Identification of a Regulatory Single Nucleotide Polymorphism in the Adiponectin (APM1) Gene Associated with Type 2 Diabetes in Han Nationality

Objective To identify the genetic defects of the the adiponectin （APM1） gene that contribute to the development of type 2 diabetes （T2DM） and determine the functional single nucleotide polymorphisms （SNPs） in the APMI gene associated with T2DM in Han nationality. Methods The APMI gene 5＇-UTR was screened by direct sequencing to identify common polymorphisms. Identified SNPs were genotyped in 585 nondiabetic controls, 278 subjects with impaired glucose intolerance （IGT） and 212 patients with T2DM. The functions of SNPs in the regulatory region were assessed by reporter gene assay. Possible association between SNPs and plasma APMI levels or metabolic parameters was statistically asses,sed. Results Three SNPs were identified in the APMI gene 5＇-UTR. A case-control study revealed that SNP -11377 G/C had significant differences in allele frequencies between T2DM patients and nondiabetic controls （G 0.314/C 0.686 vs. G 0.265/C 0.735, P=0.03）. Haplotype analysis of three SNPs in the APM1 gene showed that no significant association of haplotypes with T2DM. IGT was detected in the present study. Reporter gene assay showed that SNP did not influence the transcription efficiency in the 3T3-LI cell line. Conclusion SNP - 11377 G/C in the proximal promoter region of the APM 1 gene contributes to the development of T2DM in Han nationality but may not be a functional SNP in the APM1 gene.

Association of Gghrelin Polymorphisms with Metabolic Syndrome in Han Nationality Chinese

Objective To investigate the association of ghrelin gene polymorphisms with metabolic syndrome in Han Nationality Chinese. Methods A total of 240 patients with metabolic syndrome and 427 adults aged above forty years were recruited. Genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism analysis. Results The allelic frequency of the Leu72Met polymorphism was 17.3% in the patient group and 11.9% in the control group （x^2=7.36, P=0.007）. Metabolic syndrome was more prevalent among carriers of the Met72 variant （43.8 vs 33.1%, age- and sex-adjusted odds ratio=1.57, P=0.01）. No Arg51Gln variants were found in our study subjects. Conclusion Rather than being associated with its individual components, Leu72Met polymorphism is associated with metabolic syndrome in the Han Nationality Chinese. Arg51Gln polymorphism is rare in the Han Nationality Chinese.

DTNBP1 Gene Is Associated with Some Symptom Factors of Schizophrenia in Chinese Han Nationality

Objective To study the association of DTNBP1 gene with some symptom factors of schizophrenia.Methods A total of 285 unrelated schizophrenic individuals were recruited from December 2004 to January 2009 for genetic analysis,and their symptom factors were assessed based on the Positive and Negative Syndrome Scale(PANSS).The quantitative trait test was performed by the UNPHASED program(version 3.0.12) to investigate the association between scored positive and negative symptoms and the single nucleotide polymorphisms(SNPs) in DTNBP1 gene.Results The quantitative trait test showed allelic association of rs909706 with the excitement symptom of schizophrenia(P<0.05,adjusted by 10 000 permutations),while the genotype C/G of rs2619539 with a negative symptom,lack of spontaneity and flow of conversation(P<0.05,adjusted by 10 000 permutations).Conclusion DTNBP1 variations are possibly associated with some symptoms of schizophrenia,which could partly explain the relationship between the susceptibility gene DTNBP1 and that disease.

