Identification of differentially expressed microRNAs by microarray: a possible role for microRNAs gene in medulloblastomas / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>MicroRNAs (miRNAs) are small noncoding regulatory RNAs whose aberrant expression may be observed in many malignancies. However, few data are yet available on human primary medulloblastomas. This work aimed to identify that whether miRNAs would be aberrantly expressed in tumor tissues compared with non-tumorous cerebellum tissues from same patients, and to explore a possible role during carcinogenesis.</p><p><b>METHODS</b>A high throughput microRNA microarray was performed in human primary medulloblastoma specimens to investigate differentially expressed miRNAs, and some miRNAs were validated using real-time quantitative RT-PCR method. In addition, the predicted target genes for the most significantly down- or up-regulated miRNAs were analyzed by using a newly modified ensemble algorithm.</p><p><b>RESULTS</b>Nine miRNA species were differentially expressed in medulloblastoma specimens versus normal non-tumorous cerebellum tissues. Of these, 4 were over expressed and 5 were under expressed. The changes ranged from 0.02-fold to 6.61-fold. These findings were confirmed using real-time quantitative RT-PCR for most significant deregulated miRNAs (miR-17, miR-100, miR-106b, and miR-218) which are novel and have not been previously published. Interestingly, most of the predicted target genes for these miRNAs were involved in medulloblastoma carcinogenesis.</p><p><b>CONCLUSIONS</b>MiRNAs are differentially expressed between human medulloblastoma and non-tumorous cerebellum tissue. MiRNAs may play a role in the tumorigenesis of medulloblastoma and maybe serve as potential targets for novel therapeutic strategies in future.</p>

MiRE: a graphical R package for microRNA-related analysis / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To provide a set of useful analysis tools for the researchers to explore the microRNA data.</p><p><b>METHODS</b>The R language was used for generating the Graphical Users Interface and implementing most functions. Some Practical Extraction and Report Language (Perl) scripts were used for parsing source files.</p><p><b>RESULTS</b>We developed a graphical R package named miRE, which was designated for the analysis of microRNA functions, genomic organization, etc. This package provided effective and convenient tools for molecular biologists to deal with routine analyses in microRNA-related research. With its help, the users would be able to build a desktop-centered microRNA research environment quite easily and effectively. miRE is freely available at http://www. biosino.org/-kanghu/WorkPresentation/miRE/miRE.html. A detailed user manual and tutorials with example code and image are also available.</p><p><b>CONCLUSION</b>miRE is a tool providing an open-source, user-friendly, integrated interface for microRNA-related analysis. With its help, researchers can perform microRNA-related analysis more efficiently.</p>

MiR-9 regulates the expression of CBX7 in human glioma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To detect the expression of CBX7 in human glioma and investigate the potential regulatory effect of abnormally expressed microRNAs on CBX7 expression.</p><p><b>METHODS</b>Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot were applied to detect the expression pattern of CBX7 in 2 human normal brain tissues, 9 glioma tissues, and 3 glioma cell lines. Miranda algorithm and Ensemble Machine Learning algorithm were combined to predict miRNAs that target human CBX7. The expression of miR-9 in those tissues and cell lines were detected by real-time PCR. After miR-9 overexpression in 293ET and miR-9 knock-down in T98G, luciferase assay and Western blot were used to confirm the effect of miR-9 on CBX7 expression. MTT assay and flow cytometry were applied to detect the effect of miR-9 knock-down on T98G cells.</p><p><b>RESULTS</b>No obvious difference in the CBX7 mRNA level between normal and tumor tissues was observed, while the protein level of CBX7 was abrogated or markedly reduced in glioma tissues and cell lines. Several miRNAs including miR-9 may target CBX7 by bioinformatics prediction. MiR-9 was up-regulated in glioma tissues and cell lines. In 293ET cell, luciferase activity of CBX7-3'UTR reporter was decreased to 24% after miR-9 overexpression. After miR-9 knock-down in T98G cell, the luciferase activity was increased by 1.8 fold and there was no change of CBX7 mRNA, while the protein level of endogenous CBX7 was significantly increased. The number of survival T98G cells increased and cells in G1 phase decreased after miR-9 knock-down.</p><p><b>CONCLUSION</b>In human glioma, CBX7 is down-regulated by the inhibition of miR-9 at posttranscriptional level.</p>

