Circular RNA circ-VANGL1 as a competing endogenous RNA contributes to bladder cancer progression by regulating miR-605-3p/VANGL1 pathway

Increasing reports indicate that circular RNAs (circRNAs) are very important regulators in human diseases, including cancers. In bladder cancer (BC), several circRNAs have been reported to be involved in tumor progressions, such as circ-ITCH and circTCF25. However, the functions of most circRNAs in BC still remains largely unknown. In this study, we identified a novel circRNA termed as circ-VANGL1 by bioinformatics analysis. We found that circ-VANGL1 was highly expressed in BC tissues compared with adjacent normal tissues. Furthermore, we showed that circ-VANGL1 could serve as a prognostic marker for patients with BC. Through functional experiments, we found that circ-VANGL1 knockdown significantly suppressed BC cell proliferation, cell cycle, migration, and invasion in vitro. Besides, circ-VANGL1 silence inhibited BC cell propagation in vivo. Mechanistically, we identified circ-VANGL1 as a sponge of miR-605-3p which targeted VANGL1 in BC cells. Through repressing miR-605-3p availability, circ-VANGL1 contributes to VANGL1 expression, consequently leading to BC cell proliferation, migration, and invasion. Taken together, our study demonstrated circ-VANGL1/miR-605-3p/VANGL1 as a novel essential signaling pathway involved in BC progression.     

Retracted: LncRNA MT1JP functions as a tumor suppressor via regulating miR-214-3p expression in bladder cancer

Growing evidence suggested that the long noncoding RNAs (lncRNAs) regulate several pathophysiological processes in tumorigenesis and may be new biomarkers for tumor therapy. In this study, we studied the expression and role of lncRNA MT1JP in the development of bladder cancer. We demonstrated that the expression of MT1JP was downregulated in bladder tumor samples and cell lines. Ectopic expression of MT1JP suppressed cell proliferation, cycle, and invasion in bladder cancer. In addition, our result suggested that miR-214-3p overexpression decreased the luciferase activity of wild-type MT1JP but not mutated-type MT1JP and elevated expression of MT1JP decreased miR-214-3p expression in the bladder cancer cell. Furthermore, we indicated that the expression of miR-214-3p was upregulated in bladder tumor samples and cell lines. Ectopic expression of miR-214-3p promoted cell proliferation, cycle, and invasion in bladder cancer. MT1JP suppressed cell proliferation, cycle, and invasion via negative modulation of miR-214-3p in bladder cancer. These data suggested that lncRNA MT1JP acts a tumor suppressor gene in bladder cancer progression, considering MT1JP as a new therapeutic target in bladder cancer.     

MicroRNA-1280 Inhibits Invasion and Metastasis by Targeting ROCK1 in Bladder Cancer

MicroRNAs (miRNAs) are non-protein-coding sequences that can function as oncogenes or tumor suppressor genes. This study documents the tumor suppressor role of miR-1280 in bladder cancer. Quantitative real-time PCR and in situ hybridization analyses showed that miR-1280 is significantly down-regulated in bladder cancer cell lines and tumors compared to a non-malignant cell line or normal tissue samples. To decipher the functional significance of miR-1280 in bladder cancer, we ectopically over-expressed miR-1280 in bladder cancer cell lines. Over-expression of miR-1280 had antiproliferative effects and impaired colony formation of bladder cancer cell lines. FACS (fluorescence activated cell sorting) analysis revealed that re-expression of miR-1280 in bladder cancer cells induced G2-M cell cycle arrest and apoptosis. Our results demonstrate that miR-1280 inhibited migration and invasion of bladder cancer cell lines. miR-1280 also attenuated ROCK1 and RhoC protein expression. Luciferase reporter assays demonstrated that oncogene ROCK1 is a direct target of miR-1280 in bladder cancer. This study also indicates that miR-1280 may be of diagnostic and prognostic importance in bladder cancer. For instance, ROC analysis showed that miR-1280 expression can distinguish between malignant and normal bladder cancer cases and Kaplan-Meier analysis revealed that patients with miR-1280 high expression had higher overall survival compared to those with low miR-1280 expression. In conclusion, this is the first study to document that miR-1280 functions as a tumor suppressor by targeting oncogene ROCK1 to invasion/migration and metastasis. Various compounds are currently being used as ROCK1 inhibitors; therefore restoration of tumor suppressor miR-1280 might be therapeutically useful either alone or in combination with these compounds in the treatment of bladder cancer.     