Effects of cyclooxygenase-2 on human esophageal squamous cell carcinoma

AIM:To study the relationship between the cyclooxy-genase(COX)-2 gene and the proliferation and apopto-sis of esophageal squamous carcinoma EC109 cells.METHODS:The techniques of RNA interference(RNAi)and cell transfection,as well as the levels of oncogenic-ity in nude mice,were used to study the role of COX-2 in the esophageal squamous carcinoma cell(ESCC)line EC109.Following RNAi and transfection,Western blot-ting analysis was used to determine the expression of the COX-2 protein.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)reduction assay was used to evaluate cell growth,and flow cytometry was used to detect cell apoptosis.RESULTS:Western blotting analysis demonstrated that COX-2 expression was significantly reduced in EC109 cells treated with COX-2-specif ic short interfering RNA(siRNA)but was increased in EC109 cells transfected with COX-2.Furthermore,COX-2 siRNA treatment in-hibited cell proliferation(P < 0.01)and induced apop-tosis in EC109 cells,as determined by an MTT assay and by flow cytometry,respectively.In contrast,trans-fected COX-2 led to increased cell proliferation(P < 0.05)and decreased apoptosis in EC109 cells.In addition,combination treatment of cells with COX-2 siRNA and aspirin had a synergistic effect(P < 0.01).For experi-ments measuring tumorigenicity,xenograft tumors of a greater volume and weight were found in the COX-2 group compared with other groups(P < 0.05).A large dose of aspirin inhibited tumor growth in nude mice ef-fectively(P < 0.05),and the rate of tumor suppression was 51.8% in the high-dose aspirin group.CONCLUSION:COX-2 plays a very critical role in ESCC carcinogenesis,and COX-2 siRNA combined with aspirin has the potential to be an anticancer therapy for the treatment of ESCC.

PTEN and PDCD4 are Bona Fide Targets of microRNA-21 in Human Cholangiocarcinoma

Objective To investigate the expression profile of microRNA-21 in human cholangiocarcinoma tis- sues and to validate its bona fide targets in human cholangiocarcinoma cells. Methods The expression profile of microRNA-21 in human cholangiocarcinoma tissues and cholan- giocarcinoma cell line, QBC939, was evaluated by using real-time PCR analysis. The bona fide targets of microRNA-21 were analyzed and confirmed by dual luciferase reporter gene assay and western blot, respec- tively. The expressional correlation of microRNA-21 and its targets was probed in human cholangiocarci- noma tissues by using real-time PCR, locked nucleic acid in situ hybridization （LNA-ISH）, and immunohis- tochemistry analysis. Results Real-time PCR analysis revealed that microRNA-21 expression depicted a significant up-regulation in human cholangiocarcinoma tissues about 5.6-fold as compared to the matched normal bileduct tissues （P〈0.05）. The dual luciferase reporter gene assay revealed endogenous microRNA-21 in cholan- giocarcinoma cell line, QBC939, inhibited the luciferase reporter activities of wild-type PTEN （P〈0.01） and PDCD4 （P〈0.05） and had no this effect on mutated PTEN and PDCD4. Moreover, loss of microRNA-21 function led to a significant increase of PTEN and PDCD4 protein levels in QBC939 cells. Elevated microRNA-21 levels were accompanied by marked reductions of PTEN and PDCD4 expression in the same cholangiocarcinoma tissue. Conclusion microRNA-21 expression is up PDCD4 are direct effectors of microRNA-21. regulated in human cholangiocarcinoma and PTEN,

Multiple Risk Factor Clustering and Risk of Hypertension in the Mongolian Ethnic Population of China

Objective To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension （EH） and the accumulation of risk factors influences the blood pressure level in normotensives. Methods On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity （243 hypertensives and 258 normotensives） who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion （I/D） polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. Results Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH （P〈0.05）. The odds ratios （OR） for the number of risk factors were 2.39 （95%CI： 0.98-6.74） for one risk factor, 5.03 （95%CI： 2.06-14.18） for two, and 6.09 （95%CI： 1.85-22.38） for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors （P〉0.05）. Conclusion Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.

