• Journal of Gastric Cancer
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• v.20 no.2
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• pp.139-151
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• 2020

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

• Journal of Life Science
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• v.28 no.4
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• pp.478-482
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• 2018

Human rotavirus is a causative agent of acute diarrhea among children. The artificial gene encoding the truncated $VP8^*$ protein of human rotavirus A (serotype 1 strain WA) was synthesized according to the Escherichia coli codon preference. The synthetic $VP8^*$ gene also possessed the NdeI and HindIII restriction sites for the convenient in-frame cloning for translation and a 6-histidine tag at C-terminus for Ni+ affinity purification. Molecular weight of the truncated $VP8^*$ protein deduced from the nucleotide sequences of the artificial gene was a 19.7-kDa. This synthetic $VP8^*$ DNA fragment was inserted into the pT7-7 expression vector and transformed into E. coli BL21 (DE3). Transformants harboring the synthetic gene encoding the $VP8^*$ protein was induced by supplement of a final concentration of 0.05 mM ITPG at $20^{\circ}C$. Protein crude extract from the E. coli transformants was subjected to Western blotting with the mouse anti-rotavirus capsid antibody, showing ~20-kDa $VP8^*$ protein band. The truncated $VP8^*$ protein band was also observed by Western blotting using the rabbit polyclonal antibody serum made against the truncated $VP8^*$ protein. This study suggested that the synthetic gene could be used as an easy way to produce the antigenic vaccine candidate for control of virus-associated diseases or to develop antibodies for diagnostic purpose.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3781-3789
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• 2012

Background: Pancreatic cancer is one of the most aggressive tumors with a dismal prognosis. The membrane cytoskeletal crosslinker Ezrin participates in several functions including cell proliferation, adhesion, motility and survival. There is increasing evidence that Ezrin is overexpressed in vast majority of malignant tumors and regulates tumor progression. However, its roles in pancreatic cancer remain elusive. Methods: Three pairs of specific Ezrin siRNAs were designed and synthetized and screened to determine the most efficient one for construction of a hairpin RNA plasmid targeting Ezrin. After transfection into the Panc-1 pancreatic cancer cell line, real-time quantitative PCR and Western blotting were performed to examine the expression of mRNA and protein. The MTT method was applied to examine the proliferation and the drug sensibility to Gemcitabine. Flow cytometry was used to assess the cycle and apoptosis, while capacity for invasion was determined with transwell chambers. Furthermore, we detected phosphorylated-Erk1/2 protein and phosphorylated-Akt protein by Western blotting. Results: Real-time quantitative PCR and Western blotting revealed that Ezrin expression was notably down-regulated at both mRNA and protein levels by RNA interference (P< 0.01). Proliferation was inhibited and drug resistance to gemcitabine was improved (P< 0.05). Flow cytometry showed that the proportion of cells in the G1/G0 phase increased (P< 0.01), and in G2/M and S phases decreased (P< 0.05), with no apparent differences in apoptosis (P> 0.05). The capacity for invasion was markedly reduced (P< 0.01). In addition, down-regulating Ezrin expression had no effect on phosphorylated-Akt protein (P>0.05), but could decrease the level of phosphorylated-Erk1/2 protein (P< 0.05). Conclusions: RNA interference of Ezrin could inhibit its expression in the pancreatic cancer cells line Panc-1, leading to a potent suppression of malignant behavior in vitro. Assessment of potential as a target for pancreatic cancer treatment is clearly warranted.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7825-7829
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• 2014

