Animal Model Of Bladder Cancer Research Articles

Structural insights into a functional unit from an immunogenic mollusk hemocyanin

Mollusk hemocyanins, among the largest known proteins, are used as immunostimulants in biomedical and clinical applications. The hemocyanin of the Chilean gastropod Concholepas concholepas (CCH) exhibits unique properties, which makes it safe and effective for human immunotherapy, as observed in animal models of bladder cancer and melanoma, and dendritical cell vaccine trials. Despite its potential, the structure and amino acid sequence of CCH remain unknown. This study reports two sequence fragments of CCH, representing three complete functional units (FUs). We also determined the high-resolution (1.5Å) X-ray crystal structure of an "FU-g type" from the CCHB subunit. This structure enables in-depth analysis of chemical interactions at the copper-binding center and unveils an unusual, truncated N-glycosylation pattern. These features are linked to eliciting more robust immunological responses in animals, offering insights into CCH's enhanced immunostimulatory properties and opening new avenues for its potential applications in biomedical research and therapies.

Stool Microbiome Signature Associated with Response to Neoadjuvant Pembrolizumab in Patients with Muscle-invasive Bladder Cancer

Neoadjuvant pembrolizumab has been shown to be a valid treatment for patients affected by muscle-invasive bladder cancer (MIBC), as demonstrated in the PURE-01 clinical trial (NCT02736266). Among the tumor-extrinsic factors influencing immunotherapy efficacy, extensive data highlighted that the microbiome is a central player in immune-mediated anticancer activity. This report aimed to investigate the composition and role of stool microbiome in patients enrolled in the PURE-01 clinical trial. An orthotopic animal model of bladder cancer (MB49-Luc) was used to support some of the findings from human data. An analysis of stool microbiome before pembrolizumab was conducted for 42 patients, of whom 23 showed a pathologic response. The information in the preclinical model of orthotopic bladder cancer treated with anti–PD-1 antibody or control isotype was validated. Linear discriminant analysis effect size and linear models were used to identify the bacterial taxa enriched in either responders or nonresponders. The identified taxa were also tested for their association with event-free survival (EFS). Survival at 31 d after tumor instillation was used as the study endpoint in the preclinical model. Responders and nonresponders emerged to differ in terms of enrichment for 16 bacterial taxa. Of these, the genus Sutterella was enriched in responders, while the species Ruminococcus bromii was enriched in nonresponders. The negative impact of R. bromii on anti–PD-1 antibody activity was also observed in the preclinical model. EFS and survival of the preclinical model showed a negative role of R. bromii. We found different stool bacterial taxa associated with the response or lack of response to neoadjuvant pembrolizumab. Moreover, we provided experimental data about the negative role of R. bromii on immunotherapy response. Further studies are needed to externally validate our findings and provide mechanistic insights about the host-pathogen interactions in MIBC. Patient summaryUsing prepembrolizumab stool samples collected from patients enrolled in the PURE-01 clinical trials, we identified some bacterial taxa that were enriched in patients who either responded or did not respond to immunotherapy. Using an animal model of bladder cancer, we gathered further evidence of the negative impact of the Ruminococcus bromii on immunotherapy efficacy. Further studies are needed to confirm the current findings and test the utility of these bacteria as predictive markers of immunotherapy response.

Enhanced urease-driven nanobots for radionuclide-based bladder cancer therapy

Bladder cancer treatment with intravenous medication delivery has reasonable survival rates but modest therapeutic efficacy. Taking advantage of their superior diffusion and mixing capacities in urine compared to traditional pharmaceuticals or passive nanoparticles, self-propelled nanoparticles, also known as nanobots, have been proposed as a solution to the latter issue. Nonetheless, nothing is known about how well nanobots can translate into bladder cancer treatments. Here, urease-powered, radiolabelled mesoporous silica-based nanobots were evaluated in an orthotopic animal model of bladder cancer. Both in vivo and ex vivo findings showed increased accumulation of nanobots at the tumor location; positron emission tomography in vivo showed an eight-fold increase. The ex vivo tumor penetration by nanobots was validated by label-free optical contrast based on polarization-dependent scattered light-sheet microscopy of cleared bladders. Intravesically treatment was given to tumor-bearing mice. About 90% less tumor size was observed when radio-iodinated nanobots were used for radionuclide therapy, establishing nanobots as effective delivery nanosystems for bladder cancer treatment.

