Exploring the secrets of long noncoding RNAs. Int J Mol Sci. 2015;16:5467-5496. [PMID: 25764159 PMCID: PMC4394487 DOI: 10.3390/ijms16035467]

Comprehensive expression, prognostic and validation analysis of necroptosis-related lncRNAs in esophageal cancer

BACKGROUND

Previous studies have shown that necroptosis-related long noncoding RNA (lncRNA) risk models can be used to predict prognosis and immune infiltration in patients with esophageal cancer. However, further analysis of the regulatory mechanisms of necroptosis-related lncRNAs used in risk models remains to be conducted. The purpose of the present study was to identify valuable necroptosis-related lncRNAs in esophageal cancer and to verify their molecular and cellular functions.

METHODS

Esophageal cancer data were downloaded from The Cancer Genome Atlas (TCGA). The expression of eight genes (LINC00299, AC090912.2, AC244197.2, AL158166.1, AC079684.1, AP003696.1, AC079684.1 and AP003696.1) in the necroptosis-related lncRNA risk model, their relationships with clinicopathological stage, and their diagnostic receiver operating characteristic (ROC) curves were analyzed. The prognostic value of these lncRNAs for overall survival (OS) and disease specific survival (DSS) was analyzed, and time-dependent ROC curves were generated. The AP003696.1 target gene (lncRNA ENSG00000253385.1) was further investigated through immune infiltration analysis, Gene Ontology/Kyoto Encyclopedia of Genes and Genomes (GO/KEGG) enrichment analyses, and gene coexpression analysis. Finally, in vitro functional assays based on lncRNA ENSG00000253385.1 were conducted to explore its regulatory role in esophageal cancer.

RESULTS

A bioinformatics approach was used to study the eight genes in the necroptosis-related lncRNA risk model. AP003696.1 (lncRNA ENSG00000253385.1) was highly expressed in esophageal cancer tissues, and its high expression was correlated with poor OS and DFdS. Both univariate and multivariate Cox regression analyses revealed that lncRNA ENSG00000253385.1 is an independent prognostic factor. The lncRNA ENSG00000253385.1 gene was demonstrated to play a definite role in the invasion of esophageal cancer immune cells and in signaling pathways in these cells. In vitro cell functional assays revealed that lncRNA ENSG00000253385.1 expression was elevated in the KYSE150 and KYSE410 esophageal cancer cell lines. Small interfering RNA (siRNA)-mediated silencing of lncRNA ENSG00000253385.1 significantly inhibited the proliferation, migration, and invasion of KYSE150 and KYSE410 cells, as well as promoted their apoptosis.

CONCLUSIONS

The ENSG00000253385.1 gene may be a key gene in the occurrence, development, and prognosis of esophageal cancer. These findings provide new ideas and references for the screening of therapeutic targets, as well as the development of targeted drugs, for esophageal cancer treatment.

The response of LncRNAs associated with photosynthesis-and pigment synthesis-related genes to green light in Chlamydomonas reinhardtii

The quality of light is an important abiotic factor that affects the growth and development of green plants. Ultraviolet, red, blue, and far-red light all have demonstrated roles in regulating green plant growth and development, as well as light morphogenesis. However, the mechanism underlying photosynthetic organism responses to green light throughout the life of them are not clear. In this study, we exposed the unicellular green alga Chlamydomonas reinhardtii to green light and analyzed the dynamics of transcriptome changes. Based on the whole transcriptome data from C. reinhardtii, a total of 9974 differentially expressed genes (DEGs) were identified under green light. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that these DEGs were mainly related to "carboxylic acid metabolic process," "enzyme activity," "carbon metabolism," and "photosynthesis and other processes." At the same time, 253 differentially expressed long non-coding RNAs (DELs) were characterized as green light responsive. We also made a detailed analysis of the responses of photosynthesis- and pigment synthesis-related genes in C. reinhardtii to green light and found that these genes exhibited obvious dynamic expression. Lastly, we constructed a co-expression regulatory network, comprising 49 long non-coding RNAs (lncRNAs) and 20 photosynthesis and pigment related genes, of which 9 mRNAs were also the predicted trans/cis-targets of 8 lncRNAs, these results suggested that lncRNAs may affect the expression of mRNAs related to photosynthesis and pigment synthesis. Our findings give a preliminary explanation of the response mechanism of C. reinhardtii to green light at the transcriptional level.

LncRNA CARMN facilitates odontogenic differentiation of dental pulp cells by impairing EZH2

OBJECTIVE

This study aimed to reveal the potential role of CARMN in odontogenic differentiation of dental pulp cells (DPCs).

METHODS

Laser capture microdissection was used to detect Carmn in DPCs and odontoblasts in P0 mice. After manipulating CARMN expression in odontogenic differentiation induced hDPCs, the state of odontogenic differentiation was evaluated by ALP staining, ARS, and related marker expression in qRT-PCR and western blotting. The subcutaneous transplantation of HA/β-TCP loaded with hDPCs was performed to verify CARMN's role in promoting odontogenic differentiation in vivo. RNAplex and RIP were employed to reveal potential mechanism of CARMN in hDPCs.

RESULTS

CARMN expressed more abundantly in odontoblasts than DPCs in P0 mice. CARMN expression boosted during in vitro odontogenic differentiation of hDPCs. CARMN overexpression enhanced odontogenic differentiation of hDPCs in vitro, while inhibition impaired the process. CARMN overexpression in HA/β-TCP composites promoted more mineralized nodule formation in vivo. CARMN knockdown led to soared EZH2, while CARMN overexpression brought about EZH2 inhibition. CARMN functioned via direct interaction with EZH2.

CONCLUSIONS

The results uncovered CARMN as a modulator during the odontogenic differentiation of DPCs. CARMN promoted odontogenic differentiation of DPCs by impairing EZH2.

The expression and function of long noncoding RNAs in hepatocellular carcinoma

With the deepening of the genome project study, attention on noncoding RNAs is increasing. Long noncoding RNAs (lncRNAs) have become a new research hotspot. A growing number of studies have revealed that lncRNAs are involved in tumorigenesis and tumor suppressor pathways. Aberrant expressions of lncRNAs have been found in a variety of human tumors including hepatocellular carcinoma (HCC). In this review, we provide a brief introduction to lncRNA and highlight recent research on the functions and clinical significance of lncRNAs in HCC.

Genome-wide identification of long non-coding RNAs and their potential functions in radish response to salt stress

Long non-coding RNAs (lncRNAs) are increasingly recognized as cis- and trans-acting regulators of protein-coding genes in plants, particularly in response to abiotic stressors. Among these stressors, high soil salinity poses a significant challenge to crop productivity. Radish (Raphanus sativus L.) is a prominent root vegetable crop that exhibits moderate susceptibility to salt stress, particularly during the seedling stage. Nevertheless, the precise regulatory mechanisms through which lncRNAs contribute to salt response in radish remain largely unexplored. In this study, we performed genome-wide identification of lncRNAs using strand-specific RNA sequencing on radish fleshy root samples subjected to varying time points of salinity treatment. A total of 7,709 novel lncRNAs were identified, with 363 of them displaying significant differential expression in response to salt application. Furthermore, through target gene prediction, 5,006 cis- and 5,983 trans-target genes were obtained for the differentially expressed lncRNAs. The predicted target genes of these salt-responsive lncRNAs exhibited strong associations with various plant defense mechanisms, including signal perception and transduction, transcription regulation, ion homeostasis, osmoregulation, reactive oxygen species scavenging, photosynthesis, phytohormone regulation, and kinase activity. Notably, this study represents the first comprehensive genome-wide analysis of salt-responsive lncRNAs in radish, to the best of our knowledge. These findings provide a basis for future functional analysis of lncRNAs implicated in the defense response of radish against high salinity, which will aid in further understanding the regulatory mechanisms underlying radish response to salt stress.

Evaluation of efficacy of non-coding RNA in abiotic stress management of field crops: Current status and future prospective

Abiotic stresses are responsible for the major losses in crop yield all over the world. Stresses generate harmful ROS which can impair cellular processes in plants. Therefore, plants have evolved antioxidant systems in defence against the stress-induced damages. The frequency of occurrence of abiotic stressors has increased several-fold due to the climate change experienced in recent times and projected for the future. This had particularly aggravated the risk of yield losses and threatened global food security. Non-coding RNAs are the part of eukaryotic genome that does not code for any proteins. However, they have been recently found to have a crucial role in the responses of plants to both abiotic and biotic stresses. There are different types of ncRNAs, for example, miRNAs and lncRNAs, which have the potential to regulate the expression of stress-related genes at the levels of transcription, post-transcription, and translation of proteins. The lncRNAs are also able to impart their epigenetic effects on the target genes through the alteration of the status of histone modification and organization of the chromatins. The current review attempts to deliver a comprehensive account of the role of ncRNAs in the regulation of plants' abiotic stress responses through ROS homeostasis. The potential applications ncRNAs in amelioration of abiotic stresses in field crops also have been evaluated.

