Roles of the MEK1/2 and AKT pathways in CXCL12/CXCR4 induced cholangiocarcinoma cell invasion

AIM:To evaluate the expression of C-X-C motif chemokine receptor 4(CXCR4)and its signaling cascades,which were previously identified as a key factor for cancer cell progression and metastasis,in cholangiocarcinoma cell lines.METHODS:The expression of CXCR4 and its signaling cascades were determined in the cholangiocarcinoma cell lines(RMCCA1 and KKU100)by Western blotting.The invasion assays and the detection of actin polymerization were tested in these cholangiocarcinoma cells treated with CXC chemokine ligand-12(CXCL12).RESULTS:Expression of CXCR4 was detected in both cholangiocarcinoma cell lines and activation of CXCR4 with CXCL12 triggered the signaling via the extracellular signal-regulated kinase-1/2(ERK1/2)and phosphoinositide 3-kinase(PI3K)and induction of cholangiocarcinoma cell invasion,and displayed high levels of actin polymerization.Addition of CXCR4 inhibitor(AMD3100)abrogated CXCL12-induced phosphorylation of MEK1/2 and Akt in these cells.Moreover,treatment with MEK1/2 inhibitor(U0126)or PI3K inhibitor(LY294 002)also attenuated the effect of CXCL12-induced cholangiocarcinoma cell invasion.CONCLUSION:These results indicated that the activation of CXCR4 and its signaling pathways(MEK1/2 and Akt)are essential for CXCL12-induced cholangiocarcinoma cell invasion.This rises Implications on a potential role for the inhibition of CXCR4 or its signal cascades in the treatment of cholangiocarcinoma.

Prospective study of MMP7 serum levels in the diagnosis of cholangiocarcinoma

AIM: To determine whether the serum level of matrix metalloproteinase-7 (MMP7) has the potential to diagnosis cholangiocarcinoma from benign biliary tract diseases. METHODS: This study was performed according to the PRoBE (a prospective-specimen-collection, retrospectiveblinded-evaluation) design. A total of 187 patients with obstructive jaundice were consecutively enrolled. After the diagnostic status of these patients was ascertained, their levels of serum MMP7 were assayed and compared with serum carbohydrate antigen 19-9 (CA19-9). This was conducted in a blinded case (cholangiocarcinoma)control (benign biliary tract disease) setup. RESULTS: MMP7 and CA19-9 serum levels were significantly elevated in cholangiocarcinoma patients (P < 0.001). The area under the curve (AUC) from a receiver operating characteristic (ROC) curve analysis for thediagnosis of cholangiocarcinoma, using MMP7 was more accurate than CA19-9 (AUC = 0.84, 95% CI: 0.778-0.903 for MMP7 and AUC = 0.79, 95% CI: 0.708-0.868 for CA19-9). The sensitivity and specificity of serum MMP7 (cut-off value of 5.5 ng/mL) was 75% and 78%, respectively, while the sensitivity and specificity of serum CA19-9 (cut-off value of 100 U/mL) was 68% and 87%, respectively. CONCLUSION: Serum values of MMP7 and CA19-9 appear to be useful biomarkers for differentiating cholangiocarcinoma from benign biliary tract obstructive diseases.

Prognostic relevance of circulating CK19 mRNA in advanced malignant biliary tract diseases

AIM: To determine the role of circulating tumor cells (CTCs) in prediction of the overall survival of patients with advanced malignant biliary tract obstruction. METHODS: We investigated the prognostic value of CTCs by examining two markers, cytokeratin (CK) 19 and human telomerase reverse transcriptase (hTERT) mRNA, in 40 patients diagnosed with advanced malig- nant biliary tract diseases. Quantitative real-time re- verse transcription polymerase chain reaction was used to detect CK19 and hTERT mRNA in the peripheral blood of these patients. Overall survival was analyzed using the Kaplan-Meier method and Cox regression modeling.RESULTS: Positive CK19 and hTERT mRNA expression was detected in 45% and 60%, respectively, of the 40 patients. Univariable analysis indicated that positive CK19 mRNA expression was significantly associated with worse overall survival (P = 0.009). Multivariable analysis determined that positive CK19 mRNA expres- sion, patient's age and serum bilirubin were each inde- pendently associated with overall survival. CONCLUSION: CK19 mRNA expression levels in pe- ripheral blood appear to provide a valuable marker to predict the overall survival of patients with advanced malignant biliary tract obstruction.

Strong expression of CD133 is associated with increased cholangiocarcinoma progression

AIM:To determine the role of CD133 in cholangiocarcinoma progression. METHODS:CD133 protein expression was evaluated by immunohistochemistry in 34 cholangiocarcinoma specimens.In addition,proliferation,chemoresistance and invasive properties of CD133-enriched(CD133 + ) and CD133-depleted(CD133 )RMCCA1 cholangiocarcinoma cells were studied and compared. RESULTS:Strong CD133 expression was observed in 67.6%(23/34)of the cholangiocarcinoma specimens. Strong expression of CD133 was significantly associated with nodal metastasis(P=0.009)and positive surgical margin status(P=0.011).In the in vitro study, both the CD133 + and CD133 cells had similar proliferation abilities and resistance to chemotherapeutic drugs.However,the CD133 + cells had a higher invasive ability compared with CD133 cells. CONCLUSION:CD133+cells play an important role in the invasiveness of cholangiocarcinoma.Targeting of the CD133+cells may be a useful approach to improve treatment against cholangiocarcinoma.