MicroRNA-133b suppresses bladder cancer malignancy by targeting TAGLN2-mediated cell cycle

MicroRNAs (miRNAs), a group of small noncoding RNAs, are widely involved in the regulation of gene expression via binding to complementary sequences at 3′-untranslated regions (3′-UTRs) of target messenger RNAs. Recently, downregulation of miR-133b has been detected in various human malignancies. Here, the potential biological role of miR-133b in bladder cancer (BC) was investigated. In this study, we found the expression of miR-133b was markedly downregulated in BC tissues and cell lines (5637 and T24), and was correlated with poor overall survival. Notably, transgelin 2 (TAGLN2) was found to be widely upregulated in BC, and overexpression of TAGLN2 also significantly increased risks of advanced TMN stage. We further identified that upregulation of miR-133b inhibited glucose uptake, invasion, angiogenesis, colony formation and enhances gemcitabine chemosensitivity in BC cell lines by targeting TAGLN2. Additionally, we showed that miR-133b promoted the proliferation of BC cells, at least partially through a TAGLN2-mediated cell cycle pathway. Our results suggest a novel miR-133b/TAGLN2/cell cycle pathway axis controlling BC progression; a molecular mechanism which may offer a potential therapeutic target.     

Oncogenic miRNA-182-5p Targets Smad4 and RECK in Human Bladder Cancer

Onco-miR-182-5p has been reported to be over-expressed in bladder cancer (BC) tissues however a detailed functional analysis of miR-182-5p has not been carried out in BC. Therefore the purpose of this study was to: 1. conduct a functional analysis of miR-182-5p in bladder cancer, 2. assess its usefulness as a tumor marker, 3. identify miR-182-5p target genes in BC. Initially we found that miR-182-5p expression was significantly higher in bladder cancer compared to normal tissues and high miR-182-5p expression was associated with shorter overall survival in BC patients. To study the functional significance of miR-182-5p, we over-expressed miR-182-5p with miR-182-5p precursor and observed that cell proliferation, migration and invasion abilities were increased in BC cells. However cell apoptosis was inhibited by miR-182-5p. We also identified Smad4 and RECK as potential target genes of miR-182-5p using several algorithms. 3′UTR luciferase activity of these target genes was significantly decreased and protein expression of these target genes was significantly up-regulated in miR-182-5p inhibitor transfected bladder cancer cells. MiR-182-5p also increased nuclear beta-catenin expression and while Smad4 repressed nuclear beta-catenin expression. In conclusion, our data suggests that miR-182-5p plays an important role as an oncogene by knocking down RECK and Smad4, resulting in activation of the Wnt-beta-catenin signaling pathway in bladder cancer.     

The lncRNA ELF3-AS1 promotes bladder cancer progression by interaction with Krüppel-like factor 8

Accumulating evidence has shown the critical role of long non-coding RNAs (lncRNAs) during cancer progression. However, the involvement of ELF3-AS1 in bladder cancer (BC) remains largely unclear. By lncRNA profiling, we identified ELF3-AS1 as a novel oncogenic lncRNA during bladder cancer development. ELF3-AS1 was highly expressed in bladder cancer and correlated with poor prognosis. ELF3-AS1 could increase viability and migration of bladder cancer cells in vitro and promoted xenograft tumor growth in vivo. Furthermore, ELF3-AS1 could interact with KLF8 to stabilize KLF8 by protecting it from proteasome-mediated degradation. KLF8 in turn could bind ELF3-AS1 promoter and transactivate ELF3-AS1 expression. The positive feedback loop between ELF3-AS1 and KLF8 enhanced KLF8 signaling by increasing MMP9 expression. Collectively, our study has unraveled a novel mechanism of ELF3-AS1-mediated oncogenesis in bladder cancer by reinforcement of ELF3-AS1/KLF8 signaling with potential implications for therapeutic intervention.     

