Detection And Correlation Of Circulating Tumor Cells With Epithelial-mesenchymal Transition-related Phenotypes In Pancreatic Cancer

[Objective]1.To study the difference of circulating tumor cell(CTCs)between healthy person and patient with pancreatic ductal adenocarcinoma.2.To assess the significance of CTCs in clinicopathologic factors and prognosis of PDAC.3.To investigate the dynamic change of Epithelial-Mesenchymal Transition(EMT)related CTCs phenotype during the treatment.4.To study EMT in PDAC through comparing the difference of epithelial and mesenchymal markers in in primary tumor,peripheral blood CTCs and metastatic lymph nodes.[Methods]1.We conducted microfluidic platform to analyze the significance of EMT related CTCs in clinicopathologic factors of PDAC,and monitor the dynamic change of EMT phenotype during the treatment through immunofluorescence staining of E-cadherin and Vimentin in CTCs.2.E-cadherin and Vimentin were measured in primary tumor and metastatic lymph nodes through immunohistochemistry(IHC)with patients diagnosed as pancreatic ductal adenocarcinoma.We evaluated the EMT during the metastasis of PDAC by the difference of epithelial and mesenchymal markers in in primary tumor,peripheral blood CTCs and metastatic lymph nodes.[Results]1.The first part of study included 56 individuals(46 patients with PDAC and 10 healthy persons).The cutoff value between healthy person and patient with PDAC was 8.5/2ml.The cutoff value between patient with non-metastatic PDAC and metastatic PDAC was 49.5/2ml.Significant differences were found in the numbers of CTCs and mensenchymal CTCs regarding to the differentiation,carcinoma cell embolus and TNM stage.When the numbers of CTCs exceeded 47/2ml(total),11/2ml(epithelial),17/2ml(epithelial and mesenchymal)and 35/2ml(mesenchymal),the prognosis would be dismal.There was no relationship between CTCs and surgery while the numbers of CTCs decreased after chemotherapy.It was noticed that the numbers of CTCs did not change significantly after two cycles of chemotherapy.2.The second part of study included 35 individuals.After IHC staining,we found that the expression of E-cadherin increased and the expression of Vimentin decreased in primary tumor,comparing the para-carcinoma tissue(P = 0.000 and P = 0.003).The expressions of E-cadherin and Vimentin were not significantly associate with clinicopathologic factors.The ratio of highly expressed E-cadherin in primary tumor was 68.6%and highly expressed Vimentin in primary tumor was 37.1%,while the ratio of CTCs expressed Vimentin was 78.6%.The ratio of mesenchymal CTCs increased during the chemotherapy.[Conclusions]1.There were significant difference between the numbers of CTCs and the differentiation,carcinoma cell embolus and TNM stage.It reflected the severity of PD AC and had prognostic significance in the patients with PDAC.2.The epithelial and mesenchymal composition exhibited dynamic changes during the process of metastasis.CTCs exhibited dynamic changes in epithelial and mesenchymal composition during the chemotherapy.