Intergenic Non-coding RNAs Research Articles

Non-Invasive Genomic Profiling in Pediatric Patients

Background:Pigmented lesions with clinical features suspicious for melanoma are not uncommon in pediatric patients. Evaluation of these lesions is complicated by the low prevalence of pediatric melanoma and challenges associated with performing biopsies in children. The DermTech Melanoma Test (‘the test’) is a non-invasive genomic test designed to rule out melanoma. It consists of the Pigmented Lesion Assay (PLA), which detects RNA gene expression of long intergenic non-coding RNA 00518 (LINC00518, or LINC) and preferentially expressed antigen in melanoma (PRAME), and an add-on assay for DNA promoter mutations in telomerase reverse transcriptase (TERT), which is performed if ordered and if sufficient genomic material is available. Patients younger than 18 years were not included in initial validation studies. In this analysis, we sought to compare genomic biomarker results between uncertain pigmented lesions from adult and pediatric patients.
 Methods:De-identified samples submitted to the clinical lab for the test from May through October 2022 were used for this analysis. Genomic results were available for 36,377 samples. The anatomic locations of the lesions were categorized as head/neck, trunk, or extremities and compared between adult and pediatric patients. Positivity rates for the PLA (and each individual marker) and the TERT add-on assay were calculated for adults and patients younger than 18 years of age.
 Results:The PLA was performed on 34,050 skin samples from adults and 2,327 samples from pediatric patients. There were no differences between adults and pediatric patients in anatomic location of the lesions tested. The proportion of PLA-positive samples was similar between adult (7.0%, n=2,393) and pediatric (8.0%, n=187) patients. Rates of biomarkers detected among PLA-positive adult and pediatric patient samples, respectively, were as follows: LINC only (31.4% vs 69.5%), PRAME only (45.5% vs 14.4%), LINC and PRAME (23.0% vs 16.0%). The TERT add-on assay was performed in 11,084 samples from adults and 613 samples from pediatric patients. Of these, TERT was positive in 830 (7.5%) adult and 3 (0.5%) pediatric patient samples.
 Conclusions:This analysis provides new information about genomic profiling of uncertain pigmented lesions from pediatric patients. While overall PLA positivity rates were similar across adult and pediatric samples, the proportion positive only for LINC was more than two times higher in pediatric samples. Additionally, TERT promoter mutations were rarely detected in pediatric samples. Further investigation of the significance of LINC, PRAME, and TERT abnormalities in lesions from pediatric patients is ongoing.

Genomic Profiling of Lentigo Maligna within an Interim Registry Analysis​

Background: Pigmented lesion analysis remains a challenging aspect of dermatology. The DermTech Melanoma Test (‘the test’) is a non-invasive genomic test designed to rule-out melanoma. It consists of the pigmented lesion assay, which detects RNA products of Long Intergenic Non-Coding RNA 00518 (LINC00518) and Preferentially Expressed Antigen in Melanoma (PRAME), and an add-on assay for DNA promoter mutations in telomerase reverse transcriptase (TERT). In previous studies, the test was found to have a negative predictive value ≥99%. This interim analysis of a registry study examines the genomic patterns of the Lentigo Maligna (LM) subtype of melanoma. Methods: Between April 2021 and March 2022, multiple geographically diverse sites throughout the US submitted data to a registry to assess real-world use of the test. Approximately 8,000 clinically atypical lesions were tested. After receiving the test result, providers followed their clinical judgement for biopsy decision. Histopathologic diagnoses for biopsied lesions were correlated with test results and all melanomas were sorted into LM subtype vs non-LM subtype. In addition, lesions that were noted to be on sun exposed skin and/or noted to have solar elastosis and called atypical melanocytic hyperplasia were included. Results: At the 1-year mark of the registry, there were roughly 8000 unique entries. Of those, 1003 expressed one or more genomic markers from the DMT and had records available, and 134 (13.2%) were found to be melanoma or melanoma in-situ. More than a third (n=46, 34.3%) of the melanomas were of the Lentigo Maligna sub-type, with 7 of those being Lentigo Maligna Melanoma (LMM). Seven additional lesions were called atypical junctional melanocytic hyperplasia (AJMH) on sun-damaged skin. This group of 53 LM, LMM, and AJMH lesions were all evaluated for correlations to the DMT markers. LINC was the most commonly expressed genomic marker (n=45, 84.9%), with PRAME (n=36, 67.9%) and TERT (n=24, 45.3%) following. Most invasive tumors (LMM) expressed all three markers (n=4) and all 7 expressed LINC. Conclusion: While the original validation study included the LM subtype, this interim registry analysis demonstrates real-world use of the DMT in assessing pigmented macules concerning for LM. Over 1/3 of the melanomas reported in the registry were LM subtypes. LINC had a higher correlation with the lentigo maligna subtype of melanoma and was present in all invasive tumors. While AJMH is considered borderline, it may be worthwhile in the clinical context to group AJMH lesions with LM due to similarities in treatment.