Molecular Regulatory Mechanisms in Chicken Feather Follicle Morphogenesis

In China, the sale of freshly slaughtered chickens is becoming increasingly popular in comparison with that of live chickens, and due to this emerging trend, the skin and feather follicle traits of yellow-feathered broilers have attracted a great deal of research attention. The feather follicle originates from the interaction between the epidermis and dermis in the early embryonic stage. Feather follicle morphogenesis is regulated by the Wnt, ectodysplasin (Eda), epidermal growth factor (EGF), fibroblast growth factor (FGF), bone morphogenetic protein (BMP), sonic hedgehog (Shh), Notch, and other signaling pathways that exist in epithelial and mesenchymal cells. The Wnt pathway is essential for feather follicle and feather morphogenesis. Eda interacts with Wnt to induce FGF expression, which attracts mesenchymal cell movement and aggregates to form feather follicle primordia. BMP acts as an inhibitor of the above signaling pathways to limit the size of the feather tract and distance between neighboring feather primordia in a dose-dependent manner. The Notch/Delta pathway can interact with the FGF pathway to promote feather bud formation. While not a part of the early morphogenesis of feather follicles, Shh and BMP signaling are involved in late feather branching. This review summarizes the roles of miRNAs/lncRNA in the regulation of feather follicle and feather growth and development and suggests topics that need to be solved in a future study. This review focuses on the regulatory mechanisms involved in feather follicle morphogenesis and analyzes the impact of SNP sites on feather follicle traits in poultry. This work may help us to understand the molecular regulatory networks influencing feather follicle growth and provide basic data for poultry carcass quality.

LncRNA PROX1 antisense RNA 1 promotes PD-L1-mediated proliferation, metastasis, and immune escape in colorectal cancer by interacting with miR-520d

It was recently found that lncRNA PROX1 antisense RNA 1 (PROX1-AS1) manifested oncogenicity in a variety of malignancies. This work intended to investigate the molecular mechanisms of PROX1-AS1 in colorectal cancer (CRC) development and immune evasion. In this study, both PROX1-AS1 and PD-L1 expressions were lifted in CRC tissues and cells. PROX1-AS1 interference restrained CRC cell proliferation, migration, invasion, as well as CD8 + T-lymphocyte apoptosis, but increased the cytotoxicity and percentage of CD8 + T lymphocytes. The inhibitory effects of PROX1-AS1 inhibition on CRC progression and immune escape were positively related to PD-L1 suppression. PROX1-AS1 absorbed miR-520d to upregulate PD-L1 expression. PROX1-AS1 facilitated CRC progression and immune escape by targeting miR-520d. Furthermore, PROX1-AS1 deletion impaired CRC tumor growth in vivo . To sum up, this study affirmed that PROX1-AS1 could absorb miR-520d to upregulate PD-L1 in CRC, thereby promoting tumor progression and immune escape.

LncRNA NR_003508 Suppresses Mycobacterium tuberculosis-Induced Programmed Necrosis via Sponging miR-346-3p to Regulate RIPK1

Emerging evidence suggests that long non-coding RNAs (LncRNAs) are involved in Mtb-induced programmed necrosis. Among these LncRNAs, LncRNA NR_003508 is associated with LPS-induced acute respiratory distress syndrome. However, whether LncRNA NR_003508 contributes to Mtb-induced programmed necrosis remains undocumented. Firstly, the expression of LncRNA NR_003508 was determined using RT-qPCR and FISH. The protein expression of RIPK1, p-RIPK1, RIPK3, p-RIPK3, MLKL, and p-MLKL was measured by Western blot in RAW264.7 and mouse lung tissues. Furthermore, luciferase reporter assays and bioinformatics were used to predict specific miRNA (miR-346-3p) and mRNA (RIPK1) regulated by LncRNA NR_003508. In addition, RT-qPCR was used to detect the RIPK1 expression in TB patients and healthy peripheral blood. The flow cytometry assay was performed to detect cell necrosis rates. Here we show that BCG infection-induced cell necrosis and increased LncRNA NR_003508 expression. si-NR_003508 inhibited BCG/H37Rv-induced programmed necrosis in vitro or in vivo. Functionally, LncRNA NR_003508 has been verified as a ceRNA for absorbing miR-346-3p, which targets RIPK1. Moreover, RIPK1 expression was elevated in the peripheral blood of TB patients compared with healthy people. Knockdown of LncRNA NR_003508 or miR-346-3p overexpression suppresses cell necrosis rate and ROS accumulation in RAW264.7 cells. In conclusion, LncRNA NR_003508 functions as a positive regulator of Mtb-induced programmed necrosis via sponging miR-346-3p to regulate RIPK1. Our findings may provide a promising therapeutic target for tuberculosis.

Comprehensive investigation of long non-coding RNAs in an endophytic fungus Calcarisporium arbuscula NRRL 3705

Long non-coding RNAs (lncRNAs) play an important role in eukaryotic cells. However, there is no report of lncRNAs in endophytic fungi Calcarisporium arbuscula. Here, in Calcarisporium arbuscula NRRL 3705, an endophytic fungus predominantly producing mycotoxins aurovertins, the genome-wide identification of lncRNAs was carried out based on RNA-Seq. Totally, 1332 lncRNAs were identified, including 1082 long intergenic noncoding RNAs, 64 long intronic noncoding RNAs and 186 long noncoding natural antisense transcripts. The average length of lncRNA and mRNA were 254 and 1102 bp, respectively. LncRNAs were shorter, with fewer exons and lower expression levels. Moreover, there were 39 up-regulated lncRNAs and 10 down-regulated lncRNAs in the ΔaurA mutant, which lacks the aurovertin biosynthetic enzyme AurA. Interestingly, expression of genes related to the metabolism of linoleic acid and methane were significantly down regulated in the ΔaurA mutant. This study enriches the endophytic fungal lncRNA database and provide a basis for further research.

ASLncR: a novel computational tool for prediction of abiotic stress-responsive long non-coding RNAs in plants

Abiotic stresses are detrimental to plant growth and development and have a major negative impact on crop yields. A growing body of evidence indicates that a large number of long non-coding RNAs (lncRNAs) are key to many abiotic stress responses. Thus, identifying abiotic stress-responsive lncRNAs is essential in crop breeding programs in order to develop crop cultivars resistant to abiotic stresses. In this study, we have developed the first machine learning-based computational model for predicting abiotic stress-responsive lncRNAs. The lncRNA sequences which were responsive and non-responsive to abiotic stresses served as the two classes of the dataset for binary classification using the machine learning algorithms. The training dataset was created using 263 stress-responsive and 263 non-stress-responsive sequences, whereas the independent test set consists of 101 sequences from both classes. As the machine learning model can adopt only the numeric data, the Kmer features ranging from sizes 1 to 6 were utilized to represent lncRNAs in numeric form. To select important features, four different feature selection strategies were utilized. Among the seven learning algorithms, the support vector machine (SVM) achieved the highest cross-validation accuracy with the selected feature sets. The observed 5-fold cross-validation accuracy, AU-ROC, and AU-PRC were found to be 68.84, 72.78, and 75.86%, respectively. Furthermore, the robustness of the developed model (SVM with the selected feature) was evaluated using an independent test dataset, where the overall accuracy, AU-ROC, and AU-PRC were found to be 76.23, 87.71, and 88.49%, respectively. The developed computational approach was also implemented in an online prediction tool ASLncR accessible at https://iasri-sg.icar.gov.in/aslncr/ . The proposed computational model and the developed prediction tool are believed to supplement the existing effort for the identification of abiotic stress-responsive lncRNAs in plants.

IncRNA MALAT1 Regulates the Proliferation, Apoptosis, Migration, and Invasion of Osteosarcoma Cells by Targeting miR-873-5p/ROCK1

The malignant bone tumor osteosarcoma (OS) was one of the most aggressive tumors. Despite breakthroughs in treatment options for OS recently, the survival rate of patients with metastasis or reoccurring disease has remained unchanged over the last 25 years, at around 20%. lncRNA expression dysregulation is linked to carcinogenesis, advancement, and metastasis. Additionally, the fundamental mechanism of lncRNAs in regulating OS cell biological activity and progression is still being investigated. The expression of miR-873-5p and MALAT1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in OS. The relationship between the expression level of MALAT1 and the survival rate of OS individuals was evaluated by the Kaplan-Meier plotter. The tumor cell's capability of proliferation was determined using the CCK-8. Transwell was used to test the migratory and invasive properties of tumor cells. ROCK1 protein expression was analyzed by western blot, while qRT-PCR was used to detect ROCK1 mRNA expression. Targeted genes of MALAT1 or miR-873-5p were predicted by StarBase2.0. The target association among miR-873-5p and MALAT1 or ROCK1 was confirmed using the luciferase assay. The relationship between ROCK1 and MALAT1 or miR-873-5p expression in OS was investigated using Spearman's correlation analysis. MALAT1 was up-regulated and was linked to a lower survival rate of patients in OS. The malignant behaviors of cells were inhibited by down-regulated MALAT1 in vitro. Dual-luciferase gene experiments confirmed the presence of MALAT1/miR-873-5p/ROCK1 axis. The up-regulated miR-873-5p blocked the promoted effects of MALAT1 on cell behaviors. Over-expressed MALAT1 promoted the malignant behaviors of cells by miR-873-5p/ROCK1 axis in OS.

