Pancreatic cancer is characterized by extensive metastasis. EMT plasticity plays a critical role in tumor progression and metastasis by maintaining the transition between EMT and MET states. Our aim is to understand the molecular events regulating metastasis and EMT plasticity in pancreatic cancer.
The interactions between a cancer promoting zinc transporter ZIP4, a zinc dependent EMT transcriptional factor ZEB1, a co-activator YAP1, and integrin α3 (ITGA3) were examined in human pancreatic cancer cells, clinical specimens, spontaneous mouse models (KPC and KPCZ) and orthotopic xenografts, and 3D spheroid and organoid models. Correlations between ZIP4, miR-373, and its downstream targets were assessed by RNA in situ hybridization and IHC staining. The transcriptional regulation of ZEB1, YAP1, ITGA3 by ZIP4 was determined by ChIP, Co-IP and luciferase reporter assays.
The Hippo pathway effector YAP1 is a potent transcriptional co-activator and forms a complex with ZEB1 to activate ITGA3 transcription through the YAP1/TEAD binding sites in human pancreatic cancer cells and KPC derived mouse cells. ZIP4 upregulated YAP1 expression via activation of miR-373 and inhibition of the YAP1 repressor LATS2. Furthermore, upregulation of ZIP4 promoted EMT plasticity, cell adhesion, spheroid formation and organogenesis both in human pancreatic cancer cells, 3D spheroid model, xenograft model, and spontaneous mouse models (KPC and KPCZ) through ZEB1/YAP1-ITGA3 signaling axis.
We demonstrated that ZIP4 activates ZEB1 and YAP1 through distinct mechanisms. The ZIP4-miR-373-LATS2-ZEB1/YAP1-ITGA3 signaling axis has a significant impact on pancreatic cancer metastasis and EMT plasticity.
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