Caprin-1 is a novel microRNA-223 target for regulating the proliferation and invasion of human breast cancer cells

MicroRNAs (miRNAs) are 21–22 nucleotides regulatory small non-coding RNAs that inhibit gene expression by binding to complementary sequences especially the 3’ untranslated region (3’UTR) of mRNA. One miRNA can target many messenger RNAs, leading to a complex metabolic network. Previous studies have shown that miRNA-223 regulates migration and invasion of tumor cells and targets cytoplasmic activation/proliferation-associated protein-1 (Caprin-1). In the present study, we detected the expression of miRNA-223 and Caprin-1 in MCF-7, T-47D and MDA-MB-231 cancer cell lines, and MCF-10A normal breast cell line, and analyzed the role of miRNA-223 in Caprin-1-induced proliferation and invasion of human breast cancer cells. We found that miRNA-223 expression levels are significantly lower in MCF-7, T-47D and MDA-MB-231 cancer cells than in MCF-10A normal breast cells, while Caprin-1 expression is higher in cancer cells than in normal breast cells. The most malignant cancer cell line MDA-MB-231 has the lowest expression of miR-223, but the highest expression of Caprin-1. Further, we found that miR-223 targets the 3’UTR of Caprin-1 miRNA and down-regulates the expression of Caprin-1. We also found that over-expression of Caprin-1 can promote the proliferation and the invasion of breast cancer cells, but miRNA-223 can inhibit the proliferation and the invasion. miRNA-223-induced inhibition can be reversed by ectopic over-expression of Caprin-1. These findings suggest that miR-223 may suppress the proliferation and invasion of cancer cells by directly targeting Caprin-1. Our study also indicates that expression levels of miR-223 and Caprin-1 can be used to predict the state of cancer in breast cancer patient.     

MicroRNA-31 functions as an oncogenic microRNA in mouse and human lung cancer cells by repressing specific tumor suppressors

MicroRNAs (miRNAs) regulate gene expression. It has been suggested that obtaining miRNA expression profiles can improve classification, diagnostic, and prognostic information in oncology. Here, we sought to comprehensively identify the miRNAs that are overexpressed in lung cancer by conducting miRNA microarray expression profiling on normal lung versus adjacent lung cancers from transgenic mice. We found that miR-136, miR-376a, and miR-31 were each prominently overexpressed in murine lung cancers. Real-time RT-PCR and in situ hybridization (ISH) assays confirmed these miRNA expression profiles in paired normal-malignant lung tissues from mice and humans. Engineered knockdown of miR-31, but not other highlighted miRNAs, substantially repressed lung cancer cell growth and tumorigenicity in a dose-dependent manner. Using a bioinformatics approach, we identified miR-31 target mRNAs and independently confirmed them as direct targets in human and mouse lung cancer cell lines. These targets included the tumor-suppressive genes large tumor suppressor 2 (LATS2) and PP2A regulatory subunit B alpha isoform (PPP2R2A), and expression of each was augmented by miR-31 knockdown. Their engineered repression antagonized miR-31–mediated growth inhibition. Notably, miR-31 and these target mRNAs were inversely expressed in mouse and human lung cancers, underscoring their biologic relevance. The clinical relevance of miR-31 expression was further independently and comprehensively validated using an array containing normal and malignant human lung tissues. Together, these findings revealed that miR-31 acts as an oncogenic miRNA (oncomir) in lung cancer by targeting specific tumor suppressors for repression.     

Let-7a mimic attenuates CCL18 induced breast cancer cell metastasis through Lin 28 pathway

