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Expressão de marcadores moleculares em espermatogônias; Expression of molecular markers in spermatogonia

Giassetti, Mariana Ianello
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/06/2015 PT
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66.03%
Em mamíferos, a espermatogênese é mantida pela autorrenovação e diferenciação das células-tronco espermatogoniais (SSC). Apesar da grande importância do SSC para a fertilidade masculina, em Bos taurus pouco se sabe sobre a sua identificação e biologia celular. Para roedores, mais de 30 marcadores para células germinativas indiferenciadas já foram descritos. No entanto, ainda não é conhecido um marcador específico apenas para SSC. Quase todos são também expressos por gonócitos, espermatogônias mais diferenciadas ou mesmo células somáticas. Yin Yang 2 (YY2) é um factor de transcrição expresso nas células com a morfologia de gonócitos e SSC, sendo um candidato a marcador de SSC. Assim, a identificação de novos marcadores para SSC e factores que afectam a sua expressão, tais como a idade, são fundamentais para o desenvolvimento da biotecnologia como transgenia e tratamento de infertilidade, nos quais as SSC poderiam ser ferramentas biológicos importantes. Assim, nesta tese temos duas hipóteses principais: 1) a idade do dador afeta a expressão de marcadores moleculares específicos de SSC bovinas assim como potencial de células-tronco dessas células e que as sequências de DNA em que se associa YY2 regulam a expressão génica de SSC em camundongos. Os objetivos específicos...

Oct-2 DNA binding transcription factor: functional consequences of phosphorylation and glycosylation

Ahmad, Ishtiaq; Hoessli, Daniel C.; Walker-Nasir, Evelyne; Rafik, Saleem M.; Shakoori, Abdul R.; Nasir-ud-Din,
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
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Phosphorylation and O-GlcNAc modification often induce conformational changes and allow the protein to specifically interact with other proteins. Interplay of phosphorylation and O-GlcNAc modification at the same conserved site may result in the protein undergoing functional switches. We describe that at conserved Ser/Thr residues of human Oct-2, alternative phosphorylation and O-GlcNAc modification (Yin Yang sites) can be predicted by the YinOYang1.2 method. We propose here that alternative phosphorylation and O-GlcNAc modification at Ser191 in the N-terminal region, Ser271 and 274 in the linker region of two POU sub-domains and Thr301 and Ser323 in the POUh subdomain are involved in the differential binding behavior of Oct-2 to the octamer DNA motif. This implies that phosphorylation or O-GlcNAc modification of the same amino acid may result in a different binding capacity of the modified protein. In the C-terminal domain, Ser371, 389 and 394 are additional Yin Yang sites that could be involved in the modulation of Oct-2 binding properties.

Human acyl-CoA:cholesterol acyltransferase 2 gene expression in intestinal Caco-2 cells and in hepatocellular carcinoma

Song, Bao-Liang; Wang, Can-Hua; Yao, Xiao-Min; Yang, Li; Zhang, Wen-Jing; Wang, Zhen-Zhen; Zhao, Xiao-Nan; Yang, Jin-Bo; Qi, Wei; Yang, Xin-Ying; Inoue, Kenji; Lin, Zhi-Xin; Zhang, Hui-Zhan; Kodama, Tatsuhiko; Chang, Catherine C. Y.; Liu, Yin-Kun; Chang
Fonte: Portland Press Ltd. Publicador: Portland Press Ltd.
Tipo: Artigo de Revista Científica
EN
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35.79%
Humans express two ACAT (acyl-CoA:cholesterol acyltransferase) genes, ACAT1 and ACAT2. ACAT1 is ubiquitously expressed, whereas ACAT2 is primarily expressed in intestinal mucosa and plays an important role in intestinal cholesterol absorption. To investigate the molecular mechanism(s) responsible for the tissue-specific expression of ACAT2, we identified five cis-elements within the human ACAT2 promoter, four for the intestinal-specific transcription factor CDX2 (caudal type homeobox transcription factor 2), and one for the transcription factor HNF1α (hepatocyte nuclear factor 1α). Results of luciferase reporter and electrophoretic mobility shift assays show that CDX2 and HNF1α exert a synergistic effect, enhancing the ACAT2 promoter activity through binding to these cis-elements. In undifferentiated Caco-2 cells, the ACAT2 expression is increased when exogenous CDX2 and/or HNF1α are expressed by co-transfection. In differentiated Caco-2 cells, the ACAT2 expression significantly decreases when the endogenous CDX2 or HNF1α expression is suppressed by using RNAi (RNA interference) technology. The expression levels of CDX2, HNF1α, and ACAT2 are all greatly increased when the Caco-2 cells differentiate to become intestinal-like cells. These results provide a molecular mechanism for the tissue-specific expression of ACAT2 in intestine. In normal adult human liver...

