FREQUENT REARRANGEMENTS AT MINISATELLITE LOCI D1S7 (1P33-35), D7S22 (7Q36-TER) AND D12S11 (12Q24.3-TER) IN HEPATITIS-B VIRUS-POSITIVE HEPATOCELLULAR CARCINOMAS FROM THAI PATIENTS

Primary hepatocellular carcinoma (HCC) is one of the most common cance rs in Thailand; chronic infection with hepatitis B virus (HBV) is ende mic and represents a major risk factor for the development of this can cer, Several mechanisms for HBV-related hepatocarcinogenesis have been proposed, among them a direct role of HBV in the promotion of genetic recombination leading to chromosomal alterations, Minisatellite DNA s equences are hypervariable regions dispersed throughout the genome whi ch are susceptible to genetic recombination events, In the present stu dy, somatic rearrangements affecting minisatellite sequences were exam ined in a total of 26 HCC from Thai patients, Multilocus DNA fingerpri nting using probes 33.15 and 33.6 detected rearrangements in 11 and 12 HCC, respectively, all of them carrying integrated HBV DNA, The frequ ency of rearranged bands was calculated for each probe based on the to tal number of rearrangements observed in the 26 tumours and the total number of bands revealed by DNA fingerprinting in the non-tumour DNA. With each probe a total of 23 rearrangements was observed, yielding re arrangement frequencies of 3.7% and 4.2% for the 33.15 and 33.6 minisa tellite families, respectively, To test for possible clustering of the se rearrangements at specific loci, we used minisatellite locus-specif ic probes previously cloned from 33.15 and 33.6, Minisatellites locate d at 1p33-35, 7q36-ter and 12q24.3-ter were shown to be frequently aff ected by rearrangement events in this series of HBV-positive HCC. Freq uent rearrangements at minisatellite locus D7S22 (7q36-ter) in HBV-pos itive human HCC have not been reported so far. (C) 1997 Wiley-Liss, In c.