PU.1 controls the expression of long noncoding RNA HOTAIRM1 during granulocytic differentiation

Biological functions and affected signaling pathways by Long Non-Coding RNAs in the immune system

Recently, the various regulative functions of long non-coding RNAs (LncRNAs) have been well determined. Recently, the vital role of LncRNAs as gene regulators has been identified in the immune system, especially in the inflammatory response. All cells of the immune system are governed by a complex and ever-changing gene expression program that is regulated through both transcriptional and post-transcriptional processes. LncRNAs regulate gene expression within the cell nucleus by influencing transcription or through post-transcriptional processes that affect the splicing, stability, or translation of messenger RNAs (mRNAs). Recent studies in immunology have revealed substantial alterations in the expression of lncRNAs during the activation of the innate immune system as well as the development, differentiation, and activation of T cells. These lncRNAs regulate key aspects of immune function, including the manufacturing of inflammatory molecules, cellular distinction, and cell movement. They do this by modulating protein-protein interactions or through base pairing with RNA and DNA. Here we review the current understanding of the mechanism of action of lncRNAs as novel immune-related regulators and their impact on physiological and pathological processes related to the immune system, including autoimmune diseases. We also highlight the emerging pattern of gene expression control in important research areas at the intersection between immunology and lncRNA biology.

Clinical relevance of long non-coding RNA in acute myeloid leukemia: A systematic review with meta-analysis

BACKGROUND

Long noncoding RNAs (lncRNAs) may function as prognostic biomarkers in acute myeloid leukaemia (AML). However, it is still unknown exactly how significant lncRNAs are for the prognosis of AML. With a focus on their prognostic and therapeutic potential, the study aimed to provide a comprehensive review of the literature regarding the role of lncRNAs in AML.

METHOD

Pub Med, The Cochrane Library, Embase, Science Direct, Web of science, Scopus, and Google scholar were searched until November, 2023. Original publications of any type exploring the prognostic and therapeutic potential of lncRNAs in AML patients were included. Heterogeneity and publication bias were examined using the I2 test and a funnel plot, respectively. To quantify the relationship between various lncRNA expression in AML patient survival, odds ratios (ORs) or hazards ratios (HRs) with 95 % confidence intervals (CIs) were pooled. Quality of studies was assessed using the Critical Appraisal Checklists for Studies created by the Joanna Briggs Institute (JBI).

RESULTS

Twenty-seven studies including 5665 subjects were selected for the final analysis. In patients with AML, abnormal lncRNA expression has been associated with significant worse overall survival (pooled HR = 2.05, 95 % CI = 1.79-2.30, P <0.001), shorter disease-free survival (pooled HR = 2.17, 95 % CI = 1.13-3.22, P< 0.001), and lower complete remission rate (pooled HR = 0.27, 95 % CI = 0.11-0.43, P< 0.001). Poor prognoses have been attributed to increased expression of HOX transcript antisense intergenic RNA (HOTAIR), Promoter Of CDKN1A Antisense DNA Damage Activated RNA (PANDAR), Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1), RP11-222K16.2, Taurine Upregulated Gene 1 (TUG1), Small Nucleolar RNA Host Gene 5 (SNHG5), Growth Arrest Specific 5 (GAS5), and H19 and decreased expression of IGF1R Antisense Imprinted Non-Protein Coding RNA (IRAIN).

CONCLUSION

The prognoses of AML patients are significantly associated with abnormally expressed lncRNAs, which may be used as prognostic indicators for predicting the patient outcomes.

Roles of non-coding RNA in megakaryocytopoiesis and thrombopoiesis: new target therapies in ITP

Noncoding RNAs (ncRNAs) are a group of RNA molecules that cannot encode proteins, and a better understanding of the complex interaction networks coordinated by ncRNAs will provide a theoretical basis for the development of therapeutics targeting the regulatory effects of ncRNAs. Platelets are produced upon the differentiation of hematopoietic stem cells into megakaryocytes, 10¹¹ per day, and are renewed every 8-9 days. The process of thrombopoiesis is affected by multiple factors, in which ncRNAs also exert a significant regulatory role. This article reviewed the regulatory roles of ncRNAs, mainly microRNAs (miRNAs), circRNAs (circular RNAs), and long non-coding RNAs (lncRNAs), in thrombopoiesis in recent years as well as their roles in primary immune thrombocytopenia (ITP).

The non-coding competing endogenous RNAs in acute myeloid leukemia: biological and clinical implications

Acute myeloid leukemia (AML) is a hematologic carcinoma that has seen a considerable improvement in patient prognosis because of genetic diagnostics and molecularly-targeted therapies. Nevertheless, recurrence and drug resistance remain significant obstacles to leukemia treatment. It is critical to investigate the underlying molecular mechanisms and find solutions. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), circular RNAs, long non-coding RNAs, and pseudogenes, have been found to be crucial components in driving cancer. The competing endogenous RNA (ceRNA) mechanism has expanded the complexity of miRNA-mediated gene regulation. A great deal of literature has shown that ncRNAs are essential to the biological functions of the ceRNA network (ceRNET). NcRNAs can compete for the same miRNA response elements to influence miRNA-target RNA interactions. Recent evidence suggests that ceRNA might be a potential biomarker and therapeutic strategy. So far, however, there have been no comprehensive studies on ceRNET about AML. What is not yet clear is the clinical application of ceRNA in AML. This study attempts to summarize the development of research on the related ceRNAs in AML and the roles of ncRNAs in ceRNET. We also briefly describe the mechanisms of ceRNA and ceRNET. What's more significant is that we explore the clinical value of ceRNAs to provide accurate diagnostic and prognostic biomarkers as well as therapeutic targets. Finally, limitations and prospects are considered.

Analyses of lncRNAs, circRNAs, and the Interactions between ncRNAs and mRNAs in Goat Submandibular Glands Reveal Their Potential Function in Immune Regulation

As part of one of the main ruminants, goat salivary glands hardly secrete digestive enzymes, but play an important role in immunity. The immune function of goat salivary glands significantly changes with age, while the expression profile and specific function of non-coding RNA during this process are unknown. In this study, transcriptome sequencing was performed on submandibular gland (SMG) tissues of 1-month-old, 12-month-old, and 24-month-old goats, revealing the expression patterns of lncRNA and circRNA at different ages. A total of 369 lncRNAs and 1699 circRNAs were found to be differentially expressed. Functional enrichment analyses showed that the lncRNA regulated target mRNAs and circRNA host genes were significantly enriched in immune-related GO terms and pathways. CeRNA network analysis showed that the key differentially expressed circRNAs and lncRNAs mainly regulate the key immune-related genes ITGB2, LCP2, PTPRC, SYK, and ZAP70 through competitive binding with miR-141-x, miR-29-y, and chi-miR-29b-3p, thereby affecting the natural killer cell-mediated cytotoxicity pathway, the T cell receptor signaling pathway, and other immune-related pathways. It should be noted that the expression of key circRNAs, lncRNAs, and key immune-related genes in goat SMGs decreased significantly with the growth of the goat. This is the first reporting of lncRNAs, circRNAs, and ceRNA network regulation in goat SMGs. Our study contributes to the knowledge of changes in the expression of non-coding RNAs during SMG development in goats and provides new insights into the relationship between non-coding RNAs and salivary gland immune function in goats.