Identification of Yin-Yang Regulators and a Phosphorylation Consensus for Male Germ Cell-Associated Kinase (MAK)-Related Kinase▿

Fu, Zheng; Larson, Katherine A.; Chitta, Raghu K.; Parker, Sirlester A.; Turk, Benjamin E.; Lawrence, Matthew W.; Kaldis, Philipp; Galaktionov, Konstantin; Cohn, Steven M.; Shabanowitz, Jeffrey; Hunt, Donald F.; Sturgill, Thomas W.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
EN
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45.84%
MAK (male germ cell-associated protein kinase) and MRK/ICK (MAK-related kinase/intestinal cell kinase) are human homologs of Ime2p in Saccharomyces cerevisiae and of Mde3 and Pit1 in Schizosaccharomyces pombe and are similar to human cyclin-dependent kinase 2 (CDK2) and extracellular signal-regulated kinase 2 (ERK2). MAK and MRK require dual phosphorylation in a TDY motif catalyzed by an unidentified human threonine kinase and tyrosine autophosphorylation. Herein, we establish that human CDK-related kinase CCRK (cell cycle-related kinase) is an activating T157 kinase for MRK, whereas active CDK7/cyclin H/MAT1 complexes phosphorylate CDK2 but not MRK. Protein phosphatase 5 (PP5) interacts with MRK in a complex and dephosphorylates MRK at T157 in vitro and in situ. Thus, CCRK and PP5 are yin-yang regulators of T157 phosphorylation. To determine a substrate consensus, we screened a combinatorial peptide library with active MRK. MRK preferentially phosphorylates R-P-X-S/T-P sites, with the preference for arginine at position −3 (P−3) being more stringent than for prolines at P−2 and P+1. Using the consensus, we identified a putative phosphorylation site (RPLT1080S) for MRK in human Scythe, an antiapoptotic protein that interacts with MRK. MRK phosphorylates Scythe at T1080 in vitro as determined by site-directed mutagenesis and mass spectrometry...

Yin Yang 1 deficiency in skeletal muscle protects against rapamycin-induced diabetic-like symptoms through activation of insulin/IGF signaling

Blättler, Sharon M.; Cunningham, John T.; Verdeguer, Francisco; Chim, Helen; Haas, Wilhelm; Liu, Huifei; Romanino, Klaas; Rüegg, Markus A.; Gygi, Steven P.; Shi, Yang; Puigserver, Pere
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 04/04/2012 EN
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45.71%
Rapamycin and derivatives are mTOR inhibitors used in tissue transplantation and cancer therapy. A percentage of patients treated with these inhibitors develop diabetic-like symptoms but the molecular mechanisms are unknown. We show here that chronic rapamycin treatment in mice leads to insulin resistance with suppression of insulin/IGF signaling and genes associated within this pathway, such as IGFs, IRS1/2 and AKTs. Importantly, skeletal muscle-specific YY1 knockout mice were protected from rapamycin-induced diabetic-like symptoms. This protection was caused by hyperactivation of insulin/IGF signaling with increases in genes in this cascade that, in contrast to wild-type mice, were not suppressed by rapamycin. Mechanistically, rapamycin induced YY1 dephosphorylation and recruitment to promoters of insulin/IGF genes, which promoted interaction with the polycomb protein-2 corepressor. This was associated with H3K27 tri-methylation leading to decreases in gene expression and insulin signaling. These results have implications for rapamycin action in human diseases and biological processes, such as longevity.

