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.     

miR-139-5p is a regulator of metastatic pathways in breast cancer

Metastasis is a complex, multistep process involved in the progression of cancer from a localized primary tissue to distant sites, often characteristic of the more aggressive forms of this disease. Despite being studied in great detail in recent years, the mechanisms that govern this process remain poorly understood. In this study, we identify a novel role for miR-139-5p in the inhibition of breast cancer progression. We highlight its clinical relevance by reviewing miR-139-5p expression across a wide variety of breast cancer subtypes using in-house generated and online data sets to show that it is most frequently lost in invasive tumors. A biotin pull-down approach was then used to identify the mRNA targets of miR-139-5p in the breast cancer cell line MCF7. Functional enrichment analysis of the pulled-down targets showed significant enrichment of genes in pathways previously implicated in breast cancer metastasis (P < 0.05). Further bioinformatic analysis revealed a predicted disruption to the TGFβ, Wnt, Rho, and MAPK/PI3K signaling cascades, implying a potential role for miR-139-5p in regulating the ability of cells to invade and migrate. To corroborate this finding, using the MDA-MB-231 breast cancer cell line, we show that overexpression of miR-139-5p results in suppression of these cellular phenotypes. Furthermore, we validate the interaction between miR-139-5p and predicted targets involved in these pathways. Collectively, these results suggest a significant functional role for miR-139-5p in breast cancer cell motility and invasion and its potential to be used as a prognostic marker for the aggressive forms of breast cancer.     

基于生物信息学分析研究miR-182-5p通过靶向调控EP300促进乳腺癌细胞的侵袭和转移

近期研究表明,miR-182-5p对多种癌症的侵袭和转移具有重要作用,但其在乳腺癌侵袭转移中的研究相对较少。本研究通过网上在线microRNA分析工具下载乳腺癌组织及正常乳腺组织表达比较的数据集,分析发现在GSE4589、GSE38167、GSE61438等3个数据库中,在乳腺癌组织中存在26个相同的microRNA,其中8个上调,而我们实验验证发现hsa-miR-182在8例病理组织中的表达上调差异最显著(P=0.001),选定目的基因hsa-miR-182;qRT-PCR检测细胞中miR-182-5p的表达,结果显示,与MCF-10A相比,miR-182-5p在MDA-MB-231、T47D、MDA-MB-453、MCF-7中表达上调(P<0.05);转染miR-182-5p干扰质粒,qRT-PCR检测细胞中miR-182-5p的表达情况。结果显示,miR-182-5p表达显著降低(P=0.003),提示转染成功;Transwell侵袭结果显示,MDAMB-231细胞敲低miR-182-5p,与对照组相比,体外侵袭能力明显降低(P=0.002);Western印迹检测转染miR-182-5p干扰质粒时,MDA-MB-231中上皮-间质转化(epithelial-mesenchymal transition,EMT)相关标志物的表达情况,结果显示,与对照组相比,敲低miR-182-5p使细胞中上皮-钙黏着蛋白(E-cadherin)表达上调,神经-钙黏着蛋白(N-cadherin)、波形蛋白(vimentin)表达下调。为研究探讨miR-182-5p的靶蛋白,采用在线预测软件预测可能与miR-182-5p结合的靶蛋白,cytoscape构建蛋白质互作网络图并筛选出hub基因;双荧光素酶结果证实,miR-182-5p可与EP300靶向结合(P=0.001);采用qRT-PCR、Western印迹检测转染miR-182-5p干扰质粒后EP300在mRNA及蛋白质水平的表达,结果显示,与对照组相比,在敲低miR-182-5p组中EP300在mRNA及蛋白质的表达上调(P=0.001)。综上所述,miR-182-5p可靶向调节EP300,促进乳腺癌细胞的侵袭与转移。     

RBP-J promotes cell growth and metastasis through regulating miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis in colorectal cancer

