High-resolution genetic mapping and identification of candidate genes for the wheat stem rust resistance gene Sr8155B1

Stem rust,caused by Puccinia graminis f.sp.tritici(Pgt),threatens global wheat production.Development of cultivars with increased resistance to stem rust by identification,mapping,and deployment of resistance genes is the best strategy for controlling the disease.In this study,we performed fine mapping and characterization of the all-stage stem rust resistance(Sr)gene Sr8155B1 from the durum wheat line 8155-B1.In seedling tests of biparental populations,Sr8155B1 was effective against six Chinese Pgt races tested.In a segregating population of 5060 gametes,Sr8155B1 was mapped to a 0.06-cM region flanked by markers Pku2772 and Pku43365,corresponding to 1.5-and 2.7-Mb regions in the Svevo and Chinese Spring reference genomes.Both regions include several typical nucleotide-binding leucine-rich repeat(NLR)and protein kinase genes that represent candidate genes.Among them,three NLR genes and three receptor-like protein kinases were highly polymorphic between the parental lines and their transcripts were upregulated in the homozygous resistant line TdR2 relative to its susceptible sister line TdS4.Four markers(Pku2772,Pku43365,Pku2950,and Pku3721)developed in this study,together with seedling resistance responses,correctly predicted Sr8155B1 absence or presence in 78 tetraploid wheat genotypes tested.The presence of Sr8155B1 in tetraploid wheat accessions CItr 14916,PI 197492,and PI 197493 was confirmed by mapping in three F_(2)populations.The genetic map and linked markers developed in this study may accelerate the deployment of Sr8155B1-mediated resistance in wheat breeding programs.

Differentially expressed genes in hepatocellular carcinoma induced by woodchuck hepatitis B virus in mice

INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.

The Effects of Dwarfing Genes (Rht-B1b, Rht-D1b, and Rht8) with Different Sensitivity to GA_3 on the Coleoptile Length and Plant Height of Wheat

Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.

Cytochrome b5 reductase 2 suppresses tumor formation in nasopharyngeal carcinoma by attenuating angiogenesis

Background:Cytochrome b5 reductase 2(CYB5R2) is a potential tumor suppressor that inhibits cell proliferation and motility in nasopharyngeal carcinoma(NPC).Inactivation of CYB5R2 is associated with lymph node metastasis in NPC.This study aimed to explore the mechanisms contributing to the anti-neoplastic effects of CYB5R2.Methods:Polymerase chain reaction(PCR) assays were used to analyze the transcription of 84 genes known to be involved in representative cancer pathways in the NPC cell line HONE1.NPC cell lines CNE2 and HONE1 were transiently transfected with CYB5R2,and data was validated by real-time PCR.A chick chorioallantoic membrane(CAM)embryo model was implanted with CYB5R2-expressing CNE2 and HONE1 cells to evaluate the effect of CYB5R2 on angiogenesis.An immunohistochemical assay of the CAM model was used to analyze the protein expression of vascular endothelial growth factor(VEGF).Results:In CYB5R2-transfected NPC cells,PCR assays revealed up-regulated mRNA levels of Fas cell surface death receptor(FAS),FBJ murine osteosarcoma viral oncogene homolog(FOS),phosphoinositide-3-kinase regulatory subunit 1(PIK3R1),integrin beta 3(ITGB3),metastasis suppressor 1(MTSSl),interferon beta 1(IFNB1),and cyclin-dependent kinase inhibitor 2A(CDKN2A) and down-regulated levels of integrin beta 5(ITGB5),insulin-like growth factor 1(IGF1),TEK tyrosine kinase(TEK),transforming growth factor beta receptor 1(TGFBRl),and VEGF.The angiogenesis in the CAM model implanted with CYB5R2-transfected NPC cells was inhibited.Down-regulation of VEGF by CYB5R2 in NPC cells was confirmed by immunohistochemical staining in the CAM model.Conclusion:CYB5R2 up-regulates the expression of genes that negatively modulate angiogenesis in NPC cells and down-regulates the expression of VEGF to reduce angiogenesis,thereby suppressing tumor formation.

