Long noncoding RNA-based chromatin control of germ cell differentiation: a yeast perspective

Long Noncoding RNAs Responding to Ethanol Stress in Yeast Seem Associated with Protein Synthesis and Membrane Integrity

Background/Objectives: Translation and the formation of membraneless organelles are linked mechanisms to promote cell stress surveillance. LncRNAs responsive to ethanol stress transcr_9136 of the SEY6210 strain and transcr_10027 of the BY4742 strain appear to act on tolerance to ethanol in these strains. Here, we investigate whether the ethanol responsiveness of transcr_9136 and transcr_10027 and their role in ethanol stress are associated with protein biogenesis and membraneless organelle assembly. Methods: SEY6210 transcr_9136∆ and BY4742 transcr_10027∆ and their wild-type counterparts were subjected to their maximum ethanol-tolerant stress. The expression of the transcr_9136, transcr_10027, ILT1, RRP1, 27S, 25S, TIR3, and FAA3 genes was accessed by qPCR. The level of DCP1a, PABP, and eIF4E proteins was evaluated by Western blotting. Bioinformatics analyses allowed us to check whether transcr_9136 may regulate the expression of RRP1 and predict the interaction between transcr_10027 and Tel1p. The cell death rate of SEY6210 strains under control and ethanol stress conditions was assessed by flow cytometry. Finally, we evaluated the total protein yield of all strains analyzed. Results: The results demonstrated that transcr_9136 of SEY6210 seems to control the expression of RRP1 and 27S rRNA and reduce the general translation. Furthermore, transcr_9136 seems to act on cell membrane integrity. Transcr_10027 of BY4742 appears to inhibit processing body formation and induce a general translation level. Conclusions: This is the first report on the effect of lncRNAs on yeast protein synthesis and new mechanisms of stress-responsive lncRNAs in yeast, with potential industrial applications such as ethanol production.

Genome-wide identification of long non-coding RNA for Botrytis cinerea during infection to tomato (Solanum lycopersicum) leaves

Long non-coding RNA (lncRNA) plays important roles in animals and plants. In filamentous fungi, however, their biological function in infection stage has been poorly studied. Here, we investigated the landscape and regulation of lncRNA in the filamentous plant pathogenic fungus Botrytis cinerea by strand-specific RNA-seq of multiple infection stages. In total, 1837 lncRNAs have been identified in B. cinerea. A large number of lncRNAs were found to be antisense to mRNAs, forming 743 sense-antisense pairs, of which 55 antisense lncRNAs and their respective sense transcripts were induced in parallel as the infection stage. Although small RNAs were produced from these overlapping loci, antisense lncRNAs appeared not to be involved in gene silencing pathways. In addition, we found the alternative splicing events occurred in lncRNA. These results highlight the developmental stage-specific nature and functional potential of lncRNA expression in the infection stage and provide fundamental resources for studying infection stage-induced lncRNAs.

The Role of Long Intergenic Noncoding RNA in Fetal Development

The role of long intergenic noncoding RNAs (lincRNAs) in fetal development has emerged as a significant area of study, challenging the traditional protein-centric view of gene expression. While messenger RNAs (mRNAs) have long been recognized for their role in encoding proteins, recent advances have illuminated the critical functions of lincRNAs in various biological processes. Initially identified through high-throughput sequencing technologies, lincRNAs are transcribed from intergenic regions between protein-coding genes and exhibit unique regulatory functions. Unlike mRNAs, lincRNAs are involved in complex interactions with chromatin and chromatin-modifying complexes, influencing gene expression and chromatin structure. LincRNAs are pivotal in regulating tissue-specific development and embryogenesis. For example, they are crucial for proper cardiac, neural, and reproductive system development, with specific lincRNAs being associated with organogenesis and differentiation processes. Their roles in embryonic development include regulating transcription factors and modulating chromatin states, which are essential for maintaining developmental programs and cellular identity. Studies using RNA sequencing and genetic knockout models have highlighted the importance of lincRNAs in processes such as cell differentiation, tissue patterning, and organ development. Despite their functional significance, the comprehensive annotation and understanding of lincRNAs remain limited. Ongoing research aims to elucidate their mechanisms of action and potential applications in disease diagnostics and therapeutics. This review summarizes current knowledge on the functional roles of lincRNAs in fetal development, emphasizing their contributions to tissue-specific gene regulation and developmental processes.

