Long Noncoding RNA TTC39A-AS1 Promotes Breast Cancer Tumorigenicity by Sponging MicroRNA-483-3p and Thereby Upregulating MTA2.

INTRODUCTION: In recent years, the regulatory activities of long noncoding RNAs have received increasing attention as an important research focus. This study aimed to characterize the expression and detailed roles of TTC39A antisense RNA 1 (TTC39A-AS1) in breast cancer (BC), in addition to concentrating on its downstream mechanisms. METHODS: Quantitative RT-PCR was performed to determine the expression levels of TTC39A-AS1, microRNA-483-3p (miR-483-3p), and metastasis-associated gene 2 (MTA2). Further, the detailed functions of TTC39A-AS1 in BC cells were confirmed using the Cell Counting Kit 8 assay, flow cytometric analysis, and Transwell cell migration and invasion assays. The targeting relationship between TTC39A-AS1, miR-483-3p, and MTA2 in BC was predicted via bioinformatics analysis and further confirmed by performing the luciferase reporter assay and RNA immunoprecipitation. RESULTS: TTC39A-AS1 was present in high levels in BC; this result was confirmed in our sample cohort and The Cancer Genome Atlas database. Patients with BC with a high level of TTC39A-AS1 had a shorter overall survival than those with a low level of TTC39A-AS1. Functionally, the absence of TTC39A-AS1 accelerated cell apo-ptosis but retained cell proliferation, migration, and invasion. Mechanistically, TTC39A-AS1 functioned as a competing endogenous RNA in BC by sponging miR-483-3p and thereby indirectly increasing MTA2 expression. Finally, rescue experiments revealed that the tumor-inhibiting actions of TTC39A-AS1 knockdown on the malignant characteristics of BC cells could be reversed by inhibiting miR-483-3p or upregulating MTA2. CONCLUSION: The newly identified TTC39A-AS1/miR-483-3p/MTA2 pathway was revealed to be a critical regulator in the tumorigenicity of BC, possibly offering a novel therapeutic direction for the anticancer treatment of BC.

Overexpression of antisense phosphatase 2C affords cold resistance in hybrid Populus davidiana × Populus bolleana.

BACKGROUND: Overexpression of the abiotic and biotic stress-resistance genes of the plant signaling pathway is well known for its significant role in the regulation of plant growth and enhancement of the productivity of agricultural land under changing climatic conditions. OBJECTIVES: This research aimed to clone Populus davidiana × Populus bolleana PP2C (PdPP2C) gene and analyze its structure and function, and downregulate PdPP2C by overexpression of its antisense PdPP2C (AS-PdPP2C) gene for enhancing cold resistance in transgenic lines of hybrid P. davidiana × P. bolleana. METHODS: PdPP2C was cloned and transformed to identify its function, and its antisense was overexpressed via downregulation to increase the cold resistance in transgenic lines of hybrid P. davidiana × P. bolleana. RESULTS: Antisense inhibition of protein phosphatase 2C accelerates the cold acclimation of Poplar (P. davidiana × P. bolleana) gene in terms of antifreeze. CONCLUSION: PdPP2C was expressed in the roots, stems, and leaves of P. davidiana × P. bolleana, and the expression was higher in the leaves. The expression of PdPP2C was also significantly downregulated at low-temperature (0 °C and 4 °C) stress. The relative conductivity and malondialdehyde content of non-transgenic lines were higher than those of AS-PdPP2C lines after 2 days of cold treatment at - 1 °C. The leaves of the transgenic lines were not wilted and showed no chlorosis compared with those of the non-transgenic lines. The AS-PdPP2C transgenic lines also showed higher freezing resistance than the non-transgenic lines. AS-PdPP2C participated in the regulation of freezing resistance.

Development of multiplexing gene silencing system using conditionally induced polycistronic synthetic antisense RNAs in Escherichia coli.