APC Yin-Yang haplotype associated with colorectal cancer risk

GARRE, P.; DE LA HOYA, M.; INIESTA, P.; ROMERA, A.; LLOVET, P.; GONZALEZ, S.; PEREZ-SEGURA, P.; CAPELLA, G.; DIAZ-RUBIO, E.; CALDES, T.
Fonte: D.A. Spandidos Publicador: D.A. Spandidos
Tipo: Artigo de Revista Científica
EN
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46.09%
The Yin-Yang haplotype is defined as two mismatched haplotypes (Yin and Yang) representing the majority of the existing haplotypes in a particular genomic region. The human adenomatous polyposis coli (APC) gene shows a Yin-Yang haplotype pattern accounting for 84% of all of the haplotypes existing in the Spanish population. Several association studies have been published regarding APC gene variants (SNPs and haplotypes) and colorectal cancer (CRC) risk. However, no studies concerning diplotype structure and CRC risk have been conducted. The aim of the present study was to investigate whether the APC Yin-Yang homozygote diplotype is over-represented in patients with sporadic CRC when compared to its distribution in controls, and its association with CRC risk. TaqMan® assays were used to genotype three tagSNPs selected across the APC Yin-Yang region. Frequencies of the APC Yin-Yang tagSNP alleles, haplotype and diplotype of 378 CRC cases and 642 controls were compared. Two Spanish CRC group samples were included [Hospital Clínico San Carlos in Madrid (HCSC) and Instituto Catalán de Oncología in Barcelona (ICO)]. Analysis of 157 consecutive CRC patients and 405 control subjects from HCSC showed a significative effect for the risk of CRC (OR=1.93; 95% CI 1.32–2.81; P=0.001). However...

Collaborative interplay between FGF-2 and VEGF-C promotes lymphangiogenesis and metastasis

Cao, Renhai; Ji, Hong; Feng, Ninghan; Zhang, Yin; Yang, Xiaojuan; Andersson, Patrik; Sun, Yuping; Tritsaris, Katerina; Hansen, Anker Jon; Dissing, Steen; Cao, Yihai
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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45.67%
Interplay between various lymphangiogenic factors in promoting lymphangiogenesis and lymphatic metastasis remains poorly understood. Here we show that FGF-2 and VEGF-C, two lymphangiogenic factors, collaboratively promote angiogenesis and lymphangiogenesis in the tumor microenvironment, leading to widespread pulmonary and lymph-node metastases. Coimplantation of dual factors in the mouse cornea resulted in additive angiogenesis and lymphangiogenesis. At the molecular level, we showed that FGFR-1 expressed in lymphatic endothelial cells is a crucial receptor that mediates the FGF-2–induced lymphangiogenesis. Intriguingly, the VEGFR-3–mediated signaling was required for the lymphatic tip cell formation in both FGF-2– and VEGF-C–induced lymphangiogenesis. Consequently, a VEGFR-3–specific neutralizing antibody markedly inhibited FGF-2–induced lymphangiogenesis. Thus, the VEGFR-3–induced lymphatic endothelial cell tip cell formation is a prerequisite for FGF-2–stimulated lymphangiogenesis. In the tumor microenvironment, the reciprocal interplay between FGF-2 and VEGF-C collaboratively stimulated tumor growth, angiogenesis, intratumoral lymphangiogenesis, and metastasis. Thus, intervention and targeting of the FGF-2– and VEGF-C–induced angiogenic and lymphangiogenic synergism could be potentially important approaches for cancer therapy and prevention of metastasis.