Chromatin-associated YTHDC1 coordinates heat-induced reprogramming of gene expression

Heat stress (HS) induces a cellular response leading to profound changes in gene expression. Here, we show that human YTHDC1, a reader of N⁶-methyladenosine (m⁶A) RNA modification, mostly associates to the chromatin fraction and that HS induces a redistribution of YTHDC1 across the genome, including to heat-induced heat shock protein (HSP) genes. YTHDC1 binding to m⁶A-modified HSP transcripts co-transcriptionally promotes expression of HSPs. In parallel, hundreds of the genes enriched in YTHDC1 during HS have their transcripts undergoing YTHDC1- and m⁶A-dependent intron retention. Later, YTHDC1 concentrates within nuclear stress bodies (nSBs) where it binds to m⁶A-modified SATIII non-coding RNAs, produced in an HSF1-dependent manner upon HS. These findings reveal that YTHDC1 plays a central role in a chromatin-associated m⁶A-based reprogramming of gene expression during HS. Furthermore, they support the model where the subsequent and temporary sequestration of YTHDC1 within nSBs calibrates the timing of this YTHDC1-dependent gene expression reprogramming.

The OsIME4 gene identified as a key to meiosis initiation by RNA in situ hybridization

The formation of asexual seeds in plants holds great promise as a breeding system for one-line hybrid rice. Entry into meiosis is a key developmental decision in gametogenesis, especially in formation of asexual seeds in plants. Apomeiosis in MeMCs can be achieved by identifying and manipulating meiosis-specific genes. Using methods based on in situ hybridization and expression analysis, we identified OsIME4 (inducer of meiosis 4) sense and antisense transcripts involved in rice meiosis initiation, similar to initiation of meiosis in budding yeast. Our data suggest that the OsIME4 sense transcript, which encodes a putative mRNA N6-adenosine methyltransferase, keeps rice cells at mitosis stage through some form of epigenesis (DNA/RNA methylation), and the non-coding antisense transcript of OsIME4 converts the cell status from mitosis to meiosis by inhibiting expression (transcription and translation) of the sense transcript. We identified that the non-coding antisense transcript of OsIME4 converts archesporial cell status from mitosis to meiosis by inhibiting expression of the OsIME4 sense transcript in rice. Our results provide novel insights into meiosis initiation in rice and for engineering of apomixis in sexual crops by manipulating the OsIME4 sense and antisense transcripts, which has great promise for producing apomictic rice in the future.

Long Non-Coding RNAs in the Control of Gametogenesis: Lessons from Fission Yeast

Long non-coding RNAs (lncRNAs) contribute to cell fate decisions by modulating genome expression and stability. In the fission yeast Schizosaccharomyces pombe, the transition from mitosis to meiosis results in a marked remodeling of gene expression profiles, which ultimately ensures gamete production and inheritance of genetic information to the offspring. This key developmental process involves a set of dedicated lncRNAs that shape cell cycle-dependent transcriptomes through a variety of mechanisms, including epigenetic modifications and the modulation of transcription, post-transcriptional and post-translational regulations, and that contribute to meiosis-specific chromosomal events. In this review, we summarize the biology of these lncRNAs, from their identification to mechanism of action, and discuss their regulatory role in the control of gametogenesis.

Antifungal Effect of Long Noncoding RNA 9708-1 in the Vulvovaginal Candidiasis Murine Model

Vulvovaginal candidiasis (VVC) caused by Candida spp. affects 70–75% of women at least once during their lives. We aim to elucidate the potential mechanism of VVC and investigate the therapeutic effects of long noncoding RNA 9708-1. Female BALB/c mice were randomized to four treatment groups, including the blank control group, VVC control group, vehicle control group and lncRNA 9708-1-overexpressed group. Mice were euthanized on Day 4, Day 7 and Day 14 after treatment. Colony-forming unit (CFU) was measured, and the inflammation was detected by hematoxylin and eosin (H&E). Gene and protein expression levels of lncRNA 9708-1 and FAK were determined by real-time PCR, Western blot and immunohistochemistry. The overexpression of lncRNA 9708-1 significantly decreased the fungal load from Day 4 to 7. H&E staining indicated that the impaired histological profiles were improved in lncRNA 9708-1-overexpressed group. LncRNA 9708-1 led to a significant increase in FAK level of vagina tissue which is expressed mainly in epithelial basal layer. This study suggests that lncRNA 9708-1 played a protective role on murine experimental VVC by upregulating the expression levels of FAK.