BackgroundMicroRNAs are believed to influence breast cancer cell tumorgenicity by interacting with the production of tumor associated macrophages. At this stage, this hypothesis lacks sufficient empirical evidence. Our study is an investigation of the effects of let-7a on the function of human breast cancer cell lines that had undergone chemokine ligand 18 (CCL18) stimulation.MethodsTwo breast cancer cell lines MDA-MB-231 and MCF-7 were transfected with let-7a mimics with or without CCL18 simulation. The expression level of let-7a was evaluated with qRT-PCR. Our study examined cell proliferation, migration and cell cycles following let-7a treatment. The predicted target of let-7a was identified and confirmed in vitro by a dual luciferase reporter system. The associations between let-7a, CCL18 and target gene expression were evaluated using RT-PCR and the Western blotting method.ResultsThe downregulated expression level of let-7a was observed in both breast cancer cell lines. When compared to the control and CCL18 stimulation groups, cell proliferation and migration in MDA-MB-231 and MCF-7 cells were significantly inhibited by let-7a. Furthermore, the cell cycle was dramatically blocked at the G2/M phase. The luciferase reporter identified Lin28 as the direct binding target of let-7a in both breast cancer cell lines.ConclusionUpregulation of let-7a carries the potential to reverse CCL18 induced cell proliferation and migration alteration in breast cancer cells by regulating Lin28 expression. Our results provided evidence which suggests the use of let-7a as a therapeutic agent in the treatment of breast cancer.     

MicroRNA-199a-3p is downregulated in human osteosarcoma and regulates cell proliferation and migration

microRNAs (miRNA, miR) play an important role in cancer cell growth and migration; however, the potential roles of miRNAs in osteosarcoma remain largely uncharacterized. By applying a miRNA microarray platform and unsupervised hierarchical clustering analysis, we found that several miRNAs have altered expression levels in osteosarcoma cell lines and tumor tissues when compared with normal human osteoblasts. Three miRNAs, miR-199a-3p, miR-127-3p, and miR-376c, were significantly decreased in osteosarcoma cell lines, whereas miR-151-3p and miR-191 were increased in osteosarcoma cell lines in comparison with osteoblasts. Transfection of precursor miR-199a-3p into osteosarcoma cell lines significantly decreased cell growth and migration, thus indicating that the inhibition effect is associated with an increase in the G(1)-phase and a decrease of the S-phase cell population. In addition, we observed decreased mTOR and Stat3 expression in miR-199a-3p transfected cells. This study provides new insights for miRNAs in osteosarcoma and suggests that miR-199a-3p may play a functional role in osteosarcoma cell growth and proliferation. Restoring miR-199a-3p's function may provide therapeutic benefits in osteosarcoma.     

Systemic Delivery of Tumor Suppressor microRNA Mimics Using a Neutral Lipid Emulsion Inhibits Lung Tumors in Mice

MicroRNAs (miRNAs) are emerging as potential cancer therapeutics, but effective delivery mechanisms to tumor sites are a roadblock to utility. Here we show that systemically delivered, synthetic miRNA mimics in complex with a novel neutral lipid emulsion are preferentially targeted to lung tumors and show therapeutic benefit in mouse models of lung cancer. Therapeutic delivery was demonstrated using mimics of the tumor suppressors, microRNA-34a (miR-34a) and let-7, both of which are often down regulated or lost in lung cancer. Systemic treatment of a Kras-activated autochthonous mouse model of non-small cell lung cancer (NSCLC) led to a significant decrease in tumor burden. Specifically, mice treated with miR-34a displayed a 60% reduction in tumor area compared to mice treated with a miRNA control. Similar results were obtained with the let-7 mimic. These findings provide direct evidence that synthetic miRNA mimics can be systemically delivered to the mammalian lung and support the promise of miRNAs as a future targeted therapy for lung cancer.     

血清微小RNA作为早期乳癌诊断标志物的价值

目的探讨血清5种微小RNA（miRNA）在乳癌早期诊断中作为生物标记物的价值。方法根据生物信息学数据库miRWalk的预测,选定5种与乳癌相关的miRNA（包括miR-31、miR-107、miR-155、miR-200c及miR-205）。采用实时荧光定量PCR检测5种miRNA在42例健康女性、66例乳癌病人中的相对表达量,根据受试者工作特征曲线（ROC曲线）下面积分析诊断乳癌的特异度和灵敏度。结果血清中miR-31、miR-107和miR-200c联合检测诊断乳癌的灵敏度为78.6%,特异度为88.7%。结论血清中miR-31、miR-107和miR-200c的组合有可能成为乳癌早期诊断的新指标。     

