Tumorigenesis Of Bladder Cancer Research Articles

MicroRNA-328-3p inhibits the tumorigenesis of bladder cancer through targeting ITGA5 and inactivating PI3K/AKT pathway.

Previous studies have shown that microRNA-328-3p (miR-328-3p) is involved in tumorigenesis of many human cancers. However, the specific function of miR-328-3p remains unclear in bladder cancer (BC). Therefore, this research was designed to investigate the role of miR-328-3p in BC. Expressions of miR-328-3p and integrin α5 (ITGA5) were measured by quantitative Real-time polymerase chain reaction (qRT-PCR). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and transwell assays were used to explore the function of miR-328-3p in BC. The expression of the corresponding genes was observed via Western blot and immunocytochemical assays. The dual luciferase assay was applied to verify the relationship between miR-328-3p and ITGA5. Tumor growth was measured via xenograft tumor formation assay. Downregulation of miR-328-3p was identified in BC tissues, which predicted poor prognosis in BC patients. Moreover, miR-328-3p suppressed cell proliferation, migration and invasion in BC through targeting ITGA5. Furthermore, miR-328-3p inhibited epithelial-mesenchymal transition (EMT) and inactivated PI3K/AKT pathway in BC. Besides that, miR-328-3p was found to inhibit tumor growth of BC. MiR-328-3p inhibited tumorigenesis of BC through targeting ITGA5 and inactivating the PI3K/AKT pathway.

MEX3C regulates lipid metabolism to promote bladder tumorigenesis through JNK pathway.

Purpose: Bladder cancer (BC) is the most common urinary cancer among men with a high rate of deaths despite the improved medical technology and treatment. Recent evidence demonstrated that Mex-3 RNA-Binding Family Member C (MEX3C) plays various roles in different biological activities, but its molecular mechanisms underlying the pathogenesis of BC remain unclear yet. The aim of this research was to explore the expression patterns of MEX3C and its biological functions in human BC.Materials and methods: The Cancer Genome Atlas (TCGA) and Oncomine databases were jointly used to analyze the expression of MEX3C in BC and its correlation with the clinicopathological features, while real-time PCR and immunohistochemistry analysis were used to verify the predicted results. Wound-healing assay, Matrigel invasion assay, BODIPY staining and Western blot analysis were used in a cell model to assess the effect of MEX3C on the lipid metabolism, invasion and migration of BC and its mechanisms.Results: MEX3C was highly expressed in BC tissues and cells compared with their normal counterparts, and its expression was positively correlated with the clinicopathological features, especially the invasiveness phenotype. Overexpression of MEX3C accumulated lipid droplets and promoted cell adhesion, invasion and migration. We further demonstrated that MEX3C regulated lipid metabolism and promoted tumor development and progression through activation of JNK signaling and upregulating the JNK downstream protein levels of sterol regulatory element-binding proteins-1, fatty acid synthase and acetyl-CoA carboxylase-1.Conclusion: Here we identified MEX3C as a new oncogene to promote bladder tumorigenesis by regulating lipid metabolism through Mitogen-activated protein kinase/c-Jun N-terminal kinase (MAPK/JNK) pathway. These findings suggest a new role of MEX3C in promoting BC tumorigenesis and provide a novel biomarker or molecular target for diagnosis or treating BC.

Characterization of mRNA Expression and Endogenous RNA Profiles in Bladder Cancer Based on The Cancer Genome Atlas (TCGA) Database.