Melatonin Inhibits EMT in Bladder Cancer by Targeting Autophagy.

Melatonin, a naturally biosynthesized molecule secreted by the pineal gland, exhibits antitumor activities against several different types of cancer. The mechanisms of action of melatonin against tumor progression involve cellular apoptosis, antimetastatic activity, antioxidant and mutagenic effects, antiangiogenic activity, and the restoration of cancer immune surveillance. Melatonin has anticancer activity when administered alone or in combination with standard chemotherapeutic agents, with measurable improvements seen in the clinical endpoints of tumor regression and patient survival. However, scant clinical evidence supports the use of melatonin in bladder cancer treatment. Our study has found that melatonin treatment suppresses the bladder cancer cell migratory ability by inhibiting the epithelial-mesenchymal transition (EMT) process, which appears to be linked to melatonin-induced decreases in bladder cancer cell autophagy. Finally, an evaluation of in vivo melatonin-induced antitumor effects in an orthotopic animal model of bladder cancer indicated that melatonin treatment slightly prolonged the survival of tumor-bearing mice. Our study offers novel insights into the use of melatonin in bladder cancer treatment.

A Multilayer Nanofibrous Mat for the Topical Chemotherapy of the Positive Margin in Bladder Cancer.

Treatment of positive margins after solid tumor resection remains a significant challenge for clinicians. Owing to unique structural features, electrospun nanofibrous mats are promised to be an implantable antitumor system through the delivery of active agents in a controlled manner. In this study, we utilized sequential electrospinning to fabricate a multilayer mat in which gemcitabine (GEM) and cisplatin (CDDP) were electrospun individually in distinct layers. By designing the structure, the multilayer mat could deliver antitumor agents sustainedly and prolong the release of GEM, which is loaded in the inner layer. In vitro assays show that the multilayer mats effectively inhibit bladder cancer (BC) cells and elevate apoptosis. In animal models of BC, the implantable drug-loaded fibrous mat can effectively treat positive margins and prevent local recurrence. Moreover, the local delivery of GEM and CDDP significantly lowers liver toxicity compared with systemic chemotherapy. In summary, a multilayer nanofibrous mat is developed for the localized and controlled delivery of GEM, dramatically improving the treatment of residual tumors and preventing BC recurrence. Impact statement The designed multilayer nanofibrous mats can achieve two chemotherapeutic drugs (gemcitabine and cisplatin) co-loading and time-programmed sustained release, significantly improving our previous study. The antitumor effect of the drug-loaded mat in vivo and in vitro was sufficiently demonstrated. We expect to bring a new strategy of topical chemotherapy for treating positive surgical margins in bladder cancer.

Lamprey immunity protein enables detection for bladder cancer through recognizing N-hydroxyacetylneuraminic acid (Neu5Gc)-modified as a diagnostic marker and exploration of its production mechanism

Previous studies have demonstrated that Neu5Gc is highly expressed in breast, ovarian, prostate, colon and lung cancers, but not in normal human cells. The presence of Neu5Gc is important for prognosis and is associated with aggressiveness, metastasis, and tumor grade. However, increased Neu5Gc in bladder cancer remains unclear. LIP from lamprey binds the carbohydrate receptor of N-glycolylneuraminic acid (Neu5Gc). The combination of Neu5Gc and LIP suggested that it might be used as a diagnostic tool for the detection of Neu5Gc tumor antigen. Here, the classical animal model of bladder cancer was successfully induced by MNU bladder perfusion. The ELISA results showed that the expression level of Neu5Gc in the urine of normal rats was 94.96 ± 21.01ng/mg, and that of bladder cancer rats was 158.28 ± 34.86 ng/mg. In addition, the results of SNA and LIP immunohistochemistry demonstrated the high expression of Neu5Gc in bladder cancer. After the addition of Neu5Gc to BIU-87 and SV-HUC-1 cells, transcriptomic sequencing and real-time quantitative PCR analysis demonstrated that the gene expression of Neu5Gc synthesis pathway was significantly increased. These data suggest that LIP provides a new tool for the detection of biological samples, especially urine from patients with bladder cancer or suspected cancer, and that revealing the mechanism of abnormal glycosylation can provide theoretical basis for clinical studies.