Transcription Regulator Yin-Yang 1: From Silence to Cancer

Zhu, Weidong; Olson, Samuel Y.; Garbán, Hermes J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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45.79%
Yin Yang (YY) 1 represents the epitome of what is considered to be a “Swiss army knife” transcription factor and regulator. YY1 is a ubiquitous and multifunctional zinc-finger transcription factor member of the Polycomb group protein family, a group of homeobox gene receptors that can act as activators or repressors of transcriptional activity. Furthermore, YY1 can act as a redox sensor, adaptor molecule, and chromatin structure and function regulator. YY1’s characteristic function as transcriptional activator and repressor relies on its C2H2 (x4) zinc-finger structural DNA-binding motifs tangled with 2 specific regulatory domains. This structural conformation will render the activity of YY1 susceptible to changes in cellular redox status. YY1 also has been shown to undergo chromatin remodeling via interactions with histone acetyl transferase and histone deacetylase complexes. Both groups modify histones, resulting in altered chromatin structure. Herein, we will discuss the multiple roles and mechanisms of YY1 in the regulation of gene expression, its genetic factor functions, epigenetic regulatory activity, and its role as a redox sensor in the context of malignant neoplastic diseases.

Inhibition of Yin Yang 1-Dependent Repressor Activity of DR5 Transcription and Expression by the Novel Proteasome Inhibitor NPI-0052 Contributes to its TRAIL-Enhanced Apoptosis in Cancer Cells1

Baritaki, Stavroula; Suzuki, Eriko; Umezawa, Kazuo; Spandidos, Demetrios A.; Berenson, James; Daniels, Tracy R.; Penichet, Manuel L.; Jazirehi, Ali R.; Palladino, Michael; Bonavida, Benjamin
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/05/2008 EN
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TRAIL promotes apoptotic tumor cell death; however, TRAIL-resistant tumors need to be sensitized to reverse resistance. Proteasome inhibitors potentiate TRAIL apoptosis in vitro and in vivo and correlate with up-regulation of death receptor 5 (DR5) via an unknown mechanism. We hypothesized that the proteasome inhibitor NPI-0052 inhibits the transcription repressor Yin Yang 1 (YY1) which regulates TRAIL resistance and negatively regulates DR5 transcription. Treatment of PC-3 and Ramos cells with NPI-0052 (≤2.5 nM) and TRAIL sensitizes the tumor cells to TRAIL-induced apoptosis. By comparison to bortezomib, a 400-fold less concentration of NPI-0052 was used. NPI-0052 up-regulated DR5 reporter activity and both surface and total DR5 protein expression. NPI-0052-induced inhibition of NF-κB activity was involved in TRAIL sensitization as corroborated by the use of the NF-κB inhibitor dehydroxymethylepoxyquinomicin. NPI-0052 inhibited YY1 promoter activity as well as both YY1 mRNA and protein expression. The direct role of NPI-0052-induced inhibition of YY1 and up-regulation of DR5 in the regulation of TRAIL sensitivity was demonstrated by the use of YY1 small interfering RNA. The NPI-0052-induced sensitization to TRAIL involved activation of the intrinsic apoptotic pathway and dysregulation of genes that regulate apoptosis. The NPI-0052 concentrations used for TRAIL sensitization were not toxic to human hematopoetic stem cells. The present findings demonstrate...