Antitumor Activity of miR-1280 in Melanoma by Regulation of Src

MicroRNAs (miRNAs) play a key role in cancer progression by coordinately repressing target genes involved in cell proliferation, migration, and invasion. miRNAs regulate gene expression by repressing translation or directing sequence-specific degradation of complementary mRNA. Here, we report that expression of miR-1280 is significantly suppressed in human melanoma specimens when compared with nevi, and in human melanoma cell lines when compared with cultured normal human melanocytes. The proto-oncogene Src was identified as a target of miR-1280 action. Levels of Src expression were significantly higher in melanoma samples and cell lines than in nevi and normal melanocytes. miR-1280 overexpression significantly suppressed the luciferase activity of reporter plasmids containing the full-length 3′ untranslated region of Src. miR-1280-mediated suppression of Src led to substantial decreases in melanoma cell proliferation, cell cycle progression, invasion, as well as induced melanoma cell apoptosis. The effects of miR-1280 overexpression on melanoma cell proliferation and growth were reversed by Src overexpression. Intratumoral delivery of miR-1280 significantly suppressed melanoma cell growth in vivo. Our results demonstrate a novel role for miR-1280 as a tumor suppressor in melanoma, identify the Src signaling pathway as a target of miR-1280 action, and suggest a potential therapeutic role for miR-1280 in melanoma.     

A miRNA Signature of Prion Induced Neurodegeneration

MicroRNAs (miRNAs) are small, non-coding RNA molecules which are emerging as key regulators of numerous cellular processes. Compelling evidence links miRNAs to the control of neuronal development and differentiation, however, little is known about their role in neurodegeneration. We used microarrays and RT-PCR to profile miRNA expression changes in the brains of mice infected with mouse-adapted scrapie. We determined 15 miRNAs were de-regulated during the disease processes; miR-342-3p, miR-320, let-7b, miR-328, miR-128, miR-139-5p and miR-146a were over 2.5 fold up-regulated and miR-338-3p and miR-337-3p over 2.5 fold down-regulated. Only one of these miRNAs, miR-128, has previously been shown to be de-regulated in neurodegenerative disease. De-regulation of a unique subset of miRNAs suggests a conserved, disease-specific pattern of differentially expressed miRNAs is associated with prion–induced neurodegeneration. Computational analysis predicted numerous potential gene targets of these miRNAs, including 119 genes previously determined to be also de-regulated in mouse scrapie. We used a co-ordinated approach to integrate miRNA and mRNA profiling, bioinformatic predictions and biochemical validation to determine miRNA regulated processes and genes potentially involved in disease progression. In particular, a correlation between miRNA expression and putative gene targets involved in intracellular protein-degradation pathways and signaling pathways related to cell death, synapse function and neurogenesis was identified.     

miR-200–containing extracellular vesicles promote breast cancer cell metastasis

Metastasis is associated with poor prognosis in breast cancer patients. Not all cancer cells within a tumor are capable of metastasizing. The microRNA-200 (miR-200) family, which regulates the mesenchymal-to-epithelial transition, is enriched in the serum of patients with metastatic cancers. Ectopic expression of miR-200 can confer metastatic ability to poorly metastatic tumor cells in some settings. Here, we investigated whether metastatic capability could be transferred between metastatic and nonmetastatic cancer cells via extracellular vesicles. miR-200 was secreted in extracellular vesicles from metastatic murine and human breast cancer cell lines, and miR-200 levels were increased in sera of mice bearing metastatic tumors. In culture, murine and human metastatic breast cancer cell extracellular vesicles transferred miR-200 microRNAs to nonmetastatic cells, altering gene expression and promoting mesenchymal-to-epithelial transition. In murine cancer and human xenograft models, miR-200–expressing tumors and extracellular vesicles from these tumors promoted metastasis of otherwise weakly metastatic cells either nearby or at distant sites and conferred to these cells the ability to colonize distant tissues in a miR-200–dependent manner. Together, our results demonstrate that metastatic capability can be transferred by the uptake of extracellular vesicles.     

