Role of Sonic Hedgehog (Shh) Signaling in Bladder Cancer Stemness and Tumorigenesis

Bladder Cancer and the Urinary Microbiome-New Insights and Future Directions: A Review

The presence of a microbiome in the urinary system has been established through recent advancements in technology and investigation of microbial communities in the human body. The study of the taxonomic and genomic ecology of microbial communities has been greatly improved by the use of metagenomics. The research in this area has expanded our understanding of microbial ecosystems and shows that the urinary tract contains over 100 species from over 50 genera, with Lactobacillus, Gardnerella, and Streptococcus being the most common. Previous studies have suggested that the microbiota in the urinary tract may play a role in carcinogenesis by causing chronic inflammation and genotoxicity, but more research is needed to reach a definite conclusion. This is a narrative review. We conducted a search for relevant publications by using the databases Medline/PubMed and Google Scholar. The search was based on keywords such as "urinary microbiome," "bladder cancer," "carcinogenesis," "urothelial carcinoma," and "next-generation sequencing." The retrieved publications were then reviewed to study the contribution of the urinary microbiome in the development of bladder cancer. The results have been categorized into four sections to enhance understanding of the urinary microbiome and to highlight its role in the emergence of bladder cancer through alterations in the immune response that involve T-cells and antibodies. The immune system and microbiome play crucial roles in maintaining health and preventing disease. Manipulating the immune system is a key aspect of various cancer treatments, and certain gut bacteria have been linked to positive responses to immunotherapies. However, the impact of these treatments on the urinary microbiome, and how diet and lifestyle affect it, are not well understood. Research in this area could have significant implications for improving bladder cancer treatment and patient outcomes.

Targeted therapies in bladder cancer: signaling pathways, applications, and challenges

Bladder cancer (BC) is one of the most prevalent malignancies in men. Understanding molecular characteristics via studying signaling pathways has made tremendous breakthroughs in BC therapies. Thus, targeted therapies including immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and tyrosine kinase inhibitor (TKI) have markedly improved advanced BC outcomes over the last few years. However, the considerable patients still progress after a period of treatment with current therapeutic regimens. Therefore, it is crucial to guide future drug development to improve BC survival, based on the molecular characteristics of BC and clinical outcomes of existing drugs. In this perspective, we summarize the applications and benefits of these targeted drugs and highlight our understanding of mechanisms of low response rates and immune escape of ICIs, ADCs toxicity, and TKI resistance. We also discuss potential solutions to these problems. In addition, we underscore the future drug development of targeting metabolic reprogramming and cancer stem cells (CSCs) with a deep understanding of their signaling pathways features. We expect that finding biomarkers, developing novo drugs and designing clinical trials with precisely selected patients and rationalized drugs will dramatically improve the quality of life and survival of patients with advanced BC.

Construction and prognostic value of enhanced CT image omics model for noninvasive prediction of HRG in bladder cancer based on logistic regression and support vector machine algorithm

Background

Urothelial Carcinoma of the bladder (BLCA) is the most prevalent cancer of the urinary system. In cancer patients, HRG fusion is linked to a poor prognosis. The prediction of HRG expression by imaging omics in BLCA has not yet been fully investigated.

Methods

HRG expression in BLCA and healthy adjoining tissues was primarily identified utilizing data sourced from The Cancer Genome Atlas (TCGA). Using Kaplan-Meier survival curves and Landmark analysis, the relationship between HRG expression, clinicopathological parameters, and overall survival (OS) was investigated. Additionally, gene set variation analysis (GSVA) was conducted and CIBERSORTx was used to investigate the relationship between HRG expression and immune cell infiltration. The Cancer Imaging Archive (TCIA) provided CT images that were used for prognostic analysis, radiomic feature extraction, and construction of the model, respectively. The HRG expression levels were predicted using the constructed and evaluated LR and SMV models.

Results

HRG expression was shown to be substantially lower in BLCA tumors as opposed to that observed in normal tissues (p < 0.05). HRG expression had a close positive relationship with Eosinophils and a close negative relationship with B cells naive. The findings of the Landmark analysis illustrated that higher HRG was associated with improved patient survival at an early stage (P=0.048). The predictive performance of the two models, based on logistic regression analysis and support vector machine, was outstanding in the training and validation sets, yielding AUCs of 0.722 and 0.708, respectively, in the SVM model, and 0.727 and 0.662, respectively, in the LR.The models have good predictive efficiency.

Conclusion

HRG expression levels can have a significant impact on BLCA patients' prognoses. The radiomic characteristics can successfully predict the pre-surgical HRG expression levels, based on CT- Image omics.

