Wyniki wyszukiwania - Biblioteka Nauki

1

DNA methylation: gene expression regulation

100%

Zmarzły N. , Wojdas E. , Skubis A. , Sikora B. , Mazurek U.

Acta Universitatis Lodziensis. Folia Biologica et Oecologica

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2016

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tom 12

1-10

PL

Modyfikacje epigenetyczne odpowiedzialne są za modulację ekspresji genów bez ingerencji w sekwencję nukleotydową. Obserwowane zmiany aktywności transkrypcyjnej genów w tkankach nowotworowych w porównaniu do tkanki prawidłowej, bardzo często są wynikiem metylacji DNA w obrębie sekwencji promotorowych tych genów. Modyfikacja ta poprzez przyłączenie grup metylowych do cytozyn wysp CpG skutkuje wyciszeniem aktywności transkrypcyjnej genu, co w przypadku genów supresorowych przejawia się zaburzeniami cyklu komórkowego, nadmierną proliferacją i destabilizacją procesów naprawczych. Dalsze badania nad modyfikacjami epigenetycznymi pozwolą na lepsze zrozumienie mechanizmów ich działania, w tym zależności pomiędzy metylacją DNA, a aktywnością białek decydujących o strukturze chromatyny i aktywności genów. Poszerzanie wiedzy na temat epigenetycznych mechanizmów biorących udział w procesie transformacji nowotworowej i farmakologicznej regulacji stopnia metylacji DNA może stanowić okazję do poprawy działań terapeutycznych w walce z nowotworem.

EN

Epigenetic modifications are responsible for the modulation of gene expression without affecting the nucleotide sequence. The observed changes in transcriptional activity of genes in tumor tissue compared to normal tissue, are often the result of DNA methylation within the promoter sequences of these genes. This modification by attaching methyl groups to cytosines within CpG islands results in silencing of transcriptional activity of the gene, which in the case of tumor suppressor genes is manifested by abnormal cell cycle, proliferation and excessive destabilization of the repair processes. Further studies of epigenetic modifications will allow a better understanding of mechanisms of their action, including the interdependence between DNA methylation and activity of proteins crucial to the structure of chromatin and gene activity. Wider knowledge of epigenetic mechanisms involved in the process of malignant transformation and pharmacological regulation of the degree of DNA methylation provides an opportunity to improve the therapeutic actions in the fight against cancer.

2

Number, size and transcriptional activity of nucleoli during different periods of interphase in antheridial filaments of Chara vulgaris L.

100%

Maszewski J. , Kwiatkowska M.

Folia Histochemica et Cytobiologica

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1984

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tom 22

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nr 1

3

Transcriptional activity of telomerase complex in CD34minus stem cells of cord blood in dependence of preparation time

75%

Stojko R. , Witek A. , Glogowska-Lingus J. , Mazurek U. , Chromy G. , Dworzecki T. , Bojdys-Szyndlar M. , Machaj K. , Pojda Z.

Folia Histochemica et Cytobiologica

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2009

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tom 47

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nr 2

265-274

4

Changes in the activity of transport of newly synthesized RNA from nucleus into cytoplasm during interphase

75%

Kwiatkowska M. , Maszewski J.

Folia Histochemica et Cytobiologica

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1985

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tom 23

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nr 3

5

Post-transcriptional modifications of VEGF-A mRNA in non-ischemic dilated cardiomyopathy

75%

Kowalczyk J. , Domal-Kwiatkowska D. , Mazurek U. , Zembala M. , Michalski B. , Zembala M.

Cellular and Molecular Biology Letters

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2007

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tom 12

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nr 3

EN

Vascular endothelial growth factor (VEGF-A) is one of the most important proangiogenic factors. It has many isoforms encoded by one gene. The occurrence of these isoforms is associated with the process of alternative splicing of mRNA. Some of the splice forms are perceived as tissue specific. The aim of this study was to determine the alternative splicing of VEGF-A mRNA in dilated cardiomyopathy, especially at the level of particular myocardial layers. The assessment of post-transcriptional modifications of VEGF-A mRNA was made on specimens taken from the explanted hearts of patients undergoing cardiac transplantation. Molecular and histopathological studies were perfomed on particular layers of the myocardial muscle (endocardium, myocardium, epicardium). A molecular analysis of cardiac samples was performed by quantitative analysis of the mRNA of the studied VEGF-A isoforms (VEGF121, -145, -165, -183, -189, and -206) using QRTPCR with an ABI-PRISM 7700-TaqMan sequence detector. 72 cardiac specimens taken from the explanted hearts were analyzed. Each of the studied VEGF-A splice forms was present in the evaluated hearts, but the types of alternative splicing of mRNA were different in particular layers. Quantitative analysis revealed different amounts of the studied isoforms. Generally, significantly increased expression of the VEGF-A isoforms was observed in samples taken from hearts with post-inflammatory etiology of cardiomyopathy. Our conclusions are: 1. All the studied VEGF-A isoforms were found in the human hearts, including those thusfar considered characteristic for other tissues. 2. Significant differences were observed in the expression of the VEGF-A splice forms with respect to the myocardial layers and the location of the cardiac biopsy. 3. Repetitive and comparable results for samples with post-inflammatory etiology were obtained, and they revealed considerably higher amounts of VEGF-A isoforms compared to specimens with idiopathic etiology.

6

Study of rRNA transcripts distribution against a background of total transcriptional activity of Hyacinthus orientalis L. female gametophyte cells before and after fertilization

63%

Piecinski S. , Niedojadlo K. , Smolinski D. J. , Bednarska E.

Acta Biologica Cracoviensia. Series Botanica. Supplement

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2008

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tom 50

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nr 1

7

Transcriptional activity changes of the SOC1 homologue in vegetative organs in Lupinus luteus

63%

Wojciechowski W. , Glazinska P. , Banach M. , Wilmowicz E. , Kucko A. , Marciniak K. , Kesy J. , Kopcewicz J. , Tretyn A.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2013

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tom 94

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nr 3

8

Transcriptional activity of a complex of wheat RNA polymerase II and nonhistone chromosomal protein (NHCP)

63%

Dullin P. , Galbas M. , Chodynicka-Kordus G. , Fabisz-Kijowska A. , Walerych W.

Acta Biochimica Polonica

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1989

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tom 36

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nr 3-4

9

Transcriptional activity of Petunia calreticulin gene (PhCRT) involved in pistil transmitting tract maturation, progamic phase and double fertilization

63%

Suwinska A. , Lenartowski R. , Lenartowska M.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2013

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tom 94

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nr 3

10

Expression of FOXJ1 and ITGB4 is activated upon KLH and LTA stimulation in the DT40 cell line

63%

Dunislawska A. , Slawinska A. , Siwek M.

Folia Biologica

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2017

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tom 65

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nr 1

11

Functional and structural heterogeneity of nucleoli: the dependence of the activity of transport of newly synthesized rRNA on nucleolar size and phase of the cell cycle

63%

Kwiatkowska M. , Maszewski J.

Folia Histochemica et Cytobiologica

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1985

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tom 23

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nr 3

12

Changes in distribution of 5' methylcytosine in male and female gametophyte of Hyacinthus orientalis before and after fertilization

51%

Kozlowska M. , Niedojadlo K. , Bednarska-Kozakiewicz E.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2013

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tom 94

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nr 3

13

Structure and functions of lampbrush chromosomes

51%

Andraszek K. , Smalec E.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2011

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tom 92

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nr 4