RNA-binding Protein UNR Promotes Glioma Cell Migration and Regulates the Expression of Ribosomal Protein L9.

Objective To investigate the role of RNA binding protein─upstream-of-N-Ras (UNR) in the development of glioma and its molecular mechanism.Methods First, bioinformatics analysis of CGGA database was performed to detect UNR expression level and prognosis of patients with glioma. Western blot and real-time PCR were used to detect UNR expression level in glioma cell lines and tissues. Next, UNR siRNAs were transfected in glioma cells, and MTS assay and scratch wound-healing assay were used to detect changes in cell proliferation and migration. Then, the candidate UNR target mRNAs were identified by analyzing the sequencing data of UNR iCLIP-seq, RNA sequencing and ribosome profiling databases of human melanoma. RNA immunoprecipitation and biotin pull-down assays were used to identify the UNR target mRNAs in glioma cells. Finally, western blot was used to detect the effect of UNR knockdown on ribosomal protein L9 (RPL9) and RPL9 protein expression level in glioma cell lines. RPL9 siRNA was transfected in A172 and T98G and the expression of vimentin in the cells was detected with western blot.Results Bioinformatics analysis showed that UNR mRNA expression level was significantly higher in high-grade glioma [Grade 2 (n=126), Grade 3 (n=51), Grade 4 (n=128), P<0.001]. UNR high expression levels were associated with poor prognosis (P=0.0177). UNR had high expression level in glioma cell lines and patient samples compared with normal cell lines and normal brain samples (P<0.01). Knockdown of UNR inhibited glioma cells migration (P<0.05), but did not inhibit glioma cells growth in three glioma cell lines. UNR binded the 3' untranslated region (UTR) of PTEN and RPL9 mRNAs. RPL9 protein was significantly highly expressed in most glioma cell lines (n=9) and knockdown of UNR resulted in a downregulation of RPL9 protein expression. Epithelial-mesenchymal transition (EMT)-related marker─vimentin was positively regulated by RPL9.Conclusions UNR could bind to the 3'UTR of PTEN and RPL9 in glioma cell lines, therefore promoting glioma cell migration and regulating the expression of RPL9. Here, we establish a link between UNR and RPL9 protein, which will provide new ideas for the further study of glioma.

DIXDC1 promotes retinoic acid-induced neuronal differentiation and inhibits gliogenesis in P19 cells.

Human DIXDC1 is a member of Dishevelled-Axin (DIX) domain containing gene family which plays important roles in Wnt signaling and neural development. In this report, we first confirmed that expression of Ccd1, a mouse homologous gene of DIXDC1, was up-regulated in embryonic developing nervous system. Further studies showed that Ccd1 was expressed specifically in neurons and colocalized with early neuronal marker Tuj1. During the aggregation induced by RA and neuronal differentiation of embryonic carcinoma P19 cells, expressions of Ccd1 as well as Wnt-1 and N-cadherin were dramatically increased. Stable overexpression of DIXDC1 in P19 cells promoted the neuronal differentiation. P19 cells overexpressing DIXDC1 but not the control P19 cells could differentiate into Tuj1 positive cells with RA induction for only 2 days. Meanwhile, we also found that overexpression of DIXDC1 facilitated the expression of Wnt1 and bHLHs during aggregation and differentiation, respectively, while inhibited gliogenesis by down-regulating the expression of GFAP in P19 cells. Thus, our finding suggested that DIXDC1 might play an important role during neurogenesis, overexpression of DIXDC1 in embryonic carcinoma P19 cells promoted neuronal differentiation, and inhibited gliogenesis induced by retinoic acid.

MiRE: a graphical R package for microRNA-related analysis.

OBJECTIVE: To provide a set of useful analysis tools for the researchers to explore the microRNA data. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Effect of NECL1 on the proliferation of T98G glioma cell line].

OBJECTIVE: To study the regulation role of tumor suppressor NECL1 on the proliferation of glioma cell line. METHODS: 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. RESULTS: 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. CONCLUSION: NECL1 may inhibit the proliferation of T98G cells by inducing its apoptosis.

[Expression pattern of polycomb gene Nspc1 at the early developmental stage in zebrafish].

OBJECTIVE: To study the expression pattern of Polycomb gene Nspc1 at the early developmental stage in zebrafish. METHODS: 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. RESULTS: Nspc1 was expressed globally at the early stage. Its expression specificity began at the somites stage, mainly in the nervous system of the head. CONCLUSION: Nspc1 may play essential roles in the early stage development of zebrafish, especially in the nervous system.

[MiR-9 regulates the expression of CBX7 in human glioma].