A Second Protein Marker of Caveolae:Caveolin-2

Caveolin-2,a protein about 20 kD,is a major component of the inner surface of caveolae,small invaginations of the plasma membrane.Similar with caveolin-1 and caveolin-3,it serves as a protein marker of caveolae.Caveolin-1 and-2 are located next to each other at 7q31.1 on human chromosome,the proteins encoded are co-localized and form a stable hetero-oligomeric complex,distributing similarly in tissue and cultured cells.Caveolin-3 is located on different chromosomes but confirmed to interact with caveolin-2.Caveolin-2 is similar to caveolin-1 in many respects but differs from the latter in functional domains,especially in G-protein binding domain and caveolin scaffolding domain.The mRNAs of both caveolin-1 and caveolin-2 are most abundantly expressed in white adipose tissue and are induced during differentiation of 3T3-L1 cells to adipocytes.Caveolin-2-deficinet mice demonstrate clear pulmonary defects,with little or no change in caveolin-1 expression and caveolae formation,suggesting that caveolin-2 plays a selective role in lung functions.Caveolin-2 is also involved in lipid metabolism and human cancers.

Pancreatic metastasis of renal cell carcinoma

BACKGROUND： Renal cell carcinoma （RCC） is a common cancer, but pancreatic metastasis of RCC is unusual. Because of the rarity and peculiarity, pancreatic lesions from RCC metastasis were described mostly in case reports which highlight the importance of a systematic analysis of this clinical condition. DATA SOURCES： Data of 7 patients with pancreatic metastasis of RCC treated in the Peking Union Medical College Hospital were extracted and 193 similar patients reported in the past 10 years from the literature were analyzed. Epidemiological, pathological and follow-up information were investigated. Po- tential prognostic factors were compared with corresponding data reported 10 years ago. RESULTS： Multivariate Cox regression showed that asymp- tomatic metastasis and surgical procedure were independent factors associated with better survival. Compared with the data reported 10 years ago, follow-up of RCC patients has been emphasized in recent years, and atypical surgery is frequently used since it has similar effect as typical surgery on tumor resection while it is able to preserve more pancreatic function. CONCLUSION： Surgical treatment should be an option as long as the pancreatic metastasis of RCC is resectable.

Regulation of Acyl-coenzyme A:Cholesterol Acyltransferase 2 Expression by Saturated Fatty Acids

Objective To verify the regulation of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT 2), which is associated with cholesterol metabolism, by saturated fatty acids (SFAs). Methods Palmitic acid (PA), the most abundant saturated fatty acid in plasma, and oleic acid (OA), a widely distributed unsaturated fatty acid, were used to treat hepatic cells HepG2, HuH7, and mouse primary hepatocytes. In addition, PA at different concentrations and PA treatment at different durations were applied in HepG2 cells. In in vivo experiment, three-month male C57/BL6 mice were fed with control diet and SFA diet containing hydrogenated coconut oil rich of SFAs. The mRNA level of ACAT2 in those hepatic cells and the mouse livers was detected with real-time polymerase chain reaction (PCR). Results In the three types of hepatic cells treated with PA, that SFA induced significant increase of ACAT2 expression (P<0.01), whereas treatment with OA showed no significant effect. That effect of PA was noticed gradually rising along with the increase of PA concentration and the extension of PA treatment duration (both P<0.05). SFA diet feeding in mice resulted in a short-term and transient increase of ACAT2 expression in vivo, with a peak level appearing in the mice fed with SFA diet for two days (P<0.05). Conclusion SFA may regulate ACAT2 expression in human and mouse hepatic cells and in mouse livers.

Gene Expression Profile of Human Skeletal Muscle and Adipose Tissue of Chinese Han Patients with Type 2 Diabetes Mellitus

Objective To study the differential patterns of gene expression in skeletal muscle and adipose tissue between type 2 diabetes mellitus （T2DM） patients and healthy subjects using DNA microarray analysis, Methods T2DM patiens were divided into female group, young male group and old male group. DNA microarray analysis and quantitative real-time PCR were carried out to anaIyze the relation between gene expressions and T2DM. Results The mRNA expression of 298, 578, and 350 genes was changed in the skeletal muscle of diabetes mellitus patients compared with control subjects. The 1320, 1143, and 2847 genes were modified in adipose tissue of the three groups. Among the genes surveyed, the change of 25 and 39 gene transcripts in skeletal muscle and adipose tissue was ≥2 folds, These differentially expressed genes were classified into 15 categories according to their functions. Conclusion New genes are found and T2DM can be prevented or cured.