Decreased Genetic Dosage of Hepatic Yin Yang 1 Causes Diabetic-Like Symptoms

Verdeguer, Francisco; Blättler, Sharon M.; Cunningham, John T.; Hall, Jessica A.; Chim, Helen; Puigserver, Pere
Fonte: Endocrine Society Publicador: Endocrine Society
Tipo: Artigo de Revista Científica
EN
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45.79%
Insulin sensitivity in liver is characterized by the ability of insulin to efficiently inhibit glucose production and fatty acid oxidation as well as promote de novo lipid biosynthesis. Specific dysregulation of glucose and lipid metabolism in liver is sufficient to cause insulin resistance and type 2 diabetes; this is seen by a selective inability of insulin to suppress glucose production while remaining insulin-sensitive to de novo lipid biosynthesis. We have previously shown that the transcription factor Yin Yang 1 (YY1) controls diabetic-linked glucose and lipid metabolism gene sets in skeletal muscle, but whether liver YY1-targeted metabolic genes impact a diabetic phenotype is unknown. Here we show that decreased genetic dosage of YY1 in liver causes insulin resistance, hepatic lipid accumulation, and dyslipidemia. Indeed, YY1 liver-specific heterozygous mice exhibit blunted activation of hepatic insulin signaling in response to insulin. Mechanistically, YY1, through direct recruitment to promoters, functions as a suppressor of genes encoding for metabolic enzymes of the gluconeogenic and lipogenic pathways and as an activator of genes linked to fatty acid oxidation. These counterregulatory transcriptional activities make targeting hepatic YY1 an attractive approach for treating insulin-resistant diabetes.

Yin Yang 1 regulates the transcriptional repression of survivin

Galloway, Nicholas R.; Osterman, Carlos J. Diaz; Reiber, Karl; Jutzy, Jessica M.S.; Li, Fengzhi; Sui, Guangchao; Soto, Ubaldo; Wall, Nathan R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
45.79%
The mechanisms for regulation of the Inhibitor of Apoptosis (IAP) Survivin in cells undergoing stress associated with tumor development and the tumor microenvironment are not well understood. The stress response transcription factors HIF-1α and Yin Yang 1 (YY1) were hypothesized to contribute to the upregulation of Survivin in tumor cells. As expected, U2OS cells overexpressing HIF-1α showed a 2- to 3-fold transactivation when transfected. Surprisingly, when YY1 was overexpressed in this survivin promoter reporter system, luciferase expression was repressed 30- to 40-fold. YY1 involvement in survivin promoter repression was confirmed using siRNA directed against YY1. These studies showed that knockdown of YY1 releases the survivin promoter from the observed repression and leads to a 3- to 5-fold increase in promoter activity above basal levels. A U2OS cell line containing a stable YY1 Tet-off system was used to determine whether a temporal increase in YY1 expression affects Survivin protein levels. A low to moderate decrease in Survivin protein was observed 24 h and 48 h after Tet removal. Studies also confirmed that YY1 is capable of directly binding to the survivin promoter. Collectively, these findings identify novel basal transcriptional requirements of survivin gene expression which are likely to play important roles in the development of cancer and resistance to its treatment.

An ancient Chinese wisdom for metabolic engineering: Yin-Yang

Wu, Stephen G; He, Lian; Wang, Qingzhao; Tang, Yinjie J
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 20/03/2015 EN
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45.89%
In ancient Chinese philosophy, Yin-Yang describes two contrary forces that are interconnected and interdependent. This concept also holds true in microbial cell factories, where Yin represents energy metabolism in the form of ATP, and Yang represents carbon metabolism. Current biotechnology can effectively edit the microbial genome or introduce novel enzymes to redirect carbon fluxes. On the other hand, microbial metabolism loses significant free energy as heat when converting sugar into ATP; while maintenance energy expenditures further aggravate ATP shortage. The limitation of cell “powerhouse” prevents hosts from achieving high carbon yields and rates. Via an Escherichia coli flux balance analysis model, we further demonstrate the penalty of ATP cost on biofuel synthesis. To ensure cell powerhouse being sufficient in microbial cell factories, we propose five principles: 1. Take advantage of native pathways for product synthesis. 2. Pursue biosynthesis relying only on pathways or genetic parts without significant ATP burden. 3. Combine microbial production with chemical conversions (semi-biosynthesis) to reduce biosynthesis steps. 4. Create “minimal cells” or use non-model microbial hosts with higher energy fitness. 5. Develop a photosynthesis chassis that can utilize light energy and cheap carbon feedstocks. Meanwhile...

