HEPATOCELLULAR CARCINOMAS INFECTED WITH THE NOVEL TT DNA VIRUS LACK VIRAL INTEGRATION

A novel DNA virus designated TT virus (TTV) was cloned from a patient with posttransfusion hepatitis and is thought to be a new hepatitis vi rus. At present, hepatitis B virus (HBV) and hepatitis C virus (HCV) a re known to induce hepatocellular carcinoma (HCC). But, actually, in J apan approximately 5 to 10% of HCCs are in HEV-negative and HCV-negati ve (NBNC) patients. In order to study the possible role of TTV in hepa tocarcinogenesis, we investigated the frequency of the TTV genome in l iver tissue of 20 HCC patients. As a result, 3 of 8 NBNC HCC patients and 5 of 12 HBV- or HCV-associated HCC patients were TTV positive, and TTV was shown not to be specific for NBNC HCC. For all TTV-positive p atients, we also confirmed that the TTV genome was not integrated into host hepatocyte DNA. (C) 1998 Academic Press.