Genomic instability, frequently observed in cancers, has two types: chromosomal instability, CIN and microsatellite instability, MIN. It is reported that aberration of spindle assembly check-point (SAC) and mutation of TP53 gene is frequently observed in CIN, while precise mechanism of how CIN occur is not known. To discover the significance of DNA aneuploidy and its mechanism, we analyzed DNA ploidy status in gastric cancer and colorectal cancer clinical samples. We also analyzed MSI status, a marker for MIN, in the same samples and found that DNA aneuploidy and MSI (+) have reverse correlation. The expression of BUBR1, one of the important factors in SAC, was analyzed in gastric cancer sample. High expression of BUBR1 had significant relationship with DNA aneuploidy. To introduce the significance of DNA aneuploidy in gastro-intestinal cancers, we will discuss about DNA ploidy status, MSI status and the expression of BUBR1 in this study.