Genome-wide identification and expression analysis of anthocyanin biosynthetic genes in Brassica juncea

Anthocyanins confer the wide range of colors for plants and also play beneficial health roles as potentially protective factors against heart disease and cancer. Brassica juncea is cultivated as an edible oil resource and vegetable crop worldwide, thus elucidating the anthocyanin biosynthetic pathway would be helpful to improve the nutritional quality of Brassica juncea through the breeding and cultivating of high anthocyanin content varieties. Herein, 129 genes in B. juncea were identified as orthologs of 41 anthocyanin biosynthetic genes(ABGs) in Arabidopsis thaliana by comparative genomic analyses. The B. juncea ABGs have expanded by whole genome triplication and subsequent allopolyploidizatoin, but lost mainly during the whole genome triplication between B. rapa/B. nigra and A. thaliana, rather than the allopolyploidization process between B. juncea and B. rapa/B. nigra, leading to different copy numbers retention of A. thaliana homologous genes. Although the overall expansion levels ABGs were similar to the whole genome, more negative regulatory genes were retained in the anthocyanin biosynthesis regulatory system. Transcriptional analysis of B. juncea with different anthocyanin accumulation showed that BjDFR, BjTT19, BjTT8 are significantly up-regulated in plants with purple leaves as compared with green leaves. The overexpression of BjTT8 and these target genes which were involved in late anthocyanin biosynthesis and transport might account for increasing levels of anthocyanin accumulation in purple leaves. Our results could promote the understanding of the genetic mechanism of anthocyanin biosynthesis in B. juncea.

Hepatocellular carcinoma mouse models:Hepatitis B virusassociatedhepatocarcinogenesis and haploinsufficienttumor suppressor genes

The multifactorial and multistage pathogenesis of hepatocellular carcinoma(HCC)has fascinated a wide spectrum of scientists for decades.While a number of major risk factors have been identified,their mechanistic roles in hepatocarcinogenesis still need to be elucidated.Many tumor suppressor genes(TSGs)have been identified as being involved in HCC.These TSGs can be classified into two groups depending on the situation with respect to allelic mutation/loss in the tumors:the recessive TSGs with two required mutated alleles and the haploinsufficient TSGs with one required mutated allele.Hepatitis B virus(HBV)is one of the most important risk factors associated with HCC.Although mice cannot be infected with HBV due to the narrow host range of HBV and the lack of a proper receptor,one advantage of mouse models for HBV/HCC research is the numerous and powerfulgenetic tools that help investigate the phenotypic effects of viral proteins and allow the dissection of the dose-dependent action of TSGs.Here,we mainly focus on the application of mouse models in relation to HBV-associated HCC and on TSGs that act either in a recessive or in a haploinsufficient manner.Discoveries obtained using mouse models will have a great impact on HCC translational medicine.

Determining Nodulation Regulatory (Rj) Genes of Myanmar Soybean Cultivars and Their Symbiotic Effectiveness with <i>Bradyrhizobium japonicum</i>USDA110