The potential role of serum expression profile of long non coding RNAs, Cox2 and HOTAIR as novel diagnostic biomarkers in systemic lupus erythematosus

BACKGROUND

The role of the long non-coding RNAs (lncRNAs) in the pathogenesis of systemic lupus erythematosus (SLE) is mostly unknown, despite increasing evidence that lncRNAs extensively participate in physiological and pathological conditions.

AIM

To detect the level of lncRNA-Cox2, HOTAIR, IL-6, and MMP-9 in the serum of SLE patients and to correlate these levels with disease activity and patients' clinical and laboratory data to evaluate the value of these biomarkers for SLE diagnosis and assessment of disease activity.

METHODS

Blood samples from 58 SLE patients, and 60 healthy controls (HCs) were used for detection of lncRNAs-Cox2 and HOTAIR expression levels by real-time polymerase chain reaction. Both IL-6 and MMP-9 serum levels were assayed by enzyme-linked immunosorbent assay. Lupus activity was assessed with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI).

RESULTS

The serum expression levels of lncRNA-Cox2 and HOTAIR were significantly up-regulated in SLE patients vs HCs (fold change [median (IQR) was 1.29(0.81-1.71, P<0.0001) and 2.68(0.95-3.67), P = 0.038) for lncRNA-Cox2 and HOTAIR, respectively. Serum levels of both IL-6 and MMP-9 were significantly high in SLE patients compared with HCs (P≤0.001 for each). The up-regulated lncRNA-Cox2 was positively associated with the presence of neurological manifestations in SLE patients (P = 0.007). Furthermore, HOTAIR expression level had significantly positive correlation with IL-6 (r = 0.578, P<0.0001), MMP-9 level (r = 0.762, P<0.0001), nephritis grades (r = 0.296, P = 0.024) and proteinuria (r = 0.287, P = 0.035). LncRNA-Cox2 showed sensitivity and specificity 72.4%, and 100.0% respectively. HOTAIR sensitivity was 60.3%, and specificity was 100.0%. By multiple logistic regression analysis, lncRNA-Cox2 and HOTAIR were found as SLE independent predictors.

CONCLUSION

LncRNA-COX2 and HOTAIR can be used as new non-invasive biomarkers for the diagnosis of SLE.

Targeting HOTAIRM1 Ameliorates Glioblastoma by Disrupting Mitochondrial Oxidative Phosphorylation and Serine Metabolism

Serine hydroxymethyltransferase 2 (SHMT2), which catalyzes the conversion of serine to glycine and one-carbon transfer reactions in mitochondria, is significantly upregulated in glioblastoma (GBM). However, the mechanism by which the stability of SHMT2 gene expression is maintained to drive GBM tumorigenesis has not been clarified. Herein, through microarray screening, we identified that HOXA Transcript Antisense RNA, Myeloid-Specific 1 (HOTAIRM1) modulates the SHMT2 level in various GBM cell lines. Serine catabolism and mitochondrial oxidative phosphorylation activities were decreased by HOTAIRM1 inhibition. Mechanistically, according to our mass spectrometry and eCLIP-seq results, HOTAIRM1 can bind to PTBP1 and IGF2BP2. Furthermore, HOTAIRM1 maintains the stability of SHMT2 by promoting the recognition of an m⁶A site and the interaction of PTBP1/IGF2BP2 with SHMT2 mRNA. The stability of HOTAIRM1 can also be enhanced and results in positive feedback regulation to support the progression of GBM. Thus, targeting HOTAIRM1 could be a promising metabolic therapy for GBM.

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HOTAIRM1 regulates mitochondrial activity in GBM

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The target genes of HOTAIRM1 and the interacting RBPs were screened and identified

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SHMT2 mRNA has an m⁶A site that can be recognized by IGF2BP2

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HOTAIRM1 regulates the stability of SHMT2 by binding to PTBP1 and IGF2BP2

Circulating lnc-LOC as a novel noninvasive biomarker in the treatment surveillance of acute promyelocytic leukaemia

BACKGROUND

Acute promyelocytic leukaemia (APL) is a unique subtype of acute myeloid leukaemia (AML) characterized by haematopoietic failure caused by the accumulation of abnormal promyelocytic cells in bone marrow (BM). However, indispensable BM biopsy frequently afflicts patients in leukaemia surveillance, which increases the burden on patients and reduces compliance. This study aimed to explore whether the novel circulating long noncoding RNA LOC100506453 (lnc-LOC) could be a target in diagnosis, assess the treatment response and supervise the minimal residual disease (MRD) of APL, thereby blazing a trail in noninvasive lncRNA biomarkers of APL.

METHODS

Our study comprised 100 patients (40 with APL and 60 with non-APL AML) and 60 healthy donors. BM and peripheral blood (PB) sample collection was accomplished from APL patients at diagnosis and postinduction. Quantitative real-time PCR (qRT-PCR) was conducted to evaluate lnc-LOC expression. A receiver operating characteristic (ROC) analysis was implemented to analyse the value of lnc-LOC in the diagnosis of APL and treatment monitoring. For statistical analysis, the Mann-Whitney U test, a t test, and Spearman's rank correlation test were utilized.

RESULTS

Our results showed that BM lnc-LOC expression was significantly different between APL and healthy donors and non-APL AML. lnc-LOC was drastically downregulated in APL patients' BM after undergoing induction therapy. Lnc-LOC was upregulated in APL cell lines and downregulated after all-trans retinoic acid (ATRA)-induced myeloid differentiation, preliminarily verifying that lnc-LOC has the potential to be considered a treatment monitoring biomarker. PB lnc-LOC was positively correlated with BM lnc-LOC in APL patients, non-APL AML patients and healthy donors and decreased sharply after complete remission (CR). However, upregulated lnc-LOC was manifested in relapsed-refractory patients. A positive correlation was revealed between PB lnc-LOC and PML-RARα transcript levels in BM samples. Furthermore, we observed a positive correlation between PB lnc-LOC and BM lnc-LOC expression in APL patients, suggesting that lnc-LOC can be utilized as a noninvasive biomarker for MRD surveillance.

CONCLUSIONS

Our study demonstrated that PB lnc-LOC might serve as a novel noninvasive biomarker in the treatment surveillance of APL, and it innovated the investigation and application of newly found lncRNAs in APL noninvasive biomarkers used in diagnosis and detection.

