• Title/Summary/Keyword: demethylation

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Overexpression of NtROS2a gene encoding cytosine DNA demethylation enhances drought tolerance in transgenic rice (시토신 탈메틸화 관련 NtROS2a 유전자 도입 형질전환벼의 건조스트레스 내성 증진)

  • Choi, Jang Sun;Lee, In Hye;Cho, Yong-Gu;Jung, Yu Jin;Kang, Kwon Kyoo
    • Journal of Plant Biotechnology
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    • v.43 no.3
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    • pp.376-382
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    • 2016
  • DNA methylation regulations gene expression, thus having pivotal roles in a myriad of physiological and pathological processes. In this study, the morphology and stress tolerance of transgenic rice overexpressing NtROS2a were determined. Transgenic plants exhibited less and shorter lateral shoots. Under various treatments, rice overexpressing NtROS2a showed alleviation of damage symptoms with higher survival rate. After drought and re-watering treatment, transgenic rice seedlings restored their normal growth. However, wild type plants could not be rescued. These findings indicate that overexpression of NtROS2a gene in rice seedlings can increase their tolerance to drought stresses.

Relationship between Cancer Stem Cell Marker CD133 and Cancer Germline Antigen Genes in NCI-H292 Lung Cancer Cells

  • Ko, Taek Yong;Kim, Jong In;Lee, Sang Ho
    • Journal of Chest Surgery
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    • v.53 no.1
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    • pp.22-27
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    • 2020
  • Background: Previous studies have shown that lung cancer stem cells express CD133 and that certain cancer stem cells express cancer germline antigens (CGAs). The transcriptional regulation of CD133 is complicated and poorly understood. We investigated CD133 and CGA expression in a non-small cell lung cancer cell line. Methods: The expression levels of CD133 and CGAs (MAGE-6, GAGE, SSX, and TRAG-3) were measured in an NCI-H292 lung cancer cell line. The methylation status of the CD133 gene promoter region was analyzed. The expression levels and promoter methylation statuses of CD133 and CGAs were confirmed by treatment with the demethylating agent 5-aza-2'-deoxycytidine (ADC). Results: After treatment with ADC, CD133 expression was no longer detected. MAGE-6 and TRAG-3 were detected before ADC treatment, while GAGE and SSX were not detected. ADC treatment upregulated MAGE-6 and TRAG-3 expression, while GAGE expression was still undetected after treatment, and only weak SSX expression was observed. GAGE expression was not correlated with expression of CD133, while the levels of expression of MAGE-6, TRAG-3, and SSX were inversely correlated with CD133 expression. Conclusion: These results showed that CD133 expression can be regulated by methylation. Thus, the demethylation of the CD133 promoter may compromise the treatment of lung cancer by inactivating cancer stem cells and/or activating CGAs.

Functions of TET Proteins in Hematopoietic Transformation

  • Han, Jae-A;An, Jungeun;Ko, Myunggon
    • Molecules and Cells
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    • v.38 no.11
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    • pp.925-935
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    • 2015
  • DNA methylation is a well-characterized epigenetic modification that plays central roles in mammalian development, genomic imprinting, X-chromosome inactivation and silencing of retrotransposon elements. Aberrant DNA methylation pattern is a characteristic feature of cancers and associated with abnormal expression of oncogenes, tumor suppressor genes or repair genes. Ten-eleven-translocation (TET) proteins are recently characterized dioxygenases that catalyze progressive oxidation of 5-methylcytosine to produce 5-hydroxymethylcytosine and further oxidized derivatives. These oxidized methylcytosines not only potentiate DNA demethylation but also behave as independent epigenetic modifications per se. The expression or activity of TET proteins and DNA hydroxymethylation are highly dysregulated in a wide range of cancers including hematologic and non-hematologic malignancies, and accumulating evidence points TET proteins as a novel tumor suppressor in cancers. Here we review DNA demethylation-dependent and -independent functions of TET proteins. We also describe diverse TET loss-of-function mutations that are recurrently found in myeloid and lymphoid malignancies and their potential roles in hematopoietic transformation. We discuss consequences of the deficiency of individual Tet genes and potential compensation between different Tet members in mice. Possible mechanisms underlying facilitated oncogenic transformation of TET-deficient hematopoietic cells are also described. Lastly, we address non-mutational mechanisms that lead to suppression or inactivation of TET proteins in cancers. Strategies to restore normal 5mC oxidation status in cancers by targeting TET proteins may provide new avenues to expedite the development of promising anti-cancer agents.

