Regulatory long non-coding RNA and its functions

Long non-coding RNAs; potential contributors in cancer chemoresistance through modulating diverse molecular mechanisms and signaling pathways

One of the mainstays of cancer treatment is chemotherapy. Drug resistance, however, continues to be the primary factor behind clinical treatment failure. Gene expression is regulated by long non-coding RNAs (lncRNAs) in several ways, including chromatin remodeling, translation, epigenetic, and transcriptional levels. Cancer hallmarks such as DNA damage, metastasis, immunological evasion, cell stemness, drug resistance, metabolic reprogramming, and angiogenesis are all influenced by LncRNAs. Numerous studies have been conducted on LncRNA-driven mechanisms of resistance to different antineoplastic drugs. Diverse medication kinds elicit diverse resistance mechanisms, and each mechanism may have multiple contributing factors. As a result, several lncRNAs have been identified as new biomarkers and therapeutic targets for identifying and managing cancers. This compels us to thoroughly outline the crucial roles that lncRNAs play in drug resistance. In this regard, this article provides an in-depth analysis of the recently discovered functions of lncRNAs in the pathogenesis and chemoresistance of cancer. As a result, the current research might offer a substantial foundation for future drug resistance-conquering strategies that target lncRNAs in cancer therapies.

Integrative taxonomic analyses reveal that rapid genetic divergence drives Acropora speciation

Reef-building corals provide the structural basis for one of Earth's most spectacular and diverse but increasingly threatened ecosystems. The reef-building coral genus Acropora may have undergone substantial speciation during the Pleistocene climate and sea-level changes. Here, we aimed to evaluate the speciation history of four morphologically similar tabular Acropora species (Acropora aff. hyacinthus, A. cf. bifurcata, A. cf. cytherea, and A. cf. subulata) using an integrative approach with morphology, genetic, and reproduction methodology. Extensive morphological analyses showed that these four species are distinct and exhibited high gamete incompatibility, preventing hybridization. Furthermore, population structure and principal component analyses with SNPs (>60,000) indicated that these species were genetically distinct, and the ABBA-BABA test did not support introgression among these species. Many of their coding and noncoding RNA sequences showed high genetic variance at loci with high Fst values along the genome. Comparison of these orthologs with those of other Acropora species suggested that many of these genes are under positive selection, which could be associated with spawning time, gamete, and morphological divergence. Our findings show that the speciation of tabular Acropora occurred without hybridization, and the divergence accompanying the rapid evolution of genes in species-rich Acropora could be associated with speciation.

A review on expression and regulatory mechanisms of miR-337-3p in cancer

A group of diseases generally referred to as cancer represents a serious threat to people's health all over the world and has a significant negative influence on every aspect of the lives of patients. The development of cancer is influenced by several environmental, genetic, and epigenetic factors. MicroRNAs (miRNAs), a class of non-coding RNAs, can alter the expression of genes involved in cell proliferation, migration, metastasis, and apoptosis, lead to the pathogenesis of cancer. Additionally, several effectors modify miRNAs directly, including methylation, circular RNAs, and long non-coding RNAs (lncRNAs). In this review, we have explained the role of mir-337-3p in the pathways related to the pathogenesis of different cancers. Studying the functional role of miR-337-3p is necessary for detecting novel molecules as tumor markers and discovering novel targets for cancer treatment.

Noncoding RNAs: Versatile regulators of endothelial dysfunction

Noncoding RNAs have recently emerged as versatile regulators of endothelial dysfunction in atherosclerosis, a chronic inflammatory disease characterized by the formation of plaques within the arterial walls. Through their ability to modulate gene expression, noncoding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, play crucial roles in various cellular processes involved in endothelial dysfunction (ECD), such as inflammation, pyroptosis, migration, proliferation, apoptosis, oxidative stress, and angiogenesis. This review provides an overview of the current understanding of the regulatory roles of noncoding RNAs in endothelial dysfunction during atherosclerosis. It highlights the specific noncoding RNAs that have been implicated in the pathogenesis of ECD, their target genes, and the mechanisms by which they contribute to ECD. Furthermore, we have reviewed the current therapeutics in atherosclerosis and explore their interaction with noncoding RNAs. Understanding the intricate regulatory network of noncoding RNAs in ECD may open up new opportunities for the development of novel therapeutic strategies to combat ECD.

MALAT1 expression is associated with aggressive behavior in indolent B-cell neoplasms

MALAT1 long non-coding RNA has oncogenic roles but has been poorly studied in indolent B-cell neoplasms. Here, MALAT1 expression was analyzed using RNA-seq, microarrays or qRT-PCR in primary samples from clinico-biological subtypes of chronic lymphocytic leukemia (CLL, n = 266), paired Richter transformation (RT, n = 6) and follicular lymphoma (FL, n = 61). In peripheral blood (PB) CLL samples, high MALAT1 expression was associated with a significantly shorter time to treatment independently from other known prognostic factors. Coding genes expressed in association with MALAT1 in CLL were predominantly related to oncogenic pathways stimulated in the lymph node (LN) microenvironment. In RT paired samples, MALAT1 levels were lower, concordant with their acquired increased independency of external signals. Moreover, MALAT1 levels in paired PB/LN CLLs were similar, suggesting that the prognostic value of MALAT1 expression in PB is mirroring expression differences already present in LN. Similarly, high MALAT1 expression in FL predicted for a shorter progression-free survival, in association with expression pathways promoting FL pathogenesis. In summary, MALAT1 expression is related to pathophysiology and more aggressive clinical behavior of indolent B-cell neoplasms. Particularly in CLL, its levels could be a surrogate marker of the microenvironment stimulation and may contribute to refine the clinical management of these patients.

LncRNA-84277 is involved in chronic pain-related depressive behaviors through miR-128-3p/SIRT1 axis in central amygdala

Long-term chronic pain can lead to depression. However, the mechanism underlying chronic pain-related depression remains unclear. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase (HDAC). Our previous studies have demonstrated that SIRT1 in the central nucleus of the amygdala (CeA) is involved in the development of chronic pain-related depression. In addition, increasing studies have indicated that long non-coding RNAs (lncRNAs) play a vital role in the pathogenesis of pain or depression. However, whether lncRNAs are involved in SIRT1-mediated chronic pain-related depression remains largely unknown. In this study, we identified that a novel lncRNA-84277 in CeA was the upstream molecule to regulate SIRT1 expression. Functionally, lncRNA-84277 overexpression in CeA significantly alleviated the depression-like behaviors in spared nerve injury (SNI)-induced chronic pain rats, whereas lncRNA-84277 knockdown in CeA induced the depression-like behaviors in naïve rats. Mechanically, lncRNA-84277 acted as a competing endogenous RNA (ceRNA) to upregulate SIRT1 expression by competitively sponging miR-128-3p, and therefore improved chronic pain-related depression-like behaviors. Our findings reveal the critical role of lncRNA-84277 in CeA specifically in guarding against chronic pain-related depression via a ceRNA mechanism and provide a potential therapeutic target for chronic pain-related depression.

Circ_0047921 acts as the sponge of miR-1287-5p to stimulate lung cancer progression by regulating proliferation, migration, invasion, and glycolysis of lung cancer cells

Background

Lung cancer is a common respiratory system disease caused by multiple factors. Circular RNAs (circRNAs) play vital roles in tumorigenesis, including lung cancer. This study aimed to clarify the role and underlying molecular mechanisms of circ_0047921 in lung cancer.

Methods

Real-time quantitative polymerase chain reaction (RT-qPCR) was used to assess the expression levels of circ_0047921, La-related protein 1 (LARP1), and miR-1287-5p. Cell proliferation was analyzed by CCK-8 and EdU assays. Transwell assay was used to assess migration and invasion. Western blot assay was employed to quantify protein expression. Glycolysis ability of cell was determined by measuring glucose consumption and lactate production with matched kits. The relationship between miR-1287-5p and circ_0047921 or LARP1 was confirmed by dual-luciferase reporter assay. In addition, a xenograft model was established to clarify the functional role of circ_0047921 in vivo.