IRF4 transcriptionally activate HOTAIRM1, which in turn regulates IRF4 expression, thereby affecting Th9 cell differentiation and involved in allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is an inflammatory reaction caused by irritation of nasal mucosa by external allergens, which seriously affects the life of patients. Here, we aimed to investigate the effect and mechanism of long non-coding RNA HOX antisense intergenic RNA myeloid 1 (lncRNA HOTAIRM1) on AR development.

METHODS

The nasal mucosa samples were collected from AR patients and AR model mice (induced by ovalbumin). T helper type 9 (Th9) cells were examined by flow cytometry. Fluorescence in situ hybridization was conducted to examine the localization of HOTAIRM1 in CD4⁺ T cells. Dual-luciferase reporter assay or RNA immunoprecipitation was conducted to examine the bond between HOTAIRM1 and miR-148a-3p, miR-148a-3p, and interferon regulatory factor 4 (IRF4). Chromatin Immunoprecipitation assay was conducted to detect the interaction between IRF4 and HOTAIRM1 promoter.

RESULTS

HOTAIRM1, interleukin-9 (IL-9), and IRF4 were highly expressed in the AR model. The ratio of Th9 cells was increased in AR mice and overexpressing HOTAIRM1 further promoted Th9 cell differentiation, while the effect was reversed after overexpression of miR-148a-3p. Besides, in vivo experiments showed that interfering with HOTAIRM1 reduced the number of sneezing and rubbing movements, reduced immunoglobulin E (IgE) and IL-9 levels, as well as Th9 cells. HOTAIRM1 was expressed in the cytoplasm and the interactions between HOTAIRM1 and miR-148a-3p, miR-148a-3p and IRF4, were confirmed. Furthermore, IRF4 bound to the HOTAIRM1 promoter and promoted its transcriptional activation.

CONCLUSION

HOTAIRM1 was highly expressed in the AR model. Besides, IRF4 activated HOTAIRM1 transcription, and HOTAIRM1, in turn, up-regulated IRF4 expression through competitively binding to miR-148a-3p with IRF4, thereby affecting Th9 cell differentiation and participating in the occurrence and development of AR. Our results suggested that interference with HOTAIRM1 might become a treatment for AR.

Overexpression of long non-coding RNA WT1-AS or silencing of PIK3AP1 are inhibitory to cervical cancer progression

Accumulating evidence demonstrate that long non-coding RNAs (lncRNAs) play an important role in regulating the biological function of cervical cancer cells. However, the regulatory role of lncRNA Wilms tumor 1 homolog antisense RNA (WT1-AS) in cervical cancer cells remains uncertain. In this study, we explored the participation of WT1-AS in cervical cancer by first using the reverse transcription quantitative polymerase-chain reaction (RT-qPCR) was to analyze the expression of WT1-AS and phosphoinositide-3-kinase adaptor protein 1 (PIK3AP1) in cervical cancer tissues and cells. Dual-luciferase reporter gene assay, RNA pull-down/RNA immunoprecipitation (RIP) assays and Chromatin Immunoprecipitation (ChIP) assay were conducted to explore the interactions among WT1-AS, PIK3AP1, and SPI1. Gain- and loss-of-function approaches were carried out to determine the effects of lncRNA WT1-AS, PIK3AP1 on cell biological characteristics, followed by assays of cell proliferation, autophagy, and apoptosis abilities using, respectively, EdU, monodansylcadaverine (MDC) staining, and flow cytometry. Finally, we measured growth of xenograft tumors in nude mice. We found decreased expression of lncRNA WT1-AS and increased expression of PIK3AP1 in cervical cancer samples. Moreover, PIK3AP1 was negatively regulated by WT1-AS, which promoted apoptosis, but inhibited cell proliferation and autophagy of cervical cancer cells. Furthermore, WT1-AS inhibited PIK3AP1 expression by recruiting SPI1, and inhibited the progression of cervical cancer through the SPI1/PIK3AP1 axis in vivo and in vitro. In summary, lncRNA WT1-AS repressed the development of cervical cancer by reducing PIK3AP1 expression through an interaction with SPI1, which may suggest new therapeutic approaches for treating cervical cancer.Abbreviations: HPV, human papillomavirus; lncRNAs, Long non-coding RNAs; WT1-AS, wilms tumor 1 antisense RNA; HCC, hepatocellular carcinoma; SFFV, Spleen focus forming virus; SPI1, Spleen focus forming virus proviral integration oncogene 1; TF, transcription factor; PIK3AP1, Phosphoinositide-3-kinase adaptor protein 1; NCBI, National Center for Biotechnology Information; oe, overexpressed; sh-PIK3AP1, short hairpin RNA against PIK3AP1; RIPA, radioimmunoprecipitation; PMSF, phenylmethylsulfonyl fluoride; HRP, horseradish peroxidase; IgG, immunoglobulin G; GAPDH, Glyceraldehyde-3-phosphate dehydrogenase; PCR, polymerase chain reaction; EP, Eppendorf; RIP, RNA-binding protein immunoprecipitation; CHIP, Chromatin immunoprecipitation; EdU, 5-ethynyl-2'-deoxyuridine; PI, propidium iodide; MDC, Monodansylcadaverine; PFA, paraformaldehyde; SPF, specific pathogen free; TV, tumor volume; DLG1-AS1, discs large MAGUK scaffold protein 1 antisense RNA 1; TOB1-AS1, transducer of epidermal growth factor receptor-2.1 antisense RNA 1; LC3II, light chain 3 type II; LC3I, light chain 3 type I; IRF4, interferon regulatory factor 4.

KDM6A Lysine Demethylase Directs Epigenetic Polarity of MDSCs during Murine Sepsis

Sepsis-induced myeloid-derived suppressor cells (MDSCs) increase mortality risk. We previously identified that long non-coding RNA Hotairm1 supports myeloid precursor shifts to Gr1+CD11b+ MDSCs during mouse sepsis. A major unanswered question is what molecular processes control Hotairm1 expression. In this study, we found by a genetic deletion that a specific PU.1-binding site is indispensable in controlling Hotairm1 transcription. We then identified H3K4me3 and H3K27me3 at the PU.1 site on the Hotairm1 promoter. Controlling an epigenetic switch of Hotairm1 transcription by PU.1 was histone KDM6A demethylase for H3K27me3 that derepressed its transcription with possible contributions from Ezh2 methyltransferase for H3K27me3. KDM6A knockdown in MDSCs increased H3K27me3, decreased H3K4me3, and inhibited Hotairm1 transcription activation by PU.1. These results enlighten clinical translation research of PU.1 epigenetic regulation as a potential sepsis immune-checkpoint treatment site.

