Cardiomegaly ; genetics ; Gene Expression Regulation ; Humans ; MicroRNAs ; biosynthesis

Stroke is one of the leading causes of death and physical disability worldwide. The consequences of stroke injuries are profound and persistent, causing in considerable burden to both the individual patient and society. Current treatments for ischemic stroke injuries have proved inadequate, partly owing to an incomplete understanding of the cellular and molecular changes that occur following ischemic stroke. MicroRNAs (miRNA) are endogenously expressed RNA molecules that function to inhibit mRNA translation and have key roles in the pathophysiological processes contributing to ischemic stroke injuries. Potential therapeutic areas to compensate these pathogenic processes include promoting angiogenesis, neurogenesis and neuroprotection. Several miRNAs, and their target genes, are recognized to be involved in these recoveries and repair mechanisms. The capacity of miRNAs to simultaneously regulate several target genes underlies their unique importance in ischemic stroke therapeutics. In this Review, we focus on the role of miRNAs as potential diagnostic and prognostic biomarkers, as well as promising therapeutic agents in cerebral ischemic stroke.
Biomarkers ; Cause of Death ; Humans ; Ischemia ; MicroRNAs* ; Neurogenesis ; Neuroprotection ; Protein Biosynthesis ; RNA ; Stroke*

OBJECTIVETo investigate the effect of smoking on the microRNAs (miRNAs) expression in pneumoconiosis patients.

METHODSReal-time qPCR was used to measure the expression levels of miR-21, miR-200c, miR-16, miR-204, miR-206, miR-155, let-7g, miR-30b, and miR-192 in 36 non-smoking patients with pneumoconiosis and 38 smoking patients with pneumoconiosis, and the differences in expression levels between the two groups were evaluated by two-independent samples t-test.

RESULTSThe expression of miR-192 in serum showed a significant difference between non-smoking and smoking pneumoconiosis patients (P < 0.05), and it decreased gradually in smoking patients with stage I and II pneumoconiosis. In the serum of all pneumoconiosis patients, the expression level of miR-16 was the highest, while the expression level of miR-204 was the lowest.

CONCLUSIONPneumoconiosis patients have differential expression of miRNAs in serum, and smoking has an effect on the miRNAs expression in pneumoconiosis patients.

Humans ; MicroRNAs ; biosynthesis ; Pneumoconiosis ; metabolism ; physiopathology ; Polymerase Chain Reaction ; Smoking ; adverse effects

AIMTo construct the RNAi eukaryotic vector of inhibitory member of the prohibitin (PHB-1) gene and observe the interfering effect in HEK293 cell line after the vector transfection.

METHODSThe specific Mi RNA sequence was designed according to the PHB-1 sequence in GenBank, complementary single-strand DNA oligonucleotides were designed and synthesized, and annealed the single-stranded oligonucleotides to generate a double strands oligonucleotides , cloned the oligonucleotides into pcDNATM6.2-GW/EmGFP-MiR-PHB to obtain an entry clone and then sequence analysis was performed. The recombinant plasmid was transfected into HEK293 cell by liposome. PHB-1 expression was detected by Western blotting.

RESULTSThe DNA sequence of interest clone to the vector was constructed to generate an entry clone and an expression clone successfully, which were proved by sequence determination. Western blotting analysis demonstrated that PHB-1 MiR RNA expression construction could suppress the expression of PHB-1.

CONCLUSIONA RNAi eukaryotic vector containing prohibitin gene was successfully constructed.

