Considering the low accuracy of prediction in the positive samples and poor overall classification effects caused by unbalanced sample data of MicroRNA (miRNA) target, we proposes a support vector machine (SVM)-integration of under-sampling and weight (IUSM) algorithm in this paper, an under-sampling based on the ensemble learning algorithm. The algorithm adopts SVM as learning algorithm and AdaBoost as integration framework, and embeds clustering-based under-sampling into the iterative process, aiming at reducing the degree of unbalanced distribution of positive and negative samples. Meanwhile, in the process of adaptive weight adjustment of the samples, the SVM-IUSM algorithm eliminates the abnormal ones in negative samples with robust sample weights smoothing mechanism so as to avoid over-learning. Finally, the prediction of miRNA target integrated classifier is achieved with the combination of multiple weak classifiers through the voting mechanism. The experiment revealed that the SVM-IUSW, compared with other algorithms on unbalanced dataset collection, could not only improve the accuracy of positive targets and the overall effect of classification, but also enhance the generalization ability of miRNA target classifier.
ObjectiveTo systematically evaluate the clinical value of miRNA-1 in the diagnosis of acute myocardial infarction (AMI) patients.MethodsWe searched PubMed, EMbase, Cochrane Library, CNKI, Wangfang, VIP, etc databases to identify literature about miRNA-1 in the diagnosis of AMI. Quality of the included literature was assessed by (quality assessment for diagnostic accuracy studies-2, QUADAS-2). The indices of pooled sensitivity (Sen), specificity (Spe), positivity likelihood ratio (PLR), negative likelihood ratio (NLR), diagnosis odds ratio (DOR), and the area under the summary receiver operating characteristic (SROC) curve were pooled using MetaDisc 1.4 software.ResultsA total of 12 articles were included. According to the different populations of miRNA-1 to be tested, subgroup analysis of healthy people (7 articles) and non-AMI disease groups (5 articles) was conducted. The results showed that AMI compared with healthy people, the pooled Sen was 0.78 with 95%CI 0.73 to 0.82, Spe was 0.88 with 95%CI 0.83 to 0.91 of miRNA-1 in the diagnosis of AMI. AUC of SROC curve was 0.911 2. Comparison of AMI and non-AMI patients, the pooled Sen was 0.59 with 95%CI 0.54 to 0.64, Spe was 0.74 with 95%CI 0.68 to 0.79 of miRNA-1 in the diagnosis of AMI. AUC of SROC curve was 0.743 2.ConclusionMiRNA-1 has a certain value in the diagnosis of AMI. It has an advantage in identifying AMI and patients with other systemic diseases, and can be combined with other biomarkers to diagnose AMI.
ObjectiveTo investigate the changes of lung function after exposure to fine particulate matter (PM2.5) for 60 days and the expression of miR-146 in mice.MethodsThirty SPF BALB/c mice were treated with noninvasive tracheal instillation of fine particulate matter suspension at different doses (2.5 mg/kg, 5.0 mg/kg, 10.0 mg/kg) for 2 months (two times one week), the blank group and normal saline group were set as control groups. The mice were examined and killed on the next day after the last instillation. Histopathological changes of the lungs, pro-infammatory factors levels in the lung tissues, pulmonary functions and the relative expression of miR-146a and miR-146b in the lung tissues were detected.ResultsPeak inspiratory flow (PIF) and peak expiratory flow (PEF) were decreased significantly after PM2.5 exposure, however, lung resistance increased and maximal voluntary ventilation reduced from the general tendency without significant difference. Hematoxylin-eosin stain showed lymphocyte infiltration and macrophage infiltration by phagocytic particles, alveolar spacer widening, inflammatory response increased with the increase of PM2.5 exposure dosage. Pro-infammatory factors as interleukin-6 in the bronchoalveolar lavage fluid, interferon-γ and tumor necrosis factor-α in the lung homogenate were increased significantly by enzyme linked immunosorbent assay. The relative expressions of miR-146a and miR-146b were up-regulated remarkablely in treatment groups compared to the control group by real-time fluorescence quantitative polymerase chain reaction, which had negative relationships with PIF and PEF.ConclusionsThe lung function of mice decreases significantly after exposure to fine particulate matter, and the expression of miR-146 is up-regulated.
Vascular endothelial cell(VEC) is a kind of simple squamous epithelium lined on the inner surface of blood vessels. VEC is an important barrier between the blood and tissue and it also plays a key role in regulating inflammation, thrombosis, endothelial cells mediated vasodilatation and endothelial regeneration. These processes should be controlled by a variety of complex mechanism which requires us to find out. With results of the researches in vascular endothelial cell function, the important roles that microRNA in vascular endothelial cell function draws more and more researchers' attention. MicroRNAs control gene expression in post-transcriptional level and affect the function of endothelial cells. This review focuses on the research progress on regulatory mechanism of microRNA to endothelial cell inflammation, thrombosis, vasodilation and endothelium regeneration.