Objective: To investigate the effect of high expression of XAF1 in vivo or in vitro on lung cancer cell growth and apoptosis. Methods: 1. The A549 human lung cancer cell line was transfected with Ad5/F35 - XAF1, or Ad5/F35 - Null at the same multiplicity of infection (MOI); (hereinafter referred to as transient transfected cell strain); XAF1 gene mRNA and protein expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively. 2. Methyl thiazolyl tetrazolium (MTT) and annexin V-FITC/PI double staining were used to detect cell proliferation and apoptosis before and after infection of Ad5/F35 - XAF1 with Western blotting for apoptosis related proteins, caspase 3, caspase - 8 and PARP. 3. After the XAF1 gene was transfected into lung cancer A549 cells by lentiviral vectors, and selected by screening with Blasticidin, reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were applied to detect mRNA and protein expression, to establish a line with a stable high expression of XAF1 (hereinafter referred to as stable expression cell strain). Twenty nude mice were randomly divided into groups A and B, 10 in each group: A549/XAF1 stable expression cell strain was subcutaneously injected in group A, and A549/Ctrl stable cell line stable expression cell strain in group B (control group), to observe transplanted tumor growth in nude mice. Results: The mRNA and protein expression of XAF1 in A549 cells transfected by Ad5/F35 - XAF1 was significantly higher than in the control group. XAF1 mediated by adenovirus vector demonstrated a dose dependent inhibition of lung cancer cell proliferation and induction of apoptosis. This was accompanied by cleavage of caspase -3, -8, -9 and PARP, suggesting activation of intrinsic or extrinsic apoptotic pathways. A cell strain of lung cancer highly expressing XAF1 was established, and this demonstrated delayed tumor growth after transplantation in vivo. Conclusion: Adenovirus mediated XAF1 gene expression could inhibit proliferation and induce apoptosis in lung cancer cells in vitro; highly stable expression of XAF1 could also significantly inhibit the growth of transplanted tumors in nude mouse, with no obvious adverse reactions observed. Therefore, the XAF1 gene could become a new target for lung cancer treatment.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.83-94
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• 2004

Objective: To investigate whether GnRH-agonist (GnRH-Ag) using in IVF-ET affects apoptosis of human granulosa-luteal cells and expression of peripheral benzodiazepine receptor (PBR) protein involved in the apoptosis of the cells. Methods: Granulosa-luteal cells obtained during oocyte retrieval were cultured and treated with $10^{-5}M$ GnRH-Ag. Apoptosis of the cells by the treatment was confirmed using DNA fragmentation analysis 24 h after culture. The presence of PBR protein within the cells was examined by immunofluorescence staining and the expression of the protein was analyzed by Western blotting. In addition, it was measured for progesterone and nitric oxide (NO) produced by granulosa-luteal cells after GnRH-Ag treatment. To evaluate the relationship between NO production and PBR expression, sodium nitroprusside (SNP) as a NO donor was added in media and investigated the expression of PBR protein by Western blotting. Results: Apoptosis increased in the granulosa-luteal cells 24 h after GnRH-Ag treatment, whereas the expression of PBR protein significantly decreased. Furthermore, the production of progesterone and nitric oxide (NO) by the cells significantly fell from 12 h after the treatment. In the results of Western blotting after SNP treatment, the expression of PBR protein increased in the treatment with SNP alone to the granulosa-luteal cells, but was suppressed in the treatment with GnRH-Ag and SNP. Additionally, the staining result of PBR protein in the cells showed the even distribution of it through the cell. Conclusion: These results demonstrate that GnRH-Ag treatment induces apoptosis, decreasing expression of PBR protein and NO production in human granulosa-luteal cells. The present study suggests that one of the apoptosis mechanism of human granulosa-luteal cells by GnRH-Ag might be a signal transduction pathway via NO and PBR.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.77-90
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• 1996

