Promoter-Associated RNAs Regulate HSPC152 Gene Expression in Malignant Melanoma

Potential of long non-coding RNAs as a therapeutic target and molecular markers in glioblastoma pathogenesis

Glioblastoma (GB) is by far the most hostile type of malignant tumor that primarily affects the brain and spine, derived from star-shaped glial cells that are astrocytes and oligodendrocytes. Despite of significant efforts in recent years in glioblastoma research, the clinical efficacy of existing medical intervention is still limited and very few potential diagnostic markers are available. Long non-coding RNAs (lncRNAs) that lacks protein-coding capabilities were previously thought to be "junk sequences" in mammalian genomes are quite indispensible epigenetic regulators that can positively or negatively regulate gene expression and nuclear architecture, with significant roles in the initiation and development of tumors. Nevertheless, the precise mechanism of these distortedly expressed lncRNAs in glioblastoma pathogenesis is not yet fully understood. Since the advent of high-throughput sequencing technologies, more and more research have elucidated that lncRNAs are one of the most promising prognostic biomarkers and therapeutic targets for glioblastoma. In this paper, I briefly outlined the existing findings of lncRNAs. And also summarizes the profiles of different lncRNAs that have been broadly classified in glioblastoma research, with emphasis on both their prognostic and therapeutic values.

Profiling the epigenetic interplay of lncRNA RUNXOR and oncogenic RUNX1 in breast cancer cells by gene in situ cis-activation

RUNX1 is frequently mutated as chromosomal translocations in a variety of hematological malignancies. Recent studies show that RUNX1 is also mutated somatically in many solid tumors. We have recently identified a 260 kb un-spliced intragenic overlapping long noncoding RNA RUNXOR in the RUNX1 locus, yet its role as an epigenetic regulator in tumors remains to be characterized. To delineate this RUNXOR-RUNX1 regulatory interplay in breast cancer cells, we devised a novel "gene in situ cis-activation" approach to activate the endogenous RUNXOR gene. We found that the in situ activation of RUNXOR lncRNA upregulated RUNX1 in cis from the P1 promoter. The preferred activation of the P1 promoter caused a shift to the RUNX1c isoform expression. Using a chromatin conformation capture (3C) approach, we showed that RUNXOR lncRNA epigenetically activated the RUNX1 P1 promoter in cis by altering the local chromatin structure. The binding of RUNXOR lncRNA triggered DNA demethylation and induced active histone modification markers in the P1 CpG island. Changes in RUNX1 isoform composition correlated with a trend to cell cycle arrest at G0/G1, although cell proliferation rate, apoptosis, and migration ability were not significantly changed. Our results reveal an underlying epigenetic mechanism by which the lncRNA regulates in cis the RUNX1 promoter usage in breast cancer cells, thereby shedding light on potential genetic therapies in malignancies in which RUNX1 loss-of-function mutations frequently occur.