• KSBB Journal
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• v.16 no.6
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• pp.579-591
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• 2001

The cell growth inhibitor effect of cervical cancer cells was investigated by liposome mediated transfection (pRcCMVp53/lipofectin) and by transfection using adenovirus (AdCMVp57). The papilloma virus cancer cell lines we used in this study were HPV16 positive, having inhibiter gene, wild p53 gene, CaSki, SiHa, HPV18 positive HeLa, HeLaS3 and HPV negative C33A, HT3. LacZ gene of E.coli was used as the marker gene for the transfection efficiency. The effect on the inhibition of tumor cell growth was measured by cell count and cell viability though ELISA analysis and MTT assay. The inhibition of tumor cell growth was confirmed by measuring each assay for six days, comparing with the normal control cell growth. The cell growth of cervical cancer calls by transfection was significantly reduced and showed tittle differences among the cell lines. To eliminate the potential problem of Ad(adenovirus) contamination during rAAV production, rAAV can be produced by a triple transfection of vector plasmic, packaging plasmid, and adenovirus helper plasmid. To examine the helper functions of Ad plasmids on the production of rAAV vector, we carried out cotransfection of three plasmids, AAV vector, packaging construct, and Ad helper plasmids. The optimized transfection condition for calcium phosphate method is 25ug of total DNA per 10-cm-diameter plate of 293 cell. We found that rAAV yields peaked at 48hr after Ad infection. The titer of rAAV was measured by the dot blot analysis to measure the number of particles/ml based on the quantification of viral DNA. Recent1y, Kombucha(fungi) was identified as a very potent antileukefic agent. In the present study, effect of natural toxin(plankton) and Kombucha is PSP(GTXI-3, neoSTX), on various MTT assay cervical cancer cell line. Toxin(GTX 1-3, neoSTX) also inhibited the proliferation in primary cervical cancer calls in a dose-dependent toxin concentration. These results showed that toxin was very potent in inhibiting the proliferation of cervical cancer calls in vitro. Toxins and Kombuoha exhibited a dose dependent inhibition of cellular proliferation in cancer cell line.

• Molecules and Cells
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• v.27 no.6
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• pp.621-627
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• 2009

Spinocerebellar ataxia type 1 (SCA1) is an autosomal-dominant neurodegenerative disorder characterized by ataxia and progressive motor deterioration. SCA1 is associated with an elongated polyglutamine tract in ataxin-1, the SCA1 gene product. As summarized in this review, recent studies have clarified the molecular mechanisms of SCA1 pathogenesis and provided direction for future therapeutic approaches. The nucleus is the subcellular site where misfolded mutant ataxin-1 acts to cause SCA1 disease in the cerebellum. The role of these nuclear aggregates is the subject of intensive study. Additional proteins have been identified, whose conformational alterations occurring through interactions with the polyglutamine tract itself or non-polyglutamine regions in ataxin-1 are the cause of SCA-1 cytotoxicity. Therapeutic hope comes from the observations concerning the reduction of nuclear aggregation and alleviation of the pathogenic phenotype by the application of potent inhibitors and RNA interference.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.796-805
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• 1997

