Abstract:Objective:To study the effect of transfection with antisense DNMT3b gene eukaryotic expression plasmid on the growth of human cholangiocarcinoma cell line QBC939, and to explore the role of DNMT3b in the cholangiocarcinoma tumorigenesis. Methods:The constructed antisense DNMT3b gene eukaryotic expression plasmid was transfected into QBC939 cells using liposome. The expression level of DNMT3b protein was detected by Western blot after stable transfection. The growth curves of transfected cells and un-transfected cells were observed by MTT method respectively. The cell proliferation ability was also observed by the test of colony formation in soft agar. The alterations of the cell cycle and the apoptosis rate were detected by FCM. Results:Following the transfection, the protein level of DNMT3b decreased significantly; transfection with antisense DNMT3b gene eukaryotic expression plasmid did not affect the cell growth curve of QBC939, and did not decrease the cell colony formation rate (P＝0.717); transfection with antisense DNMT3b gene also did not result in cell cycle alterations or induce cell apoptosis (P＝0.089). Conclusions:Transfection with antisense DNMT3b gene eukaryotic expression plasmid can down-regulate the expression level of DNMT3b in QBC939. It can not affect the growth and proliferation of human cholangiocarcinoma cell line QBC939, nor alter the cell cycle and induce cell apoptosis.