scholarly journals Promoter methylation of glutathione S-transferase π1 and multidrug resistance gene 1 in bronchioloalveolar carcinoma and its correlation with DNA methyltransferase 1 expression

Cancer ◽  
2009 ◽  
Vol 115 (14) ◽  
pp. 3222-3232 ◽  
Author(s):  
Peng Gao ◽  
Xi Yang ◽  
Yu-Wen Xue ◽  
Xiao-Fang Zhang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Resistance Gene ◽  
Promoter Methylation ◽  
Dna Methyltransferase ◽  
Bronchioloalveolar Carcinoma ◽  
Dna Methyltransferase 1 ◽  
Glutathione S Transferase ◽  
Multidrug Resistance Gene ◽  
Methyltransferase 1

scholarly journals DNA methyltransferase 1 expression and promoter methylation of E-cadherin in mucoepidermoid carcinoma

Cancer ◽  
2005 ◽  
Vol 104 (5) ◽  
pp. 1013-1021 ◽  
Author(s):  
Yi-Shing Shieh ◽  
Shine-Gwo Shiah ◽  
Hao-Hsuan Jeng ◽  
Herng-Sheng Lee ◽  
Cheng-Wen Wu ◽  
...  
Keyword(s):  
Promoter Methylation ◽  
Mucoepidermoid Carcinoma ◽  
Dna Methyltransferase ◽  
Dna Methyltransferase 1 ◽  
E Cadherin ◽  
Methyltransferase 1

scholarly journals Expression and purification of the first nucleotide-binding domain and linker region of human multidrug resistance gene product: comparison of fusions to glutathione S-transferase, thioredoxin and maltose-binding protein

1999 ◽  
Vol 338 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Changsen WANG ◽  
Ariel F. CASTRO ◽  
Denise M. WILKES ◽  
Guillermo A. ALTENBERG
Keyword(s):  
Multidrug Resistance ◽  
Resistance Gene ◽  
Gene Product ◽  
Nucleotide Binding ◽  
Maltose Binding Protein ◽  
Nucleotide Binding Domain ◽  
Expression And Purification ◽  
Glutathione S Transferase ◽  
Multidrug Resistance Gene ◽  
Linker Region

Many membrane proteins that belong to the ATP-binding cassette (ABC) superfamily are clinically important, including the cystic fibrosis transmembrane conductance regulator, the sulphonylurea receptor and P-glycoprotein (multidrug resistance gene product; MDR1). These proteins contain two multispanning transmembrane domains, each followed by one nucleotide-binding domain (NBD) and a linker region distal to the first NBD. ATP hydrolysis by the NBDs is critical for ABC protein function; the linker region seems to have a regulatory role. Previous attempts to express soluble NBDs and/or linker regions without detergent solubilization, or to purify NBDs at high yields as soluble fusion proteins, have been unsuccessful. Here we present a system for the expression in Escherichia coli of the first NBD of MDR1 followed by its linker region (NBD1MLD). A comparison of the expressions of NBD1MLD fused to glutathione S-transferase, thioredoxin and maltose-binding protein (MBP) shows that a high level of expression in the soluble fraction (approx. 8% of total E. coli protein) can be achieved only for MBP–NBD1MLD. The addition of a proteolytic thrombin site just proximal to the N-terminal end of NBD1MLD allows the cleavage of NBD1MLD from MBP, which can be easily purified with retention of its ATPase activity. In summary, success was obtained only when using an MBP fusion protein vector containing a thrombin proteolytic site between MBP and NBD1MLD. The approach described here could be generally applicable to solving the problems of expression and purification of NBDs/linker regions of ABC proteins.

scholarly journals Induction of altered epigenetic regulation of the hepatic glucocorticoid receptor in the offspring of rats fed a protein-restricted diet during pregnancy suggests that reduced DNA methyltransferase-1 expression is involved in impaired DNA methylation and changes in histone modifications

2007 ◽  
Vol 97 (6) ◽  
pp. 1064-1073 ◽  
Author(s):  
Karen A. Lillycrop ◽  
Jo L. Slater-Jefferies ◽  
Mark A. Hanson ◽  
Keith M. Godfrey ◽  
Alan A. Jackson ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Histone Modifications ◽  
Epigenetic Regulation ◽  
Promoter Methylation ◽  
Dna Methyltransferase ◽  
Metabolic Phenotype ◽  
Dna Methyltransferase 1 ◽  
Gene Promoters ◽  
Dnmt1 Expression ◽  
Methyltransferase 1