Genetic Vectors ; genetics ; HEK293 Cells ; Humans ; MicroRNAs ; biosynthesis ; genetics ; RNA Interference ; RNA, Small Interfering ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Repressor Proteins ; biosynthesis ; genetics ; Transfection

The aim of the present study is to construct the recombinant eukaryotic expression and short hairpin RNA (shRNA) expression vectors of microRNA-21 and phosphatase and tensin homolog deleted on chromosome ten (PTEN). According to the gene sequence of microRNA-21 and PTEN, we designed and synthesized two pairs of single-stranded siRNA oligonucleotides and PCR primers. After annealing, the double-stranded DNA oligonucleotides were cloned into vector Psilencer4. 1-CMV. In addition, the gene sequences encoding pre-miR-21 and PTEN were amplified from colorectal cancer cell HCT-116 by RT-PCR. Then the PCR products were digested with restrictive endonuclease enzyme and cloned into vector pEGFP-N1. The constructed recombinant vectors were identified by restrictive digestion and DNA sequence analysis. The positive clone was confirmed by double enzyme digestion, and the enzyme fragments were consistent with the vector and purpose gene sequence. DNA sequencing confirmed that the purpose oligonucleotide fragments were correctly inserted in to the eukaryotic expression plasmids. It could be concluded that the microRNA-21 and PTEN eukaryotic expression and shRNA expression vectors have been successfully constructed, providing a foundation for further study on the effect of miR-21 on human colorectal cancer.
Base Sequence ; Cell Line, Tumor ; Cloning, Molecular ; Colonic Neoplasms ; genetics ; pathology ; Genetic Vectors ; genetics ; Humans ; MicroRNAs ; biosynthesis ; genetics ; Molecular Sequence Data ; PTEN Phosphohydrolase ; biosynthesis ; genetics ; RNA, Small Interfering ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

Over-expression of Fas ligand (FasL) on tumor cell surface can induce the apoptosis of specific activated tumor infiltrating lymphocytes (TILs) via the Fas/FasL pathway, leading to the formation of a site of immune privilege surrounding the tumor mass for escaping immune surveillance and promoting tumor proliferation, invasion and metastasis. The blocking effect of miR-21 on FasL-mediated apoptosis in breast cancers was investigated in this study. The expression levels of miR-21 and FasL in human breast carcinoma cell lines were detected by using RT-PCR and Western blotting. FasL as a target gene of miR-21 was identified by Luciferase assay. The apoptosis of Jurkat T lymphocytes induced by MCF-7 cells was determined by flow cytometry. It was found that in four human breast cancer cell lines, FasL expression level in MCF-7 cells was the highest, while miR-21 was down-regulated the most notably. After miR-21 expression in MCF-7 cells was up-regulated, FasL was identified as a target gene of miR-21. When the effector/target (E/T) ratio of MCF-7 cells and Jurkat cells was 10:1, 5:1 and 1:1, the inhibitory rate of apoptosis of Jurkat T lymphocytes induced by MCF-7 cells was 95.81%, 93.16% and 91.94%, respectively. It is suggested that in breast cancers miR-21 expression is negatively associated with FasL expression, and FasL is a target gene of miR-21. miR-21 targeting and regulating FasL-mediated apoptosis will bring us the possibility of a new tumor immunotherapy via breaking tumor immune privilege.
Apoptosis ; genetics ; Breast Neoplasms ; genetics ; Fas Ligand Protein ; biosynthesis ; metabolism ; Female ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; Humans ; MCF-7 Cells ; MicroRNAs ; biosynthesis ; genetics ; Signal Transduction

Objective To investigate effect of let-7a gene over-expression on apoptosis of gastric cancer cell lines SGC-7901.Methods The stable let-7a gene over-expressing SGC-7901 cells, SGC-7901/let-7a cells, were established using shRNA lentiviral vector methods. Real-time RT-PCR analysis was used to evaluate the expression level of let-7a mRNA. Cells apoptosis was assessed by flow cytometry.Results RT-PCR analysis revealed let-7a expression in SGC-7901/let-7a cells was significantly increased. Cellular apoptosis assay showed that over-expression of let-7a could increase apoptosis of SGC-7901 cells (P=0.002).Conclusion Up-regulating let-7a expression promoted apoptosis in SGC-7901 cells.
Apoptosis ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; biosynthesis ; genetics ; RNA, Neoplasm ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Up-Regulation