Interleukin-18 Down-Regulates Multidrug Resistance-Associated Protein 2 Expression through Farnesoid X Receptor Associated with Nuclear Factor Kappa B and Yin Yang 1 in Human Hepatoma HepG2 Cells

Liu, Xiao-cong; Lian, Wei; Zhang, Liang-jun; Feng, Xin-chan; Gao, Yu; Li, Shao-xue; Liu, Chang; Cheng, Ying; Yang, Long; Wang, Xiao-Juan; Chen, Lei; Wang, Rong-quan; Chai, Jin; Chen, Wen-sheng
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 20/08/2015 EN
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55.87%
Multidrug resistance-associated protein 2 (MRP2) plays an important role in bile acid metabolism by transporting toxic organic anion conjugates, including conjugated bilirubin, glutathione, sulfate, and multifarious drugs. MRP2 expression is reduced in cholestatic patients and rodents. However, the molecular mechanism of MRP2 down-regulation remains elusive. In this report, we treated human hepatoma HepG2 cells with interleukin-18 (IL-18) and measured the expression of MRP2, nuclear factor kappa B (NF-κB), farnesoid X receptor (FXR), and the transcription factor Yin Yang 1 (YY1) by quantitative real-time quantitative polymerase chain reaction (PCR) and western blotting. We found that expression of MRP2 was repressed by IL-18 at both the mRNA and protein levels in a dose- and time-dependent manner. Furthermore, the activated NF-κB pathway increased YY1 and reduced FXR. These changes were all attenuated in HepG2 cells with knockdown of the NF-κB subunit, p65. The reduced expression of FXR and MRP2 in HepG2 cells that had been caused by IL-18 treatment was also attenuated by YY1 knockdown. We further observed significantly elevated IL-18, NF-κB, and YY1 expression and decreased FXR and MRP2 expression in bile duct-ligated Sprague Dawley rat livers. Chromatin immunoprecipitation assays also showed that FXR bound to the promoter region in MRP2 was less abundant in liver extracts from bile duct-ligated rats than sham-operated rats. Our findings indicate that IL-18 down-regulates MRP2 expression through the nuclear receptor FXR in HepG2 cells...

Yin Yang Gene Expression Ratio Signature for Lung Cancer Prognosis

Xu, Wayne; Banerji, Shantanu; Davie, James R.; Kassie, Fekadu; Yee, Douglas; Kratzke, Robert
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/07/2013 EN
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36.06%
Many studies have established gene expression-based prognostic signatures for lung cancer. All of these signatures were built from training data sets by learning the correlation of gene expression with the patients' survival time. They require all new sample data to be normalized to the training data, ultimately resulting in common problems of low reproducibility and impracticality. To overcome these problems, we propose a new signature model which does not involve data training. We hypothesize that the imbalance of two opposing effects in lung cancer cells, represented by Yin and Yang genes, determines a patient’s prognosis. We selected the Yin and Yang genes by comparing expression data from normal lung and lung cancer tissue samples using both unsupervised clustering and pathways analyses. We calculated the Yin and Yang gene expression mean ratio (YMR) as patient risk scores. Thirty-one Yin and thirty-two Yang genes were identified and selected for the signature development. In normal lung tissues, the YMR is less than 1.0; in lung cancer cases, the YMR is greater than 1.0. The YMR was tested for lung cancer prognosis prediction in four independent data sets and it significantly stratified patients into high- and low-risk survival groups (p = 0.02...