BackgroundBladder cancer is a multifactorial disease with increasing incidence and mortality. Genetic alterations and altered expressions of mRNAs, long non-coding RNAs (lncRNAs), and miRNAs have been shown to play important roles in the tumorigenesis of bladder cancer. However, the functions of key RNAs and their regulatory network in bladder cancer are still to be elucidated.Material/MethodsRNA profiles were downloaded from The Cancer Genome Atlas (TCGA) database. The differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer were acquired through analyses of data from 414 bladder cancer tissues and 19 normal bladder tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed by using “DAVID6.8” and the R package “ClusterProfile”. Protein–protein interaction and competing endogenous RNA (ceRNA) networks were constructed by using “STRING” database and Cytoscape 3.6.2. Based on the clinical data and Cox regression, a prognosis model was established, and survival analysis was performed.ResultsA total of 1819 mRNAs, 659 lncRNAs, and 160 miRNAs were identified as significantly differentially expressed in bladder cancer of which 52 mRNAs, 58 lncRNAs, and 22 miRNAs were incorporated in the ceRNA network. CFL2 and TPM2 were found to be downregulated and showed significant correlation to each other in bladder cancer. HOXB5 and 6 lncRNAs (ADAMTS9-AS1, AC112721.1, LINC00460, AC110491.1, LINC00163, and HCG22) were strongly associated with high-grade, disease stages, and overall survival.ConclusionsIn this study, we have identified differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer which were strongly associated with oncogenesis and prognosis. Further experimental studies are necessary to validate these results.

PPARγ inhibition regulates the cell cycle, proliferation and motility of bladder cancer cells.

Peroxisome proliferator‐activated receptor gamma (PPARγ) is a member of the nuclear receptor family of ligand‐activated transcription factors and plays an important role in regulating cell proliferation, inflammation and lipid and glucose homeostasis. Our results revealed that PPARγ was up‐regulated in human bladder cancer (BCa) tissues both at transcriptional and translational levels. Moreover, down‐regulation of PPARγ mRNA or inhibition of PPARγ function (using GW9662, antagonist of PPARγ) could significantly suppress the proliferation of BCa cells. Furthermore, the cell cycle arrested in G0/G1 phase was also induced by the down‐regulated PPARγ possibly through AKT‐mediated up‐regulation of p21/p27, whereas no significant transformation of apoptosis was observed. In addition, knockdown or inhibition of PPARγ might reduce the invasion and migration of BCa cells by affecting epithelial‐mesenchymal transition‐related proteins through AKT/GSK3β signalling pathway. Additionally, in vivo studies showed that BCa cell proliferation was significantly suppressed by GW9662. In conclusion, our results indicated that PPARγ might be crucial for BCa tumorigenesis by interfering with the motility and viability of BCa cells.

LncRNA and Gene expression profiling of human bladder cancer

Bladder cancer (BC) is the most common urologic neoplasms with a high rate of recurrence. The development of BC is a complex process, resulting from somke, drugs or bladder inflammation. However, the uinderlying mechanisms of BC tumorigenesis remained unclear. In this study, we performed RNA sequencing of three paired para-tumor and tumor tissuses from BC patients. Compared with para-tumor tissuses, BC tissues displayed 1136 upregulated and 1199 downregualted lncRNAs, and 1347 upregulated and 953 downregualted genes. Additionally, the common upregulated genes were mainly enriched in SNARE interactions, amino sugar and nucleotide sugar metabolism and antigen processing pathways. The common downregulated genes were mainly focused amino acid metabolism and drug meabolism signalings. More importantly, cytokine related genes were highly expressed in BC, which suggest that the dysregulation of immunoregulatory process and amino acid metabolism played a crucial role in the oncogenesis of BC.

MicroRNA‑663b downregulation inhibits proliferation and induces apoptosis in bladder cancer cells by targeting TUSC2.