Concordance of Preferentially Expressed Antigen in Melanoma by Non-Invasively Collected Polymerase Chain Reaction and Immunohistochemistry on Paraffin Embedded Tissue

Background: ​
 Pigmented lesion evaluation remains a challenging aspect of dermatology. The DermTech Melanoma Test (DMT) is a non-invasive gene-expression test designed to rule-out melanoma. It consists of the pigmented lesion assay, which detects RNA products of Long Intergenic Non-Coding RNA 00518 (LINC00518) and Preferentially Expressed Antigen in Melanoma (PRAME), and an add-on assay for DNA promoter mutations in telomerase reverse transcriptase (TERT). This registry study examines the concordance of PRAME detection by polymerase chain reaction (PCR) in samples obtained non-invasively prior to biopsy and PRAME detection by immunohistochemistry (IHC) on the same lesions after biopsy.​
 Methods: ​
 Between April 2021 and March 2022, multiple geographically diverse sites throughout the US submitted data to a registry to assess real-world use of the DMT. Approximately 8,000 clinically atypical lesions were tested. After receiving the test result, providers followed their clinical judgement for biopsy decision. When lesions expressed genomic markers (LINC, PRAME, and/or TERT) and were biopsied, pathology reports were also submitted to the registry. The presence or absence of PRAME by immunohistochemistry (IHC) was reviewed and compared to the detection of PRAME by PCR from the DMT on the same lesion.​
 Results: ​
 At the 1-year mark of the registry, there were roughly 8,000 unique entries. Of those, 1,021 (12.8%) were positive for one or more of the DMT genomic markers. One thousand three lesions (98.2%) had records available. Pathologists used PRAME IHC for 102 lesions (10.2%). Of those, 40 (39.2%) were positive by IHC, and 62 (60.8%) were negative by IHC. PRAME positivity by PCR correlated with PRAME positivity by IHC in 35 of 40 lesions (87.5%). Conversely, PRAME was detected using PCR in 28 of 62 lesions (45.2%) where it was not detected using IHC. ​
 Conclusions: ​
 The higher sensitivity of PCR compared to IHC may explain the higher concordance when PRAME is positive by IHC than when it is negative by IHC. In this data set, when PRAME is positive by IHC it is usually also positive by PCR. When PRAME is negative by IHC, it can still be detected by PCR in a substantial percentage of cases. The increased sensitivity of PCR is likely due to several factors, including its detection of the PRAME mRNA and sampling of the entire lesion. As such, PRAME PCR status may aid pathologists in understanding the risk of melanoma even when IHC is negative. Further research is warranted to understand the clinical implications of PRAME PCR versus IHC positivity. ​

Downregulation of MALAT1 is a hallmark of tissue and peripheral proliferative T cells in COVID-19.

T cells play key protective but also pathogenic roles in COVID-19. We studied the expression of long non-coding RNAs (lncRNAs) in COVID-19 T-cell transcriptomes by integrating previously published single-cell RNA sequencing datasets. The long intergenic non-coding RNA MALAT1 was the most highly transcribed lncRNA in T cells, with Th1 cells demonstrating the lowest and CD8+ resident memory cells the highest MALAT1 expression, amongst CD4+ and CD8+ T-cells populations, respectively. We then identified gene signatures that covaried with MALAT1 in single T cells. A significantly higher number of transcripts correlated negatively with MALAT1 than those that correlated. Enriched functional annotations of the MALAT1- anti-correlating gene signature included processes associated with T-cell activation such as cell division, oxidative phosphorylation, and response to cytokine. The MALAT1 anti-correlating gene signature shared by both CD4+ and CD8+ T-cells marked dividing T cells in both the lung and blood of COVID-19 patients. Focussing on the tissue, we used an independent patient cohort of post-mortem COVID-19 lung samples and demonstrated that MALAT1 suppression was indeed a marker of MKI67+ proliferating CD8+ T cells. Our results reveal MALAT1 suppression and its associated gene signature are a hallmark of human proliferating T cells.

