• BMB Reports
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• v.40 no.5
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• pp.814-824
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• 2007

Liver cirrhosis (LC) is defined as comprising diffuse fibrosis and regenerating nodules of the liver. The biochemical and anatomical dysfunction in LC results from both reduced liver cell number and portal vascular derangement. Although several studies have investigated dysregulated genes in cirrhotic nodules, little is known about the genes implicated in the pathophysiologic change of LC or about their relationship with the degree of decompensation. Here, we applied cDNA microarray analysis using 38 HBsAg-positive LC specimens to identify the genes dysregulated in HBV-associated LC and to evaluate their relation to disease severity. Among 1063 known cancer- and apoptosis-related genes, we identified 104 genes that were significantly up- (44) or down- (60) regulated in LC. Interestingly, this subset of 104 genes was characteristically correlated with the degree of decompensation, called the Pugh-Child classification (20 Pugh-Child A, 10 Pugh-Child B, and 8 Pugh-Child C). Patient samples from Pugh-Child C exhibited a distinct pattern of gene expression relative to those of Pugh-Child A and B. Especially in Pugh-Child C, genes encoding hepatic proteins and metabolizing enzymes were significantly down-regulated, while genes encoding various molecules related to cell replication were up-regulated. Our results suggest that subsets of genes in liver cells correspond to the pathophysiologic change of LC according to disease severity and possibly to hepatocarcinogenesis.

• BMB Reports
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• v.38 no.1
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• pp.34-40
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• 2005

GLPG (Ganoderma lucidum proteoglycan) was a bioactive fraction obtained by the liquid fermentation of the mycelia of Ganoderma lucidum, EtOH precipitation, and DEAE-cellulose column chromatography. GLPG was a proteoglycan with a carbohydrate: protein ratio of 10.4: 1. Its antiviral activities against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) were investigated using a cytopathic inhibition assay. GLPG inhibited cell death in a dose-dependent manner in HSV-infected cells. In addition, it had no cytotoxic effect even at 2 mg/ml. In order to study the mode of action of the antiviral activity of GLPG, cells were treated with GLPG before, during, and after infection, and viral titer in the supernatant of cell culture 48 h post-infection was determined using a $TCID_{50}$ assay. The antiviral effects of GLPG were more remarkable before viral treatment than after treatment. Although the precise mechanism has yet to be defined, our work suggests that GLPG inhibits viral replication by interfering with the early events of viral adsorption and entry into target cells. Thus, this proteoglycan appears to be a candidate anti-HSV agent.

• BMB Reports
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• v.48 no.2
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• pp.121-126
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• 2015

Here we report a new chemical inhibitor against HIV-1 with a novel structure and mode of action. The inhibitor, designated as A1836, inhibited HIV-1 replication and virus production with a 50% inhibitory concentration ($IC_{50}$) of $2.0{\mu}M$ in an MT-4 cell-based and cytopathic protection antiviral assay, while its 50% cytotoxic concentration ($CC_{50}$) was much higher than $50{\mu}M$. Examination of the effect of A1836 on in vitro HIV-1 reverse transcriptase (RT) and integrase showed that neither were molecular targets of A1836. The characterization and re-infection assay of the HIV-1 virions generated in the presence of A1836 showed that the synthesis of early RT products in the cells infected with the virions was inhibited dose-dependently, due in part to abnormal protein formation within the virions, thus resulting in an impaired infectivity. These results suggest that A1836 might be a novel candidate for the development of a new type of HIV-1 inhibitor.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.328-333
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• 2008

A series of pep tides binding to the HCV NS5B polymerase was selected from phage display peptide libraries. A conserved motif of Ser-Arg-X-Arg/Leu was identified among the selected peptides, and Pep2 (Trp-Ser-Arg-Pro-Arg-Ser-Leu) was chosen for further characterization. The binding of Pep2 to HCV NS5B in vivo was shown by a yeast two-hybrid assay and by subcellular colocalization analysis using immunofluorescence confocal microscopy. The in vitro interaction was also confirmed by GST pulldown assay. The replication of the HCV 1b subgenomic replicon was efficiently inhibited by the presence of the peptide. By using a subtractive biopanning against Pep2, the binding site of the peptide was mapped at the pocket of Pro388 to Pro391 in the thumb subdomain of the polymerase. A yeast two-hybrid analysis using Pro388Ala and Pro391Ala mutants of NS5B confirmed the binding.

• Journal of Microbiology
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• v.35 no.2
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• pp.152-157
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• 1997

Infection of human fibroblast (HF) cells with human cytomegalovirus (HCMV) result in changes in the intracellular level of second messengers. Since nitric oxide (NO) production has been known to be related with other second messengers, it is probable that HCMV infection of HF cells may involve NO. To test this possibility, the amount of NO was measured following ogenous addition of NO generators such as sodium nitroprusside (SNP) or S-nitroso-N-a-cetylpenicillamine (SNAP) immediately after HCMV infection, however, inhibited virus multiplication. Furthermore, immunoblot experiment using monoclonal antibody to HCMV major immediate early (MIE) proteins or CAT assay using pCMVIE/CAT (plasmid containing CAT gene driven by HCMV MIE promoter) revealed that SNP or SNAP blocked the MIE gene expression. SNP was more effective than SNAP in hibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP in inhibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP. Although the mechanism for the inhibition of HCMV multiplication and MIE gene expression by NO is still elusive some correlation with NO-mediated inhibition of HCMV-induced increase in cytosolic free Ca$\^$2+/ concentration ([Ca$\^$2+/]) was observed. The increase of [Ca$\^$2+/] following HCMV infection was inhibited by SNP, and less effectively by SNAP. Raising [Ca$\^$2+/ with bromo-A23187 partially reversed the SNP block of MIE gene expression. Thus, there appear to e some relationships among NO. [Ca$\^$2+/], and HCMV MIE gene expression.

