Microsatellite instability and mutations of E2F-4 in hepatocellular carcinoma from Korea

It has been suggested that genetic changes in cancers are related to genomi c instability. To evaluate a possible correlation between growth-regulatory genes and genomic instability in HCC, we investigated microsatellite insta bility and mutations of TGF-beta type II receptor (TGF-beta RII) and E2F-4 genes in each pair of tumor and surrounding nontumor liver tissues, collect ed from 19 patients with HCC. By the identification of mutations in six dif ferent genetic loci (D1S170, D2S123, D4S395, D13S126, D13S260, and D16S402) , one or more alterations in microsatellite markers were identified in 13/1 9 (68%) hepatocellular carcinoma specimens. When two repeated sequences of TGF-beta RII gene, poly(A)(10) tract in exon 8 and poly(GT)(3) tract in exo n 9. were analyzed by polymerase chain reaction-single strand conformationa l polymorphism, none of the 19 hepatocellular carcinoma specimens showed mu tations. When amplicons of poly(AGC)(13) tract of E2F-4 were analyzed by cl oning and automated sequencing, 5/19 (36%) hepatocellular carcinomas showed deletion mutation in one or two AGC repeats and such mutations were identi fied only among cases with microsatellite instability. These results sugges t that both microsatellite instability and mutations of E2F-4 occur commonl y in hepatocellular carcinoma and play an important role in hepatocarcinoge nesis. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.