Clinical feature difference between juvenile amyotrophic lateral sclerosis with SPTLC1 and FUS mutations / 中华医学杂志(英文版)

BACKGROUND@#Juvenile amyotrophic lateral sclerosis (JALS) is an uncommon form of amyotrophic lateral sclerosis whose age at onset (AAO) is defined as prior to 25 years. FUS mutations are the most common cause of JALS. SPTLC1 was recently identified as a disease-causative gene for JALS, which has rarely been reported in Asian populations. Little is known regarding the difference in clinical features between JALS patients carrying FUS and SPTLC1 mutations. This study aimed to screen mutations in JALS patients and to compare the clinical features between JALS patients with FUS and SPTLC1 mutations.@*METHODS@#Sixteen JALS patients were enrolled, including three newly recruited patients between July 2015 and August 2018 from the Second Affiliated Hospital, Zhejiang University School of Medicine. Mutations were screened by whole-exome sequencing. In addition, clinical features such as AAO, onset site and disease duration were extracted and compared between JALS patients carrying FUS and SPTLC1 mutations through a literature review.@*RESULTS@#A novel and de novo SPTLC1 mutation (c.58G>A, p.A20T) was identified in a sporadic patient. Among 16 JALS patients, 7/16 carried FUS mutations and 5/16 carried respective SPTLC1 , SETX , NEFH , DCTN1 , and TARDBP mutations. Compared with FUS mutation patients, those with SPTLC1 mutations had an earlier AAO (7.9 ± 4.6 years vs. 18.1 ± 3.9 years, P  < 0.01), much longer disease duration (512.0 [416.7-607.3] months vs. 33.4 [21.6-45.1] months, P  < 0.01), and no onset of bulbar.@*CONCLUSION@#Our findings expand the genetic and phenotypic spectrum of JALS and help to better understand the genotype-phenotype correlation of JALS.

m7G-lncRNAs are potential biomarkers for prognosis and tumor microenvironment in patients with colon cancer / 南方医科大学学报

OBJECTIVE@#To assess the value of m7G-lncRNAs in predicting the prognosis and microenvironment of colorectal cancer (CRC).@*METHODS@#We screened m7G-lncRNAs from TCGA to construct an m7G-lncRNAs risk model using multivariate Cox analysis, which was validated using ROC and C-index curves. Calibration and nomogram were used to predict the prognosis of CRC patients. Point-bar charts and K-M survival curves were used to assess the correlation of risk scores with the patients' clinical staging and prognosis. CIBERSORT and ESTIMATE were used to explore the association between the tumor microenvironment and immune cell infiltration in patients in high and low risk groups and the correlation of risk scores with microsatellite instability, stem cell index and immune checkpoint expression. A protein-protein interaction network was constructed, and the key targets regulated by m7G-lncRNAs were identified and validated in paired samples of CRC and adjacent tissues by immunoblotting.@*RESULTS@#We identified a total of 1722 m7G-lncRNAs from TCGA database, from which 12 lncRNAs were screened to construct the risk model. The AUCs of the risk model for predicting survival outcomes at 1, 3 and 5 years were 0.727, 0.747 and 0.794, respectively. The AUC of the nomogram for predicting prognosis was 0.794, and the predicted results were consistent with actual survival outcomes of the patients. The patients in the high-risk group showed more advanced tumor stages and a greater likelihood of high microsatellite instability than those in the low-risk group (P < 0.05). The tumor stemness index was negatively correlated with the risk score (r=-0.19; P=7.3e-05). Patients in the high-risk group had higher stromal cell scores (P=0.0028) and higher total scores (P=0.007) with lowered expressions of activated mast cells (r=-0.11; P=0.045) and resting CD4+ T cells (r=-0.14; P=0.01) and increased expressions of most immune checkpoints (P < 0.05). ATXN2 (P= 0.006) and G3BP1 (P=0.007) were identified as the key targets regulated by m7G-lncRNAs, and their expressions were both higher in CRC than in adjacent tissues.@*CONCLUSION@#The risk model based on 12 m7G-lncRNAs has important prognostic value for CRC and can reflect the microenvironment and the efficacy of immunotherapy in the patients.