Background : It is clear that deregulation of cell cycle progression is a hallmark of neoplastic transformation and genes involved in the $G_1$/S transition of the cell cycle are especially frequent targets for mutations in human cancers, including lung cancer. p16 gene product, one of the G1 cell-cycle related proteins, that is recently identified plays an important role in the negative regulation of the the kinase activity of the cyclin dependent kinase (cdk) enzymes. Therefore p16 gene is known to be an important tumor suppressor gene and is also called MTS1 (multiple tumor suppressor 1). No more oncogenes have been reported to be frequently related to multiple different malignancies than the alterations of p16 gene. Especially when it comes to non-small cell lung cancer, there was no expression of p16 in more than 70% of cell lines examined. And also it is speculated that p16 gene could exert a key role in the development of non-small cell lung cancer. This study was designed to evaluate whether p16 gene could be used as a candidate for gene therapy of non-small cell lung cancer. Methods : After the extraction of total RNA from normal fibroblast cell line and subsequent reverse transcriptase reaction and polymerase chain reaction, the amplified p16 cDNA was subcloned into eukaryotic expression plasmid vector, pRC-CMV. The constructed pRC-CMV-p16 was transfected into the NCI-H441 NSCLC cell line using lipofectin. The changes of G1 cell-cycle related proteins were investigated with Western blot analysis and immunoprecipitation after extraction of proteins from cell lysates and tumor suppressive effect was observed by clonogenic assay. Results : (1) p16(-) NCI-H441 cell line transfected with pRC-CMV-p16 showed the formation of p16 : cdk 4 complex and decreased phosphorylated Rb protein, while control cell line did not. (2) Clonogenic assay demonstrated that the number of colony formation was markedly decreased in p16(-) NCI-H441 cell line transfected with pRC-CMV-p16 than the control cell line. Conclusion : It is confirmed that the expression of p16 protein in p16 absent NSCLC cell line with the gene transfection leads to p16 : cdk4 complex formation, subsequent decrease of phosphorylated pRb protein and ultimately tumor suppressive effects. And also it provides the foundation for the application of p16 gene as a important candidate for the gene therapy of NSCLC.

• BMB Reports
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• v.34 no.2
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• pp.176-181
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• 2001

Using a retrovirus, foreign genes can be introduced into mammalian cells. The purpose of this study is to produce a retrovirus that can make the infected cells express two genes; the human multidrug resistance gene (MDR1) and the HLA-B7 gene, which is one of the major human histocompatibility complex (MHC) class I genes. For the expression of these genes, the internal ribosome entry site (IRES) was used, which was derived from the encephalomyocarditis (EMC) virus. In order to produce retroviruses, a retroviral vector was transfected into a packaging cell line and the transfected cells were treated with vincristine, which is an anti-cancer drug and a substrate for the MDRI gene product. This study revealed that two genes were incorporated into chromosomes of selected cells and expressed in the same cells. The production of the retrovirus was confirmed by the reverse transcription (RT)-PCR of the viral RNA. The retrovirus that was produced infected mouse fibroblast cells as well as the human U937. This study showed that packaging cells produced the retroviruses, which can infect the target cells. Once the conditions for the high infectivity of retrovirus into human cells are optimized, thus virus will be used to infect hematopoietic stem cells to co-express MDRl and HLA-B7 genes, and develop the lymphocytes that can be used for the immnogene therapy.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.62-73
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• 2004

Purpose: The herpes simplex virus type 1 thymidine kinase gene(HSV1-tk) is an attractive candidate as a reporter gene in noninvasive reporter gene monitoring system. The HSV1-tk gene was chosen as a reporter gene, because it has been extensively studied, and there are appropriate reporter probes, substrates of HSV1-tk gene product, to apply for HSV1-tk gene imaging. We used radiolabeled 5-iodovinyl-2'-deoxyuridine (IVDU) and 5-iodovinyl-2'-fluoro-2'-deoxyuridine (IVFRU) as reporter probes for HSV1-tk gene monitoring system. Materials and Methods: We prepared HSV1-tk gene transduced Morris hepatoma cell line using retroviral vector, MOLTEN containing HSV1-tk gene. And we confirmed the HSV1-tk gene expression by Northern blotting and Western blotting. We compared in vitro uptakes of radioiodinated IVDU and IVFRU to monitor HSV1-tk gene expression in Morris hepatoma cell line (MCA) and HSV1-tk gene tranduced MCA (MCA-tk) cells until 480 minutes. We also peformed correlation analysis between percentage of HSV1-tk gene tranduced MCA cell % (MCA-tk%) and uptakes of radiolabeled IVDU or IVFRU. Results: MCA-tk cell expressed HSV1-tk mRNA and HSV1-TK protein. Two compounds showed minimal uptake in MCA, but increased uptake was observed in MCA-tk. IVDU showed 4-fold higher accumulation than IVFRU at 480 min in MCA-tk (p<0.01). Both IVDU and IVFRU uptake were linearly correlated ($R^2>0.96$) with increasing MCA-tk%. Conclusion: The radiolabeld IVDU and IVFRU showed higher specific accumulation in retrovirally HSV1-tk gene transfected Morris hepatoma cell line. Both IVDU and IVFRU could be used as good substrates for evaluation of HSV1-tk gene expression.

