Identification of hub genes associated with Helicobacter pylori infection and type 2 diabetes mellitus:A pilot bioinformatics study

BACKGROUND Helicobacter pylori(H.pylori)infection is related to various extragastric diseases including type 2 diabetes mellitus(T2DM).However,the possible mechanisms connecting H.pylori infection and T2DM remain unknown.AIM To explore potential molecular connections between H.pylori infection and T2DM.METHODS We extracted gene expression arrays from three online datasets(GSE60427,GSE27411 and GSE115601).Differentially expressed genes(DEGs)commonly present in patients with H.pylori infection and T2DM were identified.Hub genes were validated using human gastric biopsy samples.Correlations between hub genes and immune cell infiltration,miRNAs,and transcription factors(TFs)were further analyzed.RESULTS A total of 67 DEGs were commonly presented in patients with H.pylori infection and T2DM.Five significantly upregulated hub genes,including TLR4,ITGAM,C5AR1,FCER1G,and FCGR2A,were finally identified,all of which are closely related to immune cell infiltration.The gene-miRNA analysis detected 13 miRNAs with at least two gene cross-links.TF-gene interaction networks showed that TLR4 was coregulated by 26 TFs,the largest number of TFs among the 5 hub genes.CONCLUSION We identified five hub genes that may have molecular connections between H.pylori infection and T2DM.This study provides new insights into the pathogenesis of H.pylori-induced onset of T2DM.

Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems

Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations.

Pathogenesis of chronic enteropathy associated with the SLCO2A1 gene:Hypotheses and conundrums

Chronic enteropathy associated with the SLCO2A1 gene(CEAS)is a complex gastroenterological condition characterized by multiple ulcers in the small intestine with chronic bleeding and protein loss.This review explores the potential mechanisms underlying the pathogenesis of CEAS,focusing on the role of SLCO2A1-encoded prostaglandin transporter OATP2A1 and its impact on prostaglandin E2(PGE2)levels.Studies have suggested that elevated PGE2 levels contribute to mucosal damage,inflammation,and disruption of the intestinal barrier.The effects of PGE2 on macrophage activation and Maxi-Cl channel functionality,as well as its interaction with nonsteroidal anti-inflammatory drugs play crucial roles in the progression of CEAS.Understanding the balance between its protective and pro-inflammatory effects and the complex interactions within the gastrointestinal tract can shed light on potential therapeutic targets for CEAS and guide the development of novel,targeted therapies.

Detections of mefA, ermB, and mphA Macrolides Resistant Genes in Bacteria Isolated from Covid-19 Patients from Selected Health Facilities in Ibadan, Nigeria

Background: COVID-19 is a disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Epidemiological data indicated that bacterial complications in COVID-19 would decrease clearance rate of the infecting agent and increase mortality rate. Macrolides such as Azithromycin are usually administered to COVID-19 patients as palliative treatments. Currently, a considerable number of bacterial strains have developed resistance to various antibiotics, especially macrolides. Resistance is reported to be due to possession of mefA, ermB, and mphA genes by Gram positive and Gram negative bacteria. Therefore, this study determined antibiotic resistance patterns and identify mefA, ermB and mphA macrolide-resistant genes in bacterial pathogens isolated from COVID-19 cases in Ibadan, Nigeria. Methods: 400 Nasopharyngeal samples were collected from symptomatic cases before antibiotic medication;structured questionnaires were administered to collect socio-demographic data of participants. Samples were cultured on Blood, Chocolate, MacConkey and Mannitol salt agar at 37°C for 48 hrs. Bacterial identification was performed using VITEK 2.0 ID cards and API 20E for Gram positive and negative bacteria respectively. Antibiotic Susceptibility Testing was performed using Kirby Bauer disc diffusion methods and VITEK 2.0 AST card kits. DNA of multidrug resistant bacterial isolates was extracted;resistant genes were determined using a polymerase chain reaction with specific primers. Amplified genes were detected using agarose gel electrophoresis. Results: 240 (60%) had bacterial growth and 97 (22.2%) yielded no growth. From the 240 bacterial isolates, 38 (15.83%) were multi-drug resistant including resistance to macrolides (Azithromycin) 20 (52.63%) of which were positive for either mefA or ermB, and none (0.0%) possess mphA gene;14 (36.8%) isolates had mefA gene, 10 (26.3%) isolates carried ermB gene. Conclusion: Multi-drug bacterial resistance including macrolides and quinolones was detected. Only mefA and ermB genes were detected in the bacterial isolates, especially in Gram positive organisms. The detection of mefA and ermB genes in the MDR bacterial isolates raised concern on the use of azithromycin as palliative treatment for COVID-19 symptomatic patients.

