• 생명과학회지
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• 제17권3호통권83호
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• pp.420-426
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• 2007

본 연구에서는 유전자 발현에 중요한 조절 역할을 하는 DNA 메틸화를 식이성 폴리페놀의 하나인 녹차의 대표적인 추출물 EGCG로 억제하였을 때 C2C12 myoblast 세포에 일어나는 현상을 살펴보았다. 그 결과 smooth muscle의 지표인 transgelin, smooth muscle ${\alpha}-actin$ mRNA와 단백질이 현저히 증가함을 보였고, 형태학적으로도 smooth muscle의 전형적인 모습을 보였다. 식이에 포함된 DNA 메틸화 억제제인 EGCG가 C2C12 myoblast를 smooth muscle로 분화를 유도하였으며, 암 예방 차원에서의 EGCG의 역할 외에 혈관질환과 같은 smooth muscle에 관련된 예방과 치료차원에서 EGCG의 역할이 있을 것으로 사료된다. 본 연구는 C2C12 myoblast를 smooth muscle로 유도하는 결정적인 신호전달 역할을 하는 유전자에 대한 연구는 수행하지 못하였다. 따라서 EGCG에 의해 변화되는 유전자에 대한 기전연구가 필요하다고 하겠다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.65.2-65
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• 2003

To protect the plant against several soil-borne pathogens, we are currently constructing disease-resistant transgenic root stock for the growth of cucurbitaceae vegetable plants, watermelon and gourd. We made a watermelon cDNA library from Cladosporium cucumerinum-Infected leaves for substractive hybriazation and differential screening. We isolated the several pathogen inducible cDNA clones, such as caffeoyl-CoA-methyltransferase, LAA induced protein, receptor-like kinase homolog, hydroxyproline-rich glycoprotein, catalase, calmodulin binding protein, mitochondrial ATPase beta subunit, methyl tRNA synthetase and WRKY transcription factors. We previously obtained CaMADS in pepper and galactinol synthase ( CsGolS) in cucumber that were confirmed to be related with disease-resistance. CaMADS and CsGolS2 were transformed into the inbred line 'GO701-2' gourd, the inbred line '6-2-2' watermelon and the Kong-dye watermelon by Agrobacterium tumerfaciens LBA4404. Plant growth regulators (zeatin, BAP and IAA) were used for shoot regeneration and root induction for optimal condition. Putative transgenic plants were selected in medium containing 100mg/L kanamycin and integration of the CaMADS and CsGO/S2 into the genomic DNA were demonstrated by the PCR analysis. We isolated major soil-borne pathogens, such as Monosporascus cannonballus, Didymella bryoniae, Cladosporium cuvumerinum from the cultivation area of watermelon or root stock, and successfully established artificial inoculation method for each pathogen. This work was supported by a grant from BioGreen 21 program, Rural Development Administration, Republic of Korea.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.80.1-80
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• 2003

Several plant and microbial genes that could confer disease resistance in transgenic rice plants are being cloned and characterized. We are currently constructing transgenic rice lines that overexpress the gene products, such as a galactinol synthase, a defensin, and a bacterial ACC deaminase. Subtractive hybridization of a rice cDNA library constructed from the Xanthomonas oryzae-infected ice leaves resulted in isolation of many inducible cDNA clones including a elongation factor EF2, a oryzain alpha, a catalase, a aldehyde dehydrogenase, a S-adenosylmethionine synthetase, a caffeic acid O-methyltransferase, a glyceraldehyde-3-phosphate dehydrogenase, a light-regulated protein, nKY transcription factors, and a nucleotide diphosphate kinase. Some genes among those may be useful genetic sources for construction of disease resistant transgenic rice. Full lengths of the rice OsFIERG and a rice oryzain genomic clones were cloned, and serial deletion fragments of the promoter regions of these genes were fused with GUS reporter gene in pCAMBIA1201, respectively. Promoter activities of these constructs will be examined upon various stresses and Pathogen infections to obtain the pathogen specific inducible-promoter. This work was supported by a grant from BioGreen 21 Program, Rural Development Administration, Republic of Korea.

