ABERRATION OF GENOMIC DNA IN ASSOCIATION WITH HUMAN HEPATOCELLULAR CARCINOMAS DETECTED BY 2-DIMENSIONAL GEL ANALYSIS

Alterations of genomic DNAs in primary hepatocellular carcinomas (HCCs ) were examined by restriction landmark genomic scanning (I. Hatada et al., Proc. Natl. Acad. Sci. USA, 88: 9523-9527, 1991) which is a 2-di mensional gel analysis that allows detection of deletion, amplificatio n, or other rearrangements of genomic DNA. Sixteen HCC samples togethe r with their normal counterparts were tested in this manner. Each HCC sample was micromanipulated to minimize possible carryover from non-ma lignant cells. DNAs from HCCs and their normal counterparts were cleav ed with the restriction enzyme NotI, end labeled with P-32, and size f ractionated by 2-dimensional electrophoresis using HinfI as the second cleavage enzyme. The resulting spots (about 2000) in HCC samples were compared with their normal counterparts. Five spots were more intense in 10-14 of the 16 HCCs (63-88%). The intensity of several spots was reduced to about half, suggesting the loss of one of two alleles. Some of these decreases were observed frequently in different HCC samples, whereas others were sporadic. Sixty of these spots reproducibly decre ased in >2 cases, with 27 showing a decrease in >50% of the informativ e cases. The highest incidence was observed in 14 of 16 samples (88%). No significant correlations were observed between these changes in sp ots and hepatitis B virus or hepatitis B virus infection. The use of l andmarks that show a reproducible increase or decrease in intensity is discussed in conjunction with future studies of genomic alterations i nherent in HCC.