Understanding the catalytic performance and deactivation behaviour of second-promoter doped Pt/WO_(χ)/γ-Al_(2)O_(3) catalysts in the glycerol hydrogenolysis for selective and cleaner production of 1,3-propanediol

The selective aqueous-phase glycerol hydrogenolysis is a promising reaction to produce commercially useful 1,3-propanediol(1,3-PDO).The Pt-WOx bifunctional catalyst can catalyse the glycerol hydrogenol-ysis but the catalyst deactivation via sintering,metal leaching,and coking can predominantly occur in the aqueous phase reaction.In this work,the effect of reaction temperature,pressure and second promoter(Cu,Fe,Rh,Mn,Re,Ru,Ir,Sn,B,and P)on catalytic performance and deactivation behaviour of Pt/WOx/-Al2O3 was investigated.When doped with Rh,Mn,Re,Ru,Ir,B,and P,the second promoter boosts catalytic activity by promoting great dispersion of Pt on support and increasing Pt surface area.The increased Bronsted acid sites lead to selective synthesis of 1,3-PDO than 1,2-propanediol(1,2-PDO).The characterization studies of fresh and spent catalysts reveal that the main cause of catalyst deactivation is the Pt sintering,as interpreted based on XRD,CO chemisorption,and TEM analyses.The Pt sintering is affected depending on the second promoter that can either or reduce the interaction between Pt,WO_(χ)/γ and Al_(2)O_(3).As an electron acceptor of Pt in Pt/WO_(χ)/γ-Al_(2)O_(3),Re and Mn as second promoters resulted in increased Pt^(2+) on the catalytic surface,which strengthens the contact between Pt andγ-Al_(2)O_(3) and WO_(χ),resulting in a decrease in Pt sintering.The metal leaching and coking are not affected by the presence of second promoter.The catalyst modified with a second promoter possesses improved catalytic activity and 1,3-PDO production,however the stability continues to remain a challenge.The present work unrav-elled the determining parameters of catalytic activity and deactivation,thus providing a promising pro-tocol toward effective catalysts for glycerol hydrogenolysis.

Molecular cloning,characterization and promoter analysis of LbgCWIN1 and its expression profiles in response to exogenous sucrose during in vitro bulblet initiation in lily

Lily(Lilium spp.) is an important ornamental flower, which is mainly propagated by bulbs. Cell wall invertases(CWINs), which catalyze the irreversibly conversion of sucrose into glucose and fructose in the extracellular space, are key enzymes participating in sucrose allocation in higher plants. Previous studies have shown that CWINs play an essential role in bulblet initiation process in bulbous crops, but the underlying molecular mechanism remains unclear. Here, a CWIN gene of Lilium brownii var. giganteum(Lbg) was identified and amplified from genomic DNA. Quantitative RT-PCR assays revealed that the expression level of LbgCWIN1 was highly upregulated exactly when the endogenous starch degraded in non-sucrose medium during in vitro bulblet initiation in Lbg. Phylogenetic relationship, motif, and domain analysis of LbgCWIN1 protein and CWINs in other plant species showed that all sequences of these CWIN proteins were highly conserved. The promoter sequence of LbgCWIN1 possessed a number of alpha-amylase-, phytohormone-, light-and stress-responsive cis-elements. Meanwhile, β-glucuronidase(GUS) assay showed that the 459 bp upstream fragment from the translational start site displayed maximal promoter activity. These results revealed that LbgCWIN1 might function in the process of in vitro bulblet initiation and be in the response to degradation of endogenous starch.

Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters

Long-range interactions between regulatory elements and gene promoters play key roles in transcriptional regulation.The vast majority of interactions are uncharted,constituting a major missing link in understanding genome control.Here,we use promoter capture Hi-C to identify interacting regions of 31,253 promoters in 17 human primary hematopoietic cell types.We show that promoter interactions are highly cell type specific and enriched for links between active promoters and epigenetically marked enhancers.Promoter interactomes reflect lineage relationships of the hematopoietic tree,consistent with dynamic remodeling of nuclear architecture during differentiation.Interacting regions are enriched in genetic variants linked with altered expression of genes they contact,highlighting their functional role.We exploit this rich resource to connect non-coding disease variants to putative target promoters,prioritizing thousands of disease-candidate genes and implicating disease pathways.Our results demonstrate the power of primary cell promoter interactomes to reveal insights into genomic regulatory mechanisms underlying common diseases.