Trifunctional Cu-Mesh/Cu_(2)O@FeO Nanoarrays for Highly Efficient Degradation of Antibiotic, Inactivation of Antibiotic-Resistant Bacteria, and Damage of Antibiotics Resistance Genes

Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully applied to efficiently mitigate the antibiotic pollution,including degradation of antibiotics,inactivation of antibiotic-resistant bacteria(ARB),and damage of antibiotics resistance genes(ARGs).Under visible-light irradiation,CM/CuCu_(2)O@FeO nanoarrays exhibit a superior degradation efficiency on antibiotics(e.g.,up to 99%in 25 min for tetracycline hydrochloride,TC),due to the generated reactive oxygen species(ROS),especially the dominant·O^(2−).It can fully inactivate E.coli(HB101)with initial number of~108 CFU mL^(−1) in 10 min,which is mainly attributed to the synergistic effects of 1D nanostructure,dissolved metal ions,and generated ROS.Meanwhile,it is able to damage ARGs after 180 min of photodegradation,including tetA(vs TC)of 3.3 log 10,aphA(vs kanamycin sulfate,KAN)of 3.4 log 10,and tnpA(vs ampicillin,AMP)of 4.4 log 10,respectively.This work explores a green way for treating antibiotic pollution under visible light.

Identification of key genes and biological pathways in lung adenocarcinoma by integrated bioinformatics analysis

BACKGROUND The objectives of this study were to identify hub genes and biological pathways involved in lung adenocarcinoma(LUAD)via bioinformatics analysis,and investigate potential therapeutic targets.AIM To determine reliable prognostic biomarkers for early diagnosis and treatment of LUAD.METHODS To identify potential therapeutic targets for LUAD,two microarray datasets derived from the Gene Expression Omnibus(GEO)database were analyzed,GSE3116959 and GSE118370.Differentially expressed genes(DEGs)in LUAD and normal tissues were identified using the GEO2R tool.The Hiplot database was then used to generate a volcanic map of the DEGs.Weighted gene co-expression network analysis was conducted to cluster the genes in GSE116959 and GSE-118370 into different modules,and identify immune genes shared between them.A protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database,then the CytoNCA and CytoHubba components of Cytoscape software were used to visualize the genes.Hub genes with high scores and co-expression were identified,and the Database for Annotation,Visualization and Integrated Discovery was used to perform enrichment analysis of these genes.The diagnostic and prognostic values of the hub genes were calculated using receiver operating characteristic curves and Kaplan-Meier survival analysis,and gene-set enrichment analysis was conducted.The University of Alabama at Birmingham Cancer data analysis portal was used to analyze relationships between the hub genes and normal specimens,as well as their expression during tumor progression.Lastly,validation of protein expression was conducted on the identified hub genes via the Human Protein Atlas database.RESULTS Three hub genes with high connectivity were identified;cellular retinoic acid binding protein 2(CRABP2),matrix metallopeptidase 12(MMP12),and DNA topoisomerase II alpha(TOP2A).High expression of these genes was associated with a poor LUAD prognosis,and the genes exhibited high diagnostic value.CONCLUSION Expression levels of CRABP2,MMP12,and TOP2A in LUAD were higher than those in normal lung tissue.This observation has diagnostic value,and is linked to poor LUAD prognosis.These genes may be biomarkers and therapeutic targets in LUAD,but further research is warranted to investigate their usefulness in these respects.