CPF Recruitment to Non-canonical Transcription Termination Sites Triggers Heterochromatin Assembly and Gene Silencing

In eukaryotic genomes, heterochromatin is targeted by RNAi machinery and/or by pathways requiring RNA elimination and transcription termination factors. However, a direct connection between termination machinery and RNA polymerase II (RNAPII) transcriptional activity at heterochromatic loci has remained elusive. Here, we show that, in fission yeast, the conserved cleavage and polyadenylation factor (CPF) is a key component involved in RNAi-independent assembly of constitutive and facultative heterochromatin domains and that CPF is broadly required to silence genes regulated by Clr4^SUV39H. Remarkably, CPF is recruited to non-canonical termination sites within the body of genes by the YTH family RNA-binding protein Mmi1 and is required for RNAPII transcription termination and facultative heterochromatin assembly. CPF loading by Mmi1 also promotes the selective termination of long non-coding RNAs that regulate gene expression in cis. These analyses delineate a mechanism in which CPF loaded onto non-canonical termination sites specifies targets of heterochromatin assembly and gene silencing.

Long Noncoding RNA HOTTIP Serves as an Independent Predictive Biomarker for the Prognosis of Patients with Clear Cell Renal Cell Carcinoma

Several studies have indicated that HOXA transcript at the distal tip (HOTTIP) play important roles in the tumorigenesis and development of various cancers. We aim to investigate the expression and prognostic value of HOTTIP in clear cell renal cell carcinoma (ccRCC). A systematic review of PubMed, Embase, Medline, and Web of Science databases was performed to select eligible literatures relevant to the correlation between HOTTIP expression and clinical outcome of different cancers. The association between the HOTTIP level and overall survival (OS), lymph node metastasis (LNM), or clinical stage was subsequently analyzed. Survival analyses were performed in a large cohort of more than 500 patients with ccRCC from The Cancer Genome Atlas (TCGA) using bioinformatic methods. Seventeen studies with a total of 1594 patients with thirteen kinds of carcinomas were included in this analysis. The result showed that high HOTTIP expression could predict worse outcome in cancer patients, with the pooled hazard ratio (HR) of 2.34 (95% confidence interval (CI) 1.96–2.79, p < 0.0001). The result also showed that elevated HOTTIP expression was correlated with more LNM (OR = 2.61, 95% CI 1.91-3.58, p < 0.0001) and advanced clinical stage (OR = 3.57, 95% CI 2.58-4.93, p < 0.0001). We further validated that ccRCC patients with higher HOTTIP expression tend to have unsatisfactory outcomes both in the entire TCGA dataset and different clinical stratums, like age, grade, and stage. The tumor of those patients was associated with a larger size, easier to metastasis, advanced clinical stage, and a higher pathological grade. These findings suggested that increased HOTTIP expression might act as a novel prognostic marker for ccRCC patients.

Long noncoding RNA TUG1 regulates prostate cancer cell proliferation, invasion and migration via the Nrf2 signaling axis

BACKGROUND

Long noncoding RNAs (lncRNAs) have been identified to modulate the development and progression of prostate cancer (PCa) via the regulation of their target genes. However, the biological function underlying the effect of lncRNA TUG1 in PCa remains unclear.

METHODS

Reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and Western blotting analysis were used to assess the mRNA expression of TUG1 and protein expression levels of Nrf2 pathway members, respectively. The migration, invasion, and proliferation abilities of cells were assessed by the wound-healing, Transwell migration/invasion, and CCK8 assays, respectively.

RESULTS

TUG1 was strikingly upregulated in PCa cells compared with non-tumorigenic human prostate epithelial cells. The LncTar Web Server, which is a bioinformatics tool, was used to predict the target association between TUG1 and Nrf2. Moreover, the expression of TUG1 showed a strikingly positive correlation with that of Nrf2 in TCGA PCa RNA-Seq data (r = 0.26,P = 4.63E-09). Subsequently, inhibition of TUG1 using siRNA resulted in deceased proliferation, migration, and invasion of PCa cells; however, these effects were reversed by treatment with oltipraz (an activator of Nrf2). Finally, we evaluated the Nrf2 pathway to reveal the underlying mechanism of TUG1 in PCa cells, and found that TUG1 knockdown decreased the protein expression of Nrf2 downstream members (e.g., HO-1, FTH1, and NQO1).