Objective
To review the regulation of microRNA-17-92 cluster on bone development, remodeling, and metabolism.
Methods
The related literature was reviewed. The clinical genetic phenotype, animal experiment, and cell research were illustrated so as to explore the possible regulatory mechanisms.
Results
MicroRNA-17-92 cluster is involved in physiological normal organs development, pathological neoplasm occurrence, and development. Recently, studies have shown that microRNA-17-92 cluster constitutes an intricate molecular signaling network with its upstream transcription factors and downstream targeting proteins, which controls bone development, remodeling, and metabolism exquisitely.
Conclusion
Present fundamental researches have certain understanding of the regulatory mechanisms of microRNA-17-92 cluster on bone development, remodeling, and metabolism. However, the exact mechanisms under these processes remain unknown.
ObjectiveTo investigate the impact and mechanism of over-expression microRNA-92a (miR-92a) in clinicopathologic feature and prognosis of patients with colorectal cancer (CRC).
MethodsThe expression levels of miR-92a and phosphatase and tensin homologue (PTEN) gene in 108 cases of colorectal cancer tissues were detected by using real-time fluorescent quantitative PCR (RT-PCR), and they were categorized as low or high in relation to the median value. Then the association between different levels of miR-92a gene expression and clinicopathologic feature and prognosis of CRC patients were evaluated. Moreover, the relationship between the expressions of miR-92a and PTEN gene were analyzed.
ResultsHigh expression of miR-92a not only associated with lymph node metastasis (χ2=8.045, P=0.007), distant metastasis (χ2=5.708, P=0.030), and TNM staging (χ2=6.366, P=0.019) of CRC patients, but also related to the down-regulated of PTEN gene expression (χ2=21.333, P < 0.001). However, up-regulated miR-92a expression was negatively correlated with age, gender, tumor size, tumor location, depth of invasion and tumor differentiation. In addition, Kaplan-Meier survival curves showed that over-expression of miR-92a and low-expression of PTEN gene could potentially predict poor overall survival of CRC patients.
ConclusionThe high expression of miR-92a can lead to a poor clinical prognosis of CRC patients through decreasing the expression level of PTEN gene.
Objective To summarize the research progress of microRNA （miRNA） as a tumor marker in peripheral blood. Methods The domestic and international published literatures about circulating miRNA as a tumor marker in recent years were reviewed. Results The miRNA expression has universality，stability and specificity，and it is related to the occurrence and development of viarous diseases. Conclusion Circulating miRNA shows a broad application prospect in clinical diagnosis， treatment， and prognosis of tumor and other diseases.
Objective To summarize the domestic and abroad articles related to the research on the relation between microRNA （miRNA） and pancreatic cancer，and explore the important effects of miRNA expression patterns in diagnosis of pancreatic cancer. Methods “microRNA and pancreatic cancer” were searched as key words by PubMed and CNKI series full-text database retrieval systems from 2000 to 2012. Totally 60 English papers and 15 Chinese papers were obtained. Choice criteria：the basic research of miRNA and pancreatic cancer，the clinical research of miRNA and pancreatic cancer， and the prospect of miRNA in pancreatic cancer diagnosis and treatment. According to the choice criteria，31 papers were finally analyzed. Results The miRNA expression spectrum and specific miRNA expression such as miR-21，miR-34，miR-217，miR-196a，miR-10a，miR-155，miR-221，miR-222，miR-181a，miR-181b，miR-181d， and the family members of miR-200 and let-7 might be used as tumor markers to differentiate pancreatic cancer from normal pancreas，chronic pancreatitis or pancreatic endocrine tumors，and might be used as prognostic factor to predict the outcome. Conclusions miRNA expression spectrum are not only related to diagnosis of pancreatic cancer， but also have provided a new research direction and method for gene therapy of pancreatic cancer．
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR).
MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot.
ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05).
ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.
At present, there are relatively many clinical gene studies. microRNA -215 (miR-215) is a miRNA induced by p53. It exists in animals and humans. miR-215 can exist not only in tumor tissues, but also in blood, urine and feces. miR-215 is abnormally expressed in a variety of tumors and plays a role in promoting and inhibiting cancer. Therefore, miR-215 may provide a new research direction for tumor diagnosis, treatment and prognosis. This paper reviews the expression of miR-215 as a oncogene and tumor suppressor gene in tumors and in non tumors.