Functional analysis of a cotton glucuronosyltransferase promoter in transgenic tobaccos

The 5＇ fragment （1 647 bp） of the cotton glucuronosyltransferase gene （GhGlcAT1） was transcriptionally fused to the β-glucuronidase （GUS） gene, and functionally analyzed for important regulatory regions controlling gene expression in transgenic tobacco plants. GUS activity analysis revealed that the full-length promoter drives efficient expression of the GUS gene in the root cap, seed coat, pollen grains and trichomes. Exposure of the transgenic tobacco to various abiotic stresses showed that the promoter was mainly responsive to the sugars （glucose and sucrose） as well as gibberellic acid. Progressive upstream deletion analyses of the promoter showed that the region from -281 to ＋30 bp is sufficient to drive strong GUS expression in the trichomes of shoot, suggesting that the 311 bp region contains all cis-elements needed for trichome-specific expression. Furthermore, deletion analysis also revealed that the essential cis-element（s） for sucrose induction might be located between -635 and -281 bp. In addition, sequence analysis of the regulatory region indicated several conserved motifs among which some were shared with previously reported seed-specific elements and sugarresponsive elements, while others were related with trichome expression. These findings indicate that a 1 647-bp fragment of the cotton GhGIcAT1 promoter contains specific transcription regulatory elements, and provide clues about the roles of GhGIcAT 1 in cotton fiber development. Further analyses of these elements will help to elucidate the molecular mechanisms regulating the expression of the GhGlcAT1 gene during fiber elongation.

Impact of MGMT Promoter Methylation as a Prognostic Marker in Patients with High Grade Glioma: A Single-Center Observational Study

Objectives: 1) To correlate the methylation status of the O-6-methylguanine-DNA-methyltransferase (MGMT promoter gene) and response to alkylating agent-based treatment in high-grade gliomas. Background: The MGMT gene is epigenetically silenced by promoter hypermethylation in gliomas and this modification has emerged as a relevant predictor of therapeutic response. Methods: 20 cases of high-grade glioma were analyzed for MGMT promoter methylation by methylation-specific PCR. Response to treatment and overall survival data were recorded and data analysed. Results: MGMT promoter methylation was found in 60% of gliomas by methylation-specific PCR. The mean survival time of glioblastoma patients submitted to adjuvant therapy was significantly higher among patients with MGMT promoter methylation (P = 0.035) and methylation status was an independent predictive factor that was associated with improved prognosis. Discussion and Conclusion: MGMT promoter methylation status was a more reliable predictor of response to adjuvant therapy and prognosis of high-grade gliomas. A subset of patients received irinotecan and bevacizumab in the second line setting and patients with unmethylated MGMT seemed to do better than the MGMT promoter methylated group.

The relationship between Methylation of MGMT gene promoter and chemosensitivity and prognosis of non-small cell lung cancer

Objective:To detect the methylation status of MGMT gene promoter in non-small cell lung cancer(NSCLC),and to analyze the relationship between methylation of MGMT gene promoter and the chemosensitivity and prognosis of adjuvant chemotherapy after NSCLC.Methods:Tumor tissues and adjacent non-tumor tissues of 92 patients with NSCLC who underwent surgery and adjuvant chemotherapy from January 2012 to June 2015 in the thoracic surgery department of our hospital were collected,methylation-specific PCR(MSP)was used to detect the methylation status of MGMT gene promoter in tissues,and the relationship between methylation of MGMT gene promoter and chemosensitivity,progression-free survival(PFS)and 3-year overall survival rate was analyzed.Results:The methylation rate of MGMT gene promoter in cancer tissue was 39.13%(36/92)higher than that in non-cancer tissue 3.26%(3/92)(P<0.05);methylation of MGMT gene promoter was associated with TNM stage,lymph node metastasis and tumor differentiation(P<0.05);the proportion of patients with recurrence,metastasis or death in methylation group was higher than that in non-methylation group(P<0.05);PFS and 3-year overall survival rate in methylated group were lower than those in non-methylated group(P<0.05);multivariate COX regression analysis showed that lymph node metastasis and promoter methylation of MGMT gene were independent risk factors for prognosis of NSCLC patients.Conclusion:MGMT gene promoter methylation is closely related to the chemosensitivity and prognosis of platinum-based adjuvant chemotherapy after NSCLC.It may be an important target to reverse the chemosensitivity of platinum-based chemotherapy and improve the prognosis of NSCLC.