Results

Circ_0047921 was highly expressed in lung cancer tissues and cells. Circ_0047921 downregulation repressed proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) and glycolysis in lung cancer cells. Circ_0047921 targeted miR-1287-5p to deplete miR-1287-5p expression. The effects caused by circ_0047921 downregulation were reversed by miR-1287-5p inhibition. In addition, LARP1 was a target of miR-1287-5p, and circ_0047921 could directly interact with miR-1287-5p to increase the expression of LARP1. The effects caused by circ_0047921 downregulation were also reversed by LARP1 overexpression. Circ_0047921 silencing impeded the growth of tumor in vivo.

Conclusion

Circ_0047921 was overexpressed in lung cancer, and circ_0047921 targeted miR-1287-5p to modulate LARP1 expression, thereby facilitating the development of lung cancer.

Trial registration

The present study was approved by the ethical review committee of The First People’s Hospital of Chenzhou, Southern Medical University with reference no. 20210106.

1. Circ_0047921 was upregulated in lung cancer tissues and cells.

2. Circ_0047921/miR-1287-5p/LARP1 axis played a key role in proliferation, migration, invasion, EMT and glycolysis of lung cancer cells.

3. Circ_0047921 regulated LARP1 by sponging miR-1287-5p in lung cancer.

Role of lncRNA FAM83H antisense RNA1 (FAM83H-AS1) in the progression of non-small cell lung cancer by regulating the miR-545-3p/heparan sulfate 6-O-sulfotransferase (HS6ST2) axis

Long non-coding RNAs (lncRNAs) are crucial regulators of cancer pathogenesis and are potentially useful diagnostic and prognostic biomarker tools. FAM83H antisense RNA1 (FAM83H-AS1) has been reported to be a vital regulator of different cancers; however, little attention has been paid to its significance in lung cancer. Non-tumorigenic lung cell line BEAS-2B and adenocarcinoma lung cancer cell lines NCI-H1299 and HCC827 were used in the present study. In addition, RNA immunoprecipitation, Western blotting, quantitative reverse transcription-PCR (qRT-PCR), and luciferase reporter assays were used to dissect the role of FAM83H-AS1 in lung cancer progression. The results revealed that FAM83H-AS1 is highly expressed in lung cancer tissues, and its knockdown inhibits lung cancer cell invasion and proliferation reducing tumor growth in vivo. Besides, we found that FAM83H-AS1 targets miR-545-3p, and a negative correlation exists between their expression in lung cancer tissues. Simultaneously, miR-545-3p negatively regulates heparan sulfate 6-O-sulfotransferase (HS6ST2). Moreover, inhibition of miR-545-3p promoted HS6ST2 protein expression and lung cancer cell invasion. FAM83H-AS1 favors non-small cell lung cancer by targeting the miR-545-3p/HS6ST2 axis, supporting the possibility of developing FAM83H-AS1 as a target for NSCLC intervention.

EGFR-AS1 Promotes Nonsmall Cell Lung Cancer (NSCLC) Progression via Downregulating the miR-524-5p/DRAM1 Axis and Inhibiting Autophagic Lysosomal Degradation

Nonsmall cell lung cancer (NSCLC) accounts for the majority of lung cancers. Studies have revealed the regulatory role of lncRNAs in cancer pathogenesis and their potential use as diagnostic and prognostic biomarkers. The epidermal growth factor receptor antisense RNA 1 (EGFR-AS1) has been reported to be upregulated in NSCLC tissues, while its detailed mechanism in lung cancer needs to be explored. DNA damage-regulated autophagy modulator 1 (DRAM1) has been known to act as a tumor suppressor in NSCLC, and miR-524-5p has been reported to be a biomarker in idiopathic pulmonary fibrosis and different lung disorders. Our investigation revealed that EGFR-AS1 is highly expressed in lung cancer tissues, and its knockdown inhibited lung cancer cell invasion and viability and reduced tumor growth in vivo. We also found that EGFR-AS1 targets miR-524-5p, and there was a negative correlation between their expressions in lung cancer tissues. Simultaneously, miR-524-5p has been found to promote DRAM1 expression. In addition, the inhibition of miR-524-5p diminished DRAM1 protein expression and promoted lung cancer cell invasion. Our study has revealed that EGFR-AS1 contributes to the pathogenesis of NSCLC by inhibiting autophagic-lysosomal degradation via targeting the miR-524-5p/DRAM1 axis. This finding elucidated for the first time the role of EGFR-AS1 in lung cancer progression and the positive regulatory function of miR-524-5p in regulating DRAM1 protein and suppressing lung cancer progression. This novel mechanism provided a better insight into the pathogenesis of lung cancer and presented a better strategy for the treatment of lung cancer.

Hundreds of LncRNAs Display Circadian Rhythmicity in Zebrafish Larvae

Long noncoding RNAs (lncRNAs) have been shown to play crucial roles in various life processes, including circadian rhythms. Although next generation sequencing technologies have facilitated faster profiling of lncRNAs, the resulting datasets require sophisticated computational analyses. In particular, the regulatory roles of lncRNAs in circadian clocks are far from being completely understood. In this study, we conducted RNA-seq-based transcriptome analysis of zebrafish larvae under both constant darkness (DD) and constant light (LL) conditions in a circadian manner, employing state-of-the-art computational approaches to identify approximately 3220 lncRNAs from zebrafish larvae, and then uncovered 269 and 309 lncRNAs displaying circadian rhythmicity under DD and LL conditions, respectively, with 30 of them are coexpressed under both DD and LL conditions. Subsequently, GO, COG, and KEGG pathway enrichment analyses of all these circadianly expressed lncRNAs suggested their potential involvement in numerous biological processes. Comparison of these circadianly expressed zebrafish larval lncRNAs, with rhythmically expressed lncRNAs in the zebrafish pineal gland and zebrafish testis, revealed that nine (DD) and twelve (LL) larval lncRNAs are coexpressed in the zebrafish pineal gland and testis, respectively. Intriguingly, among peptides encoded by these coexpressing circadianly expressed lncRNAs, three peptides (DD) and one peptide (LL) were found to have the known domains from the Protein Data Bank. Further, the conservation analysis of these circadianly expressed zebrafish larval lncRNAs with human and mouse genomes uncovered one lncRNA and four lncRNAs shared by all three species under DD and LL conditions, respectively. We also investigated the conserved lncRNA-encoded peptides and found one peptide under DD condition conserved in these three species and computationally predicted its 3D structure and functions. Our study reveals that hundreds of lncRNAs from zebrafish larvae exhibit circadian rhythmicity and should help set the stage for their further functional studies.

Long noncoding RNA SNHG12 is a potential diagnostic and prognostic biomarker in various tumors

BACKGROUND

Tumors are the second most common cause of death in humans worldwide, second only to cardiovascular and cerebrovascular diseases. Although methods and techniques for the treatment of tumors continue to improve, the effect is not satisfactory. These may lack effective therapeutic targets. This study aimed to evaluate the value of SNHG12 as a biomarker in the prognosis and clinical characteristics of various cancer patients.

METHODS

We analyzed SNHG12 expression and plotted the survival curves of all cancer samples in the TCGA database using the GEPIA tool. Then, we searched for eligible papers up to April 1, 2019, in databases. Next, the data were extracted from studies examining SNHG12 expression, overall survival and clinicopathological features in patients with malignant tumors. We used Review Manager 5.3 and Stata 15 software to analyze the statistical data.

RESULTS

In the TCGA database, abnormally high expression of SNHG12 in tumor samples indicates that the patient has a poor prognosis. Results of meta-analysis is that SNHG12 high expression is related to low overall survival (HR = 2.72, 95% CI = 1.95-3.8, P < 0.00001), high tumor stage (OR = 3.94, 95% CI = 2.80-5.53, P < 0.00001), high grade (OR = 2.04, 95% CI = 1.18-3.51, P = 0.01), distant metastasis (OR = 2.20, 95% CI = 1.40-3.46, P = 0.0006), tumor size (OR = 2.79, 95% CI = 1.89-4.14, P < 0.00001), and lymph node metastasis (OR = 2.66, 95% CI = 1.65-4.29, P < 0.0001).