Infección de Aedes albopictus (Skuse, 1894) con el genotipo asiático-americano del virus del dengue serotipo 2 en Medellín y su posible papel como vector del dengue en Colombia / Aedes albopictus (Skuse, 1894) infected with the American-Asian genotype of dengue type 2 virus in Medellín suggests its possible role as vector of dengue fever in Colombia

Resumen Introducción. Aedes aegypti y Ae. albopictus son reconocidos vectores de arbovirus como los del dengue, la fiebre amarilla, el chikungunya y el Zika, en regiones tropicales y subtropicales del mundo. En Colombia, la distribución geográfica de Ae. albopictus ha sufrido un incremento y hoy incluye ciudades como Cali y Medellín. Hasta ahora, sin embargo, no se ha recabado información concluyente sobre su infección viral y su capacidad de transmisión a los humanos. Objetivo. Determinar la infección natural por dengue en ejemplares de Ae. albopictus recolectados en un área urbana de Medellín. Materiales y métodos. Se recolectaron individuos de Ae. albopictus en el campus de la Universidad Nacional de Colombia, sede Medellín. Se confirmó su clasificación taxonómica mediante el análisis del gen citocromo oxidasa I (COI), y se extrajo el ARN total para la identificación del virus del dengue y de los respectivos serotipos. La presencia del genotipo DENV se infirió mediante el análisis del gen NS3. Resultados. El análisis del COI corroboró el estatus taxonómico de Ae. albopictus. Uno de los mosquitos procesados fue positivo para DENV-2 y el análisis del NS3 mostró una gran similitud con el genotipo asiático-americano. Conclusión. Se reporta la infección con DENV-2 en Ae. albopictus en Medellín, Colombia. La presencia del genotipo asiático-americano en una zona urbana sugiere su posible circulación entre humanos y en Ae. albopictus, lo cual alerta sobre su eventual papel en la transmisión del DENV-2, y sobre la necesidad de incluir esta especie en la vigilancia entomológica en Colombia.

Abstract Introduction: Aedes aegypti and Ae. albopictus are recognized vectors of dengue, yellow fever, chikungunya and Zika arboviruses in several countries worldwide. In Colombia, Ae. albopictus geographical distribution has increased to include highly populated cities such as Cali and Medellín. Although this species has been frequently found in urban and semi-urban zones in the country, its role as vector of the dengue fever is poorly known. Objective: To identify the presence of Ae. albopictus specimens naturally infected with dengue virus collected in Medellín. Materials and methods: Insects were collected in the Universidad Nacional de Colombia campus in Medellín. Individuals were classified as Ae. albopictus and confirmed by DNA barcode region analysis. Mosquitoes were processed for dengue virus identification, and a fragment of the NS3 gen was sequenced and compared with DENV-2 genotypes reported in the literature. Results: Sequence analysis of COI indicated Ae. albopictus individuals were similar to those recently reported in Colombia, and genetically close to those from other regions worldwide. Among the pools tested one was positive for DENV-2, and the NS3 analysis indicated it belonged to the Asian-American clade. Conclusion: We report the presence Ae. albopictus naturally infected with the Asian-American genotype of DENV-2 in Colombia. The presence of Ae. albopictus specimens carrying the most common genotype infecting humans in a highly populated city such as Medellín indicates its potential role as dengue vector in Colombia and highlights the relevance of including it in current vector surveillance strategies.

Anticuerpos policlonales contra la proteína recombinante NS3 del virus del dengue / Polyclonal antibodies against recombinant dengue virus NS3 protein