Isolation of a Genomic DNA for Gastrodia Antifungal Protein and Analyses of Its Promoter in Transgenic Tobacco

A genomic DNA containing 5'-upstream region and complete open reading frame of a Gastrodia antifungal protein was isolated by screening of a genomic library from Gastrodia elata B1. To investigate the promoter activity, the 5'-flanking region - 1 157 lip upstream from the putative transcription start site was fused to the coding sequence of beta-glucuronidase (GUS) gene and transformed into Nicotiana tabacum. The strongest GUS activity was detected in the roots of transgenic tobacco, followed by stems. The leaves only showed a low GUS activity. Furthermore, the promoter established inducible expression pattern in transgenic tobacco upon fungus Trichoderma viride inoculation and jasmonic acid and salicylic acid treatments.

Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

Cloning of Banana Bunchy Top Virus Chinese Zhangzhou Isolate DNA 4 and the Promoter Activity of Its Non_coding Region

Banana bunchy top virus Chinese Zhangzhou isolate (BBTV-ZZ) DNA 4 was amplified by PCR and cloned. Sequence analysis showed that BBTV-ZZ DNA 4 is 1 039 nucleotides (nts) in length and this virus could be one member of BBTV Asian group. Transcriptional initiation site A, which is at the 269 nucleotide, was preliminarily determined by using 5' RACE method. BBTV-ZZ DNA 4 non-coding region was sub-cloned by PCR and inserted into upstream of gfp : : gus plant expression vector pCAMBIA 1304 to construct recombinant plasmid pTA2. Agrobacterium tumefaciens harboring pTA2 was injected into leaves of the tobacco (Nicotiana tabacum L. cv. Xanthi NC) via Agrobacterium-infiltration procedure. Transient expressions of GUS and GFP were determined in injected leaves 3 - 5 d later. GUS activities of pTA2, pCAMBIA 1304 injected and non-injected tobacco leaves respectively were 1.007 0 pmol MU(.)mug(-1.)min(-1), 2.069 0 pmol MU(.)mug(-1.)min(-1) and 0.021 4 pmol MU(.)mug(-1.)min(-1). Indirect ELISA for GFP in 1 mg total protein from pTA2, pCAMBIA 1304 injected and non-injected leaves showed an A(490 nm) value of 89.577, 100.440 and 3.287, respectively. These results showed that the non-coding region of BBTV-ZZ DNA 4 has a promoter activity not only in the virus replication in monocot, but also in driving the expression of a foreign gene in dicot plants.

Highly dispersed Ni nanoparticles on 3D-mesoporous KIT-6 for CO methanation: Effect of promoter species on catalytic performance

Promoter-modified Ni-based catalysts were synthesized by an incipient-wetness impregnation method using 3D-mesoporous KIT-6 as a support modified by ethylene glycol, and evaluated for the catalytic production of synthetic natural gas （SNG） from CO methanation. Characterization results suggested that the addition of promoter species could remarkably improve the low-temperature catalytic activity for CO methanation, which was due to a large dispersion of Ni nanoparticles, an enhanced interaction between metal and support as well as a confinement effect of 3D-mesopores. Among all catalysts, Ni-V/KIT-6 possessed the best catalytic performance, which was ascribed to the largest H2 uptake of 177.6 ^mol/g and Ni dispersion of 26.5%, an intimate interaction with the support from the formation of Si-O-V linkage and an enhanced confinement effect of 3D-mesopores to effectively prevent the growth of Ni nanoparticles and carbon filaments. In consequence, Ni-V/KIT-6 displayed excellent catalytic performance as well as high catalytic stability, which can be regarded as a promising candidate for CO methanation.