Role of p53 suppression in the pathogenesis of hepatocellular carcinoma

In the world,hepatocellular carcinoma(HCC)is among the top 10 most prevalent malignancies.HCC formation has indeed been linked to numerous etiological factors,including alcohol usage,hepatitis viruses and liver cirrhosis.Among the most prevalent defects in a wide range of tumours,notably HCC,is the silencing of the p53 tumour suppressor gene.The control of the cell cycle and the preservation of gene function are both critically important functions of p53.In order to pinpoint the core mechanisms of HCC and find more efficient treatments,molecular research employing HCC tissues has been the main focus.Stimulated p53 triggers necessary reactions that achieve cell cycle arrest,genetic stability,DNA repair and the elimination of DNA-damaged cells’responses to biological stressors(like oncogenes or DNA damage).To the contrary hand,the oncogene protein of the murine double minute 2(MDM2)is a significant biological inhibitor of p53.MDM2 causes p53 protein degradation,which in turn adversely controls p53 function.Despite carrying wt-p53,the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway.High p53 in-vivo expression might have two clinical impacts on HCC:(1)Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways;and(2)Exogenous p53 makes HCC susceptible to various anticancer drugs.This review describes the functions and primary mechanisms of p53 in pathological mechanism,chemoresistance and therapeutic mechanisms of HCC.

Identification and Expression Analysis of Abscisic Acid Signal Transduction Genes in Hemp Seeds

Abscisic acid(ABA)is involved in regulating diverse biological processes,but its signal transduction genes and roles in hemp seed germination are not well known.Here,the ABA signaling pathway members,PYL,PP2C and SnRK2 gene families,were identified from the hemp reference genome,including 7 CsPYL(pyrab-actin resistance1-like,ABA receptor),8 CsPP2CA(group A protein phosphatase 2c),and 7 CsSnRK2(sucrose nonfermenting1-related protein kinase 2).The content of ABA in hemp seeds in germination stage is lower than that in non-germination stage.Exogenous ABA(1 or 10μM)treatment had a significant regulatory effect on the selected PYL,PP2C,SnRK2 gene families.CsAHG3 and CsHAI1 were most significantly affected by exogenous ABA treatment.Yeast two-hybrid experiments were performed to reveal that CsPYL5,CsSnRK2.2,and CsSnRK2.3 could interact with CsPP2CA7 and demonstrate that this interaction was ABA-independent.Our results indicated that CsPYL5,CsSnRK2.2,CsSnRK2.3 and CsPP2CA7 might involve in the ABA signaling transduction pathway of hemp seeds during the hemp seed germination stages.This study suggested that novel genetic views can be brought into investigation of ABA signaling pathway in hemp seeds and lay the foundation for further exploration of the mechanism of hemp seed germination.

Study of pathogenic genes in a pedigree with familial dilated cardiomyopathy

BACKGROUND Dilated cardiomyopathy(DCM)is a genetically heterogeneous cardiac disorder characterized by left ventricular dilation and contractile dysfunction.The substantial genetic heterogeneity evident in patients with DCM contributes to variable disease severity and complicates overall prognosis,which can be very poor.AIM To identify pathogenic genes in DCM through pedigree analysis.METHODS Our research team identified a patient with DCM in the clinic.Through invest-igation,we found that the family of this patient has a typical DCM pedigree.High-throughput sequencing technology,next-generation sequencing,was used to sequence the whole exomes of seven samples in the pedigree.RESULTS A novel and potentially pathogenic gene mutation-ANK2p.F3067L-was discovered.The mutation was completely consistent with the clinical information for this DCM pedigree.Sanger sequencing was used to further verify the locus of the mutation in pedigree samples.These results were consistent with those of high-throughput sequencing.CONCLUSIONS ANK2p.F3067L is considered a novel and potentially pathogenic gene mutation in DCM.

EXPRESSION OF THE RETINOIC ACID RECEPTORS(RARs)AND RETINOID X RECEPTOR(RXRs)GENES IN BREAST CANCER

A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer cells. We examined retinoic acid receptors (RARs) and retinoids X receptors (RXRs) levels in 6 breast carcinoma cell lines and 18 breast cancer biopsy specimens. We found that RAR-α mRNA level was significantly higher in ER positive cell lines and samples. RAR-γ mRNA was expressed at relatively high levels in majority of tumor samples independent of the ER-status while RAR-β mRNA was expressed at low levels. We also found high RXR-α mRNA levels in all of the tumor samples examined while RXR-γ mRNA could not be detected. Our study suggests a possibility that retinoids inhibit tumor cell growth through RAR-a and RAR-α levels may serve as a potential marker to determine responsiveness of patients to retinoids therapy.

