MicroRNAs 与肺动脉高压

肺动脉高压(pulmonary artery hypertension,PAH)是各种原因引起的肺动脉压力持续升高的临床综合征,最终可导致右心衰竭以及死亡。微小 RNA(microRNAs,miRNAs)是真核细胞中一大类参与基因转录后调控的非编码小分子 RNA。miRNAs 通过参与 BMP/Smad 通路、Src/STAT3/Pim1通路、缺氧诱导因子-1α与 P53等信号通路的调控,影响 PAH 的发生发展。PAH 时,肺组织中某些miRNAs 表达可出现明显下调(miR-451和 miR-124等)或上调(miR-23b、miR-130a 和 miR-191等),可能是 PAH 的早期诊断生物标记物,对 miRNAs 与 PAH 的关系的深入研究可能为 PAH 的临床诊疗提供新的思路与靶点。     

microRNA profiling in three main stages during porcine spermatogenesis

BackgroundSpermatogenesis is an intricate biological event wherein an undifferentiated spermatogonium develops into mature sperms. MicroRNAs are a type of single strand small non-coding RNA molecule and are implicated in the regulation of many crucial pathways during cell proliferation, apoptosis, and differentiation.MethodHere, we present a comprehensive comparison of miRNA expression profiling in three main stages during porcine spermatogenesis using high-throughput sequencing.ResultsWe built three small RNA libraries for the testis, the epididymis and the ejaculated sperm from a Landrace boar, and in total obtained 3821 precursor hairpins encoding for 4761 mature miRNAs, of which 23 are miRNA*. Notably, 940 precursor miRNAs produced both the 5’- and 3’- strands as sister pairs, indicating the distinctive expression patterns of germ cell miRNAs. Additionally, 418 out of 710 co-expressed miRNAs were identified as being differentially expressed between libraries (P < 0.001). Apart from the sexual specific X chromosome, many miRNAs were found to be located on chromosome 12, which may play potential roles in spermatogenesis according to the result of synteny analysis with human and mouse. The Gene Ontology and KEGG pathway analysis revealed that the target genes of co-expressed miRNAs were highly involved in the cell cycle process, metal ion binding, modification of plasma membrane, and the p53 signal pathway.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-014-0406-x) contains supplementary material, which is available to authorized users.     

miRNA profiling in vitreous humor,vitreal exosomes and serum from uveal melanoma patients: Pathological and diagnostic implications

Uveal melanoma (UM) represents approximately 5–6% of all melanoma diagnoses and up to 50% of patients succumb to their disease. Although several methods are available, accurate diagnosis is not always easily feasible because of potential accidents (e.g., intraocular hemorrhage). Based on the assumption that the profile of circulating miRNAs is often altered in human cancers, we verified whether UM patients showed different vitreous humor (VH) or serum miRNA profiles with respect to healthy controls. By using TaqMan Low Density Arrays, we analyzed 754 miRNAs from VH, vitreal exosomes, and serum of 6 UM patients and 6 healthy donors: our data demonstrated that the UM VH profile was unique and only partially overlapping with that from serum of the same patients. Whereas, 90% of miRNAs were shared between VH and vitreal exosomes, and their alterations in UM were statistically overlapped with those of VH and vitreal exosomes, suggesting that VH alterations could result from exosomal dysregulation. We report 32 miRNAs differentially expressed in UM patients in at least 2 different types of samples analyzed. We validated these data on an independent cohort of 12 UM patients. Most alterations were common to VH and vitreal exosomes (e.g., upregulation of miR-21,-34 a,-146a). Interestingly, miR-146a was upregulated in the serum of UM patients, as well as in serum exosomes. Upregulation of miR-21 and miR-146a was also detected in formalin-fixed, paraffin-embedded UM, suggesting that VH or serum alterations in UM could be the consequence of disregulation arising from tumoral cells. Our findings suggest the possibility to detect in VH and serum of UM patients “diagnostic” miRNAs released by the affected eye: based on this, miR-146a could be considered a potential circulating marker of UM.     

microRNAs with prognostic significance in pancreatic ductal adenocarcinoma: A meta-analysis