Although efficient methods of gene silencing have been established in eukaryotes, many different techniques are still used in bacteria due to the lack of a standardized tool. Here, we developed a convenient and efficient method to downregulate the expression of a specific gene using ∼140 nucleotide RNA with a 24-nucleotide antisense region from an arabinose-inducible expression plasmid by taking Escherichia coli lacZ and phoA genes encoding ß-galactosidase and alkaline phosphatase, respectively, as target genes to evaluate the model. We examined the antisense RNA (asRNA) design, including targeting position, uORF stability elements at the 5'-end, and Hfq-binding module at the 3'-end, and inducer amount required to obtain effective experimental conditions for gene silencing. Furthermore, we constructed multiplexed dual-acting asRNA genes in the plasmid, which were transcribed as polycistronic RNA and were able to knockdown multiple target genes simultaneously. We observed the highest inhibition level of 98.6% when lacZ was targeted using the pMKN104 asRNA expression plasmid, containing a five times stronger PBAD -10 promoter sequence with no requirement of the Hfq protein for repression. These features allow the system to be utilized as an asRNA expression platform in many bacteria, besides E. coli, for gene regulation.

Long noncoding RNA KTN1 antisense RNA 1exerts an oncogenic function in lung adenocarcinoma by regulating DEP domain containing 1 expression via activating epithelial-mesenchymal transition.

Long noncoding RNA (lncRNA) KTN1 antisense RNA 1 (KTN1-AS1) is a novel promoter in the progression of some cancers. However, the knowledge of its role in lung adenocarcinoma is still limited. The current study aimed to examine the biological functions of KTN1-AS1 and its coexpressed protein in lung adenocarcinoma. The RNA sequencing expression profiles from The Cancer Genome Atlas (TCGA) database were downloaded to evaluate the expression of KTN1-AS1 and its coexpressed protein, as well as assess their prognostic values. The correlation between DEP domain containing 1 (DEPDC1) and KTN1-AS1 levels was verified using Pearson's correlation coefficient. Real-time qPCR and western blot were adopted to determine the mRNA and protein levels of the corresponding molecules. Cell viability, invasiveness and motility were assayed by cell counting kit-8, clone formation and Transwell assays, appropriately. High levels of KTN1-AS1 were observed and led to a poorer prognosis in lung adenocarcinoma patients, according to the public dataset. DEPDC1 was found to be a downstream protein associated with KTN1-AS1. Moreover, DEPDC1 was also upregulated in lung adenocarcinoma tissues and can be seen as an independent prognosticator for patients with lung adenocarcinoma. Besides, DEPDC1 expression was positively correlated with KTN1-AS1 expression, which was verified by real-time qPCR and western blot. Functional experiments indicated that KTN1-AS1-knockdown inhibited cells proliferation, migration and invasion, whereas DEPDC1-overexpression could diminish this inhibition. Conversely, overexpression of KTN1-AS1 presented a promoting effect on these phenotypes, whereas silencing DEPDC1 could reduce these accelerations. Further evidence supported that KTN1-AS1/DEPDC1 plays the carcinogenic role by activating the epithelial-mesenchymal transition process and elevating MMP9 expression in lung adenocarcinoma cells. These data suggested that the KTN1-AS1/DEPDC1 axis may involve in the tumorigenesis in lung adenocarcinoma by activating the epithelial-mesenchymal transition process.

DLX6 Antisense RNA 1 Modulates Glucose Metabolism and Cell Growth in Gastric Cancer by Targeting microRNA-4290.