LINC00511 promotes melanoma progression by targeting miR-610/NUCB2.

Long intergenic noncoding RNA 00511 (LINC00511) predicts poor prognosis in various malignancies and functions as an oncogene in distinct malignant tumors. The role of LINC00511 in melanoma progression was assessed. In our research, expression of LINC00511 in melanoma cells was detected by quantitative reverse transcription PCR. Colony formation and CCK8 assays were used to detect cell proliferation. Cell metastasis was evaluated by transwell and wound healing assays. Downstream target of LINC00511 was investigated by luciferase activity assay. As a results, LINC00511 was elevated in melanoma cells and tissues. Loss of LINC00511 decreased cell viability, reduced proliferation, invasion, and migration of melanoma. miR-610 was target of LINC00511, and miR-610 binds to 3'UTR of nucleobindin-2 (NUCB2). Inhibition of miR-610 attenuated LINC00511 deficiency-induced decrease of NUCB2 in melanoma cells. Loss of miR-610 weakened LINC00511 deficiency-induced decrease of cell viability, proliferation, invasion, and migration of melanoma. In conclusion, silence of LINC00511 reduced cell proliferation and metastasis of melanoma through down-regulation of miR-610-mediated NUCB2.

LINC00632 relates to milder Th1/Th2 imbalance, attenuated nasal symptoms, and better response to therapy in allergic rhinitis patients.

Long intergenic noncoding RNA 00632 (LINC00632) regulates nasal inflammation and CD4+ T cell differentiation into T helper (Th) 2 cells in allergic rhinitis (AR). This study aimed to explore the relationship between LINC00632 and Th1/Th2 balance, and the clinical value of LINC00632 in AR patients. In total, 120 AR patients, 20 non-atopic obstructive snoring patients as disease controls (DCs), and 20 healthy controls (HCs) were recruited. Their LINC00632 expressions in peripheral blood mononuclear cells were detected by RT-qPCR. LINC00632 expression was declined in AR patients compared with DCs and HCs (both P ˂ 0.001). Moreover, LINC00632 could distinguish AR patients from DCs with an area under curve (AUC) of 0.795 (95% confidence interval [CI]: 0.701-0.889), and from HCs with an AUC of 0.895 (95%CI: 0.831-0.960). LINC00632 was positively related to Th1 cells (P = 0.037) and Th1/Th2 axis (P ˂ 0.001) in AR patients. In addition, LINC00632 was inversely associated with Th2 cells (P ˂ 0.001) and interleukin (IL)-4 (P = 0.010) in AR patients. Besides, LINC00632 was negatively related to rhinorrhea score (P = 0.019), itching score (P = 0.008), sneezing score (P = 0.004), and total nasal symptom score (TNSS) (P ˂ 0.001), but no correlation between LINC00632 and congestion score was observed (P = 0.093). During treatment, LINC00632 was elevated, while TNSS score was reduced (both P ˂ 0.001). Furthermore, LINC00632 increment was associated with the reduction of TNSS score during the therapy (P = 0.005). LINC00632 relates to milder Th1/Th2 imbalance, attenuated nasal symptoms, and better response during 4-week therapy in AR patients.

A comprehensive review of the role of LINC00462 in human disorders.

LINC00462; a long intergenic non-coding RNA located on chromosome chr13:48,576,973-48,590,587 is a member of long non-coding RNA (lncRNA) that is participated in different human disorders such as pancreatic cancer and hepatocellular carcinoma. LINC00462 can act as competing endogenous RNAs (ceRNAs), to sponge different MicroRNAs (miRNAs) such as miR-665. Dysregulation of LINC00462 can promote cancer development, progression, and metastasis. LINC00462 can also bind directly with genes and proteins to regulate different pathways, including STAT2/3 and PI3K/AKT pathways to affected tumor progression. In addition, aberrant LINC00462 levels can be important cancer-specific prognostic and diagnostic markers. In this review, we summarize the most recent studies on the role of LINC00462 in different disorders and demonstrated the role of LINC00462 in tumorigenesis.