电针通过调控NOS神经元改善慢性应激致肠易激综合征大鼠的内脏痛敏的研究

目的:观察电针“天枢”“足三里”“大肠俞”对慢性应激致肠易激综合征(IBS)模型大鼠粪便粒数、内脏痛敏及结肠-氧化氮合酶阳性(NOS)神经元表达的影响,探讨电针干预IBS的机制。方法:70只大鼠随机分为正常组、模型组、天枢组、足三里组和大肠俞组,每组14只。模型组、天枢组、足三里组和大肠俞组采用慢性避水应激(WAS)方法和慢性不可预测轻度应激(CUMS)法联合建立动物模型。天枢组、足三里组、大肠俞组分别电针大鼠双侧“天枢”“足三里”“大肠俞”穴。采用腹壁回撤反射(AWR)、腹直肌肌电(EMG)评估大鼠内脏敏感性,采集结肠电信号,免疫组化法、Western blot法检测结肠NOS阳性神经元表达。结果:造模后,与正常组比较,模型组大鼠粪便颗粒数先增多后减少,差异有统计学意义(P<0.05),AWR评分升高,差异有统计学意义(P<0.01),结肠慢波频率减慢,差异有统计学意义(P<0.01),腹直肌放电、结肠NOS阳性神经元和NOS蛋白表达均增多,差异有统计学意义(P<0.05)。电针治疗均可逆转上述变化,且天枢组AWR评分低于大肠俞组、足三里组,差异有统计学意义(P<0.05)。结论:电针“天枢”“足三里”“大肠俞”可通过下调结肠肌间神经网NOS阳性神经元的表达,减轻其内脏敏感性,从而恢复结肠运动,缓解肠易激症状;电针“天枢”穴对内脏敏感性的调节作用较“足三里”“大肠俞”穴更为明显。

NOS2基因DNA甲基化编辑调节NO浓度影响肌肉发育通路基因的表达

旨在探究对一氧化氮合成酶(NOS)2进行DNA甲基化编辑后对肌红蛋白的调控作用机制,并研究其对神经元一氧化氮合酶(nNOS)和内皮细胞一氧化氮合酶(eNOS)的表达水平是否有影响。本试验采用DNA甲基化编辑技术在猪肾细胞系PK-15细胞对基因NOS2进行甲基化编辑,在猪肾细胞中检测NOS2基因启动子DNA甲基化水平、NOS2表达水平、细胞内一氧化氮浓度以及肌纤维和肌红蛋白相关基因的表达。结果发现,NOS2基因启动子前500 bp区域平均DNA甲基化水平降低,但差异不显著,而gRNA2结合位点附近的CpG位点甲基化水平增高。此外,对NOS2进行甲基化编辑后,NOS2基因表达量和其iNOS蛋白质表达量显著降低。随着NOS2表达降低,nNOS和eNOS表达显著增加。MYHC-Ⅱb和MYHC-Ⅱx的表达水平显著下降,Myoglobin蛋白表达也显著下降。综上,NOS2基因的异常表达能够影响细胞中的NO生成,同时也会影响NOS1和NOS3的表达,以及和肌肉发育相关基因的表达。

Analysis of the methylation pattern of six gene promoters in sperm of men with abnormal protamination

It has recently been shown that alteration of the methylation pattern of imprinted genes is associated with different types of male infertility. The objective of our study was to investigate the methylation pattern of selected gene promoters in sperm of patients with abnormal protamine replacement. The promoters of OCT4, SOX2, NANOG, HOXC11, miR-17and CREMwere analyzed using bisulfite sequencing and the percentage of DNA methylation was compared between patients with an abnormal protamine l/protamine 2 （P1/ P2） ratio and normozoospermic controls. No significant quantitative differences were found between groups of patients with either an abnormally high or low P1/P2 ratio compared to normal controls. However, two individual samples from infertile subjects （2/20, 10%） showed an altered methylation pattern for the CREMgene promoter that was not found in control samples. These two samples had a significantly higher （P〈0.05） promoter methylation （5.58 and 4.23%, respectively） compared to the control group （0.46%）. In conclusion, in our pilot study, extreme methylations defects were not seen broadly in severely infertile men. However, two patients exhibited altered methylation of the CREMgene, which may be either causative or a result of abnormal protmaine replacement.