Genome-wide identification of long intergenic non-coding RNAs for Ralstonia solanacearum resistance in tomato (Solanum lycopersicum)

There is growing evidences indicating that long intergenic ncRNAs (lincRNAs) play key roles in plant development and stress responses. To research tomato lincRNA functions during the interaction between tomato and Ralstonia solanacearum, RNA-seq data of tomato plants inoculated with R. solanacearum was analyzed. In this study, 315 possible lincRNAs were identified from RNA-seq data. Then 23 differentially expressed lincRNAs between tomato plants inoculated with R. solanacearum and control were identified and a total of 171 possible target genes for these differentially expressed lincRNAs were predicted. Through GO and KEGG analysis, we found that lincRNA might be involved in jasmonic acid and ethylene signaling pathways to respond to tomato bacterial wilt infection. Furthermore, lincRNA may also be involved in regulating the expression of AGO protein. Subsequently, analysis of expression patterns between differentially expressed lincRNAs and adjacent mRNAs by qRT-PCR revealed that part of lincRNAs and their possible target genes exhibited positive correlation. Taken together, these results suggest that lincRNAs play potential roles in tomato against R. solanacearum infection and will provide fundamental information about the lincRNA-based plant defense mechanisms.

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone tumors in children and adolescents. Large numbers of studies have focused on the long non-coding RNA (lncRNA) that plays essential roles in the progression of osteosarcoma. Nevertheless, the functions and underlying mechanisms of LncRNA NDRG1 in osteosarcoma remain unknown.

METHODS

Differentially expressed lncRNAs between osteosarcoma and adjacent normal tissues were identified through RNA sequencing. The role of LncRNA NDRG1 in osteosarcoma proliferation and metastasis were investigated through in vitro and in vivo functional experiments. The interaction between LncRNA NDRG1 and miR-96-5p was verified through bioinformatic analysis and luciferase reporter assay. Regulation relationship between LncRNA NDRG1 and miR-96-5p was further evaluated by the rescue experiments. Additionally, the changes in the expression of epithelial-mesenchymal transition (EMT) and the PI3K/AKT pathway were verified by Western blot.

RESULTS

LncRNA NDRG1 was up-regulated in osteosarcoma cell lines and tissues and the expression of LncRNA NDRG1 was correlated with the overall survival of osteosarcoma patients. Functional experiments exhibited that LncRNA NDRG1 aggravated osteosarcoma proliferation and migration in vitro; meanwhile, animals experiments showed that LncRNA NDRG1 promoted osteosarcoma growth and metastasis in vivo. Mechanistically, LncRNA NDRG1 was found to aggravate osteosarcoma progression and regulate the PI3K/AKT pathway by sponging miR-96-5p.

CONCLUSIONS

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p. Therefore, LncRNA NDRG1 could act as a prognostic marker and a therapeutic target for osteosarcoma in the future.

The Intersection of Non-Coding RNAs Contributes to Forest Trees' Response to Abiotic Stress

Non-coding RNAs (ncRNAs) play essential roles in plants by modulating the expression of genes at the transcriptional or post-transcriptional level. In recent years, ncRNAs have been recognized as crucial regulators for growth and development in forest trees, and ncRNAs that respond to various abiotic stresses are now under intense study. In this review, we summarized recent advances in the understanding of abiotic stress-responsive microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) in forest trees. Furthermore, we analyzed the intersection of miRNAs, and epigenetic modified ncRNAs of forest trees in response to abiotic stress. In particular, the abiotic stress-related lncRNA/circRNA-miRNA-mRNA regulatory network of forest trees was explored.

Inconsistency in the expression pattern of a five-lncRNA signature as a potential diagnostic biomarker for gastric cancer patients in bioinformatics and in vitro

Objectives

Due to diagnosis of gastric cancer in advanced stages as well as its poor prognosis, finding biomarkers is essential. In this study, using the TCGA RNAseq data of gastric cancer patients, we evaluated the diagnostic value of lncRNAs that had differential expression.

Materials and Methods

We evaluated P-value, FDR, and log fold change for whole transcripts. Next, by comparison of the RNAseq gene names with the total known lncRNA names, we identified differential expressed lncRNAs. Following this, specificity and sensitivity for lncRNAs coming from the previous step were calculated. For more confirmation, we predicted target genes and performed GO and KEGG signaling pathway analysis. In the end, we examined reliability and consistency of expression of this signature in three gastric cancer cell lines and one of them in twenty tumors and tumor-adjacent normal tissue samples using qRT-PCR.

Results

Five lncRNAs had proper sensitivity and specificity and had target genes involved in cancer-related signaling pathways; however, they showed different expression patterns in TCGA data and in vitro.

Conclusion

The results of our study demonstrated that the five-lncRNAs PART1, UCA1, DIRC3, HOTAIR, and HOXA11AS require more investigation to be confirmed as diagnostic biomarkers in gastric cancer.

Identification and validation of an epigenetically regulated long noncoding RNA model for breast cancer metabolism and prognosis

Background

Breast cancer (BC) is the leading cause of death among women, and epigenetic alterations that can dysregulate long noncoding RNAs (lncRNAs) are thought to be associated with cancer metabolism, development, and progression. This study investigated the epigenetic regulation of lncRNAs and its relationship with clinical outcomes and treatment responses in BC in order to identify novel and effective targets for BC treatment.

Methods

We comprehensively analysed DNA methylation and transcriptome data for BC and identified epigenetically regulated lncRNAs as potential prognostic biomarkers using machine learning and multivariate Cox regression analysis. Additionally, we applied multivariate Cox regression analysis adjusted for clinical characteristics and treatment responses to identify a set of survival-predictive lncRNAs, which were subsequently used for functional analysis of protein-encoding genes to identify downstream biological pathways.

Results

We identified a set of 1350 potential epigenetically regulated lncRNAs and generated a methylated lncRNA dataset for BC, MylnBrna, comprising 14 lncRNAs from a list of 20 epigenetically regulated lncRNAs significantly associated with tumour survival. MylnBrna stratifies patients into high-risk and low-risk groups with significantly different survival rates. These lncRNAs were found to be closely related to the biological pathways of amino acid metabolism and tumour metabolism, revealing a potential tumour-regulation function.

Conclusion

This study established a potential prognostic biomarker model (MylnBrna) for BC survival and offered an insight into the epigenetic regulatory mechanisms of lncRNAs in BC in the context of tumour metabolism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01256-2.

LncR-133a Suppresses Myoblast Differentiation by Sponging miR-133a-3p to Activate the FGFR1/ERK1/2 Signaling Pathway in Goats

Long noncoding RNAs (lncRNAs) are involved in a variety of biological processes and illnesses. While a considerable number of lncRNAs have been discovered in skeletal muscle to far, their role and underlying processes during myogenesis remain mostly unclear. In this study, we described a new functional lncRNA named lncR-133a. Gene overexpression and interference studies in goat skeletal muscle satellite cells (MuSCs) were used to establish its function. The molecular mechanism by which lncR-133a governs muscle differentiation was elucidated primarily using quantitative real-time PCR (qRT-PCR), Western blotting, dual-luciferase activity assays, RNA immunoprecipitation, biotin-labeled probe, and RNA fluorescence in situ hybridization analyses. LncR-133a was found to be substantially expressed in longissimus thoracis et lumborum muscle, and its expression levels changed during MuSC differentiation in goats. We validated that lncR-133a suppresses MuSC differentiation in vitro. Dual-luciferase reporter screening, Argonaute 2 (AGO2) RNA immunoprecipitation assays, biotin-labeled lncR-133a capture, and fluorescence in situ hybridization showed that lncR-133a interacted with miR-133a-3p. Additionally, miR-133a-3p facilitated MuSC differentiation, but lncR-133a reversed this effect. The luciferase reporter assay and functional analyses established that miR-133a-3p directly targets fibroblast growth factor receptor 1 (FGFR1). Moreover, lncR-133a directly reduced miR-133a-3p’s capacity to suppress FGFR1 expression, and positively regulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). In summary, our results suggested that lncR-133a suppresses goat muscle differentiation by targeting miR-133a-3p and activating FGFR1/ERK1/2 signaling pathway.

LncRNA HCG11 Facilitates Nasopharyngeal Carcinoma Progression Through Regulating miRNA-490-3p/MAP3K9 Axis

Purpose

Long noncoding RNAs (LncRNAs) play complex but important roles in the progression of various tumors. This study aimed to elucidate the functional mechanisms of the HLA complex group 11 (HCG11) in nasopharyngeal carcinoma (NPC).

Patients and Methods

HCG11 levels in NPC specimens were determined by fluorescence in situ hybridization (FISH) and qPCR. Proliferation, apoptosis, and metastasis of NPC cells were determined using CCK8, colony formation, annexin V-PI, and transwell assays. A murine tumor xenograft model was used to investigate the regulatory function of HCG11 in NPC in vivo, and immunohistochemical staining was used to determine the Ki-67 level in tumors. The target relationships between HCG11, microRNA miR-490-3p, and MAPK kinase kinase 9 (MAP3K9) were detected using bioinformatics, qPCR, western blotting, and luciferase reporter assays.

