Advances in intravesical therapy for the treatment of non-muscle invasive bladder cancer (Review)

Bladder cancer selective chemotherapy with potent NQO1 substrate co-loaded prodrug nanoparticles

Currently, clinical intravesical instillation chemotherapy has been greatly compromised by the toxicological and physiological factors. New formulations that can specifically and efficiently kill bladder cancer cells are in urgent need to overcome the low residence efficiency and dose limiting toxicity of current ones. The combination of mucoadhesive nanocarriers and cancer cell selective prodrugs can to great extent address these limitations. However, the insignificant endogenous stimulus difference between cancer cells and normal cells in most cases and the high local drug concentration make it essential to develop new drugs with broader selectivity-window. Herein, based on the statistically different NQO1 expression between cancerous and normal bladder tissues, the reactive oxygen species (ROS) activatable epirubicin prodrug and highly potent NQO1 substrate, KP372-1, was co-delivered using a GSH-responsive mucoadhesive nanocarrier. After endocytosis, epirubicin could be promptly activated by the NQO1-dependent ROS production caused by KP372-1, thus specifically inhibiting the proliferation of bladder cancer cells. Since KP372-1 is much more potent than some commonly used NQO1 substrates, for example, β-lapachone, the cascade drug activation could occur under much lower drug concentration, thus greatly lowering the toxicity in normal cells and broadening the selectivity-window during intravesical bladder cancer chemotherapy.

Hybrid Nanoparticles as an Efficient Porphyrin Delivery System for Cancer Cells to Enhance Photodynamic Therapy

Photodynamic therapy (PDT) is a potential non-invasive approach for application in oncological diseases, based on the activation of a photosensitizer (PS) by light at a specific wavelength in the presence of molecular oxygen to produce reactive oxygen species (ROS) that trigger the death tumor cells. In this context, porphyrins are interesting PS because they are robust, have high chemical, photo, thermal, and oxidative stability, and can generate singlet oxygen (1O2). However, porphyrins exhibit low solubility and a strong tendency to aggregate in a biological environment which limits their clinical application. To overcome these challenges, we developed hybrid nanostructures to immobilize 5,10,15,20-tetrakis[(4-carboxyphenyl) thio-2,3,5,6-tetrafluorophenyl] (P), a new third-generation PS. The biological effect of this system was evaluated against bladder cancer (BC) cells with or without light exposition. The nanostructure composed of lipid carriers coated by porphyrin-chitosan (P-HNP), presented a size of ca. 130 nm and low polydispersity (ca. 0.25). The presence of the porphyrin-chitosan (P-chitosan) on lipid nanoparticle surfaces increased the nanoparticle size, changed the zeta potential to positive, decreased the recrystallization index, and increased the thermal stability of nanoparticles. Furthermore, P-chitosan incorporation on nanoparticles increased the stability and enhanced the self-organization of the system and the formation of spherical structures, as observed by small-angle X-ray scattering (SAXS) analysis. Furthermore, the immobilization process maintained the P photoactivity and improved the photophysical properties of PS, minimizing its aggregation in the cell culture medium. In the photoinduction assays, the P-HNP displayed high phototoxicity with IC50 3.2-folds lower than free porphyrin. This higher cytotoxic effect can be correlated to the high cellular uptake of porphyrin immobilized, as observed by confocal images. Moreover, the coated nanoparticles showed mucoadhesive properties interesting to its application in vivo. Therefore, the physical and chemical properties of nanoparticles may be relevant to improve the porphyrin photodynamic activity in BC cells.