The long noncoding RNA HOTAIRM1 controlled by AML1 enhances glucocorticoid resistance by activating RHOA/ROCK1 pathway through suppressing ARHGAP18

Acquired resistance to glucocorticoids (GCs) is an obstacle to the effective treatment of leukemia, but the molecular mechanisms of steroid insensitivity have not been fully elucidated. In this study, we established an acquired GC-resistant leukemia cell model and found a long noncoding RNA, HOTAIRM1, was overexpressed in the resistant cells by transcriptional profiling, and was higher expressed in patients with poor prognosis. The whole-genome-binding sites of HOTAIRM1 were determined by ChIRP-seq (chromatin isolation by RNA purification combined with sequencing) analysis. Further study determined that HOTAIRM1 bound to the transcriptional inhibitory region of ARHGAP18 and repressed the expression of ARHGAP18, which led to the increase of RHOA/ROCK1 signaling pathway and promoted GC resistance through antiapoptosis of leukemia cells. The inhibition of ROCK1 in GC-resistant cells could restore GCs responsiveness. In addition, HOTAIRM1 could also act as a protein sequester to prevent transcription factor AML1(acute myeloid leukemia 1) from binding to the regulatory region of ARHGAP18 by interacting with AML1. At last, we also proved AML1 could directly activate the expression of HOTAIRM1 through binding to the promoter of HOTAIRM1, which enriched the knowledge on the regulation of lncRNAs. This study revealed epigenetic causes of glucocorticoid resistance from the perspective of lncRNA, and laid a foundation for the optimization of glucocorticoid-based leukemia treatment strategy in clinic.

Long non-coding RNA HOTAIRM1-1 silencing in cartilage tissue induces osteoarthritis through microRNA-125b

Aberrations in long noncoding RNA (lncRNA) expression have been recognized in numerous human diseases. In the present study, the of role the long noncoding RNA HOX antisense intergenic RNA myeloid 1 variant (HOTAIRM1-1) in regulating the pathological progression of osteoarthritis (OA) was investigated. The aberrant expression of HOTAIRM1-1 in OA was demonstrated, but the molecular mechanisms require further analysis. The aim of the present study was to explore the function of miR-125b in modulating chondrocyte viability and apoptosis, and to address the functional association between HOTAIRM1-1 and miR-125b as potential targets. A miR-125b inhibitor was used, which laid the foundation for the following investigation. The study confirmed that HOTAIRM1-1 and miR-125b are inversely expressed in chondrocytes. The expression of HOTAIRM1-1 was downregulated and the expression of miR-125b was upregulated in tissues from patients with OA. HOTAIRM1-1 directly interacted with miR-125b in chondrocytes. HOTAIRM1-1 knockdown was associated with chondrocyte proliferation and extracellular matrix degradation. Furthermore, miR-125b reversed the effect of HOTAIRM1-1 on cell proliferation and apoptosis. In conclusion, the present study indicates that the loss of HOTAIRM1-1 function leads to aberrant increases in the proliferation and apoptosis of chondrocytes. miR-125b may be a potential downstream mechanism that regulates the function of HOTAIRM1-1, and this finding provides a therapeutic strategy for OA.

Role of miRNAs and lncRNAs in hematopoietic stem cell differentiation

Non-coding RNAs (ncRNAs) have diverse roles in the differentiation of hematopoietic cells. Among these transcripts, long ncRNAs (lncRNAs) and microRNAs (miRNAs) have especial contribution in this regard particularly by affecting levels of transcription factors that define differentiation of each linage. miR-222, miR-10a, miR-126, miR-106, miR-10b, miR-17, miR-20, miR-146, miR-155, miR-223, miR-221, miR-92, miR-150, miR-126 and miR-142 are among miRNAs that partake in the differentiation of hematopoietic stem cells. Meanwhile, this process is controlled by a number of lncRNAs such as PU.1-AS, AlncRNA-EC7, EGO, HOTAIRM1, Fas-AS1, LincRNA-EPS and lncRNA-CSR. Manipulation of expression of these transcripts has functional significance in the treatment of cancers and in cell therapy. In this paper, we have provided a brief summary of the role of miRNAs and lncRNAs in the regulation of hematopoietic stem cells.

Long non-coding RNA HOTAIR regulates myeloid differentiation through the upregulation of p21 via miR-17-5p in acute myeloid leukaemia

Long non-coding RNA HOTAIR has been reported to play a key role in regulating various biological processes in various cancers. However, the roles and mechanisms of HOTAIR in acute myeloid leukaemia (AML) are still unclear and need to be investigated. In this study, we induced differentiation of four AML cell lines by all-trans retinoic acid (ATRA) and found HOTAIR was significantly upregulated in the process. Chromatin immunoprecipitation (ChIP) assays indicated that C/EBPβ upregulated HOTAIR during ATRA induced differentiation in HL-60 cells. By gain- and loss-of-function analysis, we then observed that HOTAIR expression was positively correlated with ATRA-induced differentiation and negatively regulated G1 phase arrest in HL-60 cells. In addition, we found that HOTAIR promoted ATRA-induced differentiation via the regulation of the cell cycle regulator p21 via miR-17-5p. Moreover, we detected the expression of HOTAIR in 84 de novo AML patients, HOTAIR was found significantly downregulated in the AML patients compared to the iron deficiency anaemia (IDA) control group, negatively correlated with the platelet level in M2 patients. In all, our data suggest that HOTAIR may be subtype-specific in AML-M2 patients, also HOTAIR regulates AML differentiation by C/EBPBβ/HOTAIR/miR-17-5p/p21 pathway. The findings of the present study provide a novel insight into the mechanism of lncRNA-mediated differentiation and indicate that HOTAIR may be a promising therapeutic target for leukaemia, especially for AML with M2 type.Abbreviation: AML: acute myeloid leukaemia; APL: acute promyelocytic leukaemia; ATRA: all-trans retinoic acid; CCK8: cell Counting Kit-8; CDKs: cyclin-dependent kinases ; CeRNA: competing endogenous RNAs; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; FAB: French-American-British; FCM: flow cytometry; HOTAIR: HOX transcript antisense RNA; IDA: iron-deficiency anemia; lncRNA: long non-coding RNA; 3'UTR: 3'untranslated region; MT: Mutation type; WT: Wild type; qRT-PCR: Quantitative real-time PCR.

Emerging role of long non-coding RNAs in normal and malignant hematopoiesis

Long noncoding RNAs (lncRNAs) have recently been discovered and are increasingly recognized as vital components of modern molecular biology. Accumulating evidence shows that lncRNAs have emerged as important mediators in diverse biological processes such as cell differentiation, pluripotency, and tumorigenesis, while the function of lncRNAs in the field of normal and malignant hematopoiesis remains to be further elucidated. Here, we widely reviewed recent advances and summarize the characteristics and basic mechanisms of lncRNAs and keep abreast of developments of lncRNAs within the field of normal and malignant hematopoiesis. Based on gene regulatory networks at different levels of lncRNAs participation, lncRNAs have been shown to regulate gene expression from epigenetics, transcription and post transcription. The expression of lncRNAs is highly cell-specific and critical for the development and activation of hematopoiesis. Moreover, we also summarized the role of lncRNAs involved in hematological malignancies in recent years. LncRNAs have been found to play an emerging role in normal and malignant hematopoiesis, which may provide novel ideas for the diagnosis and therapeutic targets of hematological diseases in the foreseeable future.