The present study aimed to explore the role and underlying molecular mechanism of microRNA‑663b (miR‑663b) in the tumorigenesis of bladder cancer. The miR‑663b expression in human bladder cancer tissues and cell lines was measured determined reverse transcription‑quantitative polymerase chain reaction. TargetScan was used to predict the potential targets of miR‑663b, and a dual‑luciferase reporter assay was performed to validate tumor suppressor candidate 2 (TUSC2) as a target of miR‑663b. Cell Counting Kit‑8 was used for cell viability analysis, and cell apoptosis was evaluated by flow cytometry. In addition, western blot analysis was performed to detect protein expression in current study. The findings suggested that miR‑663b was upregulated in bladder cancer tissues and cell lines compared with normal tissue and cells. TUSC2 was validated as a direct target of miR‑663b and was negatively regulated by miR‑663b. miR‑663b inhibition significantly reduced the viability of T24 cells, and T24 cell apoptosis was markedly induced. In addition, miR‑663b inhibition enhanced the expression levels of p53 and p21 in T24 cells. Furthermore, the changes caused by miR‑663b inhibitor in T24 cells were eliminated by TUSC2 gene silencing. In conclusion, inhibition of miR‑663b reduced viability and induced apoptosis in bladder cancer cells by targeting TUSC2. These findings provide a promising novel therapeutic target for bladder cancer treatment.

Low Expression of hsa_circ_0018069 in Human Bladder Cancer and Its Clinical Significance.

Abnormal expression of noncoding RNA molecules such as circRNA plays an important role in the development of malignant tumors. circRNAs are stable in structure and can be useful as ideal tumor markers. Advanced bladder cancer has poor treatment options and prognosis. Thus, we examined circRNAs to further understand the pathogenesis and development of bladder cancer and to identify molecular markers for the early diagnosis of bladder carcinoma. We found that hsa_circ_0018069 was differentially expressed in our RNA sequencing data. We used qRT-PCR to detect its expression in T24 and Biu-87 cell lines and in 41 paired samples of bladder cancer and adjacent normal tissue and analyzed the correlation between expression of hsa_circ_0018069 and the clinical characteristics of patients with bladder cancer. We then performed a bioinformatics analysis to reveal the mechanism of hsa_circ_0018069 in tumorigenesis of bladder cancer. The expression of hsa_circ_0018069 was significantly reduced in T24 and Biu-87 cells and was also significantly downregulated in bladder cancer tissues. Decreased expression of hsa_circ_0018069 was related to the grade stage (P=0.024), T stage (P=0.027), and muscular invasion depth (P=0.022) of bladder cancer. Bioinformatics analysis showed that hsa_circ_0018069 was coexpressed with protein-coding mRNAs that participate in cytoskeletal protein binding and cell-substrate junction assembly and play an anticancer role through focal adhesion and calcium signaling pathways. ceRNA analysis showed that hsa_circ_0018069 functions in ErbB, Ras, FoxO, and the focal adhesion signaling pathway by harboring miR-23c, miR-34a-5p, miR-181b-5p, miR-454-3p, and miR-3666. hsa_circ_0018069 may thus play an important role in the occurrence and progression of bladder cancer and serve as a valuable biomarker for the early diagnosis of this disease.

MiR-182-5p affects human bladder cancer cell proliferation, migration and invasion through regulating Cofilin 1

BackgroundHuman bladder cancer is one of the common malignant tumors, and it mainly occurs in men. miR-182-5p, a member of miR-183 family, acts as tumor suppressor or oncogene in various kinds of tumors. In this study, we first investigate that the absence of miR-182-5p in human bladder cancer promotes tumor growth by regulating the expression of Cofilin 1, an actin modulating-protein.MethodsHuman bladder tumor tissue specimens were collected to detect the expression of miR-182-5p and Cofilin 1 by qRT-PCR. Luciferase activity assay was performed to demonstrate the regulation of Cofilin 1 mRNA 3′UTR by miR-182-5p. Then, cell experiments were performed to analysis the effect of miR-182-5p/Cofilin 1 pathway on tumor cell proliferation, migration, invasion and colony forming efficiency. Finally, xenograft tumor models were established to evaluate the role of miR-182-5p in tumorigenesis abilities in vivo.ResultsqRT-PCR and Western blotting analysis showed that Cofilin 1 expression was up-regulated in both bladder cancer tissues and cell lines compared with normal. Luciferase activity assay showed that miR-182-5p specifically targets Cofilin 1 mRNA 3′UTR and represses the expression of Cofilin 1. Also, miR-182-5p inhibited bladder tumor cell proliferation, migration, invasion and colony forming efficiency. Furthermore, xenograft tumor model assay showed that miR-182-5p plays a negative role in bladder cancer tumorigenesis abilities in vivo.ConclusionPresent results suggest that miR-182-5p could inhibit human bladder tumor growth by repressing Cofilin 1 expression. Our findings may provide a new horizon for exploring therapeutic target of bladder cancer.