Results

HCG11 was highly expressed in NPC tissues and was positively associated with tumor stage, lymphatic metastasis, and poor prognosis. Functionally, HCG11 knockdown inhibited proliferation and migration and induced apoptosis of NPC cells. Mechanistically, miR-490-3p is a direct target of HCG11, oncogenic functions of HCG11 in NPC cell proliferation and migration can be partially reversed by the miR-490-3p inhibitor. HCG11 significantly increased mitogen-activated protein kinase MAPK kinase 9 (MAP3K9) levels by inhibiting miR-490-3p.

Conclusion

HCG11 facilitates NPC progression via MAP3K9 signaling by sponging miRNA-490-3p, which may contribute to new prognostic markers and promising therapeutic targets.

Genome-wide identification and characterization of Fusarium circinatum-responsive lncRNAs in Pinus radiata

Background

One of the most promising strategies of Pine Pitch Canker (PPC) management is the use of reproductive plant material resistant to the disease. Understanding the complexity of plant transcriptome that underlies the defence to the causal agent Fusarium circinatum, would greatly facilitate the development of an accurate breeding program. Long non-coding RNAs (lncRNAs) are emerging as important transcriptional regulators under biotic stresses in plants. However, to date, characterization of lncRNAs in conifer trees has not been reported. In this study, transcriptomic identification of lncRNAs was carried out using strand-specific paired-end RNA sequencing, from Pinus radiata samples inoculated with F. circinatum at an early stage of infection.

Results

Overall, 13,312 lncRNAs were predicted through a bioinformatics approach, including long intergenic non-coding RNAs (92.3%), antisense lncRNAs (3.3%) and intronic lncRNAs (2.9%). Compared with protein-coding RNAs, pine lncRNAs are shorter, have lower expression, lower GC content and harbour fewer and shorter exons. A total of 164 differentially expressed (DE) lncRNAs were identified in response to F. circinatum infection in the inoculated versus mock-inoculated P. radiata seedlings. The predicted cis-regulated target genes of these pathogen-responsive lncRNAs were related to defence mechanisms such as kinase activity, phytohormone regulation, and cell wall reinforcement. Co-expression network analysis of DE lncRNAs, DE protein-coding RNAs and lncRNA target genes also indicated a potential network regulating pectinesterase activity and cell wall remodelling.

Conclusions

This study presents the first comprehensive genome-wide analysis of P. radiata lncRNAs and provides the basis for future functional characterizations of lncRNAs in relation to pine defence responses against F. circinatum.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08408-9.

Drought tolerance improvement in Solanum lycopersicum: an insight into "OMICS" approaches and genome editing

Solanum lycopersicum (tomato) is an internationally acclaimed vegetable crop that is grown worldwide. However, drought stress is one of the most critical challenges for tomato production, and it is a crucial task for agricultural biotechnology to produce drought-resistant cultivars. Although breeders have done a lot of work on the tomato to boost quality and quantity of production and enhance resistance to biotic and abiotic stresses, conventional tomato breeding approaches have been limited to improving drought tolerance because of the intricacy of drought traits. Many efforts have been made to better understand the mechanisms involved in adaptation and tolerance to drought stress in tomatoes throughout the years. "Omics" techniques, such as genomics, transcriptomics, proteomics, and metabolomics in combination with modern sequencing technologies, have tremendously aided the discovery of drought-responsive genes. In addition, the availability of biotechnological tools, such as plant transformation and the recently developed genome editing system for tomatoes, has opened up wider opportunities for validating the function of drought-responsive genes and the generation of drought-tolerant varieties. This review highlighted the recent progresses for tomatoes improvement against drought stress through "omics" and "multi-omics" technologies including genetic engineering. We have also discussed the roles of non-coding RNAs and genome editing techniques for drought stress tolerance improvement in tomatoes.

Small open reading frames in plant research: from prediction to functional characterization

Gene prediction is a laborious and time-consuming task. The advancement of sequencing technologies and bioinformatics tools, coupled with accelerated rate of ribosome profiling and mass spectrometry development, have made identification of small open reading frames (sORFs) (< 100 codons) in various plant genomes possible. The past 50 years have seen sORFs being isolated from many organisms. However, to date, a comprehensive sORF annotation pipeline is as yet unavailable, hence, addressed in our review. Here, we also provide current information on classification and functions of plant sORFs and their potential applications in crop improvement programs.

lncRsp1, a long noncoding RNA, influences Fgsp1 expression and sexual reproduction in Fusarium graminearum

Long noncoding RNAs (lncRNAs) are crucial regulators of gene expression in many biological processes, but their biological functions remain largely unknown, especially in fungi. Fusarium graminearum is an important pathogen that causes the destructive disease Fusarium head blight (FHB) or head scab disease on wheat and barley. In our previous RNA sequencing (RNA-Seq) study, we discovered that lncRsp1 is an lncRNA that is located +99 bp upstream of a putative sugar transporter gene, Fgsp1, with the same transcription direction. Functional studies revealed that ΔlncRsp1 and ΔFgsp1 were normal in growth and conidiation but had defects in ascospore discharge and virulence on wheat coleoptiles. Moreover, lncRsp1 and Fgsp1 were shown to negatively regulate the expression of several deoxynivalenol (DON) biosynthesis genes, TRI4, TRI5, TRI6, and TRI13, as well as DON production. Further analysis showed that the overexpression of lncRsp1 enhanced the ability of ascospore release and increased the mRNA expression level of the Fgsp1 gene, while lncRsp1-silenced strains reduced ascospore discharge and inhibited Fgsp1 expression during the sexual reproduction stage. In addition, the lncRsp1 complementary strains lncRsp1-LC-1 and lncRsp1-LC-2 restored ascospore discharge to the level of the wild-type strain PH-1. Taken together, our results reveal the distinct and specific functions of lncRsp1 and Fgsp1 in F. graminearum and principally demonstrate that lncRsp1 can affect the release of ascospores by regulating the expression of Fgsp1.

Identification of Long Non-coding RNA Transcripts in Glycyrrhiza uralensis

Background:

Chinese liquorice (Glycyrrhiza uralensis), an important medicinal plant, contains various valuable secondary metabolites. Secondary metabolites biosynthesis is very tightly regulated; therefore, elucidation and manipulation of the biosynthetic pathways are of great interest. Recent studies have shown that lncRNAs play important regulatory roles in many biological processes, thus identification and modification of their expression is essential to metabolic pathways for biosynthesis of secondary metabolites.

Objectives:

In this study we attempted to identify non-coding RNA transcripts (lncRNAs) that may act as important regulators of diverse biological processes, including stress responses and developmental programs in Glycyrrhiza uralensis.

Materials and Methods:

Identification of potential lncRNAs in Chinese liquorice was performed using a bioinformatics pipeline from the available EST dataset of G. uralensis.

Results:

Bioinformatics analysis revealed that 1365 identical sequences in the range of 200 to 1286 base pair are putative lncRNAs. Only less than one percent of the predicted lncRNAs display sequence conservation with lncRNAs from other species. Moreover, 13 lncRNAs were detected as the potential precursors of 16 miRNAs. From this analysis, we also detected possible target genes of 16 known miRNA genes. The majority of the predicted miRNA target genes have important role in response to plant disease and a couple of them contribute to signalling and metabolic pathways.

Conclusion:

This study demonstrates the existence of lncRNAs in G. uralensis which has not been found before and provides valuable resources for further understanding and characterizing of lncRNAs and also a basis for additional investigation to reveal specific roles of lncRNAs in various biological processes and particularly in response to plant diseases.

Targeting the Expression of Long Noncoding RNAs in Murine Satellite Cells from Single Myofibers

LncRNAs have been recently implicated in the epigenetic control of muscle differentiation and their functional characterization has traditionally relied upon in vitro models of myogenic differentiation. However, the use of experimental paradigms to specifically target lncRNAs expression in muscle stem cells (MuSCs), also known as satellite cells, represents an important requisite to interrogate their function in more physiological contexts. Since isolation and culture of single myofibers preserves satellite cells within their physiological niche underneath the surrounding basal lamina, this procedure represents the optimal approach to follow satellite cell dynamics ex-vivo, such as activation from quiescence, expansion of committed progenitors, differentiation, and self-renewal. Here, we detail an optimized protocol to isolate viable single myofibers from the extensor digitorum longus (EDL) skeletal muscle of adult mice and to manipulate the expression of lncRNAs by antisense LNA GapmeRs-mediated knock-down (KD). Furthermore, we describe a method of EdU incorporation that, coupled to lncRNA KD and subsequent immunofluorescence analysis of proliferating, differentiating, and satellite cell-specific markers, permits the inference of lncRNAs function on muscle stem cells dynamics. Graphic abstract: Graphical representation of the single myofiber isolation method. Experimental workflow showing the main steps of the protocol procedure: EDL muscle harvesting from the mouse hindlimb; EDL digestion into single myofibers; transfection with antisense oligos and culture for 96h; immunofluorescence protocol and image outcome.

