Long noncoding RNAs and Alzheimer's disease

LncRNA OIP5-AS1/cyrano suppresses GAK expression to control mitosis

Some long noncoding RNAs (lncRNAs) can regulate gene expression programs, in turn affecting specific cellular processes. We sought to identify the mechanism through which the lncRNA OIP5-AS1, which is abundant in the cytoplasm, suppressed cell proliferation. Silencing of OIP5-AS1 in human cervical carcinoma HeLa cells triggered the appearance of many aberrant (monopolar, multipolar, misaligned) mitotic spindles. Through a combination of approaches to pull down mRNAs bound to OIP5-AS1 and identify proteins differentially expressed when OIP5-AS1 was silenced, we identified a subset of human cell cycle regulatory proteins encoded by mRNAs that interacted with OIP5-AS1 in HeLa cells. Further analysis revealed that GAK mRNA, which encodes a cyclin G-associated kinase important for mitotic progression, associated prominently with OIP5-AS1. The interaction between these two transcripts led to a reduction in GAK mRNA stability and GAK protein abundance, as determined in cells in which OIP5-AS1 levels were increased or decreased. Importantly, the aberrant mitotic cell division seen after silencing OIP5-AS1 was partly rescued if GAK was simultaneously silenced. These findings indicate that the abnormal mitoses seen after silencing OIP5-AS1 were caused by an untimely rise in GAK levels and suggest that OIP5-AS1 suppresses cell proliferation at least in part by reducing GAK levels.

Plasma long non-coding RNA BACE1 as a novel biomarker for diagnosis of Alzheimer disease

Backgrounds

Long non-coding RNA (LncRNA) have been reported to be involved in the pathogenesis of neurodegenerative diseases, but whether it can serve as a biomarker for Alzheimer disease (AD) is not yet known.

Methods

The present study selected four specific LncRNA (17A, 51A, BACE1 and BC200) as possible AD biomarker. RT-qPCR was performed to validate the LncRNA. Receiver operating characteristic curve (ROC) and area under the ROC curve (AUC) were applied to study the potential of LncRNA as a biomarker in a population of 88 AD patients and 72 control individuals.

Results

We found that the plasma LncRNA BACE1 level of AD patients was significantly higher than that of healthy controls (p = 0.006). Plasma level of LncRNA 17A, 51A and BC200 did not show a significant difference between two groups (p = 0.098, p = 0.204 and p = 0.232, respectively). ROC curve analysis showed that LncRNA BACE1 was the best candidate of these LncRNA (95% CI: 0.553–0.781, p = 0.003). In addition, no correlation was found for expression of these LncRNA in both control and AD groups with age or MMSE scale (p > 0.05).

Conclusions

Our present study compared the plasma level of four LncRNA between AD and non-AD patients, and found that the level of the BACE1 is increased in the plasma of AD patients and have a high specificity (88%) for AD, indicating BACE1 may be a potential candidate biomarker to predict AD.

Electronic supplementary material

The online version of this article (10.1186/s12883-017-1008-x) contains supplementary material, which is available to authorized users.

Long Noncoding RNA EBF3-AS Promotes Neuron Apoptosis in Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia; its pathophysiological mechanism remains unclear. Long noncoding RNAs (lncRNAs) play key roles in AD. lncRNA EBF3-AS has been found dysregulated in AD, which is abundantly expressed in the brain. The aim of this study was to investigate the role of EBF3-AS in AD. Results showed that the expressions of lncRNA EBF3-AS and EBF3 (early B cell factor 3) were upregulated in hippocampus of APP/PS1 mice (AD model mice). EBF3-AS knockdown by siRNA inhibited the apoptosis induced by Aβ_25-35 and okadaic acid (OA) in SH-SY5Y. The expression of EBF3 was downregulated in Aβ_25-35- and OA-treated SH-SY5Y, which was reversed by EBF3-AS knockdown. EBF3 knockdown can reverse the Aβ_25-35-induced apoptosis in SH-SY5Y. These results revealed that lncRNA EBF3-AS promoted neuron apoptosis in AD, and involved in regulating EBF3 expression. EBF3-AS may be a new therapeutic target for treatment of AD.

Regulation of Human Breast Cancer by the Long Non-Coding RNA H19

Breast cancer is one of the most common causes of cancer related deaths in women. Despite the progress in early detection and use of new therapeutic targets associated with development of novel therapeutic options, breast cancer remains a major problem in public health. Indeed, even if the survival rate has improved for breast cancer patients, the number of recurrences within five years and the five-year relative survival rate in patients with metastasis remain dramatic. Thus, the discovery of new molecular actors involved in breast progression is essential to improve the management of this disease. Numerous data indicate that long non-coding RNA are implicated in breast cancer development. The oncofetal lncRNA H19 was the first RNA identified as a riboregulator. Studying of this lncRNA revealed its implication in both normal development and diseases. In this review, we summarize the different mechanisms of action of H19 in human breast cancer.