A tumor microenvironment preoperative nomogram for prediction of lymph node metastasis in bladder cancer

Background

Growing evidence suggests that tumor metastasis necessitates multi-step microenvironmental regulation. Lymph node metastasis (LNM) influences both pre- and post-operative bladder cancer (BLCA) treatment strategies. Given that current LNM diagnosis methods are still insufficient, we intend to investigate the microenvironmental changes in BLCA with and without LNM and develop a prediction model to confirm LNM status.

Method

"Estimation of Stromal and Immune cells in Malignant Tumors using Expression data" (ESTIMATE) algorithm was used to characterize the tumor microenvironment pattern of TCGA-BLCA cohort, and dimension reduction, feature selection, and StrLNM signature construction were accomplished using least absolute shrinkage and selection operator (LASSO) regression. StrLNM signature was combined with the genomic mutation to establish an LNM nomogram by using multivariable logistic regression. The performance of the nomogram was evaluated in terms of calibration, discrimination, and clinical utility. The testing set from the TCGA-BLCA cohort was used for internal validation. Moreover, three independent cohorts were used for external validation, and BLCA patients from our cohort were also used for further validation.

Results

The StrLNM signature, consisting of 22 selected features, could accurately predict LNM status in the TCGA-BLCA cohort and several independent cohorts. The nomogram performed well in discriminating LNM status, with the area under curve (AUC) of 75.1% and 65.4% in training and testing datasets from the TCGA-BLCA cohort. Furthermore, the StrLNM nomogram demonstrated good calibration with p >0.05 in the Hosmer-Lemeshow goodness of fit test. Decision curve analysis (DCA) revealed that the StrLNM nomogram had a high potential for clinical utility. Additionally, 14 of 22 stably expressed genes were identified by survival analysis and confirmed by qPCR in BLCA patient samples in our cohort.

Conclusion

In summary, we developed a nomogram that included an StrLNM signature and facilitated the preoperative prediction of LNM status in BLCA patients.

Impact of SOX2 function and regulation on therapy resistance in bladder cancer

Bladder cancer (BC) is a malignant disease with high rates of recurrence and mortality. It is mainly classified as non-muscle-invasive BC and muscle-invasive BC (MIBC). Often, MIBC is chemoresistant, which, according to cancer stem cells (CSCs) theory, is linked to the presence of bladder cancer stem cells (BCSCs). Sex-determining region Y- (SRY) Box transcription factor 2 (SOX2), which is a molecular marker of BCSCs, is aberrantly over-expressed in chemoresistant BC cell lines. It is one of the standalone prognostic factors for BC, and it has an inherently significant function in the emergence and progression of the disease. This review first summarizes the role of SRY-related high-mobility group protein Box (SOX) family genes in BC, focusing on the SOX2 and its significance in BC. Second, it discusses the mechanisms relevant to the regulation of SOX2. Finally, it summarizes the signaling pathways related to SOX2 in BC, suggests current issues to be addressed, and proposes potential directions for future research to provide new insights for the treatment of BC.

Curcuminoids as Modulators of EMT in Invasive Cancers: A Review of Molecular Targets With the Contribution of Malignant Mesothelioma Studies

Curcuminoids, which include natural acyclic diarylheptanoids and the synthetic analogs of curcumin, have considerable potential for fighting against all the characteristics of invasive cancers. The epithelial-to-mesenchymal transition (EMT) is a fundamental process for embryonic morphogenesis, however, the last decade has confirmed it orchestrates many features of cancer invasiveness, such as tumor cell stemness, metabolic rewiring, and drug resistance. A wealth of studies has revealed EMT in cancer is in fact driven by an increasing number of parameters, and thus understanding its complexity has now become a cornerstone for defining future therapeutic strategies dealing with cancer progression and metastasis. A specificity of curcuminoids is their ability to target multiple molecular targets, modulate several signaling pathways, modify tumor microenvironments and enhance the host’s immune response. Although the effects of curcumin on these various parameters have been the subject of many reviews, the role of curcuminoids against EMT in the context of cancer have never been reviewed so far. This review first provides an updated overview of all EMT drivers, including signaling pathways, transcription factors, non-coding RNAs (ncRNAs) and tumor microenvironment components, with a special focus on the most recent findings. Secondly, for each of these drivers the effects of curcumin/curcuminoids on specific molecular targets are analyzed. Finally, we address some common findings observed between data reported in the literature and the results of investigations we conducted on experimental malignant mesothelioma, a model of invasive cancer representing a useful tool for studies on EMT and cancer.

