Vitamin A Rich Diet Diminishes Early Urothelial Carcinogenesis by Altering Retinoic Acid Signaling

Therapeutic effect of targeted antioxidant natural products

The exploration of targeted therapy has proven to be a highly promising avenue in the realm of drug development research. The human body generates a substantial amount of free radicals during metabolic processes, and if not promptly eliminated, these free radicals can lead to oxidative stress, disrupting homeostasis and potentially contributing to chronic diseases and cancers. Before the development of contemporary medicine with synthetic pharmaceuticals and antioxidants, there was a long-standing practice of employing raw, natural ingredients to cure a variety of illnesses. This practice persisted even after the active antioxidant molecules were known. The ability of natural antioxidants to neutralise excess free radicals in the human body and so prevent and cure a wide range of illnesses. The term "natural antioxidant" refers to compounds derived from plants or other living organisms that have the ability to control the production of free radicals, scavenge them, stop free radical-mediated chain reactions, and prevent lipid peroxidation. These compounds have a strong potential to inhibit oxidative stress. Phytochemicals (antioxidants) derived from plants, such as polyphenols, carotenoids, vitamins, and others, are central to the discussion of natural antioxidants. Not only may these chemicals increase endogenous antioxidant defenses, affect communication cascades, and control gene expression, but they have also shown strong free radical scavenging properties. This study comprehensively summarizes the primary classes of natural antioxidants found in different plant and animal source that contribute to the prevention and treatment of diseases. Additionally, it outlines the research progress and outlines future development prospects. These discoveries not only establish a theoretical groundwork for pharmacological development but also present inventive ideas for addressing challenges in medical treatment.

Redox System and Oxidative Stress-Targeted Therapeutic Approaches in Bladder Cancer

Bladder cancer (BCa) is the most common genitourinary malignancy, with a high global incidence and recurrence rate that is paired with an increasing caregiver burden and higher financial cost, in addition to increasing morbidity and mortality worldwide. Histologically, BCa is categorized into non-muscle invasive, muscle invasive, and metastatic BCa, on the basis of which the therapeutic strategy is determined. Despite all innovations and recent advances in BCa research, conventional therapies such as chemotherapy, immunotherapy, radiotherapy, and surgery fall short in the complete management of this important malignancy. Besides this worrying trend, the molecular basis of BCa development also remains poorly understood. Burgeoning evidence from experimental and clinical studies suggests that oxidative stress resulting from an imbalance between reactive oxygen species (ROS) generation and the body's antioxidant production plays an integral role in BCa development and progression. Hence, ROS-induced oxidative stress-related pathways are currently under investigation as potential therapeutic targets of BCa. This review focuses on our current understanding regarding ROS-associated pathways in BCa pathogenesis and progression, as well as on antioxidants as potential adjuvants to conventional BCa therapy.

Urinary Bladder Cancer Induced by N-Butyl-N-(4-Hydroxybutyl)-Nitrosamine

Urinary bladder cancer is the tenth most common cancer worldwide with high morbidity and mortality. The majority of bladder cancers are urothelial carcinomas. More than half are papillomas or the papillary urothelial carcinomas (stages Ta and T1), which have a relatively good prognosis. Squamous cell carcinomas have a variable survival rate, while carcinomas in situ (Tis) can progress to muscle-invasive urothelial carcinomas (T2) with a poor prognosis. The most challenging feature of bladder cancer is its high recurrence rate, ranging from 50% to 90% of cases. The N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) model is an invaluable experimental tool for bladder cancer research, as BBN-induced bladder cancer in rodents resembles human bladder cancer in its morphological, biological, and molecular features. We present here a detailed protocol for the treatment of mice and the main expected results.

Study of the Anti-Inflammatory Mechanism of β-Carotene Based on Network Pharmacology

