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Purpose: Prostate cancer (PCa) is one of the most diagnosed cancers in men worldwide. Several studies have identified that circular RNAs (circRNAs) have a crucial impact on the biological processes in PCa. Therefore, it is necessary to study the molecular mechanism of circRNAs in tumor progression and metastasis., Methods: RNA interference was used to decrease circHIPK3 and MTDH expression. Overexpression vector was used to increase circHIPK3 and MTDH expression. Luciferase reporter assay were used to detect the relationship between circHIPK3 and miR-448 or between miR-448 and MTDH. MTT assay, colony formation assay and transwell assay were used to measure proliferation and migration of PCa cells., Results: Circular RNA circHIPK3 was significantly increased in PCa tissues and cell lines. And overexpression of circHIPK3 promoted the migration, proliferation, and invasion of PC-3 and 22Rv1 cells, while knockdown of circHIPK3 markedly repressed the above-mentioned series of biological processes. Furthermore, circHIPK3 promoted metadherin (MTDH) expression by sponging miR-448. In vivo experiments, it was also found that overexpression of circHIPK3 significantly promoted tumor growth., Conclusions: Our research shows that circHIPK3 plays a carcinogenic effect in PCa by regulating the miR-448/MTDH axis, indicating that circHIPK3 may be a potential therapeutic target for PCa., (© 2021. Federación de Sociedades Españolas de Oncología (FESEO).)

Prostate cancer (PCa) is one of the major cancers affecting males with high mortality around the world. Recent studies have found that some long noncoding RNAs play a critical part in the cellular processes of PCa. In our study, aberrant expressed lymphoid enhancer-binding factor-1 antisense RNA 1 (LEF1-AS1), microRNA-330-5p (miR-330-5p), and lymphoid enhancer-binding factor-1 (LEF1) were screened out from a microarray database, the role of the novel noncoding RNA regulatory circuitry in the initiation and development of PCa was investigated. LEF1-AS1 and LEF1 were highly expressed while miR-330-5p was poorly expressed in PCa. Following that, the PCa PC-3 cell line was adopted for subsequently experiments, in which the expression of LEF1-AS1 and miR-330-5p was subsequently altered by means of exogenous transfection. After that, the effects of up- or downregulation of LEF1-AS1 and miR-330-5p on epithelial-mesenchymal transition (EMT) and the cell ability for proliferation, invasion, migration in vitro, and tumorigenesis and lymph node metastasis (LNM) in vivo were evaluated. RNA crosstalk revealed that LEF1-AS1 bound to miR-330-5p and LEF1 was the target gene of miR-330-5p. Silenced LEF1-AS1 or elevated miR-330-5p exhibited inhibited EMT processes, reduced ability of proliferation, invasion and migration, coupling with decreased tumorigenesis and LNM in nude mice. The key findings of this study collectively propose downregulation of LEF1-AS1 competing with miR-330-5p to inhibit EMT, invasion and migration of PCa by LEF1 repression., (© 2019 Wiley Periodicals, Inc.)