CONCLUSIONS

Our study confirmed that the high expression level of SNHG12 is closely related to the clinicopathological characteristics and prognosis of patients and is a new predictive biomarker for various cancer patients.

Identification of Rhythmically Expressed LncRNAs in the Zebrafish Pineal Gland and Testis

Noncoding RNAs have been known to contribute to a variety of fundamental life processes, such as development, metabolism, and circadian rhythms. However, much remains unrevealed in the huge noncoding RNA datasets, which require further bioinformatic analysis and experimental investigation-and in particular, the coding potential of lncRNAs and the functions of lncRNA-encoded peptides have not been comprehensively studied to date. Through integrating the time-course experimentation with state-of-the-art computational techniques, we studied tens of thousands of zebrafish lncRNAs from our own experiments and from a published study including time-series transcriptome analyses of the testis and the pineal gland. Rhythmicity analysis of these data revealed approximately 700 rhythmically expressed lncRNAs from the pineal gland and the testis, and their GO, COG, and KEGG pathway functions were analyzed. Comparative and conservative analyses determined 14 rhythmically expressed lncRNAs shared between both the pineal gland and the testis, and 15 pineal gland lncRNAs as well as 3 testis lncRNAs conserved among zebrafish, mice, and humans. Further, we computationally analyzed the conserved lncRNA-encoded peptides, and revealed three pineal gland and one testis lncRNA-encoded peptides conserved among these three species, which were further investigated for their three-dimensional (3D) structures and potential functions. Our computational findings provided novel annotations and regulatory mechanisms for hundreds of rhythmically expressed pineal gland and testis lncRNAs in zebrafish, and set the stage for their experimental studies in the near future.

Non-Coding RNAs: Novel Players in Insulin Resistance and Related Diseases

The rising prevalence of metabolic diseases related to insulin resistance (IR) have stressed the urgent need of accurate and applicable tools for early diagnosis and treatment. In the last decade, non-coding RNAs (ncRNAs) have gained growing interest because of their potential role in IR modulation. NcRNAs are variable-length transcripts which are not translated into proteins but are involved in gene expression regulation. Thanks to their stability and easy detection in biological fluids, ncRNAs have been investigated as promising diagnostic and therapeutic markers in metabolic diseases, such as type 2 diabetes mellitus (T2D), obesity and non-alcoholic fatty liver disease (NAFLD). Here we review the emerging role of ncRNAs in the development of IR and related diseases such as obesity, T2D and NAFLD, and summarize current evidence concerning their potential clinical application.

LDAH2V: Exploring Meta-Paths Across Multiple Networks for lncRNA-Disease Association Prediction

Accumulating evidence has demonstrated dysfunctions of long non-coding RNAs (lncRNAs) are involved in various complex human diseases. However, even today, the relationships between lncRNAs and diseases remain unknown in most cases. Developing effective computational approaches to identify potential lncRNA-disease associations has become a hot topic. Existing network-based approaches are usually focused on the intrinsic features of lncRNAs and diseases but ignore the heterogeneous information of biological networks. Considering the limitations in previous methods, we propose LDAH2V, an efficient computational framework for predicting potential lncRNA-disease associations. LDAH2V uses the HIN2Vec to calculate the meta-path and feature vector for each lncRNA-disease pair in the heterogeneous information network (HIN), which consists of lncRNA similarity network, disease similarity network, miRNA similarity network, and the associations between them. Then, a Gradient Boosting Tree (GBT) classifier to predict lncRNA-disease associations is built with the feature vectors. The results show that LDAH2V performs significantly better than the four existing state-of-the-art methods and gains an AUC of 0.97 in the 10-fold cross-validation test. Furthermore, case studies of colon cancer and ovarian cancer-related lncRNAs have been confirmed in related databases and medical literature.

The Role of Sex-specific Long Non-coding RNAs in Cancer Prevention and Therapy

The functions of a large number of non-coding genes in human DNA have yet to be accurately identified. Long non-coding RNA (lncRNA) measuring 10 kb or less in length regulates transcription or post-transcriptional events. The lncRNAs have attracted increased attention of researchers in recent years. In this review, we summarize the recently published lncRNAs which are known to influence cancer development and progression. We also discuss recent studies investigating tumor-specific lncRNA expression. These lncRNAs provide very useful information that allows prediction of the degree of malignancy and a survival rate in cancer patients as clinically relevant biomarkers. Because symptoms and progression of cancer differ from onset to death between males and females, it is important to consider the gender of the patient when diagnosing cancer and predicting the progression. Considering the importance of gender difference, we also examine the influence of sex hormones involved in the expression and regulation of lncRNAs as biomarkers. Many of the lncRNAs examined in this review have been studied in cancers occurring in the female or male reproductive organs, but the association between lncRNAs and sex hormones has also been reported in common organs such as the lung, renal and colon. Although lncRNAs have not yet been widely used as definitive cancer indicators, recent studies have demonstrated the potential role of lncRNAs as biomarkers and therapeutic targets reflecting sex-specificity in a number of different cancers.

Targeting Epigenetics in Lung Cancer

The epigenetic landscape, which in part includes DNA methylation, chromatin organization, histone modifications, and noncoding RNA regulation, greatly contributes to the heterogeneity that makes developing effective therapies for lung cancer challenging. This review will provide an overview of the epigenetic alterations that have been implicated in all aspects of cancer pathogenesis and progression as well as summarize clinical applications for targeting epigenetics in the treatment of lung cancer.

LINC00467 Promotes Prostate Cancer Progression via M2 Macrophage Polarization and the miR-494-3p/STAT3 Axis

Background

The long non-coding RNA LINC00467 plays a vital role in many malignancies. Nevertheless, the role of LINC00467 in prostate carcinoma (PC) is unknown. Herein, we aimed to explore the mechanism by which LINC00467 regulates PC progression.

Methods

We used bioinformatics analyses and RT-qPCR to investigate the expression of LINC00467 in PC tissues and cells. The function of LINC00467 in the progression of PC was confirmed by loss-of-function experiments. PC cell proliferation was assessed by CCK-8 and EdU assays. The cell cycle progression of PC cells was examined by flow cytometry. Moreover, Transwell assays were used to investigate the migration and invasion of PC cells. Western blot assays were used to detect the expression of factors associated with epithelial–mesenchymal transition. The interactions of LINC00467 with prostate cancer progression and M2 macrophage polarization were confirmed by RT-qPCR. The subcellular localization of LINC00467 was investigated via the fractionation of nuclear and cytoplasmic RNA. Bioinformatics data analysis was used to predict the correlation of LINC00467 expression with miR-494-3p expression. LINC00467/miR-494-3p/STAT3 interactions were identified by using a dual-luciferase reporter system. Finally, the influence of LINC00467 expression on PC progression was investigated with an in vivo nude mouse model of tumorigenesis.

Results

We established that LINC00467 expression was upregulated in PC tissues and cells. Downregulated LINC00467 expression inhibited PC cell growth, cell cycle progression, migration, and invasion. Downregulated LINC00467 expression similarly inhibited PC cell migration via M2 macrophage polarization. Western blot analysis showed that LINC00467 could regulate the STAT3 pathway. We established that LINC00467 is mainly localized to the cytoplasm. Bioinformatics analysis and rescue experiments indicated that LINC00467 promotes PC progression via the miR-494-3p/STAT3 axis. Downregulated LINC00467 expression was also able to suppress PC tumor growth in vivo.

Conclusions

Our study reveals that LINC00467 promotes prostate cancer progression via M2 macrophage polarization and the miR-494-3p/STAT3 axis.