Nanaomycin K inhibited epithelial mesenchymal transition and tumor growth in bladder cancer cells in vitro and in vivo

Nanaomycin K, derived from Streptomyces rosa subsp. notoensis OS-3966^T, has been discovered to have inhibitory bioactivity on epithelial-mesenchymal transition (EMT), an important mechanism of cancer cell invasion and migration. In this study, we examined the anti-EMT and anti-tumor effect of nanaomycin K in bladder cancer, where EMT has important roles in progression. We treated two bladder cancer lines, non-muscle-invasive KK47 and muscle-invasive T24, with nanaomycin K to determine the effects on cell proliferation, apoptosis and expression of EMT markers in vitro. Wound-healing assays were performed to assess cell invasion and migration. We conducted an in vivo xenograft study in which mice were inoculated with bladder cancer cells and treated with intratumoral administration of nanaomycin K to investigate its anti-tumor and EMT inhibition effects. As the results, nanaomycin K (50 µg/mL) significantly inhibited cell proliferation in KK47 (p < 0.01) and T24 (p < 0.01) in the presence of TGF-β, which is an EMT-inducer. Nanaomycin K (50 µg/mL) also significantly inhibited cell migration in KK47 (p < 0.01) and T24 (p < 0.01), and induced apoptosis in both cell lines in the presence of TGF-β (p < 0.01). Nanaomycin K increased the expression of E-cadherin and inhibited the expression of N-cadherin and vimentin in both cell lines. Nanaomycin K also decreased expression of Snail, Slug, phospho-p38 and phospho-SAPK/JNK especially in T24. Intratumoral administration of nanaomycin K significantly inhibited tumor growth in both KK47 and T24 cells at high dose (1.0 mg/body) (p = 0.009 and p = 0.003, respectively) with no obvious adverse events. In addition, nanaomycin K reversed EMT and significantly inhibited the expression of Ki-67 especially in T24. In conclusion, we demonstrated that nanaomycin K had significant anti-EMT and anti-tumor effects in bladder cancer cells, suggesting that nanaomycin K may be a therapeutic candidate for bladder cancer treatment.

Emerging Biomarkers for Predicting Bladder Cancer Lymph Node Metastasis

Bladder cancer is one of the leading causes of cancer deaths worldwide. Early detection of lymph node metastasis of bladder cancer is essential to improve patients' prognosis and overall survival. Current diagnostic methods are limited, so there is an urgent need for new specific biomarkers. Non-coding RNA and m6A have recently been reported to be abnormally expressed in bladder cancer related to lymph node metastasis. In this review, we tried to summarize the latest knowledge about biomarkers, which predict lymph node metastasis in bladder cancer and their mechanisms. In particular, we paid attention to the impact of non-coding RNA on lymphatic metastasis of bladder cancer and its specific molecular mechanisms, as well as some prediction models based on imaging, pathology, and biomolecules, in an effort to find more accurate diagnostic methods for future clinical application.

Propofol Inhibits the Proliferation, Migration, and Stem-like Properties of Bladder Cancer Mainly by Suppressing the Hedgehog Pathway

Bladder cancer is one of the most common malignancies. The existence of bladder cancer stem cells (BCSCs) has been suggested to underlie bladder tumor initiation and recurrence. Propofol is a commonly used intravenous anesthetic. Here, we find that propofol can dramatically block the activation of Hedgehog pathway in BCSCs. The propofol strongly repressed the growth of cancer cells. Attenuated proliferation and enhanced apoptosis of tumor cells were observed upon propofol stimulation. Furthermore, propofol reduced the self-renewal ability of BCSCs as well as the tumor formation. In conclusion, propofol is potentially used as a novel therapeutic agent for bladder cancer by targeting self-renewal through inhibiting Hedgehog pathway.

Cell-Intrinsic Tumorigenic Functions of PPARγ in Bladder Urothelial Carcinoma

The role of PPAR gamma (PPARγ) has been well characterized in the developmental process of adipogenesis, yet its aberrant expression patterns and functions in cancer subtypes are less understood. Although PPARγ has been recently demonstrated to play non-cell-autonomous roles in promoting bladder urothelial carcinoma (UC) progression, underlying mechanisms of the cell-intrinsic oncogenic activity remain unknown. Here, we report robust expression and nuclear accumulation of PPARγ in 47% of samples of patients with UC, exceeding mRNA expression patterns published by The Cancer Genome Atlas. In vitro assays revealed for the first time that treatment of UC cells with PPARγ inverse agonist or PPARG knockout by CRISPR-Cas9 reduces proliferation, migration, and invasion of multiple established UC cell lines, most strongly in those characterized by PPARG genomic amplification or activating mutations of RXRA, the obligate heterodimer of PPARγ. Through genome-wide approaches including chromatin immunoprecipitation sequencing and RNA sequencing, we define a novel set of PPARγ-regulated genes in UC, including Sonic Hedgehog (SHH). Similar to PPARγ, genetic inhibition of SHH reduces proliferation and motility. Finally, we demonstrate the PPARγ dependency of UC tumors in vivo by genetic and pharmacologic PPARγ inhibition in subcutaneous xenografts. Collectively, our data indicate that PPARγ promotes UC progression in a subset of patients, at least in part, through cell-autonomous mechanisms linked to SHH signaling. IMPLICATIONS: Genome-wide analysis of DNA-binding sites for oncogenic factor PPARγ revealed SHH as a novel downstream target involved in UC progression, providing important insight into the tumorigenic nature and molecular mechanism of PPARγ signaling in UC.

