[The hyposensitization of oval cell to antiproliferative effect of transforming growth factor β1 by hepatitis B virus X gene].

Objective: To determine whether hepatitis B virus X (HBX) protein expression affect the oval cells' response to anti-proliferative effect of transforming growth factor β1 (TGFβ1) in oval cells.

Methods: Real-time PCR, Western blot analysis were performed to detect the expression of TGFβRII in HBX-transfected oval cells named HBX-EGFP-LE/6, and EGFP-LE/6, LE/6 control cells. In addition, exogenous TGFβ1 was added into all three oval cell lines, MTT assay was preformed to clarify different responses to the anti-proliferative effect of TGFβ1.

Results: The TGFβRII mRNA levels in LE/6 and EGFP-LE/6 cells were (10.2 ± 1.8) and (8.8 ± 0.9) folds of those in HBX-EGFP-LE/6 cells, the difference was significant (P < 0.05). HBX protein expression also reduced the protein levels of TGFβRII in HBX-EGFP-LE/6 oval cells, compared to the control cells. The MTT results exhibited that, after TGFβ1 addition, proliferative inhibition rate in the HBX-EGFP-LE/6 cells was 18.1% ± 1.5% while those in control cells were 42.2% ± 2.8% and 41.9% ± 5.0%, the difference was significant (P < 0.01).

Conclusion: HBX protein expression affects TGFβRII transcriptional activity and protein synthesis, and insensitive oval cells to anti-proliferative effect of TGFβ1.