A novel fused iron catalyst for ammonia synthesis promoted with rare earth gangue

Rare earth gangue, which mainly consists of mixtures of light rare earths such as lanthana, ceria, neodymium oxide and praseodymium oxide, was used as the promoter of fused iron catalysts for ammonia synthesis. The result showed that the activity of the catalyst promoted with rare earth gangue was comparable with those of commercial iron catalysts with high amount of cobalt. The role of rare earths was owed to their advantages for favoring the deep reduction of the main composite in catalyst, i.e., iron oxide. This fmding indicated that the use of rare earth gangue could decrease the content of cobalt or even completely replace cobalt, which was used to be regarded as unsub- stitutable promoters for high performance ammonia catalyst; therefore, the cost of fused iron catalysts would decrease significantly.

Systematic identification of endogenous RNA polymeraseⅢpromoters for efficient RNA guidebased genome editing technologies in maize

Single-guide RNA(sg RNA) is one of the two core components of the CRISPR(clustered regularly interspaced short palindromic repeat)/Cas(CRISPR-associated) genome-editing technology. We established an in vitro Traffic Light Reporter(TLR) system, which is designated as the same colors as traffic lights such as green, red and yellow were produced in cells. The TLR can be readily used in maize mesophyll protoplast for a quick test of promoter activity. The TLR assay indicates the variation in transcription activities of the seven Pol III promoters, from 3.4%(U6-1) to over 21.0%(U6-6). The U6-2 promoter, which was constructed to drive sg RNA expression targeting the Zm Wx1 gene, yielded mutation efficiencies ranging from 48.5% to 97.1%. Based on the reported and unpublished data, the in vitro TLR assay results were confirmed to be a readily system and may be extended to other plant species amenable to efficient genome editing via CRISPR/Cas. Our efforts provide an efficient method of identifying native Pol III-recognized promoters for RNA guide-based genome-editing systems in maize.

Revalorization of CO2 for methanol production via ZnO promoted carbon nanofibers based Cu-ZrO2 catalytic hydrogenation

A series of novel carbon nanofibers(CNFs)based Cu-ZrO2 catalysts were synthesized by deposition precipitation method.To investigate the influence of promoter,catalysts were loaded with 1,2,3 and 4 wt%ZnO and characterized by ICP-OES,HRTEM,BET,N2O chemisorption,TPR,XPS and CO2-TPD techniques.The results revealed that physicochemical properties of the catalysts were strongly influenced by incorporation of ZnO to the parent catalyst.Copper surface area(SCu)and dispersion(DCu)were slightly decreased by incorporation of ZnO promoter.Nevertheless,SCuand DCuwere remarkably decreased when ZnO content was exceeded beyond 3 wt%.The catalytic performance was evaluated by using autoclave slurry reactor at a pressure and temperature of 30 bar and 180℃,respectively.The promotion of CuZrO2/CNFs catalyst with 3 wt%of ZnO enhanced methanol synthesis rate from 32 to 45 g kg^-1 h^-1.Notably,with the ZnO promotion the selectivity to methanol was enhanced to 92%compared to 78%of the un-promoted Cu-ZrO2/CNFs catalyst at the expense of a lowered CO2 conversion.In addition,the catalytic activity of this novel catalyst system for CO2 hydrogenation to methanol was compared with the recent literature data.