Gene regulation of mammalian long non-coding RNA

RNA polymerase II (Pol II) transcribes two classes of RNAs, protein-coding and non-protein-coding (ncRNA) genes. ncRNAs are also synthesized by RNA polymerases I and III (Pol I and III). In humans, the number of ncRNA genes exceeds more than twice that of protein-coding genes. However, the history of studying Pol II-synthesized ncRNA is relatively short. Since early 2000s, important biological and pathological functions of these ncRNA genes have begun to be discovered and intensively studied. And transcription mechanisms of long non-coding RNA (lncRNA) have been recently reported. Transcription of lncRNAs utilizes some transcription factors and mechanisms shared in that of protein-coding genes. In addition, tissue specificity in lncRNA gene expression has been shown. LncRNAs play essential roles in regulating the expression of neighboring or distal genes through different mechanisms. This leads to the implication of lncRNAs in a wide variety of biological pathways and pathological development. In this review, the newly discovered transcription mechanisms, characteristics, and functions of lncRNA are discussed.

Long Noncoding RNAs and RNA-Binding Proteins in Oxidative Stress, Cellular Senescence, and Age-Related Diseases

Cellular senescence is a complex biological process that leads to irreversible cell-cycle arrest. Various extrinsic and intrinsic insults are associated with the onset of cellular senescence and frequently accompany genomic or epigenomic alterations. Cellular senescence is believed to contribute to tumor suppression, immune response, and tissue repair as well as aging and age-related diseases. Long noncoding RNAs (lncRNAs) are >200 nucleotides long, poorly conserved, and transcribed in a manner similar to that of mRNAs. They are tightly regulated during various cellular and physiological processes. Although many lncRNAs and their functional roles are still undescribed, the importance of lncRNAs in a variety of biological processes is widely recognized. RNA-binding proteins (RBPs) have a pivotal role in posttranscriptional regulation as well as in mRNA transport, storage, turnover, and translation. RBPs interact with mRNAs, other RBPs, and noncoding RNAs (ncRNAs) including lncRNAs, and they are involved in the regulation of a broad spectrum of cellular processes. Like other cell fate regulators, lncRNAs and RBPs, separately or cooperatively, are implicated in initiation and maintenance of cellular senescence, aging, and age-related diseases. Here, we review the current understanding of both lncRNAs and RBPs and their association with oxidative stress, senescence, and age-related diseases.

Prognostic value of the long noncoding RNA HOTTIP in human cancers

Human Homeobox A transcript at the distal tip (HOTTIP) is a putative oncogene in solid tumors. We performed a meta-analysis to investigate the association between HOTTIP expression and clinical outcomes in cancer patients. Eligible studies were collected from a literature search of the online electronic databases of Embase, Web of Science, PubMed and the China National Knowledge Infrastructure (up to January 2, 2017). Fixed-effects models were used to compute pooled odds ratios (ORs) and hazard ratios (HRs). In total, we analyzed nine studies that included 800 patients with seven tumor types. Overall survival was lower for patients with high HOTTIP expression than for those with low expression (HR = 2.30, 95% confidence interval [CI]: 1.81–2.91, P < 0.001). High HOTTIP expression was also associated with lymph node metastasis (OR = 2.40, 95% CI: 1.70–3.37, P < 0.001), distant metastasis (OR = 3.30, 95% CI: 1.78–6.12, P < 0.001), poor tumor differentiation (OR = 1.55, 95% CI: 1.03–2.32, P = 0.036) and a poor clinical stage (OR = 3.28, 95% CI: 2.22–4.83, P < 0.001). This meta-analysis demonstrated that high HOTTIP expression in cancer patients is associated with poor clinical outcomes. Thus, HOTTIP is a potential predictive biomarker of cancer.

SASP regulation by noncoding RNA

Noncoding RNAs (ncRNAs), including micro (mi)RNAs, long noncoding (lnc)RNAs, and circular (circ)RNAs, control specific gene expression programs by regulating transcriptional, post-transcriptional, and post-translational processes. Through their broad influence on protein expression and function, ncRNAs have been implicated in virtually all cellular processes such as proliferation, senescence, quiescence, differentiation, apoptosis, and the stress and immune responses. Senescence is a cellular phenotype associated with the physiologic decline of aging and with age-related pathologies. Besides their characteristic terminal growth arrest and differential gene expression programs, senescent cells are known to secrete potent pro-inflammatory, angiogenic, and tissue-remodeling factors. This important trait, known as the senescence-associated secretory phenotype (SASP), influences many biological processes such as tissue repair and regeneration, tumorigenesis, and the aging-associated pro-inflammatory state. Here, we review the microRNAs, lncRNAs, and circRNAs that influence the production of SASP factors and discuss the rising interest in SASP-regulatory ncRNAs as diagnostic and therapeutic targets.