Retinoblastoma (RB) is a well‑vascularized tumor dependent on angiogenesis. The present study aimed to explore whether microRNA (miR)‑182 regulates cell viability, invasion and angiogenesis in RB via the phosphatidylinositol‑3‑OH kinase (PI3K)/protein kinase B (AKT) signaling pathway and by targeting cell adhesion molecule 2 (CADM2). The expression levels of miR‑182 and CADM2 were initially detected in RB tissues from patients with RB who underwent ophthalmectomy, and normal retinal tissues collected from other trauma patients who underwent eye enucleation. To determine whether CADM2 was targeted by miR‑182, a dual luciferase reporter assay was conducted. Subsequently, Y79 and WERI‑Rb‑1 RB cells were transfected with a miR‑182 mimic or miR‑182 inhibitor, or small interfering RNA against CADM2, in order to investigate the effects of miR‑182 on viability and invasion, which were detected using MTT and Transwell assays, respectively. In addition, to determine whether the regulatory mechanism underlying the effects of miR‑182 was associated with the PI3K/AKT signaling pathway, the expression levels of associated genes were detected by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. A xenograft tumor model in nude mice was also established, in order to evaluate the effects of miR‑182 on tumor growth and angiogenesis. The results indicated that miR‑182 expression was increased and CADM2 expression was reduced in RB tissues; CADM2 was confirmed to be targeted and negatively regulated by miR‑182. When the expression of miR‑182 was downregulated, cell viability, invasion, tumor volume and angiogenesis were significantly decreased. Furthermore, the expression levels of PI3K/AKT signaling pathway‑associated genes were increased in response to miR‑182 overexpression or CADM2 silencing. Taken together, these results suggested that inhibition of miR‑182 may suppress cell viability, invasion and angiogenesis in RB through inactivation of the PI3K/AKT pathway and CADM2 upregulation. This mechanism may reveal a novel potential therapeutic target.

Breast carcinoma is one of the most common types of malignant neoplasms, and is associated with high rates of morbidity and mortality. Altered gene expression is critical in the development of breast cancer. To identify the important differentially expressed genes and microRNAs in breast carcinoma, mRNA (GSE26910, GSE42568, and GSE89116) and microRNA (GSE35412) microarray datasets were downloaded from the Gene Expression Omnibus database. The differentially expressed microRNA expression data were extracted with GEO2R online software. The DAVID online database was used to perform a function and pathway enrichment analysis of the key identified differentially expressed genes. A protein-protein interaction (PPI) network was constructed using the STRING online database, and visualized in Cytoscape software. The effect of the expression level of the key identified genes on overall survival (OS) time was analyzed by using the Kaplan-Meier Plotter online database. Furthermore, the online miRNA databases TargetScan, microT-CDS, and TarBase were used to identify the target genes of the differentially expressed miRNAs. A total of 254 differentially expressed genes were identified, which were enriched in cell adhesion, polysaccharide binding, extracellular region part and ECM-receptor interactions. The PPI network contained 250 nodes and 375 edges. Five differentially expressed genes were found to be significantly negatively correlated with the differentially expressed miRNAs, which were potentially also target genes for miRNAs. Four of the five genes, including AKAP12, SOPB, TCF7L2, COL12A1 and TXNIP were downregulated, and were associated with the OS of patients with breast carcinoma. In addition, a total of 130 differentially expressed miRNAs were identified. In conclusion, these results constitute a novel model for miRNA-mRNA differential expression patterns, and further studies may provide potential targets for diagnosing and understanding the mechanisms of breast carcinoma.

Objective: To investigate the possible function and mechanism of lncRNA SNHG8 in the pathogenesis of endometrial carcinoma., Patients and Methods: We utilized qRT-PCR to detect the expression of SNHG8 in 60 cases of endometrial carcinoma and 25 cases of normal endometrium; after that, the endometrial carcinoma cell lines were screened. SNHG8 was transfected into endometrial carcinoma cells by Lipofectamine and the proliferative activity of cells was detected by cell counting kit-8 (CCK-8) assay. Bioinformatics methods were used to detect the target microRNA. miR-152 is predicted to bind to SNHG8 and target genes of c-MET. Luciferase reporter assay was performed to detect the relative luciferase activity between miR-152 and c-MET, SNHG8. The interactions between SNHG8, miR-152, and c-MET were further verified by transfection of miR-152 mimics, miR-152 mimics + OE-SNHG8, SNHG8 siRNA, and SNHG8 siRNA + miR-152 inhibitor., Results: SNHG8 expression in endometrial carcinoma tissue was significantly higher than that in normal endometrium. After transfection with SNHG8 siRNA, the cell viability of AN3CA cells decreased, whereas the activity of Ishikawa was increased after transfection with SNHG8 overexpression plasmid. Bioinformatics predictions and dual luciferase reporter assay illustrated that SNHG8 was bound to miR-152 and miR-152 targeted on c-MET. In addition, miR-152 mimics inhibited the expression of c-MET, and the inhibitory effect was reversed after SNHG8 overexpression. Silencing SNHG8 reduced c-MET expression, and c-MET expression was reversed after addition of miR-152 inhibitor., Conclusions: SNHG8 is highly expressed in endometrial carcinoma, and SNHG8 targets c-MET through miR-152 to regulate the proliferation of endometrial cancer cells.

