We studied the relationships between genetic and epigenetic alterations in gastrointestinal cancer by integrating DNA copy number changes determined by arbitrarily primed PCR (AP-PCR) with DNA methylation variations estimated by methylation-sensitive amplified fragment length polymorphism (MS-AFLP). We analyzed about 100 different chromosomal regions by AP-PCR and over 150 random CpG loci by MS-AFLP in human colon and gastric carcinomas. DNA hypomethylation and hypermethylation alterations distributed gradually and increased with cancer patient age, in contrast with the age-independent genomic alterations. Increased DNA hypomethylation and hypermethylation correlated with increased genomic damage, but only hypomethylation was highly significant in multivariate analyses. We conclude that age-dependent accumulation of DNA demethylation precedes diploidy loss in a significant subset of gastrointestinal cancers.

UMIN000001396.

With the strategy introduced here it is possible to record intraoperative VEPs in almost all patients except in those with severe visual dysfunction. In some patients, postoperative visual deterioration can be avoided or minimized by intraoperative VEP recording. All patients without an intraoperative decrease in the VEP amplitude were without severe postoperative deterioration in visual function, suggesting that intraoperative VEP monitoring may contribute to prevent postoperative visual dysfunction.

The findings of this study suggest that the monitoring method that is introduced here is safe and reliable for detecting intraoperative BFI in the AChA.