Decolorization and Biotransformation of Triphenylmethane Dye, Methyl Violet, by Aspergillus sp. Isolated from Ladakh, India

  • Kumar, C. Ganesh;Mongolla, Poornima;Basha, Anver;Joseph, Joveeta;Sarma, V.U.M.;Kamal, Ahmed
    • Journal of Microbiology and Biotechnology
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    • v.21 no.3
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    • pp.267-273
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    • 2011
  • Methyl violet, used extensively in the commercial textile industry and as a biological stain, is a hazardous recalcitrant. Aspergillus sp. strain CB-TKL-1 isolated from a water sample from Tsumoriri Lake, Karzok, Ladakh, India, was found to completely decolorize methyl violet within 24 h when cultured under aerobic conditions at $25^{\circ}C$. The rate of decolorization was determined by monitoring the decrease in the absorbance maxima of the dye by UV-visible spectroscopy. The decolorization of methyl violet was optimal at pH 5.5 and $30^{\circ}C$ when agitated at 200 rpm. Addition of glucose or arabinose (2%) as a carbon source and sodium nitrate or soyapeptone (0.2%) as a nitrogen source enhanced the decolorization ability of the culture. Furthermore, the culture exhibited a maximum decolorization rate of methyl violet after 24 h when the C:N ratio was 10. Nine N-demethylated decolorized products of methyl violet were identified based on UV-visible spectroscopy, Fourier transform infrared (FTIR), and LC-MS analyses. The decolorization of methyl violet at the end of 24 h generated mono-, di-, tri-, tetra-, penta-, and hexa-N-demethylated intermediates of pararosaniline. The variation of the relative absorption peaks in the decolorized sample indicated a linear decrease of hexa-N-demethylated compounds to non-N-demethylated pararosaniline, indicating a stepwise N-demethylation in the decolorization process.

Cold-induced ginsenosides accumulation is associated with the alteration in DNA methylation and relative gene expression in perennial American ginseng (Panax quinquefolius L.) along with its plant growth and development process

  • Hao, Mengzhen;Zhou, Yuhang;Zhou, Jinhui;Zhang, Min;Yan, Kangjiao;Jiang, Sheng;Wang, Wenshui;Peng, Xiaoping;Zhou, San
    • Journal of Ginseng Research
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    • v.44 no.5
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    • pp.747-755
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    • 2020
  • Background: Ginsenosides accumulation responses to temperature are critical to quality formation in cold-dependent American ginseng. However, the studies on cold requirement mechanism relevant to ginsenosides have been limited in this species. Methods: Two experiments were carried out: one was a multivariate linear regression analysis between the ginsenosides accumulation and the environmental conditions of American ginseng from different sites of China and the other was a synchronous determination of ginsenosides accumulation, overall DNA methylation, and relative gene expression in different tissues during different developmental stages of American ginseng after experiencing different cold exposure duration treatments. Results: Results showed that the variation of the contents as well as the yields of total and individual ginsenosides Rg1, Re, and Rb1 in the roots were closely associated with environmental temperature conditions which implied that the cold environment plays a decisive role in the ginsenoside accumulation of American ginseng. Further results showed that there is a cyclically reversible dynamism between methylation and demethylation of DNA in the perennial American ginseng in response to temperature seasonality. And sufficient cold exposure duration in winter caused sufficient DNA demethylation in tender leaves in early spring and then accompanied the high expression of flowering gene PqFT in flowering stages and ginsenosides biosynthesis gene PqDDS in green berry stages successively, and finally, maximum ginsenosides accumulation occurred in the roots of American ginseng. Conclusion: We, therefore, hypothesized that cold-induced DNA methylation changes might regulate relative gene expression involving both plant development and plant secondary metabolites in such cold-dependent perennial plant species.

Degradation of the herbicide dicamba under sunlight and in soil (제초제 Dicamba의 자연광 및 토양 중 분해)

  • Oh, Kyeong-Seok;Oh, Byung-Youl;Park, Seung-Soon;Ihm, Yang-Bin;Kyung, Kee-Sung;Lee, Jae-Koo
    • The Korean Journal of Pesticide Science
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    • v.4 no.3
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    • pp.1-6
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    • 2000
  • In order to elucidate the degradation of the herbicide dicamba, the degradabilities of dicamba under sunlight and in soils were investigated. The photodegradation rate of the authentic dicamba under sunlight condition was only 3.3% after 9 weeks. 4-Hydroxy dicamba turned out to be the major product, and 5-hydroxy dicamba was also identified. Dicamba was degraded to 3,6-dichlorosalicylic acid by demethylation in the viable soil, which resulted in 14.7 to 23.2% degradation of the applied amount during 8 weeks of incubation. Meanwhile, the degradation was quite slow in the sterilize soil, which revealed that the soil microbes played a major role in dicamba degradation.