Resumen Introducción: El dengue es una enfermedad causada por uno de los cuatro serotipos del virus del dengue (DENV) y es endémica en, aproximadamente, 130 países. Su incidencia ha aumentado notablemente en las últimas décadas, así como la frecuencia y la magnitud de los brotes. A pesar de los esfuerzos, no existen tratamientos profilácticos ni terapéuticos contra la enfermedad y, en ese contexto, el estudio de los procesos que gobiernan el ciclo de infección del DENV es esencial para desarrollar vacunas o terapias antivirales. Una de las moléculas del DENV más prometedoras es la proteína no estructural 3 (NS3), la cual es indispensable para la replicación viral y es uno de los principales blancos inmunológicos durante la infección. Objetivo: Producir anticuerpos policlonales para contribuir a los futuros estudios sobre las interacciones entre la proteína NS3 y otras proteínas celulares. Materiales y métodos: Se expresaron dos proteínas recombinantes del dominio helicasa de NS3 del DENV de serotipo 2, las cuales se emplearon para inmunizar ratas y producir anticuerpos policlonales. Resultados: Los anticuerpos producidos fueron útiles en ensayos de Western blot e inmunofluorescencia y se reportó por primera vez un anticuerpo policlonal anti-NS3 que permitió la inmunoprecipitación de la proteína viral y la detecta con Western blot sin necesidad de inducir sobreexpresión de NS3 o de usar extractos de células marcados metabólicamente con radioisótopos. Conclusión: Las proteínas recombinantes expresadas y los anticuerpos producidos constituyen herramientas valiosas para estudiar procesos infecciosos del DENV que involucren a la proteína NS3 y evaluar pruebas dirigidas a interferir las funciones de esta proteína.

Abstract Introduction: Dengue is a disease caused by one of four serotypes of the dengue virus (DENV) and is endemic in approximately 130 countries. The incidence of dengue has increased dramatically in recent decades, as well as the frequency and magnitude of outbreaks. Despite all efforts, there are no prophylactic or therapeutic treatments for the disease. Accordingly, research on the processes governing the DENV infection cycle is essential to develop vaccines or antiviral therapies. One of the most attractive DENV molecules to investigate is nonstructural protein 3 (NS3), which is essential for viral replication and a major immune target for infection. Objective: To produce antibodies to support future studies on NS3 and its cellular interactions with other proteins. Materials and methods: Two recombinant proteins of the helicase domain of DENV NS3 serotype 2 were expressed, and used to immunize mice and produce polyclonal antibodies. Results: The antibodies produced were useful in Western blot and immunofluorescence tests. We report an NS3 antibody that immunoprecipitates the viral protein and detects it in Western blot with no need to over-express it or use cell extracts with metabolic radiolabeling.

Structural basis of Zika virus helicase in recognizing its substrates

The recent explosive outbreak of Zika virus (ZIKV) infection has been reported in South and Central America and the Caribbean. Neonatal microcephaly associated with ZIKV infection has already caused a public health emergency of international concern. No specific vaccines or drugs are currently available to treat ZIKV infection. The ZIKV helicase, which plays a pivotal role in viral RNA replication, is an attractive target for therapy. We determined the crystal structures of ZIKV helicase-ATP-Mn(2+) and ZIKV helicase-RNA. This is the first structure of any flavivirus helicase bound to ATP. Comparisons with related flavivirus helicases have shown that although the critical P-loop in the active site has variable conformations among different species, it adopts an identical mode to recognize ATP/Mn(2+). The structure of ZIKV helicase-RNA has revealed that upon RNA binding, rotations of the motor domains can cause significant conformational changes. Strikingly, although ZIKV and dengue virus (DENV) apo-helicases share conserved residues for RNA binding, their different manners of motor domain rotations result in distinct individual modes for RNA recognition. It suggests that flavivirus helicases could have evolved a conserved engine to convert chemical energy from nucleoside triphosphate to mechanical energy for RNA unwinding, but different motor domain rotations result in variable RNA recognition modes to adapt to individual viral replication.

DEAD/DExH-Box RNA Helicases in Selected Human Parasites

DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.

Human Rhinovirus-induced Proinflammatory Cytokine and Interferon-beta Responses in Nasal Epithelial Cells From Chronic Rhinosinusitis Patients