OBJECTIVE: To detect the expression of CBX7 in human glioma and investigate the potential regulatory effect of abnormally expressed microRNAs on CBX7 expression. METHODS: 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. RESULTS: 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. CONCLUSION: In human glioma, CBX7 is down-regulated by the inhibition of miR-9 at posttranscriptional level.

[Role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured rat neurons].

OBJECTIVE: To study the role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured neurons. METHODS: 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. RESULTS: 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. CONCLUSION: Necl1 plays an important role in neuronal synapse formation.

Mutation of the cellular adhesion molecule NECL2 is associated with neuromyelitis optica spectrum disorder.

AIMS: To investigate the association of the Nectin/Necl family genes with the risk of developing NMOSD. METHODS: Whole-exome sequencing was performed on two familial NMOSD cases and two unaffected family members. Additionally, 106 patients with sporadic NMOSD and 212 healthy controls (HCs) underwent screening for mutant Necl2. Finally, the molecular weight and cellular localization of mutant NECL2 was examined in transfected HeLa cells. RESULTS: We identified a novel deletion mutation in Necl2 (c.1052_1060delCCACCACCA; p. Thr351_Thr353del), which was associated with disease manifestation in the NMOSD familial cases. The frequency at which the mutation occurred in patients with sporadic NMOSD was significantly higher than for HCs (5.7% and 0, respectively; p<0.01). The mutation was located in the extracellular domain close to the transmembrane region, at a point in the protein sequence characterized by threonine enrichment. The mutant NECL2 had a lower molecular weight and exhibited defective trafficking to the cell surface. CONCLUSIONS: Our results suggest that the Necl2 mutation identified herein may be associated with the risk of developing NMOSD. Furthermore, mutated NECL2 may play a role in the pathogenesis of the disease, potentially through its roles in axonal regeneration and/or via neuron-glia interactions that are relevant to myelination.

The liver-enriched transcription factor CREB-H is a growth suppressor protein underexpressed in hepatocellular carcinoma.

We have previously characterized transcription factor LZIP to be a growth suppressor targeted by hepatitis C virus oncoprotein. In search of proteins closely related to LZIP, we have identified a liver-enriched transcription factor CREB-H. LZIP and CREB-H represent a new subfamily of bZIP factors. CREB-H activates transcription by binding to cAMP responsive element, box B, and ATF6-binding element. Interestingly, CREB-H has a putative transmembrane (TM) domain and it localizes ambiently to the endoplasmic reticulum. Proteolytic cleavage that removes the TM domain leads to nuclear translocation and activation of CREB-H. CREB-H activates the promoter of hepatic gluconeogenic enzyme phosphoenolpyruvate carboxykinase. This activation can be further stimulated by cAMP and protein kinase A. CREB-H transcript is exclusively abundant in adult liver. In contrast, the expression of CREB-H mRNA is aberrantly reduced in hepatoma tissues and cells. The enforced expression of CREB-H suppresses the proliferation of cultured hepatoma cells. Taken together, our findings suggest that the liver-enriched bZIP transcription factor CREB-H is a growth suppressor that plays a role in hepatic physiology and pathology.

[Bioluminescent imaging monitoring of a anti-angiogenesis therapeutic gene vasostatin in tumor cell PC3].

OBJECTIVE: To generate a sensitive tool for noninvasive monitoring of a therapeutic gene vasostatin. METHODS: 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. RESULTS: 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. CONCLUSION: Noninvasive monitoring facilitates the detection of gene expression in vivo and in vitro.

Common SNPs of APM1 gene are not associated with hypertension or obesity in Chinese population.

OBJECTIVE: To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity (HO) and related clinical features in Chinese Han population. METHODS: A case-control study design was applied. Common polymorphisms of 45T/G and 276G/T were genotyped by PCR product sequencing in 484 cases with HO and 502 controls with normal blood presure and BMI < 25. RESULTS: The genotype and allele frequencies of 45T/G, 276G/T, and haplotype defined by the two variants in cases did not differ from those in controls. The means of blood pressure, BMI and waist-hip ratio did not differ among genotypes of the two polymorphisms and haplotypes. Among lipid profiles, only serum high-density lipoprotein cholesterol (HDL-C) levels were significantly lower in T allele carriers than that in non-T carriers after adjusting possible confounding factors (1.21 vs 1.32 mmol/L, P=0.0001). CONCLUSION: Polymorphisms of 45T/G and 276G/T in APM1 gene are not associated with hypertension or obesity, or their clinical features in Chinese Han population. Common polymorphism of 45T/G might be associated with serum HDL-C levels in Chinese.

Paraoxonase gene cluster variations associated with coronary heart disease in Chinese Han women.