LncRNA-URHC Functions as ceRNA to Regulate DNAJB9 Expression by Competitively Binding to miR-5007-3p in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is often diagnosed at a late stage, when the prognosis is poor. The regulation of long noncoding RNAs (lncRNAs) plays a crucial role in HCC. However, the precise regulatory mechanisms of lncRNA signaling in HCC remain largely unknown. Our study aims to investigate the underlying mechanisms of lncRNA (upregulated in hepatocellular carcinoma) URHC in HCC.

OBJECTIVE

To study the in vivo and in vitro localization and biological effects of URHC on liver cancer cells. Through bioinformatics analysis, dual-luciferase reporter gene analysis and rescue experiments revealed the possible mechanism of URHC.

METHODS

RT-qPCR, fluorescence in situ hybridization (FISH) staining, EdU, colony formation, and tumor xenograft experiments were used to identify localized and biological effects of URHC on HCC cells in vitro and in vivo. The bioinformatics analysis, dual-luciferase reporter assay, and rescue experiments revealed the potential mechanism of URHC.

RESULTS

URHC silencing may inhibit the HCC cells' proliferation in vitro and in vivo. We found that URHC was mainly localized in the cytoplasm. The expression of miR-5007-3p was negatively regulated by URHC. And miR-5007-3p could reverse the effect of URHC in HCC cells. The expression of DNAJB9 was negatively regulated by miR-5007-3p but positively regulated by URHC. These suggestive of lncRNA-URHC positively regulated the level of DNAJB9 by sponging miR-5007-3p.

CONCLUSION

Together, our study elucidated the role of URHC as a miRNA sponge in HCC and shed new light on lncRNA-directed diagnostics and therapeutics in HCC.

DCP1A is an unfavorable prognostic-related enhancer RNA in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) are associated with occurrence and development of tumors. Enhancer RNA (eRNA) is a special type of lncRNAs produced from transcription of enhancer elements. The function of eRNAs in tumors have elicited significant attention recently. However, the clinical significance and role of eRNAs in hepatocellular carcinoma (HCC) has not been fully explored. The current study sought to explore the expression level and prognostic value of key eRNAs in HCC. Bioinformatics analyses were used to explore expression levels of key prognostic eRNAs in HCC and their correlation with target genes. A total of 1580 enhancer RNAs (eRNAs) and 1791 target genes were initially retrieved from TCGA-LIHC gene expression database. Further analysis through survival and correlation analysis led to identification of 12 eRNAs and 13 target genes. The findings showed that DCP1A was the most prognosis-related eRNA. This eRNA showed the highest correlation with the target gene, PRKCD. Analysis showed that poor overall survival (OS) in HCC patients was correlated with high expression level of DCP1A (eRNA) and PRKCD (target gene). The up-regulation of DCP1A was associated with advanced tumor stage, larger tumor size and higher histological grade. The results of pan-cancer analysis showed that the expression of DCP1A was differentially expressed in 13 other types of tumor tissues and their corresponding normal tissues. This eRNA was highly expressed in digestive system tumors. Functional analysis showed that high expression level of DCP1A was implicated in multiple tumor-related signaling pathways. The findings of the current study indicated DCP1A is a novel biomarker that can be used as a potential therapeutic target for HCC patients.

Single-Nucleotide Polymorphism LncRNA AC008392.1/rs7248320 in CARD8 is Associated with Kawasaki Disease Susceptibility in the Han Chinese Population

Background

Kawasaki disease (KD) is a multisystem vasculitis in infants and young children and involved in the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome activation. Genetic factors may increase the risk of KD. To assess the association between rs7248320 in long noncoding RNA (lncRNA) AC008392.1 located in the upstream region of CARD8 and the risk of KD, a case–control study was conducted in the Han Chinese population.

Methods

This study genotyped the polymorphism rs7248320 in the lncRNA AC008392.1 gene using the TaqMan real-time polymerase chain reaction assay. The genetic contribution of rs7248320 was evaluated using odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis. The association between rs7248320 and KD susceptibility was analyzed by performing a hospital-based case–control study including 559 KD patients and 1055 non-KD controls.

Results

In this study, a significant relationship between rs7248320 and KD risk was observed in the genotype/allele frequency distribution. The rs7248320 polymorphism was associated with a significantly decreased risk of KD after adjustment for age and sex (AG vs AA: adjusted OR = 0.80, 95% CI: 0.64–0.99, P = 0.0421; GG vs AA: adjusted OR = 0.71, 95% CI: 0.51–1.00, P = 0.0492; AG/GG vs AA: adjusted OR = 0.78, 95% CI: 0.63–0.96, P = 0.0186). Moreover, the rs7248320 G allele also exhibited a decreased risk for KD (adjusted OR = 0.83, 95% CI: 0.72–0.97, P = 0.0193) compared with the A allele. In the stratification analysis, compared to the rs7248320 AA genotype, AG/GG genotypes were more protective for males (OR = 0.71, 95% CI: 0.55–0.93, P = 0.0122).

Conclusion

This study suggests for the first time that the lncRNA AC008392.1 rs7248320 polymorphism may be involved in KD susceptibility in the Han Chinese population.

Development and validation of a set of novel and robust 4-lncRNA-based nomogram predicting prostate cancer survival by bioinformatics analysis

Background and objective

Accumulating evidence shows that long noncoding RNAs (lncRNAs) possess great potential in the diagnosis and prognosis of prostate cancer (PCa). Therefore, this study aimed to construct an lncRNA-based signature to more accurately predict the prognosis of different PCa patients, so as to improve patient management and prognosis.

Methods

Through univariate and multivariate Cox regression analysis, this study constructed a 4 lncRNAs-based prognosis nomogram for the classification and prediction of survival risk in patients with PCa based on TCGA data. Then we used the data of TCGA and ICGC to verify the performance of our prediction model. The receiver operating characteristic curve was plotted for detecting and validating our prediction model sensitivity and specificity. In addition, Cox regression analysis was conducted to examine whether the signature’s prediction ability was independent of additional clinicopathological variables. Possible biological functions for those prognostic lncRNAs were predicted on those 4 protein-coding genes (PCGs) related to lncRNAs.

Results

Four lncRNAs (HOXB-AS3, YEATS2-AS1, LINC01679, PRRT3-AS1) were extracted after COX regression analysis for classifying patients into high and low-risk groups by different OS rates. As suggested by ROC analysis, our proposed model showed high sensitivity and specificity. Independent prognostic capability of the model from other clinicopathological factors was indicated through further analysis. Based on functional enrichment, those action sites for prognostic lncRNAs were mostly located in the extracellular matrix and cell membrane, and their functions are mainly associated with the adhesion, activation and transport of the components across the extracellular matrix or cell membrane.

Conclusion

Our current study successfully identifies a novel candidate, which can provide more convincing evidence for prognosis in addition to the traditional clinicopathological indicators to predict the PCa survival, and laying the foundation for offering potentially novel therapeutic treatment. Additionally, this study sheds more lights on the PCa-related molecular mechanisms.

Biomarkers (mRNAs and Non-Coding RNAs) for the Diagnosis and Prognosis of Colorectal Cancer - From the Body Fluid to Tissue Level

In recent years, the diagnosis and treatment of colorectal cancer (CRC) have been continuously improved, but the mortality rate continues to be high, especially in advanced patients. CRC patients usually have no obvious symptoms in the early stage and are already in the advanced stage when they are diagnosed. The 5-year survival rate is only 10%. The blood markers currently used to screen for CRC, such as carcinoembryonic antigen and carbohydrate antigen 19-9, have low sensitivity and specificity, whereas other methods are invasive or too expensive. As a result, recent research has shifted to the development of minimally invasive or noninvasive biomarkers in the form of body fluid biopsies. Non-coding RNA molecules are composed of microRNAs, long non-coding RNAs, small nucleolar RNAs, and circular RNAs, which have important roles in the occurrence and development of diseases and can be utilized for the early diagnosis and prognosis of tumors. In this review, we focus on the latest findings of mRNA-ncRNA as biomarkers for the diagnosis and prognosis of CRC, from fluid to tissue level.

Physiological Characteristic Changes and Full-Length Transcriptome of Rose (Rosa chinensis) Roots and Leaves in Response to Drought Stress

Rose (Rosa chinensis) is the most important ornamental crops worldwide. However, the physiological and molecular mechanism of rose under drought stress remains elusive. In this study, we analyzed the changes of photosynthetic and phytohormone levels in the leaves and roots of rose seedlings grown under control (no drought), mild drought (MD) and severe drought stress. The total chlorophyll content and water use efficiency were significantly enhanced under MD in rose leaves. In addition, the concentration of ABA was higher in the leaves compared to the roots, whereas the roots accumulated more IAA, methylindole-3-acetic acid and indole-3-propionic acid. We also constructed the first full-length transcriptome for rose, and identified 96,201,862 full-length reads of average length 1,149 bp that included 65,789 novel transcripts. A total of 3,657 and 4,341 differentially expressed genes (DEGs) were identified in rose leaves and roots respectively. KEGG pathway analysis showed enrichment of plant hormone, signal transduction and photosynthesis are among the DEGs. 42,544 alternatively spliced isoforms were also identified, and alternative 3' splice site was the major alternative splicing (AS) event among the DEGs. Variations in the AS patterns of three genes between leaves and roots indicated the possibility of tissue-specific posttranscriptional regulation in response to drought stress. Furthermore, 2,410 novel long non-coding RNAs were detected that may participate in regulating the drought-induced DEGs. Our findings identified previously unknown splice sites and new genes in the rose transcriptome, and elucidated the drought stress-responsive genes as well as their intricate regulatory networks.