Breast cancer stem cell-derived extracellular vesicles transfer ARRDC1-AS1 to promote breast carcinogenesis via a miR-4731-5p/AKT1 axis-dependent mechanism

ObjectivesDeregulation of long non-coding RNAs (lncRNAs) has been frequently reported in breast cancer (BC). This goes to show the importance of understanding its significant contribution towards breast carcinogenesis. In the present study, we clarified a carcinogenic mechanism based on the ARRDC1-AS1 delivered by breast cancer stem cells-derived extracellular vesicles (BCSCs-EVs) in BC.MethodsThe isolated and well characterized BCSCs-EVs were co-cultured with BC cells. The expression of ARRDC1-AS1, miR-4731-5p, and AKT1 was determined in BC cell lines. BC cells were assayed for their viability, invasion, migration and apoptosis in vitro by CCK-8, Transwell and flow cytometry, as well as tumor growth in vivo after loss- and gain-of function assays. Dual-luciferase reporter gene, RIP and RNA pull-down assays were performed to determine the interactions among ARRDC1-AS1, miR-4731-5p, and AKT1.ResultsElevation of ARRDC1-AS1 and AKT1 as well as miR-4731-5p downregulation were observed in BC cells. ARRDC1-AS1 was enriched in BCSCs-EVs. Furthermore, EVs containing ARRDC1-AS1 enhanced the BC cell viability, invasion and migration and glutamate concentration. Mechanistically, ARRDC1-AS1 elevated the expression of AKT1 by competitively binding to miR-4731-5p. ARRDC1-AS1-containing EVs were also found to enhance tumor growth in vivo.ConclusionCollectively, BCSCs-EVs-mediated delivery of ARRDC1-AS1 may promote the malignant phenotypes of BC cells via the miR-4731-5p/AKT1 axis.     

Hsa_circRNA_0088036 acts as a ceRNA to promote bladder cancer progression by sponging miR-140-3p

Circular RNAs (circRNAs) are a class of non-coding RNAs that play vital roles in cancer biology. However, the potential role of hsa_circRNA_0088036 in bladder cancer (BCa) remains unknown. Hsa_circRNA_0088036 was identified by microarray analysis and validated by quantitative real-time polymerase chain reaction. Functional assays were conducted to confirm the effects of hsa_circRNA_0088036 on the growth, migration, invasion, tumorigenesis, and metastasis of BCa cells. The luciferase reporter assay and RNA pull down assay were performed to investigate the interactions between hsa_circRNA_0088036, miR-140-3p, and forkhead box protein Q1 (FOXQ1). Upregulated expression of hsa_circRNA_0088036 in BCa tissues and cell lines was positively correlated with overall survival and clinicopathologic characteristics. Knockdown of hsa_circRNA_0088036 inhibited the growth, migration, and invasion of BCa cells both in vivo and in vitro. Mechanistically, hsa_circRNA_0088036 could directly interact with miR-140-3p and act as a miRNA sponge to modulate FOXQ1 expression. Knockdown of hsa_circRNA_0088036 inhibited the proliferation, migration, and metastasis of BCa cells via miR-140-3p/FOXQ1 signaling, suggesting that hsa_circRNA_0088036 is a potential biomarker and therapeutic target for BCa.Subject terms: Bladder cancer, Long non-coding RNAs     

miR-29b regulates migration of human breast cancer cells

microRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by targeting mRNAs, inhibiting the expression of the associated proteins. Although a role for aberrant miRNA expression in cancer has been postulated, the pathophysiologic role and relevance of aberrantly expressed miRNAs in tumor biology has not been established. We evaluated the expression pattern of miRNAs in human breast cancer cells by qPCR, finding out an up-regulated miRNA miR-29b and studying its biological effect by migration assay. We defined a target gene PTEN by bioinformatics approach and western blot. In breast cancer cell line MDA-MB-231 cell, which migrate faster than MCF-7, we observed that miR-29b was highly over-expressed. Inhibition of miR-29b in cultured cells increased the expression of the phosphatase and tensin homolog (PTEN) tumor suppressor, promoting apoptosis, decreasing migration, and decreasing invasion. In contrast, enhanced miR-29b expression by transfection with pre-miR-29b decreased the expression of PTEN and impaired apoptosis, increasing tumor cell migration and invasion. Moreover, PTEN was shown to be a direct target of miR-29b and was also shown to contribute to the miR-29b-mediated effects on cell invasion. Modulation of miR-29b altered the role of PTEN involved in cell migration and invasion. Aberrant expression of miR-29b, which modulates PTEN expression, can contribute to migration, invasion, and anti-apoptosis.     

