Biological similarities between murine chemical-induced and natural human bladder carcinogenesis

Anticancer effect of salidroside reduces viability through autophagy/PI3K/Akt and MMP-9 signaling pathways in human bladder cancer cells

Salidroside has a wide range of pharmacological activities, including antitumor, anti-inflammatory, analgesic, antibacterial, antiviral and anti-fertility abilities. In the present study, the effects of salidroside on the viability and apoptosis of bladder cancer cells, and the potential underlying mechanisms, were examined. In the present study, treatment with salidroside reduced cell viability, and induced apoptosis and caspase-9/3 activation in the T24 human bladder carcinoma cell line. Salidroside induced autophagy, promoted the protein expression of nucleoporin p62 and the microtubule-associated proteins 1A/1B light chain 3B, suppressed phosphoinositide 3-kinase (PI3K) and phosphorylated protein kinase B (p-Akt) expression, inhibited matrix metalloproteinase-9 (MMP-9) expression and increased that of Bcl-2-associated X protein, which functions as an apoptosis regulator in T24 cells. In the present study, it was demonstrated that the effect of salidroside reduced the viability and induced the apoptosis of bladder cancer cells through the autophagy/PI3K/Akt and MMP-9 signaling pathways.

Modeling human bladder cancer

INTRODUCTION

Bladder cancer is a major public health concern and the treatment options available are unable to significantly prevent disease recurrence and progression. The need for experimental tumor models to efficiently reproduce the pathology of human cancers has prompted researchers to attempt various approaches.

METHODS

A PubMed search combining the MeSH bladder cancer and models was executed in March 2017.

RESULTS

We review the advantages and limitations of currently available in vitro 2D and 3D bladder cancer models as well as in vivo rodent models. To date, despite the description of a variety of animal models (including transplantable, carcinogen-induced and genetically engineered models), the establishment of reliable, simple, practicable and reproducible animal models remains an ongoing challenge. Recently, sophisticated 3D culture systems have been designed to better recapitulate the phenotypic and cellular heterogeneity as well as microenvironmental aspects of in vivo tumor growth, while being more flexible to conduct repeated experiments.

CONCLUSION

Selecting the most appropriate model for a specific application will maximize the conversion of potential therapies from the laboratory to clinical practice and requires an understanding of the various models available.

Implementation of Humane Endpoints in a Urinary Bladder Carcinogenesis Study in Rats

BACKGROUND/AIM

This study aimed to evaluate the utility of several biological parameters for the prediction of tumor development and animal welfare in a rat model of urinary bladder cancer.

MATERIALS AND METHODS

The control group (n=9) received tap water while the test group (n=12) received the carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in drinking water. A score sheet with biological variables was used to monitor animals' welfare. Body weight, food and drink consumption and rectal temperature were measured weekly. Blood and urine samples were collected.

RESULTS

Animals from the control group exhibited a slightly higher body weight and body weight gain. The final urine volume was higher in BBN group (p<0.05). All animals from the BBN group exhibited macroscopic hematuria at 35th week. Four animals were anemic in the last week of the experiment.

CONCLUSION

The routine control of hematuria was a useful non-invasive biomarker of disease progression that may be used as a potential earlier humane endpoint. Animals did not show clinical signs of suffering that justified their sacrifice before the end of the study.

Preventive effect of intravesical ozone supplementation on n-methyl-n-nitrosourea-induced non-muscle invasive bladder cancer in male rats

Although non-muscle invasive bladder cancer (NMIBC) is widely seen in men, most laboratory studies of new intravesical therapies to prevent NMIBC have been conducted on female animals. In addition, ozone (O₃) has been shown to be a beneficial agent as an intravesical application in the treatment of various disorders. In the current study, we evaluated the immunohistopathological and oxidative-antioxidative effects of intravesical O₃ treatment on n-methyl-n-nitrosourea (MNU)-induced NMIBC. Male Wistar-Albino rats (n=51) were divided into four groups: sham (n=6), O₃ only (n=15), MNU only (n=15), and MNU+O₃ (n=15). The MNU-only and MNU+O₃ groups received MNU, and the O₃-only group received saline every other week for 10 weeks. The MNU-only group received 1 ml saline in place of O₃ treatment, whereas the O₃-only and MNU+O₃ groups were treated with 1 ml 25 µg/ml O₃ between the 7th and 12th weeks. Rat bladders were collected in the 15th week for immunohistopathology and oxidant-antioxidant quantitation. Oxidant-antioxidant parameters were determined by ELISA. Although all surviving rats in the MNU-only group had preneoplastic (4/11, 36.4%) or neoplastic changes (7/11, 63.6%), a completely normal urothelium was observed in 2 rats (2/12, 16.7%) in the MNU+O₃-group (P=0.478). More high-grade lesions were observed in the MNU-only group (4/11, 36.4%) than in the MNU+O₃ group (1/12, 8.3%) (P=0.120). All oxidant-antioxidant parameters significantly increased (P<0.05) in the O₃-only group compared with the sham group. However, only antioxidant superoxide dismutase was remarkably higher (178.9%, P=0.060) in the MNU+O₃ group compared with the MNU-only group. This is the first methodologically and pathologically well-described male rat orthotopic bladder carcinogenesis model with intravesical MNU and administration of O₃ in NMIBC.