Computational Analysis Predicts Hundreds of Coding lncRNAs in Zebrafish

Simple Summary

Noncoding RNAs (ncRNAs) regulate a variety of fundamental life processes such as development, physiology, metabolism and circadian rhythmicity. RNA-sequencing (RNA-seq) technology has facilitated the sequencing of the whole transcriptome, thereby capturing and quantifying the dynamism of transcriptome-wide RNA expression profiles. However, much remains unrevealed in the huge noncoding RNA datasets that require further bioinformatic analysis. In this study, we applied six bioinformatic tools to investigate coding potentials of approximately 21,000 lncRNAs. A total of 313 lncRNAs are predicted to be coded by all the six tools. Our findings provide insights into the regulatory roles of lncRNAs and set the stage for the functional investigation of these lncRNAs and their encoded micropeptides.

Abstract

Recent studies have demonstrated that numerous long noncoding RNAs (ncRNAs having more than 200 nucleotide base pairs (lncRNAs)) actually encode functional micropeptides, which likely represents the next regulatory biology frontier. Thus, identification of coding lncRNAs from ever-increasing lncRNA databases would be a bioinformatic challenge. Here we employed the Coding Potential Alignment Tool (CPAT), Coding Potential Calculator 2 (CPC2), LGC web server, Coding-Non-Coding Identifying Tool (CNIT), RNAsamba, and MicroPeptide identification tool (MiPepid) to analyze approximately 21,000 zebrafish lncRNAs and computationally to identify 2730–6676 zebrafish lncRNAs with high coding potentials, including 313 coding lncRNAs predicted by all the six bioinformatic tools. We also compared the sensitivity and specificity of these six bioinformatic tools for identifying lncRNAs with coding potentials and summarized their strengths and weaknesses. These predicted zebrafish coding lncRNAs set the stage for further experimental studies.

Integrative Analysis of lncRNA-mRNA Coexpression in Human Lung Epithelial Cells Exposed to Dimethyl Selenide-Derived Secondary Organic Aerosols

Dimethyl selenide (DMSe) is one of the major volatile organoselenium compounds released into the atmosphere through plant metabolism and microbial methylation. DMSe has been recently revealed as a precursor of secondary organic aerosol (SOA), and its resultant SOA possesses strong oxidizing capability toward thiol groups that can perturb several major biological pathways in human airway epithelial cells and is linked to genotoxicity, DNA damage, and p53-mediated stress responses. Mounting evidence has suggested that long noncoding RNAs (lncRNAs) are involved in stress responses to internal and environmental stimuli. However, the underlying molecular interactions remain to be elucidated. In this study, we performed integrative analyses of lncRNA-mRNA coexpression in the transformed human bronchial epithelial BEAS-2B cell line exposed to DMSe-derived SOA. We identified a total of 971 differentially expressed lncRNAs in BEAS-2B cells exposed to SOA derived from O₃ and OH oxidation of DMSe. Gene ontology (GO) network analysis of cis-targeted genes showed significant enrichment of DNA damage, apoptosis, and p53-mediated stress response pathways. trans-Acting lncRNAs, including PINCR, PICART1, DLGAP1-AS2, and LINC01629, known to be associated with human carcinogenesis, also showed altered expression in cell treated with DMSe-SOA. Overall, this study highlights the regulatory role of lncRNAs in altered gene expression induced by DMSe-SOA exposure.

Identification of Proteins of Tobacco Mosaic Virus by Using a Method of Feature Extraction

Tobacco mosaic virus, TMV for short, is widely distributed in the global tobacco industry and has a significant impact on tobacco production. It can reduce the amount of tobacco grown by 50-70%. In this research of study, we aimed to identify tobacco mosaic virus proteins and healthy tobacco leaf proteins by using machine learning approaches. The experiment's results showed that the support vector machine algorithm achieved high accuracy in different feature extraction methods. And 188-dimensions feature extraction method improved the classification accuracy. In that the support vector machine algorithm and 188-dimensions feature extraction method were finally selected as the final experimental methods. In the 10-fold cross-validation processes, the SVM combined with 188-dimensions achieved 93.5% accuracy on the training set and 92.7% accuracy on the independent validation set. Besides, the evaluation index of the results of experiments indicate that the method developed by us is valid and robust.

Novel Approaches to Profile Functional Long Noncoding RNAs Associated with Stem Cell Pluripotency

The pluripotent state of stem cells depends on the complicated network orchestrated by thousands of factors and genes. Long noncoding RNAs (lncRNAs) are a class of RNA longer than 200 nt without a protein-coding function. Single-cell sequencing studies have identified hundreds of lncRNAs with dynamic changes in somatic cell reprogramming. Accumulating evidence suggests that they participate in the initiation of reprogramming, maintenance of pluripotency, and developmental processes by cis and/or trans mechanisms. In particular, they may interact with proteins, RNAs, and chromatin modifier complexes to form an intricate pluripotency-associated network. In this review, we focus on recent progress in approaches to profiling functional lncRNAs in somatic cell reprogramming and cell differentiation.

Identification of a Multi-Long Noncoding RNA Signature for the Diagnosis of Type 1 Diabetes Mellitus

Due to the increasing prevalence of type 1 diabetes mellitus (T1DM) and its complications, there is an urgent need to identify novel methods for predicting the occurrence and understanding the pathogenetic mechanisms of the disease. Accumulated data have demonstrated the potential of long noncoding RNAs (lncRNAs), as biomarkers in establishing diagnosis and predicting prognosis of numerous diseases. Yet, little is known about the expression patterns and regulatory roles of lncRNAs in the pathogenesis of T1DM and whether they can be used as diagnostic biomarkers for the disease. To further explore these questions, in the present study, we conducted a comparative analysis of the expression patterns of lncRNAs between 20 T1DM patients and 42 health controls by retrospectively analyzing a published microarray data set. Our results indicate that, compared with healthy controls, diabetic patients had altered levels of lncRNAs. Then, we used three time cross-validation strategy and support vector machine to propose a specific 26-lncRNA signature (termed 26LncSigT1DM). This 26LncSigT1DM signature can be used to effectively distinguish between healthy and diabetic individuals (area under the curve = 0.825) of a validation cohort. After the 26LncSigT1DM was prospectively validated, we used Pearson correlation to identify 915 mRNAs, whose expression levels were positively correlated with those of the 26 lncRNAs. According to their Gene Ontology annotations, these mRNAs participate in processes including cellular response to stimulus, cell communication, multicellular organismal process, and cell motility. Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the genes encoding the 915 mRNAs may be associated with the NOD-like receptor signaling pathway, transforming growth factor β signaling pathway, and mineral absorption, suggesting that the deregulation of these lncRNAs may mediate inflammatory abnormalities and immune dysfunctions, which jointly promote the pathogenesis of T1DM. Thus, our study identifies a novel diagnostic tool and may shed more light on the molecular mechanisms underlying the pathogenesis of T1DM.

Genome‑wide integrated analysis demonstrates widespread functions of lncRNAs in mammary gland development and lactation in dairy goats

Background

The mammary gland is a unique organ for milk synthesis, secretion and storage, and it undergoes cyclical processes of development, differentiation, lactation and degeneration. At different developmental periods, the biological processes governing mammary gland physiology and internal environmental homeostasis depend on a complex network of genes and regulatory factors. Emerging evidence indicates that lncRNAs have arbitrarily critical functions in regulating gene expression in many organisms; however, the systematic characteristics, expression, and regulatory roles of lncRNAs in the mammary gland tissues of dairy goats have not been determined.

Result

In the present study, we profiled long noncoding RNA (lncRNA) expression in the mammary gland tissues of Laoshan dairy goats (Capra hircus) from different lactation periods at the whole-genome level, to identify, characterize and explore the regulatory functions of lncRNAs. A total of 37,249 transcripts were obtained, of which 2381 lncRNAs and 37,249 mRNAs were identified, 22,488 transcripts, including 800 noncoding transcripts and 21,688 coding transcripts, differed significantly (p ≤ 0.01) among the different lactation stages. The results of lncRNA-RNA interaction analysis showed that six known lncRNAs belonging to four families were identified as the precursors of 67 known microRNAs; 1478 and 573 mRNAs were predicted as hypothetical cis-regulation elements and antisense mRNAs, respectively. GO annotation and KEGG analysis indicated that the coexpressed mRNAs were largely enriched in biological processes related to such activities as metabolism, immune activation, and stress,., and most genes were involved in pathways related to such phenomena as inflammation, cancer, signal transduction, and metabolism.