Desloratadine, a Novel Antigrowth Reagent for Bladder Cancer

Desloratadine, a potent antagonist for human histamine H1 receptor, has been revealed to exhibit antihistaminic activity and anti-inflammatory activity. However, it is not yet known whether desloratadine has any effect on the biological behaviors of tumor cells. In this study, we aimed to investigate the effects of desloratadine on cell growth and invasion in bladder cancer EJ and SW780 cells in vitro. We observed that desloratadine inhibited cell viability of EJ and SW780 cells in a dose- and time-dependent manner. Desloratadine treatment was also revealed to suppress colony-formation ability and induce cell cycle arrest at G1 phase in EJ cells. Desloratadine promoted cell apoptosis via modulating the expression of Bcl-2, Bax, cleaved caspase 3, and cleaved caspase 9 in EJ and SW780 cells. Western blot resulted showed that desloratadine also impaired the expression of autophagy-related proteins, such as Beclin 1, P62, and LC3I/II in EJ and SW780 cells; while autophagy inhibitor LY294002 reversed the effects of desloratadine on these proteins. Moreover, desloratadine remarkably attenuated cell migration and invasion. Furthermore, we illustrated that desloratadine downregulated the expression of N-cadherin, Vimentin, Snail1, and Snail2, while upregulated the expression of E-cadherin in EJ and SW780 cells in vitro. The level of interleukin 6 was reduced in desloratadine-treated cells, while upregulation of interleukin 6 significantly abolished the anticancer activity of desloratadine in cell invasion and Bcl-2, Bax, Beclin1, LC3-I/II, N-cadherin, and E-cadherin expression in EJ cells. Taken together, our data suggest a potential anticancer activity of desloratadine on cell growth and invasion for bladder cancer, which may be mediated by diminishing the epithelial-to-mesenchymal transition and interleukin 6.

Novel anticancer therapy in BCG unresponsive non-muscle-invasive bladder cancer

INTRODUCTION

Many patients with non-muscle-invasive bladder cancer (NMIBC) failed intravesical BCG therapy. Currently, radical cystectomy is the recommended standard of care for those patients. There is unfortunately no effective other second-line therapy recommended.

AREAS COVERED

In this review, we present the topics of BCG unresponsive NMIBC; definition, prognosis, and further treatment options: immunotherapy, intravesical chemotherapy, gene therapy, and targeted individualized therapy.

EXPERT OPINION

There are major challenges of the management of NMIBC who failed BCG therapy as many patients refuse or are unfit for radical cystectomy. Multiple new modalities currently under investigation in ongoing clinical trials to better treat this category of patients. Immunotherapy, especially PD-1/PD-L1 inhibitors, offers exciting and potentially effective strategies for the treatment of BCG unresponsive NMIBC. As the data expands, it is sure that soon there will be established new guidelines for NMIBC.

Chromatin-regulatory genes served as potential therapeutic targets for patients with urothelial bladder carcinoma

Urothelial bladder carcinoma is the ninth most common cancer in the world, with an estimated 150,000 deaths per year. Two comprehensive analysis based on The Cancer Genome Atlas urothelial bladder carcinoma reported that chromatin modifier gene mutations were common in bladder cancer. We aimed to find how the mutations and transcriptional profiles of the genes involving in chromatin modification affected the prognosis of patients. The data were retrieved from the Genomic Data Commons data portal and the gene list in pathway Chromatin Modifying Enzymes were obtained from Reactome. The expression levels and mutational profiles of the genes involving in the chromatin were utilized altogether to construct a fusion patient similarity network by similarity network fusion. The genes that were differentially expressed in one clustered group or two were identified. Fifty chromatin-regulating genes had nonsilent mutations in at least 10 patients. KMT2D, KDM6A, CREBBP, ARID1A, and ARID2 had enriched inactivating mutations. Among 399 cases where both the single-nucleotide polymorphism information and the messenger RNA expression profiles were available, 326, 23, and 50 patients were clustered into Groups 1, 2, and 3, respectively. The survival analysis suggested that the patients in these three groups had a different prognosis. Thity-one genes were identified as differentially expressed in any group. The Gene Ontology term enrichment showed that the differentially expressed genes were enriched in the immune response especially in the complement activation. Altogether, chromatin-regulatory genes were key in bladder cancer and can serve, with the differentially expressed genes, as potential therapeutic targets.

Protein kinase D inhibitor CRT0066101 suppresses bladder cancer growth in vitro and xenografts via blockade of the cell cycle at G2/M

