• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.21-29
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• 2017

Methylation of CpG islands in the promoter region of genes acts as a significant mechanism of epigenetic gene silencing in head and neck squamous cell carcinoma (HNSCC). DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable mark. In the present study, we assessed the genome-wide preliminary screening and were to identify novel methylation biomarker candidate in HNSCC. Genome-wide methylation analysis was performed on 10 HNSCC tumors using the Methylated DNA Isolation Assay (MeDIA) CpG island microarray. Validation was done using immunohistochemistry using tissue microarray of 135 independent HNSCC tumors. In addition, in vitro proliferation, migration/invasion assays, RT-PCR and immunoblotting were performed to elucidate molecular regulating mechanisms. Our preliminary validation using CpG microarray data set, immunohisto-chemistry for HNSCC tumor tissues and in vitro functional assays revealed that methylation of the Homeobox B5 (HOXB5) and H6 Family Homeobox 2 (HMX2) could be possible novel methylation biomarkers in HNSCC.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.203-211
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• 2008

Rapid detection-method for Shiga toxin type 1 that was produced from Shiga toxin-producing Escherichia coli (STEC) was developed by two-step ultra-rapid real-time (URRT) PCR. The specific primers were deduced from 80 bp stable region of stx type 1 (stxl) gene among various informations of STEC strains. URRT PCR is a microchip-based real-time PCR using 6 ${\mu}l$ of reaction volume with extremely short denaturation step and annealing/extension step (1 sec, 3 sec, respectively) in each cycle of PCR. Using the stx1-specific URRT PCR, 35 cycled PCR were finished in time of 6 min and 38 see, also measured 7 min and 28 see including melting temperature (Tm) analysis. The detection-limit of stxl-specific URRT-PCR was estimated until 3 colony forming units / PCR with products with stable Tm at $81.42{\pm}0.34^{\circ}C$. In the applications to various STEC strains and contaminated genomic DNAs, stx1-specific URRT-PCR were tested and shown that it would be expected an useful method for the rapid detection of stx1-coded STEC strains.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.202-208
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• 1997

In this study, we evaluated the use of RAPD method to discriminate among strains of Fusarium species including F. oxysporum and f. sp. of F. oxysporum. As a result of the amplication, fifteen primers showed total 180 bands ranging from 0.2 to 3 Kb. Among those 180 bands, 126 polymorphic bands were used for bionominal matrix code (0, 1), and UPGMA dendrogram analysis. Fusarium oxysporum isolate 355 showed high similarity with F. oxysporum isolate 358 at 0.9603. Fusarium roseum isolate 87 and F. oxysporum isolate 358, F. o. f. sp. lycopersici isolate 69 and F. o. f. sp. melongena 68 showed low similarity of 0.3809. Fusarium oxysporum isolate 361 and F. o. f. sp. raphani isolate 218 showed similarity of 0.8730, F. oxysoprum isolate 354 and unidentified Fusarium sp. isolate 228 showed similarity matrix of 0.7936, and F. roseum isolate 87 and F. o. f. sp. raphani isolate 57 showed similarity matrix of 0.5873.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.84-89
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• 2005

Phosphomannomutase (PMM) is a key enzyme in prokaryotes and eukaryotes, which catalyzes the conversion of ${\alpha}$-D-mannose 6-phosphate to ${\alpha}$-D-mannose 1-phosphate. The latter is the substrate for the synthesis of GDP-mannose, which serves as the mannosyl donor for many metabolic pathways in the cells. We report here on the isolation of a gene from a genomic library of Sphingomonas chungbukensis DJ77, the pmmC gene encoding phosphomannomutase. The gene was cloned into E. coli expression vector, and the sequence was analyzed. The ribosomal binding site GGAAG lays 5 bp upstream of the ORF of 750 bp, which is initiated by ATG codon and terminated by TAG. The predicted sequence of the enzyme consists of 249 amino acids with a molecular mass of 27.4 kDa and showed $86.9\%$ similarity to that of eukaryotic phosphomannomutase after bioinformatical analyses with the conserved domain search of NCBI. The purified gene product revealed the activity of phosphomannomutase. In conclusion, we confirmed that pmmC gene encodes phosphomannomutase actually.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.59-65
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• 2013