BACKGROUND: The oxidative modification of low-density lipoprotein in the artery wall is currently believed to be central to the pathogenesis of atherosclerosis. Paraoxonase (PON1), an enzyme located on high-density lipoprotein (HDL), can prevent low-density lipoprotein (LDL) from oxidation at a certain extent. Recent studies show two other members of paraoxonase gene family, PON2 and PON3, possess antioxidant properties similar to PON1. The aim of the present study was to explore the role of PON gene cluster on coronary heart disease (CHD) in Chinese Han women. METHODS: Seven polymorphisms including PON1 -107C > T, -162G > A, -831G > A, R160G, Q192R, PON2 S311C, and PON3 -133C > A were genotyped in 184 female patients with CHD and 239 female controls. The plasma PON1 activity toward phenylacetate was determined in 50 cases and 50 controls randomly selected. RESULTS: The plasma PON1 activities were significantly lower in cases than in controls. Individual SNP analysis showed that cases had significantly higher frequencies of PON1 -107T, -831G and PON2 311S alleles than controls. The genotype distributions of -107C > T were also significantly different between two groups. The odds ratios for the development of CHD were 1.66 for -107TC carriers and 2.0 for -107TT carriers, compared with -107CC carriers. Haplotype analyses showed that the distributions of haplotypes comprised of PON1 -107C > T and PON2 S311C were significantly different between cases and controls, with cases having higher frequency of T-S haplotype (44.8% vs. 36.3%, P = 0.013). The T-S haplotype remained significantly associated with CHD after adjusting environmental risk factors (P = 0.0069). CONCLUSIONS: This association study suggested that lower plasma PON1 activity increased the risk of CHD in Chinese women, which may be mediated by the higher frequency of -107T allele in cases. Haplotype analyses indicated that there might be some synergistic effects between the PON1 -107C > T and PON2 S311C polymorphisms.

[Recombinant human pigment epithelium-derived factor inhibits the proliferation of the endothelial cells from blood vessels].

OBJECTIVE: To express and purify the recombinant human pigment epithelium-derived factor (PEDF) which inhibits the proliferation of the endothelium cells from blood vessel in E.coli. METHODS: PEDF gene was inserted into the prokaryotic expression vector pGEX-4T-2. The recombinant protein PEDF was expressed in E.coli BL-21, and purified by the GST Sepharose 4B affinity column. The recombinant human PEDF protein was identified by Western blot and mass spectrum. The biological activity of the recombinant human PEDF protein was measured by using MTT. RESULTS: The 46 kDa recombinant human PEDF protein was obtained. It significantly inhibited the proliferation of the human umbilical vein cell line HUVEC. CONCLUSION: The recombinant human PEDF with anti-angiogenesis activity protein may be successfully purify through prokaryotic expression.

Protein kinase C/zeta (PRKCZ) gene is associated with type 2 diabetes in Han population of North China and analysis of its haplotypes.

AIM: To identify the susceptible gene (s) for type 2 diabetes in the previously mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes. METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Han ethical origin, to perform this case-control study. The haplotypes with significant difference in the gene (s) were further analyzed. RESULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP, rs436045 in the protein kinase C/zetagene (PRKCZ) was statistically different between the case and control groups(P<0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified. CONCLUSION: PRKCZ gene may be associated with type 2 diabetes in Han population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.

[Cloning and expression of human calcyclin binding protein (hCacyBP) gene].

Human calcyclin binding protein (hCacyBP) gene was obtained by the screening of a human cDNA library. The full coding region of CacyBP was cloned into E.coli strain pET28, and then was expressed and purified through affinity chromatography. Rabbit anti-human CacyBP polyclonal antibody was obtained by immunizing rabbit with the purified human CacyBP. Western blots showed that it was expressed extensively in many tissues of mouse. The results of immunohistochemistrial staining showed that the location of CacyBP in BT325 cell line before and after differentiation changed from cytoplasm into nucleus and perinucleus cytoplasm.

Single nucleotide polymorphisms in CAPN10 gene of Chinese people and its correlation with type 2 diabetes mellitus in Han people of northern China.

