A novel promoter-associated non-coding small RNA paGLI1 recruits FUS/P65 to transactivate GLI1 gene expression and promotes infiltrating glioma progression

Glioma-associated oncogene homolog 1 (GLI1) is a core component of the Hedgehog (HH) signalling pathway and is a transcription activator of numerous oncogenes, such as SOX9, VEGFA, BCL2, and CDK2. The complex regulation of GLI1 involves numerous pathways and molecules, including HH-dependent and independent, epigenetic and post-transcriptional mechanisms. Here, we report the discovery, characterization and function of a novel sense promoter-associated ncRNA, paGLI1 that is overexpressed in infiltrating glioma. We show that paGLI1 promotes GLI1 gene transcription through binding to and recruitment of the transcription factor complex FUS/P65 by interacting with paGLI1 DNA sequence. This interaction facilitates FUS/P65 binding to the GLI1 promoter to activate GLI1 transcription and hence its downstream oncogenes, which results in enhancement of glioma cell proliferation and invasiveness. Importantly, over-expression of paGLI1 is a significant unfavorable prognosticator for both disease-specific and progression-free survival in glioma patients, with relative risks being 2.932 (95% confidence interval: 1.280 to 6.713) (P < 0.05) and 2.284 (95% confidence interval: 1.051 to 4.966) (P < 0.05), respectively. The novel paGLI1/FUS/P65 regulatory mechanisms play important roles in infiltrating glioma progression and may serve as potential targets for future therapeutics.