Objective      To investigate the effect of ten-eleven-translocation 1 (TET1) a 5-methylcytosin hydroxylase

on the hepatocytic differentiation of oval cells in liver regeneration.       Methods      A liver regeneration model was established by gavage of 2-acetylaminofluorine (2-AAF) and surgical resection of 70% liver in SD rats. The expression of TET1 was analyzed by RT-PCR and Western blotting at 3

6

9

12

and 15 d after liver resection. Primary rat oval cells were isolated by c

ollagenase perfusion

purified by density-gradient centrifugation and stained for OV6 detection by immunofluorescence assay. WB-F344 oval cells were treated by dexamethasone 1.0×10

-7

mol/L and DMSO 1.5%

with or without a mixture of cytokines including SCF 20 μg/L

HGF 10 μg/L

and EGF 10 μg/L

for 7 d. Cell differentiation was examined by detection of morphological changes and differentiation maker such as ALB. The expressions of TET1 were further determined.       Results      A large number of primary rat oval cells were obtained

with 80% OV6

+

oval cells. After induced differentiation for 7 d

oval cells showed a shape change from round to polygonal. Furthermore

induced differentiation resulted in reduce of TET1 expression (

P

0.01) and dramatically increased expression of ALB (

P

0.01)

suggesting oval cells underwent hepatocytic differentiation.       Conclusion      TET1 participates in the proliferation of oval cells and liver regeneration possibly.