Conclusions

Our results clearly indicated that lncRNAs involved in responses to stimuli, multiorganism processes, development, reproductive processes and growth, are closely related to mammary gland development and lactation.

LncRNA LINC00857 regulates lung adenocarcinoma progression, apoptosis and glycolysis by targeting miR-1179/SPAG5 axis

Long non-coding RNA (lncRNA), a member of non-coding RNA family with over 200 nucleotides in length, typically serves as an oncogene or tumor suppressor in tumor progression, such as cancer cell proliferation, apoptosis and glycolysis. Recent studies manifested lncRNA LINC00857 was involved in cell cycle regulation of lung cancer. Due to complicated networks in tumorigenesis, the potential roles of LINC00857 underlying lung cancer progression still need further investigation. In this study, we explored the expression of LINC00857 in lung adenocarcinoma (LUAD) tissues and LUAD cell lines and found a dramatical upregulation of LINC00857 compared with the adjacent normal lung tissues and BEAS-2B cell line, respectively. Then, LINC00857 knockdown led to the cell proliferation and glycolysis was repressed, while the apoptosis was elevated in LUAD cell lines. Furthermore, we identified a direct interaction between LINC00857 and miR-1179 in LUAD cells using bioinformatic method and report assay. Finally, we evidenced LINC00857 promoted cell growth and glycolysis and repressed apoptosis via sponging miR-1179 and further regulating sperm-associated antigen 5 (SPAG5) expression in LUAD cell lines. Hence, our results authenticated that lncRNA LINC00857 regulated the cell proliferation, glycolysis and apoptosis of LUAD cells mainly through targeting the miR-1179/SPAG5 axis, which might be a novel insight into lung cancer progression and provided a potential target for clinical treatment of LUAD patients.

lncRNAs combine and crosstalk with NSPc1 in ATRA-induced differentiation of U87 glioma cells

Nervous system polycomb 1 (NSPc1) is a member of the polycomb group (PcG) family of proteins and has been demonstrated to maintain the differentiation and pluripotency of stem cells. Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the control of pluripotency and differentiation in embryonic and pluripotent cells. In the present study, the expression levels of NSPc1 were associated with the malignant potential of various glioma cell lines. Additionally, lncRNAs were differentially expressed in glioblastoma cell lines. Following induced differentiation of U87 glioblastoma cells with all-trans retinoic acid, the expression levels of NSPc1 decreased initially, reaching its lowest point on day 6, but then subsequently increased until day 10. The expression of lncRNA candidates decreased in the cell differentiation stage. Additionally, the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), sex-determining region of the Y chromosome-box 2 overlapping transcript (SOX2OT) and antisense non-coding RNA in the INK4 locus (ANRIL) was significantly altered relative to the expression levels of NSPc1. RNA immunoprecipitation (RIP) assays demonstrated that MALAT1, SOX2OT and ANRIL bind to NSPc1 in U87 glioblastoma cells and the enrichment of ANRIL in anti-NSPc1 antibody group was associated with the expression levels of NSPc1 during U87 cell differentiation. Small interfering RNA mediated downregulation of NSPc1 expression with MALAT1, SOX2OT and ANRIL, inhibited the proliferation, and promoted apoptosis in U87 cells. The results of the present study demonstrate that MALAT1, SOX2OT and ANRIL combine and crosstalk with NSPc1 in U87 cells to affect proliferation and apoptosis.

Competing endogenous RNA network of endometrial carcinoma: A comprehensive analysis

Competing endogenous RNA (ceRNA) network is dysregulated in the initiation and progression of tumors. In the present study, we explored the regulatory mechanism of ceRNA in endometrial carcinoma (EC) and the potential key molecules with potential value in the diagnosis, treatment, and prognosis of EC. The long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) expression profiles (552 EC tissues and 35 nontumor tissues) and microRNAs (miRNAs) expression profiles (546 EC tissues and 33 nontumor tissues) were downloaded from The Cancer Genome Atlas database to identify differentially expressed RNAs (DERNAs) in EC. An integrated bioinformatics analysis was used to construct an EC-specific ceRNA network and select key molecules. As a result, 96 differentially expressed lncRNAs (DElncRNAs), 29 differentially expressed miRNAs (DEmiRNAs), and 77 differentially expressed mRNAs (DEmRNAs) were identified. An EC-specific ceRNA network was built based on nine DElncRNAs significantly associated with overall survival. CCNB1 was found as a key gene in EC through the weighted gene coexpression network analysis and protein-protein interaction network analysis. Our ceRNA network showed C2orf48 and LINC00483 might upregulate CCNB1 via competing with miR-183. In addition, we found a subnetwork which contained survival-associated DERNAs (AC110491.1, LINC00483-miR-192-GRHL1). The results of reverse transcription quantitative polymerase chain reaction supported the relative expressions of C2orf48, LINC00483 were upregulated and that of AC110491.1 was downregulated in EC. We further found C2orf48 was upregulated in serous EC, endometrioid EC, and mixed serous and endometrioid EC. LINC00483 was upregulated in mixed serous and endometrioid EC compared with that in the normal tissues according to UALCAN database. In addition, candidate small molecular drugs were screened out by ConnectivityMap based on the 77 DEmRNAs in the ceRNA network. Eventually, C2orf48, LINC00483, and AC110491.1 were identified as three key lncRNAs in EC.

Long Noncoding RNAs in Colorectal Adenocarcinoma; an in silico Analysis

Long noncoding RNAs (lncRNAs) are lengthy noncoding transcripts which are involved in critical signaling pathways including cell cycle and apoptosis so it is not surprising to see their altered expression in human tumors. Colorectal adenocarcinoma is one the most frequent malignancies worldwide. The role of lncRNAs in colorectal adenocarcinoma is not well understood. To study the significance of lncRNAs in colorectal adenocarcinoma, we retrieved 189 approved lncRNAs from HGNC. The genes were imported into the cBioPortal database for transcriptomic analyses. We queried all the samples from TCGA provisional colorectal adenocarcinoma with RNA-seq v2 data in our study and considered RNA dysregulation with Z-score: ±2. The lncRNA which was altered in most of the patients were considered as "significant lncRNA" for further analyses. We considered the association of candidate lncRNAs with clinicopathologic parameters of samples including tumor disease anatomic site, neoplasm histologic types, tumor stage and survival. We also compute the specificity of the significant lncRNAs expression in colorectal adenocarcinoma comparing with other human cancers in cancer portal. Our analysis showed that lncRNAs SNHG6, PVT1 and ZFAS1 allocated the maximum alteration among the colorectal cases. The expression of SNHG6 and ZFAS1 was more in rectal adenocarcinoma than the colon carcinoma while the PVT1 showed the same expression levels in both tissues. However, we found that upregulation of PVT1 has been reduced the overall survival in patients. Altogether these data showed SNHG6, PVT1 and ZFAS1, are promising candidates for experimental research on colorectal adenocarcinoma to discover novel biomarker for this prevalent cancer.

Prognostic and clinicopathological role of long non-coding RNA UCA1 in various carcinomas

Urothelial cancer associated 1 (UCA1) as an oncogenic long non-coding RNA (LncRNA) was aberrantly upregulated in various solid tumors. Numerous studies have demonstrated overexpression of UCA1 is an unfavorable prognostic indicator in cancer patients. This study aimed to further explore the prognosis role and clinical significance of UCA1 in cancer. Eligible studies were recruited by a systematic search in PubMed, Embase, Cochrane Library and Web of Science databases. A total of 19/16 studies with 1587/1291 cancer patients were included to evaluate the association between UCA1 expression and overall survival (OS) and clinicopathological factors of malignancies by computing hazard ratio (HR), odds ratios (OR) and confidence interval (CI). The meta-analysis indicated overexpression of UCA1 was significantly correlated with unexpected OS in patients with cancer (pooled HR = 1.85, 95% CI 1.62-2.10, p < 0.001). There was also a significantly negative association between high level of UCA1 and poor grade cancer (pooled OR = 2.74, 95% CI 2.04-3.70, p < 0.001) and positive lymphatic metastasis (pooled OR = 2.43, 95% CI 1.72-3.41, p < 0.001). In conclusion, our study suggested that UCA1 was correlated with more advanced clinicopathological features and poor prognosis as a novel predictive biomarker of patients with various tumors.

