• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9955-9960
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• 2014

Background: Promoter hypermethylation is a common event in human cancer. O6-methylguanine-DNA methyltransferase (MGMT) is a gene involved in DNA repair, which is methylated in a variety of cancers. We aimed to explore the methylation status of MGMT gene among the North Eastern population where esophageal cancer incidence and exposure to carcinogens like nitrosamines is high. Materials and Methods: A total of 100 newly diagnosed esophageal cancer cases along with equal number of age, sex and ethnicity matched controls were included in this study. Methylation specific PCR was used to determine the MGMT methylation status in serum samples. Results: Aberrant promoter methylation of the MGMT gene was detected in 70% of esophageal cancer cases. Hypermethylation of MGMT gene was found to be influenced by environmental factors like betel quid and tobacco which contain potent carcinogens like nitrosamines. Tobacco chewing and tobacco smoking habit synergistically with MGMT methylation elevated the risk for esophageal cancer development [adjusted OR=5.02, 95% CI=1.35-18.74; p=0.010 for tobacco chewing and Adjusted OR=3.00, 95% CI=1.22-7.36; p=0.014 for tobacco smoking]. Conclusions: Results suggest that the DNA hypermethylation of MGMT is an important mechanism for MGMT gene silencing resulting in esophageal cancer development and is influenced by the environmental factors. Thus MGMT hypermethylation can be used as a biomarker for esophageal cancer in high incidence region of North East India.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.585-591
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• 2001

To compare the p10 promoter activity of Bombyx mori nucleopolyhedrovirus (BmNPV)K1 and K4, recombinant viruses Bm101-LacZ and Bm104-LacZ with a lacZ gene under the control of each p10 promoter were constructed. The $\beta$-galactosidase activity due to Bm101-LacZ was about 5.5- and 1.1-fold higher than that due to Bm104-LacZ and BmK1-LacZ, respectively. expressing ${\beta}$-galactosidase under the control of a polyhedrin promoter. The recombinant virus BmK1-104LacZ with the same genome structure as Bm101-LacZ, except for a p10 promoter region, produced a similar ${\beta}$-galactosidase activity to that due to Bm104-LacZ and 5.5-fold lower than that due to Bm101-LacZ. The virus yield, expression level of polyhedrin, and polyhedra productivity for each recombinant virus was almost similar. These results suggested that the difference in the expression level of ${\beta}$-galactosidase resulted from a difference in the p10 promoter regions, and that an expression vector using the p10 promoter of BmNPV-K1 could be usefully exploited in the mass production of foreign proteins with silkworm larvae by means of oral ingestion.

• Genomics & Informatics
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• 제10권3호
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• pp.167-174
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• 2012

AKT is a signal transduction protein that plays a central role in the tumorigenesis. There are 3 mammalian isoforms of this serine/threonine protein kinase-AKT1, AKT2, and AKT3-showing a broad tissue distribution. We first discovered 2 novel polymorphisms (AKT2 -9826 C/G and AKT3 -811 A/G), and we confirmed 6 known polymorphisms (AKT2 -9473 C/T, AKT2 -9151 C/T, AKT2 -9025 C/T, AKT2 -8618G/A, AKT3 -675 A/-, and AKT3 -244 C/T) of the AKT2 and AKT3 promoter region in 24 blood samples of Korean lung cancer patients using direct sequencing. To evaluate the role of AKT2 and AKT3 polymorphisms in the risk of Korean lung cancer, genotypes of the AKT2 and AKT3 polymorphisms (AKT2 -9826 C/G, AKT2 -9473 C/T, AKT2 -9151 C/T, AKT2 -9025 C/T, AKT2 -8618G/A, and AKT3 -675 A/-) were determined in 360 lung cancer patients and 360 normal controls. Statistical analyses revealed that the genotypes and haplotypes in the AKT2 and AKT3 promoter regions were not significantly associated with the risk of lung cancer in the Korean population. These results suggest that polymorphisms of the AKT2 and AKT3 promoter regions do not contribute to the genetic susceptibility to lung cancer in the Korean population.

