Intermediate methylation epigenotype and its correlation to XXXX mutation in conventional colorectal adenoma.

@entity984 @entity5 @entity189 @entity817 @entity14 @entity652
A subset of @entity14 shows significant accumulation of aberrant promoter methylation. Previously, we developed two groups of methylation markers that classified @entity14 into three epigenotypes: i) high-, ii) intermediate-, and iii) low-methylation epigenotypes. High-methylation epigenotype, with methylation of both group 1 and group 2 markers, correlates to @entity817 -mutation((+)). Intermediate-methylation epigenotype, with methylation of group 2 markers, but not group 1, correlates to @entity984 -mutation((+)). To gain insight into epigenotype development in @entity14 , especially intermediate-methylation epigenotype and its correlation to @entity984 -mutation((+)) in @entity652 , we analyzed methylation levels of group 1 and group 2 markers quantitatively by matrix assisted laser desorption ionization-time of flight mass spectrometry, in 51 @entity652 , 13 aberrant crypt foci, and 26 normal mucosa samples, and we compared them to 149 previously analyzed @entity14 samples. Three serrated @entity652 were all @entity817 -mutation((+)), showing great methylation of group 1 and group 2 markers, thus high-methylation epigenotype. Forty-eight conventional @entity652 were not methylated in group 1 markers and were classified into two clusters with higher and lower methylation of group 2 markers, thus into intermediate- and low-methylation epigenotypes, respectively. @entity652 with intermediate-methylation epigenotype correlated to @entity984 -mutation((+)). Methylation levels of group 2 markers in @entity652 were higher than aberrant crypt foci and normal samples, but similar to @entity5 . These data suggested that epigenotype development occur at an earlier stage than @entity189 formation, and already be completed at the @entity652 stage. Intermediate methylation epigenotype and its correlation to @entity984 -mutation((+)) were developed in conventional @entity652 .