PURPOSE: Asthma exacerbation from human rhinovirus (HRV) infection is associated with deficient antiviral interferon (IFN) secretion. Although chronic rhinosinusitis (CRS), an inflammatory upper airway disease, is closely linked to asthma, IFN-beta responses to HRV infections in human nasal epithelial cells (HNECs) from CRS patients remain to be studied. We evaluated inflammatory and antiviral responses to HRV infection in HNECs from CRS patients. METHODS: HNECs, isolated from turbinate tissue of 13 patients with CRS and 14 non-CRS controls, were infected with HRV16 for 4 hours. The HRV titer, LDH activity, production of proinflammatory cytokines and IFN-beta proteins, and expression levels of RIG-I and MDA5 mRNA were assessed at 8, 24, and 48 hours after HRV16 infection. RESULTS: The reduction in viral titer was slightly delayed in the CRS group compared to the non-CRS control group. IL-6 and IL-8 were significantly increased to a similar extent in both groups after HRV infection. In the control group, IFN-beta production and MDA5 mRNA expression were significantly increased at 8 and 24 hours after HRV16 infection, respectively. By contrast, in the CRS group, IFN-beta was not induced by HRV infection; however, HRV-induced MDA5 mRNA expression was increased, but the increase was slightly delayed compared to the non-CRS control group. The RIG-I mRNA level was not significantly increased by HRV16 infection in either group. CONCLUSIONS: HRV-induced secretion of proinflammatory cytokines in CRS patients was not different from that in the non-CRS controls. However, reductions in viral titer, IFN-beta secretion, and MDA5 mRNA expression in response to HRV infection in CRS patients were slightly impaired compared to those in the controls, suggesting that HRV clearance in CRS patients might be slightly deficient.

Characterisation of divergent flavivirus NS3 and NS5 protein sequences detected in Rhipicephalus microplus ticks from Brazil

Transcripts similar to those that encode the nonstructural (NS) proteins NS3 and NS5 from flaviviruses were found in a salivary gland (SG) complementary DNA (cDNA) library from the cattle tick Rhipicephalus microplus. Tick extracts were cultured with cells to enable the isolation of viruses capable of replicating in cultured invertebrate and vertebrate cells. Deep sequencing of the viral RNA isolated from culture supernatants provided the complete coding sequences for the NS3 and NS5 proteins and their molecular characterisation confirmed similarity with the NS3 and NS5 sequences from other flaviviruses. Despite this similarity, phylogenetic analyses revealed that this potentially novel virus may be a highly divergent member of the genus Flavivirus. Interestingly, we detected the divergent NS3 and NS5 sequences in ticks collected from several dairy farms widely distributed throughout three regions of Brazil. This is the first report of flavivirus-like transcripts in R. microplus ticks. This novel virus is a potential arbovirus because it replicated in arthropod and mammalian cells; furthermore, it was detected in a cDNA library from tick SGs and therefore may be present in tick saliva. It is important to determine whether and by what means this potential virus is transmissible and to monitor the virus as a potential emerging tick-borne zoonotic pathogen.

Host factor Moloney leukemia virus 10 (MOV10) protein inhibits replication of the xenotropic murine leukemia virus-related virus (XMRV) / 病毒学报

We investigated inhibition of Moloney leukemia virus 10 (MOV10) upon xenotropic murine leukemia virus-related virus (XMRV) and made a preliminary study of the mechanism of action. Using transfection, infection, western blotting and real-time polymerase chain reaction, we found that MOV10 inhibited XMRV replication. Using MOV10 overexpressed in viral producer cells, MOV10 was shown to reduce the infectivity of XMRV. MOV10 could be incorporated into XMRV, suggesting that MOV10 could undergo encapsidation by XMRV during viral assembly. MOV10 could also restrict the DNA production of XMRV in target cells. We found that the putative RNA-helicase domain of MOV10 maintained most of its XMRV inhibition. These results suggest that MOV10 could be required during the retroviral lifecycle. Perturbation of MOV10 disrupts the generation of infectious viral particles, suggesting that MOV10 has broad antiretroviral activity. Hence, MOV10 could be actively involved in host defense against retroviral infection.

Method for Japanese encephalitis virus NS3 protease activity analysis and high-throughput screening assay for inhibitors / 生物工程学报

Japanese encephalitis virus (JEV) is a single-stranded and positive-sense RNA, which has a single ORF (open reading frame), encoding a polyprotein precursor. Non-structural protein 3 (NS3) plays an important role in processing the polyprotein precursor and has become an important drug target of flavivirus. In this study, NS2BH-NS3 gene was amplified by PCR and subcloned to the prokaryotic expression plasmid, resulting pET30a-NS2BH-NS3. The fusion protein was expressed in Escherichia coli BL21 (DE3) in soluble form after induction by Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). The recombinant protein was purified by Ni-NTA affinity column. Then a fluorescence resonance energy transfer (FRET) method was used to determine enzymatic activity and the assay conditions were optimized. After screening 113 compounds, we found two compounds inhibiting the activity of NS2BH-NS3. This study provides a convenient and cost-effective method for screening of JEV NS3 protease inhibitor.