Rs205764 and rs547311 in linc00513 may influence treatment responses in multiple sclerosis patients: A pharmacogenomics Egyptian study.

Multiple sclerosis (MS) is characterized by a complex etiology that is reflected in the lack of consistently predictable treatment responses across patients of seemingly similar characteristics. Approaches to demystify the underlying predictors of aberrant treatment responses have made use of genome-wide association studies (GWAS), with imminent progress made in identifying single nucleotide polymorphisms (SNPs) associated with MS risk, disease progression, and treatment response. Ultimately, such pharmacogenomic studies aim to utilize the approach of personalized medicine to maximize patient benefit and minimize rate of disease progression. Very limited research is available around the long intergenic non-coding RNA (linc)00513, recently being reported as a novel positive regulator of the type-1 interferon (IFN) pathway, following its overexpression in the presence of two polymorphisms: rs205764 and rs547311 in the promoter region of this gene. We attempt to provide data on the prevalence of genetic variations at rs205764 and rs547311 in Egyptian MS patients, and correlate these polymorphisms with the patients' responses to disease-modifying treatments. Genomic DNA from 144 RRMS patients was isolated and analyzed for genotypes at the positions of interest on linc00513 using RT-qPCR. Genotype groups were compared with regards to their response to treatment; additional secondary clinical parameters including the estimated disability status score (EDSS), and onset of the disease were examined in relation to these polymorphisms. Polymorphisms at rs205764 were associated with a significantly higher response to fingolimod and a significantly lower response to dimethylfumarate. Moreover, the average EDSS of patients carrying polymorphisms at rs547311 was significantly higher, whereas no correlation appeared to exist with the onset of MS. Understanding the complex interplay of factors influencing treatment response is pivotal in MS. One of the factors contributing to a patient's response to treatment, as well as disease disability, may be polymorphisms on non-coding genetic material, such as rs205764 and rs547311 on linc00513. Through this work, we propose that genetic polymorphisms may partially drive disease disability and inconsistent responses to treatment in MS; we also aim to draw attention towards genetic approaches, such as screening for specific polymorphisms, to possibly direct treatment choices in such a complex disease.

Differential Expression of lincRNA-ROR Spliced Transcript Variants in Breast Cancer.

We investigated the expression pattern of a human stem cell-specific, large intergenic noncoding RNA (lincRNA) regulator of reprogramming (lincRNA-ROR) and its spliced transcript variants in breast tumors. Breast cancer is the leading cause of cancer mortality in women; therefore, finding a reliable diagnostic tumor marker, based on the molecular profile of tumor cells, is warranted. qRT-PCR was used to investigate the expression alteration of a specific stem cell-related lincRNA and its spliced transcript variants in breast tumors which provided by the Iran National Tumor Bank (2014-2016). Suitability of lincRNA-ROR and expression alterations of its spliced transcript variants as breast tumor biomarkers were examined by ROC curve analysis. Expression was significantly upregulated in lincRNA-ROR variants 1 (NR-048536) and 4 (AB844432) and downregulated in variant 3 (AB844431), with expression levels failing to distinguish between breast tumor types, grades, and malignancy stages. Whereas ROC curve analysis gave good scores to the expressions of variants 1 (AUC=0.7675, P=0.003) and 3 (AUC=0.9383, P=0.00173), suggesting their suitability as potential breast tumor biomarkers, it gave an AUC score of 0.6033 for lincRNA-ROR spliced variant 4 (P=0.4118), denoting its unsuitability as a breast cancer biomarker. Aberrant expressions of lincRNA-ROR spliced transcript variants could serve as reliable biomarkers with potential usefulness in breast cancer diagnosis. However, further research should elucidate the role and tissue expression of lincRNA-ROR spliced transcript variants in various cancers.