• Mycobiology
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• 제46권4호
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• pp.429-439
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• 2018

To develop a convenient promoter analysis system for fungi, a null-pigment mutant (NPG) of Aspergillus nidulans was used with the 4'-phosphopantetheinyl transferase (PPTase) gene, npgA, which restores the normal pigmentation in A. nidulans, as a new reporter gene. The functional organization of serially deleted promoter regions of the A. nidulans trpC gene and the Cryphonectria parasitica crp gene in filamentous fungi was representatively investigated to establish a novel fungal promoter assay system that depends on color complementation of the NPG mutant with the PPTase npgA gene. Several promoter regions of the trpC and crp genes were fused to the npgA gene containing the 1,034-bp open reading frame and the 966-bp 3' downstream region from the TAA, and the constructed fusions were introduced into the NPG mutant in A. nidulans to evaluate color recovery due to the transcriptional activity of the sequence elements. Serial deletion of the trpC and crp promoter regions in this PPTase reporter assay system reaffirmed results in previous reports by using the fungal transformation step without a laborious verification process. This approach suggests a more rapid and convenient system than conventional analyses for fungal gene expression studies.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.563-573
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• 2007

Genetic polymorphisms associated with aggressive periodontitis have previously been reported. Interleukin-10 is an immunoregulatory cytokine that plays a role in the pathogenesis of periodontitis. Individual capacity for IL-10 production appears to be under genetic influence, The aim of present investigation was to explore possible genetic association of IL-10 gene promoter polymorphisms with generalized aggressive periodontitis. The study population consisted of 37 generalized aggressive periodontitis patients from the Department of Periodontology, Chonnam National University Hospital and 27 control subjects, all the subjects were non-smokers, Genomic DNA was obtained from buccal swab. The IL-10promoter -597, -824, -1082 positions were genotyped by amplifying the polymorphic regions using polymerase chain reaction (PCR) , followed by restriction enzyme digestion and gel electrophoresis. IL-10-597 C (allele 1) to A (allele 2) and IL-10-824 C (allele 1) to T (allele 2) and IL-10-1082 G (allele 1) to A (allele 2) polymorphisms were examined. The results were as follows. 1. In patients, the distribution of genotypes C/C, C/A and NA at Il-10-597 was determined to be 13.5%, 37.8% and 48.7%, respectively and the distribution of genotypes at IL-10-824 was the same as that of IL-10-597. The distribution of genotypes G/G, G/A and NA at IL-10-1082 was found to be 2.7%, 16.2% and 81. 4%, respectively. No statistical difference in genotype distribution was found between the patient and control groups. 2. Allele 2 carriage rate at the three position of the IL-10 promoter region was higher in the control group than the patient group. 3. Allele 2 frequencies at IL-10-597 and -824 positions were higher in female group than male group and its difference was statistically significant(p<0.05). No significant difference in genotype distribution between the control and patient groups. Allele frequency between control and patient groups was not significantly different although allele 2 frequency at the three positions in the IL-10 promoter region appeared to be higher in control group. In conclusion, no clear association between IL-10 gene promoter polymorphisms and generalized aggressive periodontitis in Korean was observed.

• Plant Biotechnology Reports
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• 제3권4호
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• pp.325-331
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• 2009

To efficiently express a gene of interest in transgenic plants, the choice of promoter is a crucial factor as it directly affects the expression of the transgene that will yield the desired phenotype. The Arabidopsis ${\beta}-carotene$ hydroxylase 1 gene (AtBch1) shows constitutive and ubiquitous expression and was thus selected as one of best candidates for constitutive promoter analysis by both in silico northern blotting and semi-quantitative RT-PCR analysis. To investigate AtBch1 promoter activity, the 1,981-bp 5'-upstream region of this gene was fused with ${\beta}-glucuronidase$ (GUS) and transformed into Arabidopsis. Through the molecular characterization of transgenic leaf tissues, the AtBch1 promoter generated strong activity that drives 1.8- and 2-fold higher GUS expression than the cauliflower mosaic virus 35S (35S) promoter at the transcriptional and translational levels, respectively. Furthermore, the GUS enzyme activity driven by the AtBch1 promoter was 2.8-fold higher than that produced by the 35S promoter. By histochemical GUS staining, the ubiquitous expression of the AtBch1 promoter was observed in all tissues of Arabidopsis. Semi-quantitative RT-PCR analysis with different tissues further showed that this promoter serves as a strong constitutive driver of transgene expression in dicot plants.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.371-376
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• 2012