Nucleocapsid protein (NP)which exists in the particle of hantavirus and surrounds the viral RNA genome is one of the major structural proteins and plays role of antigen to elicit the antibody detected predorminantly right after infection of the virus in the patients of hemorragic fever with renal syndrome (HFRS)or experimental animals. NP is important target antigen in serological diagnostic system of HFRS utilizing whole antigens from the native virus particle, such as IFA, ELISA and Western blotting. Therefore, the preparation of this protein in the level of higher quantity and purity is desirasble for developed dianosis of the disease. The purpose of this study is the cloning of NP gene which exists in the S genome segment of Maaji (MAA) virus and expression of the gene to obtain qualified, genetically engineered NP to be utilized as an immunodiagnostic antigen. First of all, for the purpose of amplifing the MAA-NP gene by PCR, the specific primers were built from the known nucleotide sequence of Hantaan viral NP gene. The viral cDNA of the NP gene was synthesized by using the primers and RNase $H^-$ AMV reverse transcriptase. Thereafter, using this cDNA as a template, the NP gene was amplified specifically by Taq DNA polymrerase. The pT7blue (R)T-overhang vector systems were used for cloning of the amplified NP gene. The expression system was consisted of BL21 (DE3)pLysS and pET16b as a host and a plasmid repectively. Into Ndel site of pET16b, NP gene was ligated with cohesive end for the expression. Insertion of NP gene in the plasmid was confirmed by PCR and mini prep methods. For expression, IPTG was used and the expressed protein was characterized by Western blotting. The MAA-NP was expressed as the form of inclusion body (insoluble fraction)and the protein purified by affinity and metal chealating columns reacted specifically with the sera from patients of HFRS as to be tested by ELISA and Western blotting.

• Journal of fish pathology
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• v.7 no.1
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• pp.13-22
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• 1994

To identify the immunogens of a PRT strain of Infectious Hematopoietci Necrosis Virus (IHNV) isolated from cultrued fish in Korea (Park et al, 1993). a panel of 4 monoclonal antibodies (MAbs) against IHNV-PRT strain and two polyclonal antisera from rainbow trout survived IHN disease were prepared. Proteins of purified IHNV-PRT strain were analysed on 10% SDS-PAGE and transferred onto NC paper and were incubated with the antibody solutions. With the polyclonal antibodies, four bands ($M_1$, $M_2$, G and 90Kd) were detected and the band density was in the order of $M_2$ > 90Kd > $M_1$ > G. However, with the MAbs, only two bands(G and 90Kd) were detected. The origin of 90Kd protein was not clear but maybe cell. All the results represented that among the five proteins of IHNV-PRT strain (Park et al., 1993), $M_2$, $M_1$ and G proteins were immunogens and $M_2$ protein was the strongest one.

• The Journal of Korean Medicine
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• v.19 no.1
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• pp.145-164
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• 1998

The purpose of this study is to evaluate the effect of Injinchunggantang-derivative on proliferation of hepatocyte in rats. Cell viability is studied by MTI assay. The gene related to cell replication such as p53, waf1, bcl-2 and $bcl-_{X_L}$ is quantitized by quantitative RT-PCR and the proteins coded by these genes are studied by Western blotting. The results are as follows. 1. The hepatocytes cultured in medium with lnjinchunggantang-derivative showed better viability compared with control grroup in MTI assay, and the hepatocytes cultured in medium with the Injinchunggantang-derivative-and-ethanol-mixed group showed better viability than the hepatocytes cultrued in 10% ethanol culture medium(control group), noting that Injinchunggantang-derivative has protective effect on hepatocyte injury. There was no dose- and time-dependence. 2. In quantitative RT-PCR, i) Bel-2 gene increased significantly both in Injinchunggantang-derivative group and in Injinchunggantang-derivative-and-ethanol-mixed group, while it showed no significant increase or decrease in other group. ii) $Bcl-_{X_L}$ gene increased significantly in Injinchunggantang-derivative group as well as in Injinchunggantang-deri vative-and-ethanol -mixed group. iii) P53 gene showed no significant increase or decrease in hepatocytes cultured in medium with 10% ethanol and in hepatocytes cultured in medium with Injinchunggantang-derivative-and-ethanol-mixed group, suggesting that 10% ethanol induced cell toxicity, thus increased p53 gene expression. iv) Wafl gene showed no significant increase or decrease in hepatocytes cutured in medium with Injinchtrnggantang-derivative, while increased in hepatocytes cultured in medium with 10% ethanol and in hepatocytes cultured in medium with Injinchtrnggantang-derivative-andethanol-mixed group, suggesting that 10% ethanol induced cell toxicity increased wafl gene expression. 3. In the study on protein by western blotting, the band of bcl-2 and $bcl-_{X_L}$ were widened in Injinchtrnggantang-derivative group. Especially the amount of $bcl-_{X_L}$ increased significantly compared with other groups. But in the study on p53 and wafl, there was no significant difference among those groups. Above study shows that Injinchunggantang-derivative has good effect on cell viability and that the genes resistant to cell death such as bcl-2 and $bcl-_{X_L}$ are induced by Injinchunggantang-derivative to resist to cell death by toxic agent And this is reconfirmed in protein study using' western blotting: These results suggest that Injinchunggantang-derivative has inhibitory effect on cell death as well as protective effect on hepatocyte. Therefore this prescription is recommended in various liver diseases such as chronic liver disease and-induced hepatic injury.