Construction of RBM5 vector, establishment of stably transfected A549 cell line and preliminary research on the function of RBM5 gene / 中南大学学报(医学版)

OBJECTIVE@#To establish a stable A549 cell line transfected by RNA binding motif 5 (RBM5) expression vector, and to investigate the effect of RBM5 gene on proliferation of A549 cell line and the expression of DEAH box polypeptide 15 (DHX15).@*METHODS@#The eukaryotic expression vector pcDNA3.1 (+)/RBM5 was constructed by a twostep PCR technique. Then, the recombinant plasmid pcDNA3.1 (+)/RBM5 was verified by DNA sequencing and transfected into the lung adenocarcinoma cell A549. The positive cells with overexpression of RBM5 gene were identified by Western blotting. Flow cytometry was used to analyze the cell cycles of the positive A549 cells [pcDNA3.1 (+)/RBM5-A549] and the negative controls [pcDNA3 .1 (+)- A549]. Finally, RT-PCR was used to detect the expression of DHX15, a splicing-related factor, in the positively transfected A549 cells and the negative controls.@*RESULTS@#A pcDNA3.1 (+)/RBM5 eukaryotic expression vector has been constructed successfully, and the A549 cell line that stably transfected with RBM5 gene has been established. Compared with negative control cells, the percentage of G1 phase cells in the positive cells was increased, while the percentage of S phase was decreased (both P<0.01), and the expression of DHX15 is upregulated (P<0.01).@*CONCLUSION@#RBM5 gene can inhibit the cell cycle and upregulate the expression of DHX15 in A549 cells.

G3BP: a promising target for cancer therapy / 药学学报

G3BP (Ras-GTPase-activating protein SH3 domain binding protein), a protein which binds to RasGAP SH3 domain, belongs to RNA-binding protein family, implicating in the downstream of Ras signaling. G3BP harbors the activities of endoribonuclease and DNA helicase, and can induce stress granules formation. G3BP plays a general role in the signal pathways of cell proliferation, differentiation, apoptosis and RNA metabolism. It has been shown to be over-expressed in a number of human malignancies and has a close relationship with tumor invasion and metastasis. Given that it has been implicated in several pathways that are known to be involved in cancer biology, G3BP may provide a new target for cancer therapy.

DEXH-Box protein DHX30 is required for optimal function of the zinc-finger antiviral protein

The zinc-finger antiviral protein (ZAP) is a host factor that specifically inhibits the replication of certain viruses by eliminating viral mRNAs in the cytoplasm. In previous studies, we demonstrated that ZAP directly binds to the viral mRNAs and recruits the RNA exosome to degrade the target RNA. In this article, we provide evidence that a DEXH box RNA helicase, DHX30, is required for optimal antiviral activity of ZAP. Pull-down and co-immunoprecipitation assays demonstrated that DHX30 and ZAP interacted with each other via their N terminal domains. Downregulation of DHX30 with shRNAs reduced ZAP's antiviral activity. These data implicate that DHX30 is a cellular factor involved in the antiviral function of ZAP.

Sequence analysis, expression and antigenicity detection of bovine viral diarrhea virus NS3 gene / 生物工程学报

In this study, we cloned the NS3 gene from bovine viral diarrhea virus (BVDV) VEDEVAC strain. The result showed that the average P-distance of Pestivirus NS3 amino acid sequence was 0.07 and the VEDEVAC strain was classified to BVDV type 1. Using pET-30a(+) as vector and Escherichia coli Rosetta (DE3) as host, we obtained purified recombinant NS3 protein by Ni-NTA affinity chromatography. Western blotting analysis demonstrated that both BVDV positive serum and classical swine fever virus (CSFV) positive serum were able to recognize the recombinant NS3 protein. Indirect-ELISA assay indicated that the protein could be used as detection antigen.

'DEAD-box' helicase from Plasmodium falciparum is active at wide pH and is schizont stage-specific.