Abnormal Protein Glycosylation and Activated PI3K/Akt/mTOR Pathway: Role in Bladder Cancer Prognosis and Targeted Therapeutics

Muscle invasive bladder cancer (MIBC, stage ≥T2) is generally associated with poor prognosis, constituting the second most common cause of death among genitourinary tumours. Due to high molecular heterogeneity significant variations in the natural history and disease outcome have been observed. This has also delayed the introduction of personalized therapeutics, making advanced stage bladder cancer almost an orphan disease in terms of treatment. Altered protein glycosylation translated by the expression of the sialyl-Tn antigen (STn) and its precursor Tn as well as the activation of the PI3K/Akt/mTOR pathway are cancer-associated events that may hold potential for patient stratification and guided therapy. Therefore, a retrospective design, 96 bladder tumours of different stages (Ta, T1-T4) was screened for STn and phosphorylated forms of Akt (pAkt), mTOR (pmTOR), S6 (pS6) and PTEN, related with the activation of the PI3K/Akt/mTOR pathway. In our series the expression of Tn was residual and was not linked to stage or outcome, while STn was statically higher in MIBC when compared to non-muscle invasive tumours (p = 0.001) and associated decreased cancer-specific survival (log rank p = 0.024). Conversely, PI3K/Akt/mTOR pathway intermediates showed an equal distribution between non-muscle invasive bladder cancer (NMIBC) and MIBC and did not associate with cancer-specif survival (CSS) in any of these groups. However, the overexpression of pAKT, pmTOR and/or pS6 allowed discriminating STn-positive advanced stage bladder tumours facing worst CSS (p = 0.027). Furthermore, multivariate Cox regression analysis revealed that overexpression of PI3K/Akt/mTOR pathway proteins in STn+ MIBC was independently associated with approximately 6-fold risk of death by cancer (p = 0.039). Mice bearing advanced stage chemically-induced bladder tumours mimicking the histological and molecular nature of human tumours were then administrated with mTOR-pathway inhibitor sirolimus (rapamycin). This decreased the number of invasive lesions and, concomitantly, the expression of STn and also pS6, the downstream effector of the PI3K/Akt/mTOR pathway. In conclusion, STn was found to be marker of poor prognosis in bladder cancer and, in combination with PI3K/Akt/mTOR pathway evaluation, holds potential to improve the stratification of stage disease. Animal experiments suggest that mTOR pathway inhibition could be a potential therapeutic approach for this specific subtype of MIBC.

Comparative proteomic analyses of urine from rat urothelial carcinoma chemically induced by exposure to N-butyl-N-(4-hydroxybutyl)-nitrosamine

Bladder cancer is estimated to be the ninth most common malignancy with a high rate of recurrence and progression despite therapy, early diagnosis being crucial for timely intervention.

SLCO1B1, SLCO2B1, and SLCO1B3 polymorphisms and susceptibility to bladder cancer risk

A variety of carcinogens are excreted in urine and may be actively transported by organic anion-transporting polypeptides that encoded by SLCOs. In this study, we evaluated whether single nucleotide polymorphisms (SNPs) in SLCO1B1, SLCO2B1, and SLCO1B3 are associated with bladder cancer susceptibility. Our results, for the first time, indicated that polymorphisms of SLCO1B1 rs2306283 might be associated with bladder cancer risk. Therefore, SNPs in SLCO1B1 may be potential biomarkers for assessing the risk of bladder cancer.

Bladder cancer-induced skeletal muscle wasting: disclosing the role of mitochondria plasticity

Loss of skeletal muscle is a serious consequence of cancer as it leads to weakness and increased risk of death. To better understand the interplay between urothelial carcinoma and skeletal muscle wasting, cancer-induced catabolic profile and its relationship with muscle mitochondria dynamics were evaluated using a rat model of chemically induced urothelial carcinogenesis by the administration of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). The histologic signs of non-muscle-invasive bladder tumors observed in BBN animals were related to 17% loss of body weight and high serum levels of IL-1β, TNF-α, TWEAK, C-reactive protein, myostatin and lactate and high urinary MMPs activities, suggesting a catabolic phenotype underlying urothelial carcinoma. The 12% loss of gastrocnemius mass was related to mitochondrial dysfunction, manifested by decreased activity of respiratory chain complexes due to, at least partially, the impairment of protein quality control (PQC) systems involving the mitochondrial proteases paraplegin and Lon. This was paralleled by the accumulation of oxidatively modified mitochondrial proteins. In overall, our data emphasize the relevance of studying the regulation of PQC systems in cancer cachexia aiming to identify therapeutic targets to counteract muscle wasting.