• Biomedical Science Letters
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• v.21 no.1
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• pp.40-49
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• 2015

Mesenchymal stem cells (MSCs) have the ability to self-renew and differentiate into multi-lineage cells, thus highlighting the feasibility of using umbilical cord blood-derived MSCs (UCB-MSCs) for cell-therapy and tissueengineering. However, the low numbers of UCB-MSC derived from clinical samples requires that an ex vivo expansion step be implemented. As most stem cells reside in low oxygen tension environments (i.e., hypoxia), we cultured the UCBMSCs under 3% $O_2$ or 21% $O_2$ and the following parameters were examined: proliferation, senescence, differentiation and stem cell specific gene expression. UCB-MSCs cultured under hypoxic conditions expanded to significantly higher levels and showed less senescence compared to UCB-MSCs cultured under normoxic conditions. In regards to differentiation potential, UCB-MSCs cultured under hypoxic and normoxic conditions both underwent similar levels of osteogenesis as determined by ALP and von Kossa assay. Furthermore, UCB-MSCs cultured under hypoxic conditions exhibited higher expression of OCT4, NANOG and SOX2 genes. Moreover, cells expanded under hypoxia maintained a stem cell immnunophenotype as determined by flow cytometry. These results demonstrate that the expansion of human UCB-MSCs under a low oxygen tension microenvironment significantly improved cell proliferation and differentiation. These results demonstrate that hypoxic culture can be rapidly and easily implemented into the clinical-scale expansion process in order to maximize UCB-MSCs yield for application in clinical settings and at the same time reduce culture time while maintaining cell product quality.

• The Journal of Korean Society of Virology
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• v.29 no.4
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• pp.271-281
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• 1999

The nested polymerase chain reaction (PCR) assay was used to determine the sequences of reverse transcriptase (RT) codons 41, 67, 70, 210, 215 and 219 of human immunodeficiency virus-1 (HIV-1) pol gene. Template DNA was obtained from uncultured peripheral blood mononuclear cells from 27 Korean HIV-1 infected patients treated with ZDV and Korean red ginseng. The second PCRs were done for 2 separated regions (RT codons $13{\sim}98$ and $152{\sim}259$) with $5\;{\mu}l$ of the first PCR productNucleotide sequences were determined by direct sequencing. In the 27 patients, CD4+ cell count decreased from $230{\pm}117/{\mu}l$ to $152{\pm}162/{\mu}l$ for $46{\pm}26$ months (Mo), and actual duration of ZDV intake was $72{\pm}16$ Mo. In the 16 patients who had been treated with ZDV therapy ${\ge}25$ Mo, the incidences of 70R, 215F/Y, and 41L were 61%, 28% and 22%, respectively and those of 67N, 210W and 219Q were 17%. The incidences of 215F/Y were 6.7% for group ${\le}12$ Mo treatment, 22.7% for group with 13 to 24 Mo, and 27.8% for group ${\ge}25$ Mo. There was no mutation in 9 patients. It might be associated with the interruption of ZDV therapy for more than 6 months in 6 patients. This study shows that the detection of mutation could be useful prognostic marker with other clinical and virological data, and very low mutation rate is dectected compared to overseas reports.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1134-1146
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• 1998