The protein kinase D (PKD) family of proteins are important regulators of tumor growth, development, and progression. CRT0066101, an inhibitor of PKD, has antitumor activity in multiple types of carcinomas. However, the effect and mechanism of CRT0066101 in bladder cancer are not understood. In the present study, we show that CRT0066101 suppressed the proliferation and migration of four bladder cancer cell lines in vitro. We also demonstrate that CRT0066101 blocked tumor growth in a mouse flank xenograft model of bladder cancer. To further assess the role of PKD in bladder carcinoma, we examined the three PKD isoforms and found that PKD2 was highly expressed in eight bladder cancer cell lines and in urothelial carcinoma tissues from the TCGA database, and that short hairpin RNA (shRNA)-mediated knockdown of PKD2 dramatically reduced bladder cancer growth and invasion in vitro and in vivo, suggesting that the effect of the compound in bladder cancer is mediated through inhibition of PKD2. This notion was corroborated by demonstrating that the levels of phospho-PKD2 were markedly decreased in CRT0066101-treated bladder tumor explants. Furthermore, our cell cycle analysis by flow cytometry revealed that CRT0066101 treatment or PKD2 silencing arrested bladder cancer cells at the G2/M phase, the arrest being accompanied by decreases in the levels of cyclin B1, CDK1 and phospho-CDK1 (Thr161) and increases in the levels of p27Kip1 and phospho-CDK1 (Thr14/Tyr15). Moreover, CRT0066101 downregulated the expression of Cdc25C, which dephosphorylates/activates CDK1, but enhanced the activity of the checkpoint kinase Chk1, which inhibits CDK1 by phosphorylating/inactivating Cdc25C. Finally, CRT0066101 was found to elevate the levels of Myt1, Wee1, phospho-Cdc25C (Ser216), Gadd45α, and 14-3-3 proteins, all of which reduce the CDK1-cyclin B1 complex activity. These novel findings suggest that CRT0066101 suppresses bladder cancer growth by inhibiting PKD2 through induction of G2/M cell cycle arrest, leading to the blockade of cell cycle progression.

The role of LIM and SH3 protein-1 in bladder cancer metastasis

The LIM and SH3 protein-1 (LASP-1) is a multi-domain protein that is involved in several malignant cancers. The role of LASP-1 in malignant phenotypes including high invasive properties and unrestricted cell proliferation, remain to be elucidated. The present study reported the association of LASP-1 expression with bladder cancer malignancy and its role in cancer cell invasion and proliferation. The immunohistochemical analysis of the expression status of LASP-1 in radical cystectomy specimens from invasive bladder cancer patients revealed that the LASP-1-positive patients demonstrated a decreased survival rate compared with the LASP-1-negative patients. The expression level of LASP-1 was increased in invasive bladder cancer cell lines compared with the non-invasive bladder cancer cell lines. Invasive cancer cells form invadopodia, the filamentous actin-based membrane protrusions that are essential in cancer cell invasion. Knockdown of LASP-1 reduced the ability to form invadopodia, resulting in decreased invasive capacity of the LASP-1 knockdown cells. In addition, knockdown of LASP-1 reduced cell proliferation. These results suggest that LASP-1 is important in invadopodia formation and cell proliferation of bladder cancer cells, promoting the malignant properties and resulting in poor-prognosis.

Down-regulation of lncRNA CASC2 promotes cell proliferation and metastasis of bladder cancer by activation of the Wnt/β-catenin signaling pathway

Long noncoding RNAs cancer susceptibility candidate 2 (CASC2) have been demonstrated as playing crucial regulatory roles in a few of cancers. However, the biological function of lncRNA CASC2 in bladder cancer are still unclear. In this study, we found that lncRNA CASC2 was significantly down-regulated in bladder cancer tissues and cell lines by quantitative real time-PCR and associated with advanced TNM stage (III/IV). Moreover, overexpression of lncRNA CASC2 remarkably reduced the cell growth, migration and invasion, as well as promoted early apoptosis of bladder cancer cell in vitro. Furthermore, we illustrated that lncRNA CASC2 inhibited Wnt/β-catenin signal pathway activity by decrasing the β-catenin expression and reversing the downstream target gene expression of Wnt signaling pathway. Taken together, lncRNA CASC2 plays an pivotal role in bladder tumorigenesis and progression and may act as a potential biomarker for the treatment of bladder cancer.

Oxymatrine inhibits proliferation of human bladder cancer T24 cells by inducing apoptosis and cell cycle arrest

Oxymatrine has been shown to exert an antitumor effect on several types of cancer cells. However, the role of oxymatrine in bladder cancer has not yet been evaluated. The present study was designed to investigate the potential anti-proliferative effect of oxymatrine on bladder cancer T24 cells and the possible mechanisms involved. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell growth, and the cell morphology was examined using hematoxylin and eosin staining, wrights' staining and electron microscopy. The caspase-3 and survivin mRNA and protein levels were assessed using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of tumor protein p53 (p53), Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2) were analyzed using immunohistochemistry. Oxymatrine inhibited the proliferation of the T24 cells in a dose- and time-dependent manner. Oxymatrine also induced apoptosis and cell cycle arrest in the cells, in association with the upregulation of caspase-3 and Bax, and the downregulation of survivin, Bcl-2 and p53 expression. Overall, oxymatrine inhibits the proliferation of human bladder cancer cells by inducing apoptosis and cell cycle arrest via mechanisms that involve p53-Bax signaling and the downregulation of survivin expression.