Animal Models in Bladder Cancer.

Background: Bladder cancer (urothelial cancer of the bladder) is the most common malignancy affecting the urinary system with an increasing incidence and mortality. Mouse models of bladder cancer should possess a high value of reproducibility, predictability, and translatability to allow mechanistic, chemo-preventive, and therapeutic studies that can be furthered into human clinical trials. Objectives: To provide an overview and resources on the origin, molecular and pathological characteristics of commonly used animal models in bladder cancer. Methods: A PubMed and Web of Science search was performed for relevant articles published between 1980 and 2021 using words such as: “bladder” and/or “urothelial carcinoma” and animal models. Animal models of bladder cancer can be categorized as autochthonous (spontaneous) and non-autochthonous (transplantable). The first are either chemically induced models or genetically engineered models. The transplantable models can be further subclassified as syngeneic (murine bladder cancer cells implanted into immunocompetent or transgenic mice) and xenografts (human bladder cancer cells implanted into immune-deficient mice). These models can be further divided—based on the site of the tumor—as orthotopic (tumor growth occurs within the bladder) and heterotopic (tumor growth occurs outside of the bladder).

A candidate antineoplastic herbal agent for bladder cancer: Ankaferd Blood Stopper.

Ankaferd Blood Stopper (ABS) was used for in vitro studies of osteosarcoma and colon carcinoma cancer cell lines to reveal the apoptotic and antineoplastic effects. The aim of this study is to evaluate the antineoplastic effect of ABS on bladder cancer cell cultures. We prospectively collected minimum 0.5cm parts of fresh frozen tumour samples from patients with bladder tumour from 2015 to 2017. Primary bladder cancer cultures were produced from the frozen tumour samples. Two different doses of ABS were used on cancer cell cultures. Viability tests of each cell cultures were performed. Flow cytometry was used for the determination of apoptosis and necroptosis. We also checked the effect of ABS on different stages, grade and variant histology of bladder cancer cells. The results of all cancer cell cultures were compared with their own controls. This study included 24 patients. Mean age of patients was 66.2±11.7years (34-83years), where 19 of them (79.5%) were males and five (20.5%) were females. When we compared the data, we found decreased cancer cell viability ratio in each ABS group compared with their own controls. Necroptosis was observed in the great majority of ABS groups, and necroptosis and apoptosis were observed in some cell cultures. In this study, we demonstrated the cytotoxic effect of ABS on bladder cancer cells. The results of this study suggests planning of animal model of bladder cancer for ABS with intravesical application as an antineoplastic agent. In the future, ABS may be a candidate intravesical treatment agent for bladder cancer.

Abstract 2912: Changes in mouse bladder cancer microbiome associated with exposure to bladder carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine

