Assessment of the efficacy of repeated instillations of mitomycin C mixed with a thermosensitive hydrogel in an orthotopic rat bladder cancer model.

BACKGROUND: We investigated a thermoreversible hydrogel that is highly viscous at body temperature, while fluid-like at a low temperature, thus aiming for a slow and prolonged intravesical drug release. Our study purposed to assess antitumor efficacy of mitomycin C (MMC) mixed with hydrogel in an orthotopic rat bladder cancer model. METHODS: Bladders of female Fischer F344 rats were grafted with 1.5 × 106 AY-27 urothelial carcinoma cells. On day 5, tumor presence was assessed by cystoscopy and rats were divided into six groups (five treatment, one control, n = 10/group). Intravesical treatments (0.5 mg or 1 mg MMC-H2O or MMC-hydrogel, or 2 mg MMC-hydrogel) were administered on days 5, 8 and 11. Rats were sacrificed at day 14 and bladders were evaluated. RESULTS: Rats with tumor at cystoscopy (47/60) were evaluated for efficacy. At necropsy, all control animals (8/8) had tumors. No microscopic tumors were present in the 0.5 mg and 1 mg MMC-hydrogel groups compared with 2/8 and 1/8 rats in the 0.5 mg and 1 mg MMC-H2O groups (p = 0.47 and p = 1.00, respectively).Greater toxicity was seen in animals treated with MMC-hydrogel compared with MMC-H2O, as demonstrated by lower body weights at necropsy (p = 0.000) and a tendency for more severe clinical signs in the 1 and 2 mg MMC-hydrogel groups. Rats that died prematurely received 1 mg (4/10) or 2 mg (9/10) of MMC-hydrogel. CONCLUSIONS: Under the current model conditions it is unclear whether instillation of MMC-hydrogel is more effective than MMC-H2O. Nonetheless, the observed difference in toxicity, acting as a surrogate marker for systemic MMC exposure in the MMC-hydrogel-treated rats, supports the prolonged drug release mechanism of the hydrogel.

Management of low-risk and intermediate-risk non-muscle-invasive bladder carcinoma.

Non-muscle-invasive bladder cancer is a highly recurrent disease. The health care costs for non-muscle-invasive bladder cancer are a major burden for society. Bladder cancer treatment starts with a presumed complete transurethral resection of a bladder tumor. Despite international guidelines for perioperative and/or adjuvant intravesical instillation therapy in non-muscle-invasive bladder cancer, adequate worldwide application is lacking. In patients who do get adjuvant intravesical instillations, recurrences are still frequent. New therapies in non-muscle-invasive bladder cancer are unsatisfactory and still experimental.

Urinary cytokines in patients treated with intravesical mitomycin-C with and without hyperthermia.

OBJECTIVES: To explore whether urinary cytokine and chemokine (CK) levels differed between cold mitomycin-C (cold-MMC)-treated patients and chemohyperthermia (C-HT)-treated patients, to shed light on the possible molecular mechanisms that might explain the superior outcome of C-HT. Furthermore, CK-differences were explored between C-HT responders and C-HT non-responders. METHODS: Twelve NMIBC patients were included. Nine received six-weekly C-HT, and three received four-weekly cold-MMC instillations. Urine was collected on 8-12 time points before and after every treatment. MDC, IL-2, IL-6, IL-8, IP-10, MCP-1 and RANTES were determined by Luminex(®)-analysis. RESULTS: Elevated urinary CK levels were observed in both groups after treatment. In general, CK-peaks were lower in the cold-MMC group in comparison with levels in the C-HT group. Significant higher MCP-1 and IL-6 levels were observed in C-HT-treated patients. Additionally, significant cumulative effects were observed for IP-10 and IL-2. However, IP-10 and IL-2 levels did not significantly differ between treatments. MDC levels after the first week of treatment were significantly higher in the C-HT responders compared with the non-responders. CONCLUSION: MMC treatment leads to elevated urinary CK levels with significantly higher MCP-1 and IL-6 levels in C-HT-treated patients. Increased MDC levels after the first C-HT instillation appear to be related to good clinical outcome and might be of additional value to personalize treatment. Studies involving more patients and longer follow-up are needed to substantiate this observation.

