A deletion polymorphism of the ACE gene is associated with serum ACE activity and increased risk for CAD in the Japanese.

Loss of heterozygosity (LOH) and microsatellite instability (MSI) commonly occur in colorectal carcinomas. However, the role of these genetic alterations in determining DNA ploidy status of tumors (diploid, aneuploid and multiploid) remains unclear. In the present study, we attempted to clarify the relationship between genetic alterations and DNA ploidy status. Crypt isolation coupled with DNA cytometric sorting and polymerase chain reaction assay (17 microsatellite markers) were used to study allelic losses and MSI in 59 colorectal carcinomas (diploid, 15; aneuploid, 10 and multiploid, 34). Of the 15 diploid carcinomas, 6 exhibited MSI in which allelic losses were rarely found. The other 9 diploid tumors mostly exhibited allelic losses, but none displayed MSI status. Whereas allelic losses frequently occurred in the aneuploid carcinomas and the aneuploid populations of multiploid carcinomas, they were rarely detected in the diploid populations of multiploid carcinomas. MSI status was not observed in aneuploid carcinomas nor in either population of multiploid carcinomas. Although multiploid carcinomas genetically resemble aneuploid carcinomas in the expression of the severe LOH phenotype, the genetic alterations seen in the diploid populations of multiploid carcinomas may differ from those of diploid carcinomas. Furthermore, all diploid, aneuploid and both the diploid and aneuploid fractions of the multiploid tumors that were non‐MSI exhibited a high rate of LOH, suggesting that LOH is independent of the tumor's ploidy status. Int. J. Cancer 88:614–619, 2000. © 2000 Wiley‐Liss, Inc.

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DNA heterogeneity of colorectal carcinomas has been investigated by flow cytometry, most studies have focused on the clinical usefulness of DNA ploidy analysis. Since cancers consist of predominant subclones with proliferative advantage due to clonal expansion, we attempted to analyse the clonal expansion of colorectal carcinomas within a tumour by measuring DNA ploidy. The DNA ploidy and heterogeneity of multiple fresh samples obtained from 164 colorectal adenocarcinomas were analysed by flow cytometry. Each tumour was divided into an average of six specimens, which were analysed separately. For 146 of the tumours (89%) at least one DNA aneuploid population was found within the cancer tissue examined. DNA multiploidy was detected in 26 cases (17.8%) among the cancers with aneuploidy. Based on the DNA index (DI), hypertriploid aneuploidy (1.7

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