An angiopoietin-like protein 2 autocrine signaling promotes EMT during pancreatic ductal carcinogenesis

// Carmine Carbone 1 , Geny Piro 2 , Matteo Fassan 3 , Anna Tamburrino 1 , Maria Mihaela Mina 2 , Marco Zanotto 1 , Paul J Chiao 5 , Claudio Bassi 4,6 , Aldo Scarpa 3,6 , Giampaolo Tortora 2,5,6 and Davide Melisi 1,5,6 1 Digestive Molecular Clinical Oncology Research Unit, Università degli studi di Verona, Verona, Italy 2 Laboratory of Oncology and Molecular Therapy, Department of Medicine, Università degli studi di Verona, Verona, Italy 3 ARC-Net Research Centre and Department of Pathology, Diagnostics and Surgery, Università degli studi di Verona, Verona, Italy 4 Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA 5 Medical Oncology Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy 6 Pancreas Institute, Azienda Ospedaliera Universitaria Integrata, Verona, Italy Correspondence: Davide Melisi, email: // Keywords : ANGPTL2, EMT, pancreatic cancer, LILRB2 Received : June 26, 2014 Accepted : October 23, 2014 Published : October 24, 2014 Abstract The identification of the earliest molecular events responsible for the metastatic dissemination of pancreatic ductal adenocarcinoma (PDAC) remains critical for early detection, prevention, and treatment interventions. In this study, we hypothesized that an autocrine signaling between Angiopoietin-like Protein (ANGPTL)2 and its receptor leukocyte immunoglobulin-like receptor B2 (LILRB2) might be responsible for the epithelial-to-mesenchymal transition (EMT) and, the early metastatic behavior of cells in pancreatic preneoplastic lesions. We demonstrated that the sequential activation of KRAS, expression of HER2 and silencing of p16/p14 are sufficient to progressively and significantly increase the secretion of ANGPTL2, and the expression of LILRB2. Silencing the expression of ANGPTL2 reverted EMT and reduced migration in these cell lines. Blocking ANGPTL2 receptor LILRB2 in KRAS, and KRAS/HER2/p16p14shRNA LILRB2- expressing cells reduced ANGPTL2-induced cell proliferation and invasion. An increasingly significant overexpression of ANGPTL2 was observed in in a series of 68 different human PanIN and 27 PDAC lesions if compared with normal pancreatic parenchyma. These findings showed that the autocrine signaling of ANGPTL2 and its receptor LILRB2 plays key roles in sustaining EMT and the early metastatic behavior of cells in pancreatic preneoplastic lesions supporting the potential role of ANGPTL2 for early detection, metastasis prevention, and treatment in PDAC.