Upregulation of long intergenic non-coding RNA LINC00326 inhibits non-small cell lung carcinoma progression by blocking Wnt/β-catenin pathway through modulating the miR-657/dickkopf WNT signaling pathway inhibitor 2 axis

BackgroundLong intergenic non-coding RNA 326 (LINC00326) modulates hepatocarcinogenic lipid metabolism. However, the ability of LINC00326 to modulate the highly aggressive non-small cell lung carcinoma (NSCLC) is unknown. Here, LINC00326 in NSCLC was investigated, together with its effects on tumor malignancy and the underlying mechanisms of action.MethodsLINC00326 levels in tumor tissues and cell lines were measured by Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and RNA fluorescence in situ hybridization (FISH). Proliferation and apoptosis were assessed in cell lines by Cell Counting Kit-8 (CCK-8), EdU staining assays and flow cytometry, respectively, and tumor growth was measured in mouse models. Possible microRNA targets of LINC00326 were predicted by bioinformatics and verified by RNA pull-down and immunoprecipitation and luciferase reporter assays. Western blotting was used to evaluate the expression of Wnt/β-catenin-associated proteins.Results LINC00326 was downregulated in tumor tissues and cell lines. Knockdown of LINC00326 stimulated NSCLC cell proliferation and suppressed apoptosis in vitro, as well as enhancing xenograft tumor growth. LINC00326 sponged miR-657, and dickkopf WNT signaling pathway inhibitor 2 (DKK2) was found to be directly targeted by miR-657, with LINC00326 positively regulating its expression through sponging miR-657. The actions of LINC00326 knockdown on proliferation and apoptosis were reversed by stimulation of the miR-657/DKK2 axis. Furthermore, overexpression of miR-657 mitigated DKK2 inhibition on Wnt/β-catenin signaling.ConclusionsLINC00326/miR-657/DKK2 axis signaling blocked tumor-associated functions in NSCLC cells through the targeting Wnt/β-catenin pathway. This suggests that this pathway could be a target for NSCLC treatment.

Ataxin-1 controls the expression of specific noncoding RNAs in B cells upon autoimmune demyelination.

B cells play a key mechanistic role in the pathogenesis of multiple sclerosis (MS), a chronic neurological disease of the central nervous system with an autoimmune etiology. B cells contribute to disease initiation and progression by acting as professional antigen-presenting cells as well as via secreting autoantibodies and proinflammatory cytokines. We have recently shown that the polyglutamine protein ataxin-1, which was first linked to the movement disorder spinocerebellar ataxia type 1, also acts as a master regulator of B-cell functions in the context of central nervous system autoimmunity. In fact, ataxin-1-deficient mice display an aggravated manifestation of the MS disease model experimental autoimmune encephalomyelitis along with aberrant B-cell functions. Consistent with this scenario, transcriptomic analysis of Atxn1-null Bcells highlighted distinct genetic signatures involved in cell activation, proliferation and antigen presentation. To further characterize the role of ataxin-1, we profiled the noncoding transcriptome controlled by ataxin-1 in the B-cell compartment upon an encephalitogenic challenge. We show that two specific classes of noncoding RNAs, namely, processed pseudogenes and intergenic long noncoding RNAs, are differentially regulated along disease. Furthermore, pathway and protein network analyses on their putative protein-coding gene targets found a significant enrichment in ontologies related to cell mitosis, together with molecular processes relevant to MS such as chitin metabolism. Altogether, these findings shed light on the possible contribution of noncoding RNAs to B-cell biology and MS pathogenesis, and further establish the immunomodulatory role of ataxin-1 in autoimmune demyelination.

The Diagnostic and Therapeutic Role of snoRNA and lincRNA in Bladder Cancer

Bladder cancer is one of the most common malignancies of the urinary tract and can be divided into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Although the means of diagnosis and treatment have continually improved in recent years, the recurrence rate of bladder cancer remains high, and patients with MIBC typically have an unfavourable prognosis and a low quality of life. Emerging evidence demonstrates that long noncoding RNAs play a crucial role in the carcinogenesis and progression of bladder cancer. Long intergenic noncoding RNAs (lincRNAs) are a subgroup of long noncoding RNAs (lncRNAs) that do not overlap protein-coding genes. The potential role of lincRNAs in the regulation of gene expression has been explored in depth in recent years. Small nucleolar RNAs (snoRNAs) are a class of noncoding RNAs (ncRNAs) that mainly exist in the nucleolus, are approximately 60-300 nucleotides in length, and are hosted inside the introns of genes. Small nucleolar RNA host genes (SNHGs) have been associated with the origin and development of bladder cancer. In this review, we aim to comprehensively summarize the biological functions of these molecules in bladder cancer.