Global microRNA expression profiling identifies MiR-210 associated with tumor proliferation, invasion and poor clinical outcome in breast cancer

Purpose

Aberrant microRNA (miRNA) expression is associated with cancer and has potential diagnostic and prognostic value in various malignancies. In this study, we investigated miRNA profiling as a complementary tool to improve our understanding of breast cancer (BC) biology and to assess whether miRNA expression could predict clinical outcome of BC patients.

Experimental Design

Global miRNA expression profiling using microarray technology was conducted in 56 systemically untreated BC patients who had corresponding mRNA expression profiles available. Results were further confirmed using qRT-PCR in an independent dataset of 89 ER-positive BC patients homogeneously treated with tamoxifen only. MiR-210 functional analyses were performed in MCF7 and MDA-MB-231 BC cell lines using lentiviral transduction.

Results

Estrogen receptor (ER) status, tumor grade and our previously developed gene expression grade index (GGI) were associated with distinct miRNA profiles. Several miRNAs were found to be clinically relevant, including miR-210, its expression being associated with tumor proliferation and differentiation. Furthermore, miR-210 was associated with poor clinical outcome in ER-positive, tamoxifen-treated BC patients. Interestingly, the prognostic performance of miR-210 was similar to several reported multi-gene signatures, highlighting its important role in BC differentiation and tumor progression. Functional analyses in BC cell lines revealed that miR-210 is involved in cell proliferation, migration and invasion.

Conclusions

This integrated analysis combining miRNA and mRNA expression demonstrates that miRNA expression provides additional biological information beyond mRNA expression. Expression of miR-210 is linked to tumor proliferation and appears to be a strong potential biomarker of clinical outcome in BC.     

MicroRNA-409-3p inhibits migration and invasion of bladder cancer cells via targeting c-Met

There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may contribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3′-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.     

Cyclin-dependent kinase 4 is a novel target in micoRNA-195-mediated cell cycle arrest in bladder cancer cells

miRNAs are a class of small-noncoding RNAs capable of negatively regulating gene expression. Here, we found that miR-195 is down-regulated in human bladder cancer tissue versus normal adjacent tissue. To better characterize the role of miR-195 in bladder cancer, we conducted gain of function analysis by transfecting bladder cancer cell line T24 with chemically synthesized miR-195 mimic. We identified CDK4, an early G1 cell cycle regulator, as a novel target of miR-195. Selective over-expression of miR-195 could induce G1-phase arrest in T24 cells, and subsequently inhibit T24 cell growth. These findings indicate that miR-195 could be a potential tumor suppressor in bladder cancer.     

Overexpressed MicroRNA-182 Promotes Proliferation and Invasion in Prostate Cancer PC-3 Cells by Down-Regulating N-myc Downstream Regulated Gene 1 (NDRG1)

MicroRNAs, non-coding 20–22 nucleotide single-stranded RNAs, result in translational repression or degradation and gene silencing of their target genes, and significantly contribute to the regulation of gene expression. In the current study, we report that miR-182 expression was significantly upregulated in prostate cancer tissues and four cell lines, compared to benign prostatic hyperplasia tissues and normal prostatic epithelial (RWPE-1) cells. Ectopic overexpression of miR-182 significantly promotes the proliferation, increases the invasion, promotes the G1/S cell cycle transition and reduces early apotosis of PC-3 cells, while suppression of miR-182 decreased the proliferation and invasion, inhibits the G1/S cell cycle transition and increase early apotosis of PC-3 cells. Additionally, we demonstrated that miR-182 could downregulate expression of NDRG1 by directly targeting the NDRG1 3′-untranslated region. In conclusion, our results suggest that miR-182 plays an important role in the proliferation of human prostate cancer cells by directly suppressing the tumor supressor gene NDRG1. We uncovered a new epigenetic regulation of NDRG1.