The role of lncRNAs in innate immunity and inflammation

The innate immune system relies on a germ-line-encoded repertoire of pattern recognition receptors (PRRs), activated by deeply conserved pathogen signatures, such as bacterial cell wall components or foreign nucleic acids. To enable effective defence against invading pathogens and prevent from deleterious inflammation, PRR-driven immune responses are tightly controlled by a dense network of nuclear and cytoplasmic regulators. Long non-coding RNAs (lncRNAs) are increasingly recognized as important components of these regulatory circuitries, providing positive and negative control of PRR-induced innate immune responses. The present review provides an overview of the presently known roles of lncRNAs in human and murine innate antiviral and antibacterial immunity. The emerging roles in host defence and inflammation suggest that further mechanistic insights into the cellular functions of lncRNAs will decisively advance our molecular understanding of immune-associated diseases and open new avenues for therapeutic intervention.

HOTAIRM1, an enhancer lncRNA, promotes glioma proliferation by regulating long-range chromatin interactions within HOXA cluster genes

The long noncoding RNA HOTAIRM1 reportedly plays important roles in acute myeloid leukemia, gastric cancer and colorectal cancer. Here, we analyzed potential function of HOTAIRM1 in glioma and asked whether it participates in long-range chromatin interactions. We monitored expression of HOTAIRM1 in glioma tissues and correlated levels with patient survival using the TCGA dataset. HOTAIRM1 was highly expressed in glioma tissue, with high levels associated with shortened patient survival time. We then suppressed HOTAIRM1 activity in the human glioblastoma U251 line using CRISPR-cas9 to knock in a truncating polyA fragment. Reporter analysis of these and control cells confirmed that the HOTAIRM1 locus serves as an active enhancer. We then performed Capture-C analysis to identify target genes of that locus and applied RNA antisense purification to assess chromatin interactions between the HOTAIRM1 locus and HOXA cluster genes. HOTAIRM1 knockdown in glioma cells decreased proliferation and reduced expression of HOXA cluster genes. HOTAIRM1 regulates long-range interactions between the HOTAIRM1 locus and HOXA genes. Our work suggests a new mechanism by which HOTAIRM1 regulates glioma progression by regulating high-order chromatin structure and could suggest novel therapeutic targets to treat an intractable cancer.

Role of non-coding RNA networks in leukemia progression, metastasis and drug resistance

Early-stage detection of leukemia is a critical determinant for successful treatment of the disease and can increase the survival rate of leukemia patients. The factors limiting the current screening approaches to leukemia include low sensitivity and specificity, high costs, and a low participation rate. An approach based on novel and innovative biomarkers with high accuracy from peripheral blood offers a comfortable and appealing alternative to patients, potentially leading to a higher participation rate.

Recently, non-coding RNAs due to their involvement in vital oncogenic processes such as differentiation, proliferation, migration, angiogenesis and apoptosis have attracted much attention as potential diagnostic and prognostic biomarkers in leukemia. Emerging lines of evidence have shown that the mutational spectrum and dysregulated expression of non-coding RNA genes are closely associated with the development and progression of various cancers, including leukemia. In this review, we highlight the expression and functional roles of different types of non-coding RNAs in leukemia and discuss their potential clinical applications as diagnostic or prognostic biomarkers and therapeutic targets.

Myeloid-derived suppressor cells-new and exciting players in lung cancer

Lung cancer (LC) is the leading cause of cancer-related death worldwide due to its late diagnosis and poor outcomes. As has been found for other types of tumors, there is increasing evidence that myeloid-derived suppressor cells (MDSCs) play important roles in the promotion and progression of LC. Here, we briefly introduce the definition of MDSCs and their immunosuppressive functions. We next specifically discuss the multiple roles of MDSCs in the lung tumor microenvironment, including those in tumor growth and progression mediated by inhibiting antitumor immunity, and the associations of MDSCs with a poor prognosis and increased resistance to chemotherapy and immunotherapy. Finally, we also discuss preclinical and clinical treatment strategies targeting MDSCs, which may have the potential to enhance the efficacy of immunotherapy.

Myeloid-derived suppressor cells-new and exciting players in lung cancer

Lung cancer (LC) is the leading cause of cancer-related death worldwide due to its late diagnosis and poor outcomes. As has been found for other types of tumors, there is increasing evidence that myeloid-derived suppressor cells (MDSCs) play important roles in the promotion and progression of LC. Here, we briefly introduce the definition of MDSCs and their immunosuppressive functions. We next specifically discuss the multiple roles of MDSCs in the lung tumor microenvironment, including those in tumor growth and progression mediated by inhibiting antitumor immunity, and the associations of MDSCs with a poor prognosis and increased resistance to chemotherapy and immunotherapy. Finally, we also discuss preclinical and clinical treatment strategies targeting MDSCs, which may have the potential to enhance the efficacy of immunotherapy.

SP1-DLEU1-miR-4429 feedback loop promotes cell proliferative and anti-apoptotic abilities in human glioblastoma

Mounting studies have revealed that long non-coding RNA (lncRNA) deleted in lymphocytic leukemia 1 (DLEU1) positively regulated the initiation and development of various human malignant tumors. Nevertheless, the function and mechanism of DLEU1 in human glioblastoma multiforme (GBM) remain elusive and ill-defined. The current study was designed to highlight the functional role and disclose the underlying molecular mechanism by which DLEU1 regulated GBM development. We found that DLEU1 was up-regulated in GBM and DLEU1 knockdown significantly inhibited GBM cell proliferation and induced apoptosis. As predicted by bioinformatics analysis and validated in mechanistic assays, SP1 could bind to the promoter region of DLEU1 to activate DLEU1 transcription. Additionally, miR-4429 was verified as a target gene of DLEU1 and negatively modulated by DLEU1. More importantly, miR-4429 overexpression repressed the mRNA and protein levels of SP1 via binding to the 3'UTR of SP1. Overexpression of SP1 or miR-4429 inhibitor could partly abolish the effect of DLEU1 knockdown on cell viability and apoptosis in GBM. Accordingly, our experimental data revealed that SP1-DLEU1-miR-4429 formed a feedback loop to promote GBM development, providing a new evidence for the role of DLEU1 in GBM.

Long non-coding RNAs in diseases related to inflammation and immunity

Long non-coding RNAs (lncRNAs) have been key regulators of gene expression in innate and adaptive immunity. Although lncRNAs have been reported to be associated with some diseases, its expression and function in diseases related to inflammation and immunity are still unknown. We reviewed how lncRNA regulated transcription and controlled the function and balance of the cells in the immune response. In addition, we discussed the impacts and challenges of lncRNAs on immunity in diseases.

