Suppression of the Epidermal Growth Factor-like Domain 7 and Inhibition of Migration and Epithelial-Mesenchymal Transition in Human Pancreatic Cancer PANC-1 Cells

Background: Epidermal growth factor-like domain multiple 7 (EGFL7), a secreted protein specificallyexpressed by endothelial cells during embryogenesis, recently was identified as a critical gene in tumor metastasis.Epithelial-mesenchymal transition (EMT) was found to be closely related with tumor progression. Accordingly,it is important to investigate the migration and EMT change after knock-down of EGFL7 gene expression inhuman pancreatic cancer cells. Materials and
Methods: EGFL7 expression was firstly testified in 4 pancreaticcancer cell lines by real-time polymerase chain reaction (Real-time PCR) and western blot, and the highestexpression of EGFL7 was found in PANC-1 cell line. Then, PANC-1 cells transfected with small interferenceRNA (siRNA) of EGFL7 using plasmid vector were named si-PANC-1, while transfected with negative controlplasmid vector were called NC-PANC-1. Transwell assay was used to analyze the migration of PANC-1 cells.Real-time PCR and western blotting were used to detect the expression change of EGFL7 gene, EMT markerslike E-Cadherin, N-Cadherin, Vimentin, Fibronectin and transcription factors like snail, slug in PANC-1, NCPANC-1, and si-PANC-1 cells, respectively.
Results: After successful plasmid transfection, EGFL7 gene weredramatically knock-down by RNA interference in si-PANC-1 group. Meanwhile, migration ability decreasedsignificantly, compared with PANC-1 and NC-PANC-1 group. Meanwhile, the expression of epithelial phenotypemarker E-Cadherin increased and that of mesenchymal phenotype markers N-Cadherin, Vimentin, Fibronectindramatically decreased in si-PANC-1 group, indicating a reversion of EMT. Also, transcription factors snail andslug decreased significantly after RNA interference.
Conclusions: Current study suggested that highly-expressedEGFL7 promotes migration of PANC-1 cells and acts through transcription factors snail and slug to induceEMT, and further study is needed to confirm this issue.