CONCLUSIONS

LncRNA TUG1 plays an oncogenic role in human PCa cells by promoting the cell proliferation and invasion in PCa cell lines, at least partly via the Nrf2 signaling pathway.

XRN1-associated long non-coding RNAs may contribute to fungal virulence and sexual development in entomopathogenic fungus Cordyceps militaris

BACKGROUND

Numerous long non-coding RNAs (lncRNAs) identified and characterized in mammals, plants, and fungi have been found to play critical regulatory roles in biological processes. However, little is known about the role of lncRNAs in insect pathogenic fungi.

RESULTS

By profiling the transcriptomes of sexual and asexual development in the insect-pathogenic fungus Cordyceps militaris, 4140 lncRNAs were identified and found to be dynamically expressed during fungal development. The lncRNAs had shorter transcript lengths and lower numbers of exons compared to protein-coding genes. The expressed target genes (neighboring and cis-regulated) of various expressed lncRNAs were predicted, and these genes showed significant enrichment in energy metabolism and signaling pathways, such as 'Glycolysis/Gluconeogenesis' and "MAPK signaling pathway". To better understand how lncRNAs function in the fungus, xrn1, the final gene of the NMD pathway, which determines the fate of lncRNAs, was disrupted. The Δxrn1 deletion mutant displayed significant (P < 0.05) attenuation of virulence and a lower growth rate in C. militaris. Quantitative RT-PCR results revealed 10 lncRNAs with significantly higher expression, while 8 of these 10 lncRNA target genes (virulence- and sexual development-related) showed significantly lower expression in Δxrn1 compared to in the wild-type, suggesting that lncRNA expression regulates fungal virulence and sexual development by affecting gene expression.

CONCLUSION

These findings suggest that lncRNAs in C. militaris play important roles in the fungal infection progress and fruiting body production, providing a broad repertoire and resource for further studies of lncRNAs. © 2019 Society of Chemical Industry.

Developmental Dynamics of Long Noncoding RNA Expression during Sexual Fruiting Body Formation in Fusarium graminearum

Long noncoding RNA (lncRNA) plays important roles in sexual development in eukaryotes. In filamentous fungi, however, little is known about the expression and roles of lncRNAs during fruiting body formation. By profiling developmental transcriptomes during the life cycle of the plant-pathogenic fungus Fusarium graminearum, we identified 547 lncRNAs whose expression was highly dynamic, with about 40% peaking at the meiotic stage. Many lncRNAs were found to be antisense to mRNAs, forming 300 sense-antisense pairs. Although small RNAs were produced from these overlapping loci, antisense lncRNAs appeared not to be involved in gene silencing pathways. Genome-wide analysis of small RNA clusters identified many silenced loci at the meiotic stage. However, we found transcriptionally active small RNA clusters, many of which were associated with lncRNAs. Also, we observed that many antisense lncRNAs and their respective sense transcripts were induced in parallel as the fruiting bodies matured. The nonsense-mediated decay (NMD) pathway is known to determine the fates of lncRNAs as well as mRNAs. Thus, we analyzed mutants defective in NMD and identified a subset of lncRNAs that were induced during sexual development but suppressed by NMD during vegetative growth. These results highlight the developmental stage-specific nature and functional potential of lncRNA expression in shaping the fungal fruiting bodies and provide fundamental resources for studying sexual stage-induced lncRNAs.

Fusarium graminearum is the causal agent of the head blight on our major staple crops, wheat and corn. The fruiting body formation on the host plants is indispensable for the disease cycle and epidemics. Long noncoding RNA (lncRNA) molecules are emerging as key regulatory components for sexual development in animals and plants. To date, however, there is a paucity of information on the roles of lncRNAs in fungal fruiting body formation. Here we characterized hundreds of lncRNAs that exhibited developmental stage-specific expression patterns during fruiting body formation. Also, we discovered that many lncRNAs were induced in parallel with their overlapping transcripts on the opposite DNA strand during sexual development. Finally, we found a subset of lncRNAs that were regulated by an RNA surveillance system during vegetative growth. This research provides fundamental genomic resources that will spur further investigations on lncRNAs that may play important roles in shaping fungal fruiting bodies.