HOX cluster-embedded antisense long non-coding RNAs in lung cancer

Homeobox (HOX) genes play vital roles in embryonic development and oncogenesis. In humans, there are 39 HOX genes found in four clusters that are located on different chromosomes. The HOX clusters also contain numerous non-protein-coding RNAs, including some lncRNAs. The HOX cluster-embedded lncRNAs (HOX-lncRNAs), most notably, HOTTIP and HOTAIR play a major role in the regulation of their adjacent coding genes. Recently, most HOX-lncRNAs have been shown to impact tumorigenesis and cancer progression. Several HOX-lncRNAs, including HOTTIP, HOXA11-AS, HOTAIRM1, HOXA-AS3, HOXA10-AS, HOTAIR, and HAGLR, are dysregulated in lung cancer. Moreover, their expression levels are correlated with the clinical features of this disease. These HOX-lncRNAs regulate the proliferation, invasion, migration, and chemo-resistance of lung cancer cells through various molecular mechanisms. Although lncRNAs have received much attention lately, the functions of some HOX-lncRNAs in the development of cancer are unclear. Thus, HOX-embedded lncRNAs should be widely investigated in cancer. Here, we review the functions of HOX-lncRNAs in lung cancer.

Role of microRNAs, circRNAs and long noncoding RNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant tumor of the immature myeloid hematopoietic cells in the bone marrow (BM). It is a highly heterogeneous disease, with rising morbidity and mortality in older patients. Although researches over the past decades have improved our understanding of AML, its pathogenesis has not yet been fully elucidated. Long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are three noncoding RNA (ncRNA) molecules that regulate DNA transcription and translation. With the development of RNA-Seq technology, more and more ncRNAs that are closely related to AML leukemogenesis have been discovered. Numerous studies have found that these ncRNAs play an important role in leukemia cell proliferation, differentiation, and apoptosis. Some may potentially be used as prognostic biomarkers. In this systematic review, we briefly described the characteristics and molecular functions of three groups of ncRNAs, including lncRNAs, miRNAs, and circRNAs, and discussed their relationships with AML in detail.

USF1-induced upregulation of LINC01048 promotes cell proliferation and apoptosis in cutaneous squamous cell carcinoma by binding to TAF15 to transcriptionally activate YAP1

Previous studies have revealed that dysregulation of long non-coding RNAs (lncRNAs) can facilitate carcinogenesis. This study aims to investigate the biological role of a certain lncRNA in cutaneous squamous cell carcinoma (CSCC). According to the data of TCGA database, high expression of long intergenic non-protein coding RNA 1048 (LINC01048) is an unfavorable prognostic factor for patients with CSCC. Therefore, we further detected the expression pattern of LINC01048 in CSCC tissues. Obviously, LINC01048 was expressed higher in the CSCC tissues and recurrence tissues compared with that in adjacent normal tissues and non-recurrence tissues. Furthermore, Kaplan-Meier analysis revealed the negative correlation between LINC01048 expression and the overall survival and disease-free survival of CSCC patients. Subsequently, functional assays were conducted to prove the inhibitory effect of silenced LINC01048 on the proliferation and apoptosis of CSCC cells. Mechanistically, LINC01048 was proved to be transcriptionally activated by USF1. Pathway analysis and western blot assay showed that knockdown of LINC01048 led to the activation of Hippo pathway. Moreover, YAP1, a Hippo pathway factor, was positively regulated by LINC01048. Further mechanism investigation revealed that LINC01048 increased the binding of TAF15 to YAP1 promoter to transcriptionally activate YAP1 in CSCC cells. Finally, rescue assays demonstrated that YAP1 involved in LINC01048-mediated CSCC cell proliferation and apoptosis. In conclusion, USF1-induced upregulation of LINC01048 promoted CSCC by interacting with TAF15 to upregulate YAP1.

Long noncoding RNAs and the regulation of innate immunity and host-virus interactions

Immune responses are both pathogen and cell type-specific. The innate arm of immunity is characterized by rapid intracellular signaling cascades resulting in the production of hundreds of antimicrobial effectors that protect the host organism. Long noncoding RNAs have been shown to operate as potent modulators of both RNA and protein function throughout cell biology. Emerging data suggest that this is also true within innate immunity. LncRNAs have been shown to regulate both innate immune cell identity and the transcription of gene expression programs critical for innate immune responses. Here, we review the diverse roles of lncRNAs within innate defense with a specific emphasis on host-virus interactions.

Down-Regulation of PU.1 Gene in Pediatric Acute Lymphoblastic Leukemia Patients from South of Iran

Background: Acute lymphoblastic leukemia (ALL) is resulted from the infiltration of high amount of non-differentiated cells in bone marrow. Differentiation of the hematopoietic stem cells into specific cell lineage occurs through a highly regulated pathway which is mainly monitored during transcription step. Expression level and pattern of transcription factors e.g. PU.1 determine fate and developmental phases in this pathway. This study was performed to evaluate the expression level of the PU.1 gene in a group of children suffering from ALL. Materials and Methods: The mRNA expression level of the PU.1 gene was compared between 30 children diagnosed as new cases of ALL and 30 sex- and gender-matched healthy children in the present case-control study. The quantitative real time PCR (qRT-PCR) was used to determine the level of PU.1 gene expression. The data were analyzed using Graph Pad Prism statistical software. Results: The mRNA level of the PU.1 gene was significantly lower in the blood samples of the ALL patients compared to the controls (p= 0.002). Conclusion: The results of the study indicated that the PU.1 gene seemed to have key roles in the differentiation pathway of blood cells.

LncRNA HOTAIRM1 is involved in the progression of acute myeloid leukemia through targeting miR-148b

LncRNAs have been shown to be involved in the biological and pathological processes of acute myeloid leukemia (AML). Hox antisense intergenic RNA myeloid 1 (HOTAIRM1) was reported to be highly expressed in AML. However, the detailed role and molecular mechanism of HOTAIRM1 in AML pathogenesis remain undefined. In the present study, HOTAIRM1 and miR-148b expressions in AML patients and healthy controls were detected by qRT-PCR. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry assays, respectively. The regulatory interaction between HOTAIRM1 and miR-148b was explored by bioinformatics analysis using starBase v3.0 software and The Cancer Genome Atlas (TCGA) AML dataset. We found that the miR-148/miR-152 family members including miR-148a, miR-148b, and miR-152 were predicted to be potential targets of HOTAIRM1. HOTAIRM1 expression was negatively correlated with miR-148b expression but had no correlation with miR-148a/miR-152 expressions in AML samples from the TCGA dataset. HOTAIRM1 expression was higher while miR-148b expression was lower in AML patients than in healthy controls. A negative correlation between HOTAIRM1 and miR-148b in AML patients was observed. HOTAIRM1 silencing and miR-148b overexpression both suppressed cell proliferation and induced apoptosis in AML cells. miR-148b was identified as a target of HOTAIRM1 in AML cells. Moreover, HOTAIRM1 knockdown inhibited proliferation and induced apoptosis in AML cells by negatively regulating miR-148b. In summary, HOTAIRM1 was involved in the progression of AML through targeting miR-148b, shedding light on the biological function and molecular mechanism of HOTAIRM1 in AML.