Role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured rat neurons / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured neurons.</p><p><b>METHODS</b>Semi-quantitive reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression pattern of Necl1 in the neuronal differentiation cell model in vitro. Western blot was performed to detect the expression pattern of Necl1 in primary cultured rat neurons and in purified synaptosome. Immunofluoresence was used to detect the synapse formation in primary neurons and in 293 cells co-culture and to detect the density of synapses in primary neuron with ectopic expression of Necl1.</p><p><b>RESULTS</b>Necl1 expression increased after retinoic acid (RA) induction in SH-SY5Y and P19 cells. The increase of Necl1 expression was consistent with the days of primary neurons culture in vitro, and Necl1 partly localized in synaptosome. The overexpression of Necl1 in 293 cells induced the synapse formation between cocultured 293 cells and neurons. Ectopic expression of Necl1 in primary neurons increased the density of synapses.</p><p><b>CONCLUSION</b>Necl1 plays an important role in neuronal synapse formation.</p>

Effect of NECL1 on the proliferation of T98G glioma cell line / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the regulation role of tumor suppressor NECL1 on the proliferation of glioma cell line.</p><p><b>METHODS</b>We detected the expression level of NECL1 in human normal brain tissue and glioma cell lines using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. T98G cell line in which NECL1 was silent and whose transfection efficiency was relatively high as target cell was chosen, and the effect of NECL1 on the proliferation of T98G cell line in vitro was detected by using cell growth curve, flow cytometry, and Hoechst staining.</p><p><b>RESULTS</b>NECL1 was abrogated or markedly reduced in 6 glioma cell lines. When NECL1 was overexpressed in T98G cell line, the cell growth rate obviously decreased and the number of apoptotic cells remarkably increased when compared with the control group.</p><p><b>CONCLUSION</b>NECL1 may inhibit the proliferation of T98G cells by inducing its apoptosis.</p>

Expression pattern of polycomb gene Nspc1 at the early developmental stage in zebrafish / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the expression pattern of Polycomb gene Nspc1 at the early developmental stage in zebrafish.</p><p><b>METHODS</b>In situ hybridization probe for Nspc1 was designed according to the GenBank information. Collecting zebrafish embryos at different stages including one cell stage, two-cell stage, bud stage, and somites stage, we hybridized them with the prepared probe. Then the hybridization signals at different intervals were observed and photographed at the right time.</p><p><b>RESULTS</b>Nspc1 was expressed globally at the early stage. Its expression specificity began at the somites stage, mainly in the nervous system of the head.</p><p><b>CONCLUSION</b>Nspc1 may play essential roles in the early stage development of zebrafish, especially in the nervous system.</p>

Bioluminescent imaging monitoring of a anti-angiogenesis therapeutic gene vasostatin in tumor cell PC3 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To generate a sensitive tool for noninvasive monitoring of a therapeutic gene vasostatin.</p><p><b>METHODS</b>We fused the bioluminescent reporter gene firefly luciferase to the therapeutic transgene vasostatin and ensured that these two proteins would not interrupt each other and kept their own natural character.</p><p><b>RESULTS</b>We therefore examined clones of PC3 cells stably expressing fusion gene and positive controlfluc with bioluminescence. In vivo imaging of PC3-Fluc subcutaneous tumors showed that the mean tumor bioluminescence increased in animals over several weeks.</p><p><b>CONCLUSION</b>Noninvasive monitoring facilitates the detection of gene expression in vivo and in vitro.</p>