Impact of homeobox genes in gastrointestinal cancer

Homeobox genes, including HOX and non-HOX genes, have been identified to be expressed aberrantly in solid tumors. In gastrointestinal(GI) cancers, most studies have focused on the function of non-HOX genes including caudal-related homeobox transcription factor 1(CDX1) and CDX2. CDX2 is a crucial factor in the development of pre-cancerous lesions such as Barrett's esophagus or intestinal metaplasia in the stomach, and its tumor suppressive role has been investigated in colorectal cancers. Recently, several HOX genes were reported to have specific roles in GI cancers; for example, HOXA13 in esophageal squamous cell cancer and HOXB7 in stomach and colorectal cancers. HOXD10 is upregulated in colorectal cancer while it is silenced epigenetically in gastric cancer. Thus, it is essential to examine the differential expression pattern of various homeobox genes in specific tumor types or cell lineages, and understand their underlying mechanisms. In this review, we summarize the available research on homeobox genes and present their potential value for the prediction of prognosis in GI cancers.

PCR Detection of Virulence Genes Colv,Stxs and HlyE of Escherichia coli

[Objective] This study aimed to explore the presence of three causative genes Colv,Stxs and HlyE of the pathogenic E.coli from chickens,pigs and food.[Method] By using 44 E.coli strains from chickens,24 from pigs and 26 from food as the experimental materials,virulence genes Colv,Stxs（stx2,stx2e） and HlyE were detected with polymerase chain reaction（PCR） method.[Result] Among all the E.coli strains,the detection rate of Colv was 25% from chickens,4.2% from pigs,and 0 from food;the detection rate of Stx2（Stx2e） from all E.coli strains was 0;the detection rate of HlyE was 2.27% from chickens,0 from pigs,and 11.5% from food.[Conclusion] Virulence gene Colv shows relatively high carrying rate in E.coli from chickens and pigs;HlyE also shows a certain degree of presence in E.coli from chickens and food.

Sequence Analysis of HA Genes from Three H9N2 Subtype Avian Influenza Viruses

[ Objective] The study aimed to understand the genetic characters of H9N2 subtype avian influenza viruses isolated in Belling area. [ Method] HA genes of three H9N2 subtype avian influenza viruses A/Chicken/Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/ liu/00 were amplified by RT-PCR and then sequenced. [ Result] The results of phylogenetic analysis showed that A/Chicken/Beijing/xu/00, A/ Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 shared the nucleotide homologies of 84.8% （ Dk/HK/Y439/97 ） -98.0% （ Ck/GX17/00 ）, 85.1% （Dk/HK/Y439/97） - 99.1% （ Ck/GXl 7/00）, 90.7% （ Ck/BJ/3/01 ） - 99.1% （Ck/GX17/00） with the isolates from Hongkong and other are- as of Chinese Mainland respectively. At the same time, the analysis of amino acid indicated that the three isolates belonged to low pathogenic H9N2 isolates of avian origin. The 226^th amino acid of them were L （ Leu）, suggesting their high binding affinity to human cells. There were seven glyco- sylation sites in HA protein, five from HA1 and two from HA2. [ Cenclusien] By analysis at molecular level, it could be concluded that A/Chicken/ Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 were low pathogenic H9N2 isolates of avian origin.

The Role of Predominant Expression of Th2 Type Cytokines Gene in the Genesis and Development of Human Gliomas

Objective: To explore the expression of Th1/Th2 cytokines gene in human gliomas and its role in the genesis and development of human gliomas.Methods: Using IL-2 and IFNγ as Th1 type cytokines, IL-4, IL-6 and IL-10 as Th2 type cytokines, the biological activity of cytokines in the supernatant of glioma cell lines was assayed by ELISA method, and the gene expression of Th1/Th2 cytokines in human glioma cells, glioma infiltrating lymphocytes and glioma cell lines were detected by RT-PCR.Results: There was predominant expression of Th2 type cytokines in human glioma cells, glioma infiltrating lymphocytes and glioma cell lines, but there was no such expression in normal brain tissues.Conclusion: It suggested that there is a relationship between the Th2 type cytokines expression in human gliomas and the immunosupressive status of human glioma patients. The predominant expression of Th2 type cytokines may play an important role in the genesis and development of human gliomas. Key words glioma - Th1/Th2 - gene expression - RT-PCR This project was supported by a grant from National Natural Sciences foundation of China (No. 30271335).