Soybean (Glycine max L.) plays an essential role in human nutrition as a protein source, and in plant nutrition as a N source. The rate of N fixation varies depending on the cultivars and compatibility between the inoculated Rhizobium strain and the host cultivar. Characterizing the nodulation regulatory (Rj) genes is necessary to determine the compatibility of cultivars and Rhizobium strains. Rj genes were previously identified based on inoculation tests and PCR analyses. The six cultivars Yezin-3, Yezin-7, Yezin-11, Shan Seine (Local), Madaya (Local), and Hinthada (Local) were identified as harboring the Rj4 gene. Two cultivars, Yezin-6 and Yezin-8, were classified as non-Rj-gene harboring. Two other cultivars, Yezin-9 and Yezin-10, were identified as Rj3- and Rj2Rj3-gene harboring, respectively. Ours is the first report on Rj3- and Rj2Rj3-gene harboring cultivars in Myanmar. We evaluated Myanmar soybean cultivars for symbiotic effectiveness, relying on the standard strain Bradyrhizobium japonicum USDA110. In our first experiment, the soybean cultivar Yezin-11 (Rj4) showed the highest N fixing potential. Based on their potential for fixing N and nodulation, the top six soybean cultivars were Yezin-11 (Rj4), Yezin-9 (Rj3), Yezin-6 (non-Rj), Yezin-8 (non-Rj), Yezin-3 (Rj4) and Yezin-10 (Rj2Rj3). These cultivars were selected for a second experiment, which revealed that the N fixation, nodulation, and plant growth of Yezin-11 (Rj4) *Corresponding author. A. Z. Htwe et al. 2800 were superior to the other cultivars. We conclude that Yezin-11 (Rj4) is the most efficient cultivar for nodulation and N fixation when inoculated with B. japonicum USDA110.

S100b protects IMR-32 cells against Ab(1-42) induced neurotoxicity via modulation of apoptotic genes expression

Amyloid beta (1-42) peptide is considered responsible for the formation of senile plaques that accumulate in the brain of patients with Alzheimer’s disease (AD). In the past years considerable attention has been focused on identifying new protective substances that prevent or almost retard the appearance of amyloid beta (1-42)-related neurotoxic effects. In this study, human neuroblastoma cells (IMR-32) was used as system model to evaluate the protective role of S100b, a neurotrophic factor and neuronal survival protein, that is highly expressed by reactive astrocytes in close vicinity of beta-amyloid deposits, against amyloid beta (1-42)-dependent toxicity. Our results show that at nanomolar concentrations, S100b protects cells against Aβmediated cytotoxicity, as assessed by MTS vitality test. The protective mechanism seems to be related to the effect on bcl-2 (an anti-apoptotic gene) expression, which is highly down-regulated by amyloid beta (1-42) treatment, while resulted more expressed in the presence of S100b. On the contrary, Bax, a proapoptotic gene, resulted down-regulated by the treatment with S100 compared with the results obtained in the presence of amyloid beta (1-42) peptide. However, at micromolar doses, S100b is toxic for IMR-32 cells and its toxicity adds to that of the Aβpeptide, suggesting that additional molecular mechanisms may be involved in theneurotoxic process.

Cloning and Expression Analysis of <i>RrRUP</i>2 Gene Related to Photomorphogenesis Biosynthesis in <i>Rosa rugosa</i>

Plants have evolved and perfected a series of light receptors to feel the light at different bands and regulate the expression, modification and interaction of related genes in plants through signal transduction. So far, many photoreceptors have been identified in plants, UVR8 has recently been identified as a receptor for UV-B light. This paper cloned a WD40 gene related to UVR8 protein subunit, named RrRUP2, based on the Rosa rugose transcriptome data, using Rosa rugose “Zi zhi” as experimental materials. The full length of cDNA of the gene was obtained by RT-PCR and RACE methods. The total length of this gene is 1173 bp, and it encodes 390 amino acids. After bioinformatics analysis, the molecular formula C3415H5659N1173O1434S313 was predicted;the relative molecular weight was 96129.27 Da;the theoretical isoelectric point PI value was 5.00;and its instability index was 47.06. The total average hydrophobic index was 0.750. In the secondary structure of RrRUP2 protein, there are 10 α-helix, 45 β-helix, 181 Random coil, and 154 Extended strand. Gene Bank Blast results showed that the amino acid sequence encoded by RrRUP2 was more than 90% homologous with the RUP2 protein of Rosa chinensis, Fragaria, Malus, Pyrus, Prunus, Juglans, Arabidopsis and Tobacco, so it can be inferred that the RrRUP2 gene is a WD repeat-containing protein. Regarding to fluorescence quantitative expression analysis of RrRUP2, we find its experssion pattern is corresponded with the accumulation of anthocyanins.

