C-HA-RAS POLYMORPHISM IN PATIENTS WITH HEPATOCELLULAR-CARCINOMA - COMPARISON OF HEALTHY-SUBJECTS AND ALCOHOLIC PATIENTS WITH CIRRHOSIS

It has been observed that certain rare alleles of the c-Ha-ras gene oc cur more frequently in patients with certain malignant tumors than in healthy individuals, suggesting that these alleles may serve as marker s for particular types of cancer. In this study, we compared the restr iction fragment length polymorphism at the c-Ha-ras gene locus in 40 p atients with cirrhosis and hepatocelluIar carcinoma with that in 39 pa tients with cirrhosis and in 42 normal subjects, all of Caucasian orig in. Southern blotting of leukocyte DNA from the above patients, after digestion with either BamHI or AvaII, revealed the presence of allele fragments of different sizes, corresponding to 4 common alleles and 3 rare alleles. The occurrence of the 3 rare alleles was not significant ly different in the 3 populations studied On the other hand, 2 of the common alleles, a3 (P < 0.01) and a4 (P < 0.03), were found at a signi ficantly higher frequency in patients with cancer than in the 2 other groups. These results suggest that, in hepatocellular carcinoma, there is no increase in the frequency of occurrence of the rare alleles of the c-Na-ras, but that the distribution of the common alleles may be m odified.