LncRNAs have been shown to be involved in the biological and pathological processes of acute myeloid leukemia (AML).

lncRNA NTT/PBOV1 Axis Promotes Monocyte Differentiation and Is Elevated in Rheumatoid Arthritis

Monocytes/macrophages are important in orchestrating inflammatory responses. However, knowledge of the long noncoding RNA (lncRNA) regulation of monocytic cell differentiation and diseases remains limited. We aimed to elucidate the role of the 17 kb lncRNA noncoding transcript in T cells (NTT) in monocyte functions. Knockdown and chromatin immunoprecipitation (ChIP) assays in THP-1 cells (human monocytic leukemia cell line) revealed that NTT is regulated by the monocyte key transcription factor C/EBPβ and that it binds to the promoter of nearby gene PBOV1 via hnRNP-U. Overexpression of PBOV1 in THP-1 cells resulted in cell cycle G1 arrest, differentiation into macrophages, a marked increase in IL-10 and CXCL10 mRNA levels, and upregulation of the costimulatory molecules. In contrast to the downregulated NTT observed in lipopolysaccharide (LPS)-treated THP-1 cells, the C/EBPβ/NTT/PBOV1 axis was found to be hyperactivated in peripheral blood mononuclear cells (PBMCs) of first-time diagnosed untreated early rheumatoid arthritis (RA) patients, and their gene expression levels decreased markedly after treatment. Higher initial C/EBPβ/NTT/PBOV1 expression levels were associated with a trend of higher disease activity DAS28 scores. In conclusion, our study suggests that the lncRNA NTT is a regulator of inflammation in monocytes, and its activation participates in monocyte/macrophage differentiation and the pathogenesis of RA.

Potential role of LINC00996 in colorectal cancer: a study based on data mining and bioinformatics

Background

The clinical significance of LINC00996 in colorectal cancer (CRC) has not been verified. In the current study, the authors aimed to explore the expression of LINC00996 and its clinical significance in CRC based on the data mining of Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) datasets, as well as to elucidate the functions of its potential target genes.

Materials and methods

GEO and TCGA microarray datasets were used to evaluate the LINC00996 expression and its clinical significance in CRC. LINC00996 related genes were identified by Multi Experiment Matrix, RNA-Binding Protein DataBase, and The Atlas of Noncoding RNAs in Cancer. Subsequently, they were sent to gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis.

Results

LINC00996 is significantly decreased in CRC tissues compared with non-tumor tissues. Low level of LINC00996 is associated with remote metastasis and poor overall survival. However, LINC00996 has a minimal effect on gender, lymphatic invasion, tumor size, lymph node metastasis, and pathological stage. One hundred and forty-two LINC00996 related genes were identified; the results of functional analysis indicated that LINC00996 might repress tumorigenesis and metastasis via modulating the JAK-STAT, NF-κB, HIF-1, TLR, and PI3K-AKT signaling pathways.

Conclusion

Our study demonstrates that decreased LINC00996 expression may be involved in colorectal carcinogenesis and metastasis, and the depletion of LINC00996 is associated with a poor outcome in CRC patients. Moreover, the JAK-STAT, NF-κB, HIF-1, TLR, and PI3K-AKT pathways may be the key pathways regulated by LINC00996 in CRC.

Long noncoding RNAs and their epigenetic function in hematological diseases

Recent discoveries demonstrate the importance of long noncoding RNA (lncRNA) in the regulation of multiple major processes impacting development, differentiation, and metastasis of hematological diseases through epigenetic mechanisms. In contrast to genetic changes, epigenetic modification does not modify genes but is frequently reversible, thus providing opportunities for targeted treatment using specific inhibitors. In this review, we will summarize the function and epigenetic mechanism of lncRNA in malignant hematologic diseases.

HOTAIRM1 competed endogenously with miR-148a to regulate DLGAP1 in head and neck tumor cells

This study is aimed to explore the regulatory effect of lncRNA HOTAIR/miR-148a/DLGAP1 axis on head and neck tumor (HNT) cell growth, cell mobility, and invasiveness. HOTAIRM1, miR-148a, and DLGAP1 level in HNT tissues and adjacent normal tissues were measured by qRT-PCR. Cell Counting Kit-8 (CCK-8) and Transwell (migration and invasion) assay were used to survey the influence of HOTAIRM1, miR-148a, and DLGAP1 on Fadu cells. Nude mouse xenograft was utilized to validate the influence of HOTAIRM1 in vivo. Dual-luciferase reporter assay confirms the relationship between HOTAIRM1 and miR-148a, miR-148a, and DLGAP1. The expression level of HOTAIRM1 was downregulated in human HNT tissues and cells. Overexpression of HOTAIRM1 significantly moderated Fadu cells proliferation, apoptosis, migration, and invasion in vitro and impaired the tumorigenesis in vivo. The expression level of miR-148a was upregulated in human HNT tissue compared to the adjacent tissues. We identified that miR-148a was a target of HOTAIRM1 and its expression levels were reduced by HOTAIRM1. Transfection of miR-148a mimics increased proliferation, migration, and invasion of Fadu cells. DLGAP1 was identified as a novel target of miR-148a and its expression level was promoted by either HOTAIRM1 overexpression or miR-148a knockdown. Overexpression of DLGAP1 also facilitated the cell viability and metastasis of Fadu cells. HOTAIRM1 was confirmed as a tumor suppressor via sponging miR-148a and promote the expression of DLGAP1, which could be regarded as an important target for the prevention and treatment of HNT.

Long Non-Coding RNA HOXA Transcript Antisense RNA Myeloid-Specific 1-HOXA1 Axis Downregulates the Immunosuppressive Activity of Myeloid-Derived Suppressor Cells in Lung Cancer

HOXA transcript antisense RNA myeloid-specific 1 (HOTAIRM1) is a long non-coding RNA that has been shown to be a key regulator of myeloid cell development by targeting HOXA1. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that possess immunosuppressive function. However, the impact of HOTAIRM1 on the development of MDSCs remains unknown. In this study, we demonstrated that HOTAIRM1 was expressed in MDSCs and that overexpression of HOTAIRM1 could downregulate the expression of suppressive molecules in MDSCs. In addition, HOTAIRM1 levels were observed to be decreased in the peripheral blood cells of lung cancer patients compared with those of healthy controls. By analyzing HOTAIRM1 expression levels in different types of lung cancer, we found that HOTAIRM1 was mainly expressed in lung adenocarcinoma. Finally, it was confirmed that HOTAIRM1 could enhance the expression of HOXA1 in MDSCs and that high levels of HOXA1, the target gene of HOTAIRM1, could delay tumor progression and enhance the antitumor immune response by downregulating the immunosuppression of MDSCs. Taken together, this study illustrates that HOTAIRM1/HOXA1 downregulates the immunosuppressive function of MDSCs and may be a potential therapeutic target in lung cancer.