Spatiotemporal Expression of SHH/GLI Signaling in Human Fetal Bladder Development

Objectives: Sonic hedgehog (SHH) signaling is important in bladder development. Mice with defective hedgehog signaling develop bladder anomalies. Clinically, urinary tract malformations are reported in human fetuses and infants with mutations of SHH and related signaling pathway genes. Information on the expression of SHH and associated signaling genes in normal human bladder development is fragmentary. This study determined the temporal and spatial expression patterns of SHH signaling pathway components in human fetal bladders by immunohistochemistry (IHC). Material and Methods: Twenty-four bladder specimens from 16 male and 8 female human fetuses aged 12- to 36-week (wk) were obtained from the First Affiliated Hospital of Xi'an Jiaotong University. The tissue slides were processed for IHC staining with SHH, Patched1 (PTC-1), Patched2 (PTC-2), Smoothened (SMO), GLI1 and proliferating cell nuclear antigen (PCNA). The expression levels of each gene were analyzed by semi-quantitative histological scoring system. Results: High intensity of SHH and SMO expression was detected in developing bladder urothelial cells, with no staining in lamina propria (LP), but with minimal expression of SMO in differentiating smooth muscle (SM) layers. The spatial distribution pattern of PTC1 and GLI1 was more complex with minimal expression in the LP layer, moderate expression in the SM layer, and high expression in the urothelium. PTC2 expression was mainly localized in the urothelium and LP, but no expression in the SM layer. All of the SHH signaling components were detected in fetal bladder tissues throughout the development, with expression peaks at 12- and 23-wk, coinciding with high cell proliferation as indicated by PCNA staining in the cell nuclei of urothelium and SM. Conclusions: The autocrine SHH signaling in the developing urothelium, and paracrine SHH signaling in the developing smooth muscle layer, mediated by SMO, PTC-1 and GLI1 were demonstrated during human bladder development. Expression of SHH signaling components peaked at 12-and 23-wk. The first expression peak at 12-wk may relate to urothelium growth, SM induction, and dilation of the bladder cavity. The second expression peaked at 23-wk may relate to urothelium and SM layer differentiation.

Benzidine promotes the stemness of bladder cancer stem cells via activation of the Sonic hedgehog pathway

Substantial evidence suggests that cancer stem cells (CSCs) are the main cause of the initiation, progression and recurrence of tumors. Benzidine has been identified as a risk factor for bladder cancer. The aim of the present study was to investigate the effects of benzidine on bladder CSCs (BCSCs) and the possible mechanism underlying its action. The bladder cancer cell lines UM-UC-3 and EJ were maintained in serum-free medium and cells forming three-dimensional spheres were characterized as BCSCs. The sphere-forming cells were exposed to different concentrations of benzidine and vismodegib, and western blotting was performed to evaluate the expression of markers associated with CSCs and the Sonic hedgehog (SHH) signaling pathway. Flow cytometry was used to detect the distribution of cells in different phases of the cell cycle, and immunofluorescence staining was used to detect the protein expression of CD44. The results revealed that the levels of BCSC markers, namely CD133, CD44, aldehyde dehydrogenase 1-A1, Nanog and octamer-binding transcription factor-4, in the cell spheres were markedly elevated compared with those in cells cultured in serum-supplemented medium. Furthermore, benzidine increased the expression of BCSC markers and promoted the sphere-forming ability of the cells. In addition, it was observed that benzidine activated the SHH pathway, while inhibition of the Shh pathway using vismodegib diminished the promoting effects of benzidine on BCSCs. The findings of the present study indicate that benzidine promoted the stemness of BCSCs via activation of the SHH pathway, which may support further exploration of the molecular basis of the association between benzidine exposure and bladder oncogenesis.