• Tuberculosis and Respiratory Diseases
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• v.56 no.4
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• pp.381-392
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• 2004

Arsenic trioxide($As_2O_3$) was introduced into the treatment of refractory or relapsed acute promyelocytic Ieukemia. Some investigators have reported that arsenic trioxide had induced apoptosis in a variety of solid human tumor cell lines, including non-small cell lung cancer. Non-steroidal anti-inflammatory drugs(NSAIDs) are powerful chemopreventive agents for gastrointestinal cancers and the growth of established tumors are reduced by inducing apoptosis. It's also reported that NSAIDs enhanced tumor response to chemotherapeutic drugs or radiation. In this study, we aimed to determine whether combination of arsenic trioxide with sulindac augmented its apoptotic potential in NCI-H157 human lung cancer cells. The human lung cancer cell line NCI-H157 was treated with arsenic trioxide and sulindac. Cell viability was measured by the MTT assay. Apoptosis was measured by nuclear staining and flow cytometric analysis. The catalytic activity of the caspase families were measured by the fluorogenic cleavage of biosubstrates. The western blotting were also performed to define the mechanical basis of apoptosis. Combination treatment of arsenic trioxide and sulindac decreased the viability of NCI-H157 human lung cancer cells in a dose-dependent manner. The catalytic activity of caspase-3, 8 and 9 proteases were increased after combination treatment. Consistently PARP was cleaved from 116kDa to 85kDa fragments, and the expression of ICAD was decreased by time-dependent manner. Also combination treatment increased the expression of Fas and Fas/L. Combination therapy of arsenic trioxide with sulindac augments cell death and induces apoptosis via the activation of caspase cascade in NCI-H157 human lung carcinoma cells.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.253-263
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• 2006

Objective: Identification of the regulatory mechanism for arrest and initiation of primordial follicular growth is crucial for female fertility. Previously, we found 15 expressed sequence tags (ESTs) that were specifically abundant in the day-S-subtracted cDNA library and that the B357 clone was novel. The present study was conducted to obtain the whole sequence of the novel gene including B357 and to characterize its mRNA and protein expression in mouse ovary and testis. Methods: The extended sequence of the 2,965-bp cDNA fragment for the clone B357 was named ${\underline{5}}-{\underline{d}}ay-{\underline{o}}vary-{\underline{s}}pecific\;gene-{\underline{1}}$ (5DOS1) and submitted to GenBank (accession number ${\underline{AY751521}}$). Expression of 5DOS1 was characterized in both female and male gonads at various developmental stages by Northern blotting, real-time RT-PCR, in situ hybridization, Western blotting, and immunohistochemistry. Results: The 5DOS1 transcript was highly expressed in the adult testis, brain, and muscle as compared to the other tissues. In the ovary, the 5DOS1 transcript was detected in all oocytes from primordial to antral follicles, and highly expressed at day 5 after birth and decreased thereafter. In contrast, expression of 5DOS1 showed a gradual increase during testicular development and its expression was limited to various stages of male germ cells except spermatogonia. Conclusions: This is the first report on the expression and characterization of the 5DOS1 gene in the mouse gonads. Further functional analysis of the 5DOS1 protein will be required to predict its role in gametogenesis.