The vascular response to pro-atherosclerotic factors is a multifactorial process involving endothelial cells (ECs), macrophages (MACs), and smooth muscle cells (SMCs), although the mechanism by which these cell types communicate with each other in response to environmental cues is yet to be understood. Here, we show that miR-155, which is significantly expressed and secreted in Krüppel-like factor 5 (KLF5)-overexpressing vascular smooth muscle cells (VSMCs), is a potent regulator of endothelium barrier function through regulating endothelial targeting tight junction protein expression. VSMCs-derived exosomes mediate the transfer of KLF5-induced miR-155 from SMCs to ECs, which, in turn, destroys tight junctions and the integrity of endothelial barriers, leading to an increased endothelial permeability and enhanced atherosclerotic progression. Moreover, overexpression of miR-155 in ECs inhibits endothelial cell proliferation/migration and re-endothelialization in vitro and in vivo and thus increases vascular endothelial permeability. Blockage of the exosome-mediated transfer of miR-155 between these two cells may serve as a therapeutic target for atherosclerosis., (Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

The regulation of vascular smooth muscle cell (VSMC) proliferation is an important issue because it has major implications for the prevention of pathological vascular conditions. Using microRNA array screen, we found the expression levels of 200 unique miRNAs in hyperplasic tissues. Among them, miR-200c expression substantially was down-regulated. The objective of this work was to assess the function of miR-200c and SUMOylated Krϋppel-like transcription factor 4 (KLF4) in the regulation of VSMC proliferation in both cultured cells and animal models of balloon injury. Under basal conditions, we found that miR-200c inhibited the expression of KLF4 and the SUMO-conjugating enzyme Ubc9. Upon PDGF-BB treatment, Ubc9 interacted with and promoted the SUMOylation of KLF4, which allowed the recruitment of transcriptional corepressors (e.g., nuclear receptor corepressor (NCoR) and HDAC2) to the miR-200c promoter. The reduction in miR-200c levels led to increased target gene expression (e.g., Ubc9 and KLF4), which further repressed miR-200c levels and accelerated VSMC proliferation. These results demonstrate that induction of a miR-200c-SUMOylated KLF4 feedback loop is a significant aspect of the PDGF-BB proliferative response in VSMCs and that targeting Ubc9 represents a novel approach for the prevention of restenosis., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Esophageal squamous cell carcinoma (ESCC) is the leading malignancy in Huaian, China. Recently, emerging studies have suggested that an aberrant microRNA (miRNA) expression signature exists in ESCC. However, there is discordant information available on specific miRNA expression in patients from different regions. In this study, we identified 12 miRNAs that are differentially expressed in patients with ESCC from Huaian, China. Among these miRNAs that displayed unique miRNA expression signatures, miR-1, miR-29c, miR-100, miR-133a, miR-133b, miR-143, miR-145, and miR-195 were downregulated, and miR-7, miR-21, miR-223, and miR-1246 were upregulated in cancerous tissue compared with the adjacent normal tissue. Bioinformatics analyses identified the major biological processes and signaling pathways that are targeted by these differentially expressed miRNAs. Accordingly, miR-29c, miR-100, miR-133a, and miR-133b were found to be involved in invasion and metastasis of ESCC, and miR-7 and miR-21 were found to be related to the differentiation of ESCC. Thus, our data present new evidence for the important roles of miRNAs in ESCC.