Tag Archives: lncrna
It is a great surprise that the genomes of mammals and other eukaryotes harbor many thousands of long noncoding RNAs (lncRNAs). Although these long noncoding transcripts were once considered to be simply transcriptional noise or cloning artifacts, multiple studies have suggested that lncRNAs are emerging as new players in diverse human diseases, especially in cancer, and that the molecular mechanisms of lncRNAs need to be elucidated.
More recently, evidence has begun to accumulate describing the complex post-transcriptional regulation in which lncRNAs are involved. It was reported that lncRNAs can be implicated in degradation, translation, pre-messenger RNA (mRNA) splicing, and protein activities and even as microRNAs (miRNAs) sponges in both a sequence-dependent and sequence-independent manner. In this review, the authors present an updated vision of lncRNAs and summarize the mechanism of post-transcriptional regulation by lncRNAs, providing new insight into the functional cellular roles that they may play in human diseases, with a particular focus on cancers.
- Shi X, Sun M, Wu Y, Yao Y, Liu H, Wu G, Yuan D, Song Y. (2015) Post-transcriptional regulation of long noncoding RNAs in cancer. Tumour Biol [Epub ahead of print]. [abstract]
A wiki-style database hopes to serve as an online encyclopedia of lncRNA by and for the scientific community.
Scientists have set up a long non-coding RNA (lncRNA) database aimed at harnessing the collective knowledge of the scientific community. This study has been published in Nucleic Acids Research.
LncRNAs are RNAs that do not code for proteins but are nonetheless actively transcribed in human genome. In recent years, it has been recognized that they perform significant roles in a large variety of biological processes. The dysregulation of lncRNA expression is highly correlated with human cancer, neurological disorders, and many other human diseases.
Long noncoding RNAs (lncRNAs) do not code for proteins but function as RNAs. Because the functions of an RNA rely on either its sequence or secondary structure, lncRNAs should be folded at least as strongly as messenger RNAs (mRNAs), which serve as messengers for translation and are generally thought to lack secondary structure-dependent RNA-level functions. Contrary to this prediction, analysis of genome-wide experimental data of human RNA folding reveals that lncRNAs are substantially less folded than mRNAs even after the control of expression level and GC%, although both lncRNAs and mRNAs are more strongly folded than expected by chance. In contrast to mRNAs, lncRNAs show neither the positive correlation between folding strength and expression level nor the negative correlation between folding strength and evolutionary rate. These and other results support that, while RNA folding undoubtedly plays a role in RNA biology, it is also important in translation and/or protein biology.
- Yang J, Zhang J. (2014) Human long noncoding RNAs are substantially less folded than messenger RNAs. Mol Biol Evol [Epub ahead of print]. [abstract]
Long noncoding RNAs (lncRNAs) have been widely regarded as crucial regulators in various biological processes involved in carcinogenesis. However, the comprehensive lncRNA expression signature in colorectal cancer remains fully unknown. Researchers at Nanjing Medical University performed a high throughput microarray assay to detect lncRNA expression profile in three paired human colorectal cancer tissues and their adjacent normal tissues. Additional 90 paired colorectal samples were collected to verify differently expression levels of two selected lncRNAs using q-RT-PCR assay. Bioinformatic approaches were performed to explore into the functions of these differently expressed lncRNAs.
Microarray assay showed a series of lncRNAs were differently expressed in colorectal cancer. Two of the lncRNAs, HOTAIR and a novel lncRNA, lncRNA-422 were confirmed in more samples (P=0.015 for HOTAIR and P=0.027 for lncRNA-422, respectively). GSEA indicated that gene sets most correlated with them were those named up-regulated in KRAS-over, down-regulated in JAK2-knockout, down-regulated in PDGF-over and down-regulated in TBK1-knockout, all of which were cancer-related. Subsequently, GO analyses of most significantly correlated coding genes of HOTAIR and lncRNA-422 showed that these two lncRNAs may participate in carcinogenesis by regulating protein coding genes involved in special biological process relevant to cancer.
This study demonstrated that different lncRNA expression patterns were involved in colorectal cancer. Besides, HOTAIR and lncRNA-422 were identified to participate in colorectal cancer. Further studies into biological mechanisms of differently expressed lncRNAs identified in this study will help to provide new perspective in colorectal cancer pathogenesis.
- Xue Y, Ma G, Gu D, Zhu L, Hua Q, Du M, Chu H, Tong N, Chen J, Zhang Z, Wang M. (2014) Genome-wide analysis of long noncoding RNA signature in human colorectal cancer. Gene [Epub ahead of print]. [abstract]
|Tuesday, October 14, 2014|
|University of Virginia School of Medicine, Charlottesville, EUA|
SEMINAR | 14 OCTOBER | 12:00 | MAIN AUDITORIUM
Small and long noncoding RNAs in control of cell proliferation and differentiation
Anindya Dutta, University of Virginia School of Medicine, Charlottesville, EUA