β-carotene is known to have pharmacological effects such as anti-inflammatory, antioxidant, and anti-tumor properties. However, its main mechanism and related signaling pathways in the treatment of inflammation are still unclear. In this study, component target prediction was performed by using literature retrieval and the SwissTargetPrediction database. Disease targets were collected from various databases, including DisGeNET, OMIM, Drug Bank, and GeneCards. A protein-protein interaction (PPI) network was constructed, and enrichment analysis of gene ontology and biological pathways was carried out for important targets. The analysis showed that there were 191 unique targets of β-carotene after removing repeat sites. A total of 2067 targets from the three databases were integrated, 58 duplicate targets were removed, and 2009 potential disease action targets were obtained. Biological function enrichment analysis revealed 284 biological process (BP) entries, 31 cellular component (CC) entries, 55 molecular function (MF) entries, and 84 cellular pathways. The biological processes were mostly associated with various pathways and their regulation, whereas the cell components were mainly membrane components. The main molecular functions included RNA polymerase II transcription factor activity, DNA binding specific to the ligand activation sequence, DNA binding, steroid binding sequence-specific DNA binding, enzyme binding, and steroid hormone receptors. The pathways involved in the process included the TNF signaling pathway, sphingomyelin signaling pathway, and some disease pathways. Lastly, the anti-inflammatory signaling pathway of β-carotene was systematically analyzed using network pharmacology, while the molecular mechanism of β-carotene was further explored by molecular docking. In this study, the anti-inflammatory mechanism of β-carotene was preliminarily explored and predicted by bioinformatics methods, and further experiments will be designed to verify and confirm the predicted results, in order to finally reveal the anti-inflammatory mechanism of β-carotene.

Selective targeting of lectins and their macropinocytosis in urothelial tumours: translation from in vitro to ex vivo

Urinary bladder cancer can be treated by intravesical application of therapeutic agents, but the specific targeting of cancer urothelial cells and the endocytotic pathways of the agents are not known. During carcinogenesis, the superficial urothelial cells exhibit changes in sugar residues on the apical plasma membranes. This can be exploited for selective targeting from the luminal side of the bladder. Here we show that the plant lectins Jacalin (from Artocarpus integrifolia), ACA (from Amaranthus caudatus) and DSA (from Datura stramonium) selectively bind to the apical plasma membrane of low- (RT4) and high-grade (T24) cancer urothelial cells in vitro and urothelial tumours ex vivo. The amount of lectin binding was significantly different between RT4 and T24 cells. Endocytosis of lectins was observed only in cancer urothelial cells and not in normal urothelial cells. Transmission electron microscopy analysis showed macropinosomes, endosome-like vesicles and multivesicular bodies filled with lectins in RT4 and T24 cells and also in cells of urothelial tumours ex vivo. Endocytosis of Jacalin and ACA in cancer cells was decreased in vitro after addition of inhibitor of macropinocytosis 5-(N-ethyl-N-isopropyl) amiloride (EIPA) and increased after stimulation of macropinocytosis with epidermal growth factor (EGF). Clathrin, caveolin and flotillin did not colocalise with lectins. These results confirm that the predominant mechanism of lectin endocytosis in cancer urothelial cells is macropinocytosis. Therefore, we propose that lectins in combination with conjugated therapeutic agents are promising tools for improved intravesical therapy by targeting cancer cells.

Insights into vitamin A in bladder cancer, lack of attention to gut microbiota?

Vitamin A has long been associated with bladder cancer, and many exogenous vitamin A supplements, vitamin A derivatives, and synthetic drugs have been investigated over the years. However, the effectiveness of these strategies in clinical practice has not met expectations, and they have not been widely adopted. Recent medical research on intestinal flora has revealed that bladder cancer patients exhibit reduced serum vitamin A levels and an imbalance of gut microbiota. In light of the close relationship between gut microbiota and vitamin A, one can speculate that a complex regulatory mechanism exists between the two in the development and occurrence of bladder cancer. As such, further exploration of their interaction in bladder cancer may help guide the use of vitamin A for preventive purposes. During the course of this review, attention is paid to the influence of intestinal microbiota on the vitamin A metabolism and the RA signaling pathway, as well as the mutual promotion relationships between them in the prevention of bladder cancer, In addition, it emphasizes the importance of intestinal microbiota for bladder cancer prevention and treatment.

Role of EZH2 in Uterine Gland Development

Enhancer of zeste homolog 2 (EZH2) is a core component of polycomb repressive complex 2 that plays a vital role in transcriptional repression of gene expression. Conditional ablation of EZH2 using progesterone receptor (Pgr)-Cre in the mouse uterus has uncovered its roles in regulating uterine epithelial cell growth and stratification, suppressing decidual myofibroblast activation, and maintaining normal female fertility. However, it is unclear whether EZH2 plays a role in the development of uterine glands, which are required for pregnancy success. Herein, we created mice with conditional deletion of Ezh2 using anti-Mullerian hormone receptor type 2 (Amhr2)-Cre recombinase that is expressed in mesenchyme-derived cells of the female reproductive tract. Strikingly, these mice showed marked defects in uterine adenogenesis. Unlike Ezh2 Pgr-Cre conditional knockout mice, deletion of Ezh2 using Amhr2-Cre did not lead to the differentiation of basal-like cells in the uterus. The deficient uterine adenogenesis was accompanied by impaired uterine function and pregnancy loss. Transcriptomic profiling using next generation sequencing revealed dysregulation of genes associated with signaling pathways that play fundamental roles in development and disease. In summary, this study has identified an unrecognized role of EZH2 in uterine gland development, a postnatal event critical for pregnancy success and female fertility.

