Trans-activation of epidermal growth factor receptor gene by the hepatitis B virus X-gene product.
The expression of the cellular gene coding for the epidermal growth factor (EGF) receptor (EGF-R) was assayed in the presence of hepatitis B virus (HBV) gene expression under different experimental conditions in human hepatoma-derived cells. First, transfection experiments of the well-differentiated HepG2 human hepatoma cell line using different expression vectors of the HBV X-region demonstrated that the X-gene product is capable of inducing EGF-R gene overexpression; in addition, by using a stable in vitro expression system for HBV, it was shown that EGF-R gene expression in these cells is greater than in the uninfected parent cells, and that this results in a three-fold increase in 125I-EGF binding. Finally, a CAT-expression assay was performed, indicating that regulatory regions of the EGF-R-gene are target sequences for X-protein trans-activation.
Menzo
S
S
Institute of Microbiology, University of Ancona, Italy.
Clementi
M
M
Alfani
E
E
Bagnarelli
P
P
Iacovacci
S
S
Manzin
A
A
Dandri
M
M
Natoli
G
G
Levrero
M
M
Carloni
G
G
D006528:Carcinoma, Hepatocellular / Q000235:genetics; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000096:biosynthesis / Q000235:genetics*; D005822:Genetic Vectors / Q000235:genetics; D006515:Hepatitis B virus / Q000254:growth & development; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics*; D015533:Transcriptional Activation; D014162:Transfection / Q000235:genetics; D014407:Tumor Cells, Cultured; D054334:Viral Regulatory and Accessory Proteins; D014779:Virus Replication
D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D004815:Epidermal Growth Factor; D015500:Chloramphenicol O-Acetyltransferase; D066246:ErbB Receptors