Regulation of neuronal-glial fate specification by long non-coding RNAs

Neural stem cell transplantation is becoming a promising and attractive cell-based treatment modality for repairing the damaged central nervous system. One of the limitations of this approach is that the proportion of functional cells differentiated from stem cells still remains at a low level. In recent years, novel long non-coding RNAs (lncRNAs) are being discovered at a growing pace, suggesting that this class of molecules may act as novel regulators in neuronal-glial fate specification. In this review, we first describe the general features of lncRNAs that are more likely to be relevant to reveal their function. By this, we aim to point out the specific roles of a number of lncRNAs whose function has been described during neuronal and glial cell differentiation. There is no doubt that investigation of the lncRNAs will open a new window in studying neuronal-glial fate specification.

Reconstructing evolutionary trees in parallel for massive sequences

BACKGROUND

Building the evolutionary trees for massive unaligned DNA sequences is challenging and crucial. However, reconstructing evolutionary tree for ultra-large sequences is hard. Massive multiple sequence alignment is also challenging and time/space consuming. Hadoop and Spark are developed recently, which bring spring light for the classical computational biology problems. In this paper, we tried to solve the multiple sequence alignment and evolutionary reconstruction in parallel.

RESULTS

HPTree, which is developed in this paper, can deal with big DNA sequence files quickly. It works well on the >1GB files, and gets better performance than other evolutionary reconstruction tools. Users could use HPTree for reonstructing evolutioanry trees on the computer clusters or cloud platform (eg. Amazon Cloud). HPTree could help on population evolution research and metagenomics analysis.

CONCLUSIONS

In this paper, we employ the Hadoop and Spark platform and design an evolutionary tree reconstruction software tool for unaligned massive DNA sequences. Clustering and multiple sequence alignment are done in parallel. Neighbour-joining model was employed for the evolutionary tree building. We opened our software together with source codes via http://lab.malab.cn/soft/HPtree/ .

Histone code and long non-coding RNAs (lncRNAs) aberrations in lung cancer: implications in the therapy response

Respiratory diseases hold several genome, epigenome, and transcriptional aberrations as a cause of the accumulated damage promoted by, among others, environmental risk factors. Such aberrations can also come about as an adaptive response when faced with therapeutic oncological drugs. In epigenetic terms, aberrations in DNA methylation patterns, histone code marks balance, and/or chromatin-remodeling complexes recruitment, among Polycomb Repressive Complex-2 (PRC2) versus Trithorax (TRX) Activator Complex, have been proposed to be affected by several previously characterized functional long non-coding RNAs (lncRNAs). Such molecules are involved in modulating and/or controlling lung cancer epigenome and genome expression, as well as in malignancy and clinical progression in lung cancer. Several recent reports have described diverse epigenetic modifications in lung cancer cells and solid tumors, among others genomic DNA methylation and post-translational modifications (PTMs) on histone tails, as well as lncRNAs patterns and levels of expression. However, few systematic approaches have attempted to demonstrate a biological function and clinical association, aiming to improve therapeutic decisions in basic research and lung clinical oncology. A widely used example is the lncRNA HOTAIR and its functional histone mark H3K27me3, which is directly associated to the PRC2; however, few systematic pieces of solid evidence have been experimentally performed, conducted and/or validated to predict lung oncological therapeutic efficacy. Recent evidence suggests that chromatin-remodeling complexes accompanied by lncRNAs profiles are involved in several comprehensive lung carcinoma clinical parameters, including histopathology progression, prognosis, and/or responsiveness to unique or combined oncological therapies. The present manuscript offers a systematic revision of the current knowledge about the major epigenetic aberrations represented by changes in histone PTMs and lncRNAs expression levels and patterns in human lung carcinomas in cancer drug-based treatments, as an important comprehensive knowledge focusing on better oncological therapies. In addition, a new future direction must be refocusing on several gene target therapies, mainly on pharmaceutical EGFR-TKIs compounds, widely applied in lung cancer, currently the leading cause of death by malignant diseases.

Novel atherogenic pathways from the differential transcriptome analysis of diabetic epicardial adipose tissue

BACKGROUND AND AIM

To evaluate the epicardial adipose tissue (EAT) transcriptome in comparison to subcutaneous fat (SAT) in coronary artery disease (CAD) and type 2 diabetes (T2DM).

METHODS AND RESULTS

SAT and EAT samples were obtained from subjects with T2DM and CAD (n = 5) and those without CAD with or without T2DM (=3) undergoing elective cardiac surgery. RNA-sequencing analysis was performed in both EAT and SAT. Gene enrichment analysis was conducted to identify pathways affected by the differentially expressed genes. Changes of top genes were verified by quantitative RT-PCR (qRT-PCR), western blot, and immunofluorescence. A total of 592 genes were differentially expressed in diabetic EAT, whereas there was no obvious changes in SAT transcriptome between diabetics and non-diabetics. Diabetic EAT was mainly enriched in inflammatory genes, such as Colony Stimulating Factor 3 (CSF3), Interleukin-1b (IL-1b), IL-6. KEGG pathway analysis confirmed that upregulated genes were involved in inflammatory pathways, such as Tumor Necrosis Factor (TNF), Nuclear Factor-κB (NF-κB) and advanced glycation end-products-receptor advanced glycation end products (AGE-RAGE). The overexpression of inflammatory genes in diabetic EAT was largely correlated with upregulated transcription factors such as NF-κB and FOS.

CONCLUSIONS

Diabetic EAT transcriptome is significantly different when compared to diabetic SAT and highly enriched with genes involved in innate immune response and endothelium, like Pentraxin3 (PTX3) and Endothelial lipase G (LIPG). EAT inflammatory genes expression could be induced by upregulated transcription factors, mainly NF-kB and FOSL, primarily activated by the overexpressed AGE-RAGE signaling. This suggests a unique and novel atherogenic pathway in diabetes.

The Critical Role of Long Noncoding RNA in Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells

Objective. Long noncoding RNAs (lncRNAs) have been demonstrated to regulate many biological processes including differentiation. However, their role in osteogenic differentiation was poorly known. Materials and Methods. In this study, we first globally profiled the differentially expressed lncRNAs and mRNAs during osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMMSCs). Bioinformatics analysis was performed to further analyze these significantly changed molecules. Then the role of lncRNA ENST00000502125.2 in the osteogenic differentiation was determined. Results. A number of lncRNAs and mRNAs were significantly differentially expressed during hBMMSC osteogenic differentiation. Among them, 433 lncRNAs and 956 mRNAs were continuously upregulated, while 232 lncRNAs and 229 mRNAs were continuously downregulated. Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that carbohydrate derivative binding and complement and coagulation cascades were most correlated molecular function and pathway, respectively. Downregulation of lncRNA ENST00000502125.2 promoted the osteogenic differentiation of hBMMSCs, and opposite results were found when lncRNA ENST00000502125.2 was upregulated. Conclusions. lncRNAs play a critical role in the osteogenic differentiation of hBMMSCs and targeting lncRNA ENST00000502125.2 might be a promising strategy to promote osteogenic differentiation.

