Identification and characterization of the gene expression profiles for protein coding and non-coding RNAs of pancreatic ductal adenocarcinomas

This is an open-access article distributed under the terms of the Creative Commons Attribution License.Significant advances have been achieved in recent years in the identification of the genetic and the molecular alterations of pancreatic ductal adenocarcinoma (PDAC). Despite this, at present the understanding of the precise mechanisms involved in the development and malignant transformation of PDAC remain relatively limited. Here, we evaluated for the first time, the molecular heterogeneity of PDAC tumors, through simultaneous assessment of the gene expression profile (GEP) for both coding and non-coding genes of tumor samples from 27 consecutive PDAC patients. Overall, we identified a common GEP for all PDAC tumors, characterized by an increased expression of genes involved in PDAC cell proliferation, local invasion and metastatic capacity, together with a significant alteration of the early steps of the cellular immune response. At the same time, we confirm and extend on previous observations about the genetic complexity of PDAC tumors as revealed by the demonstration of two clearly distinct and unique GEPs (e.g. epithelial-like vs. mesenchymal-like) reflecting the alteration of different signaling pathways involved in the oncogenesis and progression of these tumors. Our results also highlight the potential role of the immune system microenvironment in these tumors, with potential diagnostic and therapeutic implications.This work has been partially supported by grants from the Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS861/A/13), RTICC from the Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Madrid, Spain (RD06/0020/0035-FEDER; RD12/0036/0048-FEDER), Fundación Memoria de Don Samuel Solórzano Barruso, Salamanca, Spain (FS/13-2012 and FS/16-2013). JM Sayagués is supported by grant CP05/00321 from the Ministerio de Ciencia e Innovación, Madrid, Spain.Peer Reviewe