Plant and animal genomes contain an abundance of small genes that produce RNAs of about 22 nucleotides in length, which was dubbed as microRNA (miRNA). These newly found endogenous RNAs may participate in a wide range of genetic regulatory pathways and play an important role in the organism development. This paper reviewed the recent studies and progress on the characteristics, functions and mechanisms of the microRNAs, as well as the advances of research on lymphoid malignancies.
Animals ; Humans ; Leukemia, Lymphoid ; genetics ; Lymphoma ; genetics ; Lymphoproliferative Disorders ; genetics ; MicroRNAs ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics

We developed a method for monitoring of miRNA activity in live cells by a secreted luciferase gene based plasmid sensor named as Gsensor. Firstly, we constructed pAAV2neo-Gluc-MCS-polyA as "empty Gsensor", which contained multiple cloning sites (MCS) for miRNA target inserted. To detect miR142-3p activity, miR142-3p Gsensor and miR142-3p Gsensor-3 were constructed by inserting one or three complementary miR142-3p targets into pAAV2neo-Gluc-MCS-ployA. Subsequently, miR142-3p Gsensor and miR142-3p Gsensor-3 were respectively transfected into U937 cells and Gluc activity was assayed in the supernatant 48 h post transfection. Results showed that both of them effectively indicated miR142-3p activity of inhibiting Gluc expression compared with empty Gsensor. Simultaneously, miR142-3p Gsensor also demonstrated the inhibition of miR142-3p activity by Anti-miR142 when they were cotransfected into U937 cells. This implied one copy of miRNA target in Gsensor was sensitive enough for investigation of miRNA activity. We further analyzed factors affecting Gsensor function including time and dose, and found that miR142-3p activity sensed by miR142-3p Gsensor rose within 48 h post transfection and approached stable thereafter. Transfected dose varying among 0.001-0.05 pg/cell had little effect on its function. Using miR142-3p Gsensor, we further detected miR142-3p activity in HEK293, U937, K562, SP2/0 and P815 cells. Results suggested that miR142-3p activity was high in U937, K562, SP2/0 and P815 cells and almost negative in HEK293. miR142-3p activity was positively correlated with its relative copies in HEK293, U937 and K562 detected by QRT-PCR. In conclusion, Gsensor proved to be an effective tool for monitoring of miRNA activity in live cells, and provide a new method for monitoring miRNA activity in vitro.
Genes, Reporter ; genetics ; Genetic Vectors ; HEK293 Cells ; Humans ; K562 Cells ; Luciferases ; biosynthesis ; genetics ; MicroRNAs ; metabolism ; Transfection ; U937 Cells

The let-7 miRNA was one of the first miRNAs discovered in the nematode, Caenorhabditis elegans, and its biological functions show a high level of evolutionary conservation from the nematode to the human. Unlike in C. elegans, higher animals have multiple isoforms of let-7 miRNAs; these isoforms share a consensus sequence called the 'seed sequence' and these isoforms are categorized into let-7 miRNA family. The expression of let-7 family is required for developmental timing and tumor suppressor function, but must be suppressed for the self-renewal of stem cells. Therefore, let-7 miRNA biogenesis must be carefully controlled. To generate a let-7 miRNA, a primary transcript is produced by RNA polymerase II and then subsequently processed by Drosha/DGCR8, TUTase, and Dicer. Because dysregulation of let-7 processing is deleterious, biogenesis of let-7 is tightly regulated by cellular factors, such as the RNA binding proteins, LIN28A/B and DIS3L2. In this review, we discuss the biological functions and biogenesis of let-7 miRNAs, focusing on the molecular mechanisms of regulation of let-7 biogenesis in vertebrates, such as the mouse and the human.
Animals ; Base Sequence ; Gene Expression Regulation ; Humans ; MicroRNAs ; biosynthesis ; chemistry ; genetics ; metabolism ; RNA Processing, Post-Transcriptional ; RNA Stability ; Transcription, Genetic