Abstract Background: BBN (N-butyl-N-(4-hydroxybuytl) nitrosamine) is the most commonly employed carcinogen in the classical animal model of bladder cancer based on chemical carcinogenesis of the bladder urothelium. BBN closely recapitulates the histological and genetic characteristics of human bladder cancer and conceptually simulates tobacco exposure as the leading cause of bladder cancer. Little is known about microbial changes that occur during bladder carcinogenesis, but the microbiome is increasingly recognized as an important dimension in both carcinogenesis and cancer treatment. We hypothesized that the bladder tissue microbiome would become altered during the course of BBN carcinogenesis and sought to annotate these changes using 16S metagenomics. Methods: Starting at 8-12 weeks of age, male (N=33) and female (N=22) C57BL/6 mice were administered 0.05% BBN in drinking water for 12 weeks then switched to regular water. Control mice drank regular water. Bladder was collected pre-exposure, after 6 and 12 weeks of exposure, and at the time of tumor identification (tumors typically detectable between 14-22 weeks from start of treatment using this model). DNA extracted from the bladders was subjected to PCR amplification using primers for the V3-V4 regions of the bacterial 16S rRNA. Results: Bladder tissue 16S rRNA deep sequencing revealed significant differences in alpha-diversity metrics between the BBN and control groups at 12 weeks including PD_whole_tree, observed species, Fisher's alpha and Margalef indices (p<0.05 for all). BBN treatment appeared to lower bacterial diversity in the bladder. The alpha-diversity scores remained significantly reduced at the time of bladder tumor harvest in the BBN group (p<0.05). Verrucomicrobia was identified as the most abundant phylum across BBN-administered groups. Akkermansia, Clostridium XI, and Veillonella were the most enriched genera identified in the BBN mice. The mucin-degrading bacterial species Akkermansia muciniphila began to be enriched in the BBN group starting at 6 weeks of treatment (control v BBN, p=0.05). Functional assessment of the microbiome using PICRUSt revealed significant upregulation of genes belonging to the pathways related to flagellar assembly and bacterial motility, which could facilitate tumor colonization through intracellular accumulation, and intratumoral motility. Interestingly, coincident with the cessation of BBN treatment at 12 weeks, the differences between the BBN and control groups began to be less pronounced at later time points than those seen at 6 weeks, suggesting a restoration of microbial community upon BBN removal despite the carcinogenesis cascade having started. Conclusions: Pronounced microbial changes occur within the bladder and bladder tumors induced by BBN in the murine model. This annotation lays the groundwork for potential therapeutic manipulations. Citation Format: Rashida Ginwala, Jodie Franklin, James R. White, Uttam Satyal, Abhishek Srivastava, Philip H. Abbosh. Changes in mouse bladder cancer microbiome associated with exposure to bladder carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2912.

Perspective: Humanized Pig Models of Bladder Cancer

Bladder cancer (BC) is the 10th most common neoplasia worldwide and holds expensive treatment costs due to its high recurrence rates, resistance to therapy and the need for lifelong surveillance. Thus, it is necessary to improve the current therapy options and identify more effective treatments for BC. Biological models capable of recapitulating the characteristics of human BC pathology are essential in evaluating the effectiveness of new therapies. Currently, the most commonly used BC models are experimentally induced murine models and spontaneous canine models, which are either insufficient due to their small size and inability to translate results to clinical basis (murine models) or rarely spontaneously observed BC (canine models). Pigs represent a potentially useful animal for the development of personalized tumors due to their size, anatomy, physiology, metabolism, immunity, and genetics similar to humans and the ability to experimentally induce tumors. Pigs have emerged as suitable biomedical models for several human diseases. In this sense, the present perspective focuses on the genetic basis for BC; presents current BC animal models available along with their limitations; and proposes the pig as an adequate animal to develop humanized large animal models of BC. Genetic alterations commonly found in human BC can be explored to create genetically defined porcine models, including the BC driver mutations observed in the FGFR3, PIK3CA, PTEN, RB1, HRAS, and TP53 genes. The development of such robust models for BC has great value in the study of pathology and the screening of new therapeutic and diagnostic approaches to the disease.

Transgenic Animal Models of Bladder Cancer

Traditional animal models for cancer research represent an excellent experimental tool in bridging the gap between pre-clinical and clinical studies. The advances in gene transfer technologies allow the generation of transgenic animal models through the integration of the gene of interest into the animal models through gene transfer methods. Overcoming the limitations of traditional animal models, transgenic animal models are beneficial for studying carcinogenesis with respect to the genes. Besides, the utilization of transgenic animal models is also necessary for the development of novel targeted therapy. Bladder cancer (BC) is the most common cancer type worldwide and effective therapies targeting BC are urgently needed. Thus, with the delineation of molecular signatures of BC pathogenesis, the research involving transgenic animal models of BC will facilitate the development of clinical medicine, thereby improving the clinical outcome of BC patients in the future.