BackgroundReports have described the prognostic relevance of microRNAs (miRNAs) in patients treated for pancreatic ductal adenocarcinoma (PDAC). However, many of these include small numbers of patients. To increase statistical power and improve translation, we performed a systematic review and meta-analysis to determine a pooled conclusion. We examined the impact of miRNAs on overall survival (OS) and disease-free survival (DFS) in PDAC.MethodsEligible studies were identified and quality assessed using multiple search strategies (last search December 2014). Data were collected from studies correlating clinical outcomes with dysregulated tumoural or blood miRNAs. Studies were pooled, and combined hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate strength of the associations.ResultsTwenty studies involving 1525 patients treated for PDAC were included. After correcting for publication bias, OS was significantly shortened in patients with high tumoural miR-21 (adjusted HR = 2.48; 1.96–3.14). This result persisted when only studies adjusting for adjuvant chemotherapy were combined (adjusted HR = 2.72; 1.91–3.89). High miR-21 also predicted reduced DFS (adjusted HR = 3.08; 1.78–5.33). Similarly, we found significant adjusted HRs for poor OS for high miR-155, high miR-203, and low miR-34a; and unadjusted HRs for high miR-222 and high miR-10b. The small number of studies, limited number of miRNAs and paucity of multivariate analyses are the limitations of our study.ConclusionsThis is the first rigorous pooled analysis assessing miRNAs as prognostic biomarkers in PDAC. Tumoural miR-21 overexpression emerged as an important predictor of poor prognosis after PDAC resection independent of other clinicopathologic factors, including adjuvant chemotherapy use.     

Tumor suppressive microRNA-137 negatively regulates Musashi-1 and colorectal cancer progression

Stem cell marker, Musashi-1 (MSI1) is over-expressed in many cancer types; however the molecular mechanisms involved in MSI1 over-expression are not well understood. We investigated the microRNA (miRNA) regulation of MSI1 and the implications this regulation plays in colorectal cancer. MicroRNA miR-137 was identified as a MSI1-targeting microRNA by immunoblotting and luciferase reporter assays. MSI1 protein was found to be highly expressed in 79% of primary rectal tumors (n=146), while miR-137 expression was decreased in 84% of the rectal tumor tissues (n=68) compared to paired normal mucosal samples. In addition to reduced MSI1 protein, exogenous expression of miR-137 inhibited cell growth, colony formation, and tumorsphere growth of colon cancer cells. Finally, in vivo studies demonstrated that induction of miR-137 can decrease growth of human colon cancer xenografts. Our results demonstrate that miR-137 acts as a tumor-suppressive miRNA in colorectal cancers and negatively regulates oncogenic MSI1.     

MicroRNA dysregulation in uveal melanoma: a new player enters the game

Uveal melanoma is the second most common form of melanoma and a predominant intraocular malignant tumor in adults. The development of uveal melanoma is a multistep process involving genetic and epigenetic alteration of proto-oncogenes and tumor-suppressor genes. Recent discoveries have shed a new light on the involvement of a class of noncoding RNA known as microRNAs (miRNAs) in uveal melanoma. A lot of miRNAs show differential expressions in uveal melanoma tissues and cell lines. Genes coding for these miRNAs have been characterized as novel oncogene and tumor-suppressor genes based on findings that these miRNAs control malignant phenotypes of uveal melanoma cells. Several studies have confirmed that dysregulation of miRNAs promotes cell-cycle progression, confers resistance to apoptosis, and enhances invasiveness and metastasis. Moreover, several miRNAs have also been shown to correlate with uveal melanoma initiation and progression, and thus may be used as biomarkers for early diagnosis and prognosis. Elucidating the biological aspects of miRNA dysregulation may help us better understand the pathogenesis of uveal melanoma and promote the development of miRNA directed-therapeutics against this disease.     

miR-211 suppresses hepatocellular carcinoma by downregulating SATB2

Dysregulation of microRNAs (miRs) is involved in carcinogenesis. Deregulation of miR-211 has recently been observed in many tumors, but its function in hepatocellular carcinoma (HCC) is still unknown. Here we found that miR-211 was decreased in HCC cancer tissues compared with adjacent normal tissues. We also found that overexpression of miR-211 repressed proliferation and invasion in HepG2 and SMMC7721 cells. Luciferase reporter assays and western blot indicated that special AT-rich sequence-binding protein-2 (SATB2), is a direct target of miR-211. The expression of SATB2 was upregulated in HCC cancer tissues and cell lines and miR-211 levels inversely correlated with SATB2 levels in HCC. Importantly, SATB2 rescued the miR-211-mediated inhibition of cell invasion and proliferation. Finally, reintroduction of miR-211 repressed tumor formation of HCC in xenograft mice. This study provides insights into molecular mechanisms that miR-211 contributed to HCC.     