Overexpression of FAM83H-AS1 indicates poor patient survival and knockdown impairs cell proliferation and invasion via MET/EGFR signaling in lung cancer

Whole transcriptome analyses of next generation RNA sequencing (RNA-Seq) data from human cancer samples reveled thousands of uncharacterized non-coding RNAs including long non-coding RNA (lncRNA). Recent studies indicated that lncRNAs are emerging as crucial regulators in cancer processes and potentially useful as biomarkers for cancer diagnosis and prognosis. To delineate dysregulated lncRNAs in lung cancer, we analyzed RNA-Seq data from 461 lung adenocarcinomas (LUAD) and 156 normal lung tissues. FAM83H-AS1, one of the top dysregulated lncRNAs, was found to be overexpressed in tumors relative to normal lung and significantly associated with worse patient survival in LUAD. We verified this diagnostic/prognostic potential in an independent cohort of LUAD by qRT-PCR. Cell proliferation, migration and invasion were decreased after FAM83H-AS1 knockdown using siRNAs in lung cancer cells. Flow cytometry analysis indicated the cell cycle was arrested at the G2 phase after FAM83H-AS1 knockdown. Mechanistically, we found that MET/EGFR signaling was regulated by FAM83H-AS1. Our study indicated that FAM83H-AS1 plays an important role in lung tumor progression and may be potentially used as diagnostic/prognostic marker. Further characterization of this lncRNA may provide a novel therapeutic target impacting MET/EGFR signaling.

Global profiling of viral and cellular non-coding RNAs in Epstein-Barr virus-induced lymphoblastoid cell lines and released exosome cargos

The human EBV-transformed lymphoblastoid cell line (LCL), obtained by infecting peripheral blood monocular cells with Epstein-Barr Virus, has been extensively used for human genetic, pharmacogenomic, and immunologic studies. Recently, the role of exosomes has also been indicated as crucial in the crosstalk between EBV and the host microenvironment. Because the role that the LCL and LCL exosomal cargo might play in maintaining persistent infection, and since little is known regarding the non-coding RNAs of LCL, the aim of our work was the comprehensive characterization of this class of RNA, cellular and viral miRNAs, and cellular lncRNAs, in LCL compared with PBMC derived from the same donors. In this study, we have demonstrated, for the first time, that all the viral miRNAs expressed by LCL are also packaged in the exosomes, and we found that two miRNAs, ebv-miR-BART3 and ebv-miR-BHRF1-1, are more abundant in the exosomes, suggesting a microvescicular viral microRNA transfer. In addition, lncRNA profiling revealed that LCLs were enriched in lncRNA H19 and H19 antisense, and released these through exosomes, suggesting a leading role in the regulation of the tumor microenvironment.

Over-expression of the long non-coding RNA HOTTIP inhibits glioma cell growth by BRE

Background

Gliomas are the most common type of primary brain tumour in the central nervous system of adults. The long non-coding RNA (lncRNA) HOXA transcript at the distal tip (HOTTIP) is transcribed from the 5′ tip of the HOXA locus. HOTTIP has recently been shown to be dysregulated and play an important role in the progression of several cancers. However, little is known about whether and how HOTTIP regulates glioma development.

Methods

In this study, we assayed the expression of HOTTIP in glioma tissue samples and glioma cell lines using real-time polymerase chain reaction and defined the biological functions of HOTTIP using the CCK-8 assay, flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL assay) and tumour formation assay in a nude mouse model. Finally, we discovered the underlying mechanism using the Apoptosis PCR 384HT Array, Western blot, RNA immunoprecipitation (RIP) and luciferase reporter assay.

Results

HOTTIP was aberrantly down-regulated in glioma tissues and glioma cell lines (U87-MG, U118-MG, U251 and A172), and over-expression of HOTTIP inhibited the growth of glioma cell lines in vitro and in vivo. Furthermore, HOTTIP could directly bind to the brain and reproductive expression (BRE) gene and down-regulate BRE gene expression. In addition, we further verified that over-expression of the BRE gene promoted the growth of glioma cell lines in vitro. Finally, over-expression of HOTTIP significantly suppressed the expression of the cyclin A and CDK2 proteins and increased the expression of the P53 protein. However, we found that the over-expression of BRE significantly increased the expression of the cyclin A and CDK2 proteins and suppressed the expression of the P53 protein. Taken together, these findings suggested that high levels of HOTTIP reduced glioma cell growth. Additionally, the mechanism of HOTTIP-mediated reduction of glioma cell growth may involve the suppression of cyclin A and CDK2 protein expression, which increases P53 protein expression via the down-regulation of BRE.

Conclusions

Our studies demonstrated that over-expression of HOTTIP promotes cell apoptosis and inhibits cell growth in U118-MG and U87-MG human glioma cell lines by down-regulating BRE expression to regulate the expression of P53, CDK2 and Cyclin A proteins. The data described in this study indicate that HOTTIP is an interesting candidate for further functional studies in glioma and demonstrate the potential application of HOTTIP in glioma therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0431-y) contains supplementary material, which is available to authorized users.

A genetic algorithm-based weighted ensemble method for predicting transposon-derived piRNAs

BACKGROUND

Predicting piwi-interacting RNA (piRNA) is an important topic in the small non-coding RNAs, which provides clues for understanding the generation mechanism of gamete. To the best of our knowledge, several machine learning approaches have been proposed for the piRNA prediction, but there is still room for improvements.

RESULTS

In this paper, we develop a genetic algorithm-based weighted ensemble method for predicting transposon-derived piRNAs. We construct datasets for three species: Human, Mouse and Drosophila. For each species, we compile the balanced dataset and imbalanced dataset, and thus obtain six datasets to build and evaluate prediction models. In the computational experiments, the genetic algorithm-based weighted ensemble method achieves 10-fold cross validation AUC of 0.932, 0.937 and 0.995 on the balanced Human dataset, Mouse dataset and Drosophila dataset, respectively, and achieves AUC of 0.935, 0.939 and 0.996 on the imbalanced datasets of three species. Further, we use the prediction models trained on the Mouse dataset to identify piRNAs of other species, and the models demonstrate the good performances in the cross-species prediction.

CONCLUSIONS

Compared with other state-of-the-art methods, our method can lead to better performances. In conclusion, the proposed method is promising for the transposon-derived piRNA prediction. The source codes and datasets are available in https://github.com/zw9977129/piRNAPredictor .

Annotating the Function of the Human Genome with Gene Ontology and Disease Ontology

Increasing evidences indicated that function annotation of human genome in molecular level and phenotype level is very important for systematic analysis of genes. In this study, we presented a framework named Gene2Function to annotate Gene Reference into Functions (GeneRIFs), in which each functional description of GeneRIFs could be annotated by a text mining tool Open Biomedical Annotator (OBA), and each Entrez gene could be mapped to Human Genome Organisation Gene Nomenclature Committee (HGNC) gene symbol. After annotating all the records about human genes of GeneRIFs, 288,869 associations between 13,148 mRNAs and 7,182 terms, 9,496 associations between 948 microRNAs and 533 terms, and 901 associations between 139 long noncoding RNAs (lncRNAs) and 297 terms were obtained as a comprehensive annotation resource of human genome. High consistency of term frequency of individual gene (Pearson correlation = 0.6401, p = 2.2e - 16) and gene frequency of individual term (Pearson correlation = 0.1298, p = 3.686e - 14) in GeneRIFs and GOA shows our annotation resource is very reliable.

BP Neural Network Could Help Improve Pre-miRNA Identification in Various Species

MicroRNAs (miRNAs) are a set of short (21–24 nt) noncoding RNAs that play significant regulatory roles in cells. In the past few years, research on miRNA-related problems has become a hot field of bioinformatics because of miRNAs' essential biological function. miRNA-related bioinformatics analysis is beneficial in several aspects, including the functions of miRNAs and other genes, the regulatory network between miRNAs and their target mRNAs, and even biological evolution. Distinguishing miRNA precursors from other hairpin-like sequences is important and is an essential procedure in detecting novel microRNAs. In this study, we employed backpropagation (BP) neural network together with 98-dimensional novel features for microRNA precursor identification. Results show that the precision and recall of our method are 95.53% and 96.67%, respectively. Results further demonstrate that the total prediction accuracy of our method is nearly 13.17% greater than the state-of-the-art microRNA precursor prediction software tools.