Functional Relevance of the Long Intergenic Non-Coding RNA Regulator of Reprogramming (Linc-ROR) in Cancer Proliferation, Metastasis, and Drug Resistance.

Cancer is responsible for more than 10 million deaths every year. Metastasis and drug resistance lead to a poor survival rate and are a major therapeutic challenge. Substantial evidence demonstrates that an increasing number of long non-coding RNAs are dysregulated in cancer, including the long intergenic non-coding RNA, regulator of reprogramming (linc-ROR), which mostly exerts its role as an onco-lncRNA acting as a competing endogenous RNA that sequesters micro RNAs. Although the properties of linc-ROR in relation to some cancers have been reviewed in the past, active research appends evidence constantly to a better comprehension of the role of linc-ROR in different stages of cancer. Moreover, the molecular details and some recent papers have been omitted or partially reported, thus the importance of this review aimed to contribute to the up-to-date understanding of linc-ROR and its implication in cancer tumorigenesis, progression, metastasis, and chemoresistance. As the involvement of linc-ROR in cancer is elucidated, an improvement in diagnostic and prognostic tools could promote and advance in targeted and specific therapies in precision oncology.

Genome-wide analysis reveals the crucial role of lncRNAs in regulating the expression of genes controlling pollen development.

The genomic location and stage-specific expression pattern of many long non-coding RNAs reveal their critical role in regulating protein-coding genes crucial in pollen developmental progression and male germ line specification. Long non-coding RNAs (lncRNAs) are transcripts longer than 200bp with no apparent protein-coding potential. Multiple investigations have revealed high expression of lncRNAs in plant reproductive organs in a cell and tissue-specific manner. However, their potential role as essential regulators of molecular processes involved in sexual reproduction remains largely unexplored. We have used developing field mustard (Brassica rapa) pollen as a model system for investigating the potential role of lncRNAs in reproductive development. Reference-based transcriptome assembly performed to update the existing genome annotation identified novel expressed protein-coding genes and long non-coding RNAs (lncRNAs), including 4347 long intergenic non-coding RNAs (lincRNAs, 1058 expressed) and 2,045 lncRNAs overlapping protein-coding genes on the opposite strand (lncNATs, 780 expressed). The analysis of expression profiles reveals that lncRNAs are significant and stage-specific contributors to the gene expression profile of developing pollen. Gene co-expression networks accompanied by genome location analysis identified 38 cis-acting lincRNA, 31 cis-acting lncNAT, 7 trans-acting lincRNA and 14 trans-acting lncNAT to be substantially co-expressed with target protein-coding genes involved in biological processes regulating pollen development and male lineage specification. These findings provide a foundation for future research aiming at developing strategies to employ lncRNAs as regulatory tools for gene expression control during reproductive development.

Placental circadian lincRNAs and spontaneous preterm birth.

Long non-coding RNAs (lncRNAs) have a much higher cell- and/or tissue-specificity compared to mRNAs in most cases, making them excellent candidates for therapeutic applications to reduce off-target effects. Placental long non-coding RNAs have been investigated in the pathogenesis of preeclampsia (often causing preterm birth (PTB)), but less is known about their role in preterm birth. Preterm birth occurs in 11% of pregnancies and is the most common cause of death among infants in the world. We recently identified that genes that drive circadian rhythms in cells, termed molecular clock genes, are deregulated in maternal blood of women with spontaneous PTB (sPTB) and in the placenta of women with preeclampsia. Next, we focused on circadian genes-correlated long intergenic non-coding RNAs (lincRNAs, making up most of the long non-coding RNAs), designated as circadian lincRNAs, associated with sPTB. We compared the co-altered circadian transcripts-correlated lincRNAs expressed in placentas of sPTB and term births using two published independent RNAseq datasets (GSE73712 and GSE174415). Nine core clock genes were up- or downregulated in sPTB versus term birth, where the RORA transcript was the only gene downregulated in sPTB across both independent datasets. We found that five circadian lincRNAs (LINC00893, LINC00265, LINC01089, LINC00482, and LINC00649) were decreased in sPTB vs term births across both datasets (p ≤ .0222, FDR≤.1973) and were negatively correlated with the dataset-specific clock genes-based risk scores (correlation coefficient r = -.65 ∼ -.43, p ≤ .0365, FDR≤.0601). Gene set variation analysis revealed that 65 pathways were significantly enriched by these same five differentially expressed lincRNAs, of which over 85% of the pathways could be linked to immune/inflammation/oxidative stress and cell cycle/apoptosis/autophagy/cellular senescence. These findings may improve our understanding of the pathogenesis of spontaneous preterm birth and provide novel insights into the development of potentially more effective and specific therapeutic targets against sPTB.

