PDX1, a key factor in pancreatic embryogenesis, can exhibit antimetastatic activity in pancreatic ductal adenocarcinoma

Abstract

Background: In cancer biology, metastasizing is one of the most poorly studied processes. Pancreatic ductal adenocarcinoma (PDAC) is characterized by early metastasis, which is the leading cause of death. The PDX1 protein is crucial for the development of cancer, and its low levels are characteristic of the most aggressive PDAC tumors. The PDX1 is a mediator of initiation and progression of PDAC. However, further studies are needed to elucidate the role of PDX1 in the cancer metastasis. Purpose: To confirm the hypothesis that PDX1 in PDAC plays suppressor role of epithelial– mesenchymal transition (EMT), and to study its possible ability to inhibit metastasis. Methods: A PDX1-overexpressing PDAC cell line was obtained by lentiviral transduction of PANC-1 cells. PDX1 overexpression was confirmed by RT-PCR and Western blotting. Effects of PDX1 ectopic expression on cell proliferation and motility were determined in PANC-1 cells using MTS, cell cycle analysis, transwell and wound-healing assay. EMT genes expression was analyzed in PDX1-overexpressing and Control PANC-1. Finally, the migration potential of pancreatic cancer cells expressing PDX1 was evaluated using a zebrafish embryo model. Results: The motility of human PDAC cells PANC-1 considerably decreased at ectopic expression of PDX1. The decreased expression of ZEB1, the key factor of EMT, and almost unchanged expression of the genes that characterize the epithelial state suggest a decrease in the EMT ability. Suppression of PDX1 expression by siRNA knockdown restored the PANC1 motility. Conclusion: The results obtained suggest a possible therapeutic use of PDX1 delivery into PDAC patients with a reduced or absent expression of PDX1 in the most aggressive tumors.