BACKGROUND:Cholangiocarcinoma is a highly aggres- sive,fatal malignancy,which is resistant to all current therapeutic approaches.The recent elevation in the incidence of cholangiocarcinoma has highlighted the need for novel approaches targeting the molecular basis of its invasiveness.Previously we reconstructed a RhoC antisense eukaryotic expression vector and transfected it into a cholangiocarcinoma cell line(QBC939)by the lipofectamine method.This study was undertaken to determine the effect of the antisense RhoC gene on the proliferation and invasion capacity of QBC939. METHODS:Antisense RhoC cDNA was transfected into QBC939 with lipofectin 2000.The cell growth curve was constructed to determine the proliferation rate of cells;flow cytometry was used to analyze cell cycle changes of the tumor cells;and a Boyden chamber was used to assess the invasive ability of the cells before and after gene transfection. RESULTS:After the antisense RhoC cDNA was transfected, the number of colonies formed was significantly lower than that in the other two groups(54±8 vs.91±11 vs.90± 9,P<0.05)so was the number of the cells which crossed to the lower surface of the matrigel-coater filters(36±6 vs.96± 12 vs.95±7,P<0.05).There was also a higher percentage of transfected cells in G1 phase than in the other two groups (52.5%vs.43.4%vs.43.7%). CONCLUSION:The antisense RhoC gene can suppress the capacities of proliferation and invasion in a cholangiocarcinoma cell line in vitro. BACKGROUND: Cholangiocarcinoma is a highly aggres- sive, fatal malignancy, which is resistant to all current therapeutic approaches. The recent elevation in the incidence of cholangiocarcinoma has highlighted the need for novel approaches targeting the molecular basis of its invasiveness. Previously we reconstructed a RhoC antisense eukaryotic expression vector and transfected it into a cholangiocarcinoma cell line (QBC939) by the lipofectamine method. This study was undertaken to determine the effect of the antisense RhoC gene on the proliferation and invasion capacity of QBC939. METHODS: Antisense RhoC cDNA was transfected into QBC939 with lipofectin 2000. The cell growth curve was constructed to determine the proliferation rate of cells; flow cytometry was used to analyze cell cycle changes of the tumor cells; and a Boyden chamber was used to assess the invasive ability of the cells before and after gene transfection. RESULTS: After the antisense RhoC cDNA was transfected, the number of colonies was was lower than that in the other two groups (54 ± 8 vs. 91 ± 11 vs. 90 ± 9, P <0.05) was the number of the cells which crossed to the lower surface of the matrigel-coater filters ( 36 ± 6 vs.96 ± 12 vs.95 ± 7, P <0.05) .here was also a higher percentage of transfected cells in G1 phase than in the other two groups (52.5% vs.43.4% vs.43.7%). CONCLUSION: The antisense RhoC gene can suppress the capacitations of proliferation and invasion in a cholangiocarcinoma cell line in vitro.