The role of the transcription factor ZEB1 in epithelial-mesenchymal transition and progression of pancreatic carcinoma

Abstract

Introduction: The epithelial-mesenchymal transition (EMT) describes the transition of epithelial cells from the epithelial to the mesenchymal phenotype, leading to aquisition of motility, invasiveness and stem cell properties, and is regulated by multiple transcription factors. EMT has been implicated in physiological processes during embryonic development and wound healing as well as in cancer progression. Materials and Methods: In vitro: Gene expression analysis of the human pancreatic carcinoma cell lines PANC-1, MIAPaCa-2, BXPC-3 and HPAF-2 was performed by RT-PCR and immunofluorescence. Transient and stable knock-down of ZEB1 was done by transfection of si- and sh-RNA constructs and confirmed by RT-PCR and immunofluorescence. For quantification of motility, invasiveness and anoikis-resistence, scratch-assay, matrigel-transmigration chambers and anoikis-induction by poly HEMA was used. In vivo: an orthotopic nude mouse models was implemented and local and distant tumor dissemination was assessed using an established score. Results: The expression of ZEB1 and E-Cadherin showed a good correlation with the known phenotype and in vivo aggressiveness of the cell lines. Knock-down of ZEB1 led to reexpression of E-Cadherin in PANC-1 cells. In transient and stable knock-down experiments, a role of ZEB1 for motility, invasiveness and anoikis-resistence of PANC-1 and MIAPaCa-2 cells could be demonstrated. Stable knock-down led to a reduced tumor dissemination in vivo. Conclusion: The expression of ZEB1 correlates with the aggressiveness of human pancreatic carcinoma cells lines in vivo. Knockdown of ZEB1 leads to reduced tumor cell motility, invasiveness and avoikis resistance in vitro and inhibition of tumor cell dissemination in vivo. This demonstrates an important role of ZEB1 in the tumor progression of human pancreatic carcinoma.