Pathophysiological relationship between hypoxia associated oxidative stress, Epithelial-mesenchymal transition, stemness acquisition and alteration of Shh/ Gli-1 axis during oral sub-mucous fibrosis and oral squamous cell carcinoma

Oral sub-mucous fibrosis (OSF) is a pathophysiological state of oral cavity or oropharynx having a high chance of conversion to oral squamous cell carcinoma (OSCC). It involves fibrotic transformation of sub-epithelial matrix along with epithelial abnormalities. The present work aims to unveil the mechanistic domain regarding OSF to OSCC conversion exploring the scenario of hypoxia associated oxidative stress, epithelial-mesenchymal transition (EMT), metastasis and stemness acquisition. The study involves histopathological analysis of the diseased condition along with the exploration of oxidative stress status, assessment of mitochondrial condition, immunohistochemical analysis of HIF-1α, E-cadherin, vimentin, ERK, ALDH-1, CD133, Shh, Gli-1 and survivin expressions in the oral epithelial region together with the quantitative approach towards collagen deposition in the sub-epithelial matrix. Oxidative stress was found to be associated with type-II EMT in case of OSF attributing the development of sub-epithelial fibrosis and type-III EMT in case of OSCC favoring malignancy associated metastasis. Moreover, the acquisition of stemness during OSCC can also be correlated with EMT. Alteration of Shh and Gli-1 expression pattern revealed the mechanistic association of hypoxia with the phenotypic plasticity and disease manifestation in case of OSF as well as OSCC. Shh/ Gli-1 signaling can also be correlated with survivin mediated cytoprotective phenomenon under oxidative stress. Overall, the study established the correlative network of hypoxia associated oxidative stress, EMT and manifestation of oral pre-cancerous and cancerous condition in a holistic approach that may throw rays of hope in the therapeutic domain of the concerned diseases.

Astrocytic Sonic Hedgehog Alleviates Intracerebral Hemorrhagic Brain Injury via Modulation of Blood-Brain Barrier Integrity

Background: Intracerebral hemorrhage (ICH) is a fatal subtype of stroke that lacks effective therapy. Blood-brain barrier (BBB) damage is a hallmark of ICH-induced brain injury that leads to edema formation, leukocytes infiltration, influx of blood components into the perihematomal (PHE) region, and eventually brain injury. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted molecules that contribute to the association between these cells. Sonic hedgehog (SHH) derived from astrocytes promotes the maturity and integrity of the BBB by upregulating tight junctions (TJs) in brain capillary endothelial cells (ECs). However, the effect of SHH on BBB in ICH has not been investigated.

Methods: Cyclopamine (CYC) is a potent, selective inhibitor that specifically blocks the SHH signaling pathway. Here, we used pharmacological inhibitions (CYC and its derivatives) to determine a critical role of the SHH signaling pathway in promoting BBB integrity after ICH by mechanisms of regulating the TJ proteins in vivo and in vitro.

Results: The expression of astrocytic SHH was upregulated in mouse brains after ICH. Compared with the vehicle-treated group, inhibition of the SHH signaling pathway with CYC and its derivatives treatments aggravated neurological function deficits, brain edema, hematoma volume, and BBB impairment by downregulating TJs in ECs through the SHH-Gli-1 axis in vivo and in vitro.

Conclusions: SHH signaling pathway at the level of the BBB provides a barrier-promoting effect, suggesting that the SHH signaling pathway may function as a potential therapeutic target for restoring BBB function in ICH.

Targeting cancer stem cells in cholangiocarcinoma (Review)

The incidence of cholangiocarcinoma has been increasing steadily over the past 50 years, but the survival rates remained low due to the disease being highly resistant to non-surgical treatment interventions. Cancer stem cell markers are expressed in cholangiocarcinoma, suggesting that they serve a significant role in the physiology of the disease. Cancer stem cells are frequently implicated in tumor relapse and acquired resistance to a number of therapeutic strategies, including chemotherapy, radiation and immune checkpoint inhibitors. Novel targeted therapies to eradicate cancer stem cells may assist in overcoming treatment resistance in cholangiocarcinoma and reduce the rates of relapse and recurrence. Several signaling pathways have been previously documented to regulate the development and survival of cancer stem cells, including Notch, janus kinase/STAT, Hippo/yes-associated protein 1 (YAP1), Wnt and Hedgehog signaling. Although pharmacological agents have been developed to target these pathways, only modest effects were reported in clinical trials. The Hippo/YAP1 signaling pathway has come to the forefront in the field of cancer stem cell research due to its reported involvement in epithelium-mesenchymal transition, cell adhesion, organogenesis and tumorigenesis. In the present article, recent findings in terms of cancer stem cell research in cholangiocarcinoma were reviewed, where the potential therapeutic targeting of cancer stem cells in this disease was discussed.