Antibody gene therapy: an attractive approach for the treatment of cancers and other chronic diseases

Monoclonal (mAb ) 成功地被用于长期的疾病的治疗，例如癌症，发炎和有免疫力的疾病。与在抗体工程的技术进展，当有减少的 immunogenicity 的高亲密关系治疗学在聚光灯下面变得，小重组体抗体的开发碎裂。设计重组体抗体碎片的一种流行格式是单个链的改正变量(scFv ) 分子，父母抗体的 VH 和 VL 区域被一个多肽连接器一起在连接。scFv 碎片保留目标特性和未经触动的抗体，和罐头的抗原绑定亲密关系被在房间从单个 cDNA 表示 VH 和 VL 区域的宫外的联盟者遗传上在大数量设计并且生产。由于它的更小的尺寸， scFv 分子表演在肿瘤穿入改进了 pharmacokinetics 并且被主人免疫系统更好容忍。

NF-E2:a Novel Regulator of Alpha-hemoglobin Stabilizing Protein Gene Expression

Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45. Results We found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45. Conclusion NF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.

Nectin-like Molecule 1 Inhibits the Migration and Invasion of U251 Glioma Cells by Regulating the Expression of An Extracellular Matrix Protein Osteopontin

Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.

A switch from hBrm to Brgl at IFNy-activated sequences mediates the activation of human genes

The SWI/SNF chromatin-remodeling complexes utilize energy from ATP hydrolysis to reposition nucleosomes and regulate the expression of human genes. Here, we studied the roles of human Brahma （hBrm） and Brahma-related gene 1 （Brgl）, the ATPase subunits of the SWI/SNF complexes, in regulating human genes. Our results indicate that both hBrm and Brgl interact with Signal transducer and activator of transcription （Stat） 1 in vitro. However, Statl in its native form only recruits hBrm to IFNy-activated sequences （GAS） of individual genes; by contrast, in a stress- induced phosphorylated form, Statl mainly binds to Brgl. Under basal conditions, hBrm is recruited by native Statl to the GAS and exists in a mSin3/HDAC co-repressor complex on the hsp90a gene, which shows a compact chromatin structure. Upon heat-shock, hBrm is acetylated by p300 and dissociates from the co-repressor complex, which the phosphorylated St^tl is increased, and binds and recruits Brgl to the GAS, leading to elevated induction of the gene. This hBrm/Brgl switch also occurs at the GAS of all of the three examined immune genes in heat-shocked cells; how- ever, this switch only occurs in specific cell types upon exposure to IFNy. Regardless of the stimulus, the hBrm/Brgl switch at the GAS elicits an increase in gene activity. Our data are consistent with the hypothesis that the hBrm/Brgl switch is an indicator of the responsiveness of a gene to heat-shock or IFNy stimulation and may represent an ＂on-off switch＂ of gene expression in vivo.

Epigenetic Repression of SATB1 by Polycomb Group Protein EZH2 in Epithelial Cells

Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.

Role of Acetylated p53 in Regulating the Expression of map2 in Retinoic Acid-induced P19 Cells

Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods Neuronal differentiation of P19 cells was initiated with 4-day RA treatment.Immunofluorescence,real-time reverse transcription-polymerase chain reaction(RT-PCR) assay,and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells.Real-time PCR-based chromatin immunoprecipitation assay(ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter.Results The expression of MAP2 was markedly increased in RA-induced P19 cells.The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment,compared with the cells without RA treatment(control).p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity.p300/CBP associated factor(PCAF) was found induced in RA-treated cells and enriched in the nucleus,which might contribute to the acetylation of p53 in the regulation of map2 gene.Conclusions Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells.PCAF is possibly involved in this process by mediating the acetylation of p53.