Prenatal nutritional constraint induces an altered metabolic phenotype in the offspring which in humans confers an increased risk of non-communicable disease. Feeding a protein-restricted (PR) diet to pregnant rats causes hypomethylation of specific gene promoters in the offspring and alters the phenotype. We investigated how altered epigenetic regulation of the hepatic glucocorticoid receptor (GR) 110 promoter is induced in the offspring. Rats were fed a control (180 g casein/kg) or a PR (90 g casein/kg) diet throughout pregnancy, and chow during lactation. Offspring were killed at postnatal day 34 (n 5 per maternal dietary group). Methylation-sensitive PCR showed that GR110 promoter methylation was 33 % lower (P < 0·001) and GR expression 84 % higher (P < 0·05) in the PR offspring. Reverse transcription–PCR showed that DNA methyltransferase-1 (Dnmt1) expression was 17 % lower (P < 0·05) in PR offspring, while Dnmt3a/b and methyl binding domain protein-2 expression was not altered. Thus hypomethylation of the GR110 promoter may result from lower capacity to methylate hemimethylated DNA during mitosis. Histone modifications which facilitate transcription were increased at the GR110 promoter (147–921 %, P < 0·001), while those that suppress methylation were decreased (54 %, P < 0·01) or similar to controls. In human umbilical cord (n 15), there was a 2-fold difference between the highest and lowest level of GR1-CTotal promoter methylation. Dnmt1, but not Dnmt3a, expression predicted 49 % (P = 0·003) of the variation in GR1-CTotal promoter methylation. These findings suggest that induction in the offspring of altered epigenetic regulation of the hepatic GR110 promoter, and hence metabolic phenotype, may be due to reduced Dnmt1 expression.

scholarly journals Precipitous Release of Methyl-CpG Binding Protein 2 and Histone Deacetylase 1 from the Methylated Human Multidrug Resistance Gene (MDR1) on Activation

2002 ◽  
Vol 22 (6) ◽  
pp. 1844-1857 ◽  
Author(s):  
Assam El-Osta ◽  
Phillip Kantharidis ◽  
John R. Zalcberg ◽  
Alan P. Wolffe
Keyword(s):  
Multidrug Resistance ◽  
Resistance Gene ◽  
Histone Deacetylase ◽  
Dna Methyltransferase ◽  
Binding Protein ◽  
Trichostatin A ◽  
Methylation Status ◽  
Dna Demethylation ◽  
Multidrug Resistance Gene ◽  
Histone Deacetylase 1

ABSTRACT Overexpression of the human multidrug resistance gene 1 (MDR1) is a negative prognostic factor in leukemia. Despite intense efforts to characterize the gene at the molecular level, little is known about the genetic events that switch on gene expression in P-glycoprotein-negative cells. Recent studies have shown that the transcriptional competence of MDR1 is often closely associated with DNA methylation. Chromatin remodeling and modification targeted by the recognition of methylated DNA provide a dominant mechanism for transcriptional repression. Consistent with this epigenetic model, interference with DNA methyltransferase and histone deacetylase activity alone or in combination can reactivate silent genes. In the present study, we used chromatin immunoprecipitation to monitor the molecular events involved in the activation and repression of MDR1. Inhibitors of DNA methyltransferase (5-azacytidine [5aC]) and histone deacetylase (trichostatin A [TSA]) were used to examine gene transcription, promoter methylation status, and the chromatin determinants associated with the MDR1 promoter. We have established that methyl-CpG binding protein 2 (MeCP2) is involved in methylation-dependent silencing of human MDR1 in cells that lack the known transcriptional repressors MBD2 and MBD3. In the repressed state the MDR1 promoter is methylated and assembled into chromatin enriched with MeCP2 and deacetylated histone. TSA induced significant acetylation of histones H3 and H4 but did not activate transcription. 5aC induced DNA demethylation, leading to the release of MeCP2, promoter acetylation, and partial relief of repression. MDR1 expression was significantly increased following combined 5aC and TSA treatments. Inhibition of histone deacetylase is not an overriding mechanism in the reactivation of methylated MDR1. Our results provide us with a clearer understanding of the molecular mechanism necessary for repression of MDR1.

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