Emerging Roles of Cancer Stem Cells in Bladder Cancer Progression, Tumorigenesis, and Resistance to Chemotherapy: A Potential Therapeutic Target for Bladder Cancer

Bladder cancer (BC) is a complex and highly heterogeneous stem cell disease associated with high morbidity and mortality rates if it is not treated properly. Early diagnosis with personalized therapy and regular follow-up are the keys to a successful outcome. Cancer stem cells (CSCs) are the leading power behind tumor growth, with the ability of self-renewal, metastasis, and resistance to conventional chemotherapy. The fast-developing CSC field with robust genome-wide screening methods has found a platform for establishing more reliable therapies to target tumor-initiating cell populations. However, the high heterogeneity of the CSCs in BC disease remains a large issue. Therefore, in the present review, we discuss the various types of bladder CSC heterogeneity, important regulatory pathways, roles in tumor progression and tumorigenesis, and the experimental culture models. Finally, we describe the current stem cell-based therapies for BC disease.

Monocarboxylate Transporter 1 in Brain Diseases and Cancers

Background:

Monocarboxylate Transporter 1 (MCT1), an important membrane transport protein, mediates the translocation of monocarboxylates together with protons across biological membranes. Due to its pathological significance, MCT1 plays an important role in the progression of some diseases, such as brain diseases and cancers.

Methods:

We summarize the general description of MCT1 and provide a comprehensive understanding of the role of MCT1 in brain diseases and cancers. Furthermore, this review discusses the opportunities and challenges of MCT1- targeting drug-delivery systems in the treatment of brain diseases and cancers.

Results:

In the brain, loss of MCT1 function is associated with pathologies of degeneration and injury of the nervous system. In tumors, MCT1 regulates the activity of signaling pathways and controls the exchange of monocarboxylates in aerobic glycolysis to affect tumor metabolism, proliferation and invasion. Meanwhile, MCT1 also acts as a good biomarker for the prediction and diagnosis of cancer progressions.

Conclusion:

MCT1 is an attractive transporter in brain diseases and cancers. Moreover, the development of MCT1- based small molecule drugs and MCT1 inhibitors in the clinic is promising. This review systematically summarizes the basic characteristics of MCT1 and its role in brain diseases and cancers, laying the foundation for further research on MCT1.

Communication Of Cancer Cells And Lymphatic Vessels In Cancer: Focus On Bladder Cancer

Bladder cancer is one of the most commonly diagnosed cancers worldwide and causes the highest lifetime treatment costs per patient. Bladder cancer is most likely to metastasize through lymphatic ducts, and once the lymph nodes are involved, the prognosis is poorly and finitely improved by current modalities. The underlying metastatic mechanism for bladder cancer is thus becoming a research focus to date. To identify relevant published data, an online search of the PubMed/Medline archives was performed to locate original articles and review articles regarding lymphangiogenesis and lymphatic metastasis in urinary bladder cancer (UBC), and was limited to articles in English published between 1998 and 2018. A further search of the clinical trials.gov search engine was conducted to identify both trials with results available and those with results not yet available. Herein, we summarized the unique mechanisms and biomarkers involved in the malignant progression of bladder cancer as well as their emerging roles in therapeutics, and that current data suggests that lymphangiogenesis and lymph node invasion are important prognostic factors for UBC. The growing knowledge about their roles in bladder cancers provides the basis for novel therapeutic strategies. In addition, more basic and clinical research needs to be conducted in order to identify further accurate predictive molecules and relevant mechanisms.

Possible correlation of sonic hedgehog signaling with epithelial-mesenchymal transition in muscle-invasive bladder cancer progression

PURPOSE

To investigate the role of sonic hedgehog (Shh) signaling and epithelial-mesenchymal transition (EMT) in bladder cancer progression and invasion.

METHODS

We cultured three bladder cancer cell lines, muscle-invasive T24 and 5637, and non-muscle-invasive KK47, in the presence of a recombinant-Shh (r-Shh) protein or cyclopamine, a Shh signaling inhibitor, to investigate proliferation and expression of EMT markers. Wound-healing assays and transwell assay were performed to evaluate cell invasion and migration. Mice were then inoculated with bladder cancer cells and treated with cyclopamine. Mouse tumor samples were stained for Shh signaling and EMT markers.

