TET family proteins and 5-hydroxymethylcytosine in esophageal squamous cell carcinoma.
Oncotarget
; 6(27): 23372-82, 2015 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-26093090
ABSTRACT
Mammalian DNA is epigenetically marked by 5'-cytosine methylation (5-methylcytosine [5-mC]). The Ten-eleven translocation (TET) enzymes (TET1, TET2, and TET3) are implicated in DNA demethylation, through dioxygenase activity that converts 5-mC to 5-hydroxymethylcytosine (5-hmC). Although decreased TET is reportedly associated with decreased 5-hmC levels in various cancers, functions of 5-hmC and TET expression in esophageal squamous cell carcinoma (ESCC) are unclear. We used ELISA and immunohistochemistry tests to analyze 5-hmC status in ESCC tissues, RT-qPCR to analyze TET family mRNA expression in normal and tumor tissues, and pyrosequencing to quantify LINE-1 (i.e., global DNA methylation) levels. ELISA and immunohistochemical testing showed 5-hmC levels were significantly lower in ESCC than in paired normal tissues (P < 0.0001). TET2 expression was significantly lower in ESCCs than paired normal tissues (P < 0.0001), and significantly associated with 5-hmC levels in ESCCs (P = 0.003, r = 0.33). 5-hmC levels were also significantly associated with LINE-1 methylation level (P = 0.0002, r = 0.39). Patients with low 5-hmC levels had shorter overall survival than those with higher levels, although not significantly so (P = 0.084). In conclusion, 5-hmC expression was decreased in ESCC tissues, and was associated with TET2 expression level. TET2 reduction and subsequent 5-hmC loss might affect ESCC development.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Esofágicas
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Carcinoma de Células Escamosas
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Proteínas Proto-Oncogênicas
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Citosina
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Proteínas de Ligação a DNA
Tipo de estudo:
Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article