• Journal of Environmental Science International
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• v.14 no.7
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• pp.649-655
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• 2005

Microcystis aeruginosa is common form of cyanobacteria (blue-green algae) capable of producing toxic heptapeptide (microcystin) that cause illness or death. The comparison of molecular genetic method with the morphological characteristics of cyanobacteria was conducted. We have designed PCR primers (JJM98F, JJM1141R) for cyanobacterial 16S rRNA and phycocyanin intergenic spacer (PC-IGS) gene domain. To confirm the production of microcystins, PCR primers for the N-methyltransferase (NMT) domain of microcystin synthetase gene mcyA were designed using 21 cyanobacteria strains Most of isolated strains from the Nakdong River was classified as Microcystis aeruginosa and the similarities were $99\%$ with M. aeruginosa AF 139292. $38.1\%$ of isolated strains contained microcystin synthesis gene. NMT (N-methyltransferase) were not detected in isolated strain in several strains, which means non-toxic. However, the NMTs of the strains were detected during the cultivation.

• Animal cells and systems
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• v.16 no.4
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• pp.289-294
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• 2012

Histone methylation has diverse functions including transcriptional regulation via its lysine or arginine residue methylation. Studies indicate that deregulation of histone methylation is linked to human cancers including leukemia. Histone H3K27 methyltrnasferase response element II binding protein (RE-IIBP), as a transcriptional repressor to target gene IL-5, interacts with HDAC and is over-expressed in leukemia patient samples. In this study, we have identified that hematopoiesis-related genes GATA1 and HOXA9 are down-regulated by RE-IIBP in K562 and 293T cells. Transient reporter analysis revealed that GATA1 transcription was repressed by RE-IIBP. On the other hand, HOXA9 and PBX-related homeobox gene MEIS1 was up-regulated by RE-IIBP. These results suggest that RE-IIBP might have a role in hematopoiesis or leukemogenesis by regulating the transcription of target genes, possibly via its H3K27 methyltransferase activity.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.69-77
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• 2020

The tumor suppressor gene, p53, is inactivated in the human hepatocellular carcinoma cells line, Hep3B. Berberine has been reported to inhibit the proliferation of cancer cells. This study examined whether apoptosis was induced in berberine-treated Hep3B cells and observed the association between apoptosis and the expression of p53 and DNA methyltransferase (DNMT). The cell viability was measured using an MTT assay. Apoptosis of Hep3B was measured using annexin V flow cytometry. Berberine-treated cells were examined for their DNMT enzymatic activity, mRNA expression, and protein synthesis. The p53 levels were examined by Western blot analysis. The berberine treatment resulted in increased Hep3B cell death and apoptosis in a time- and dose-dependent manner. The DNMT3b activity, mRNA expression, and protein levels all decreased after the berberine treatment. In contrast, the p53 protein levels increased with a concomitant decrease in DNMT3b. No change in the expression of ERK was observed, but the P-ERK levels decreased in a dose dependent manner. These results indicate that a treatment of Hep3B cells with berberine can reduce the expression of DNMT3b, leading to an increase in the tumor suppressant gene p53 and an increase in cell apoptosis. This shows that berberine can effectively suppress the proliferation of liver cancer cells.

• Journal of Life Science
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• v.18 no.4
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• pp.580-584
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• 2008

$O^6-methylguanine-DNA$ methyltransferase (MGMT) is a DNA repair protein that protects cells against the carcinogenic effects of alkylating agents. The loss of MGMT expression was commonly known due to hypermethylation of CpG islands in its promoter region. We evaluated the expression of MGMT by immunohistochemistry in order to examine the relationship between loss of MGMT expression and clinicopathological characteristics in 74 Korean patients with non-small cell lung cancers. Loss of MGMT was detected in 25 (33.8%) of 74 cases. The loss of MGMT expression was frequently seen in the adenocarcinoma than in the squamous cell carcinoma (p=0.021). However, there was no significant differences between loss of MGMT expression and other clinicopathological characteristics, including age, gender, smoking status, tumor size, tumor T stage, and lymph node metastasis (p>0.05). In conclusion, loss of MGMT expression was related with the histologic type of lung cancer. Further methylation study of MGMT promoter is needed to evaluate the relationships with immunohistochemical expression of MGMT and to clarify the role of MGMT in lung cancer.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.84-84
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• 2003