Downregulation of orosomucoid 2 acts as a prognostic factor associated with cancer-promoting pathways in liver cancer

BACKGROUND Liver cancer has a high mortality and morbidity rate throughout the world.In clinical practice,the prognosis of liver cancer patients is poor,and the complex reasons contribute to treatment failures,including fibrosis,hepatitis viral infection,drug resistance and metastasis.Thus,screening novel prognostic biomarkers is of great importance for guiding liver cancer therapy.Orosomucoid genes(ORMs)encode acute phase plasma proteins,including orosomucoid 1(ORM1)and ORM2.Previous studies showed their upregulation upon inflammation,but the specific function of ORMs has not yet been determined,especially in the development of liver cancer.AIM To determine the expression of ORMs and their potential function in liver cancer.METHODS Analysis of the expression of ORMs in different human tissues was performed on data from the HPA RNA-seq normal tissues project.The expression ratio of ORMs was determined using the HCCDB database,including the ratio between liver cancer and other cancers,normal liver and other normal tissues,liver cancer and adjacent normal liver tissues.Analysis of ORM expression in different cancer types was performed using The Cancer Genome Atlas and TIMER database.The expression of ORMs in liver tumor tissues and adjacent normal tissues were further confirmed using Gene Expression Omnibus data,including GSE36376 and GSE14520.The 10-year overall survival(OS),progression-free survival(PFS)and relapse-free survival(RFS)rates between high and low ORM expression groups in liver cancer patients were determined using the Kaplan-Meier plotter tool.Gene Set Enrichment Analysis(GSEA)was employed to explore the ORM2-associated signaling network.Correlations between ORM2 expression and tumor purity or the infiltration level of macrophages in liver tumor tissues were determined using the TIMER database.The correlation between ORM2 gene levels,tumor-associated macrophage(TAM)markers(including CD68 and TGFβ1)and T cell immunosuppression(including CTLA4 and PD-1)in liver tumor tissues and liver GTEx was determined using the GEPIA database.RESULTS ORM1 and ORM2 were highly expressed in normal liver and liver tumor tissues.ORM1 and ORM2 expression was significantly decreased in liver tumor tissues compared with adjacent normal tissues,and similar results were also noted in cholangiocarcinoma,esophageal carcinoma,and lung squamous cell carcinoma.Further analysis of the Gene Expression Omnibus Database also confirmed the downregulation of ORM1 and ORM2 in liver tumors.Survival analysis showed that the high ORM2 group had better survival rates in OS,PFS and RFS.ORM1 only represented better performance in PFS,but not in OS or RFS.GSEA analysis of ORM2 from The Cancer Genome Atlas liver cancer data identified that ORM2 positively associated with the G2/M checkpoint,E2F target signaling,as well as Wnt/β-catenin and Hedgehog signaling.Moreover,apoptosis,IFN-αresponses,IFN-γresponses and humoral immune responses were upregulated in the ORM2 high group.ORM2 expression was negatively correlated with the macrophage infiltration level,CD68,TGFβ1,CTLA4 and PD-1 levels.CONCLUSION The results showed that ORM1 and ORM2 were highly expressed specifically in liver tissues,whereas ORM1 and ORM2 were downregulated in liver tumor tissues.ORM2 is a better prognostic factor for liver cancer.Furthermore,ORM2 is closely associated with cancer-promoting pathways.

Cdx2 expression and its promoter methylation during metaplasia-dysplasia-carcinoma sequence in Barrett's esophagus

AIM:To examine how the expression of caudal type homebox transcription factor 2(Cdx2) is regulated in the development of malignancy in Barrett's esophagus.METHODS:Cdx2,mucin(MUC) series(MUC2,MUC5AC and MUC6),p53 and E-cadherin expression in Barrett's esophagus and adenocarcinoma specimens were examined by immunostaining.Isolated clusters of cells from(1) MUC2 and Cdx2-positive intestinal metaplastic mucosa;(2) MUC5AC and MUC6-positive,and MUC2 and Cdx2-negative high-grade dysplasia(HD),or intramucosal adenocarcinoma(IMC);and(3) MUC5AC,MUC6 and Cdx2-positive poorly-differentiated invasive adenocarcinoma(PDA) were analyzed by methylationspecific polymerase chain reaction using sets of primers for detecting methylation status of the Cdx2 gene.RESULTS:Most of the non-neoplastic Barrett's esophageal mucosa showing intestinal-type metaplasia with or without low-grade dysplasia was positive for E-cadherin,MUC series and Cdx2,but negative for p53.A portion of the low-grade to HD was positive for E-cadherin,MUC5AC,MUC6 and p53,but negative for MUC2 and Cdx2.The definite IMC area was strongly positive for MUC5AC,MUC6 and p53,but negative for MUC2 and Cdx2.Methylation of the Cdx2 promoter was not observed in intestinal metaplasia,while hypermethylation of part of its promoter was observed in hot dipped and IMC.Hypermethylation of a large fraction of the Cdx2 promoter was observed in PDA.CONCLUSION:Cdx2 expression is restored irrespective of the methylation status of its promoter.Apparent positive immunohistochemical results can be a molecular mark for gene silencing memory.