Dynamic m6A mRNA methylation reveals the role of METTL3-m6A-CDCP1 signaling axis in chemical carcinogenesis

N6-methyladenosine (m6A) is the most abundant internal modification in mammalian mRNAs. Despite its functional importance in various physiological events, the role of m6A in chemical carcinogenesis remains largely unknown. Here we profiled the dynamic m6A mRNA modification during cellular transformation induced by chemical carcinogens and identified a subset of cell transformation-related, concordantly modulated m6A sites. Notably, the increased m6A in 3′-UTR mRNA of oncogene CDCP1 was found in malignant transformed cells. Mechanistically, the m6A methyltransferase METTL3 and demethylases ALKBH5 mediate the m6A modification in 3′-UTR of CDCP1 mRNA. METTL3 and m6A reader YTHDF1 preferentially recognize m6A residues on CPCP1 3′-UTR and promote CDCP1 translation. We further showed that METTL3 and CDCP1 are upregulated in the bladder cancer patient samples and the expression of METTL3 and CDCP1 is correlated with the progression status of the bladder cancers. Inhibition of the METTL3-m6A-CDCP1 axis resulted in decreased growth and progression of chemical-transformed cells and bladder cancer cells. Most importantly, METTL3-m6A-CDCP1 axis has synergistic effect with chemical carcinogens in promoting malignant transformation of uroepithelial cells and bladder cancer tumorigenesis in vitro and in vivo. Taken together, our results identify dynamic m6A modification in chemical-induced malignant transformation and provide insight into critical roles of the METTL3-m6A-CDCP1 axis in chemical carcinogenesis.

The circINTS4/miR-146b/CARMA3 axis promotes tumorigenesis in bladder cancer.

Accumulating evidence shows that circular RNAs (circRNAs) function as microRNA sponges that regulate gene expression in the progression of human cancers. However, the roles of circRNAs and functional miRNA sponges in bladder cancer (BC) remain largely unknown. In the present study, we applied bioinformatics methods and hypothesised that miR-146b may target the 3'-untranslated region (UTR) of CARMA3 mRNA and circINTS4 may serve as a sponge for miR-146b in BC tumorigenesis. Expression of circINTS4 was significantly increased in miR-146b-downregulated BC tissues and cell lines compared to adjacent normal tissues. Furthermore, circINTS4 was found to control multiple pathological processes, including cell proliferation and migration, the cell cycle and apoptosis. Regarding the mechanism, circINTS4 directly bound to miR-146b to inhibit its activity of targeting the 3'-UTR of CARMA3 mRNA. In addition, circINTS4 could activate the NF-kB signalling pathway and suppress the P38 MAPK signalling pathway in a CARMA3-mediated manner in BC cells. In summary, the circINTS4/miR-146b/CARMA3 axis might serve as a promising therapeutic target for BC intervention.

HnRNP-F Regulates EMT in Bladder Cancer by Mediating the Stabilization of Snail mRNA Through Binding to Its 3'UTR