Dynamic mRNA and miRNA expression analysis in response to intermuscular bone development of blunt snout bream (Megalobrama amblycephala)

Intermuscular bone (IB), which occurs only in the myosepta of lower teleosts, is attracting more attention because they are difficult to remove and make the fish unpleasant to eat. By gaining a better understanding of the genetic regulation of IB development, an integrated analysis of miRNAs and mRNAs expression profiling was performed on Megalobrama amblycephala. Four key development stages were selected for transcriptome and small RNA sequencing. A number of significantly differentially expressed miRNAs/genes associated with bone formation and differentiation were identified and the functional characteristics of these miRNAs/genes were revealed by GO function and KEGG pathway analysis. These were involved in TGF-β, ERK and osteoclast differentiation pathways known in the literature to affect bone formation and differentiation. MiRNA-mRNA interaction pairs were detected from comparison of expression between different stages. The function annotation results also showed that many miRNA-mRNA interaction pairs were likely to be involved in regulating bone development and differentiation. A negative regulation effect of two miRNAs was verified through dual luciferase reporter assay. As a unique public resource for gene expression and regulation during the IB development, this study is expected to provide forwards ideas and resources for further biological researches to understand the IBs’ development.

Long noncoding NONRATT021972 siRNA normalized abnormal sympathetic activity mediated by the upregulation of P2X7 receptor in superior cervical ganglia after myocardial ischemia

Previous studies showed that the upregulation of the P2X7 receptor in cervical sympathetic ganglia was involved in myocardial ischemic (MI) injury. The dysregulated expression of long noncoding RNAs (lncRNAs) participates in the onset and progression of many pathological conditions. The aim of this study was to investigate the effects of a small interfering RNA (siRNA) against the NONRATT021972 lncRNA on the abnormal changes of cardiac function mediated by the up-regulation of the P2X7 receptor in the superior cervical ganglia (SCG) after myocardial ischemia. When the MI rats were treated with NONRATT021972 siRNA, their increased systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), low-frequency (LF) power, and LF/HF ratio were reduced to normal levels. However, the decreased high-frequency (HF) power was increased. GAP43 and tyrosine hydroxylase (TH) are markers of nerve sprouting and sympathetic nerve fibers, respectively. We found that the TH/GAP43 value was significantly increased in the MI group. However, it was reduced after the MI rats were treated with NONRATT021972 siRNA. The serum norepinephrine (NE) and epinephrine (EPI) concentrations were decreased in the MI rats that were treated with NONRATT021972 siRNA. Meanwhile, the increased P2X7 mRNA and protein levels and the increased p-ERK1/2 expression in the SCG were also reduced. NONRATT021972 siRNA treatment inhibited the P2X7 agonist BzATP-activated currents in HEK293 cells transfected with pEGFP-P2X7. Our findings suggest that NONRATT021972 siRNA could decrease the upregulation of the P2X7 receptor and improve the abnormal changes in cardiac function after myocardial ischemia.

Accurate Prediction of Transposon-Derived piRNAs by Integrating Various Sequential and Physicochemical Features

BACKGROUND

Piwi-interacting RNA (piRNA) is the largest class of small non-coding RNA molecules. The transposon-derived piRNA prediction can enrich the research contents of small ncRNAs as well as help to further understand generation mechanism of gamete.

METHODS

In this paper, we attempt to differentiate transposon-derived piRNAs from non-piRNAs based on their sequential and physicochemical features by using machine learning methods. We explore six sequence-derived features, i.e. spectrum profile, mismatch profile, subsequence profile, position-specific scoring matrix, pseudo dinucleotide composition and local structure-sequence triplet elements, and systematically evaluate their performances for transposon-derived piRNA prediction. Finally, we consider two approaches: direct combination and ensemble learning to integrate useful features and achieve high-accuracy prediction models.

RESULTS

We construct three datasets, covering three species: Human, Mouse and Drosophila, and evaluate the performances of prediction models by 10-fold cross validation. In the computational experiments, direct combination models achieve AUC of 0.917, 0.922 and 0.992 on Human, Mouse and Drosophila, respectively; ensemble learning models achieve AUC of 0.922, 0.926 and 0.994 on the three datasets.

CONCLUSIONS

Compared with other state-of-the-art methods, our methods can lead to better performances. In conclusion, the proposed methods are promising for the transposon-derived piRNA prediction. The source codes and datasets are available in S1 File.

Long Noncoding RNAs as Novel Biomarkers Have a Promising Future in Cancer Diagnostics

Cancers have a high mortality rate due to lack of suitable specific early diagnosis tumor biomarkers. Emerging evidence is accumulating that lncRNAs (long noncoding RNAs) are involved in tumorigenesis, tumor cells proliferation, invasion, migration, apoptosis, and angiogenesis. Furthermore, extracellular lncRNAs can circulate in body fluids; they can be detected and strongly resist RNases. Many researchers have found that lncRNAs could be good candidates for tumor biomarkers and possessed high specificity, high sensitivity, and noninvasive characteristics. In this review, we summarize the detection methods and possible sources of circulating lncRNAs and outline the biological functions and expression level of the most significant lncRNAs in tissues, cell lines, and body fluids (whole blood, plasma, urine, gastric juice, and saliva) of different kinds of tumors. We evaluate the diagnostic performance of lncRNAs as tumor biomarkers. However, the biological functions and the mechanisms of circulating lncRNAs secretion have not been fully understood. The uniform normalization protocol of sample collection, lncRNAs extraction, endogenous control selection, quality assessment, and quantitative data analysis has not been established. Therefore, we put forward some recommendations that might be investigated in the future if we want to adopt lncRNAs in clinical practice.

The long non-coding RNA expression profile of Coxsackievirus A16 infected RD cells identified by RNA-seq

Coxsackievirus A16 (CVA16) is one of major pathogens of hand, foot and mouth disease (HFMD) in children. Long non-coding RNAs (IncRNAs) have been implicated in various biological processes, but they have not been associated with CVA16 infection. In this study, we comprehensively characterized the landscape of IncRNAs of normal and CVA16 infected rhabdomyosarcoma (RD) cells using RNA-Seq to investigate the functional relevance of IncRNAs. We showed that a total of 760 IncRNAs were upregulated and 1210 IncRNAs were downregulated. Out of these dysregulated IncRNAs, 43.64% were intergenic, 22.31% were sense, 15.89% were intronic, 8.67% were bidirectional, 5.59% were antisense, 3.85% were sRNA host IncRNAs and 0.05% were enhancer. Six dysregulated IncRNAs were validated by quantitative PCR assays and the secondary structures of these IncRNAs were projected. Moreover, we conducted a bioinformatics analysis of an IncRNAs (ENST00000602478) to elucidate the diversity of modification and functions of IncRNAs. In summary, the current study compared the dysregulated IncRNAs profile upon CVA16 challenge and illustrated the intricate relationship between coding and IncRNAs transcripts. These results may not only provide a complete picture of transcription in CVA16 infected cells but also provide novel molecular targets for treatments of HFMD.

Non-coding RNA LINC00857 is predictive of poor patient survival and promotes tumor progression via cell cycle regulation in lung cancer

We employed next generation RNA sequencing analysis to reveal dysregulated long non-coding RNAs (lncRNAs) in lung cancer utilizing 461 lung adenocarcinomas (LUAD) and 156 normal lung tissues from 3 separate institutions. We identified 281 lncRNAs with significant differential-expression between LUAD and normal lung tissue. LINC00857, a top deregulated lncRNAs, was overexpressed in tumors and significantly associated with poor survival in LUAD. knockdown of LINC00857 with siRNAs decreased tumor cell proliferation, colony formation, migration and invasion in vitro, as well as tumor growth in vivo. Overexpression of LINC00857 increased cancer cell proliferation, colony formation and invasion. Mechanistic analyses indicated that LINC00857 mediates tumor progression via cell cycle regulation. Our study highlights the diagnostic/prognostic potential of LINC00857 in LUAD besides delineating the functional and mechanistic aspects of its aberrant disease specific expression and potentially using as a new therapeutic target.