Targeted Expression of miR-34a Using the T-VISA System Suppresses Breast Cancer Cell Growth and Invasion

Recurrence and metastasis result in a poor prognosis for breast cancer patients. Recent studies have demonstrated that microRNAs (miRNAs) play vital roles in the development and metastasis of breast cancer. In this study, we investigated the therapeutic potential of miR-34a in breast cancer. We found that miR-34a is downregulated in breast cancer cell lines and tissues, compared with normal cell lines and the adjacent nontumor tissues, respectively. To explore the therapeutic potential of miR-34a, we designed a targeted miR-34a expression plasmid (T-VISA-miR-34a) using the T-VISA system, and evaluated its antitumor effects, efficacy, mechanism of action, and systemic toxicity. T-VISA-miR-34a induced robust, persistent expression of miR-34a, and dramatically suppressed breast cancer cell growth, migration, and invasion in vitro by downregulating the protein expression levels of the miR-34a target genes E2F3, CD44, and SIRT1. In an orthotopic mouse model of breast cancer, intravenous injection of T-VISA-miR-34a:liposomal complex nanoparticles significantly inhibited tumor growth, prolonged survival, and did not induce systemic toxicity. In conclusion, T-VISA-miR-34a lead to robust, specific overexpression of miR-34a in breast cancer cells and induced potent antitumor effects in vitro and in vivo. T-VISA-miR-34a may provide a potentially useful, specific, and safe-targeted therapeutic approach for breast cancer.     

mir-17-5p、mir-92a、let-7b表达水平与非小细胞肺癌顺铂耐药的关系

目的探讨mir-17-5p、mir-92a、let-7b表达水平与非小细胞肺癌顺铂耐药关系。 方法以人非小细胞肺癌细胞系A549及其耐药株A549/DDP为研究对象,采用RT-PCR法检测mir-17-5p、mir-92a及let-7b在细胞中的表达水平,采用cck8检测其细胞存活情况,采用细胞克隆平台方法,检测转染前后细胞的增殖情况,采用流式细胞仪检测转染前后细胞的凋亡情况。 结果（1） A549/DDP细胞mir-17-5p的表达水平是A549细胞的2.11±0.25倍（P＜0.05）;A549/DDP细胞mir-92a的表达水平是A549细胞的 7.40 ± 1.05 倍（P＜0.05）;而A549/DDP 细胞let-7b 的表达水平是A549 细胞的（26.54 ± 2.90）%（P＜0.05）;（2）A549 转染mir-17-5pmimic,mir-92a mimic 以及let-7b inhibitor 后对顺铂的敏感性下降（P＜0.05）;A549/ddp 转染mir-17-5p inhibitor, mir-92a inhibitor以及let-7b mimic后对顺铂的敏感性增加（P＜0.05）;（3）A549转染mir-17-5p mimic,mir-92a mimic以及let-7b inhibitor 后,细胞形成克隆集落数量数量多于对照组（P＜0.05）;而A549/ddp 转染mir-17-5p inhibitor,mir-92a inhibitor 以及 let-7b mimic 后,细胞形成克隆集落数量数量少于对照组（P＜0.05）;（4）A549 转染mir-17-5p mimic,mir-92a mimic 以及let-7b inhibitor后,细胞凋亡率明显低于对照组（P＜0.05）;而a549/ddp转染mir-17-5p inhibitor,mir-92a inhibitor以及let-7b mimic后, 细胞凋亡率明显高于对照组（P＜0.05）。结论Mir-17-5p、mir-92a表达水平升高,let-7b表达水平下降,可以促进肺癌细胞增殖, 抑制其凋亡以及使肺癌细胞对顺铂敏感性下降。      

Development of microRNA-145 for therapeutic application in breast cancer

MicroRNAs, small non-coding RNAs, are key regulators of tumorigenesis and cancer metastasis through inhibition of gene expression. Therefore, there is increasing interest in developing anti-cancer therapies using microRNAs. In this study, we determined the therapeutic potency of microRNA-145(miR-145) against breast cancer. We found a reverse-correlation between the expression of miR-145 and its target genes, such as fascin-1, c-myc, SMAD2/3 and IGF-1R in breast cancer cell lines and breast cancer patient tissues. Transfected miR-145 mimicking double-stranded oligonucleotides was directly reduced cell proliferation and motility via interaction with 3′UTR of target gene and also indirectly regulates Wnt signaling. An inhibitor of miR-145 nullified this decreasing effect of miR-145 on cell proliferation and motility. We prepared an adenoviral constructed miR-145(Ad-miR-145) and subjected it to breast cancer cells in vitro and orthotopic breast cancer mice in vivo. Ad-miR-145 suppressed cell growth and motility in both the in vitro and in vivo systems. Furthermore, a treatment combining Ad-miR-145 with 5-FU significantly showed anti-tumor effects, compared to treating alone. In conclusion, this study demonstrated that miR-145 suppresses tumor growth by inhibition of multiple tumor survival effectors, and more we suppose that miR-145 is potentially useful in the therapy of breast cancers.     

