Expression of the c-myc protooncogene product in cells infected with the hepatitis delta virus

✍ Scribed by Gianfranco Tappero; Gioacchino Natoli; Giovanni Anfossi; Floriano Rosina; Francesco Negro; Antonina Smedile; Ferruccio Bonino; Alberto Angeli; Robert H. Purcell; Professor Mario Rizzetto; Massimo Levrero

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 756 KB
• Volume: 20
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840200502

✦ Synopsis

Orbassano, Clinica Medica, University '(La Sapienza, " 001 00 Rome, and 4Department of Gastroenterology, Ospedale

The intrahepatic accumulation of the c-myc protooncogene product was observed on immunofluorescence in each of six patients with chronic hepatitis delta virus infection who exhibited the hepatitis D antigen in their livers. The c-myc product was stained in the same nuclei that contained the hepatitis D antigen. C-myc was not observed in acute hepatitis D or in cases of chronic hepatitis delta virus infection without expression of the hepatitis D antigen. The protooncogene product was detected in only 1 of 32 viral and nonviral liver disorders unrelated to hepatitis delta virus. To confirm these observations, we transfected HBsAg-positive (PCL/PRF/5) and HBsAgnegative (HepG2) transformed liver cell lines with a plasmid containing a hepatitis delta virus cDNA trimer under the control of the SV40 early enhancerlpromoter sequences. Whereas baseline c-myc expression was barely detectable in mock-transfected PLC/PRF/5 or HepG2 cells, strong c-myc nuclear fluorescence was observed when these same cells were transfected with the hepatitis D antigen expression vector. Similar results were obtained after infection of HeLa cells with a recombinant vaccinia virus expressing the hepatitis D antigen. Detection of c-myc mRNA sequences by means of in situ hybridization suggested that the c-myc product accumulation was not due to increased amounts of its mRNA. The c-myc protein accumulates selectively in the livers of patients with chronic hepatitis delta virus infection and in the same nuclei that contain the hepatitis D antigen. The expression of c-myc in hepatitis D antigencontaining cells does not require the presence of hepatitis B virus infection. (HEPATOLOGY 1994;20: 1109-1114.)