Spontaneous and Chemically-induced Bladder Cancer Animal Model

Investigations using animal model systems have been enlightening us with the biology underpinning the development of bladder cancer besides strengthening the existing therapy to improve the clinical outcome in patients. To date, spontaneous and chemical inductions are the classical methods in the generation of animal models of bladder cancer. Attributed to many benefits such as simple protocols and lower maintenance cost, these animal models are widely applied in the investigations of bladder cancer pathogenesis and screening of therapeutic drug. In this review, we give an overview of spontaneous- and chemically-induced bladder cancer animal models accompanying by the pros and cons of these two types of models. Furthermore, various chemical carcinogens used in the induction are discussed with the potential benefits and pitfalls in the establishment of animal models. This review will provide insightful information about the selection of the correct method in establishing the animal models of bladder cancer which are instrumental for studying potential therapeutic agents that target bladder cancer.

Priming with percutaneous bacillus Calmette-Guerin (BCG) prior to intravesical BCG treatment safely improves BCG-specific response in patients with bladder cancer

Abstract Bacillus Calmette-Guérin (BCG) is the gold standard immunologic agent for patients with high-grade non-muscle invasive bladder cancer (NMIBC). Nevertheless, responses to BCG are heterogeneous and limited options exist when BCG therapy fails. Preclinical data in animal models of bladder cancer (BC) suggests that priming with percutaneous BCG vaccine prior to intravesical BCG instillation can enhance BCG-specific immunity and improve outcome. To study the safety, immunogenicity and preliminary efficacy of this approach, we administered percutaneous BCG 21 days prior to intravesical BCG instillation in “prime patients” with NMIBC (n=13) in a prospective single-arm clinical trial. Immune responses and clinical outcomes were monitored and compared to a contemporaneous cohort of “control patients” (n=9) receiving intravesical BCG without prior percutaneous BCG. Priming was well tolerated and no grade ≥3 adverse events were observed. Compared to control, prime patients had improvement in both local and systemic measures of BCG-specific immunity, scored by increased post-BCG urinary IL-8 and IL-17A and increased circulating CD4, CD8, and γδ T cell proliferation and effector function in response to BCG. Furthermore, ex vivo cytotoxicity of circulating NK and γδ T cells against RT4 BC was significantly increased in prime patient after BCG treatment and was mediated in part by NKG2D, suggesting an important role of innate effector immune mechanisms underlying BCG’s antitumor activity. Remarkably, no prime patients progressed whereas 3 out of 9 control patients progressed to muscle-invasive disease and underwent cystectomy. Thus, BCG priming safely enhances BCG-specific immunity and could improve outcome for patients with NMIBC.

Apple polyphenol decelerates bladder cancer growth involving apoptosis and cell cycle arrest in N-butyl-N-(4-hydroxybutyl) nitrosamine-induced experimental animal model

Apple polyphenol (AP) was found to possess the potential to prevent cancers. Previously, our study showed AP can trigger bladder transitional carcinoma cells to apoptosis and regulate its cell cycle. This study is aimed to evaluate the anticancer effect of AP in urinary bladder carcinoma in vivo. A rat model of bladder cancer was induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN). Tumours were analyzed with immunohistochemical analysis and immunoblot assay. The results showed urinary bladder cancer was established after the administration of OH-BBN. AP can decrease the tumour progression under the monitor of bladder sonography. Analysis of tumour specimens from AP-treated rats showed significant decrease in the expression of Bcl2, cyclin B1, and PCNA, and increase in the expression of p-Chk2 (Thr-68), Bax, and Cip1/p21. The experimental evidences revealed that AP can modulate apoptosis accompanying with cell cycle in animal model of bladder cancer as well as in in vitro system.

Insights from animal models of bladder cancer: recent advances, challenges, and opportunities.

Bladder cancer (urothelial cancer of the bladder) is the most common malignancy affecting the urinary system with increasing incidence and mortality. Treatment of bladder cancer has not advanced in the past 30 years. Therefore, there is a crucial unmet need for novel therapies, especially for high grade/stage disease that can only be achieved by preclinical model systems that faithfully recapitulate the human disease. Animal models are essential elements in bladder cancer research to comprehensively study the multistep cascades of carcinogenesis, progression and metastasis. They allow for the investigation of premalignant phases of the disease that are not clinically encountered. They can be useful for identification of diagnostic and prognostic biomarkers for disease progression and for preclinical identification and validation of therapeutic targets/candidates, advancing translation of basic research to clinic. This review summarizes the latest advances in the currently available bladder cancer animal models, their translational potential, merits and demerits, and the prevalent tumor evaluation modalities. Thereby, findings from these model systems would provide valuable information that can help researchers and clinicians utilize the model that best answers their research questions.