Background: Heterogeneous nuclear ribonucleoprotein F (HnRNP-F) has previously been implicated in multiple cancers, suggesting its roles in tumorigenesis, but the potential oncogenic role and mechanism of hnRNP-F in bladder cancer (BC) remains incompletely understood. Methods: HnRNP-F was identified by proteomic methods. A correlation of hnRNP-F expression with the prognosis was analyzed in103 BC patients. Then, we applied in vitro and in vivo methods to reveal the behaviors of hnRNP-F in BC tumorigenesis. Furthermore, the interaction between hnRNP-F and Snail mRNA was examined by RNA immunopreciptiation (RIP), and Snail mRNA stability was measured after treatment with actinomycin D. Finally, the binding domain between hnRNP-F and Snail mRNA was tested through Snail mRNA truncations and mutants. Finding: HnRNP-F is significantly up-regulated in BC tissue, and its increased expression is associated with poor prognosis in BC patients. HnRNP-F was necessary for tumor growth, inducing Epithelial-mesenchymal transition (EMT) and metastasis in BC. The changes of Snail expression were positively consistent with hnRNP-F in both mRNA and protein levels when hnRNP-F was silenced or enhanced, suggesting that Snail is likely to be the downstream target of hnRNP-F that mediates its effects on enhancing invasion, metastasis and EMT in BC. Overexpression of hnRNP-F caused an increase in the stability of the Snail mRNA was enhanced. Our RNA chip analysis revealed that hnRNP-F could combine with the Snail mRNA, and we further demonstrated that hnRNP-F could directly bind to the 3'untranslated region (3'UTR) of Snail mRNA to enhance its stability. Interpretation: Our findings suggest that hnRNP-F mediates the stabilization of Snail mRNA via binding to its 3'UTR, subsequently regulating EMT. Funding Statement: This study was supported by Natural Science Foundation Committee of China (NSFC 81802941) (F.L.), and the Natural Science Foundation of Guangdong Province of China (2018A0303130287) (F.L.). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: All patients were given written informed consent and all procedures were approved by bioethics committee of the authors' hospital.

Increased expression of TRIP13 drives the tumorigenesis of bladder cancer in association with the EGFR signaling pathway.

Thyroid hormone receptor interactor 13 (TRIP13) is a crucial regulator of the spindle apparatus checkpoint and double-stranded break repair. The abnormal expression of TRIP13 was recently found in several human cancers, whereas the role of TRIP13 in the development of bladder cancer (BCa) has not been fully elucidated. Here, we reported that TRIP13 expression was elevated in BCa tissues compared with normal bladder tissues. Notably, the increased expression of TRIP13 was correlated with advanced tumor stage, lymph node metastasis, distant metastasis and reduced survival in BCa patients. Knockdown of TRIP13 in bladder cancer cells suppressed proliferation, induced cell cycle arrest, promoted apoptosis, and impaired cell motility, ultimately inhibiting tumor xenograft growth. Mechanistic investigations revealed that TRIP13 directly bound to epidermal growth factor receptor (EGFR), modulating the EGFR signaling pathway. Furthermore, TRIP13 expression was positively correlated with EGFR expression in BCa specimens, and the high expression of both TRIP13 and EGFR predicted poor survival. Overall, our results underscore the crucial role of TRIP13 in the tumorigenesis of BCa and provide a novel biomarker and therapeutic target for BCa treatment.

Specifically blocking the fatty acid synthesis to inhibit the malignant phenotype of bladder cancer

Fatty acid synthesis is regulated by transcription factors SREBPs and their escort protein SCAP. Malignant cells become dependent on de novo lipogenesis, which sustains rapid proliferation and resistance to cellular stress. Increasing evidence showed SCAP participated in various disease processes including malignant tumors, which regulate transcription factors SREBPs Tumorigenesis is associated with incur glucose consumption and lipogenesis. In our study, we discovered that SCAP was upregulated in BC tissues. SCAP knockdown by CRISPR-Cas9 inhibit the cell proliferation, invasion and migration. Additionally, the cell apoptosis was facilitated. What's more, downregulation of SCAP could weaken the cancer-promoting effects of estrogen on BC. Our study revealed that SCAP played a carcinogenic role in BC and lipogenesis might promote the initiation of BC by inducing SCAP. Thus, Targeting SCAP may provide a promising means of treating BC and a new perspective for the tumorigenesis of bladder cancer.

Thyrotroph embryonic factor is downregulated in bladder cancer and suppresses proliferation and tumorigenesis via the AKT/FOXOs signalling pathway.