Expression of IGF-Ⅱ,p53,p21 and HBxAg in precancerous events of hepatocarcinogenesis induced by AFBI and/or HBV in tree shrews

INTRODUCTIONIn order to study the relationship between oncogeneexpression and HCC generation,we observed theprecancerous hepatic GGT loci,IGF-Ⅱ,p53 andp21 expression during hepatocarcinogenesis of treeshrew induced by hepatitis B virus (HBV) and/oraflatoxin B1 (AFB1).

Expression of hepatitis B virus genes in early embryonic cells originated from hamster ova and human spermatozoa transfected with the complete viral genome

Aim： To detect the expression of hepatitis B virus （HBV） genes （HB S and C genes） in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fertilization （IVF） technique. Methods： Human sperm-mediated HBV genes were delivered into zona-free hamster oocytes by the IVF method. Polymerase chain reaction （PCR） was used to detect HB S and pre-Core/Core （pre-C/C） coding genes both in one- and two-cell embryos. Reverse transcription-PCR （RT-PCR） analysis was used to study the expression of the two genes. Fluorescence in situ hybridization （FISH） analysis using the full-length HBV DNA as the hybridization probe was performed to confirm the integration of viral DNA in the host embryonic genome. Results： Both HB S and pre-C/C coding genes are present and transcribed in one- and two-cell embryos originated from hamster ova IVF with human spermatozoa carrying HBV DNA sequences. Conclusion： Sperm-mediated HBV genes are able to replicate and express themselves in early embryonic cells. These results provide direct evidence that HBV DNA could transmit vertically to the next generation via the male germ line.

Expression and significance of HBV genes and their antigens in human primary intrahepatic cholangiocarcinoma

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Sequence Comparison of Partial Cytochrome b Genes of Two Coilia species

Sequence variation of partial cytochrome b genes between two Coilia species, C. ectenes and C. mystus, was in- vestigated. Of the 402 nucleotides, twenty-seven (6.72%) are polymorphic and all are synonymous substitutions. At the third positions of genetic condon of cytochrome b gene, the two species show an extreme anti-G bias (<4%) and a pronounced bias towards A and C (>68%). There is no amino acid sequence divergence between the partial cytochrome b genes of the two species, indicating a close genetic relationship between them. The k-2p genetic distance of partial cytochrome b segment of the two species is 0.072, suggesting that the species were separated 3.6 Ma ago, in the middle Pliocene. Our result reveals that the cytochrome b gene is an appropriate marker for studies of population genetic structures and phylogeographic pat- terns of the two species.

Transactivating effect of complete S protein of hepatitis B virus and cloning of genes transactivated by complete S protein using suppression subtractive hybridization technique