Genomic Analysis of MicroRNA Promoters and Their Cis-Acting Elements in Soybean

MicroRNAs （miRNAs） are derived from distinct loci in the genome and play crucial roles in RNA-mediated gene silencing mechanisms that regulate cellular processes during development and stress responses of plants. The miRNAs are approximately 21 nucleotides long and code for the complementary strand to a larger genic mRNA. They are often found within the complementary primary transcript （pri-miRNAs）. In the past few years, a growing number of soybean miRNAs have been discovered, however, little is known about the transcriptional regulation of these miRNAs. In this study, promoters and cis-acting elements of soybean miRNAs were analyzed using the genomic data for the first time. A total of 82 miRNAs were located among 122 loci in genome, some were present as double or multiple copies. Five clusters that included ten miRNAs were found in genome, and only one cluster share the same promoter. A total of 191 promoters from 122 loci of the soybean miRNA sequences were found and further analyzed. The results indicated that the conserved soybean miRNA genes had a greater proportion of promoters than that of non-conserved ones, and the distribution of the transcript start sites （TSSs） and TATA-boxes found had different motif styles between conserved and non-conserved miRNA genes. Furthermore, the cis-acting elements 5＇ of the TSSs were analyzed to obtain potential function and spatiotemporal expression pattern of miRNAs. The data obtained here may lead to the identification of specific sequences upstream of pre-miRNAs and the functional annotation of miRNAs in soybean.

Promoter methylation and mRNA expression of DKK-3 and WIF-1 in hepatocellular carcinoma

AIM:To investigate the promoter methylation status and mRNA expression of DKK-3 and WIF-1 gene in hepatocellular carcinoma(HCC).METHODS:DKK-3 and WIF-1 acted as Wnt-antagonists and tumor suppressors,but hypermethylation of the gene promoter and low mRNA expression activated Wnt signaling aberrantly and induced the development of HCC.Methylation status of the DKK-3 and WIF-1 gene promoter was investigated using methylation specific polymerase chain reaction(PCR) in tumor and adjacent non-cancerous tissues from 33 HCC patients and 20 normal liver tissues served as control.The expression of DKK-3 and WIF-1 mRNA was also determined by real-time quantitative reverse transcriptase PCR.The relationship between methylation,mRNA expression,and clinical data,as well as methylation and mRNA expression of the two genes were analyzed.RESULTS:The methylation of DKK-3 and WIF-1 genes in HCC increased significantly compared with adjacent non-cancerous tissues and normal control tissues(χ2 =7.79,P < 0.05;χ2 = 4.89,P < 0.05),and no significant difference in methylation between adjacent non-cancerous tissues and normal control tissues was observed.In HCC tissues,significant differences in the DKK-3 promoter methylation were observed in age and cirrhosis,and significant differences of the WIF-1 promoter methylation were observed in HBsAg and cirrhosis.The average expression of DKK-3 mRNA in HCC and adjacent non-cancerous tissues was increased significantly compared with normal control tissues.The average expression of WIF-1 mRNA showed no significant difference among the three tissues.The mRNA expression of DKK-3 gene in HCC was decreased as the pathological grade increased.CONCLUSION:The aberrant promoter methylation and decreased expression of DKK-3 and WIF-1 may be an important mechanism in HCC,and may be a far-reaching significance in early diagnosis and therapy of HCC.