Transcriptome analysis and association mapping reveal the genetic regulatory network response to cadmium stress in Populus tomentosa

Long non-coding RNAs (lncRNAs) play essential roles in plant abiotic stress responses, but the response of lncRNA-mediated genetic networks to cadmium (Cd) treatment remain elusive in trees, the promising candidates for phytoremediation of Cd contamination. We identified 172 Cd-responsive lncRNAs and 295 differentially expressed target genes in the leaves of Cd-treated Populus tomentosa. Functional annotation revealed that these lncRNAs were involved in various processes, including photosynthesis, hormone regulation, and phenylalanine metabolism. Association studies identified 78 significant associations, representing 14 Cd-responsive lncRNAs and 28 target genes for photosynthetic and leaf physiological traits. Epistasis uncovered 83 pairwise interactions among these traits, revealing Cd-responsive lncRNA-mediated genetic networks for photosynthesis and leaf physiology in P. tomentosa. We focused on the roles of two Cd-responsive lncRNA-gene pairs, MSTRG.22608.1-PtoMYB73 and MSTRG.5634.1-PtoMYB27, in Cd tolerance of Populus, and detected insertions/deletions within lncRNAs as polymorphisms driving target gene expression. Genotype analysis of lncRNAs and heterologous overexpression of PtoMYB73 and PtoMYB27 in Arabidopsis indicated their effects on enhancing Cd tolerance, photosynthetic rate, and leaf growth, and the potential interaction mechanisms of PtoMYB73 with abiotic stresses. Our study identifies the genetic basis for the response of Populus to Cd treatment, facilitating genetic improvement of Cd tolerance in trees.

Long Non-Coding RNAs, the Dark Matter: An Emerging Regulatory Component in Plants

Long non-coding RNAs (lncRNAs) are pervasive transcripts of longer than 200 nucleotides and indiscernible coding potential. lncRNAs are implicated as key regulatory molecules in various fundamental biological processes at transcriptional, post-transcriptional, and epigenetic levels. Advances in computational and experimental approaches have identified numerous lncRNAs in plants. lncRNAs have been found to act as prime mediators in plant growth, development, and tolerance to stresses. This review summarizes the current research status of lncRNAs in planta, their classification based on genomic context, their mechanism of action, and specific bioinformatics tools and resources for their identification and characterization. Our overarching goal is to summarize recent progress on understanding the regulatory role of lncRNAs in plant developmental processes such as flowering time, reproductive growth, and abiotic stresses. We also review the role of lncRNA in nutrient stress and the ability to improve biotic stress tolerance in plants. Given the pivotal role of lncRNAs in various biological processes, their functional characterization in agriculturally essential crop plants is crucial for bridging the gap between phenotype and genotype.

LncRNA MALAT1 Aggravates the Progression of Non-Small Cell Lung Cancer by Stimulating the Expression of COMMD8 via Targeting miR-613

Background

Non-small cell lung cancer (NSCLC) is a common malignant tumor in humans. Long non-coding RNA (lncRNA) involved in cancer progression has been reported frequently. The objective of this study was to investigate the role of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and explore a novel mechanism in NSCLC development.

Materials and Methods

The expression of MALAT1, copper metabolism MURR1 domain-containing 8 (COMMD8) and microRNA-613 (miR-613) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of COMMD8, Cyclin D1, Ki67, B cell lymphoma/leukemia-2 (Bcl-2), Bcl-2 associated X protein (Bax), lactate dehydrogenase A (LDHA), CD63 and CD81 were determined by Western blot. Cell proliferation, the number of colonies and cell apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation and flow cytometry assays, respectively. Glycolysis was distinguished based on glucose consumption, lactate production and LDHA activity. The role of MALAT1 in vivo was verified by animal experiments. The relationship between miR-613 and MALAT1 or COMMD8 was predicted by the bioinformatics tool starbase and verified by dual-luciferase reporter assay. The exosomes were isolated using the corresponding kit and identified by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA).

Results

MALAT1 and COMMD8 were aberrantly upregulated in NSCLC tissues and cells. MALAT1 or COMMD8 knockdown blocked cell proliferation, colony formation and glycolysis but accelerated cell apoptosis in vitro. Besides, MALAT1 knockdown reduced tumor growth in vivo. We found that miR-613 was a target of MALAT1, and miR-613 could bind to the 3ʹ untranslated region (3ʹUTR) of COMMD8. MALAT1 regulated the expression of COMMD8 by absorbing miR-613. Moreover, the extracellular MALAT1 was transmitted by wrapping into exosomes.

Conclusion

MALAT1 promoted malignant activities of NSCLC cells through targeting miR-613/COMMD8 axis, and exosome-mediated transfer of NSCLC might be a novel approach for NSCLC treatment.

Long Intergenic Non-Coding RNA LINC00922 Aggravates the Malignant Phenotype of Breast Cancer by Regulating the microRNA-424-5p/BDNF Axis

PURPOSE

Long intergenic non-coding RNA 922 (LINC00922) plays a critical role in the progression of lung cancer. In this study, we aimed to quantify LINC00922 expression in breast cancer and determine its influence on the malignant behavior of breast cancer cells in vitro and in vivo. We also investigated the mechanism by which LINC00922 affects the progression of breast cancer.

MATERIALS AND METHODS

Reverse transcription-quantitative polymerase chain reaction was performed to quantify LINC00922 expression in breast cancer tissues and cell lines. The cell counting kit-8 assay, flow cytometry, Transwell migration and invasion assays, and tumor model assays were performed to determine the effects of LINC00922 deficiency on breast cancer cell proliferation, apoptosis, migration and invasion in vitro, and tumor growth in vivo, respectively. Furthermore, bioinformatics analysis was performed to predict the potential target microRNA of LINC00922. The prediction was further evaluated using luciferase reporter and RNA immunoprecipitation assays.

RESULTS

LINC00922 was clearly overexpressed in breast cancer tissues and cell lines. LINC00922 depletion restricted breast cancer cell proliferation, migration, and invasion but induced cell apoptosis in vitro. Additionally, its knockdown evidently repressed tumor growth of breast cancer cells in vivo. Mechanistically, LINC00922 was demonstrated to serve as a molecular sponge for miR-424-5p in breast cancer cells. Furthermore, brain-derived neurotrophic factor (BDNF) was verified as a direct target of miR-424-5p in breast cancer cells, and BDNF expression was found to be positively regulated by LINC00922 through sponging miR-425-5p. Rescue experiments further revealed that the influences on breast cancer cell proliferation, apoptosis, migration, and invasion induced by LINC00922 silencing were abrogated by increasing the output of the miR-424-5p/BDNF axis.

CONCLUSION

The LINC00922/miR-424-5p/BDNF pathway is implicated in the acceleration of the malignant behavior of breast cancer cells. These findings suggest that this pathway is a promising novel molecular target in breast cancer therapy.

LncRNA BC200 Promotes Esophageal Squamous Cell Cancer Migration and Invasion and Can Regulate ATF4 Expression

Background: The main reason for esophageal squamous cell carcinoma (ESCC) treatment failure is metastasis. Little is known about the mechanisms involved in the metastasis of ESCC, and there is a lack of effective therapeutic targets. In our previous study, we found that patients with high levels of BC200 tended to have poor prognoses.

Methods: First, we applied qRT-PCR to detect the expression level of BC200 in normal esophageal squamous epithelial cells and ESCC cells with different degrees of differentiation ability. Then, we changed BC200 expression by transfecting constructed lentiviruses that included BC200 shRNA (LV-BC200-shRNA, KD), negative control (CON053, NC), or BC200 gene (LV-BC200, BC200) to create BC200-deficient cell models in KYSE410 and KYSE70 cells and BC200 overexpression cell models in EC9706 cells and verified the transfection effect by qRT-PCR. Then, we examined cell migration by wound healing assay, invasion by Transwell assay, and proliferation by MTT assay and examined the metastasis ability in a xenograft mouse model. Gene expression profiling was performed to screen a panel of mRNAs following inhibition of BC200 expression. We then used ingenuity pathway analysis (IPA) to analyze the functions of the changed molecules and their interactions. The results from the microarray were validated by qRT-PCR and Western blotting.

Results: In this study, we found that the expression of BC200 in poorly differentiated cell lines was significantly higher than that in well-differentiated cell lines. BC200 can significantly promote the migration and invasion but not the proliferation ability of ESCC cells in vitro and BC200 shRNA can significantly suppress tumor metastasis in vivo. Our genome-wide expression profile chip showed 406 differentially expressed genes, with 91 upregulated genes and 315 downregulated genes. The upstream regulator analysis showed that ATF4 was predicted to be strongly inhibited and 21 genes were consistently inhibited by this gene. Our qRT-PCR and Western blotting data also identified the reduced expression of ATF4 and some selected downstream genes, such as SNAIL2, GADD45A, and PSAT1, as a consequence of downregulating BC200 expression in ESCC.