BackgroundRBP-J is involved in number of cellular processes. However, the potential mechanisms of RBP-J on colorectal cancer (CRC) development have not been clearly defined. In this study, we aimed to investigate the role and molecular mechanism of RBP-J in CRC.MethodsThe expression levels of RBP-J and Tiam1 in CRC tissues and cells were evaluated by RT-qPCR or western blot. RBP-J was knocked down with sh-RBP-J or overexpressed by pcDNA3.1-RBP-J in CRC cells. Cell proliferation, migration and invasion abilities were analyzed by MTT, wound healing, and transwell assay, respectively. CHIP-qPCR, RIP and dual luciferase reporter assays were performed to confirm the interaction between miR-182-5p and RBP-J or Tiam1. Expression levels of p-p38 MAPK, p38 MAPK, Slug-1, Twist1 and MMP-9 were analyzed by western blot. G-LISA test was used to detect Rac1 activity.ResultsOur results showed that the expression of RBP-J and Tiam1 was significantly up-regulated in CRC tissues and cells. RBP-J overexpression promoted proliferation, migration and invasion of CRC cells. Moreover, RBP-J was found to directly target miR-182-5p promoter and positively regulate the Tiam1/Rac1/p38 MAPK signaling pathway in CRC cells. It was also proved that miR-182-5p can bind Tiam1 directly. Furthermore, experiments revealed that RBP-J could promote CRC cell proliferation, migration and invasion via miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis. In addition, knockdown of RBP-J reduced tumor growth and metastasis in CRC mice.ConclusionRBP-J regulates CRC cell growth and metastasis through miR-182-5p mediated Tiam1/Rac1/p38 MAPK signaling pathway, implying potential novel therapeutic targets for CRC patients.     

MicroRNA-630 inhibits breast cancer progression by directly targeting BMI1

MicroRNAs (miRNAs) play critical roles in breast cancer cell biological processes, including proliferation and apoptosis by inhibiting the expression of their target genes. Herein, we reported that miR-630 overexpression initiates apoptosis, blocks cell cycle progression and suppresses cell proliferation in breast cancer cells. Furthermore, BMI1, a member of polycomb group family, was identified as a direct target of miR-630, and there was a negative correlation between the expression levels of BMI1 and miR-630 in human breast cancer samples. With a series of biology approaches, subsequently, we proved that BMI1 was a functional downstream target of miR-630 and mediated the property of miR-630-dependent inhibition of breast cancer progression. Taken together, these findings provide further evidence on the tumor-suppression function of miR-630 in breast cancer, and clarify BMI1 as a novel functional target gene of miR-630.     

MicroRNA-488-3p inhibits proliferation and induces apoptosis by targeting ZBTB2 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the eighth most prevalent cancer and the sixth leading cause for cancer-associated mortality. MicroRNAs (miRNAs) are increasingly reported to exert important regulatory functions in human cancers by regulating certain gene expression. miR-488-3p has been identified to be a tumor suppressor in multiple cancers, but its role in ESCC is yet to be investigated. The present study aimed to uncover the biological role and modulatory mechanism of miR-488-3p in ESCC. We first revealed the downregulation of miR-488-3p in ESCC tissues and cell lines. Gain-of-function assays confirmed that miR-488-3p overexpression abrogated proliferation and accelerated apoptosis. Mechanistically, we identified via bioinformatics tool and confirmed that zinc finger and BTB domain containing 2 (ZBTB2) was a target for miR-488-3p. Moreover, miR-488-3p activated the p53 pathway through suppressing ZBTB2. Finally, rescue assays proved that ZBTB2 was involved in the regulation of miR-488-3p on proliferation and apoptosis in ESCC. Additionally, we verified that miR-488-3p had alternate targets in ESCC by confirming the involvement of protein kinase, DNA-activated, catalytic subunit (PRKDC), a known target for miR-488-3p, in miR-488-3p-mediated regulation on ESCC. In sum, this study revealed that miR-488-3p inhibited proliferation and induced apoptosis by targeting ZBTB2 and activating p53 pathway in esophageal squamous cell carcinoma, providing a novel biological target for ESCC.     