BACKGROUND: Gastric cancer (GC) is one of the most commonly diagnosed malignancy worldwide. DLX6 antisense RNA 1 (DLX6-AS1) is a long noncoding RNA (lncRNA) that exhibits oncogenic effects on multiple human carcinomas. AIMS: This study aimed to investigate the regulatory effect of DLX6-AS1 in GC progression. METHODS: The expression of DLX6-AS1 in GC tissues and cell lines was examined. The cell viability, number of clones, and apoptosis, aerobic glycolysis, and mitochondrial respiration was assessed. The effect of DLX6-AS1 on tumor growth in nude mice was also evaluated. RESULTS: DLX6-AS1 was overexpressed in GC tissues and cell lines. DLX6-AS1 knockdown by short hairpin RNA (shRNA) significantly inhibited cell viability and colony formation, and induced apoptosis. DLX6-AS1 silencing impaired aerobic glycolysis but stimulated mitochondrial respiration in GC cells. miR-4290 was confirmed as a downstream target of DLX6-AS1, and their expression levels were inversely correlated. GC cells expressing sh-DLX6-AS1 showed significantly lower level of 3-phosphoinositide-dependent protein kinase 1 (PDK1), a target of miR-4290, compared to cells expressing control shRNA. In addition, the suppressed GC cell malignancy upon DLX6-AS1 knockdown could be prominently reversed by PDK1 overexpression. Meanwhile, PDK1 overexpression enhanced aerobic glycolysis but repressed mitochondrial respiration under sh-DLX6-AS1 treatment. Furthermore, DLX6-AS1 knockdown significantly delayed the tumor growth in a mouse xenograft model inoculated with GC cells. CONCLUSIONS: LncRNA DLX6-AS1 regulated tumor growth and aerobic glycolysis in GC by targeting miR-4290 and PDK1, suggesting DLX6-AS1 might serve as a novel potential therapeutic target for GC treatment from bench to clinic.

JHDM1D-AS1 aggravates the development of gastric cancer through miR-450a-2-3p-PRAF2 axis.

AIMS: To investigate the molecular function and mechanisms of JHDM1D antisense 1 (JHDM1D-AS1) during gastric cancer (GC) progression. MATERIALS AND METHODS: The qPCR assay was used to detect the JHDM1D-AS1 and miR-450a-2-3p expression levels in GC tissues and cell lines. Bioinformatics analysis was used for exploring the lncRNA-microRNA-mRNA interaction network. We performed dual-luciferase reporter assay and qPCR assay in order to validate the direct interactions. We explored the JHDM1D-AS1 and miR-450a-2-3p on GC progression by using JHDM1D-AS1 siRNA and miR-450a-2-3p inhibitor; in vitro CCK-8 assay, colony formation assay, and invasion assay were conducted. Further, in vivo animal experiments were performed, and the expression levels of miR-450a-2-3p and PRAF2 in the tumor tissues were detected using qPCR and western blot analysis. KEY FINDINGS: The expression levels of JHDM1D-AS1 and miR-450a-2-3p in GC tissues and cell lines were higher and lower as compared to those in the corresponding normal controls, respectively. Moreover, high levels of JHDM1D-AS1 were closely related with metastasis and the GC TNM stage. Functionally, JHDM1D-AS1 depletion caused an obvious reduction in cell proliferation and invasion both in vitro and in vivo, while the addition of miR-450a-2-3p inhibitor could nullify these effects. Mechanically, JHDM1D-AS1 promoted GC progression via the sponging of miR-450a-2-3p in order to increase PRAF2 expression. SIGNIFICANCE: The present results showed that the increased expression of JHDM1D-AS1 was closely associated with tumor progression of GC. JHDM1D-AS1/miR-450a-2-3p/PRAF2 axis may be a promising target for GC treatment.

Antisense Transcription across Nucleotide Repeat Expansions in Neurodegenerative and Neuromuscular Diseases: Progress and Mysteries.

Unstable repeat expansions and insertions cause more than 30 neurodegenerative and neuromuscular diseases. Remarkably, bidirectional transcription of repeat expansions has been identified in at least 14 of these diseases. More remarkably, a growing number of studies has been showing that both sense and antisense repeat RNAs are able to dysregulate important cellular pathways, contributing together to the observed clinical phenotype. Notably, antisense repeat RNAs from spinocerebellar ataxia type 7, myotonic dystrophy type 1, Huntington's disease and frontotemporal dementia/amyotrophic lateral sclerosis associated genes have been implicated in transcriptional regulation of sense gene expression, acting either at a transcriptional or posttranscriptional level. The recent evidence that antisense repeat RNAs could modulate gene expression broadens our understanding of the pathogenic pathways and adds more complexity to the development of therapeutic strategies for these disorders. In this review, we cover the amazing progress made in the understanding of the pathogenic mechanisms associated with repeat expansion neurodegenerative and neuromuscular diseases with a focus on the impact of antisense repeat transcription in the development of efficient therapies.

