MicroRNA profiling of pancreatic ductal adenocarcinoma (PDAC) reveals signature expression related to lymph node metastasis

// Moran Lemberger 1, 2, * , Shelly Loewenstein 1, 2, * , Nir Lubezky 1, 2, 3 , Eran Nizri 1, 2, 3 , Metsada Pasmanik-Chor 4 , Eli Barazovsky 5 , Joseph M. Klausner 2, 3, 6 and Guy Lahat 1, 2, 3 1 Laboratory of Surgical Oncology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel 2 Division of Surgery, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel 3 Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel 4 Bioinformatics Unit, Tel Aviv University, Tel Aviv, Israel 5 Institute of Pathology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel 6 The Nikolas and Elizabeth Shlezak Cathedra for Experimental Surgery, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel * These authors have contributed equally to this work Correspondence to: Guy Lahat, email: guyla@tlvmc.gov.il Keywords: microRNA; pancreatic cancer; lymph node metastasis; epithelial-to-mesenchymal transition (EMT); invasion Received: June 29, 2018     Accepted: February 22, 2019     Published: April 05, 2019 ABSTRACT Lymph node (LN) metastasis occurs frequently in pancreatic ductal adenocarcinoma (PDAC), representing an advanced disease stage and independently predicting patient survival. Current nodal staging is inadequate preoperatively and even less so postoperatively, and molecular biomarkers are needed to improve prognostication and selection of therapy. Recent data have suggested important roles of miRNAs in PDAC tumorigenesis and progression. The aim of the present study was to identify miRNA expression signature for nodal spread in PDAC patients. Using PDAC human tissue specimens, we identified 39 miRNAs which were differently expressed in LN positive compared to LN negative PDAC samples. Of them, six miRNAs have been reported to play a role in cancer invasion and metastasis. A high versus low six- miRNA signature score was predictive of LN metastasis in the PDAC validation cohort. We demonstrated a similar expression pattern of four out of the six miRNAs in the plasma of PDAC patients. The results of our in-vitro studies revealed that miR-141 and miR-720 are involved in the process of epithelial to mesenchymal-transition in PDAC. These miRNAs significantly inhibited in vitro proliferation, migration and invasion of PDAC cells as evidence by gain- and loss- of function studies, specifically, via ZEB-1 and TWIST1 transcription factors, as well as through the activation of the MAP4K4/JNK signaling pathway.