Resveratrol chemosensitizes adriamycin-resistant breast cancer cells by modulating miR-122-5p

Breast cancer is one of the major malignancies threatening women's health worldwide, and chemotherapy tolerance has become a severe limitation of clinical treatment. Recent findings have revealed that resveratrol, as a dietary agent with antitumour activity, could prevent cancer progression by regulating microRNAs (miRNAs). Additionally, dysregulated miRNAs have been found to contribute significantly to chemoresistance by an increasing number of studies. In this study, experiments were designed to study the functional role of resveratrol in MCF-7 cells (low-invasive breast cancer) in chemosensitivity to adriamycin and to determine the targeted miRNAs of resveratrol and their key target proteins linked to cell activity. We demonstrated that in resveratrol-induced chemosensitivity, cell cycle and apoptosis were arrested in adriamycin-resistant breast cancer cells after modulation of the critical suppresser, miR-122-5p. Further miRNA modulation with miR-122-5p mimics or miR-122-5p inhibitors indicated a major effect of miR-122-5p on the regulation of key antiapoptotic proteins (B-cell lymphoma 2 [Bcl-2]) and cyclin-dependent kinases (CDK2, CDK4, and CDK6) in drug-resistant breast cancer cells in response to resveratrol. In conclusion, our results indicate that resveratrol acts as a potential inducer to enhance the chemosensitivity of breast cancer and also suggest that miR-122-5p is involved in the pathway of cell-cycle arrest by targeting Bcl-2 and CDKs.     

miR-219-5p targets TBXT and inhibits breast cancer cell EMT and cell migration and invasion

miR-219-5p has been reported to act as either a tumor suppressor or a tumor promoter in different cancers by targeting different genes. In the present study, we demonstrated that miR-219-5p negatively regulated the expression of TBXT, a known epithelial–mesenchymal transition (EMT) inducer, by directly binding to TBXT 3′-untranslated region. As a result of its inhibition on TBXT expression, miR-219-5p suppressed EMT and cell migration and invasion in breast cancer cells. The re-introduction of TBXT in miR-219-5p overexpressing cells decreased the inhibitory effects of miR-219 on EMT and cell migration and invasion. Moreover, miR-219-5p decreased breast cancer stem cell (CSC) marker genes expression and reduced the mammosphere forming capability of cells. Overall, our study highlighted that TBXT is a novel target of miR-219-5p. By suppressing TBXT, miR-219-5p plays an important role in EMT and cell migration and invasion of breast cancer cells.     

Multiple types of noncoding RNA are involved in potential modulation of PTTG1's expression and function in breast cancer

Breast cancer is a malignant type with morbidity ranking the first of women globally. As widely acknowledged, there exist close links between ncRNA-mRNA axis and breast cancer. In this study, we first overviewed expression and prognostic values of pituitary tumor transforming gene (PTTGs) in breast cancer. Next, two binding miRNAs (miR-186-5p and miR-655-3p) of PTTG1 in breast cancer were identified. Subsequently, several potential upstream ncRNAs of PTTG1-miR-186-5p/miR-655-3p axis in breast cancer were successively screened out, consisting of 11 lncRNAs, 17 circRNAs and 12 pseudogene-derived RNAs. Enrichment analysis for downstream target genes of PTTG1-miR-186-5p/miR-655-3p axis revealed that this axis is associated with TGF-beta signaling and MAPK signaling pathways. Further investigation demonstrated AURKA was one of the most key hub genes. Collectively, we established a potential PTTG1-related ncRNA-mRNA regulatory network in breast cancer.     

miR-188-5p suppresses cellular proliferation and migration via IL6ST: A potential noninvasive diagnostic biomarker for breast cancer

