Identification of long non coding RNAs regulated by oncogenic KRAS in pancretic cancer

Abstract

Activating mutations in KRAS are very frequent in Pancreatic Ductal Adenocarcinomas (PDACs), but different approaches to directly target Ras for therapy failed in clinical trials. An alternative route for blocking RAS-driven oncogenic pathways is to target downstream effectors of RAS involved in promoting the oncogenic phenotype. Long non-coding RNAs (lncRNAs) regulate gene expression through epigenetic mechanisms that affect chromatin structure and are important mediators of the oncogenic process. However, lncRNAs involved in oncogenic KRAS-induced malignant transformation remain unknown. The goal of this project is to identify lncRNAs that play an important role in the KRAS-induced malignant phenotype. We hypothesize that KRAS-induced cellular transformation alters the expression pattern of lncRNAs, altering their function and, thereby, contributing to malignant transformation. To test this hypothesis we will compare the expression profile of lncRNAs obtained by DNA microarray of pancreatic isogenic lines in presence/absence of the oncogenic form of KRAS with the expression profile obtained by RNAseq of clinical samples of PDAC. This analysis will, not only identify the lncRNAs that are regulated by KRAS, but also the lncRNAs more likely involved in promoting malignant behavior in PDAC patients. Next, we will validate the differential expression of the identified lncRNAs and will confirm they are regulated by KRAS in pancreatic cancer cell lines. Finally, based on the correlation of expression of the validated lncRNAs with the presence of KRAS mutations in pancreatic tumors, as well as on the described function of these lncRNAs, we will choose one differentially expressed lncRNA to perform functional analysis, which will be carried out by modulating the expression levels of the chosen lncRNA in KRAS-dependent human pancreatic cancer cells, followed by functional cell-based assays in vitro and in vivo. This project is expected to contribute to a better understanding of the molecular mechanisms activated by KRAS oncoprotein in pancreatic cancer, whereas at the same time, it is expected to provide the knowledge required for the development of new anti-tumoral therapies. (AU)