Hypomethylation of long interspersed nuclear element-1 (LINE-1) is associated with poor prognosis via activation of c-MET in hepatocellular carcinoma.
Ann Surg Oncol
; 21 Suppl 4: S729-35, 2014 Dec.
Article
em En
| MEDLINE
| ID: mdl-24992910
ABSTRACT
BACKGROUND:
Long interspersed nuclear element-1 (LINE-1) methylation status, representing global DNA methylation levels, is associated with patient prognosis in several types of cancer. This study was designed to examine the prognostic significance of LINE-1 methylation in patients with hepatocellular carcinoma (HCC) and the possible mechanisms related to oncogene activation.METHODS:
Seventy-five HCC patients who underwent hepatectomy between 2006 and 2012 were enrolled in this study. Quantitative pyrosequencing was performed to quantify the methylation level of three CpG sites in the LINE-1 promoter. Clinicopathological variables and prognosis were compared between LINE-1 hypo- and hypermethylation groups. LINE-1-inserted c-MET (L1-MET) gene expression and its correlation with LINE-1 methylation levels also were analyzed.RESULTS:
LINE-1 was significantly hypomethylated in tumor tissues compared with nontumor tissues (48.3 ± 12.2 % vs. 68.2 ± 2.0 %, respectively, p < 0.0001). LINE-1 hypomethylation was not associated with any clinicopathological factors in HCC patients, except sex (p < 0.05). However, patients with LINE-1 hypomethylation exhibited significantly poorer outcome, and multivariate analysis revealed that LINE-1 hypomethylation was an independent risk factor for overall survival (hazard ratio (HR) = 6.1, p = 0.031) and disease-free survival (HR = 2.34, p = 0.045). L1-MET expression was significantly higher in tumor tissues (p < 0.01). L1-MET expression levels were inversely correlated with LINE-1 methylation levels, and positively correlated with c-MET expression (p < 0.05). Furthermore, higher c-MET protein expression was observed in the LINE-1 hypomethylated tumor tissues compared with hypermethylated tumor tissues (p = 0.032).CONCLUSIONS:
LINE-1 hypomethylation is significantly associated with poor prognosis in patients with HCC, possibly due to activation of c-MET expression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Biomarcadores Tumorais
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Carcinoma Hepatocelular
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Metilação de DNA
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Proteínas Proto-Oncogênicas c-met
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Elementos Nucleotídeos Longos e Dispersos
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Neoplasias Hepáticas
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Aged
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Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Ann Surg Oncol
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Japão