Recurrence of WHV integration in the b3n locus in woodchuck hepatocellular carcinoma.

Frequent occurrence of woodchuck hepatitis virus DNA (WHV DNA) integration into or in proximity to myc oncogenes and in the win locus of cellular genome in woodchuck hepatocellular carcinomas (HCC) has been described by several authors. We report a further cellular locus as a recurrent target for WHV integration in woodchuck HCCs. A WHV DNA integration and its cellular flanking regions were cloned from a HCC developed in a chronically WHV-infected woodchuck. Sequence analysis showed integration of rearranged C, PreS1, and 5' truncated X regions of the WHV genome, located in a cellular locus previously described for WHV integration in another woodchuck HCC. The two integration sites are only about 0.5 kb apart. In addition to Alu-like repeats and a gag-like coding region, previously described, we found several features of MAR (matrix attachment region) chromosomal sequences in the normal cellular locus, leading us to predict that part of it might be a previously unrecognized MAR.