Previously, serum miR-188-5p is differentially expressed in breast cancer, but the diagnostic potential of circulating miR-188-5p as well as its regulatory mechanism in breast cancer remain uncertain. Herein, serum miR-188-5p was detected by real-time polymerase chain reaction in patients with breast cancer, breast fibroadenoma, and healthy subjects. Circulating miR-188-5p was abnormally elevated in patients with breast cancer as compared with these other two groups, and was reduced in patients with breast cancer following surgical treatment. Increased serum miR-188-5p corresponded to lymph node metastasis status and TNM stages of breast cancer. A receiver operating characteristic curve analysis of the ability to circulate miR-188-5p to distinguish between patients with breast cancer and either noncancerous patients or patients with breast fibroadenoma yielded corresponding areas under the curve of 0.894 and 8.814. miR-188-5p was downregulated in the highly malignant cancer line MDA-MB-231 relative to the less malignant MCF-7 cells. In vitro, functional analyses conducted via transfecting cells with mimics and inhibitors revealed miR-188-5p to suppress breast cancer cell proliferation and migration, which was mediated by its downstream target IL6ST. Comparison of intracellular and exosomal miR-188-5p levels indicated that miR-188-5p was selectively sorted into exosomes derived from MDA-MB-231 cells rather than those from MCF-7 cells. However, exosomal miR-188-5p levels in the serum of patients with breast cancer were reduced compared to healthy controls and did not differ relative to patients with breast fibroadenoma. In summary, miR-188-5p acts in a tumor-suppressive manner in breast cancer progression and may serve as a noninvasive early diagnostic biomarker and therapeutic target in breast cancer.     

Tumour-suppressive microRNA-424-5p directly targets CCNE1 as potential prognostic markers in epithelial ovarian cancer

An accumulated evidence supports that MicroRNAs (miRNAs) have shown a prominent role in pathological processes and different tumor onset. However, to date, the potential functional roles and molecular mechanisms by how microRNA-424-5p(miR-424-5p) affects cancer cell proliferation are greatly unclear, especially in epithelial ovarian cancer(EOC).In this study, we demonstrated that miR-424-5p was significantly down-regulated in EOC tissues and cell lines. The level of miR-424-5p was negatively correlated with tumor size, TNM stage, pathological grade, lymphatic metastasis of EOC. Restoring miR-424-5p expression in EOC cells dramatically suppressed cell proliferation and caused an accumulation of cells in G1 phase, and thus contributed to better prognosis of EOC patients. Mechanistically, miR-424-5p inhibits CCNE1 expression through targeting CCNE1 3′UTR, and subsequent arrest cell cycle in G1/G0 phase by inhibiting E2F1-pRb pathway. This study revealed functional and mechanistic links between miR-424-5p and CCNE1 in the progression of EOC and provide an important insight into that miR-424-5p may serve as a therapeutic target in EOC.     

MicroRNA-195-5p suppresses glucose uptake and proliferation of human bladder cancer T24 cells by regulating GLUT3 expression

It has been reported that expression of glucose transporter member 3 (GLUT3) is up-regulated in bladder cancers. However, the regulating mechanism remains unknown. Here, we assessed whether microRNAs (miRNAs) regulate GLUT3 expression in bladder cancers. In our study, miR-195-5p was identified to directly targeted GLUT3 3'-untranslated region (UTR) in bladder cancer T24 cells. Small interfering RNA (siRNA)- and miR-195-5p-mediated GLUT3 knockdown experiments revealed that miR-195-5p decreased T24 cells glucose uptake, inhibited cell growth and promoted cell apoptosis through suppression of GLUT3 expression. Therefore, miR-195-5p is a novel and also the first identified miRNA that targets GLUT3, and the aberrant decreased expression of miR-195-5p and consequent GLUT3 up-regulation may contribute to bladder carcinogenesis.