Vitamin A and Retinoids in Bladder Cancer Chemoprevention and Treatment: A Narrative Review of Current Evidence, Challenges and Future Prospects

Bladder cancer (BC) is the tenth most common cancer worldwide with a high recurrence rate, morbidity and mortality. Therefore, chemoprevention and improved treatment of BC are of paramount importance. Epidemiological studies suggest that adequate vitamin A intake may be associated with reduced BC risk. In addition, retinoids, natural and synthetic derivatives of vitamin A, are intensively studied in cancer research due to their antioxidant properties and their ability to regulate cell growth, differentiation, and apoptosis. Findings from in vivo and in vitro models of BC show great potential for the use of retinoids in the chemoprevention and treatment of BC. However, translation to the clinical practice is limited. In this narrative review we discuss: (i) vitamin A and retinoid metabolism and retinoic acid signalling, (ii) the pathobiology of BC and the need for chemoprevention, (iii) the epidemiological evidence for the role of dietary vitamin A in BC, (iv) mechanistic insights obtained from in vivo and in vitro models, (v) clinical trials of retinoids and the limitations of retinoid use, (vi) novel systems of retinoid delivery, and (vii) components of retinoid signalling pathways as potential novel therapeutic targets.

Immunohistochemistry as a paramount tool in research of normal urothelium, bladder cancer and bladder pain syndrome

The urothelium, an epithelium of the urinary bladder, primarily functions as blood-urine permeability barrier. The urothelium has a very slow turnover under normal conditions but is capable of extremely fast response to injury. During regeneration urothelium either restores normal function or undergoes altered differentiation pathways, the latter being the cause of several bladder diseases. In this review, we describe the structure of the apical plasma membrane that enables barrier function, the role of urothelium specific proteins uroplakins and the machinery for polarized membrane transports in terminally differentiated superficial umbrella cells. We address key markers, such as keratins, cancer stem cell markers, retinoic acid signalling pathway proteins and transient receptor potential channels and purinergic receptors that drive normal and altered differentiation in bladder cancer and bladder pain syndrome. Finally, we discuss uncertainties regarding research, diagnosis and treatment of bladder pain syndrome. Throughout the review, we emphasise the contribution of immunohistochemistry in advancing our understanding of processes in normal and diseased bladder as well as the most promising possibilities for improved bladder cancer and bladder pain syndrome management.

BBN-driven urinary bladder cancer mouse model

Around 3% of new cancer diagnoses and 2% of all cancer deaths every year are caused by urinary bladder cancer (BC). This indicates a great need for intensive studying of BC by using different approaches including indispensable mice models. The most common preclinical mouse model of bladder carcinogenesis relies on the use of a nitrosamine compound, N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) which causes high-grade, invasive tumors in the urinary bladder. BBN-induced bladder cancer in mice recapitulates the histology and manifests genetic alterations similar to human muscle-invasive bladder cancer. Here we present a detailed protocol for the induction of BC in mice which is based on the administration of 0.05%-0.1% BBN in drinking water. Six-to-eight-week-old mice are treated orally with BBN for 12weeks and tumors are expected 8weeks after the termination of BBN regimen. Histopathologic examination of the lesions should be routinely assessed after hematoxylin and eosin staining by an experienced pathologist and it can vary from urothelial dysplasia to invasive bladder cancer with glandular and squamous divergent differentiation, the incidence of which might depend on the mouse strain, gender, BBN concentration and the timeline of the protocol. Utilizing half of the urinary bladder tissue for the isolation and analysis of RNA, DNA and proteins provides a comprehensive insight into the biology of BC and reduces the number of mice per study. Finally, the successful use of the BC model can facilitate fundamental biomedical discoveries leading to novel diagnostic and therapeutic approaches with clinical benefits.