[Regulation of hepatitis C virus core protein on the activity of signal transducers and activators of transcription 3].
OBJECTIVE
To investigate the regulation of hepatitis C virus (HCV) core protein on the activity of signal transducers and activators of transcription 3 (stat3).


METHODS
A cell line expressing stable HCV core protein-QSG7701-core was constructed by transfecting the pcDNA3. 1-core (expressing HCV core protein) into the human immortalized hepatocyte line QSG7701. The phosphorylation and DNA binding activity of stat3 were detected by immunocytochemistry, Western blot, and electrophoretic mobility shift assay (EMSA).


RESULTS
The expression level of phosphorylated stat3 in QSG7701-core cells was significantly lower than that in QSG7701-pcDNA3. 1 cells and untransfected QSG7701 cells, but there were no significant differences in the expression levels of total stat3 among the 3 groups. The positive signal of phosphorylated stat3 in nucleus of QSG7701-core cells was obviously weaker than that in QSG7701-pcDNA3. 1 cells and untransfected QSG7701 cells. EMSA showed that DNA binding activity of stat3 in QSG7701-core cells significantly decreased.


CONCLUSIONS
The expressionof HCV core protein in human hepatocyte line may suppress the phosphorylation and DNA binding activity of stat3, which may be one of the causes for resistance against interferon.
Feng
De-yun
DY
Department of Pathology, Basic Medical College, China. dyfeng743@sohu.com
Li
Bo
B
Zheng
Hui
H
Cheng
Rui-xue
RX
Cao
Ya
Y
D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D006801:Humans; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D014758:Viral Core Proteins / Q000096:biosynthesis* / Q000235:genetics
D004268:DNA-Binding Proteins; D050796:STAT3 Transcription Factor; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus