Serrated polyps of the large intestine: a molecular study comparing sessile serrated adenomas and hyperplastic polyps.
Histopathology
; 55(2): 206-13, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-19694828
ABSTRACT
AIMS:
To compare the molecular profile of a series of sessile serrated adenomas (SSAs) and hyperplastic polyps (HPs), in order to distinguish these lesions, SSAs having a potential role in the genesis of serrated adenocarcinomas through a serrated pathway in which methylation plays a key role. METHODS ANDRESULTS:
Twelve HPs and sixteen SSAs of the right and left colon were investigated for microsatellite instability, DNA mismatch repair genes, p53, p16, and beta-catenin expression, MLH1 and p16 (CDKN2A) gene methylation, and KRAS and BRAF mutations. Both SSAs and HPs were microsatellite stable. MLH1 and MSH2 protein silencing, aberrant cytoplasmic expression and methylation of p16 were found to be exclusive to right-sided SSAs. The MLH1 promoter gene was frequently methylated in right-sided SSAs in contrast with HPs. Abnormal p53 and beta-catenin expression was present in both SSAs and HPs. BRAF and KRAS mutation were mutually exclusive, but KRAS mutation was present only in left-sided SSAs and HPs.CONCLUSIONS:
HPs and SSAs may be related lesions. However, at least right-sided SSAs differ from left-sided SSAs and HPs in the occurrence of MLH1 and p16 methylation, supporting the hypothesis that SSAs could be precursors of serrated adenocarcinomas.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Adenoma
/
Pólipos do Colo
Limite:
Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article