The jujube is an important fruit tree species in Korea. Traditionally, classifications of jujube cultivars have been based on morphological characters; however, morphological identification can be problematic because morphological traits are affected by environmental conditions. Therefore, DNA markers are now being used for the rapid and accurate identification of plant species. Inter-simple sequence repeat (I-SSR) is one of the best DNA-based molecular marker techniques, which is useful for studying genetic relations and for the identification of closely related cultivars. In this study, 5 Korean jujube trees and 1 jujube tree imported from China were analyzed for 16 I-SSR primers. Amplification of the genomic DNA of jujube cultivars by using I-SSR analysis generated 100 bands, with an average of 6.25 bands per primer, of which 45 bands (45%) were polymorphic. The number of amplified fragments with I-SSR primers ranged from 2 to 13. The percentage of polymorphism ranged from 10% to 100%. I-SSR finger printing profiles showed that 'Boeun jujube' and 'Daeri jujube' had characteristic DNA patterns, indicating unequivocal cultivar identification at molecular level. According to the results of clustering analysis, the genetic similarity coefficient ranged from 0.68 to 0.92. 'Boeun jujube' and 'Daeri jujube' were divided into independent groups, and 'Bokjo jujube', 'Geumseong jujube', 'Wolchul jujube', and 'Mudeung jujube' were placed in the same group. Therefore, I-SSR markers are suitable for the discrimination of 'Boeun jujube' and 'Daeri jujube' cultivars.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.66-74
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• 2018

Background: Tumor response to anticancer therapies can much be influenced by microenvironmental factors. In this study, we determined the effect of these microenvironmental factors on DNA methylation using A549 human lung adenocarcinoma cell line. Materials and Methods: We subjected A549 cells to various conditions mimicking tumor microenvironment including hypoxia, acidosis (sodium lactate), oxidative stress ($H_2O_2$), bystander effect (supernatant from doxorubicin (Dox)-treated or irradiated cells), and immune cell infiltration (supernatant from THP-1 or Jurkat T cells). Genomic DNA was isolated from these cells and analyzed for DNA methylation. Clonogenic cell survival, gene expression, and metabolism were analyzed in cells treated with some of these conditions. Results and Discussion: We found that DNA methylation level was significantly decreased in A549 cells treated with conditioned media from Dox-treated cells or Jurkat T cells, or sodium lactate, indicating an active transcription. To determine whether the decreased DNA methylation affects radiation sensitivity, we exposed cells to these conditions followed by 6 Gy irradiation and found that cell survival was significantly increased by sodium lactate while it was decreased by conditioned media from Dox-treated cells. We further observed that cells treated with conditioned media from Dox-treated cells exhibited significant changes in expression of genes including BAX and FAS (involved in apoptosis), NADPH dehydrogenase (mitochondria), EGFR (cellular survival) and RAD51 (DNA damage repair) while sodium lactate increased cellular metabolism rather than changing the gene expression. Conclusion: Our results suggest that various tumor microenvironmental factors can differentially influence DNA methylation and hence radiosensitivity and gene expression in A549 cancer cells.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.114-120
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• 2017

Lentinula edodes is an edible mushroom that is mainly cultivated in Asian countries. Recently, new cultivars of this mushroom have been developed in Korea; variety protection is very important, so the development of efficient molecular markers that can distinguish each variety is required. In this study, we developed cleaved amplified polymorphic sequence (CAPS) markers for the identification of L. edodes cultivars (Sanmaru 1ho and Chunjang 3ho). These markers were developed from whole genomic sequencing data from L. edodes monokaryon strain B17 and resequencing data from 10 dikaryon strains. A single nucleotide polymorphism changed in scaffold 9 POS 1630048 in Sanmaru 1ho($G{\rightarrow}T$), and in scaffold 13 POS 920681 in Chunjang 3ho ($G{\rightarrow}A$). The restriction enzymes TspR I and Xho I distinguished Sanmaru 1ho and Chunjang 3ho, respectively, from other strains. Thus, we developed 2 CAPS markers for the identification of the L. edodes cultivars Sanmaru 1ho and Chunjang 3ho.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.299-314
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• 2011

The choice of molecular markers is the first step when selecting experimental plans in the field of population genetics. The popular molecular markers in population genetic studies are mainly allozyme, RAPD, RFLP, AFLP, microsatellite, SNP and ISSR. Among these, microsatellites are frequently found in nuclear, chloroplast and mitochondrial genome, showing a high level of polymorphism and nuclear microsatellites are codominant. Thus, it is a favorable molecular marker for population structure analyses and genetic diversity studies. Microsatellites are composed of tandem repeated 1~6 base pair nucleotide motifs and can be easily amplified by PCR reactions using locus specific primers. Because microsatellites have low cross-species transferability, however, they are only applicable between phylogenetically close species. In wild plants, the lack of genomic information and the high development cost of the microsatellite obstruct the wider use of microsatellites in plant population genetics research. In this review, we introduce the basis for microsatellite markers, the development process, and analytical methods as well as evolutionary models and their applications. In addition, possible genotyping errors which lead to erroneous conclusions are discussed.