miR-601 is a prognostic marker and suppresses cell growth and invasion by targeting PTP4A1 in breast cancer

MicroRNAs (miRNA) play important roles in the initiation and progression of breast cancer. Here, we investigated the role of miR-601 in breast cancer and found that its expression was significantly down-regulated in breast cancer tissues compared with matched adjacent non-cancerous breast tissues. Moreover, we found that down-regulation of miR-601 was closely associated with distant metastasis and poor distant metastasis-free survival in breast cancer. In addition, miR-601 levels were inversely correlated with metastatic potential of human breast cancer cell lines. Further experiments showed that ectopic overexpression of miR-601 suppressed breast cancer cell proliferation, migration and invasion, whereas miR-601 knockdown promoted breast cancer cell proliferation, migration and invasion. Furthermore, protein tyrosine phosphatase type IVA 1 (PTP4A1) was identified as a direct target of miR-601. Overexpression of miR-601 repressed PTP4A1 mRNA and protein expression. Conversely, inhibition of miR-601 increased PTP4A1 mRNA and protein expression. Taken together, our data suggest that miR-601 inhibits growth and invasion of breast cancer cells by targeting PTP4A1 and that miR-601 is a potential biomarker for prognosis and therapeutic target in breast cancer.     

Reduced miR-31 and let-7 maintain the balance between differentiation and quiescence in lung cancer stem-like side population cells

Recent studies have indicated that side population (SP) cells, which are an enriched source of cancer stem cells (CSCs), drive and maintain many types of human malignancies. SP cells have distinguishing biological characteristics and are thought to contribute to metastasis, therapy resistance, and tumor recurrence. In the present study, the miRNA expression profiles of SP cells and non-SP cells were compared using miRNA array analysis. Both let-7 and miR-31 were significantly down-regulated in SP cells compared to non-SP cells. The results were confirmed by real-time PCR. Engineered repression of miR-31 caused marked repression of both lung cancer SP cell and non-SP cell growth in vitro. In contrast, engineered repression of let-7 caused marked promotion of both lung cancer SP and non-SP cells growth in vitro. Cell cycle studies further revealed that reduced miR-31 could inhibit SP cell proliferation by a cell cycle arrest in the G0/G1 phase, whereas reduced let-7 induced SP cell proliferation by accelerating G1/S phase transition. Notably, reduced miR-31 prevented SP cell differentiation, whereas reduced let-7 promoted SP cell differentiation under differentiation conditions. These findings indicate that reduced miR-31 and let-7 are involved in maintaining the balance between differentiation and quiescence in SP cells.     

Retracted Article: Exosomal miR-25-3p derived from hypoxia tumor mediates IL-6 secretion and stimulates cell viability and migration in breast cancer

Hypoxia is a major hallmark of solid tumors and is associated with malignant phenotypes. Exosomal miRNAs derived from hypoxia tumor cells are implicated in the modulation of cancer progression, whereas, the mechanisms underlying the association between hypoxia and exosomal miR-25-3p during breast cancer progression remain to be further clarified. The present study aimed to investigate the role of exosomal miR-25-3p in regulating breast cancer progression. Herein, we found that miR-25-3p expression was increased in hypoxia tumor-derived exosomes a HIF-1α-dependent manner. Hypoxia exosomes markedly stimulated the viability and migration of normoxia breast cancer cells, which was reversed by miR-25-3p depletion. Inhibition of exosomes miR-25-3p lowered hypoxic-induced the expression of IL-6 and NF-κB from THP-1 and RAW264.7 cells in a TLR7/8-dependent way. Treatment of macrophage supernatant (MS) initially incubated with hypoxic-responsed exosomes accelerated the viability and migration of breast cancer cells, and miR-25-3p depletion relieved the stimulatory effects of hypoxic on cell viability and migration. Moreover, miR-25-3p knockdown dramatically suppressed HIF-1α-induced tumor growth in vivo via inactivation of IL-6/STAT3 signaling pathway, reflected by the abated abundances of IL-6 and p-STAT3. These data suggested that absence of exosomal miR-25-3p rescued breast cancer aggressiveness through inhibiting cell viability and migration by regulation of IL-6 secretion from macrophages, providing a potential biomarker for breast cancer treatment.

