145P - ZEB1 and ZEB2 mediate pancreatic fibroblast induced epithelial-to mesenchymal transition (EMT) in pancreatic cancer

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Basic Science
Pancreatic Cancer
Presenter Laura Visa
Authors L. Visa1, E. Samper2, M. Rickmann2, A. Postigo3, E. Sanchez-Tilo3, L. Fernandez-Cruz4, J. Maurel5, X. Molero6, E..C. Vaquero2
  • 1Department Medical Oncology, Hospital Clinic Barcelona, 08036 - Barcelona/ES
  • 2Gastroenterology Department, Hospital Clinic, 08036 - Barcelona/ES
  • 3Oncology And Hematology, IDIBAPS, 08035 - Barcelona/ES
  • 4Surgical Deparment, Hospital Clinic, 08035 - Barcelona/ES
  • 5Medical Oncology, Hospital Clinic i Provincial, Barcelona/ES
  • 6Gastroenterologist, Hospital Vall Hebron, 08026 - Barcelona/ES

Abstract

EMT renders neoplastic cancer cells the ability to migrate and to invade distant organs. The hallmark of EMT is the loss of E-cadherin, which is a prerequisite for epithelial tumor cell invasion. In pancreatic cancer, loss of tumor E-cadherin is an independent predictor of poor outcome.AIMS: To analyze the effect of pancreatic fibroblasts (PF) on inducing EMT in pancreatic cancer cells and to identify the transcription factors (Snail, Slug, ZEB1, ZEB2) that mediate EMT process.

Methods

Human PFs were isolated from human pancreatic specimens obtained from chronic pancreatitis and from unaffected margins of pancreatic adenocarcinoma and serous cistoadenoma. PF were cultured until complete cellular activation, as assessed by expression of a-smooth muscle actin, vimentin and fibronectin. Human pancreatic cancer cells Panc-1 were exposed to PF conditioned medium (PF-CM) and EMT analyzed by cell morphology, migration, and E-cadherin expression (quantitative RT-PCR and immunoblot). Gene expression of Snail, Slug, ZEB1, and ZEB2 was analyzed by quantitative RT-PCR, and their activity modulated by siRNA.

Results

Conditioned media from all types of activated PFs induced EMT changes in Panc-1 cells, as shown by 1) morphological transition from cobblestone shaped to fibroblast-like cells, 2) stimulation of cell migration, and 3) E-cadherin down–regulation; mRNA expression of Snail transiently increased at 30 min after exposure to PF returning to basal levels afterwards; mRNA levels of ZEB1 were not up-regulated upon exposure to PF-CM. However, ZEB1 protein greatly accumulated after 48h incubation with PF-CM, suggesting that PF prevent ZEB1 degradation in Panc-1 cells. Combined RNA downregulation of ZEB1 and ZEB2, but not of Snail and/or Slug, suppressed E-cadherin repression induced by PF.

Conclusion

Activated PFs promote the invasive phenotype of pancreatic cancer cells through ZEB1 and ZEB2 activation.

Disclosure

All authors have declared no conflicts of interest.