Evaluation of Arylsulfatase D (ARSD) and long noncoding RNA ARSD-AS1 gene expression in breast cancer patients and their association with oncogenic transcription factors.

PURPOSE: Long non-coding RNAs (LncRNAs) are thought as tumorigenic factors in cancer progression. We investigated the clinical significance of arylsulfatase D (ARSD) and ARSD antisense in breast cancer patients. METHODS: Eighty breast cancer tumors were obtained from the Tumor Bank of Cancer Institute, Imam Khomeini Hospital. The expression level of ARSD and ARSD-AS1 were examined in breast tumors in comparison to the margin of normal tissues using quantitative real-time PCR. Demographic information and the clinicopathologic characteristics including tumor grade, presence of cell receptors, lymph node and vascular invasion were also evaluated. Bioinformatics databases were used for identification of ARSD and ARSD-AS1 molecular targets and their association with cancer. RESULTS: Significant up-regulation of ARSD was observed in tumor tissues in comparison with its antisense (p<0.05). Both ARSD and ARSD-AS1 expression in tumor specimens were notably lower than those in adjacent normal tissue. High expression of ARSD was associated to lower tumor grade (p<0.05). Bioinformatics results revealed the interaction of ARSD with STS and SUMF1 proteins was attributed to the inhibiting of sulfates activity. Also, ARSD co-expressed genes were associated with oncogenic transcription factors, MAF and GATA. TP53 transcription factor site was identified as a target of ARSD-AS1 mRNA. The interaction of this antisense with microRNA (miR-618) could explain its participation in tumor cell proliferation. CONCLUSION: Low expression of ARSD was associated with higher tumor grade. The evidence from this study enhance our understanding of ARSD and ARSD-AS1 function in cancer gene therapy. Accordingly, they could be introduced as great potential targets for breast cancer treatment.

A novel antisense lncRNA NT5E promotes progression by modulating the expression of SYNCRIP and predicts a poor prognosis in pancreatic cancer.

A novel antisense lncRNA NT5E was identified in a previous microarray that was clearly up-regulated in pancreatic cancer (PC) tissues. However, its biological function remains unclear. Thus, we aimed to explore its function and clinical significance in PC. The lncNT5E expression was determined in PC specimens and cell lines. In vitro and in vivo studies detected the impact of lncNT5E depletion on PC cell proliferation, migration and invasion. Western blotting investigated the epithelial-mesenchymal transition (EMT) markers. The interaction between lncNT5E and the promoter region of SYNCRIP was detected by dual-luciferase reporter assay. The role of lncNT5E in modulating SYNCRIP was investigated in vitro. Our results showed that lncNT5E was significantly up-regulated in PC tissues and cell lines and associated with poor prognosis. LncNT5E depletion inhibited PC cell proliferation, migration, invasion and EMT in vitro and caused tumorigenesis arrest in vivo. Furthermore, SYNCRIP knockdown had effects similar to those of lncNT5E depletion. A significant positive relationship was observed between lncNT5E and SYNCRIP. Moreover, the dual-luciferase reporter assays indicated that lncNT5E depletion significantly inhibited SYNCRIP promoter activity. Importantly, the malignant phenotypes of lncNT5E depletion were rescued by overexpressing SYNCRIP. In conclusion, lncNT5E predicts poor prognosis and promotes PC progression by modulating SYNCRIP expression.

Elevation of FGD5-AS1 contributes to cell progression by improving cisplatin resistance against non-small cell lung cancer cells through regulating miR-140-5p/WEE1 axis.