Background: Caveolin-1 (CAV-1), encoding the structural component of cellular caveolae, is a suggested tumor suppressor gene involved in cell signalling. Aberrant promoter methylation of CAV-1 is associated with inactivation of expression. We previously observed CAV-1 mutations in breast cancers and therefore devised this study to examine the hypermethylation status of the promoter region of CAV-1 with reference to breast cancer progression and development. Methods: Hypermethylation status of CAV-1 was analyzed by methylation specific PCR. Loss of expression of the CAV-1 gene was further evaluated by semi-quantitative rt-PCR. Results: 28/130 (21.5%) breast cancer cases showed promoter hypermethylation with reduced CAV-1 expression levels when compared with adjacent normal breast tissue. CAV-1 gene hypermethylation was significantly related to menopausal status, histopathological grade and age. Conclusion: The rationale of our study is that CAV-1 gene is transcriptionally repressed in breast cancer cells due to hypermethylation. Our results reveal that promoter hypermethylation and loss of expression of the CAV-1 gene is an important alternative mechanism for inactivation of CAV-1 leading to complete gene silencing.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.240-245
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• 1991

We have constructed a promoter-probe vector pKU20 using pKT230, a derivative of broad-host-range plsmid RSF1010, as a base. The pKU20 contains structural gene for aminoglycoside phos-photransferase (aph), without promoter, and a multiple cloning site upstream the aph. Using this vector, a 412base pairs (bp) PstI fragment showing strong promoter activity both in Escherichia coli LE392 and Pseudomonas putida KCTC1644 has been cloned from Pseudomonas fluorescens chromosomal DNA on the basis of streptomycin resistance. The nucleotide sequence of the 412 bp fragment has been determined and the putative - 35 and -10 region was observed. Insecticidal protein gene of Bacillus thuringiensis subsp. kurstaki HD-73 inserted on downstream of the promoterlike DNA fragment was efficiently expressed in E. coli and P. putida. The toxin protein was efficiently synthesized in an insoluble form in both strains.

• 생명과학회지
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• 제15권2호
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• pp.176-181
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• 2005

Calmodulin 유전자의 발현 조절을 연구하기 위해, 벼 calmodulin promoter (RCaM-2)를 분리하여 GUS (report 유전자)에 융합하였다. GUS 활성은 정단조직, 근단 및 관다발 영역과 같은 성장조직에서 높게 발현되었다. 줄기와 페티올의 transverse 절단부위 GUS 활성은 관다발계의 안쪽에 제한되었으며 관다발계의 외부에 위치한 피층과 표피에서는 강하게 발현된 식물에서도 GUS 활성이 나타나지 않았다. GUS 활성은 어린 조직에서 특이적으로 발현되었으며 상처에 의해서 신속하게 증가하였다. RCaM-2 promoter는 세포분열이 왕성한 어린조직이나 생장점에서 강하게 발현되며 mechanical 신호에 의해서 현저히 유도되었다. 이러한 결과는 RCaM-2 유전자의 5'-flanking 영역이 상처에 의해서 유도되는 발현을 조절하는 것으로 추정된다.

• 생명과학회지
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• 제17권5호
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• pp.714-718
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• 2007

유전자의 구조 예측 및 발현 기작에 대한 연구는 매우 중요한 사안으로 대두되고 있다. 특히 유전자 발현 제어에 중요한 역할을 하는 프로모터 영역을 예측하는 것은 전체 생명체 네트워크 규명을 위한 단초를 제공하기 때문에 많은 연구가 이루어지고 있다. 본 논문에서는 이러한 진핵생물의 유전자 프로모터 예측을 위한 Support Vector Machine(SVM) 활용방안에 대한 연구내용을 다루고 있다. 특성 벡터 값 생성을 위한 인코딩 방법 및 학습 데이터들의 구성에 대한 다양한 실험을 통해 SVM활용 방안에 대한 올바른 방향을 제시하고 있다.