ABSTRACT: Cancer cells are thought to possess immune evasion properties due to FasL overexpression in many types of human tumors. In the present study, we set out to investigate the role of MAPK-ERK pathway in 67-kDa laminin receptor induced FasL expression and FasL-mediated apoptosis in human cholangiocarcinoma cells.
The expression of FasL and its promoter activity in cultured cholangiocarcinoma cells were examined after treatment with laminin or transfection with plasmids containing siRNA targeted to 67-kDa laminin receptor. The effects of MAPK-ERK cascade inhibitor and c-Myc inhibition by siRNA on 67-kDa laminin receptor-induced FasL expression were determined. Apoptosis assay was performed to analyze the apoptosis of lymphocytes cocultured with cholangiocarcinoma cells treated with or without MAPK-ERK cascade inhibitor.
Our results revealed that the specific MAPK-ERK cascade inhibitor, PD98059, significantly attenuated phosphorylation of c-Myc on Ser-62 and FasL upregulation in QBC-939 cells and these cells showed decreased cytotoxicity against Fas-sensitive Jurkat T cells. A luciferase reporter assay revealed that FasL promoter activity was significantly reduced in cells treated with PD98059 or transfected with c-Myc siRNA.
Based on these results, we conclude that 67LR induces FasL expression and cytotoxicity against Fas-sensitive Jurkat T cells in human cholangiocarcinoma cells through the phosphorylation of c-Myc on Ser-62 and the subsequent activation of the FasL promoter through the ERK pathway.
Digestive Diseases and Sciences 10/2010; 55(10):2844-52. · 2.12 Impact Factor
ABSTRACT: To explore the role of hepatitis C virus core protein on the infiltration and metastasis of cholangiocarcinoma tissues.
From January 2001 to November 2006, 34 patients with cholangiocarcinoma who had intact follow-up data randomly were chosen. The expression of HCVc protein, epithelium markers and mesenchymal markers in cholangiocarcinoma tissues were examined by SP methods of immunohistochemistry, clinical-pathological data were recorded and analyzed.
The positive expression rate was observed in 47.1% for HCVc protein, 50% for N-cadherin, 44.1% for Vimentin, 55.9% for Fibronectin and the decreased expression rate was E-cadherin for 55.9%, alpha-catenin for 70.6%, beta-catenin for 55.9%. The positive expression of HCVc protein was associated with the decreased expression of E-cadherin, alpha-catenin and the positive expression of N-cadherin, Vimentin, Fibronectin (chi(2) = 4.480, 4.163, 4.250, 7.438, 12.260, P < 0.05). A positive-correlation between the expression of HCVc protein and metastasis of lymph nodes and other organs were found (chi(2) = 5.708, 4.163, P < 0.05).
HCVc protein might promote cholangiocarcinoma tissues' infiltration and metastasis by inducing it's epithelial-mesenchymal transition.
Zhonghua wai ke za zhi [Chinese journal of surgery] 11/2007; 45(21):1491-3.
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.
Zhonghua yi xue za zhi 10/2004; 84(19):1642-4.