Background: The tumor suppressor gene p53 is one of the most frequently altered genes in human tumors, including those of the lung. There is now a compelling evidence that wild-type p53 can negatively influence cell growth by causing G1 arrest or by inducing apoptosis. The possibilities of using p53 for gene therapy are also gathering much interest. Material and Method: Our approach towards understanding p53 function would be to study the biological consequences of overexpression of wild-type p53 in normal and tumor cells by using adenovirus vectors capable of giving high levels of the p53 gene product in cells. We have used this vector containing wild-type p53 to infect tumor cells with different p53 status (null, mutant, or wild-type) to confirm that expression of p53 in null or mutant cell lines becomes possible by Adenovirus-p53 transduction, to examine the effects of high levels of p53 expression on the growth properties of tumor cells, to evaluate the role of apoptosis in p53-mediated biological effects, and to examine the effect of Adenovirus-p53 on the tumorigenicities of the lung cancer cell lines in vitro. Result: The results of our study showed that cells expressing endogenous mutant p53 and those devoid of p53 expression altogether were significantly more sensitive to Adenovirus-p53-mediated cytotoxicity compared to tumor cells expressing endogenous wild-type p53 and that overexpression of wild-type p53 induced programmed cell death. Also we knew that Adenovirus-p53 significantly reduced tumor colony formation of human non-small cell lung cancer cell lines, and decreased the growth of pre-formed colonies in vitro. Conclusion: These results suggest that adenovirus is an efficient vector for mediating transfer and expression of tumor suppressor genes in human non-small cell lung cancer cells and that the tumor cells null for p53 or expressing mutant p53 readily undergo apoptosis by Adenovirus-p53.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.20-24
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• 2006

Plasmid DNA (pDNA) is a product of interest for many biopharmaceutical companies and research laboratories, because of increase in the number of gene therapy protocols that use nonviral vectors. This work was undertaken to study the effect of antibiotic and dissolved oxygen concentration (DOC) on the production of a ColE 1-type plasmid (pVAX1-LacZ) hosted in Escherichia coli $DH5\alpha$ and cultured in a batch fermentor with 0.751 of Terrific Broth. A decrease in the DOC from $60\%\;to\;5\%$ was shown to increase the specific pDNA concentration approximately 1.5-fold, due to the downregulation of growth. Additionally, this increase in the pDNA concentration led to a 2.2-fold increase in the purity of cell lysates obtained after cell lysis. However, the use of higher DOC led to 2.8-fold higher volumetric productivity as a consequence of a faster growth rate, reducing the fermentation time from 24 to 8 h. Interestingly, the specific pDNA concentration, and pDNA productivity and purity were always higher $(10-15\%)$ in the absence of antibiotic. Overall, the data indicate that nonselective conditions can be used without compromising yield, productivity, and purity of pDNA.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.29-41
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• 2001

Background : The appearance of multiple-drug-resistant Mycobacterium tuberculosis strains has been seriously compromising successful control of tuberculosis. Rifampin-resistance, caused by mutations in the rpoB gene, can be indicative of multiple-drug-resistance, and its detection is of great importance. The present study aimed to develop an oligonucleotide chip for accurate and convenient screening of drug-resistance. Methods : In order to detect point mutations in the rpoB gene, an oligonucleotide chip was prepared by immobilizing specific probe DNA to a microscopic slide glass by a chemical reaction. The probe DNA that was selected from the 81 bp core region of the rpoB gene was designed to have mutation sites at the center. A total of 17 mutant probes related to rifampin-resistance including 8 rifabutin-sensitive mutant probes were used in this study. For accurate determination, wild type probes were prepared for each mutation position with an equal length, which enabled a direct comparison of the hybridization intensities between the mutant and wild type. Results : Mycobacterial genomic DNA from clinical samples was tested with the oligonucleotide chip and the results were compared with those of the drug-susceptibility test in addition to sequencing and INNO-LiPA Rif. TB kit test in some cases. Out of 15 samples, the oligonucleotide chip results of 13 samples showed good agreement with the rifabutin-sensitivity results. The two samples with conflicting result also showed a discrepancy between the other tests, suggesting such possibilities as existence of mixed strains and difference in drug-sensitivity. Further verification of these samples in addition to more case studies are required before the final evaluation of the oligonucleotide chip can be made. Conlcusion : An oligonucleotide chip was developed for the detection of rpoB gene mutations related to drugsusceptibility. The results to date show the potential for using the oligonucleotide chip for accurate and convenient screening of drug-resistance to provide useful information in antituberculosis drug therapy.