Association of Angiotensin Converting Enzyme Gene I/D Polymorphism With Type 2 Diabetes Mellitus

Objective To investigate the association of angiotensin converting enzyme （ACE） gene insertion/deletion （I/D） polymorphism with type 2 diabetes mellitus （T2DM）. Methods Two hundred and nine patients with T2DM diagnosed based on the criteria for diabetes mellitus in 1999 by WHO and 221 controls were recruited from general population of Dongcheng District in Beijing. All subjects were genotyped for the I/D polymorphism of ACE gene by PCR-fragment length polymorphism （FLP） assay. Blood pressure, levels of plasma glucose, lipids and serum insulin were determined. Body mass index （BMI）, waist-trip ratio （WHR） and homeostasis model assessment-insulin resistance index （HOMA-IR） were calculated. Results The genotype frequencies for ACE genes DD, ID, and II were 19.1%, 42.1%, and 38.8% in patients, respectively, and 9.6%, 49.4%, and 41.0% in controls, respectively. The ACE DD genotype frequency was significantly higher in patients than in controls （χ^2=7.61, P=0.022）. Multivariate logistic regression analysis showed that the ACE DD genotype was a risk factor for T2DM, with the OR of 2.35 （95% CI 1.17-4.71） adjusted for age, sex, BMI, WHR, blood pressure, and serum cholesterol levels. Conclusion The ACE DD genotype is associated with the increased susceptibility to type 2 diabetes mellitus.

Up-regulation of Fas Ligand Expression by Sirtuin 1 in both Flow-restricted Vessels and Serum-stimulated Vascular Smooth Muscle Cells

Objective To study the role of sirtuin 1 （SIRT1） in Fas ligand （FasL） expression regulation during vascular lesion formation and to elucidate the potential mechanisms. Methods SIRT1 and FasL protein levels were detected by Western blotting in either mouse arteries extract or the whole rat aortic vascular smooth muscle cell （VSMC） lysate. Smooth muscle cell （SMC）-specific human SIRT1 transgenic （Tg） C57BL/6 mice and their littermate wild-type （WT） controls underwent complete carotid artery ligation （ligation groups） or the ligation-excluded operation （sham groups）. The carotid arteries were collected 1 day after operation. Reverse transcription-polymerase chain reaction was performed to detect the mRNA levels of SIRT1 and FasL. Luciferase reporter assays were performed to detect the effect of WT-SIRT1, a dominant-negative form of SIRT1 （SIRT1H363Y）, and GATA-6 on the promoter activity of FasL. Flow cytometry assay was applied to measure the hypodiploid DNA content of VSMC so as to monitor cellular apoptosis. Results SIRTI was expressed in both rat aortic VSMCs and mouse arteries. Forced SIRT1 expression increased FasL expression both in injured mouse carotid arteries 1 day after ligation （P〈0.001） and VSMCs treated with serum （P〈0.05 at the transcriptional level, P〈0.001 at the protein level）. No notable apoptosis was observed. Furthermore, transcription factor GATA-6 increased the promoter activity of FasL （P〈0.001）. The induction of FasL promoter activity by GATA-6 was enhanced by WT-SIRT1 （P〈0.001）, while SIRT1H363Y significantly relieved the enhancing effect of WT-SIRT1 on GATA-6 （P〈0.001）. Conclusions Overexpression of SIRT1 up-regulates FasL expression in both flow-restricted mouse carotid arteries and serum-stimulated VSMCs. The transcription factor GATA-6 participates in the transcriptional regulation of FasL expression by SIRT 1.

Establishment of Cell Free Conversion System With Biotin-labelled Recombinant PrP^(sen) Expressed in E.coli

Objective To report a protocol using biotin-labelled PrP protein in cell free conversion assay instead of isotope. Methods A hamster PrP protein （HaPrP） was expressed in E. coli and purified with HIS-tag affinity chromatograph. After being labelled with biotin, HaPrP was mixed with PrP^sen preparation from scrapie strain 263K. Results Protease-resistant bands were detected after four-day incubation. Conclusion The new conversion model provides a reliable, easily handling, and environment-friendly method for studies of prion and transmissible spongiform encephalopathies.

Screening of Substrates of Protein Arginine Methyltransferase 1 in Glioma

Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.