Effect of green tea polyphenol on changes in cancer-related factors in a mouse model of bladder cancer.

329 Background: Many studies have demonstrated the anti-cancer effects of green tea polyphenol (GTP) in a variety of malignancies including bladder cancer, and epidemiologic studies have shown that green tea consumption reduces cancer risk. New cancer treatment strategies in combination with GTP intake have been recommended for several types of cancer. Thus, GTP is thought to be useful not only for cancer prevention but also for treatment. However, the mechanistic basis of these effects is not well understood. Hence, The aims of this study is to clarify the molecular mechanisms of GTP-induced anti-cancer effects, we used a mouse model of chemically induced bladder cancer. Methods: C3H/He mice (8 weeks old; n = 46) were treated with 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) solution for 14–24 weeks. Mice in the BBN + GTP group (n = 47) were also treated with 0.5% GTP solution over the same period. Tumor cell proliferation, and microvessel density were evaluated along with immunohistochemical analysis of human antigen R (HuR), vascular endothelial growth factor (VEGF)-A, cyclooxygenase (COX)-2, and hemeoxygenase (HO)-1 expression. Results: Cytoplasmic HuR expression in cancer cells was higher at 14 and 24 weeks in the BBN than in the control group and was associated with increased invasion of tumor cells in muscle. However, these effects were not observed in the BBN + GTP group. A multivariate analysis of GTP intake and cytoplasmic HuR expression revealed that GTP was independently associated with COX-2 and HO-1 expression, while cytoplasmic HuR expression was associated with COX-2 and VEGF-A levels. Expression of COX-2 and HO-1 was associated with cell proliferation and that of VEGF-A and HO-1 was associated with angiogenesis. In regard to nuclear HuR, its expression was not associated with any parameters, such as carcinogenesis, muscle invasion, and GTP intake. Conclusions: Our results supported the opinion that GTP intake can suppress tumor progression and malignant behavior in animal model of bladder cancer. In addition, we speculate that GTP directly and indirectly suppresses tumor cell proliferation and angiogenesis via HuR-related pathways in bladder cancer tissue.

Green Tea Polyphenol Induces Changes in Cancer-Related Factors in an Animal Model of Bladder Cancer.

Green tea polyphenol (GTP) suppresses carcinogenesis and aggressiveness in many types of malignancies including bladder cancer. However, the mechanistic basis of these effects is not well understood. This was investigated in the present study using a mouse model of chemically induced bladder cancer. C3H/He mice (8 weeks old; n = 46) were treated with 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) solution for 14–24 weeks. Mice in the BBN + GTP group (n = 47) were also treated with 0.5% GTP solution over the same period. Tumor cell proliferation and microvessel density were evaluated along with immunohistochemical analysis of human antigen (Hu)R, vascular endothelial growth factor (VEGF)-A, cyclooxygenase (COX)-2, and hemeoxygenase (HO)-1 expression. Cytoplasmic HuR expression in cancer cells was higher at 14 and 24 weeks in the BBN than in the control group and was associated with increased invasion of tumor cells in muscle. However, these effects were not observed in the BBN + GTP group. A multivariate analysis of GTP intake and cytoplasmic HuR expression revealed that GTP was independently associated with COX-2 and HO-1 expression, while cytoplasmic HuR expression was associated with COX-2 and VEGF-A levels. Expression of COX-2 and HO-1 was associated with cell proliferation and that of VEGF-A and HO-1 was associated with angiogenesis. Nuclear HuR expression was not associated with any parameters such as carcinogenesis, muscle invasion, and GTP intake. These results indicate that GTP intake can suppress tumor progression and malignant behavior in an animal model of bladder cancer. We also speculate that GTP directly and indirectly suppresses tumor cell proliferation and angiogenesis via HuR-related pathways in bladder cancer.

Molecular targets in urothelial cancer: detection, treatment, and animal models of bladder cancer.