Non-small cell lung cancer (NSCLC) is a common lung cancer with high mortality worldwide. Cisplatin (DDP) resistance is a huge limitation for NSCLC therapy. FGD5 antisense RNA 1 (FGD5-AS1) was recognized as a significant cancer cell regulator. However, the molecular mechanism of FGD5-AS1 in cisplatin resistance of NSCLC cells is poorly understood. FGD5-AS1 and WEE1 expression were up-regulated in DDP-resistant tumors and cells compared with DDP-sensitive ones. Interestingly, down-regulation of FGD5-AS1 or WEE1 inhibited cell proliferation, migration, invasion, autophagy and stimulated cell apoptosis in NSCLC DDP-resistant cells. What's more, restoration of WEE1 abrogated FGD5-AS1 silencing-induced suppression on cell proliferation, migration, invasion, autophagy and promotion on cell apoptosis in NSCLC DDP-resistant cells. Next, we discovered that FGD5-AS1 was able to enhance WEE1 expression by interacting with miR-140-5p. Furthermore, FGD5-AS1 silencing restrained tumor growth of cisplatin-resistant mice. Overexpression of FGD5-AS1 accelerated cell proliferation, migration, invasion and autophagy by enhancing cisplatin resistance against NSCLC cells through miR-140-5p/WEE1 axis, presenting promising biomarkers for the diagnosis of DDP-resistant NSCLC patients.

Sense-antisense miRNA pairs constitute an elaborate reciprocal regulatory circuit.

Antisense transcription of protein-coding genes has been increasingly recognized as an important regulatory mechanism of gene expression. However, less is known about the extent and importance of antisense transcription of noncoding genes. Here, we investigate the breadth and dynamics of antisense transcription of miRNAs, a class of important noncoding RNAs. Because the antisense transcript of a miRNA is likely to form a hairpin suitable as the substrate of ADARs, which convert adenosine to inosine in double-stranded RNAs, we used A-to-I RNA editing as ultrasensitive readout for antisense transcription of the miRNAs. Through examining the unstranded targeted RNA-seq libraries covering all miRNA loci in 25 types of human tissues, we identified 7275 editing events located in 81% of the antisense strand of the miRNA loci, thus uncovering the previously unknown prevalent antisense transcription of the miRNAs. We found that antisense transcripts are tightly regulated, and a substantial fraction of miRNAs and their antisense transcripts are coexpressed. Sense miRNAs have been shown to down-regulate the coexpressed antisense transcripts, whereas the act of antisense transcription, rather than the transcripts themselves, regulates the expression of sense miRNAs. RNA editing tends to decrease the miRNA accessibility of the antisense transcripts, therefore protecting them from being degraded by the sense-mature miRNAs. Altogether, our study reveals the landscape of antisense transcription and editing of miRNAs, as well as a previously unknown reciprocal regulatory circuit of sense-antisense miRNA pairs.

TMPO-AS1/miR-98-5p/EBF1 feedback loop contributes to the progression of bladder cancer.

As reported in numerous studies, long non-coding RNAs (lncRNAs) exert significant effect on the regulation of tumor development. LncRNA TMPO antisense RNA 1 (TMPO-AS1) has been confirmed to be implicated in the development of several cancers. However, its clinical significance is still largely unknown in bladder cancer (BCa). In this study, high expression of TMPO-AS1 was revealed in BCa tissues and cell lines, and TMPO-AS1 predicted poor prognosis. Moreover, TMPO-AS1 facilitated cell growth. Additionally, TMPO-AS1 also boosted the migration and invasion of BCa cells. Mechanistically, overexpressed EBF transcription factor 1 (EBF1) in BCa cell was verified to promote the transcription of TMPO-AS1. Later, we found that TMPO-AS1 was a cytoplasmic RNA and could sponge miR-98-5p. Besides, it was validated that EBF1 is a target gene of miR-98-5p and negatively correlated with miR-98-5p in terms of expression level. According to the results of rescue experiments, we observed that EBF1 overexpression restored the repressive effect of TMPO-AS1 silencing on BCa development. Our research is the first to disclose the biological role and molecular mechanism of TMPO-AS1 in BCa, and TMPO-AS1 might be identified as a new therapeutic target for BCa patients.