ObjectivesThyrotroph embryonic factor (TEF) plays an important role in several different processes in normal human cells; however, its function in malignant cells has not been fully elucidated.Materials and methodsThe mRNA levels of TEF in 408 bladder cancer (BC) samples from the Cancer Genome Atlas (TCGA) database were analysed in depth. Next, the expression of TEF in 7 BC cell lines was compared to that in normal bladder epithelial cells. The cell count, colony formation and anchorage‐independent growth assays as well as a nude mouse xenograft model were utilized to examine the effects of TEF on proliferation and tumorigenesis. Immunofluorescence staining, flow cytometry analysis and treatment with an AKT inhibitor were performed to explore the molecular regulation mechanisms of TEF in BC.ResultsAnalysis of TCGA data indicated that TEF mRNA was decreased in BC samples compared to that in normal bladder epithelial cells and correlated with the poor survival of BC patients. Additional experiments verified that the mRNA and protein expression of TEF were significantly decreased in BC cells compared to that in normal bladder epithelial cells. Upregulation of TEF expression significantly retarded BC cell growth by inhibiting the G1/S transition via regulating AKT/FOXOs signalling.ConclusionOur results suggest that TEF might play an important role in suppressing BC cells proliferation and tumorigenesis.

IC-2 Suppresses Proliferation and Induces Apoptosis of Bladder Cancer Cells via the Wnt/β-Catenin Pathway

BackgroundThe Wnt/β-catenin signaling pathway participates in many important tumorigeneses processes, including bladder cancer. The inhibition of abnormal activation of Wnt pathways might provide a new approach to tumor treatment. In the present study, we investigated the role of IC-2, a novel Wnt pathways small molecular inhibitor, in bladder cancer tumorigenesis.Material/MethodsBladder cancer cells were treated with various concentrations of IC-2 (0–5 μM) in vitro. The proliferation ability was measured using colony formation assay and apoptosis was measured using flow cytometry analysis. The protein expression was detected using Western blot analysis. Xenograft in vivo assay was performed to assess tumor growth.ResultsIC-2 suppressed the proliferation and aggravated the apoptosis of bladder cancer cells in dose-dependent and time-dependent manners in vitro. Moreover, high concentrations of IC-2 inhibited the Wnt pathway-related protein expression levels, including β-catenin, Cyclin D1, and TCF4. In vivo, administration of IC-2 in xenograft mice decreased the β-catenin expression and reduced the tumor volume.ConclusionsOur results validate the tumor-inhibition effect of IC-2 on bladder cancer in vivo and in vitro, providing a novel therapeutic strategy for bladder cancer.

C/EBPβ promotes the viability of human bladder cancer cell by contributing to the transcription of bladder cancer specific lncRNA UCA1

Urothelial Carcinoma Antigen 1 (UCA1) is a cell and tissue specific long non-coding RNA (lncRNA) associated with the tumorigenesis and invasion of bladder cancer. However, the mechanism driving the over-transcription of UCA1 in bladder cancer cells remains unclear. It has been reported that C/EBPβ has a significant role of regulation in tumorigenesis. Here we report that the expression of UCA1 was dramatically inhibited in 5637 cells with C/EBPβ down-regulation. Additionally, the function tests indicated that C/EBPβ could promote 5637 cells growth and colony formation by inducing the expression level of UCA1. These data suggest that C/EBPβ was involved in transcriptional regulation of UCA1 and contributed substantially to its high expression and proliferation promoting in bladder cancer cells.

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.