• Journal of Animal Science and Technology
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• 제53권3호
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• pp.269-274
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• 2011

DNA methyltransferases (DNMTs) are closely associated with the epigenetic change and the gene silencing through the regulation of methylation status in animal genome. But, the role of DNMTs in transgene silencing has remained unclear. So, we examined whether the knockdown of DNMT influences the reactivation of transgene expression in the transgenic quails. In this study, we investigated the expression of DNMT3a, and DNMT3b in blastoderm, quail embryonic fibroblasts (QEFs) and limited embryonic tissues such as gonad, kidney, heart and liver of E6 transgenic quails (TQ2) by RT-PCR. We further analyzed the expression of DNMT3a at different stages of whole embryos during early embryonic development by qRT-PCR. DNMT3a expression was detected in all test samples; however, it showed the highest expression in E6 whole embryo. Embryonic fibroblasts collected from TQ2 quails were treated with two DNMT3a-targeted siRNAs (siDNMT3a-51 and siDNMT3a-88) for RNA interference assay, and changes in expression were then analyzed by qRT-PCR. The siDNMT3a-51 and siDNMT3a-88 reduced 53.34% and 64.64% of DNMT3a expression in TQ2 QEFs, respectively. Subsequently the treatment of each siRNA reactivated enhanced green fluorescent protein (EGFP) expression in TQ2 (224% and 114%). Our results might provide a clue for understanding the DNA methylation mechanism responsible for transgenic animal production and stable transgene expression.

• Reproductive and Developmental Biology
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• 제31권4호
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• pp.241-248
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• 2007

Epigenetic modification dependent DNA methyltransferases (DNMTs) play an important role in tissue- and stage-specific gene regulation and normal mammalian development. In this study, we show that DNMTs are expressed at different levels during hematopoietic stem cell (HSC) differentiation to proerythrocytes. DNMT1, DNMT3A, and DNMT3B were highly expressed at day 7 after differentiation. We used specific siRNA as a tool to probe the relationship between the expression of DNMTs and erythropoietic differentiation. When introduced siRNA of DMNT1 and DMNT3b in human $CD34^+$ cells, these more differentiated into erythrocytes. This was confirmed by glycophorin A (GPA) positive cell analysis and globin gene expression. $GPA^+$ cells increased up to $20{\sim}30%$, and ${\gamma}$- and ${\epsilon}$-globin genes increased in siRNA transfected cells. Therefore, our data suggest that suppression of DNA methylation can affect positively differentiation of HSC and may contribute to expression of erythrocyte lineage genes including GPA and globins.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.33-38
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• 2014

Background: Meningiomas are the second most common primary intracranial tumors after gliomas. Epigenetic biomarkers such as DNA methylation, which is found in many tumors and is thus important in tumorigenesis can help diagnose meningiomas and predict response to adjuvant chemotherapy. We investigated aberrant O6-methyl guanine methyltransferase (MGMT) methylation in meningiomas. Materials and Methods: Sixty-one patients were classified according to the WHO grading, and MGMT promoter methylation status was examined via the methylation-Specific PCR(MSP) method. Results: MGMT promoter methylation was found in 22.2% of grade I, 35% of grade I with atypical features, 36% of grade II, and 42.9% of grade III tumors. Conclusions: There was an increase, albeit not statistically significant, in MGMT methylation with a rise in the tumor grade. Higher methylation levels were also observed in the male gender.

• Journal of Korean Neurosurgical Society
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• 제46권4호
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• pp.385-388
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• 2009

Objective : We analyzed the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter in World Health Organization (WHO) grade III gliomas in association with other molecular markers to evaluate their prevalence. Methods : The samples of a total of 36 newly WHO grade III glioma patients including 19 anaplastic oligodendrogliomas (AO), 7 anaplastic oligoastrocytomas (AOA), and 10 anaplastic astrocytomas (AA) were analyzed. The methylation status of the MGMT gene promoter was confirmed by methylation-specific polymerase chain reaction. The 1p/19q chromosomal deletion status and EGFR amplification were assessed by Fluorescence In-Situ Hybridization. MGMT, EGFR, EGFRvlll, and p53 expression were analyzed by immunohistochemical staining. Results : The MGMT gene promoter was methylated in 32 (88.9%) and unmethylated in 4 (11.2%) Among them, all of the AO and AOA had methylated MGMT gene promoter without exception. Significant associations between MGMT gene promoter hypermethylation and 1p/19q deletion was observed (p=0.003). Other molecular markers failed to show significant associations between MGMT gene promoter statuses. Conclusion : There was extensive epigenetic silencing of MGMT gene in high grade gliomas with oligodendroglial component. Together with frequent 1p/19q co-deletion in oligodendroglial tumors, this may add plausible explanations supporting the relative favorable prognosis in oligodendroglial tumors compared with pure astrocytic tumors.