Conclusion: Our data showed that BC200 promoted the metastasis of ESCC cells and could regulate the expression of ATF4 and its downstream genes.

Discovery, identification, and functional characterization of long noncoding RNAs in Arachis hypogaea L

BACKGROUND

Long noncoding RNAs (lncRNAs), which are typically > 200 nt in length, are involved in numerous biological processes. Studies on lncRNAs in the cultivated peanut (Arachis hypogaea L.) largely remain unknown.

RESULTS

A genome-wide scan of the peanut (Arachis hypogaea L.) transcriptome identified 1442 lncRNAs, which were encoded by loci distributed over every chromosome. Long intergenic noncoding RNAs accounted for 85.58% of these lncRNAs. Additionally, 189 lncRNAs were differentially abundant in the root, leaf, or seed. Generally, lncRNAs showed lower expression levels, tighter tissue-specific expression, and less splicing than mRNAs. Approximately 44.17% of the lncRNAs with an exon/intron structure were alternatively spliced; this rate was slightly lower than the splicing rate of mRNA. Transcription at the start site event was the alternative splicing (AS) event with the highest frequency (28.05%) in peanut lncRNAs, whereas the occurrence rate (30.19%) of intron retention event was the highest in mRNAs. AS changed the target gene profiles of lncRNAs and increased the diversity and flexibility of lncRNAs, which may be important for lncRNAs to execute their functions. Additionally, a substantial number of the peanut AS isoforms generated from protein-encoding genes appeared to be noncoding because they were truncated transcripts; such isoforms can be legitimately regarded as a class of lncRNAs. The predicted target genes of the lncRNAs were involved in a wide range of biological processes. Furthermore, expression pattern of several selected lncRNAs and their target genes were examined under salt stress, results showed that all of them could respond to salt stress in different manners.

CONCLUSIONS

This study provided a resource of candidate lncRNAs and expression patterns across tissues, and whether these lncRNAs are functional will be further investigated in our subsequent experiments.

Molecular mechanisms underlying actions of certain long noncoding RNAs in Alzheimer's disease

Long non-coding RNAs (lncRNAs) are a group of non-protein coding RNAs that have more than 200 nucleotides. LncRNAs play an important role in the regulation of protein-coding genes at the transcriptional and post-transcriptional levels. They are found in most organs, with a high prevalence in the central nervous system. Accumulating data suggests that lncRNAs are involved in various neurodegenerative disorders, including the onset and progression of Alzheimer's disease (AD). Recent insights suggest lncRNAs, such as BACE1-AS, 51A, 17A, NDM29 and AS-UCHL1, are dysregulated in AD tissues. Furthermore, there are ongoing efforts to explore the clinical usability of lncRNAs as biomarkers in the disease. In this review, we explore the mechanisms by which aberrant expressions of the most studied lncRNAs contribute to the neuropathologies associated with AD, including amyloid β plaques and neurofibrillary tangles. Understanding the molecular mechanisms of lncRNAs in patients with AD will reveal novel diagnosis strategies and more effective therapeutic targets.

Identification and Comparative Analysis of Long Non-Coding RNA in the Skeletal Muscle of Two Dezhou Donkey Strains

Long non-coding RNA (lncRNA) has been extensively studied in many livestock. However, compared with other livestock breeds, there is less research regarding donkey lncRNA function. It has been reported that lncRNA plays an important role in the timing control of development, aging, and death of livestock. Therefore, the study of donkey skeletal muscle lncRNA is of great significance for exploring donkey meat production performance. In this study, RNA-Seq was used to perform high-throughput sequencing of skeletal muscle (longissimus dorsi and gluteus) of two Dezhou donkey strains (SanFen and WuTou). The differentially expressed lncRNAs were screened between different strains and tissues. Then candidate genes for conjoint analysis were screened based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Finally, the accuracy of the sequencing data was verified by real-time quantitative polymerase chain reaction (RT-qPCR). Herein, we identified 3869 novel lncRNAs and 73 differentially expressed lncRNAs. Through the comparison between groups, the specific expression of lncRNAs were found in different strains and muscle tissues. Importantly, we constructed the lncRNA-miRNA-mRNA interaction network and found three important candidate lncRNAs (MSTRG.9787.1, MSTRG.3144.1, and MSTRG.9886.1) and four candidate genes (ACTN1, CDON, FMOD, and BMPR1B). Analysis of the KEGG pathway indicates that the TGF-β signaling pathway plays a pivotal role in the growth and development of skeletal muscle in Dezhou donkey strains.

The Prognostic Signature and Potential Target Genes of Six Long Non-coding RNA in Laryngeal Squamous Cell Carcinoma

Studies have shown that long non-coding RNA (lncRNA) may act as the carcinogenic factor or tumor suppressor of laryngeal squamous cell carcinoma (LSCC). This study aims to identify the prognostic value and potential target protein-coding genes (PCGs) of lncRNAs in LSCC. The LSCC datasets were collected from The Cancer Genome Atlas (TCGA). Statistical and bioinformatic methods were used to establish and evaluate the prognostic model, identify the correlation between lncRNAs and clinical characteristics, and screen for PCGs co-expressed with lncRNAs. Weighted gene co-expression network analysis (WGCNA) identified PCG modules associated with clinical characteristics. The expression of lncRNAs and PCGs was analyzed using our LSCC patients by RT-qPCR. LINC02154, LINC00528, SPRY4-AS1, TTTY14, LNCSRLR, and KLHL7-DT were selected to establish the prognostic model. The overall survival (OS) of low-risk patients forecasted by the model was significantly better than high-risk patients. Receiver operating characteristic (ROC) curve and concordance index (C-index) validated the accuracy of the prognostic model. Chi-square test showed that six lncRNAs were associated with one of the clinical characteristics, i.e., gender, clinical stage, T and N stage, respectively. WGCNA identified PCG modules associated with gender, clinical stage, T and N stage. We took the intersection of the PCG modules of WGCNA, the differentially expressed PCGs between LSCC and normal samples, and the PCGs co-expressed with six lncRNAs. The intersection PCGs survival analysis showed that four PCGs, i.e., STC2, TSPAN9, SMS, and TCEA3 affected the OS of LSCC. More importantly, the differential expression of six lncRNAs and four PCGs between LSCC and normal samples was verified by our LSCC patients. In conclusion, we successfully established a prognostic model based on six-lncRNA RiskScore and initially screened the potential target PCGs of six lncRNAs for further basic and clinical research.

Potential Roles of Long Noncoding RNAs as Therapeutic Targets in Renal Fibrosis

Many studies have made clear that most of the genome is transcribed into noncoding RNAs, including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), both of which can affect different cell features. LncRNAs are long heterogeneous RNAs that regulate gene expression and a variety of signaling pathways involved in cellular homeostasis and development. Several studies have demonstrated that lncRNA is an important class of regulatory molecule that can be targeted to change cellular physiology and function. The expression or dysfunction of lncRNAs is closely related to various hereditary, autoimmune, and metabolic diseases, and tumors. Specifically, recent work has shown that lncRNAs have an important role in kidney pathogenesis. The effective roles of lncRNAs have been recognized in renal ischemia, injury, inflammation, fibrosis, glomerular diseases, renal transplantation, and renal-cell carcinoma. The present review focuses on the emerging role and function of lncRNAs in the pathogenesis of kidney inflammation and fibrosis as novel essential regulators. Although lncRNAs are important players in the initiation and progression of many pathological processes, their role in renal fibrosis remains unclear. This review summarizes the current understanding of lncRNAs in the pathogenesis of kidney fibrosis and elucidates the potential role of these novel regulatory molecules as therapeutic targets for the clinical treatment of kidney inflammation and fibrosis.

Long Noncoding RNA SNHG7 Activates Wnt/β-Catenin Signaling Pathway in Cervical Cancer Cells by Epigenetically Silencing DKK1

Background: Cervical cancer (CC) ranks fourth in cancers that resulted in death among women, accumulating the attention of researchers. It has been ascertained that long noncoding RNAs (lncRNAs) are crucial players in the pathological processes of a host of cancers. And, SNHG7 has been reported to enhance the occurrence of various cancers; however, its function in CC sustains obscure. Aim of the Study: This study explored the function of SNHG7 in CC and further investigates the specific molecular mechanism of SNHG7 in regulating CC. Methods: The levels of SNHG7 in CC cells were reflected by quantitative real-time polymerase chain reaction. The functions of SNHG7 on CC tumorigenesis were explored by colony formation, CCK-8 (Cell Counting Kit-8), EdU (ethynyl deoxyuridine), and Western blot assays. The influences of SNHG7 depletion on the binding of EZH2 to DKK1 promoter and H3K27me3 occupancy in DKK1 promoter were studied by chromatin immunoprecipitation assay. Results: SNHG7 was conspicuously higher expressed in CC cells. Knockdown of SNHG7 was detected to ameliorate the malignant behaviors of CC cells. Importantly, the contribution of SNHG7 to CC development was relied on activated Wnt pathway through DDK1-mediated manner. Furthermore, it was confirmed that SNHG7 silencing weakened the binding of EZH2 to DKK1 promoter as well as the occupancy of H3K27me3 in DKK1 promoter. Conclusions: SNHG7 epigenetically silences DKK1 to exacerbate the malignancy of CC via Wnt/β-catenin signaling pathway.