RESULTS

R-Shh protein enhanced cell proliferation, whereas cyclopamine significantly suppressed cell proliferation, especially in invasive cancer (5637 and T24) (p < 0.05). R-Shh protein promoted EMT, suppressed E-cadherin and enhanced N-cadherin and vimentin and Gli1, an Shh downstream molecule, while cyclopamine blocked EMT, especially in 5637 and T24. Cyclopamine also inhibited cell invasion and migration in vitro. In the animal study, intraperitoneal injection of cyclopamine significantly suppressed tumor growth in 5637 and T24 in mice (p = 0.01 and p = 0.004, respectively) and slightly suppressing KK47 tumor growth (p = 0.298). Significant cyclopamine-induced suppression of Gli1 in 5637 and T24 mouse tumors (both p = 0.03) was seen, suggesting that muscle-invasive bladder cancer may be more dependent on Shh signaling than non-muscle-invasive bladder cancer.

CONCLUSIONS

Shh signaling and EMT were especially enhanced in muscle-invasive bladder cancer progression and invasion, and suppressed by the inhibition of Shh signaling.

Inhibition of GLI2 with antisense-oligonucleotides: A potential therapy for the treatment of bladder cancer

The sonic hedgehog (SHH) signaling pathway plays an integral role in the maintenance and progression of bladder cancer (BCa) and SHH inhibition may be an efficacious strategy for BCa treatment. We assessed an in-house human BCa tissue microarray and found that the SHH transcription factors, GLI1 and GLI2, were increased in disease progression. A panel of BCa cell lines show that two invasive lines, UM-UC-3 and 253J-BV, both express these transcription factors but UM-UC-3 produces more SHH ligand and is less responsive in viability to pathway stimulation by recombinant human SHH or smoothened agonist, and less responsive to inhibitors including the smoothened inhibitors cyclopamine and SANT-1. In contrast, 253J-BV was highly responsive to these manipulations. We utilized a GLI1 and GLI2 antisense oligonucleotide (ASO) to bypass pathway mechanics and target the transcription factors directly. UM-UC-3 decreased in viability due to both ASOs but 253J-BV was only affected by GLI2 ASO. We utilized the murine intravesical orthotopic human BCa (mio-hBC) model for the establishment of noninvasive BCa and treated tumors with GLI2 ASO. Tumor size, growth rate, and GLI2 messenger RNA and protein expression were decreased. These results suggest that GLI2 ASO may be a promising new targeted therapy for BCa.

Sonic Hedgehog Expression is Associated with Lymph Node Invasion in Urothelial Bladder Cancer

Bladder cancer (BC) is a deadly disease characterized by high recurrence rates and frequent progression to an aggressive phenotype. Dysregulation of various signaling pathways have been implicated in BC tumorigenesis, however, the clinical relevance of sonic hedgehog pathway (Shh) remains under investigated. The aim of the current study was to analyze the prognostic value of Shh expression in patients with bladder carcinoma. Immunohistochemical expression of Shh was performed using tissue microarray with 128 specimens from bladder cancer patients. Kaplan-meier survival was analysed and correlation between Shh protein expression and patients' clinicopathological parameters wasexamined using Fisher's exact test. The immuno-staining results revealed that Shh protein exhibits cytoplasmic localization and is expressed in 49% of the analyzed bladder cancer cohort. Our data indicated that high Shh expression significantly correlated with increased lymph node metastasis (p = 0.02), however no association was reported between Shh expression and other clinicopatholigical parameters. High expression of sonic hedgehog was associated with lymph node invasion which may indicate that Shh might play an important role in progression and metastasis of bladder cancer.

MCT1 regulates aggressive and metabolic phenotypes in bladder cancer

Background: Monocarboxylate transporter isoform 1 (MCT1) is an important molecule in mediating lactate transportation. Recent studies have shown an oncogenic role of MCT1 in cancer development.

Methods: In this study, we aimed to investigate the expression and role of MCT1 in bladder cancer (BCa). MCT1 expression was detected in 124 BCa tissues and their clinicopathological significance was analyzed. We also used The Cancer Genome Atlas database to explore the prognostic association of MCT1 with BCa. Cell proliferation, migration and invasion assays were performed on BCa cells in which MCT1 was downregulated. The effect of MCT1 on BCa cell aerobic glycolysis, as well as its association with HIF-1α, was tested.

Results: We found that high MCT1 expression correlated with lymph node and distant metastasis. Patients with high-MCT1 expression showed shorter overall survival than those with low-MCT1 expression. Knockdown of MCT1 inhibited BCa cell proliferation, migration and invasion, and affected expression of epithelial-mesenchymal transition related proteins. Downregulation of MCT1 decreased lactate levels in cell medium, as well as HK2, GLUT1 and LDHB expression. In addition, MCT1 expression was partly dependent on HIF-1α.

Conclusions: Taken together, our study has shown a prognostic role of MCT1 in BCa, and provided potential diagnostic and therapeutic options for BCa patients.