BACKGROUND & OBJECTIVES: DNA helicases catalyse unwinding of duplex DNA in an ATP-dependent manner and are involved in all the basic genetic processes. In order to study these important enzymes in the human malaria parasite we have recently cloned the first full-length 'DEAD-box' helicase gene from Plasmodium falciparum (3D7). In the present study, we report some of the important activities of the encoded protein. METHODS: We have expressed the P. falciparum helicase in Escherichia coli and characterised the encoded biochemically active helicase protein. The characterisation of the protein was carried out using radioactively labeled substrate and the standard strand displacement assay. The localisation of the enzyme was studied using immunofluorescence assay. RESULTS & CONCLUSION: P. falciparum helicase gene is 1551 bp in length and encodes for a protein consisting of 516 amino acid residues with a predicted molecular mass of 59.8 kDa. The protein is designated as Plasmodium falciparum DEAD-box helicase 60 kDa in size (PfDH60). Purified PfDH60 showed ATP and Mg2+ dependent DNA unwinding, ssDNA-dependent ATPase and ATP-binding activities. Interestingly, this is a unique helicase because it works at a wide pH range (from 5.0-10.0). The peak expression of PfDH60 is mainly in schizont stages of the development of P. falciparum, where DNA replication is active. The cell-cycle dependent expression suggests that PfDH60 may be involved in the process of DNA replication and distinct cellular processes in the parasite and this study should make an important contribution in our better understanding of DNA metabolic pathways in the parasite.

Expression of Ras-GTPase-activating protein SH 3 domain binding protein and osteopontin in esophageal squamous carcinoma and their effects on prognosis / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expressions and significances of Ras-GTPase-activating protein SH 3 domain binding protein(G3BP) and osteopontin (OPN) proteins in esophageal squamous carcinoma (ESC).</p><p><b>METHODS</b>The expressions of G3BP and OPN proteins in 80 cases of ESC were detected by immunohistochemistry. The relationships between the 2 protein expression and tumor size, differentiation degree, TNM stage, lymph node metastasis and prognosis of ESC were also explored.</p><p><b>RESULTS</b>(1) The positive expression rate of G3BP in ESC was 71.3%, and the rate in lymphoid metastatic group was significantly higher than that in non lymphoid metastatic group (Z=-2.283, P=0.022), but no relations were found between G3BP expression and diameter of tumor, differentiation and TNM grade (P>0.05). The G3BP positive expression group had shorter survival time than G3BP negative expression group (P=0.000). (2) The positive expression rate of OPN in ESC was 100%, and the degree of OPN expression was correlated with the differentiation (chi(2)=10.766, P=0.005) and lymphoid metastasis (Z=-2.289, P=0.022), but no relationship was found between the diameter of tumor and TNM grade (P>0.05). The expression of OPN were significantly related to survivals in a negative time-dependent manner in ESC patients (P=0.000). (3) The expression of G3BP protein correlated positively with the degree of OPN expression in ESC tissue (r(s)=0.376, P=0.001).</p><p><b>CONCLUSIONS</b>The expressions of G3BP and OPN proteins have a close relationship with lymphoid metastasis and survival in ESC patients. G3BP and OPN proteins can be considered as predictors of prognosis in ESC patients.</p>

Monoclonal antibody against G3BP: preparation, characterization and its application in analysis of human tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To better understand the molecular mechanism of tumorigenesis and progression, the monoclonal antibody against G3BP (Ras-GAP SH3 binding protein), which serves as an important downstream effector of Ras signaling, was prepared, characterized and utilized in analysis of various human tumors.</p><p><b>METHODS</b>By using the prokaryotic expression vector pGEX-5X1, GST-G3BP fusion protein was expressed in E. coli BL21 under induction of IPTG. Purified GST-G3BP fusion protein was used to immunize BALB/c mice. The monoclonal antibody against G3BP was produced through conventional hybridoma method and characterized by ELISA, Western blot and immunohistochemical staining.</p><p><b>RESULTS</b>A hybridoma cell line secreting anti-G3BP IgG1 subtype antibody was obtained. Western blot and competitive inhibition assay showed that the antibody was G3BP-specific. Immunohistochemical staining demonstrated that G3BP was over-expressed in formalin-fixed and paraffin-embedded tissues of some human tumors, such as lung cancer, colon cancer, gastric cancer and breast cancer. In breast cancer specimens, the degree of G3BP expression correlated positively with the presence of lymph node metastasis and c-erbB2 expression.</p><p><b>CONCLUSIONS</b>The G3BP-specific monoclonal antibody derived from recombination protein can be used in ELISA, Western blot and immunohistochemical assay. It may provide an important tool in analysis of G3BP in in vitro and in vivo experiments. Besides, G3BP may serve as another prognostic marker for breast cancer.</p>