Genome-wide analysis of the transcriptional response to drought stress in root and leaf of common bean

Genes related to the response to drought stress in leaf and root tissue of drought-susceptible (DS) and tolerant (DT) genotypes were characterized by RNA-Seq. In total, 54,750 transcripts, representative of 28,590 genes, were identified; of these, 1,648 were of high-fidelity (merge of 12 libraries) and described for the first time in the Andean germplasm. From the 1,239 differentially expressed genes (DEGs), 458 were identified in DT, with a predominance of genes in categories of oxidative stress, response to stimulus and kinase activity. Most genes related to oxidation-reduction terms in roots were early triggered in DT (T75) compared to DS (T150) suggestive of a mechanism of tolerance by reducing the damage from ROS. Among the KEGG enriched by DEGs up-regulated in DT leaves, two related to the formation of Sulfur-containing compounds, which are known for their involvement in tolerance to abiotic stresses, were common to all treatments. Through qPCR, 88.64% of the DEGs were validated. A total of 151,283 variants were identified and functional effects estimated for 85,780. The raw data files were submitted to the NCBI database. A transcriptome map revealed new genes and isoforms under drought. These results supports a better understanding of the drought tolerance mechanisms in beans.

Identification of tissue-specific and cold-responsive lncRNAs in Medicago truncatula by high-throughput RNA sequencing

BACKGROUND

Long non-coding RNAs (lncRNAs) play important roles in the regulation of plant responses to environmental stress by acting as essential regulators of gene expression. However, whether and how lncRNAs are involved in cold acclimation-dependent freezing tolerance in plants remains largely unknown. Medicago truncatula is a prominent model for studies of legume genomics, and distinguished by its cold-acclimation characteristics. To determine the roles of lncRNAs in plant cold stress response, we conducted genome-wide high-throughput sequencing in the legume model plant M. truncatula.

RESULTS

RNA-seq data were generated from twelve samples for the four treatments, i.e., non-cold treated leaves and roots, cold-treated leaves and roots of M. truncatula Jemalong A17 seedlings. A total of 1204 million raw reads were generated. Of them, 1150 million filtered reads after quality control (QC) were subjected to downstream analysis. A large number of 24,368 unique lncRNAs were identified from the twelve samples. Among these lncRNAs, 983 and 1288 were responsive to cold treatment in the leaves and roots, respectively. We further found that the intronic-lncRNAs were most sensitive to the cold treatment. The cold-responsive lncRNAs were unevenly distributed across the eight chromosomes in M. truncatula seedlings with obvious preferences for locations. Further analyses revealed that the cold-responsive lncRNAs differed between leaves and roots. The putative target genes of the lncRNAs were predicted to mainly involve the processes of protein translation, transport, metabolism and nucleic acid transcription. Furthermore, the networks of a tandem array of CBF/DREB1 genes that were reported to be located in a major freezing tolerance QTL region on chromosome 6 and their related lncRNAs were dissected based on their gene expression and chromosome location.

CONCLUSIONS

We identified a comprehensive set of lncRNAs that were responsive to cold treatment in M. truncatula seedlings, and discovered tissue-specific cold-responsive lncRNAs in leaves and roots. We further dissected potential regulatory networks of CBF Intergenic RNA (MtCIR1) and MtCBFs that play critical roles in response and adaptation of M. truncatula to cold stress.

A novel lncRNA as a positive regulator of carotenoid biosynthesis in Fusarium

The fungi Fusarium oxysporum and Fusarium fujikuroi produce carotenoids, lipophilic terpenoid pigments of biotechnological interest, with xanthophyll neurosporaxanthin as the main end product. Their carotenoid biosynthesis is activated by light and negatively regulated by the RING-finger protein CarS. Global transcriptomic analysis identified in both species a putative 1-kb lncRNA that we call carP, referred to as Fo-carP and Ff-carP in each species, upstream to the gene carS and transcribed from the same DNA strand. Fo-carP and Ff-carP are poorly transcribed, but their RNA levels increase in carS mutants. The deletion of Fo-carP or Ff-carP in the respective species results in albino phenotypes, with strong reductions in mRNA levels of structural genes for carotenoid biosynthesis and higher mRNA content of the carS gene, which could explain the low accumulation of carotenoids. Upon alignment, Fo-carP and Ff-carP show 75-80% identity, with short insertions or deletions resulting in a lack of coincident ORFs. Moreover, none of the ORFs found in their sequences have indications of possible coding functions. We conclude that Fo-carP and Ff-carP are regulatory lncRNAs necessary for the active expression of the carotenoid genes in Fusarium through an unknown molecular mechanism, probably related to the control of carS function or expression.

Role of lncRNAs in stem cell maintenance and differentiation

Embryonic Stem cells are widely studied to elucidate the disease and developmental processes because of their capability to differentiate into cells of any lineage, Pervasive transcription is a distinct feature of all multicellular organisms and genomic elements such as enhancers and bidirectional or unidirectional promoters regulate these processes. Thousands of loci in each species produce a class of transcripts called noncoding RNAs (ncRNAs), that are well known for their influential regulatory roles in multiple biological processes including stem cell pluripotency and differentiation. The number of lncRNA species increases in more complex organisms highlighting the importance of RNA-based control in the evolution of multicellular organisms. Over the past decade, numerous studies have shed light on lncRNA biogenesis and functional significance in the cell and the organism. In this review, we focus primarily on lncRNAs affecting the stem cell state and developmental pathways.

Genome-Wide Identification of Long Noncoding RNAs and Their Responses to Salt Stress in Two Closely Related Poplars

Long noncoding RNAs (lncRNAs) are involved in various biological regulatory processes, but their roles in plants resistance to salt stress remain largely unknown. To systematically explore the characteristics of lncRNAs and their roles in plant salt responses, we conducted strand-specific RNA-sequencing of four tissue types with salt treatments in two closely related poplars (Populus euphratica and Populus alba var. pyramidalis), and a total of 10,646 and 10,531 lncRNAs were identified, respectively. These lncRNAs showed significantly lower values in terms of length, expression, and expression correction than with mRNA. We further found that about 40% and 60% of these identified lncRNAs responded to salt stress with tissue-specific expression patterns across the two poplars. Furthermore, lncRNAs showed weak evolutionary conservation in sequences and exhibited diverse regulatory styles; in particular, tissue- and species-specific responses to salt stress varied greatly in two poplars, for example, 322 lncRNAs were found highly expressed in P. euphratica but not in P. alba var. pyramidalis and 3,425 lncRNAs were identified to be species-specific in P. euphratica in response to salt stress. Moreover, tissue-specific expression of lncRNAs in two poplars were identified with predicted target genes included Aux/IAA, NAC, MYB, involved in regulating plant growth and the plant stress response. Taken together, the systematic analysis of lncRNAs between sister species enhances our understanding of the characteristics of lncRNAs and their roles in plant growth and salt response.

MicroRNA-876 is sponged by long noncoding RNA LINC00707 and directly targets metadherin to inhibit breast cancer malignancy

Background: MicroRNA-876-5p (miR-876) dysregulation contributes to the aggressiveness of various types of human cancer. This study was aimed at measuring miR-876 expression in breast cancer, determining the specific roles of miR-876 in the progression of breast cancer and understanding the corresponding molecular mechanisms.

Materials and methods: miR-876 expression in breast cancer tissues and cell lines was quantified via RT-qPCR. The effect of miR-876 upregulation on the malignant phenotype of breast cancer cells was investigated using CCK-8 assays, flow cytometry, Transwell migration and invasion assays and tumor xenograft experiments. The mechanisms underlying the tumor-suppressive action of miR-876 in breast cancer cells were explored using bioinformatic analysis, luciferase reporter assays, RT-qPCR and Western blot analysis.

Results: miR-876 was found to be underexpressed in breast cancer tissues and cell lines. Decreased miR-876 expression notably correlated with lymphatic invasion metastasis, TNM stage and differentiation grade. Overall survival was lower among patients with breast cancer and low miR-876 expression than in patients with high miR-876 expression. Restoration of miR-876 expression decreased breast cancer cell proliferation, migration and invasion in vitro and restricted tumor growth in vivo as well as increased cell apoptosis. Metadherin (MTDH) was identified as a novel target of miR-876 in breast cancer cells. Furthermore, long intergenic nonprotein-coding RNA 707 (LINC00707) acted as a molecular sponge for miR-876, thereby regulating MTDH expression in breast cancer. Finally, silencing miR-876 expression attenuated the influence of a LINC00707 knockdown on the malignancy of breast cancer cells.

Conclusion: This study, thus, revealed the vital functions of the LINC00707–miR-876–MTDH pathway in breast cancer and provided attractive targets and markers for its treatment.