<正>Objective:To investigate whether the rabbit serum after radiofrequency ablation to liver tumor can induce mesenchymal stem cells （MSCs） differentiating into hepatocyte-like cells in order to find a new source and culture process for repairing liver injury.Methods:A tumor piece of 1 mm×1 mm×1 mm was transplanted into a tunnel at right liver of rabbits.The model of liver tumor was established after 2-3 weeks.The serum was collected from rabbits 72 h after being subjected to radiofrequency ablation of the liver tumor.Mesenchymal stem cells were isolated from rabbit bone marrow and cultured in DMEM containing autologous rabbit serum.Three kinds of media （L-DMEM） were tested respectively:①containing 10% fetal calf serum （FCS）;②containing 30% rabbit autologous serum after radiofrequency ablation of the liver tumor （ASRF）;③containing 30% rabbit autologous serum （AS）.MSCs were cultured on 12-well plates until passage 2 and examined under the light and electron microscopy at indicted intervals. The expression of albumin and CK18 was detected using immunofluorescence to identify the characteristics of differentiated cells.Results:MSCs performed differently in the presence of fetal calf serum

rabbit autologous serum and rabbit autologous serum after radiofrequency ablation of the liver tumor.Induced by the serum after radiofrequency ablation to liver tumor for 7 d

the spindle-shaped MSCs turned into round shaped and resembled hepatocyte-like cells. The reactions were not found in MSCs cultured in FCS and AS groups.After induction for 14 d

slender microvilli

cell-cell junction structure and cholangiole emerged

and the differentiated cells expressed albumin and CK18.All those could not been observed in 10% FCS and 30% autologous serum groups.Conclusion:Mesenchymal stem cells differentiate into hepatocyte-like cells in the serum after radiofrequency ablation of liver tumor

providing us a potential cell source and culture process for clinical application in liver injury repairing.