Long Noncoding RNA DLX6-AS1 Promotes the Progression in Cervical Cancer by Targeting miR-16-5p/ARPP19 Axis.

Background: Cervical cancer (CC) is regarded as one of the most common gynecological malignancies. LncRNA DLX6-AS1 has been proven vital in various cancers, whereas its exact function is still largely unestablished in CC. Materials and Methods: The expression pattern of DLX6-AS1 and miR-16-5p in CC cells was determined by real-time quantitative polymerase chain reaction (RT-qPCR). ARPP19 expression was assessed by RT-qPCR and Western blot assays in CC cells. The precise function of DLX6-AS1 in CC was detected by Cell-Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), caspase-3 activity, transwell, and Western blot experiments. RNA immunoprecipitation (RIP) and luciferase reporter assays were employed to certify the combination between miR-16-5p and DLX6-AS1 (or ARPP19). Nuclear cytoplasmic segmentation determined the localization of DLX6-AS1 in CC cells. A xenograft mouse model assay studied the influences of DLX6-AS1 silencing on CC progression in vivo. Results: Elevated DLX6-AS1 expression was disclosed in CC cells. DLX6-AS1 silence attenuated proliferation, migration, and epithelial-mesenchymal transition program as well as enhanced CC cell apoptosis. DLX6-AS1 was uncovered to sponge and negatively modulate miR-16-5p in CC. Besides, ARPP19 was uncovered as a downstream target gene of miR-16-5p in CC. Rescue experiments indicated that DLX6-AS1 enhanced the cellular process of CC cells through upregulating ARPP19. Moreover, in vivo assay confirmed that DLX6-AS1 promoted CC growth. Conclusions: DLX6-AS1 accelerates the progression of CC through sponging miR-16-5p and upregulates ARPP19, which offers a novel insight into prognosis and remedy of CC.

Synthesis of low immunogenicity RNA with high-temperature in vitro transcription.

The use of synthetic RNA for therapeutics requires that the in vitro synthesis process be robust and efficient. The technology used for the synthesis of these in vitro-transcribed RNAs, predominantly using phage RNA polymerases (RNAPs), is well established. However, transcripts synthesized with RNAPs are known to display an immune-stimulatory activity in vivo that is often undesirable. Previous studies have identified double-stranded RNA (dsRNA), a major by-product of the in vitro transcription (IVT) process, as a trigger of cellular immune responses. Here we describe the characterization of a high-temperature IVT process using thermostable T7 RNAPs to synthesize functional mRNAs that demonstrate reduced immunogenicity without the need for a post-synthesis purification step. We identify features that drive the production of two kinds of dsRNA by-products-one arising from 3' extension of the run-off product and one formed by the production of antisense RNAs-and demonstrate that at a high temperature, T7 RNAP has reduced 3'-extension of the run-off product. We show that template-encoded poly(A) tailing does not affect 3'-extension but reduces the formation of the antisense RNA by-products. Combining high-temperature IVT with template-encoded poly(A) tailing prevents the formation of both kinds of dsRNA by-products generating functional mRNAs with reduced immunogenicity.

CTCF-induced upregulation of HOXA11-AS facilitates cell proliferation and migration by targeting miR-518b/ACTN4 axis in prostate cancer.