LINC00669 promotes lung adenocarcinoma growth by stimulating the Wnt/β-catenin signaling pathway.

Lung cancer poses severe threats to human health. It is indispensable to discover more druggable molecular targets. We identified a novel dysregulated long non-coding RNA (lncRNA), LINC00669, in lung adenocarcinoma (LUAD) by analyzing the TCGA and GEO databases. Pan-cancer analysis indicated significantly upregulated LINC00669 across 33 cancer types. GSEA revealed a tight association of LINC00669 with the cell cycle. We next attempted to improve the prognostic accuracy of this lncRNA by establishing a risk signature in reliance on cell cycle genes associated with LINC00669. The resulting risk score combined with LINC00669 and stage showed an AUC of 0.746. The risk score significantly stratified LUAD patients into low- and high-risk subgroups, independently predicting prognosis. Its performance was verified by nomogram (C-index=0.736) and decision curve analysis. Gene set variation analysis disclosed the two groups' molecular characteristics. We also evaluated the tumor immune microenvironment by dissecting 28 infiltrated immune cells, 47 immune checkpoint gene expressions, and immunophenoscore within the two subgroups. Furthermore, the risk signature could predict sensitivity to immune checkpoint inhibitors and other anticancer therapies. Eventually, in vitro and in vivo experiments were conducted to validate LINC00669's function using qRT-PCR, CCK8, flow cytometry, western blot, and immunofluorescence staining. The gain- and loss-of-function study substantiated LINC00669's oncogenic effects, which stimulated non-small cell lung cancer cell proliferation but reduced apoptosis via activating the Wnt/β-catenin pathway. Its oncogenic potentials were validated in the xenograft mouse model. Overall, we identified a novel oncogenic large intergenic non-coding RNA (lincRNA), LINC00669. The resulting signature may facilitate predicting prognosis and therapy responses in LUAD.

Linc279227 contributes to mitochondrial dysfunction in high glucose-treated mouse renal tubular epithelial cells

BackgroundThe aberrant expression of long noncoding RNAs (lncRNAs) has been associated with diabetic nephropathy (DN), a major complication of diabetes mellitus (DM). This study investigated the differential expression of lncRNAs in DM without renal damage and DM with renal damage, known as DN, and elucidated the functions of a pathogenic lncRNA. MethodsHigh-throughput sequencing was performed on the kidneys of male db/db mice with kidney injury, db/db mice without kidney involvement and db/m control littermates. Linc279227 expression was confirmed by RT‒qPCR and fluorescence in situ hybridization. The effects of linc279227 on high glucose (HG)-treated renal tubular epithelial cells (RTECs) were evaluated by autophagy flux monitoring, Western blot determination and mitochondrial morphological detection. ResultsWith high-throughput sequencing, we identified a 1024 nt long intergenic noncoding RNA, TCONS_00279227 (linc279227), whose expression was markedly increased in the kidneys of db/db mice with kidney injury compared to db/db mice without kidney injury and db/m control littermates. Fluorescence in situ hybridization confirmed that linc279227 was mainly located in the renal tubules of mice with DN. In vitro, linc279227 expression was found to be significantly increased in RTECs treated with high glucose (HG) for 48 h. Silencing linc279227 markedly restored the levels of autophagy-/mitophagy-associated proteins in HG-stimulated RTECs. Furthermore, silencing linc279227 reduced phosphorylated Drp1 expression and increased Mfn2 expression in RTECs exposed to HG. ConclusionOur data suggest that linc279227 plays an important role in mitochondrial dysfunction in HG-treated RTECs and that silencing linc279227 rescues RTECs exposed to HG.

ADAR RNA editing on antisense RNAs results in apparent U-to-C base changes on overlapping sense transcripts.