Hypoxia is a major hallmark of solid tumors and is associated with malignant phenotypes.     

MicroRNA profiling in migraine without aura: Pilot study

Background and purpose. MicroRNAs (miRNAs) are short, non-coding RNAs whose deregulation has been shown in several human diseases, including pain states and diseases associated with increased cardiovascular (CV) risk. This study aimed at identifying differentially expressed circulating miRNAs in patients with ‘migraine without aura’ (MO), a pain condition whose link with CV risk remains debated.

Methods. Fifteen female MO patients and 13 matching healthy controls underwent a circulating microRNA expression profiling. MiR-22, miR-26a, miR-26b, miR-27b, miR-29b, let-7b, miR-181a, miR-221, miR-30b, and miR-30e were selected for validation by quantitative real-time polymerase chain reaction.

Results. In migraineurs versus controls, four miRNAs were differentially expressed: miR-27b was significantly up-regulated (q < 0.004), while miR-181a, let-7b, and miR-22 were significantly down-regulated (q ≤ 0.01). MiR-22 and let-7b down-regulation was also confirmed in circulating blood monocytes. A logistic regression model based on microRNA expression profile showed a high accuracy for identifying migraine (AUC of ROC curve: 0.956; P < 0.001).

Conclusion. A specific circulating miRNAs profile is associated with migraine without aura. Remarkably, the same miRNAs are known to be modulated in the setting of atherosclerosis and stroke in humans. This study represents a first step towards further characterization of MO diagnosis/pathophysiology, also in relation to its link with cardiovascular risk.     

MiR-595 targeting regulation of SOX7 expression promoted cell proliferation of human glioblastoma

Increasing evidence indicated that dysregulation of microRNAs (miRNAs) were involved with human disease including cancer. Recently, miR-595 was reported as a tumor promoter in malignant mesothelioma. However, the underlying mechanism of miR-595 in human glioblastoma (GBM) cells have not been well elucidated. Therefore, in this study, we investigated the biological functions and molecular mechanisms of miR-595 in human GBM. MiR-595 expression was significantly upregulated in GBM tissues and cells. We modified miR-595 levels in GBM cells and investigated their effects on the cell proliferation by MTT, colony formation and anchorage-independent growth assays. We found that miR-595 significantly increased GBM cell proliferation. Bioinformatic analysis predicted that miR-595 may target the 3′-UTR of SOX7and suppressed its translation, and further confirmed by luciferase assay. In sum, these observations together indicated that miR-595 played a critical role in carcinogenesis by suppression of SOX7, and may serve as a therapeutic target for the treatment of GBM.     

miR-92a/DUSP10/JNK signalling axis promotes human pancreatic cancer cells proliferation

Pancreatic cancer is one of the most common types of cancers in the whole world with a poor prognosis. Finding out how the cancer form and develop is the most important way to cure this cancer. miRNAs, 21–22 nucleotides regulatory small non-coding RNAs, have been found to be critical involved in the growth of pancreatic cancer. In this study, we found that miR-92a was up regulated in three kinds of human pancreatic cancer cell lines. There is a correlation between miR-92a and malignant degree of human pancreatic cancer cell lines. Then we found that miR-92a was essential for promoting cell proliferation in human pancreatic cancer. Inhibition of the function of miR-92a repressed the proliferation of pancreatic cancer cells. Further, we found that miR-92a enhanced the activation of JNK signalling pathway by directly targeting the JNK signalling inhibitor DUSP10. DUSP10 is responsible for miR-92a induced JNK signalling and cell proliferation. Altogether, our study showed a miR-92a/DUSP10/JNK signalling pathway that plays an important role in regulating the proliferation of pancreatic cancer cells.