Curcumin inhibits bladder cancer stem cells by suppressing Sonic Hedgehog pathway

Cancer stem cells (CSCs) is responsible for the recurrence of human cancers. Thus, targeting CSCs is considered to be a valid way for human cancer treatment. Curcumin is a major component of phytochemicals that exerts potent anticancer activities. However, the effect of curcumin on bladder cancer stem cells (BCSCs) remains to be elucidated. In this study, we investigated the mechanism of curcumin suppressing bladder cancer stem cells. In this study, UM-UC-3 and EJ cells were cultured in serum-free medium (SFM) to form cell spheres that was characterized as BCSCs. Then cell spheres were separately treated with different concentrations of curcumin and purmorphamine. Cell cycle analysis were used to determine the percentage of cells in different phases. Western blot and quantitative real-time PCR analysis were used to detect the expression of relative molecules. Immunofluorescence staining analysis were also utilized to measure the protein level of CD44. We found that CSC markers, including CD44, CD133, ALDH1-A1, OCT-4 and Nanog, were obviously highly expressed in cell spheres. Moreover, we observed that curcumin reduced the cell spheres formation, decreased the expression of CSC markers, suppressed cell proliferation and induced cell apoptosis. We also found that curcumin inhibited the activation of Shh pathway, while the inhibitory effects of curcumin on BCSCs could be weakened by upregulation of Sonic Hedgehog (Shh) pathway. Altogether, these data suggested that curcumin inhibited the activities of BCSCs through suppressing Shh pathway, which might be an effective chemopreventive agent for bladder cancer intervention.

Pituitary stem cell regulation: who is pulling the strings?

The pituitary gland plays a pivotal role in the endocrine system, steering fundamental processes of growth, metabolism, reproduction and coping with stress. The adult pituitary contains resident stem cells, which are highly quiescent in homeostatic conditions. However, the cells show marked signs of activation during processes of increased cell remodeling in the gland, including maturation at neonatal age, adaptation to physiological demands, regeneration upon injury and growth of local tumors. Although functions of pituitary stem cells are slowly but gradually uncovered, their regulation largely remains virgin territory. Since postnatal stem cells in general reiterate embryonic developmental pathways, attention is first being given to regulatory networks involved in pituitary embryogenesis. Here, we give an overview of the current knowledge on the NOTCH, WNT, epithelial-mesenchymal transition, SHH and Hippo pathways in the pituitary stem/progenitor cell compartment during various (activation) conditions from embryonic over neonatal to adult age. Most information comes from expression analyses of molecular components belonging to these networks, whereas functional extrapolation is still very limited. From this overview, it emerges that the 'big five' embryonic pathways are indeed reiterated in the stem cells of the 'lazy' homeostatic postnatal pituitary, further magnified en route to activation in more energetic, physiological and pathological remodeling conditions. Increasing the knowledge on the molecular players that pull the regulatory strings of the pituitary stem cells will not only provide further fundamental insight in postnatal pituitary homeostasis and activation, but also clues toward the development of regenerative ideas for improving treatment of pituitary deficiency and tumors.

Androgen receptor in cancer-associated fibroblasts influences stemness in cancer cells

Androgen receptor (AR) regulation pathways are essential for supporting the growth and survival of prostate cancer cells. Recently, sub-populations of prostate cancer cells have been identified with stem cell features and are associated with the emergence of treatment-resistant prostate cancer. Here, we explored the function of AR in prostate cancer-associated fibroblasts (CAFs) relative to growth and stem cell-associated characteristics. CAFs were isolated from the murine cPten^-/-L prostate cancer model and cultured with human prostate cancer epithelial (hPCa) cells. A murine-specific AR antisense oligonucleotide (ASO) was used to suppress the expression of AR in the CAF cells. CAFs express low, but significant levels of AR relative to fibroblasts derived from non-malignant tissue. CAFs promoted growth and colony formation of hPCa cells, which was attenuated by the suppression of AR expression. Surprisingly, AR-depleted CAFs promoted increased stem cell marker expression in hPCa cells. Interferon gamma (IFN-γ) and macrophage colony-stimulating factor (M-CSF) were increased in AR-depleted CAF cells and exhibited similar effects on stem cell marker expression as seen in the CAF co-culture systems. Clinically, elevated IFN-γ expression was found to correlate with histologic grade in primary prostate cancer samples. In summary, AR and androgen-dependent signaling are active in CAFs and exert significant effects on prostate cancer cells. IFN-γ and M-CSF are AR-regulated factors secreted by CAF cells, which promote the expression of stem cell markers in prostate cancer epithelial cells. Understanding how CAFs and other constituents of stromal tissue react to anti-cancer therapies may provide insight into the development and progression of prostate cancer.