The effect of photochemical internalization of bleomycin in the treatment of urothelial carcinoma of the bladder: an in vitro study.

OBJECTIVES: In this in vitro study, we determined whether meso-tetraphenyl chlorin disulphonate (TPCS2a)-based photochemical delivery of bleomycin was able to potentiate the cytotoxicity of bleomycin on bladder cancer cells. MATERIALS AND METHODS: The human RT4, RT112, 253J, T24, and rat AY-27 urothelial carcinoma cell lines were used. Cells were seeded in 96-well plates. TPCS2a was added to the growth medium and the plates were incubated overnight. Cells were then resuspended in TPCS2a-free culture medium and incubated for 3 hours. Subsequently, cells were treated for 60 minutes with increasing doses of epirubicin, gemcitabine, mitomycin C, or bleomycin followed by illumination for different periods. Cell viability was measured with a colorimetric assay after 72 hours. RESULTS: For the single treatments, in all 5 cell lines a dose-dependent inhibition of cell proliferation was observed. This was seen both after treatment with TPCS2a-based photodynamic therapy (PDT), as well as after treatment with either bleomycin or one of the control chemotherapeutic agents. After treatment with PDT (240-s illumination), bleomycin 9.0 µM, and the combination of these treatments, relative survival percentages were 89.2 ± 13.0, 70.2 ± 8.9, and 30.5 ± 6.1, respectively, in the T24 cell line. After treatment with PDT (120-s illumination), bleomycin 27 µM and the combination of these treatments, relative survival percentages were 93.6 ± 15.7, 74.7 ± 9.6, and 30.0 ± 11.1, respectively, in the AY-27 cell line. In both cell lines, PDT combined with bleomycin showed significantly (P<0.001) higher cell kill than the sum of the single treatments, suggesting a photochemical internalization effect. CONCLUSIONS: TPCS2a-based photochemical internalization of bleomycin showed a significant, at least, additive antiproliferative activity against human and rat urothelial carcinoma cells in vitro. Thus, photochemical internalization may have therapeutic potential as an intravesical strategy against bladder cancer. As the effect is heterogeneous, biomarker studies are warranted to be able to predict the effects of a photochemical internalization-based treatment.

Results of a phase 1 dose escalation study of intravesical TMX-101 in patients with nonmuscle invasive bladder cancer.

PURPOSE: Imiquimod, a toll like receptor 7 (TLR-7) agonist, is effective as a topical treatment for skin malignancies. TMX-101 is a liquid formulation of imiquimod. In this study we establish a safety profile of TMX-101 in patients with nonmuscle invasive bladder cancer. MATERIALS AND METHODS: We conducted a multicenter phase 1 dose escalation study in patients with nonmuscle invasive bladder cancer. Patients were included in 1 of 4 dose groups (0.05%, 0.1%, 0.2% or 0.4%) and treated with 6 weekly instillations of TMX-101, starting 2 weeks after transurethral resection of bladder tumor. Patients were evaluated weekly, and pharmacokinetic and pharmacodynamic parameters were measured. RESULTS: A total of 16 patients were included in the study with 4 per dose group. Two patients dropped out after instillation 2 in dose groups 1 and 2. Overall, 88 instillations were administered without serious adverse events. There were 118 adverse events, of which 84 were related to the study drug. All adverse events were mild or moderate and number or severity was not correlated with dose group. Of the related adverse events 70% were confined to the genitourinary tract and resolved without intervention. There was a dose dependent systemic uptake with low plasma levels up to dose group 3 (0.2%, 100 mg). Maximum plasma concentration in dose group 4 (0.4%, 200 mg) was 71.7 ng/ml. This is below plasma concentrations of 123 and 128 ng/ml without significant side effects measured in healthy volunteers after subcutaneous (30 mg) or oral intake (100 mg) of imiquimod, respectively. CONCLUSIONS: Intravesical treatment with TMX-101 is safe. The side effects are common but mild and mostly limited to the genitourinary tract. There is a low systemic uptake.

