression in cell lines. To study in vitro efficacy, cells were treated with TAK-165 at various concentrations for 72 h and then counted using a hemocytometer. Then the IC50 value was calculated. In the xenograft model, after the tumor reached 200-300 mm3 in volume, mice were orally administered TAK-165 10 mg/kg per day or 20 mg/kg per day or saline for 14 consecutive days (n=6-8).

RESULTS

HER2 expression was observed in HT1376, UMUC3, T24 (bladder), ACHN (kidney), DU145, LNCaP, LN-REC4 (prostate), although the expression level in these cells was weak compared with BT474 (a breast cancer cell line which expresses HER2 strongly). IC50 was varied from 0.09 to greater than 25 micromol/L in the bladder cancer cell line. ACHN cells were less sensitive in vitro. The prostate cancer cell lines studied were all sensitive (IC50 0.053-4.62 micromol/L). In the xenograft model, treatment with TAK-165 significantly inhibited growth of UMUC-3, ACHN, and LN-REC4. The antitumor effect (T/C [%]=growth of TAK-165 treated tumor/average growth of control tumorx100) after 14 days treatment were 22.9%, 26.0%, and 26.5% in UMUC3, ACHN and LN-REC4, respectively.

CONCLUSIONS

TAK-165 may be a hopeful new agent for bladder, kidney and androgen-independent prostate cancer.

Phase II Study of Pemetrexed for Second-Line Treatment of Transitional Cell Cancer of the Urothelium

Purpose

To assess the antitumor activity and toxicity of pemetrexed as second-line chemotherapy in patients with locally advanced or metastatic transitional cell carcinoma (TCC) of the urothelium.

Patients and Methods

Eligible patients had a performance status of 0 or 1, adequate organ function, previous treatment with one prior chemotherapy regimen for locally advanced or metastatic TCC of the urothelium or relapsed within 1 year of adjuvant or neoadjuvant treatment. Patients received pemetrexed 500 mg/m2 intravenously on day 1 every 21 days, with vitamin B12, folic acid, and dexamethasone prophylaxis.

Results

Forty-seven patients were enrolled and included in the intent-to-treat efficacy analysis. Responses: 3 (6.4%) complete responses and 10 (21.3%) partial responses produced an overall response rate of 27.7%. Ten patients (21.3%) had stable disease and 22 patients (46.8%) progressed. The median time to progressive disease was 2.9 months (95% CI, 1.7 months to 4.6 months) and median overall survival was 9.6 months (95% CI, 5.1 months to 14.6 months). Median duration of response was 5.0 months (95% CI, 3.9 months to 13.8 months). Of the 47 patients assessable for safety, grade 3 or 4 hematologic events were thrombocytopenia (8.5%; 0.0%), neutropenia (4.3%; 4.3%) and anemia (2.1%; 2.1%), respectively. Nonlaboratory toxicities included grade 4 stomatitis/pharyngitis, sepsis syndrome (one patient each), and grade 3 fatigue (three patients) and diarrhea (two patients).

Conclusion

Single-agent pemetrexed is safe and active as second-line treatment of patients with advanced TCC of the urothelium. Additional evaluation in the first- or second-line setting in TCC of the urothelium is warranted.

Genetic alterations in urothelial bladder carcinoma: an updated review

New oncogenes and tumor suppressor genes that play an important role in the pathogenesis of urothelial bladder carcinoma have been discovered. The objectives of this review were to summarize the most important oncogenes and tumor suppressor genes involved in urothelial carcinoma and to address their role in pathogenesis, their prognostic value, and their potential use as therapeutic targets. The collected data led the authors to propose a common pathway in which the fibroblastic growth factor receptor 3 (FGFR3) mutation seems to be the earliest genetic abnormality responsible for the transformation from normal tissue to atypia and dysplasia. Three different progression pathways were proposed: The first operative pathway is from dysplasia to superficial papillary pathologic Ta (pTa) tumors to pT1 tumors and, ultimately, to pT2 tumors with FGFR3 and tuberous sclerosis complex 1 (TSC1) the responsible genes. The second major operative pathway is from dysplasia, to carcinoma in situ, and to solid pT1 and pT2 tumors. The third pathway of progression is from dysplasia to papillary T1 and pT2 tumors. The genes involved in the last 2 pathways are the p53, serine threonine protein kinase 15 (STK15), triple-function domain (TRIO), fragile histidine triad (FHIT), p63 genes; and alterations of 20q and 5p, alterations of adhesions, angiogenesis, and matrix-remodeling gene products also are involved. Finally, murine leukemia viral oncogene homologue 1 (RAF1) and CD9 are involved in the progression from papillary pT1 tumors to pT2 tumors.

Neo-adjuvant chemotherapy for muscle-invasive bladder cancer: a look ahead

Randomized clinical trials of neo-adjuvant cisplatin-based combination chemotherapy for locally advanced muscle invasive bladder cancer has shown a survival benefit over cystectomy alone. Pathologic complete response (pT0) after neo-adjuvant chemotherapy is emerging as a potentially important surrogate clinical end point. Future clinical trials incorporating targeted therapies with novel clinical end points may accelerate development of therapeutic strategies for locally advanced muscle invasive bladder cancer. Furthermore, evaluation of molecular markers may further help to stratify patients to a risk adapted approach.

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.

Clinical applications for targeted therapy in bladder cancer

The tremendous amount of data accumulated through genomics, proteomics, and metabolomic technologies has not led to a definitive understanding of the mechanisms underlying cancer. The challenge remains as to how to integrate all of the relevant knowledge and data in a systematic manner so that researchers can gain the knowledge needed to devise the best therapeutic and diagnostic strategies. Human transitional cell carcinoma of the bladder is genetically heterogeneous, and it is surrounded by a complex tissue microenvironment involving vasculature, stromal cells, and connective tissue. One of the most challenging problems facing cancer researchers is the lack of correlation between in vitro cell lines and animal tumor models and human in vivo tumors. A few promising approaches are being devised that will help address this issue in the coming years. One such approach is the measurements of molecular levels of receptors, ligands, pathways components, and so on, directly in human tumors through in vivo imaging, or through proteomic profiling, as it has been proposed as standard protocol for cancer diagnostics and therapeutics.

Molecular markers for predicting recurrence, progression and outcomes of bladder cancer (do the poster boys need new posters?)

PURPOSE OF REVIEW

Molecular markers for bladder cancer recurrence and progression continue to drive many research programmes. Translating the laboratory findings into the clinical environment where these markers are used in clinical decision making has proved problematic. In the clinical arena, stage and grade are still the main focus for decisions about patient management. There is however an evolution in bladder cancer research from single-marker/single-pathway research to a more global assessment of the tumour cell with DNA microarrays and proteomics.

RECENT FINDINGS

In the last year, DNA microarray assessment has revealed several interesting molecular markers such as p33ING1 and DEK. Parallel "conventional" single-pathway research has focused on new novel markers such as HER2/neu, survivin and matrix metalloproteinase 2 (MMP-2). Molecular markers that have a long-standing association with bladder cancer progression such as p53, E-cadherin and Ki-67 have been reviewed by both single-marker studies and by microarray studies and their status remains important.

SUMMARY

It is an exciting time in the molecular biology research of bladder cancer as the focus changes to assess the global genetic and protein expression within tumour cells. From such a wealth of information it is likely that molecular markers will make the translation from benchside to bedside.