Long noncoding RNA neuroblastoma-associated transcript 1 gene inhibits malignant cellular phenotypes of bladder cancer through miR-21/SOCS6 axis

Bladder cancer (BC) is one of the most common tumors in the urinary system. Noncoding RNAs are considered to take part in cellular phenotypes and are emerging as diagnostic and prognostic biomarkers of BC. The aim of this study is to investigate the clinical significance of neuroblastoma- associated transcript 1 (NBAT1) gene and its effects on malignant cellular phenotypes in BC. NBAT1 gene was low-expressed in BC tissues and cell lines and its low-expression was related with high pathological grade and metastasis of BC. Upregulation of NBAT1 gene depressed cell viability and invasiveness of KK47 and T24 cells and arrested KK47 and T24 cells at G1 stage. In addition, NBAT1 could target silence the expression of miR-21-5p in RNA-induced silencing complex-dependent manner. KK47 and T24 cells with miR-21-5p knockdown showed reduced cell viability, G1-stage arrest, and depressed invasiveness. MiR-21-5p mediates the regulatory effects of NBAT1 on malignant cellular phenotypes of BC cells. Moreover, SOCS6 gene was a target gene of miR-21-5p, and miR-21-5p modulated malignant cellular phenotypes of KK47 and T24 cells through targeted silencing of SOCS6. In conclusion, low-expression of NBAT1 is associated with the progress and metastasis of BC, and NBAT1 inhibits malignant cellular phenotypes through miR-21-5p/SOCS6 axis in BC. Our findings help to elucidate the tumorigenesis of BC, and future study will provide a novel therapeutic target for BC.

MiR-203a functions as a tumor suppressor in bladder cancer by targeting SIX4.

Increasing evidence indicates that microRNAs (miRNAs) have essential roles in various biological processes, including proliferation, migration, invasion, cell cycle progression and apoptosis. It is considered that miRNA de-regulation contributes to tumor progression and metastasis in various cancers, and MiR-203a has been identified as a tumor suppressor in cancers, such as glioma, gastric cancer and hepatocellular carcinoma. Herein, we established that miR-203a expression is significantly lower in bladder cancer tissues than in adjacent normal tissues, and that low miR-203a expression is associated with poor patient outcome. The over-expression of miR-203a inhibited bladder cancer cell proliferation, invasion, migration and EMT in vitro, and its up-regulation led to bladder cancer cell cycle arrest and apoptosis. This over-expression also inhibited the PI3K/Akt signaling pathway. Bioinformatics prediction software and luciferase reporter assay then confirmed that SIX4 is a direct target of miR-203a. We established negative correlation between SIX4 expression and miR-203a expression in bladder cancer tissues, and SIX4 silencing caused effects similar to miR-203a up-regulation Furthermore, SIX4 over-expression diminished the effects of miR-203a on bladder cancer cells in vitro. In summary, our study determined that miR-203a down-regulation is closely related to tumorigenesis in bladder cancer; thus suggesting that miR-203a is a potential prognostic marker and a potential target in bladder cancer treatment.

Oestrogen promotes tumorigenesis of bladder cancer by inducing the enhancer RNA-eGREB1.

In recent years, studies have shown that enhancer RNAs (eRNAs) can be transcribed from enhancers. Increasing evidence has revealed that eRNAs play critical roles in the development of various cancers. Oestrogen‐associated eRNAs are closely related to breast cancer. In view of the gender differences in bladder cancer (BCa), we suppose that oestrogen‐associated eRNAs are also involved in tumorigenesis of BCa. In our study, we first demonstrated that eGREB1 derived from the enhancer of an oestrogen‐responsive gene—GREB1 was up‐regulated in BCa tissues, and the expression level of eGREB1 is positively associated with the histological grade and TNM stage of BCa. Knockdown of eGREB1 by CRISPR‐Cas13a could inhibit cell proliferation, migration and invasion and induce apoptosis in BCa cells T24 and 5637. Besides, we exhibited the promoting effect of oestrogen on BCa cells. What's more, down‐regulation of eGREB1 could improve the malignant biological characteristics of BCa cells induced by oestrogen. In conclusion, our data indicated that eGREB1 plays oncogenic role and oestrogen may promote the occurrence and progression of BCa by inducing eGREB1 production. Our findings provide new insights into the prevention of BCa and develop a novel therapeutic target for the treatment of BCa.