BACKGROUND: Testified as crucial participators in different types of human malignancies, long noncoding RNAs (lncRNAs) have been revealed to exert a significant effect on the complicated courses of tumor progression. Although existing literatures have revealed the oncogenic role of lncRNA homeobox A11 antisense RNA (HOXA11-AS) in multiple cancers, the underlying role of HOXA11-AS in prostate cancer (PCa) and its potential molecular mechanism remains poorly understood. AIM: To decipher the molecular performance of HOXA11-AS in PCa. METHODS: The expression of HOXA11-AS, miR-518b and actinin alpha 4 (ACTN4) was detected by a real-time quantitative polymerase chain reaction. Colony formation, EdU, flow cytometry, wound healing, and transwell assays were utilized to explore the biological role of HOXA11-AS in PCa. The interaction between RNAs (CCCTC-binding factor [CTCF], HOXA11-AS, miR-518b, and ACTN4) was tested via chromatin immunoprecipitation, luciferase reporter and RNA immunoprecipitation assays. RESULTS: HOXA11-AS in PCa cells was expressed at high levels. Silenced HOXA11-AS in PCa cells could lead to a significant elevation in the abilities of cell proliferation and migration whereas a remarkable declination in cell apoptosis capability. Subsequent molecular mechanism assays confirmed that HOXA11-AS bound with miR-518b and negatively regulates miR-518b expression. Besides, HOXA11-AS could regulate the expression of ACTN4 by sponging miR-518b. Moreover, rescued-function assays revealed that miR-518b inhibition or ACTN4 upregulation reversed the repressive effect of HOXA11-AS knockdown on PCa progression. Furthermore, CTCF was validated to activate HOXA11-AS transcription in PCa cells. CONCLUSIONS: CTCF-induced upregulation of HOXA11-AS facilitates PCa progression via miR-518b/ACTN4 axis, providing a new target for PCa treatment.

Regulatory RNA at the crossroads of carbon and nitrogen metabolism in photosynthetic cyanobacteria.

Cyanobacteria are photosynthetic bacteria that populate widely different habitats. Accordingly, cyanobacteria exhibit a wide spectrum of lifestyles, physiologies, and morphologies and possess genome sizes and gene numbers which may vary by up to a factor of ten within the phylum. Consequently, large differences exist between individual species in the size and complexity of their regulatory networks. Several non-coding RNAs have been identified that play crucial roles in the acclimation responses of cyanobacteria to changes in the environment. Some of these regulatory RNAs are conserved throughout the cyanobacterial phylum, while others exist only in a few taxa. Here we give an overview on characterized regulatory RNAs in cyanobacteria, with a focus on regulators of photosynthesis, carbon and nitrogen metabolism. However, chances are high that these regulators represent just the tip of the iceberg.

R-Loops Promote Antisense Transcription across the Mammalian Genome.

Widespread antisense long noncoding RNA (lncRNA) overlap with many protein-coding genes in mammals and emanate from gene promoter, enhancer, and termination regions. However, their origin and biological purpose remain unclear. We show that these antisense lncRNA can be generated by R-loops that form when nascent transcript invades the DNA duplex behind elongating RNA polymerase II (Pol II). Biochemically, R-loops act as intrinsic Pol II promoters to induce de novo RNA synthesis. Furthermore, their removal across the human genome by RNase H1 overexpression causes the selective reduction of antisense transcription. Consequently, we predict that R-loops act to facilitate the synthesis of many gene proximal antisense lncRNA. Not only are R-loops widely associated with DNA damage and repair, but we now show that they have the capacity to promote de novo transcript synthesis that may have aided the evolution of gene regulation.

Interferon-inducible lncRNA IRF1-AS represses esophageal squamous cell carcinoma by promoting interferon response.

