Epithelial-mesenchymal Transition And Cancer Stem Cells In Different Areas Of Pancreatic Ductal Adenocarcinoma

Background:Difference regarding epithelial-mesenchymal transition(EMT)and cancer stem cells(CSCs)within tumors has rarely been studied.The aim of the present study was to investigate the expression status of markers associated with EMT and CSCs in different areas of human pancreatic ductal adenocarcinoma(PDAC)and to explore the association with clinicopathological characteristics.Methods:The cancer mass of PDAC was averagely divided into three areas from the center to the periphery,i.e.the core,middle and periphery.Cancer tissues in three different areas and peritumoral non-cancerous tissues of PDAC were obtained from 20 patients.Commercially-available software for pathological image manipulation(Image Pro Plus 6.0)was used to quantify the results of immunohistochemical staining.The integral optical density(IOD)represented the expression level of CD44 as a marker of CSCs,and E-cadherin and N-cadherin to assess the degree of EMT.The clinical significance of the expression status of markers of CSCs and EMT in PDAC was analyzed.Results:The expression of CD44,E-cadherin and N-cadherin was significantly different between the PDAC tissues and peritumoral non-cancerous tissues(P<0.05).However,there were no significant differences in markers of EMT and CSCs among the core,middle and peripheral areas of PDAC(P>0.05).Moreover,high expression of CD44 and N-cadherin,together with low expression E-cadherin are related to lymph node metastasis and vascular invasion(P<0.05).There was a positive correlation between CD44 and N-cadherin(P<0.05),and a negative correlation was found between E-cadherin and both CD44 and N-cadherin(P<0.05).Conclusions:A high level of CD44 and N-cadherin expression and low expression of E-cadherin are associated with lymph node metastasis and vascular invasion in PDAC.Furthermore,CSC properties are closely related to the EMT program in PDAC.