Antitumor effects of cis-urocanic acid on experimental urothelial cell carcinoma of the bladder.

PURPOSE: We determined the effect of protodynamic therapy against bladder cancer cells in vitro and in vivo. We investigated cis-urocanic acid in rat bladder cancer cell cultures and in an orthotopic rat urothelial carcinoma model to assess its safety and antiproliferative activity. MATERIALS AND METHODS: The rat bladder cancer cell line AY-27 was exposed to cis-urocanic acid (BioCis Pharma, Turku, Finland) at pH 6.5 or 7.4 for 2 hours. Cell viability was measured by colorimetric assay at 24 and 48 hours. For in vivo experiments AY-27 cells were instilled into the acid treated bladder of 17 rats. After 4, 7 and 10 days 14 rats were treated intravesically with cis-urocanic acid 6% (weight per volume) or vehicle. Rats were sacrificed on day 12 and the bladders were dissected. Immunohistochemical staining was done to assess apoptosis (caspase-3) and cell proliferation (Ki-67) in vivo. RESULTS: Cis-urocanic acid caused dose dependent, pH dependent inhibition of AY-27 cell proliferation, showing the protodynamic action at concentrations of 0.5% and 1%. At higher cis-urocanic acid doses complete cell death was observed. All tumors detected in animals treated with vehicle were muscle invasive (stage T2 or greater) but only 43% of tumors were muscle invasive in the cis-urocanic acid treated group (p=0.049). There was no difference in the percent of apoptotic or proliferating tumor cells between treatment groups. No signs of toxicity were observed. CONCLUSIONS: Cis-urocanic acid showed direct antiproliferative activity against rat bladder cancer cells in vitro and antitumor effects in vivo. It may have therapeutic potential as an intravesical agent for nonmuscle invasive bladder cancer.

The orthotopic Fischer/AY-27 rat bladder urothelial cell carcinoma model to test the efficacy of different apaziquone formulations.

OBJECTIVES: Apaziquone used intravesically showed significant activity in phase I and II marker lesion studies in non-muscle-invasive bladder cancer. The objective of this study was to assess antitumor activity and safety of 3 different formulations of intravesical apaziquone in an orthotopic rat bladder cancer model. MATERIALS AND METHODS: Female Fischer F344 rats were instilled with 1.5 × 10(6) AY-27 urothelial cell carcinoma cells and divided in 3 treatment groups (n = 10) and 1 placebo group (n = 6). Intravesical treatment was administered for 1 hour on days 2 and 5. Rats were treated with apaziquone in the formulation used in phase I/II clinical trials (group 1); apaziquone with an altered buffering capacity being used in phase III clinical trials (group 2), and apaziquone as in group 2, but without propylene glycol in the diluent (group 3). On days 5 and 14, the bladder wall was inspected by cystoscopy and evaluated for macroscopic tumor growth. After sacrificing the rats (day 14), cystectomy was performed and the bladders were investigated. RESULTS: There were no signs of any toxicity due to the study drug. On histopathologic examination of the bladders 0, 1, and 2 tumors per group were found in group 1, 2, and 3, respectively. In the placebo-treated group, 60% of animals developed tumor, which is comparable to untreated animals. CONCLUSIONS: Apaziquone showed an excellent antitumor activity. The effectiveness of apaziquone in this orthotopic rat bladder tumor model corroborates the clinical observations and implies the validity of this model.

Pharmacokinetics and toxicity of intravesical TMX-101: a preclinical study in pigs.