CRNDE affects the malignant biological characteristics of human glioma stem cells by negatively regulating miR-186

The long non-coding RNA Colorectal neoplasia differentially expressed (CRNDE) is a novel gene that activated early in colorectal neoplasia, but it is also up-regulated in many other solid tumors. Herein, the function and underlying mechanism of CRNDE in regulating glioma stem cells (GSCs) were investigated. We found that CRNDE expression was up-regulated while miR-186 expression was down-regulated in GSCs. Overexpression of CRNDE could promote the cellular proliferation, migration, invasion and inhibit the apoptosis in GSCs. Overexpression of miR-186 exerted functions of inhibiting the proliferation, migration and invasion of GSCs and promoting apoptosis. And CRNDE decreased the expression levels of XIAP and PAK7 by binding to miR-186 and negatively regulating it. In addition, miR-186 binded to XIAP and PAK7 3′UTR region, and decrease the expression of them, thus regulating the expression levels of downstream target proteins such as caspase 3, BAD, cyclin D1 and MARK2. The in vivo effect of CRNDE and miR-186 showed that the tumor formation rate was minimum in tumor-bearing nude mice with the knockdown of CRNDE and the overexpression of miR-186. In conclusion, CRNDE played an oncogenic role of GSCs through the negative regulation of miR-186. Both CRNDE and miR-186 could be regarded as potential targets in the glioma therapy.     

上调microRNA-150表达对肝癌SMMC7721细胞增殖和凋亡的影响

目的 探讨上调microRNA- 150 (miR- 150)表达对肝癌SMMC7721细胞增殖和凋亡的影响及其可能机制.方法 SMMC7721细胞分成miR-150感染组(加入pGIPZ-miR-150慢病毒表达载体)、阴性对照组(加入只含GFP的慢病毒载体)和空白对照组(不转染).采用荧光定量PCR检测miR-150的表达情况,Western blotting检测靶基因c-Myb蛋白的表达,CCK-8法检测细胞增殖能力,流式细胞仪检测细胞凋亡情况.结果 荧光定量PCR结果显示,转染miR-150pGIPZ后,SMMC7721细胞miR-150表达量(2.48±0.15)较阴性对照组(0.81±0.09)增加了2倍(p＜0.01).CCK-8法检测结果显示,与阴性对照组和空白对照组比较,miR-150组的细胞增殖率显著降低(P＜0.05).Western blotting检测结果表明,miR-150组细胞c-Myb蛋白表达(0.31±0.07)与空白对照组(0.80±0.09)及阴性对照组(0.81±0.08)相比明显减少(P＜0.0l).流式细胞仪检测结果显示,miR-150组细胞凋亡率(19.36％±1.78％)与阴性对照组(5.12％±0.54％)及空白对照组(4.68％±0.35％)相比明显增加(P＜0.01).结论 上调miR-150表达可通过降低靶基因c-Myb的表达,抑制细胞增殖,诱导细胞凋亡,miR-150可能成为肝癌靶向治疗新的靶基因.     

心房颤动患者循环microRNAs表达谱的初步研究

目的 利用microRNA(miRNA)芯片研究持续性和阵发性心房颤动(房颤)患者循环miRNAs表达谱的改变,为进一步探讨miRNA对房颤的调控机制提供依据.方法 解放军总医院心内科2010年11月-2011年2月持续性房颤患者、阵发性房颤患者和健康对照者各5例,取其全血标本,提取血清总RNA,采用microRNA芯片进行杂交,得到miRNA表达谱,通过Volcano Plot方法寻找差异表达的miRNAs,并采用MEV软件进行聚类分析.结果 和健康对照者相比,阵发性和持续性房颤患者血清中表达都有明显差异的miRNA共有13个,其中表达上调的有8个:miR-3169,miR-3612,miR-634,miR-376a,miR-517b,miR-377*,miR-590-3p,miR-664;表达下调的有5个:miR-1,kshv-miR-K12-5,miR-378c,miR-204,miR-27a.阵发性房颤和持续性房颤患者间miRNA的表达谱也有显著差异.结论 持续性和阵发性房颤患者循环miRNAs表达谱有显著改变,提示循环miRNAs可用于房颤发生和发展过程中调控机制的研究.