• Journal of Acupuncture Research
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• v.22 no.2
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• pp.1-12
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• 2005

Objective: With the onset of stroke, white blood cells release several proinflammatory cytokines, including interleukin (IL)-6, IL-10, and tumor necrosis factor $(TNF)-{\alpha}$. It has been proven in previous studies that the release of these cytokines is related to the extent of damage to the brain and to overall prognosis. However, no studies have yet been performed to determine the connection with IL-6 and IL-10. Thus, this study is performed to see whether polymorphisms of IL-6, IL-10, and $TNF-{\alpha}$ genes that show increased serum concentration with the onset of stroke are related to stroke attack in Koreans. Methods : Peripheral blood samples derived from patients with stroke (n=100) and healthy controls (n=100) were taken under informed consent. In subjects with stroke, blood samples were obtained within 24 hours of stroke onset. Genomic DNA was isolated using the Wizard DNA Purification Kit (Promega, Madison, WI). Results : 1. Subjects with Heterozygote (GA) and Homozygote (AA) $TNF-{\alpha}$ gene types showed 2.433 and 20.457 times higher risks of being attacked by stroke, respectively, compared to subjects with wild type (GG) $TNF-{\alpha}$ gene type. The data was still statistically significant after adjusting for age, sex, history of smoking, and history of alcohol drinking. 2. Subjects with Homozygote (CC) IL-6 gene type showed 182.033 times higher risk of being attacked by stroke, compared to subjects with wild type (GG) IL-6 genes. This data was statistically insignificant (p=0.700). The data was still statistically insignificant after adjusting for age, sex, history of smoking, and history of alcohol drinking. 3. Subjects with Heterozygote (GA) and Homozygote (GG) IL-10 gene types showed 8.785 and 3.303 times higher risks of being attacked by stroke, respectively, compared to subjects with wild type (AA) IL-10 genes. The data was still statistically insignificant after adjusting for age, sex, history of smoking, and history of alcohol drinking. Conclusion : Our results suggest that the investigated $TNF-{\alpha}$ and IL-10 gene polymorphisms play an important role in stroke attack, but IL-6 gene polymorphism has not been found to associated with stroke.

• Korean Journal of Clinical Pharmacy
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• v.24 no.4
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• pp.231-239
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• 2014

Background and objective: Pravastatin has been shown to have favorable risk-benefit profile when it is administered to hypercholesterolemic subjects to prevent cardiovascular events. However, subjects with impaired OATP1B1 activity may be more susceptible to pravastatin-induced muscle toxicity than subjects with normal OATP1B1 activity. A systematic review was conducted to evaluate the effect of SLCO1B1 genetic polymorphism on pharmacokinetics of pravastatin. Method: Medline$^{(R)}$ and Embase$^{(R)}$ were searched for relevant studies until July 2013. The search terms used were pravastatin AND (SLCO1B1 OR OATP1B1 OR LST1 OR SLC21A6) AND (gene OR $genetic^*$ OR $genomic^*$ OR $pharmacogenet^*$ OR $pharmacogenom^*$ OR $polymorph^*$). Results: A meta-analysis of the area under the concentration-time curve (AUC) of pravastatin in $SLCO1B1^*15$ and $SLCO1B1^*1a/^*1a$ was conducted. Five studies met all the inclusion criteria and methodological requirements. There was no statistically significant difference in the AUC value between $SLCO1B1^*15$ and $SLCO1B1^*1a/^*1a$ (p=0.728). However, $SLCO1B1^*15$ participants exhibited significantly higher AUC values than $SLCO1B1^*1b/^*1b$ carriers (p<0.001). In case of $SLCO1B1^*15^*15$ carriers, they had significantly higher AUC value than $SLCO1B1^*1a/^*1a$ subjects (p=0.002). Lastly, compared with to the subjects of $SLCO1B1^*1a/^*1a$, the carriers of heterozygous $SLCO1B1^*15$ increased the AUC value of pravastatin statistically significantly in Asian population (p=0.014). Conclusion: The present meta-analysis suggests that subjects with $SLCO1B1^*15$ are associated with increased AUC of pravastatin.