AIM: To investigate the transactivating effect of complete S protein of hepatitis B virus (HBV) and to construct a subtractive cDNA library of genes transactivated by complete S protein of HBV by suppression subtractive hybridization (SSH) technique and to clone genes associated with its transactivation activity, and to pave the way for elucidating the pathogenesis of hepatitis B virus infection.METHODS: pcDNA3.1(-)-complete S containing full-length HBV S gene was constructed by insertion of HBV complete S gene into BarmH-I/Kpn I sites. HepG2 cells were cotransfected with pcDNA3.1(-)-complete S and pSV-lacZ.After 48 h, cells were collected and detected for the expression of β-galactosidase (β-gal). Suppression subtractive hybridization and bioinformatics techniques were used.The mRNA of HepG2 cells transfected with pcDNA3.1(-)-complete S and pcDNA3.1(-) empty vector was isolated,and detected for the expression of complete S protein by reverse transcription polymerase chain reaction (RT-PCR)method, and cDNA was synthesized. After digestion with restriction enzyme RcaI, cDNA fragments were obtained.Tester cDNA was then divided into two groups and ligated to the specific adaptors 1 and 2, respectively. After tester cDNA had been hybridized with driver cDNA twice and underwent nested PCR twice, amplified cDNA fragments were subcloned into pGEM-Teasy vectors to set up the subtractive library. Amplification of the library was carried out within E. coli strain DH5α. The cDNA was sequenced and analyzed in GenBank with BLAST search after polymerase chain reaction (PCR) amplification.RESULTS: The complete S mRNA could be detected by RT-PCR in HepG2 cells transfected with the pcDNA3.1(-)-complete S. The activity of β-gal in HepG2 cells transfected with the pcDNA3.1(-)-complete S was 6.9 times higher than that of control plasmid. The subtractive library of genes transactivated by HBV complete S protein was constructed successfully. The amplified library contains 86 positive clones. Colony PCR showed that 86 clones contained DNA inserts of 200-1 000 bp, respectively.Sequence analysis was performed in 35 clones randomly,and the full length sequences were obtained with bioinformatics method and searched for homologous DNA sequence from GenBank, altogether 33 coding sequences were obtained. These cDNA sequences might be target genes transactivated by complete S protein of HBV. Moreover, two unknown genes were discovered, full length coding sequences were obtained by bioinformatics techniques,one of them was named complete S transactivated protein 1 (CSTP1) and registered in GenBank (AY553877).CONCLUSION: The complete S gene of HBV has a transactivating effect on SV40 early promoter. A subtractive cDNA library of genes transactivated by HBV complete S protein using SSH technique has been constructed successfully. The obtained sequences may be target genes transactivated by HBV complete S protein among which some genes coding proteins are involved in cell cycle regulation, metabolism, immunity, signal transduction, cell apoptosis and formation mechanism of hepatic carcinoma.

Characterization and expression analysis of genes encoding Taxol biosynthetic enzymes in Taxus spp.

Taxol(Paclitaxel),an important anticancer drug,is derived at very low yields from Taxus(yew)species that grow very slowly.In the present study,thirteen genes that encode enzymes involved in Taxol biosynthesis in Taxus spp.were analyzed with bioinformatics methods,and their expression levels in different tissues and after cold and hormone treatments were also analyzed.The results indicated that many cis-elements related to abiotic stresses and hormones were found in the promoter sequences of the 8 genes involved in Taxol biosynthesis.Moreover,the 13 enzymes encoded by the target genes were located in different organelles and had many phosphorylation sites in the response proteins.The 13 genes were expressed highly either in roots or in stems,with lower transcripts in needles,and they were highly expressed after treatment with cold,gibberellin,methyl jasmonate or coronatine,consistent with predictions based on the bioinformatics analysis.These results suggest that the factors such as hormones and abiotic stresses stimulate taxane biosynthesis in yews,providing an important way to sustainably generate taxanes from yew trees or their cell cultures to improve Taxol yields.

Identification of Light-Harvesting Chlorophyll a/b-Binding Protein Genes of Zostera marina L.and Their Expression Under Different Environmental Conditions

Photosynthesis includes the collection of light and the transfer of solar energy using light-harvesting chlorophyll a/b-binding(LHC) proteins.In high plants,the LHC gene family includes LHCA and LHCB sub-families,which encode proteins constituting the light-harvesting complex of photosystems I and II.Zostera marina L.is a monocotyledonous angiosperm and inhabits submerged marine environments rather than land environments.We characterized the Lhca and Lhcb gene families of Z.marina from the expressed sequence tags(EST) database.In total,13 unigenes were annotated as Zm Lhc,6 in Lhca family and 7 in Zm Lhcb family.Zm LHCA and Zm LHCB contained the conservative LHC motifs and amino acid residues binding chlorophyll.The average similarity among mature Zm LHCA and Zm LHCB was 48.91% and 48.66%,respectively,which indicated a high degree of divergence within Zm LHChc gene family.The reconstructed phylogenetic tree showed that the tree topology and phylogenetic relationship were similar to those reported in other high plants,suggesting that the Lhc genes were highly conservative and the classification of Zm Lhc genes was consistent with the evolutionary position of Z.marina.Real-time reverse transcription(RT) PCR analysis showed that different members of Zm Lhca and Zm Lhcb responded to a stress in different expression patterns.Salinity,temperature,light intensity and light quality may affect the expression of most Zm Lhca and Zm Lhcb genes.Inorganic carbon concentration and acidity had no obvious effect on Zm Lhca and Zm Lhcb gene expression,except for Zm Lhca6.