Bladder cancer remains one of the most expensive cancers to treat in the United States due to the length of required treatment and degree of recurrence. In order to treat bladder cancer more effectively, targeted therapies are being investigated. In order to use targeted therapy in a patient, it is important to provide a genetic background of the patient. Recent advances in genome sequencing, as well as transcriptome analysis, have identified major pathway components altered in bladder cancer. The purpose of this review is to provide a broad background on bladder cancer, including its causes, diagnosis, stages, treatments, animal models, as well as signaling pathways in bladder cancer. The major focus is given to the PI3K/AKT pathway, p53/pRb signaling pathways, and the histone modification machinery. Because several promising immunological therapies are also emerging in the treatment of bladder cancer, focus is also given on general activation of the immune system for the treatment of bladder cancer.

Nanotechnology and cancer: improving real-time monitoring and staging of bladder cancer with multimodal mesoporous silica nanoparticles.

BackgroundDespite being one of the most common cancers, bladder cancer is largely inefficiently and inaccurately staged and monitored. Current imaging methods detect cancer only when it has reached “visible” size and has significantly disrupted the structure of the organ. By that time, thousands of cells will have proliferated and perhaps metastasized. Repeated biopsies and scans are necessary to determine the effect of therapy on cancer growth. In this report, we describe a novel approach based on multimodal nanoparticle contrast agent technology and its application to a preclinical animal model of bladder cancer. The innovation relies on the engineering core of mesoporous silica with specific scanning contrast properties and surface modification that include fluorescence and magnetic resonance imaging (MRI) contrast. The overall dimensions of the nano-device are preset at 80–180 nm, depending on composition with a pore size of 2 nm. MethodsTo facilitate and expedite discoveries, we combined a well-known model of bladder cancer and our novel technology. We exposed nanoparticles to MB49 murine bladder cancer cells in vitro and found that 70 % of the cells were labeled by nanoparticles as measured by flow cytometry. The in vivo mouse model for bladder cancer is particularly well suited for T1- and T2-weighted MRI. ResultsUnder our experimental conditions, we demonstrate that the nanoparticles considerably improve tumor definition in terms of volumetric, intensity and structural characteristics. Important bladder tumor parameters can be ascertained, non-invasively, repetitively, and with great accuracy. Furthermore, since the particles are not biodegradable, repetitive injection is not required. This feature allows follow-up diagnostic evaluations during cancer treatment. Changes in MRI signals show that in situ uptake of free particles has predilection to tumor cells relative to normal bladder epithelium. The particle distribution within the tumors was corroborated by fluorescent microscopy of sections of excised bladders. In addition, MRI imaging revealed fibrous finger-like projections into the tumors where particles insinuated themselves deeply. This morphological characteristic was confirmed by fluorescence microscopy. ConclusionsThese findings may present new options for therapeutic intervention. Ultimately, the combination of real-time and repeated MRI evaluation of the tumors enhanced by nanoparticle contrast may have the potential for translation into human clinical studies for tumor staging, therapeutic monitoring, and drug delivery.

Targeted therapies in bladder cancer: an overview of in vivo research.

Survival of patients with muscle-invasive bladder cancer is poor and new therapies are needed. Currently, none of the targeted agents that are approved for cancer therapy have been approved for the treatment of bladder cancer and the few clinical trials that have been performed had limited success, often owing to a lack of efficacy and toxic effects. However, many other novel targeted agents have been investigated in animal models of bladder cancer. EGFR, FGFR-3, VEGF, mTOR, STAT3, the androgen receptor and CD24 are molecular targets that could be efficiently inhibited, resulting in reduced tumour growth, and that have been investigated in multiple independent studies. Several other targets, for example COX-2, IL-12, Bcl-xL, livin and choline kinase α, have also been observed to inhibit tumour growth, but these findings have not been replicated to date. Limitations of several studies include the use of cell lines with mutations downstream of the target, providing resistance to the tested therapy. Furthermore, certain technologies, such as interfering RNAs, although effective in vitro, are not yet ready for clinical applications. Further preclinical research is needed to discover and evaluate other possible targets, but several validated targets are now available to be studied in clinical trials.