Regulation of hMSH2 and hMLH1 expression in the human colon cancer cell line SW1116 by DNA methyltransferase 1.
Cancer Lett
; 233(1): 124-30, 2006 Feb 20.
Article
em En
| MEDLINE
| ID: mdl-16473673
ABSTRACT
Aberrant DNA methylation is now recognized as an important epigenetic alteration occurring early in human cancer. To directly study the role of DNA methyltransferase 1 (DNMT1) in the regulation of expression of tumor-related genes in human colon cancer cells, we stably transfected expression constructs containing sense or antisense DNMT1 into the human colon cancer cell line, SW1116. The expression level of mismatch repair genes (MMR), human mut-L homologue 1 (hMLH1) and human Mut S homologue 2 (hMSH2), was monitored by real-time RT-PCR. The methylation status of hMLH1 and hMSH2 promoters was determined by bisulfite modification and methylation-specific PCR (MSP). The protein levels of DNMT1, hMSH2 and hMLH1 were determined by Western analysis. The results show that DNMT1 protein expression was increased or decreased in transfected cell lines containing sense or antisense DNMT1 constructs, respectively. In cells expressing the sense DNMT1 construct, the expression of hMLH1 and hMSH2 was down-regulated through hypermethylation of their respective promoters. Furthermore, antisense DNMT1 expression induced promoter demethylation and up-regulated transcription of hMSH2 (P<0.05) and hMLH1 (P=0.064) in SW1116 cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
/
Proteínas de Transporte
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Regulação Neoplásica da Expressão Gênica
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Neoplasias do Colo
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DNA (Citosina-5-)-Metiltransferases
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Proteína 2 Homóloga a MutS
Limite:
Humans
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article