OBJECTIVE: • To study the pharmacokinetic and toxicity profile of intravesically administered TMX-101, with its active ingredient R-837, a synthetic Toll-like receptor (TLR)-7 agonist, in a pig model. MATERIALS AND METHODS: • TLR-7 expression was determined by immunohistochemistry in human and pig bladder tissue. • Four groups of six pigs received a 1-h intravesical instillation with R-837 of different formulations. • Pharmacokinetic analysis was performed on plasma. Toxicity evaluation included monitoring the well-being of the animals, peripheral blood cell counts, and interleukin-6 and creatinine measurements. Urine was collected for R-837 measurement and dipstick analysis. • In total, three pigs per group were sacrificed 24 h post-treatment, and the remaining animals were sacrificed after 1 week. Histopathological examination of the bladder wall was performed. RESULTS: • TLR-7 was homogeneously expressed in human and pig urothelium. • R-837 and vehicle were well tolerated without deterioration in animal well-being. • Systemic R-837 absorption was low. • Mean maximum plasma concentration of R-837 differed depending on the formulation. Post-treatment, plasma levels were negligible at 24 h. • Histopathological examination of the bladders did not show significant abnormalities, apart from the intended inflammatory reaction in the R-837 treated groups. CONCLUSION: • Intravesically administered R-837 in pigs, which showed a similar TLR-7 distribution in bladder tissue as humans, is well tolerated and causes no bladder wall toxicity, and formulations with poloxamer and hydroxypropyl-ß-cyclodextrin showed less systemic absorption.

Hexaminolevulinate-guided fluorescence cystoscopy in the diagnosis and follow-up of patients with non-muscle-invasive bladder cancer: review of the evidence and recommendations.

CONTEXT: Compared with standard white-light cystoscopy, photodynamic diagnosis with blue light and the photosensitiser hexaminolevulinate has been shown to improve the visualisation of bladder tumours, reduce residual tumour rates by at least 20%, and improve recurrence-free survival. There is currently no overall European consensus outlining specifically where hexaminolevulinate is or is not indicated. OBJECTIVE: Our aim was to define specific indications for hexaminolevulinate-guided fluorescence cystoscopy in the diagnosis and management of non-muscle-invasive bladder cancer (NMIBC). EVIDENCE ACQUISITION: A European expert panel was convened to review the evidence for hexaminolevulinate-guided fluorescence cystoscopy in the diagnosis and management of NMIBC (identified through a PubMed MESH search) and available guidelines from across Europe. On the basis of this information and drawing on the extensive clinical experience of the panel, specific indications for the technique were then identified through discussion. EVIDENCE SYNTHESIS: The panel recommends that hexaminolevulinate-guided fluorescence cystoscopy be used to aid diagnosis at initial transurethral resection following suspicion of bladder cancer and in patients with positive urine cytology but negative white-light cystoscopy for the assessment of tumour recurrences in patients not previously assessed with hexaminolevulinate, in the initial follow-up of patients with carcinoma in situ (CIS) or multifocal tumours, and as a teaching tool. The panel does not currently recommend the use of hexaminolevulinate-guided fluorescence cystoscopy in patients for whom cystectomy is indicated or for use in the outpatient setting with flexible cystoscopy. CONCLUSIONS: Evidence is available to support the use of hexaminolevulinate-guided fluorescence cystoscopy in a range of indications, as endorsed by an expert panel.

Experimental rat bladder urothelial cell carcinoma models.

Bladder cancer is a major public health problem. Currently available therapeutic options seem to be unable to prevent bladder cancer recurrence and progression. To enable preclinical testing of new intravesical therapeutic agents, a suitable bladder tumor model that resembles human disease is highly desirable. The aim of this topic paper was to discuss the problems associated with current in vivo animal bladder tumor models, focusing on the orthotopic syngeneic rat bladder tumor model. In the second part of the paper the development of a potential new orthotopic rat bladder tumor model is described.

Fluorescence in situ hybridization: a multitarget approach in diagnosis and management of urothelial cancer.

Noninvasive tests for detecting genetic or molecular alterations in urine indicative of urothelial cancer are increasingly becoming the focus of urological cancer research. Since its approval by the US FDA in 2001, the fluorescence in situ hybridization test (Vysis UroVysion) has been widely evaluated. In general, published data demonstrate better sensitivity and equal or better specificity compared with routine cytology, which is still considered the 'gold standard' in diagnosing and monitoring bladder tumors. However, the fluorescence in situ hybridization test seems to provide not only a useful tool in bladder cancer detection, but also in the diagnosis of upper urinary tract tumors, surveillance and determining therapy effectiveness. This multitarget assay that detects four different chromosomal aberrations in tumor cells is a kind of objective molecular cytology and has proven advantages over routinely used cytology.