A current view on long noncoding RNAs in yeast and filamentous fungi

Long noncoding RNAs (lncRNAs) are crucial players in epigenetic regulation. They were initially discovered in human, yet they emerged as common factors involved in a number of central cellular processes in several eukaryotes. For example, in the past decade, research on lncRNAs in yeast has steadily increased. Several examples of lncRNAs were described in Saccharomyces cerevisiae and Schizosaccharomyces pombe. Also, screenings for lncRNAs in ascomycetes were performed and, just recently, the first full characterization of a lncRNA was performed in the filamentous fungus Trichoderma reesei. In this review, we provide a broad overview about currently known fugal lncRNAs. We make an attempt to categorize them according to their functional context, regulatory strategies or special properties. Moreover, the potential of lncRNAs as a biotechnological tool is discussed.

LncRNA TUG1 promoted viability and associated with gemcitabine resistant in pancreatic ductal adenocarcinoma

OBJECTIVE

To investigate the underlying mechanism of lncRNA TUG1 in pancreatic ductal adenocarcinoma (PDAC).

METHODS

The expression of TUG1 was defined by qRT-PCR. The apoptotic cells were detected by flow cytometry assay. The cell migration and invasion were measured by scratch assay and Transwell assay. The level of ERK pathway was detected using Western blot.

RESULTS

Compared with normal tissues and cells, the expression of TUG1 was up-regulated in pancreatic cancer tissue and cells. Meanwhile, knockdown of TUG1 could promote PDAC cells apoptosis and inhibit PDAC cells viability, migration and invasion. In addition, overexpression of TUG1 enhanced the gemcitabine chemoresistance of PDAC cells. Surprisingly, gemcitabine combined with SCH772984 (a suppressor of ERK pathway) could reverse the drug resistance resulted from overexpression of TUG1.

CONCLUSION

TUG1 promoted the viability of PDAC cells and enhanced its resistance of gemcitabine.

GDV1 induces sexual commitment of malaria parasites by antagonizing HP1-dependent gene silencing

Malaria is caused by Plasmodium parasites that proliferate in the bloodstream. During each replication cycle, some parasites differentiate into gametocytes, the only forms able to infect the mosquito vector and transmit malaria. Sexual commitment is triggered by activation of AP2-G, the master transcriptional regulator of gametocytogenesis. Heterochromatin protein 1 (HP1)-dependent silencing of ap2-g prevents sexual conversion in proliferating parasites. In this study, we identified Plasmodium falciparum gametocyte development 1 (GDV1) as an upstream activator of sexual commitment. We found that GDV1 targeted heterochromatin and triggered HP1 eviction, thus derepressing ap2-g Expression of GDV1 was responsive to environmental triggers of sexual conversion and controlled via a gdv1 antisense RNA. Hence, GDV1 appears to act as an effector protein that induces sexual differentiation by antagonizing HP1-dependent gene silencing.

Long noncoding RNAs that respond to Fusarium oxysporum infection in 'Cavendish' banana (Musa acuminata)

Long noncoding RNAs (lncRNAs) are a class of genes that influence a variety of biological functions through acting as signal, decoy, guide, and scaffold molecules. In banana (Musa spp.), an important economic fruit crop, particularly in Southeast Asia, the wilt disease caused by Fusarium oxysporum f. sp. cubense (Foc), especially strain Foc TR4, is disastrous. In banana, how the biogenesis of these lncRNAs is regulated in response to pathogen infection is still largely unknown. In this study, strand-specific paired-end RNA sequencing of banana samples was performed on susceptible and resistant cultivars inoculated with Foc, with three biological replicates and at two different times after infection. Overall, 5,294 lncRNAs were predicted with high confidence through strict filtration, including long intergenic ncRNA (lincRNA) and antisense lncRNA. Differentially expressed (DE) lncRNAs were identified in response to Foc infection in the inoculated versus the mock-inoculated banana of the susceptible 'BX' and resistant 'NK' cultivars. Through KEGG, GO, and the expression levels of the DE lncRNAs, some DE lncRNAs were predicted to be involved in plant-pathogen interactions and phytohormone signal transduction. In this study, this catalog of lncRNAs and their properties will facilitate further experimental studies and functional classifications of these genes.