Despite hundreds of RNA modifications described to date, only RNA editing results in a change in the nucleotide sequence of RNA molecules compared to the genome. In mammals, two kinds of RNA editing have been described so far, adenosine to inosine (A-to-I) and cytidine to uridine (C-to-U) editing. Recent improvements in RNA sequencing technologies have led to the discovery of a continuously growing number of editing sites. These methods are powerful but not error-free, making routine validation of newly-described editing sites necessary. During one of these validations on DDX58 mRNA, along with A-to-I RNA editing sites, we encountered putative U-to-C editing. These U-to-C edits were present in several cell lines and appeared regulated in response to specific environmental stimuli. The same findings were also observed for the human long intergenic non-coding RNA p21 (hLincRNA-p21). A more in-depth analysis revealed that putative U-to-C edits result from A-to-I editing on overlapping antisense RNAs that are transcribed from the same loci. Such editing events, occurring on overlapping genes transcribed in opposite directions, have recently been demonstrated to be immunogenic and have been linked with autoimmune and immune-related diseases. Our findings, also confirmed by deep transcriptome data, demonstrate that such loci can be recognized simply through the presence of A-to-I and U-to-C mismatches within the same locus, reflective A-to-I editing both in the sense-oriented transcript and in the cis-natural antisense transcript (cis-NAT), implying that such clusters could be a mark of functionally relevant ADAR1 editing events.

LINC00963 promotes the malignancy and metastasis of lung adenocarcinoma by stabilizing Zeb1 and exosomes-induced M2 macrophage polarization

BackgroundLong intergenic non-coding RNA 00963 (LINC00963) is an oncogenic lncRNA in human cancers. However, little is known on how it impacts the pathogenesis of lung adenocarcinoma (LUAD).MethodsBiological effects on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) were examined by CCK-8, colony formation, EdU incorporation, transwell, and immunofluorescence assays, respectively. Macrophage polarization was evaluated by flow cytometry. Ubiquitination of Zeb1 was examined by co-immunoprecipitation. The location of LINC00963 in LUAD tissues and cell lines was tested by FISH assay. The LINC00963/HNRNPA2B1/Siah1 mRNA complex interaction was verified using RNA pull-down and immunoprecipitation assays. The exact roles of LINC00963 were further validated in metastasis and xenograft models.ResultsHigher LINC00963 expression in LUAD patients positively correlated with shorter overall survival, higher stages, and metastasis. LINC00963 mainly localized in the cytoplasm and aggravated malignant phenotypes of LUAD cells in vitro and metastasis in vivo. Mechanistically, LINC00963 directly interacted HNRNPA2B1 protein to trigger the degradation of Siah1 mRNA, which inhibited the ubiquitination and degradation of Zeb1. Moreover, exosomal LINC00963 derived from LUAD cells induced M2 macrophage polarization and promoted LUAD growth and metastasis.ConclusionBy stabilizing Zeb1 in cancer cells and delivering exosomes to induce M2 macrophage polarization, LINC00963 promoted the malignancy and metastasis of LUAD. Targeting LINC00963 may become a valuable therapeutic target for LUAD.

Protein-Coding Region Derived Small RNA in Exosomes from Influenza A Virus-Infected Cells.

Exosomes may function as multifactorial mediators of cell-to-cell communication, playing crucial roles in both physiological and pathological processes. Exosomes released from virus-infected cells may contain RNA and proteins facilitating infection spread. The purpose of our study was to analyze how the small RNA content of exosomes is affected by infection with the influenza A virus (IAV). Exosomes were isolated by ultracentrifugation after hemadsorption of virions and their small RNA content was identified using high-throughput sequencing. As compared to mock-infected controls, 856 RNA transcripts were significantly differentially expressed in exosomes from IAV-infected cells, including fragments of 458 protein-coding (pcRNA), 336 small, 28 long intergenic non-coding RNA transcripts, and 33 pseudogene transcripts. Upregulated pcRNA species corresponded mainly to proteins associated with translation and antiviral response, and the most upregulated among them were RSAD2, CCDC141 and IFIT2. Downregulated pcRNA species corresponded to proteins associated with the cell cycle and DNA packaging. Analysis of differentially expressed pseudogenes showed that in most cases, an increase in the transcription level of pseudogenes was correlated with an increase in their parental genes. Although the role of exosome RNA in IAV infection remains undefined, the biological processes identified based on the corresponding proteins may indicate the roles of some of its parts in IAV replication.