The benzo(a) pyrene-induced mRNA expression of aromatic hydrocarbon receptor and cytochrome P4501A1 genes in rat liver

Objective To study the benzo(a)pyrene(B[a]P)-induced mRNA expression of aromatic hydrocarbon receptor(AHR)and cytochrome P4501A1(CYP1A1)genes in rat liver.Methods Rats were injected intraperitoneally with 5,10 and 15mg/kg of B[a]P.The total RNAs were extracted from rat livers by RNA purification kit,and the mRNA expression of AHR and CYP1A1 genes was determined by reverse transcription polymerase chain reaction(RT-PCR).β-actin was used as the internal control.The mRNA expression of both AHR and CYP1A1 genes was measured at indicated time points(24,48 and 72h)after B[a]P treatment at three different concentrations(5,10 and 15mg/kg).Results The mRNA expression of AHR gene increased in a time-dependent manner at the concentration of 10mg/kg but not at 5 and 15mg/kg of B[a]P.The mRNA expression of CYP1A1 gene differed significantly at 48h and 24h in rat livers treated with 10 and 15mg/kg dosage of B[a]P.The mRNA expression of AHR and CYP1A1 genes increased with B[a]P treatment in a concentration-dependent manner.The time-dependent increase in mRNA expression was shown by AHR but not by CYP1A1 gene with B[a]P(10mg/kg)treatment.Conclusion This study demonstrates that toxic B[a]P increases the mRNA expression of both AHR and CYP1A1 genes in vivo,suggesting that B[a]P may play a role in cancer genesis by this way.

Adenovirus-expressed preS2 antibody inhibits hepatitis B virus infection and hepatic carcinogenesis

AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light and heavy chains of the HBV preS2Ab gene,Ad315-preS2Ab,was constructed.Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expres-sion levels in vitro.Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells.ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells.The inhibitory effect of preS2Ab against hepatic carcinogen-esis was studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice.RESULTS:The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells,with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell.The expressed preS2Abs could recog-nize liver cells from HBV transgenic mice.ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV pa-tients than parental L02 cells expressing no preS2Ab.HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vec-tor or untreated mice.Additionally,the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase.CONCLUSION:Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells,and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.

Ephrin-B reverse signaling induces expression of wound healing associated genes in IEC-6 intestinal epithelial cells

AIM: Eph receptors and ephrin ligands play a pivotal role in development and tissue maintenance. Since previous data have indicated an involvement of ephrin-B2 in epithelial healing, we investigated the gene expression and downstream signaling pathways induced by ephrin-B mediated cell-cell signaling in intestinal epithelial cells.METHODS: Upon stimulation of ephrin-B pathways in IFC-6 cells with recombinant rat EphB1-Fc, gene expression was analyzed by Affymetrix(R) rat genome 230 high density arrays at different time points. Differentially expressed genes were confirmed by real-time RT-PCR. In addition, MAP kinase pathways and focal adhesion kinase (FAK) activation downstream of ephrin-B were investigated by immunoblotting and fluorescence microscopy.RESULTS: Stimulation of the ephrin-B reverse signaling pathway in IEC-6 cells induces predominant expression of genes known to be involved into wound healing/cell migration, antiapoptotic pathways, host defense and inflammation. Cox-2, c-Fos, Egr-1, Egr-2, and MCP-1 were found among the most significantly regulated genes.Furthermore, we show that the expression of repairrelated genes is also accompanied by activation of the ERK1/2 MAP kinase pathway and FAK, two key regulators of epithelial restitution.CONCLUSION: Stimulation of the ephrin-B reverse signaling pathway induces a phenotype characterized by upregulation of repair-related genes, which may partially be mediated by ERK1/2 pathways.