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Metabolic Study on C29-Brassinosteroids in Young Rice Plants (벼 유식물을 이용한 C29-Brassinosteroids의 대사)

  • Won, So-Yun;Joo, Se-Hwan;Kim, Seong-Ki
    • Journal of Plant Biotechnology
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    • v.34 no.3
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    • pp.243-251
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    • 2007
  • It has been recently demonstrated the presence of not only $C_{28}-BRs$ biosysnthesis, but also $C_{27}-$ and $C_{29}-BRs$ biosynthesis in plants, suggesting that BRs biosynthesis are complicatedly connected to produce biologically active BR (s). This prompted us to investigation of metabolism of a $C_{29}-BR$, 28-homoCS in seedlings of rice from which $C_{29}-BRs$ such as 28-homoTE and 28-homoTY have been identified. In vitro enzyme conversion study using a crude enzyme solution prepared from rice seedlings revealed that 28-homoCS is converted into both CS and 26-nor-28-homoCS, but their reversed reaction did not occur. This indicated that 28-homoCS is biosynthetically converted into more biologically active $C_{28}-BR$, CS by C-28 demethylation and biodegraded into 26-nor-28-homoCS by C-26 demethylation. Next, bio-conversion of 28-homoCS to 28-homoBL was examined by the same enzyme solution. No 28-homoBL as a metabolite of 28-homoCS was detected, meaning that biosynthetic reaction for 28-homoCS to 28-homoBL is not contained, and main connection of $C_{28}-BRs$ and $C_{29}-BRs$ biosynthesis is between CS and 28-homoCS in the rice seedling. This study is the first demonstrated that $C_{29}-BRs$ and $C_{28}-BRs$ bionsynthetic pathways are connected, and that $C_{29}-BRs$ biosynthetic pathway is an alternative biosynthetic pathway to produce more biologically active $C_{28}-BR$, CS in plant.

Role of CAGE, a Novel Cancer/Testis Antigen, in Various Cellular Processes, Including Tumorigenesis, Cytolytic T Lymphocyte Induction, and Cell Motility

  • Kim, Young-Mi;Jeoung, Doo-Il
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.600-610
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    • 2008
  • A cancer-associated antigen gene (CAGE) was identified by serological analysis of a recombinant cDNA expression library (SEREX). The gene was identified by screening cDNA expression libraries of human testis and gastric cancer cell lines with sera from patients with gastric cancer. CAGE was found to contain a D-E-A-D box domain and encodes a putative protein of 630 amino acids with possible helicase activity. The CAGE gene is widely expressed in various cancer tissues and cancer cell lines. Demethylation plays a role in the activation of CAGE in certain cancer cell lines where the gene is not expressed. The functional roles of CAGE in tumorigenesis, the molecular mechanisms of CAGE expression, and cell motility are also discussed.

Synthesis of Higenamine, A Cardiotonic Principle of Aconite Root

  • Chang, Ki-Churl;Choi, Sook-Yun;Lim, Jung-Kyoo;Park, Chan-Woong
    • Archives of Pharmacal Research
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    • v.7 no.2
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    • pp.133-136
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    • 1984
  • Higenamine (I), cardiotonic principle of Aconite root, was synthesized from 4-methoxy-phenylacetic acid (II) and .betha.-(3, 4-dimethoxyphenyl)-ethylamine (IV). Condensation of IV with 4-mehoxyphenylacetyl chloride (III) was followed by cyclodehydration yielding 1-(4'-methoxybenzyl)-6, 7- dimethoxy-3, 4-dihydroisoquinoline (VI). Reduction of VI to 1, 2, 3, 4-tetrahydroisoquinoline (VII) and subsequent demethylation provided desired product higenamine, 1-(4'-hydroxybenzyl)-6, 7- dihydroxy-1, 2, 3, 4, -tetrahydroisoquinoline.

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Current status and prospects of epigenetic information in sexual reproductive processes of plants (식물 유성 생식과정에서 후성유전학적 정보해석 및 연구현황)

  • Jung, Yu Jin;Cho, Yong-Gu;Kang, Kwon Kyoo
    • Journal of Plant Biotechnology
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    • v.44 no.1
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    • pp.19-26
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    • 2017
  • Rapid progress in epigenetic studies has resulted in genome wide information of genetic functions, other than DNA sequence information. However, insufficient understanding and unclear research direction in epigenetics has failed to attract many researchers. Here, we review the sexual reproduction processes that are particularly related to epigenetics in plants. We aim to elucidate the roles of epigenetic information and molecular mechanisms involved in the complex sexual reproduction process of plants, and examine their biological significance.