RARS2基因变异一家系报告并文献复习

目的探讨RARS2基因变异的临床特点。方法回顾分析一家系2例RARS2基因变异患儿的临床资料,并复习相关文献。结果2例患儿为姐妹,均于4月龄起病,表现为喂养困难、顽固性局灶性癫痫发作、四肢肌张力减低、小头畸形,血乳酸一过性升高;头颅磁共振示双侧大脑半球萎缩,右侧颅板下出血,右侧基底节区异常信号。先证者检测到RARS2基因复合杂合变异,NM_020320 c.1157G>T(p.R 386L),NM_020320 c.1210A>G(p.M 404V)。先证者姐姐首次基因检测无发现,再次分析发现RARS2基因同样变异,并于1岁4月龄死亡。检索到相关文献19篇,包括本家系2例共37例患儿。其中男37.2%、女62.8%,大多在6月龄内起病;临床表现有癫痫发作,精神运动发育停滞或倒退,喂养困难,肌张力减低,小头畸形;大部分患儿血、脑脊液乳酸增高及脑桥小脑发育不良。共发现RARS 2基因33个变异位点。结论RARS2基因变异的临床表现有顽固性癫痫发作、喂养困难、精神运动发育迟滞或倒退、小头畸形、肌张力减低,部分患儿无桥脑小脑发育不良,预后差。

The relationship of Imp2 and DR3 genes with susceptibility to type Ⅰ diabetes mellitus in south China Han population

AIN To study the relationship of Imp2 and DR3genes with type Ⅰ diabetes mellitus.NETHODS Imp2 genotypes and DR3 wereidentified in 68 patients with type Ⅰ diabetesmellitus(Ⅰ-DM)and 71 healthy controls.Then,Ⅰ-DM patients and controls were respectivelyallocated into DR3-positive and DR3-negativegroups.The frequencies of Imp2 and DR3 genein random subjects,and Imp2 genotypes in DR3-matched subjects were compared between Ⅰ-DMpatients and controls.At the same time,Ⅰ-DMpatients were divided into 3 groups based on theonset age of diabetics:group A≤14 years,group B 15-30 years and group C≥31 years.RESULTS The frequency of DR3 in Ⅰ-DMpatients was significantly higher than that incontrols(47% vs 21%,P【0.005),and it wassignificantly higher in group A than that in groupB+C(70% vs 36%,x^2=7.07,P【0.01).Therewas a significant difference among groups withdifferent onset age of diabetics(x^2=8.19,rp=0.33,P【0.05).In random subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(43% vs 61%,P【0.05)and Imp2.R/Hhigher(53% vs 28%,P【0.05)than that incontrols,and there was no significant differenceamong groups with different onset age ofdiabetics.In DR3-positive subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(47% vs 87%,P【0.05)and Imp2-R/H higher(47% vs 13%,P【0.05)than that incontrols.In DR3-negative subjects,thefrequency of Imp2.R/H in Ⅰ-DM patients washigher than that in controls(58% vs 32%,P【0.01),but the frequency of Imp2-R/R and Imp2H/H was not significantly different betweenthese two groups.CONCLUSION DR3 gene may be one of thesusceptible genes of Ⅰ-DM,and significantlyrelated to the onset age of diabetics,and thepersons with DR3 may have an younger onsetage of diabeteS.The Imp2-R/R may be theprotective genotype of Ⅰ-DM,and Imp2-R/H thesusceptible genotype.These were not affectedby DR3 gene.Imp-2 genotypes were not relatedwith the onset age of diabetics.