Yin Yang 1 is a target of microRNA-34 family and contributes to gastric carcinogenesis

Wang, An-Ming; Huang, Tzu-Ting; Hsu, Kai-Wen; Huang, Kuo-Hung; Fang, Wen-Liang; Yang, Muh-Hwa; Lo, Su-Shun; Chi, Chin-Wen; Lin, Jing-Jer; Yeh, Tien-Shun
Fonte: Impact Journals LLC Publicador: Impact Journals LLC
Tipo: Artigo de Revista Científica
Publicado em 07/06/2014 EN
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55.83%
Gastric cancer is the second leading cause of cancer-related death worldwide. Herein, we investigated the role of transcription factor Yin Yang 1 (YY1), a multi-functional protein, in tumorigenesis of gastric cancer cells. Results showed that YY1 contributed to gastric carcinogenesis of SC-M1 cells including growth, viability, and abilities of colony formation, migration, invasion, and tumorsphere formation. Levels of pluripotency genes CD44, Oct4, SOX-2, and Nanog were also up-regulated by YY1 in SC-M1 cells. Additionally, the 3'-untranslated region (3'-UTR) of YY1 mRNA was the target of microRNA-34 (miR-34) family consisting of miR-34a, miR-34b, and miR-34c. Overexpression of miR-34 family suppressed carcinogenesis through down-regulation of YY1 in NUGC-3 gastric cancer cells scarcely expressing miR-34 family. Alternatively, knockdown of miR-34 family promoted tumorigenesis via up-regulation of YY1 in SC-M1 and AZ521 gastric cancer cells with higher levels of miR-34 family. The miR-34 family also affected tumorsphere ultra-structure and inhibited the xenografted tumor growth as well as lung metastasis of SC-M1 cells through YY1. Expressions of miR-34a and miR-34c in gastric cancer tissues of patients were lower than those in normal tissues. Taken together...

Transcription factor Yin-Yang 2 alters neuronal outgrowth in vitro

Klar, Martin; Fenske, Pascal; Vega, Fanny Rezza; Dame, Christof; Bräuer, Anja U.
Fonte: Springer Berlin Heidelberg Publicador: Springer Berlin Heidelberg
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
65.82%
The Yin-Yang 2 (YY2) protein is the most recently described member of the family of YY transcription factors. Despite its high structural and functional homology with the well-characterized YY1, less is known about its role in biological processes. In previous studies, we have found differential yy2 mRNA expression levels in various cell types of the murine brain. To investigate the functional implication of yy2 in neurons, we have examined the influence of altered cellular yy2 concentrations during neuronal differentiation. Our results indicate that both the up- and down-regulation of yy2 significantly impairs the outgrowth of the major neurite of primary hippocampal neurons and the numbers of neuronal processes in proximate extensions. Moreover, enhanced expression of wild-type yy2 results in increased cell death, whereas elevated expression levels of a yy2 DNA-binding mutant have no effect on cell viability. Therefore, stringent regulation of the cellular yy2 content might be needed to ensure proper neurite outgrowth and cell vitality.

Fermat's spiral and the line between Yin and Yang

Banakh, Taras; Verbitsky, Oleg; Vorobets, Yaroslav
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
35.89%
Let $D$ denote a disk of unit area. We call a subset $A$ of $D$ perfect if it has measure 1/2 and, with respect to any axial symmetry of $D$, the maximal symmetric subset of $A$ has measure 1/4. We call a curve $\beta$ in $D$ an yin-yang line if $\beta$ splits $D$ into two congruent perfect sets, $\beta$ crosses each concentric circle of $D$ twice, $\beta$ crosses each radius of $D$ once. We prove that Fermat's spiral is a unique yin-yang line in the class of smooth curves algebraic in polar coordinates.; Comment: 20 pages, 7 figures. In the 2nd version, a minor correction is made

Matrix genetics, part 2: the degeneracy of the genetic code and the octave algebra with two quasi-real units (the genetic octave Yin-Yang-algebra)