Identification of long non-coding RNAs GAS5, linc0597 and lnc-DC in plasma as novel biomarkers for systemic lupus erythematosus

Despite increasing evidence that long non-coding RNAs (lncRNAs) widely take part in human diseases, the role of lncRNAs in systemic lupus erythematosus (SLE) is largely unknown. In this study, we performed a two-stage study to explore the plasma levels of five lncRNAs (GAS5, linc0949, linc0597, HOTAIRM1 and lnc-DC) and their potential as SLE biomarkers. Compared with healthy controls, plasma levels of GAS5 and lnc-DC were significantly decreased (P < 0.001 and P = 0.002, respectively) while linc0597 were overexpressed in SLE patients (P < 0.001). When SLE patients were divided into SLE without nephritis and lupus nephritis (LN), the levels of lnc-DC were significantly higher in LN compared with SLE without nephritis (P = 0.018), but no significant difference in levels of GAS5 and linc0597 were found between LN and SLE without nephritis; plasma linc0949 level showed no significant difference in all comparisons. Further evaluation on potential biomarkers showed that GAS5, linc0597 and lnc-DC may specifically identify patients with SLE, the combination of GAS5 and linc0597 provided better diagnostic accuracy; lnc-DC may discriminate LN from SLE without nephritis. In summary, GAS5, linc0597 and lnc-DC in plasma could be potential biomarkers for SLE.

Control of Immune Cell Homeostasis and Function by lncRNAs

The immune system is composed of diverse cell types that coordinate responses to infection and maintain tissue homeostasis. In each of these cells, extracellular cues determine highly specific epigenetic landscapes and transcriptional profiles to promote immunity while maintaining homeostasis. New evidence indicates that long non-coding RNAs (lncRNAs) play crucial roles in epigenetic and transcriptional regulation in mammals. Thus, lncRNAs have emerged as key regulatory molecules of immune cell gene expression programs in response to microbial and tissue-derived cues. We review here how lncRNAs control the function and homeostasis of cell populations during immune responses, emphasizing the diverse molecular mechanisms by which lncRNAs tune highly contextualized transcriptional programs. In addition, we discuss the new challenges faced in interrogating lncRNA mechanisms and function in the immune system.

Long Noncoding RNA and Cancer: A New Paradigm

In addition to mutations or aberrant expression in the protein-coding genes, mutations and misregulation of noncoding RNAs, in particular long noncoding RNAs (lncRNA), appear to play major roles in cancer. Genome-wide association studies of tumor samples have identified a large number of lncRNAs associated with various types of cancer. Alterations in lncRNA expression and their mutations promote tumorigenesis and metastasis. LncRNAs may exhibit tumor-suppressive and -promoting (oncogenic) functions. Because of their genome-wide expression patterns in a variety of tissues and their tissue-specific expression characteristics, lncRNAs hold strong promise as novel biomarkers and therapeutic targets for cancer. In this article, we have reviewed the emerging functions and association of lncRNAs in different types of cancer and discussed their potential implications in cancer diagnosis and therapy. Cancer Res; 77(15); 3965-81. ©2017 AACR.

Regulatory mechanism and functional analysis of S100A9 in acute promyelocytic leukemia cells

S100A9, a calcium-binding protein, participates in the inflammatory process and development of various tumors, thus attracting much attention in the field of cancer biology. This study aimed to investigate the regulatory mechanism of S100A9 and its function involvement in APL. We used real-time quantitative PCR to determine whether PML/RARα affects the expression of S100A9 in NB4 and PR9 cells upon ATRA treatment. ChIP-based PCR and dual-luciferase reporter assay system were used to detect how PML/RARα and PU.1 regulate S100A9 promoter activity. CCK-8 assay and flow cytometry were employed to observe the viability and apoptosis of NB4 cells when S100A9 was overexpressed. Results showed that S100A9 was an ATRA-responsive gene, and PML/RARα was necessary for the ATRA-induced expression of S100A9 in APL cells. In addition, PU.1 could bind to the promoter of S100A9, especially when treated with ATRA in NB4 cells, and promote its activity. More importantly, overexpression of S100A9 induced the apoptosis of NB4 cells and inhibited cell growth. Collectively, our data indicated that PML/RARα and PU.1 were necessary for the ATRA-induced expression of S100A9 in APL cells. Furthermore, S100A9 promoted apoptosis in APL cells and affected cell growth.

Uncovering the roles of long non-coding RNAs in cancer stem cells

Cancer has been a major public health problem that has threatened human life worldwide throughout history. The main causes that contribute to the poor prognosis of cancer are metastasis and recurrence. Cancer stem cells are a group of tumor cells that possess self-renewal and differentiation ability, which is a vital cause of cancer metastasis and recurrence. Long non-coding RNAs refer to a class of RNAs that are longer than 200 nt and have no potential to code proteins, some of which can be specifically expressed in different tissues and different tumors. Long non-coding RNAs have great biological significance in the occurrence and progression of cancers. However, how long non-coding RNAs interact with cancer stem cells and then affect cancer metastasis and recurrence is not yet clear. Therefore, this review aims to summarize recent studies that focus on how long non-coding RNAs impact tumor occurrence and progression by affecting cancer stem cell self-renewal and differentiation in liver cancer, prostate cancer, breast cancer, and glioma.

Long noncoding RNAs: pivotal regulators in acute myeloid leukemia

Long noncoding RNAs (lncRNAs) have emerged as a class of pivotal regulators of gene expression. Recent studies have shown that lncRNAs contribute to the initiation, maintenance, and development of acute myeloid leukemia (AML). In this review, we summarize the current knowledge of the lncRNAs that play critical roles in AML. We first briefly describe the characteristics of lncRNAs, and then focus on their regulatory roles in AML, including the modulation of differentiation, proliferation, cell cycle, and apoptosis. We further emphasize the action of lncRNAs during leukemogenesis by describing how they interact with RNA, protein and chromatin DNA to exert their functions. We also highlight an urgent need to investigate the mechanisms by which lncRNAs contribute to the pathogenesis of AML. Finally, we discuss the prognostic value of lncRNAs in AML patients.

Long non-coding RNAs in the regulation of myeloid cells

Long non-coding RNAs (lncRNAs) have been attracting immense research interests. The relevance of lncRNAs in biological and physiological as well as in pathological processes has increased along with the understanding of their various regulatory mechanisms. Abundant studies have indicated that lncRNAs are involved in the differentiation, proliferation, activation, and initiation of apoptosis in different cell types. However, most studies about the regulating biology of lncRNAs are currently focused on cancer cells. This review is focused on the widely unexplored role of lncRNAs in the cell fate of myeloid cells. In this review, we summarize recent studies that have confirmed lncRNAs to be essential in the development of myeloid cells under normal and pathological conditions.