Probes for LONG

BACKGROUND:

Long noncoding RNAs (lncRNAs) were recently found to be key regulators of biological functions and associated with human diseases. Thus far, the roles of lncRNAs in inflammatory bowel disease (IBD) remain unknown. We aimed to determine whether lncRNAs are associated with IBD and regulate epithelial cell physiology.

METHODS:

lncRNAs microarray and quantitative RT-PCR were performed on 60 sigmoid colon biopsies from patients with active ulcerative colitis (UC) and relevant controls. Localization of lncRNAs was detected by in situ hybridization and on subcellular RNA. The boundaries of BC012900 were assessed by 5' and 3'-rapid amplification of cDNA ends. Apoptosis and proliferation assays were performed on BC012900-expressing construct or siRNA-transfected cells.

RESULTS:

We identified 329 lncRNAs with increased and 126 lncRNAs with decreased expression in active UC tissues compared with normal control tissues, including the most significantly upregulated (BC012900, AK001903, and AK023330) and downregulated (BC029135, CDKN2B-AS1, and BC062296) transcripts. We found that most of the lncRNAs are localized to the nucleus. In particular, BC012900 expression was significantly increased in active UC and stimulated by cytokines and pathogenic molecules. Furthermore, BC012900 overexpression in epithelial cells results in a significant inhibition of cell proliferation and an increased susceptibility to apoptosis, which differ from its adjacent gene DUSP4.

CONCLUSIONS:

Multiple lncRNAs are differentially expressed in IBD and play a role in regulating cellular physiology. Our results indicate that lncRNAs may be integral modulators of intestinal inflammation associated with IBD and represent novel targets for future therapeutics and diagnostic marker development.

Functionality of the non-coding transcripts encoded by the human genome is the coveted goal of the modern genomics research. While commonly relied on the classical methods of forward genetics, integration of different genomics datasets in a global Systems Biology fashion presents a more productive avenue of achieving this very complex aim. Here we report application of a Systems Biology-based approach to dissect functionality of a newly identified vast class of very long intergenic non-coding (vlinc) RNAs. Using highly quantitative FANTOM5 CAGE dataset, we show that these RNAs could be grouped into 1542 novel human genes based on analysis of insulators that we show here indeed function as genomic barrier elements. We show that vlincRNAs genes likely function in cis to activate nearby genes. This effect while most pronounced in closely spaced vlincRNA-gene pairs can be detected over relatively large genomic distances. Furthermore, we identified 101 vlincRNA genes likely involved in early embryogenesis based on patterns of their expression and regulation. We also found another 109 such genes potentially involved in cellular functions also happening at early stages of development such as proliferation, migration and apoptosis. Overall, we show that Systems Biology-based methods have great promise for functional annotation of non-coding RNAs.