Petoukhov, Sergey V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.96%
Algebraic properties of the genetic code are analyzed. The investigations of the genetic code on the basis of matrix approaches ("matrix genetics") are described. The degeneracy of the vertebrate mitochondria genetic code is reflected in the black-and-white mosaic of the (8*8)-matrix of 64 triplets, 20 amino acids and stop-signals. This mosaic genetic matrix is connected with the matrix form of presentation of the special 8-dimensional Yin-Yang-algebra and of its particular 4-dimensional case. The special algorithm, which is based on features of genetic molecules, exists to transform the mosaic genomatrix into the matrices of these algebras. Two new numeric systems are defined by these 8-dimensional and 4-dimensional algebras: genetic Yin-Yang-octaves and genetic tetrions. Their comparison with quaternions by Hamilton is presented. Elements of new "genovector calculation" and ideas of "genetic mechanics" are discussed. These algebras are considered as models of the genetic code and as its possible pre-code basis. They are related with binary oppositions of the Yin-Yang type and they give new opportunities to investigate evolution of the genetic code. The revealed fact of the relation between the genetic code and these genetic algebras is discussed in connection with the idea by Pythagoras: "All things are numbers". Simultaneously these genetic algebras can be utilized as the algebras of genetic operators in biological organisms. The described results are related with the problem of algebraization of bioinformatics. They take attention to the question: what is life from the viewpoint of algebra?; Comment: 27 pages...

Matrix genetics, part 4: cyclic changes of the genetic 8-dimensional Yin-Yang-algebras and the algebraic models of physiological cycles

Petoukhov, Sergey V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 16/09/2008
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46.03%
The article continues an analysis of the genetic 8-dimensional Yin-Yang-algebra. This algebra was revealed in a course of matrix researches of structures of the genetic code and it was described in the author's articles arXiv:0803.3330 and arXiv:0805.4692. The article presents data about many kinds of cyclic permutations of elements of the genetic code in the genetic (8x8)-matrix [C A; U G](3) of 64 triplets, where C, A, U, G are letters of the genetic alphabet. These cyclic permutations lead to such reorganizations of the matrix form of presentation of the initial genetic Yin-Yang-algebra that arisen matrices serve as matrix forms of presentations of new Yin-Yang-algebras as well. They are connected algorithmically with Hadamard matrices. The discovered existence of a hierarchy of the cyclic changes of types of genetic Yin-Yang-algebras allows thinking about new algebraic-genetic models of cyclic processes in inherited biological systems including models of cyclic metamorphoses of animals. These cycles of changes of the genetic 8-dimensional algebras and of their 8-dimensional numeric systems have many analogies with famous facts and doctrines of modern and ancient physiology, medicine, etc. This viewpoint proposes that the famous idea by Pythagoras (about organization of natural systems in accordance with harmony of numerical systems) should be combined with the idea of cyclic changes of Yin-Yang-numeric systems in considered cases. This second idea reminds of the ancient idea of cyclic changes in nature. From such algebraic-genetic viewpoint...

Geodynamo and mantle convection simulations on the Earth Simulator using the Yin-Yang grid

Kageyama, Akira; Yoshida, Masaki
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/06/2005
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46.03%
We have developed finite difference codes based on the Yin-Yang grid for the geodynamo simulation and the mantle convection simulation. The Yin-Yang grid is a kind of spherical overset grid that is composed of two identical component grids. The intrinsic simplicity of the mesh configuration of the Yin-Yang grid enables us to develop highly optimized simulation codes on massively parallel supercomputers. The Yin-Yang geodynamo code has achieved 15.2 Tflops with 4096 processors on the Earth Simulator. This represents 46% of the theoretical peak performance. The Yin-Yang mantle code has enabled us to carry out mantle convection simulations in realistic regimes with a Rayleigh number of $10^7$ including strongly temperature-dependent viscosity with spatial contrast up to $10^6$.; Comment: Plenary talk at SciDAC 2005