Detection of hepatitis B virus genome in hepatocellular carcinoma tissues with PCR-in situ hybridization

The detection is described of hepatitis B virus (HBV)-DNA in preserved hepa tocellular carcinoma tissues, which were derived from 14 HBV-seropositive p atients. Detection was by polymerase chain reaction (PCR) amplification of the target sequence, followed by specific localization of the PCR product w ith in situ hybridization. FISH (PCR-in situ hybridization) yielded strong positive signals in most of the tumor tissues despite very low copy numbers of chromosome-integrated HBV genome, whereas no signal was detected in con trol samples, indicating that the signals were specific for HBV. Positive s ignals were sometimes detected in cirrhotic nodules surrounding the tumor r egions, indicating that HBV had infected non-transformed liver cells. HBV-D NA was detected in both nucleus and cytoplasm in some specimens, possibly r epresenting HBV at different stages of the life cycle. In one case, a gradi ent of viral DNA was revealed, with the highest DNA signal centered at the site of viral antigen expression. Taken together, FISH is shown to be a hig hly sensitive molecular detection method that is capable of detecting the p resence of a low copy number viral genome in situ. (C) 1999 Elsevier Scienc e B.V. All rights reserved.