Proteomic analysis of proteome and histone post-translational modifications in heat shock protein 90 inhibition-mediated bladder cancer therapeutics

Heat shock protein 90 (HSP90) inhibition is an attractive strategy for cancer treatment. Several HSP90 inhibitors have shown promising effects in clinical oncology trials. However, little is known about HSP90 inhibition-mediated bladder cancer therapy. Here, we report a quantitative proteomic study that evaluates alterations in protein expression and histone post-translational modifications (PTMs) in bladder carcinoma in response to HSP90 inhibition. We show that 5 HSP90 inhibitors (AUY922, ganetespib, SNX2112, AT13387, and CUDC305) potently inhibited the proliferation of bladder cancer 5637 cells in a dose- and time-dependent manner. Our proteomic study quantified 518 twofold up-regulated and 811 twofold down-regulated proteins common to both AUY922 and ganetespib treatment. Bioinformatic analyses revealed that those differentially expressed proteins were involved in multiple cellular processes and enzyme-regulated signaling pathways, including chromatin modifications and cell death-associated pathways. Furthermore, quantitative proteome studies identified 14 types of PTMs with 93 marks on the core histones, including 34 novel histone marks of butyrylation, citrullination, 2-hydroxyisobutyrylation, methylation, O-GlcNAcylation, propionylation, and succinylation in AUY922- and ganetespib-treated 5637 cells. Together, this study outlines the association between proteomic changes and histone PTMs in response to HSP90 inhibitor treatment in bladder carcinoma cells, and thus intensifies the understanding of HSP90 inhibition-mediated bladder cancer therapeutics.

A Hydrogel-Based Epirubicin Delivery System for Intravesical Chemotherapy

This study aimed to examine the efficacy of epirubicin-loaded gelatin hydrogel (EPI-H) in the treatment of superficial urothelium carcinoma. Hydrogel was prepared by Schiff base-crosslinking of gelatin with glutaraldehyde. EPI-H exhibited high entrapment efficiency (59.87% ± 0.51%). EPI-H also increased epirubicin accumulation in AY-27 cells when compared with the effect of aqueous solutions of epirubicin (EPI-AQ); respective epirubicin-positive cell counts were 69.0% ± 7.6% and 38.3% ± 5.8%. EPI-H also exhibited greater cytotoxicity against AY-27 cells than that of EPI-AQ; IC50 values were 13.1 ± 1.1 and 7.5 ± 0.3 μg/mL, respectively. Cystometrograms showed that EPI-H reduced peak micturition, threshold pressures, and micturition duration, and that it increased bladder compliance more so than EPI-AQ. EPI-H enhanced epirubicin penetration into basal cells of urothelium in vivo, whereas EPI-AQ did so only to the umbrella cells. EPI-H inhibited tumor growth upon intravesical instillation to tumor-bearing bladder of F344 rats, inducing higher levels of caspase-3 expression than that observed with EPI-AQ treatment; the number of caspase-3 positive cells in treated urothelium carcinoma was 13.9% ± 4.0% (EPI-AQ) and 34.1% ± 1.0%, (EPI-H). EPI-H has value as an improved means to administer epirubicin in intravesical instillation treatments for bladder cancer.

PLK-1 Silencing in Bladder Cancer by siRNA Delivered With Exosomes

OBJECTIVE

To use exosomes as a vector to deliver small interfering ribonucleic acid (siRNA) to silence the polo-like kinase 1 (PLK-1) gene in bladder cancer cells.

MATERIALS AND METHODS

Exosomes were isolated from both human embryonic kidney 293 (HEK293) cell and mesenchymal stem cell (MSC) conditioned media. Fluorescently labeled exosomes were co-cultured with bladder cancer and normal epithelial cells and uptake was quantified by image cytometry. PLK-1 siRNA and negative control siRNA were loaded into HEK293 and MSC exosomes using electroporation. An invasive bladder cancer cell line (UMUC3) was co-cultured with the electroporated exosomes. Quantitative reverse transcriptase polymerase chain reaction was performed. Protein analysis was performed by Western blot. Annexin V staining and MTT assays were used to investigate effects on apoptosis and viability.

RESULTS

Bladder cancer cell lines internalize an increased percentage of HEK293 exosomes when compared to normal bladder epithelial cells. Treatment of UMUC3 cells with exosomes electroporated with PLK-1 siRNA achieved successful knockdown of PLK-1 mRNA and protein when compared to cells treated with negative control exosomes.