Suramin inhibits the in vitro expression of encephalitis B virus proteins NS3 and E / 华中科技大学学报（医学）（英德文版）

In this study, the mechanism by which Suramin inhibits the replication of epidemic encephalitis B virus was explored to provide a theoretical basis for its further application in clinical practice. After viral infection of HepG2 and IMR-32 cells, different concentrations of Suramin were added to the culture media, and then the cultural supernatants and infected cells were collected 48 h later. For the evaluation of the curative effect, cytopathic effect (CPE), virus titers, the expression of viral protein and viral RNA were determined by Western blot, RT-PCR and in vitro RNA synthesis, respectively. At the concentration of 50 microg/ml of Suramin, HepG2 and IMR-32 infected with epidemic encephalitis B virus decreased by 51.8% and 0.03% respectively, as compared with controls. It was suggested that expression of encephalitis B virus proteins NS3 and E was notably reduced by Suramin. This is especially true of E protein. At RNA level, however, no difference in RNA virus was found between Suramin-treated virus and non-treated cells. Our results suggest that Suramin can inhibit viral replication by blocking the production of viral proteins.

Characterization and E protein expression of mutant strains during persistent infection of KN73 cells with Japanese encephalitis virus / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To study the character of mutants originating from Japanese encephalitis viruses and the relationship between the characterization of mutant strains and E protein expression.</p><p><b>METHODS</b>Persistent infection was established with standard strains of Japanese encephalitis viruse, known as parental viruse, in a human hepatoma cell line, KN73. Cells were subcultured weekly using trypsinization techniques. Cell-associated viruses of persistently infected cells were collected by a freeze and thaw method. Virus titers were examined by plaque method using baby hamster kidney (BHK) cells. Indirect immunofluorescence assays were used to examine E and NS3 protein antigens. Western blot analysis was used to test expression of E and NS3 proteins.</p><p><b>RESULTS</b>In the early phase (24 - 36 h) post-infection, virus titer in culture fluid from KN73 cells infected with parental viruses were 10(6) PFU/ml. They were 10(3 - 4) PFU/ml in the late phase (3 years) post-infection. The titer of cell-associated viruse was 10(2 - 3) PFU/ml. A virus super-infection assay found that virus titers in culture fluid from persistently infected KN73 cells acutely super- infected with parental viruses were much lower than that of culture fluids in acutely infected normal KN73 at the same phase. Indirect immunoflurescence assay revealed that the quantity of viral antigens in persistently infected KN73 cells was lower than that in acutely infected KN73 cells with parental viruses. Western blot analyses indicated that the molecular weights of E and NS3 proteins were 53 kD and 73 kD, respectively. Expression of NS3 protein in persistently infected KN73 cells was stable but expression of E protein was markedly suppressed.</p><p><b>CONCLUSIONS</b>The virulence and reproduction of viruses obtained from persistently infected KN73 cells, which have some features of DI viruses and were involved in persistent infection, was lower than that of parental viruses. These mutants may have be related to the decrease in E protein expression.</p>

Molecular characterization of DDX26, a human DEAD-box RNA helicase, located on chromosome 7p12

DEAD-box proteins comprise a family of ATP-dependent RNA helicases involved in several aspects of RNA metabolism. Here we report the characterization of the human DEAD-box RNA helicase DDX26. The gene is composed of 14 exons distributed over an extension of 8,123 bp of genomic sequence and encodes a transcript of 1.8 kb that is expressed in all tissues evaluated. The predicted amino acid sequence shows a high similarity to a yeast DEAD-box RNA helicase (Dbp9b) involved in ribosome biogenesis. The new helicase maps to 7p12, a region of frequent chromosome amplifications in glioblastomas involving the epidermal growth factor receptor (EGFR) gene. Nevertheless, co-amplification of DDX26 with EGFR was not detected in nine tumors analyzed