Interferons (IFNs) play crucial roles in the development and treatment of cancer. Long non-coding RNAs (lncRNAs) are emerging molecules involved in cancer progression. Here, we identified and characterized an IFN-inducible nuclear lncRNA IRF1-AS (Interferon Regulatory Factor 1 Antisense RNA) which was positively correlated with IRF1 expression. IFNs upregulate IRF1-AS via the JAK-STAT pathway. Knockdown and overexpression of IRF1-AS revealed that IRF1-AS inhibits oesophageal squamous cell carcinoma (ESCC) proliferation and promotes apoptosis in vitro and in vivo. Mechanistically, IRF1-AS activates IRF1 (Interferon Regulatory Factor 1) transcription through interacting with ILF3 (Interleukin Enhancer Binding Factor 3) and DHX9 (DExH-Box Helicase 9). In turn, IRF1 binds to the IRF1-AS promoter directly and activates IRF1-AS transcription. Global analysis of IRF1-AS-regulated genes indicated that IRF1-AS activates the IFN response in vitro and in vivo. IRF1 knockdown in IRF1-AS-overexpressing cells abolished the antiproliferative effect and activation of the IFN response. Furthermore, IRF1-AS was downregulated in ESCC tissues, and low expression correlated with poor prognosis. In conclusion, the interferon-inducible lncRNA IRF1-AS represses esophageal squamous cell carcinoma progression by promoting interferon response through a positive regulatory loop with IRF1.

Prognostic value of lncRNA FEZF1 antisense RNA 1 over-expression in oncologic outcomes of patients with solid tumors.

BACKGROUND: FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1), as a novel lncRNA, was reported to be up-regulated in various cancers and involved in tumor progression. This study systematically assessed the prognostic value of FEZF1-AS1 in solid tumors. METHODS: Web of Science, PubMed, EMBASE, Chinese National Knowledge Infrastructure, and Wanfang databases were searched for eligible studies that evaluated the prognostic role of FEZF1-AS1 expression in cancer patients. Pooled hazard ratios (HRs) and combined odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated. The meta-analysis was conducted using Stata/SE 14.1. RESULTS: Fifteen original studies involving 1378 patients were enrolled. Pooled results showed that increased expression of FEZF1-AS1 significantly correlated with shorter overall survival (OS) in cancer patients (HR 2.04, 95% CI 1.60-2.47), and also shorter disease-free survival (DFS) (HR 2.08, 95% CI 1.27-2.89). Additionally, the combined ORs indicated that increased FEZF1-AS1 expression was significantly associated with lymph node metastasis (OR 3.35, 95% CI 1.98-5.67), distant metastasis (OR 3.10, 95% CI 1.86-5.15), poor tumor differentiation (OR 2.90, 95% CI 1.45-5.80), high depth of tumor invasion (OR 2.72, 95% CI 1.36-5.43), and advanced clinical stage (OR 2.76, 95% CI 1.75-4.35). Expression analysis using the Gene Expression Profiling Interactive Analysis database indicated that the expression of FEZF1-AS1 was higher in tumor tissues than that in the corresponding normal tissues. The results of survival analysis revealed that increased FEZF1-AS1 expression was correlated with poor OS and DFS in cancer patients. CONCLUSIONS: LncRNA FEZF1-AS1 may serve as a valuable prognostic biomarker for clinical outcomes in various solid tumors.

ZEA exerts toxic effects on reproduction and development by mediating Dio3os in mouse endometrial stromal cells.

Zearalenone (ZEA) and imprinted long noncoding RNAs (lncRNAs) are both closely related to reproduction and development. However, whether they have connections in regulating reproduction and development is not clear yet. The aim of this research is to investigate their relationship. lncRNA microarray was performed to analyze differentially expressed genes, and real-time quantitative polymerase chain reaction (PCR) was used to verify the accuracy of microarray analysis. Meanwhile, the technologies of rapid amplification of cDNA ends, RNA fluorescence in situ hybridization and bioinformatics were adopted to characterize the selected lncRNA. Analysis of lncRNA microarray showed lncRNAs and messenger RNAs related to reproduction and development were significantly differently expressed, and Dio3os was probably the target lncRNA. Then, the experiment of real-time quantitative PCR verified the accuracy of microarray data. Characterization of Dio3os showed Dio3os, an antisense lncRNA with 2312 bp and 15 open reading frames, was enriched in the cytoplasm. Our findings suggest ZEA probably exerts toxic effects on reproduction and development by mediating Dio3os.