Identification of REST-Regulated Molecular Circuitries and Targets Exploitable for hGSCs-Targeted Therapies

Glioblastoma (GBM) represents the most frequent and lethal cancer affecting the central nervous system for which no cure is currently available. The presence of Glioma Stem Cells (GSCs) has been proposed to be at the root of therapeutic failures due to their intrinsic abilities of escaping common treatments and relapsing the pathology. Thus, advances in therapeutic options may derive from the manipulation of mechanisms controlling the GSCs self-renewal, survival and functions. RE1-Silencing Transcription Factor (REST) is a master repressor of neuronal developmental programme in non-neuronal lineages, recently described as a main actor in the maintenance of the GSCs’ tumorigenic competence as its knockdown strongly impairs GSCs stemness both in vitro and in vivo. However, REST is critical for restraining neuronal cellular identity in various tissues, so that a targeted therapy to this transcriptional repressor is likely to present numerous side effects. Here, by taking advantage of a Tet-on system for the manipulation of REST expression in both human GSCs and Neural Stem Cell lines (hNSCs), we performed a transcriptomic profiling analysis in order to identify novel tumour-specific REST-regulated functions and molecular targets. Our analyses confirmed the previously reported roles of REST in neural tissues and enlightened novel REST functions in hGSCs, including the regulation of alternative hGSCs identity/state. Finally, analysis of hGSC-specific REST-regulated genes in GBM patients’ dataset revealed an inverse correlation with glioma aggressiveness, thus establishing a hGSC REST score that might provide a useful prognostic tool.