OBJECTIVE: To investigate the distribution of single nucleotide polymorphisms (SNPs) in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus in Han people of Northern China. METHODS: CAPN10 gene was sequenced to detect SNPs in different nationalities of China. Five SNPs were chosen to perform case-control study and haplotype analysis in 156 normal Han people of Northern China and 173 type 2 diabetes. One SNP was also analyzed with transmission-disequilibrium test (TDT) and sib transmission-disequilibrium test (STDT) in 68 type 2 diabetes pedigrees (377 people). RESULTS: A total of 40 SNPs were identified in length of 8,936 bp, with an average of 1 in every 223 bp. The SNPs in CAPN10 gene did not distribute evenly and the SNPs in Chinese were different from those reported in Mexican American. There was no significantly statistical difference in the allele frequency of the 5 SNPs between case and control, and the haplotype frequencies in the two groups were not significantly different. No positive results was found in TDT and STDT analysis. CONCLUSIONS: The SNP distribution of CAPN10 gene differs in different nationalities. The studied SNPs in CAPN10 gene may not be the major susceptibility ones of type 2 diabetes mellitus in Han people of Northern China.

[The cloning and prokaryotic expression of human tumor necrosis factor like protein].

OBJECTIVE: To identify and clone the gene encoding human TNFLP (tumor necrosis factor like protein) for some functional study on TNFLP. METHODS: The full-length cDNA of TNFLP was isolated from fetal brain cDNA library. Several kinds of software were used to analyze nucleotide sequence and amino acid sequence of TNFLP. TNFLP mRNA distribution was identified by Northern blot. TNFLP-C and TNFLP-N were expressed in E. coli with GST expression system. RESULTS: The cDNA of human TNFLP was 2,112 bp, which encoded protein of 208 amino acid. Hydrophobility analysis found there were two hydrophobility regions of human TNFLP. TNFLP-C (112-207 amino acid) and mouse TNF-alpha were homologous. The identity of their amino acid sequence was 42%. Moreover, both of them had a motif-TYKRL. TNFLP was located in chromosome 16. Human TNFLP was widely expressed in various human tissues. Northern blot showed TNFLP was highly expressed in heart, brain and spleen, only one transcript can be seen. GST-TNFLP-C and GST-TNFLP-N fusion proteins were obtained. CONCLUSIONS: Tissue expression spectrum of TNFLP and prokaryotic expression of TNFLP have been done, which establish the base for the functional analysis of TNFLP.

[Cloning, expression and purification of neural specific HuD cDNA].

OBJECTIVE: To prokaryoticly express and purify HuD protein and its RNA recognition motifs. METHODS: HuD protein was prokaryoticly expressed and purified by molecular cloning technology. Its biologic activity was testified by Western Blot. RESULTS: Purified HuD protein and its RNA recognized motifs were observed. CONCLUSIONS: The result might aid for basic research and clinical application.

[The identification and cloning of human M961 full-length cDNA and its splicing isoform].

OBJECTIVE: To identify and clone the gene encoding human M96 gene and study its expression spectrum in several blood cell lines. METHODS: According to the sequence of human EST which was highly homologous to the mouse M96 gene, primers used for library screening were synthesized, then the human adult testis and fetal brain cDNA library were screened. The gene was analyzed by making use of BLAST and CLUSTAL W, and its expression spectrum was studied by multiple-cell lines Northern blot analysis. The expression change of M961 in cell differentiation was observed by use of K562 cell line induced by hemin. RESULTS: Two cDNA clones encoding human M96 gene were isolated, identified and named as M961, and M962. They were found to be isoforms of each other. Northern, blot showed that M961 gene was expressed highly in CEM, Hel, Dami and K562 cell lines. However, during K562 cell line differentiation, process the expression of M961 elevated only slightly. CONCLUSIONS: M961 gene was expressed highly in pluripotent cell lines with erythrocytic and megakaryocytic potentials.

[Isolation and identification of SARS-coronavirus in nasal and throat swabs collected from clinically diagnosed SARS patients].

OBJECTIVE: To isolate and identify SARS-coronavirus in nasal and throat swabs collected from clinically diagnosed severe acute respiratory syndrome (SARS) patients. METHODS: Nasal and throat swab specimens were inoculated onto well of 24-well plate containing confluent monolayers of Vero and MRC-5 cells. Isolates were identified with serology, electron microscopy and genome sequence. RESULTS: One hundred and fifty-eight nasal and throat swabs specimens from 79 SARS patients in Peking Union Medical College Hospital between April and May, 2003 were cultured for SARS-coronavirus. Cytopathic effect (CPE) was found in three nasal swab specimens inoculated in Vero cells. Acute and convalescent phase serum specimens collected from SARS patients were found with seroconversions and/or a fourfold or greater rises in indirect fluorescence antibodies (IgG and IgM) titers when the 3 isolates (infected Vero cells) were used as antigen. Coronavirus was observed in the culture supernatant by negative-stain electron microscopy. Genome sequence confirmed the isolates were SARS-coronavirus. CONCLUSIONS: The 3 isolates from nasal and throat swabs samples collected from 79 clinically diagnosed SARS patients were SARS coronavirus.