Selective termination of lncRNA transcription promotes heterochromatin silencing and cell differentiation

Long non-coding RNAs (lncRNAs) regulating gene expression at the chromatin level are widespread among eukaryotes. However, their functions and the mechanisms by which they act are not fully understood. Here, we identify new fission yeast regulatory lncRNAs that are targeted, at their site of transcription, by the YTH domain of the RNA-binding protein Mmi1 and degraded by the nuclear exosome. We uncover that one of them, nam1, regulates entry into sexual differentiation. Importantly, we demonstrate that Mmi1 binding to this lncRNA not only triggers its degradation but also mediates its transcription termination, thus preventing lncRNA transcription from invading and repressing the downstream gene encoding a mitogen-activated protein kinase kinase kinase (MAPKKK) essential to sexual differentiation. In addition, we show that Mmi1-mediated termination of lncRNA transcription also takes place at pericentromeric regions where it contributes to heterochromatin gene silencing together with RNA interference (RNAi). These findings reveal an important role for selective termination of lncRNA transcription in both euchromatic and heterochromatic lncRNA-based gene silencing processes.

Genome-wide long non-coding RNA screening, identification and characterization in a model microorganism Chlamydomonas reinhardtii

Microalgae are regarded as the most promising biofuel candidates and extensive metabolic engineering were conducted but very few improvements were achieved. Long non-coding RNA (lncRNA) investigation and manipulation may provide new insights for this issue. LncRNAs refer to transcripts that are longer than 200 nucleotides, do not encode proteins but play important roles in eukaryotic gene regulation. However, no information of potential lncRNAs has been reported in eukaryotic alga. Recently, we performed RNA sequencing in Chlamydomonas reinhardtii, and obtained totally 3,574 putative lncRNAs. 1440 were considered as high-confidence lncRNAs, including 936 large intergenic, 310 intronic and 194 anti-sense lncRNAs. The average transcript length, ORF length and numbers of exons for lncRNAs are much less than for genes in this green alga. In contrast with human lncRNAs of which more than 98% are spliced, the percentage in C. reinhardtii is only 48.1%. In addition, we identified 367 lncRNAs responsive to sulfur deprivation, including 36 photosynthesis-related lncRNAs. This is the first time that lncRNAs were explored in the unicellular model organism C. reinhardtii. The lncRNA data could also provide new insights into C. reinhardtii hydrogen production under sulfur deprivation.

Long non-coding RNA UCA1 promotes the tumorigenesis in pancreatic cancer

The contribution of long non-coding RNAs (lncRNAs) to tumorigenesis and metastasis of pancreatic cancer (PC) remains largely unknown. Urothelial cancer-associated 1 (UCA1), which is an originally identified lncRNA in bladder cancer, has be proved to play a pivotal role in bladder cancer progression and embryonic development. In this study, we detected the mRNA expression of UCA1 in 128 PC patients by qRT-PCR, and found that UCA1 expression was significantly, up-regulated in tumor tissues than that in matched adjacent non-tumor tissues (p<0.05). Clinicopathological analysis demonstrated that UCA1 expression in PC significantly correlated with malignant potential factors such as tumor size (p=0.021), depth of invasion (p=0.033), CA19-9 level (p=0.034) and tumor stage (p=0.013). Cox proportional hazards regression analysis also confirmed that high UCA1 expression was an independent prognostic biomarker of PC (p=0.046), which led to an obviously shorter 5-year overall survival (OS) compared to those patients with low UCA1 expressions (p=0.018). Furthermore, we effectively down-regulated UCA1 mRNA expression by transfecting RNA interfere fragments into SW-1990 cells, and our results in vitro indicated that down-regulation of UCA1 could effectively inhibit the cell proliferative activities, induce apoptotic rate and cause cell cycle arrest in PC cells (p<0.05). Meanwhile, UCA1 expression negative-correlated with p27 in PC tissues (r²=0.46, p<0.01), and knockdown of p27 partly abrogated the cell proliferative activities caused by UCA1 (p<0.05). Our results raised the possibility of using UCA1 as a potential prognostic biomarker and therapy target of PC, and down-regulation of UCA1 might be considered to be a novel molecular treatment strategy for patients with PC.