CONCLUSION

HEK293 and MSC exosomes were effectively used as a delivery vector to transport PLK-1 siRNA to bladder cancer cells in vitro, resulting in selective gene silencing of PLK-1. The use of exosomes as a delivery vector for potential intravesical therapy is attractive.

Histone deacetylase inhibitor-induced cell death in bladder cancer is associated with chromatin modification and modifying protein expression: A proteomic approach

The Cancer Genome Atlas (TCGA) project recently identified the importance of mutations in chromatin remodeling genes in human carcinomas. These findings imply that epigenetic modulators might have a therapeutic role in urothelial cancers. To exploit histone deacetylases (HDACs) as targets for cancer therapy, we investigated the HDAC inhibitors (HDACIs) romidepsin, trichostatin A, and vorinostat as potential chemotherapeutic agents for bladder cancer. We demonstrate that the three HDACIs suppressed cell growth and induced cell death in the bladder cancer cell line 5637. To identify potential mechanisms associated with the anti-proliferative and cytotoxic effects of the HDACIs, we used quantitative proteomics to determine the proteins potentially involved in these processes. Our proteome studies identified a total of 6003 unique proteins. Of these, 2472 proteins were upregulated and 2049 proteins were downregulated in response to HDACI exposure compared to the untreated controls (P<0.05). Bioinformatic analysis further revealed that those differentially expressed proteins were involved in multiple biological functions and enzyme-regulated pathways, including cell cycle progression, apoptosis, autophagy, free radical generation and DNA damage repair. HDACIs also altered the acetylation status of histones and non-histone proteins, as well as the levels of chromatin modification proteins, suggesting that HDACIs exert multiple cytotoxic actions in bladder cancer cells by inhibiting HDAC activity or altering the structure of chromatin. We conclude that HDACIs are effective in the inhibition of cell proliferation and the induction of apoptosis in the 5637 bladder cancer cells through multiple cell death-associated pathways. These observations support the notion that HDACIs provide new therapeutic options for bladder cancer treatment and thus warrant further preclinical exploration.

Potential Effect of Liposomes and Liposome-Encapsulated Botulinum Toxin and Tacrolimus in the Treatment of Bladder Dysfunction

Bladder drug delivery via catheter instillation is a widely used treatment for recurrence of superficial bladder cancer. Intravesical instillation of liposomal botulinum toxin has recently shown promise in the treatment of overactive bladder and interstitial cystitis/bladder pain syndrome, and studies of liposomal tacrolimus instillations show promise in the treatment of hemorrhagic cystitis. Liposomes are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core that can encapsulate hydrophilic and hydrophobic drug molecules to be delivered to cells via endocytosis. This review will present new developments on instillations of liposomes and liposome-encapsulated drugs into the urinary bladder for treating lower urinary tract dysfunction.

Intravesical liposome drug delivery and IC/BPS

Intravesical therapy has previously shown to be effective in delaying or preventing recurrence of superficial bladder cancer. This local route of drug administration is now demonstrating promise in the treatment of interstitial cystitis/bladder pain syndrome (IC/BPS) with the benefit of minimal systemic side effects. Liposomes (LPs) are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core. They can incorporate drug molecules, both hydrophobic and hydrophilic, and vastly improve cellular uptake of these drug molecules via endocytosis. Intravesical LPs have therapeutic effects on IC/BPS patients, mainly due to their ability to form a protective lipid film on the urothelial surface and repair the damaged urothelium. This review considers the current status of intravesical LPs and LP mediated drug delivery for the treatment of IC/BPS.

Management of T1 Urothelial Carcinoma of the Bladder: What Do We Know and What Do We Need To Know?

T1 bladder cancer constitutes approximately 25% of incident bladder cancers, and as such carries an important public health impact. Notably, it has a heterogeneous natural history, with large variation in reported oncologic outcomes. Optimal risk-stratification is essential to individualize patient management, targeting those at greatest risk of progression for aggressive therapies such as early cystectomy, while allowing others to safely pursue bladder-preserving approaches including intravesical bacillus Calmette-Guerrin (BCG). Current strategies for diagnosis, risk-stratification, and treatment are imperfect, but emerging technologies and molecular approaches represent exciting opportunities to advance clinical paradigms in management of this disease entity.