Effects of epinephrine on angiogenesis-related gene expressions in cultured rat cardiomyocytes

Epinephrine is often used for the treatment of patients with heart failure, low cardiac output and cardiac arrest. It can acutely improve hemodynamic parameters; however, it does not seem to improve longer term clinical outcomes. Therefore, we hypothesized that epinephrine may induce unfavorable changes in gene expression of cardiomyocyte. Thus, we investigated effects of epinephrine exposure on the mediation or modulation of gene expression of cultured cardiomyocytes at a genome-wide scale. Our investigation revealed that exposure of cardiomyocytes to epinephrine in an in vitro environment can up-regulate the expression ofangiopoietin-2 gene （~ 2.1 times）, and down-regulate the gene expression of neuregulin 1 （-3.7 times）, plasminogen activator inhibitor-1 （-2.4 times） and SPARC-related modular calcium-binding protein-2 （-4.5 times）. These changes suggest that epinephrine exposure may induce inhibition of angiogenesis-related gene expressions in cultured rat cardiomyocytes. The precise clinical significance of these changes in gene expression, which was induced by epinephrine exposure, warrants further experimental and clinical investigations.

PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

Sequence Analysis of Type III Effector tccP and tccP2 Genes in Escherichia coli O157:H7 from Chinese Water-chestnut

[Objective] This study aimed to analyze the type III effector tccP and tccP2 genes in Escherichia coli O157：H7 from Chinese water-chestnut. [Method] Gene-specific and locus-specific primers were utilized to amplify tccP/tccP2 and their flanking regions for sequence analysis. [Result] E. coli O157：H7 CWN11 harbored intact tccP and tccP2 genes, however, the number of proline-rich repeats in tccP gene was only one that probably resulted in biological incapability, whereas, the tccP2 gene consisted of five and half proline-rich repeats and could encode functional protein. [Conclusion] Here, we reported the first sequence of tccP gene that consisted of only one proline-rich repeat and tccP2 was assumed to play a crucial role in colonization and subsequent signaling cascades.

Cloning and Phylogenetic Analysis of NS1 Genes from Different Isolates of H9N2 Subtype Duck Influenza Virus

[ Objective] The study aimed to lay a foundation for the further studies on function mechanism of NS1 protein in the interspecies transmission of waterfowl influenza virus. [Method] Using the serologic assay and the specific RT-PCR method, some strains of H9 subtype waterfowl influenza virus were isolated from the 12 to 20 day-old muscovy duck flocks without any clinical symptoms in different areas of Guangdong Province. Four of these strains, including A/duck/ZQ/303/2007（H9N2） （A3 for short）, A/Duck/FJ/301/2007 （H9N2） （C1 for short）, A/Duck/NH/306/2007（H9N2） （ D6 for short）, A/duck/SS/402/2007（H9N2） （ E2 for short）, and a strain named A/duck/ZC/2007（H9N2） （L1 for short） from a muscovy duck died of avian influenza virus （AIV）, were used for NSl gene cloning and sequencing. Subsequently, the obtained NSl gene sequences were compared with other NS1 sequences registered in GenBank, and the phylogenetic analysis was also conducted. [Result] When compared with the H9N2 AIV NS1 sequences in GenBank, the NSl genes of the four AIV strains A3, C1, 136 and E2 displayed homologies ranging from 99% to 100% at nucleotide level, and 95% to 100% at amino acid level; while the NSl gene of L1 strain displayed homology ranging from 94% to 97% at nucleotide level, and 93% to 98% at amino acid level. The phylogenetic tree demonstrated that A3, C1, D6 and E2 were highly resemblant, and L1 was closest to AY66473 （chicken, 2003）. By comparison with the NS1 gene sequences of L1, AF523514 （duck）, AY664743 （chicken） and EF155262.1 （quail） using DNAstar, A3, C1, D6 and E.2 presented nucleotide variations at site 21 （ R→Q）, 70, 71 （ KE→EG）, 86 （ A→S）, 124 （V→M） and 225 （ S→N）, and amino acid variations at site 21,70, 71 and 86 in dsRNA- dependent protein kinase （PKR） binding domain of NSl gene, which induced the evident variations of antigenic determinant and surface proba- bility plot of NS1 protein. [ Conclusion] This study suggested that the amino acid sequence variation in PKR binding domain of NS1 protein had something to do with the virus pathogenicity.