Effect of down regulation of laminin receptor on urokinase-type plasminogen activator expression in human bile duct carcinoma cells

Abstract

To investigate the effect of antisense oligonucleotide (AS-OD) of laminin receptor (LNR) on urokinase-type plasminogen activator (u-PA) expression in human bile duct carcinoma cells. Bile duct carcinoma cells of QBC939 line were cultured. Compounds of lipofectAMINE and AS-OD phosphorothioate of LNR of the concentrations of 3, 6, and 12 micromol/L respectively were prepared and then transfected into the QBC939 cells. Sense oligodeoxynucleotide (S-OD) of LNR and blank vector were used as controls. After culture of 48 hours, flow cytometry was used to detect the protein expression of LNR and the u-PA mRNA expression was detected by reverse-transcriptase polymerase chain reaction (RT-PCR). Cell invasion was examined by culture plate with Transwell microporous film before and after transfection. Flow cytometry showed down-regulation of LNR protein expression in the cells transfected with AS-OD dose-dependently. The LNR protein expression of the cells transfected with AS-OD of the concentration of 6 micromol/L was down-regulated by over 25% in comparison with those of the blank vector group and S-OD group (both P < 0.05). RT-PCR showed that the u-PA mRNA expression of the AS-OD 6 micromol/L group was down-regulated by 30% in comparison with the 2 control groups. The number of migrating cells in the AS-OD group was 78 +/- 6, significantly lower than those in the S-OD group (105 +/- 11), and blank vector group (101 +/- 7), both P < 0.05. The expression of laminin receptor in the bile duct carcinoma cells is related with the expression of u-PA gene expression. Inhibition of LNR expression decreases the u-PA gene expression, suggesting that LNR plays an important role in the invasion and metastasis of bile duct carcinoma.