Mycotic abdominal aortic aneurysm after adjuvant therapy with bacillus Calmette-Guérin in patients with urothelial bladder cancer: a rare but misinterpreted complication

Bacillus Calmette-Guérin (BCG) therapy is often associated with side effects. The most feared is disseminated sepsis that may occur rarely with the development of mycotic aortic aneurysms. Twenty cases of patients treated with intravesical BCG complicated by mycotic abdominal aortic aneurysm have been reported in the literature, including 2 cases of the present study. Delayed vascular work-up represents a critical aspect. Mycotic aneurysms evidence a rapid progression. Primary care physicians and urologists should be sensitized to recognize unspecified symptoms such as potential clinical manifestations of a mycotic abdominal aortic aneurysm, even several months or years after BCG therapy.

Immunotherapy and Radiation - A New Combined Treatment Approach for Bladder Cancer?

Recently, immunotherapy with checkpoint inhibitors has been showing promise in clinical trials for stage IV bladder cancer. Herein, we review the literature regarding the role for radiation therapy, the role for immunotherapy, and the potential synergy of these treatments combined in bladder cancer. There is ample pre-clinical data in a number of different tumor models, coupled with a growing body of clinical evidence in melanoma and other malignancies to suggest combining radiation and immunotherapy could lead to substantial advances in treatment outcomes for bladder cancer. Yet, these data for bladder cancer remain at the pre-clinical stage, and further study is needed.

High-risk nonmuscle invasive bladder cancer

Please also verify that the expansion of HGT1 is OK as set: The risk of progression for high-grade T1 (HGT1) cancer has been recently established at 21% using updated information on large series and a meta-analysis. These outcomes are better than those classically expected supporting the rule of thirds for HGT1. The main limitation of this subgroup is that most studies are retrospective observational studies, which, compared with randomized controlled trials, are subject to various selection biases, carrying a higher risk of uncontrolled confounding factors, with potential preferential reporting of positive findings.

Association between polymorphisms in the integrin gene predicted microRNA binding sites and bladder cancer risk

Bladder cancer (BC) is the ninth most frequent malignancies in the world and the occurrence of this disease has dramatically increased in recent years. Integrins have been demonstrated to play an important role in the development and progression of BC. However, the association between polymorphisms in integrin genes and BC susceptibility was still unclear. A number of studies mainly focused on polymorphisms in the coding regions of integrin genes previously, while in this study, polymorphisms in the 3' untranslated regions (3'UTR) were investigated in Chinese Han population. According to previous study, seven single-nucleotide polymorphisms (SNPs) in predicted microRNA (miRNA) target sites were chosen as potential targets. And four SNPs including rs11902171, rs2675, rs17664, and rs1062484, were finally examined for their effect on BC risk and clinical prognosis. These four polymorphisms were genotyped by using the high-resolution melting method (HRM) in 317 BC patients with long-time follow-up together with 317 age-matched healthy controls. AC carriers of rs2675 in ITGB5 were associated with an increased risk of BC (OR 1.44, 95% CI 1.02-2.03). No significant relationship was detected between these SNPs and the recurrence-free survival time of overall study population or non-muscle invasive BC subgroups in univariable analysis. In conclusion, rs2675 in miRNA binding sites of ITGB5 might be a potential target for BC susceptibility prediction.

Association detection between genetic variants in the microRNA binding sites of toll-like receptors signaling pathway genes and bladder cancer susceptibility

Bladder cancer (BCa) is the second most common urological malignancy, and the incidence of BCa has dramatically increased recently. Various toll-like receptors (TLRs) signaling pathway proteins were proven to be associated with BCa susceptibility. However, the effect of genetic variants in TLRs signaling pathway genes on risk of BCa has not been elucidated clearly. Previous studies mainly focused on the coding region of target genes, while in this study, polymorphisms in the non-coding region, microRNA (miRNA) binding sites were investigated as potential targets. We used bioinformatics approach to screen 100 BCa related TLRs signaling pathway genes. Candidate polymorphisms were select in this region and 8 polymorphisms were confirmed. Rs72552316, located at the 3'UTR of the TLR7 gene, exhibited significant association with risk of BCa, indicating a strong relationship with decreased risk of BCa (P ≤ 0.0001). Furthermore, no association was detected between all the polymorphisms and recurrence-free survival time of overall study population or non-muscle invasive BCa subgroups. In conclusion, rs72552316 in the miRNA binding sites of TLR7 might contribute to BCa susceptibility, and this finding provided new targets for high BCa risk population screening.