• BMB Reports
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• 제55권12호
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• pp.595-601
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• 2022

Polycomb Repressive Complex 2 (PRC2) exhibits key roles in mammalian development through its temporospatial repression of gene expression. EZH1 or EZH2 is the catalytic subunit of PRC2 that mediates the mono-, di- and tri-methylation of histone H3 lysine 27 (H3K27me1/2/3), H3K27me2/me3 being a hallmark of facultative heterochromatin. PRC2 is a chromatin-modifying enzyme that is recruited to a limited number of "nucleation sites", spreads H3K27 methylation and fosters chromatin compaction. EZH1 and EZH2 exhibit differences in their expression patterns, levels of histone methyltransferase activity (HMT) in the context of PRC2, and DNA/nucleosome binding activity. This suggests that their roles in heterochromatin formation are disparate. Dysregulation of PRC2 activity leads to aberrant gene expression and is implicated in cancer and developmental diseases. In this review, we discuss the distinct function of PRC2/EZH1 and PRC2/EZH2 in the early and late developmental stages. We then discuss the cancers associated with PRC2/EZH1 and PRC2/EZH2.

• Journal of Cancer Prevention
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• 제22권4호
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• pp.234-240
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• 2017

Background: Lung cancer is the leading cause of cancer-related death worldwide, for which smoking is considered as the primary risk factor. The present study was conducted to determine whether genetic alterations induced by radon exposure are associated with the susceptible risk of lung cancer in never smokers. Methods: To accurately identify mutations within individual tumors, next generation sequencing was conduct for 19 pairs of lung cancer tissue. The associations of germline and somatic variations with radon exposure were visualized using OncoPrint and heatmap graphs. Bioinformatic analysis was performed using various tools. Results: Alterations in several genes were implicated in lung cancer resulting from exposure to radon indoors, namely those in epidermal growth factor receptor (EGFR), tumor protein p53 (TP53), NK2 homeobox 1 (NKX2.1), phosphatase and tensin homolog (PTEN), chromodomain helicase DNA binding protein 7 (CHD7), discoidin domain receptor tyrosine kinase 2 (DDR2), lysine methyltransferase 2C (MLL3), chromodomain helicase DNA binding protein 5 (CHD5), FAT atypical cadherin 1 (FAT1), and dual specificity phosphatase 27 (putative) (DUSP27). Conclusions: While these genes might regulate the carcinogenic pathways of radioactivity, further analysis is needed to determine whether the genes are indeed completely responsible for causing lung cancer in never smokers exposed to residential radon.

• Journal of Plant Biotechnology
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• 제36권1호
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• pp.23-29
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• 2009

벼의 저온처리 cDNA 은행에서 분리된 CCCH 형태 zinc finger 단백질인 OsZF2의 기능을 분석하기 위하여 벼에서 CaMV 35S 프로모터 조절하에 OsZF2가 발현(35S:OsZF2)되는 형질전환벼 식물체를 개발하였다. 35S:OsZF2 형질전환벼에 대한 하이그로 마이신저항성 검정을 통해 동형접합체 계통을 선발하고 Northern 발현분석에 의해 OsZF2 유전자가 형질전환체에서 과발현되는 것을 확인하였다. 형질전환체와 대조구인 낙동벼를 100 mM NaCl 첨가 MS 배지에서 키운 후 잎과 뿌리의 길이를 측정하여 내염성 검정을 수행한 결과 대조구에 비해 형질전환체 생육이 다소 양호 한 것으로 나타났다. GMO 포장에서 생육상태를 관찰 한 결과 형질전환체는 생육지연으로 인한 왜화 현상을 나타내며 출수기 또한 열흘 정도 지연되나 등숙기에는 대조구와 같은 초장을 보였다. zinc finger 유전자는 식물체의 발달과 분화 단계 및 환경 스트레스 반응 등 중요한 역할을 하는 것으로 알려져 있으므로 유전체발현 분석으로 하위단계에서 조절되는 유전자 발현 양상을 분석하였다. 35S:OsZF2 전환체에서 낙동벼보다 4배 이상 발현이 증가된 유전자 중에서 게놈 주석에 기초한 기능을 유추하면 신호전달과 관련된 protein kinase, DNA 결합단백질과 대사에 관련된 효소 유전자, 스트레스 반응에 관여하는 일부 유전자 및 병 저항성과 관련된 유전자들의 발현이 증가되었다. 따라서 벼에서 분리된 OsZF2 CCCH type zinc finger 유전자는 벼 성장 발달과 스트레스에 반응하는 상위 조절자로서 기능을 할 것으로 추측된다.