• BMB Reports
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• v.48 no.8
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• pp.454-460
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• 2015

Naturally occurring reoviruses are live replication-proficient viruses that specifically infect human cancer cells while sparing their normal counterpart. Since the discovery of reoviruses in 1950s, they have shown various degrees of safety and efficacy in pre-clinical or clinical applications for human anti-cancer therapeutics. I have recently discovered that cellular tumor suppressor genes are also important in determining reoviral tropism. Carcinogenesis is a multi-step process involving the accumulation of both oncogene and tumor suppressor gene abnormalities. Reoviruses can exploit abnormal cellular tumor suppressor signaling for their oncolytic specificity and efficacy. Many tumor suppressor genes such as p53, ataxia telangiectasia mutated (ATM), and retinoblastoma associated (RB) are known to play important roles in genomic fidelity/maintenance. Thus, a tumor suppressor gene abnormality could affect host genomic integrity and likely disrupt intact antiviral networks due to the accumulation of genetic defects which in turn could result in oncolytic reovirus susceptibility. This review outlines the discovery of oncolytic reovirus strains, recent progresses in elucidating the molecular connection between oncogene/tumor suppressor gene abnormalities and reoviral oncotropism, and their clinical implications. Future directions in the utility of reovirus virotherapy is also proposed in this review. [BMB Reports 2015; 48(8): 454-460]

• BMB Reports
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• v.39 no.5
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• pp.571-577
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• 2006

Dendrolimus punctatus tetravirus (DpTV) has been identified as a new member of the genus Omegatetravirus of the family Tetraviridae that may be related serologically to Nudaurelia capensis virus ($N{\omega}V$). To establish the function of DpTV RNA genome and to better understand the mechanism of viral replication, the putative RNA-dependent RNA polymerase (RdRp) domain has been cloned and expressed in Escherichia coli. The recombinant protein was purified on a Ni-chelating HisTrap affinity column and demonstrated to initiate viral RNA synthesis in a primer-independent manner but not by terminal nucleotidyle transferase activity in the presence of $Mg^{2+}$ and RNA template. Mutation of the GDD to GAA interferes with the residues at the polymerase active site and metal ions, and thus renders the polymerase inactive.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.454-459
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• 2013

The Potexvirus Alternanthera mosaic virus (AltMV) has multifunctional triple gene block (TGB) proteins, among which our studies have focused on the properties of the TGB1 protein. The TGB1 of AltMV has functions including RNA binding, RNA silencing suppression, and cell-to-cell movement, and is known to form homologous interactions. The helicase domains of AltMV TGB1 were separately mutated to identify which regions are involved in homologous TGB1 interactions. The yeast two hybrid system and Bimolecular Fluorescence Complementation (BiFC) in planta were utilized to examine homologous interactions of the mutants. Helicase motif I of AltMV TGB1 was found to be critical to maintain homologous interactions. Mutations in the remaining helicase motifs did not inhibit TGB1 homologous interactions. In the absence of homologous interaction of TGB1, subcellular localization of helicase domain I mutants showed distinctively different patterns from that of WT TGB1. These results provide important information to study viral movement and replication of AltMV.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.113-125
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• 1998

The neurotropic psudorabies virus(PRV) to replicate within neurons is very useful pathogen for neuronal tracing. I carried out this study to investigate the parametric analysis on the viral infection in the rat circadian control center with two genetically engineered strains out of PRV. The two strains are isogenic with the attenuated Bartha strain of PRV ; in one strain a lacZ reporter gene was inserted into the gC locus (PRV-BaBlu ; $4.75\times10^8pfu/ml$) and the other strain contained a PRV envelope glycoprotein gene(PRV-D ; $2.5\times10^8pfu/ml$) theat is absent in PRV-BaBlu. simultaneous or temporally separated sequential injection of$2{\mu}l$ of each strain into the vetreous body of eye produced a course of transsynaptic infection of retinohypothalamic circuitry. The results were as follows; 1. PRV-BaBlu and PRV-D infected the suprachiasmatic nucleus in hypothalamus and intergeniculate leaflet in lateral geniculate nucleus of thalamus. 2. The rate of PRV infection was dependent upon PRV strain. 3. Pre-infected neurons by PRV-D were interfered with the replication of PRV-BaBlu. 4. Dual injection of PRV-D and PRV-BaBlu showed more virulent than the parental strain.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.431-435
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• 2012

In this study, we describe a novel approach to achieve replicative selectivity of conditionally replicative adenovirus that is based upon trans-splicing ribozyme-mediated replacement of cancer-specific RNAs. We developed a specific ribozyme that can reprogram human telomerase reverse transcriptase (hTERT) RNA to induce adenoviral E1A gene expression selectively in cancer cells that express the RNA. Western blot analysis showed that the ribozyme highly selectively triggered E1A expression in hTERT-expressing cancer cells. RT-PCR and sequencing analysis indicated that the ribozyme-mediated E1A induction was caused via a high fidelity trans-splicing reaction with the targeted residue in the hTERT-expressing cells. Moreover, reporter activity under the control of an E1A-dependent E3 promoter was highly transactivated in hTERT-expressing cancer cells. Therefore, adenovirus containing the hTERT RNA-targeting trans-splicing ribozyme would be a promising anticancer agent through selective replication in cancer cells and thus specific destruction of the infected cells.