DNA methylation is involved in epigenetic processes such as X-chromosome inactivation, imprinting and silencing of transposons. DNA methylation is a highly plastic and critical component of mammalian development The DNA methyltransferases (Dnmts) are responsible for the generation of genomic methylation patterns, which lead to transcriptional silencing. The maintenance DNA methyltransferase enzyme, Dnmt 1, and the de novo methyltransferase, Dnmt3a and Dnmt3b, are indispensable for development because mice homozygous for the targeted disruption of any of these genes are not viable. The occurrence of DNA methylation is not random, and it can result in gene silencing The mechanisms underlying these processes are poorly understood. It is well established that DNA methylation and histone deacetylation operate along a common mechanistic pathway to repress transcription through the action of methyl-binding domain proteins (MBDs), which are components of, or recruit, histone deacetylase (HDAC) complexes to methylated DNA. As a basis for future studies on the role of the DNA-methyl-transferase in porcine development, we have isolated and characterized a partial cDNA coding for the porcine Dnmt1. Total RNA of testis, lung and ovary was isolated with TRlzol according to the manufacture's specifications. 5 ug of total RNA was reverse transcribed with Super Script II in the presence of porcine Dnmt 1 specific primers. Standard PCRs were performed in a total volume of 50 ul with cDNA as template. Two DNA fragmenets in different position were produced about 700bp, 1500bp and were cloned into pCR II-TOPO according to the manufacture's specification. Assembly of all sequences resulted in a cDNA from 158bp of 5'to 4861bp of 3'compare with the known human maintenance methyltransferase. Now, we are cloning the unknown Dnmt 1 region by 5'-RACE method and expression of Dnmt 1 in tissues from adult porcine animals.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.518-518
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.987-987
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• 2005

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.111-115
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• 2001

An association study with Korean alcoholic patients(n=50) and normal controls(n=53) was performed to find the relationship between catechol-O-methyltransferase(COMT) gene polymorphism and alcoholism using polymerase chain reaction-restriction fragment length polymorphism. When we compared the allele and genotype frequencies of Nla III COMT gene polymorphism in alcoholism and normal controls, there was no significant difference between two groups. Our results do not support an association between the Nla III polymorphism of COMT gene and alcoholism.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.131-134
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• 2001

In $\lambda$-Zap II vector system, a cDNA library was constructed for the developing secondary xylem mRNA from hybrid poplar, Populus nigra x maximowiczii. A cDNA clone of 1.5 kb in size, pOMTB1.4 encoding a lignin-bispecific O-methyltransferase was screened by plaque hybridization using a probe of 540 bp cDNA amplified by polymerase chain reaction from the cDNA library and identified by nucleotide sequencing. Its nucleotide sequence contains one open reading frame of 366 amino acids. The deduced amino acid sequence in comparison with that of Populus tremuloides showed the differences of 9 amino acids and revealed 85-99% homology among alfalfa, poplar and aspen.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.491-494
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• 2009

Within the secondary metabolite class of flavonoids, which consist of more than 10,000 known structures, flavones define one of the largest subgroups. The diverse function of flavones in plants as well as their various roles in the interaction with other organisms offers many potential applications including in human nutrition and pharmacology. We used two genes, flavone synthase (PFNS-l) that converts naringenin into apigenin and flavone 7-O-methyltransferase (POMT-7) that converts apigenin into 7-O-methyl apigenin, to synthesize 7-O-methyl apigenenin from naringenin. The PFNS-l gene was subcloned into the E. coli expression vector pGEX and POMT-7 was subcloned into the pRSF vector. Since both constructs contain different replication origins and selection markers, they were cotransformed into E. coli. Using E. coli transformants harboring both PFNS-l and POMT-7, naringenin could be converted into 7-O-methyl apigenin, genkwanin.