Upregulation of long non-coding RNA HIF 1α-anti-sense 1 induced by transforming growth factor-β-mediated targeting of sirtuin 1 promotes osteoblastic differentiation of human bone marrow stromal cells

The present study aimed to investigate the regulatory mechanism of long non-coding RNA hypoxia-inducible factor 1α-anti-sense 1 (lncRNA HIF1α-AS1) in osteoblast differentiation as well as its targeting by sirtuin 1 (SIRT1), which may be inhibited by transforming growth factor (TGF)-β in bone marrow stromal cells (BMSCs). Real-time polymerase chain reaction (PCR), western blot analysis, lncRNA PCR arrays and chromatin immunoprecipitation were performed in order to examine the interference of SIRT1 expression by TGF-β, the effects of SIRT1 overexpression on lncRNA HIF1α-AS1 and the regulation of the expression of homeobox (HOX)D10, which promotes BMSC differentiation, by lncRNA HIF1α-AS1. The results showed that TGF-β interfered with SIRT1 expression. Furthermore, lncRNA HIF1α-AS1 was significantly downregulated following overexpression of SIRT1. In addition, low expression of HIF1α-AS1 was sufficient to block the expression of HOXD10. The present study further demonstrated that downregulation of HOXD10 by HIF1α-AS1 interfered with acetylation, and subsequently resulted in the inhibition of osteoblast differentiation. These results suggested that HIF1α-AS1 is an essential mediator of osteoblast differentiation, and may thus represent a gene-therapeutic agent for the treatment of human bone diseases.

Long non-coding RNA: A new paradigm for lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Recent advances in whole genome transcriptome analysis have enabled the identification of numerous members of a novel class of non-coding RNAs, i.e., long non-coding RNAs (lncRNAs), which play important roles in a wide range of biological processes and whose deregulation causes human disease, including cancer. Herein we provide a comprehensive survey of lncRNAs associated with lung cancer, with particular focus on the functions that either facilitate or inhibit the progression of lung cancer and the pathways involved. Emerging data on the use of lncRNAs as biomarkers for the diagnosis and prognosis of cancer are also discussed. We cast this information within the wider perspective of lncRNA biogenesis and molecular functions in the cell. Relationships that exist between lncRNAs, genome-wide transcription, and lung cancer are discussed. Deepening our understanding on these processes is critical not only from a mechanistic standpoint, but also for the development of novel biomarkers and effective therapeutic targets for cancer patients.

Expression profiles and initial confirmation of long noncoding RNAs in Chinese patients with pulmonary adenocarcinoma

Background

The purpose of this study was to investigate differentially expressed long noncoding RNAs (lncRNAs) in pulmonary adenocarcinoma tissue and adjacent noncancerous tissue from Chinese patients using lncRNA expression microarray and preliminary analysis.

Methods

RNA extracted from three paired pulmonary adenocarcinoma tissue and adjacent noncancerous tissue specimens was used to synthesize double-stranded complementary DNA after labeling and hybridization. The complementary DNA was labeled and hybridized to the lncRNA expression microarray, and array data were analyzed for hierarchical clustering. Gene coexpression networks were constructed to identify interactions among genes. To validate the microarray findings, we measured the relative expression levels of four random differentially expressed lncRNAs in the same tissue used for microarray using real-time quantitative polymerase chain reaction. The expression level of one lncRNA, AK124939, in the paired pulmonary adenocarcinoma/adjacent noncancerous tissue of another 30 patients was measured using real-time quantitative polymerase chain reaction. The experimental data were further analyzed and compared with clinical features.

Results

Of 39,000 lncRNAs investigated, 704 were differentially expressed in pulmonary adenocarcinoma tissue; 385 were upregulated and 319 were downregulated compared with those in the adjacent noncancerous tissue (fold change ≥2 and ≤−2, P<0.05). AK124939 expression levels in poorly differentiated adenocarcinoma tissue were lower than those found in well to moderately differentiated adenocarcinoma tissue (P=0.05).

Conclusion

There are significant differences in the lncRNA expression profiles in Chinese patients with pulmonary adenocarcinoma. LncRNAs such as AK124939 may be anticancer factors related to the progression of pulmonary adenocarcinoma.