lncRNA HOTAIRM1 Research Articles

Exosome-encapsulated lncRNA HOTAIRM1 contributes to PM2.5-aggravated COPD airway remodeling by enhancing myofibroblast differentiation.

Emphysema, myofibroblast accumulation and airway remodeling can occur in the lungs due to exposure to atmospheric pollution, especially fine particulate matter (PM2.5), leading to chronic obstructive pulmonary disease (COPD). Specifically, bronchial epithelium-fibroblast communication participates in airway remodeling, which results in COPD. An increasing number of studies are now being conducted on the role of exosome-mediated cell-cell communication in disease pathogenesis. Here, we investigated whether exosomes generated from bronchial epithelial cells could deliver information to normal stromal fibroblasts and provoke cellular responses, resulting in airway obstruction in COPD. We studied the mechanism of exosome-mediated intercellular communication between human bronchial epithelial (HBE) cells and primary lung fibroblasts (pLFs). We found that PM2.5-induced HBE-derived exosomes promoted myofibroblast differentiation in pLFs. Then, the exosomal lncRNA expression profiles derived from PM2.5-treated HBE cells and nontreated HBE cells were investigated using an Agilent Human LncRNA Array. Combining coculture assays and direct exosome treatment, we found that HBE cell-derived exosomal HOTAIRM1 facilitated the myofibroblast differentiation of pLFs. Surprisingly, we discovered that exosomal HOTAIRM1 enhanced pLF proliferation to secrete excessive collagen secretion, leading to airway obstruction by stimulating the TGF-β/SMAD3 signaling pathway. Significantly, PM2.5 reduced FEV1/FVC and FEV1 and increased the level of serum exosomal HOTAIRM1 in healthy people; moreover, serum exosomal HOTAIRM1 was associated with PM2.5-related reductions in FEV1/FVC and FVC. These findings show that PM2.5 triggers alterations in exosome components and clarify that one of the paracrine mediators of myofibroblast differentiation is bronchial epithelial cell-derived HOTAIRM1, which has the potential to be an effective prevention and therapeutic target for PM2.5-induced COPD.

LncRNA HOTAIRM1 Inhibits the Proliferation and Invasion of Lung Adenocarcinoma Cells via the miR-498/WWOX Axis [Retraction

[This retracts the article DOI: 10.2147/CMAR.S244573.].

LncRNA HOTAIRM1 Activated by HOXA4 Drives HUVEC Proliferation Through Direct Interaction with Protein Partner HSPA5

Despite the substantial progress in deciphering the pathogenesis of atherosclerosis (AS), cardiovascular mortality is still increasing. Therefore, atherosclerotic cardiovascular disease remains a sweeping epidemic that jeopardizes human health. Disentangling the molecular underpinnings of AS is imperative in the molecular cardiology field. Overwhelming evidence has indicated that the recognition of a fascinating class of players, known as long non-coding RNAs (lncRNAs), provides causality for coordinating AS. However, the function and mechanism of HOTAIRM1 are still poorly understood in human umbilical vein endothelial cells (HUVECs) and AS. Herein, we primarily underscored that lncRNA HOTAIRM1 is potentially responsible for AS; as such, it was dramatically up-regulated in HUVECs upon ox-LDL stimulation. Functionally, HOTAIRM1 knockdown attenuated HUVEC proliferation and potentiated apoptosis in the absence and presence of ox‐LDL. Furthermore, HOTAIRM1 was preferentially located in the nuclei of HUVECs. Mechanistically, HOXA4 is directly bound to the HOTAIRM1 promoter and activated its transcription. Of note, a positive feedback signaling between HOXA4 and HOTAIRM1 was determined. Intriguingly, the interplay between HOTAIRM1 and HSPA5 occurred in an RNA-binding protein pattern and a transcription-dependent regulatory manner. In addition, HSPA5 overexpression partially antagonized HUVEC proliferation inhibition of HOTAIRM1 depletion. Taken together, our findings delineate a pivotal functional interaction among HOXA4, HOTAIRM1, and HSPA5 as a novel regulatory circuit for modulating HUVEC proliferation. An in-depth investigation of the HOXA4-HOTAIRM1-HSPA5 axis promises to yield significant breakthroughs in identifying the molecular mechanisms governing AS and developing therapeutic avenues for AS.Graphical

LncRNA-HOTAIRM1 promotes aerobic glycolysis and proliferation in osteosarcoma via the miR-664b-3p/Rheb/mTOR pathway.

Osteosarcoma (OS), which is a common and aggressive primary bone malignancy, occurs mainly in children and adolescent. Long noncoding RNAs (lncRNAs) are reported to play a pivotal role in various cancers. Here, we found that the lncRNA HOTAIRM1 is upregulated in OS cells and tissues. A set of functional experiments suggested that HOTAIRM1 knockdown attenuated the proliferation and stimulated the apoptosis of OS cells. A subsequent mechanistic study revealed that HOTAIRM1 functions as a competing endogenous RNA to elevate ras homologue enriched in brain (Rheb) expression by sponging miR-664b-3p. Immediately afterward, upregulated Rheb facilitates proliferation and suppresses apoptosis by promoting the mTOR pathway-mediated Warburg effect in OS. In summary, our findings demonstrated that HOTAIRM1 promotes the proliferation and suppresses the apoptosis of OS cells by enhancing the Warburg effect via the miR-664b-3p/Rheb/mTOR axis. Understanding the underlying mechanisms and targeting the HOTAIRM1/miR-664b-3p/Rheb/mTOR axis are essential for OS clinical treatment.

Overexpression of the lncRNA HOTAIRM1 promotes lenvatinib resistance by downregulating miR-34a and activating autophagy in hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is one of the most common malignant cancers in humans and has a high fatality rate. Despite pharmacological advances such as sorafenib and lenvatinib approval, responses are seen only in a limited fraction of HCCs, and the majority of HCC patients do not benefit from this treatment. In recent years, researchers have verified that the long noncoding RNAs (lncRNAs) impact the efficiency of lenvatinib and the prognosis of patients with HCC.Materials and methodsThis work obtained gene expression profile from an Arraystar lncRNA microarray. Expression of HOTAIRM1, Beclin-1, and p62 in HCC was characterized in clinical HCC tissues of 24 patients with HCC. Overexpression and knockdown experiments were performed in HCC cells to examine the effects of the HOTAIRM1 on lenvatinib sensitivity. The interactions between HOTAIRM1, miR-34a and Beclin-1 were predicted according to GSEA and CNC network. The effects of HOTAIRM1, autophagy and lenvatinib on tumor inhibit were validated in orthotopic tumor-bearing nude mouse model.ResultsLenvatinib-resistant HCC cell lines were established using the concentration gradient method. Data from an Arraystar lncRNA microarray indicated that HOTAIRM1, a specific lncRNA located in an evolutionarily highly conserved HOX gene cluster, was differentially expressed between lenvatinib-resistant HCC cells and their parental cells. Expression of HOTAIRM1 and Beclin-1 in HCC was characterized in clinical HCC tissues of 24 patients who have different sensitivity to lenvatinib. Knocking down of HOTAIRM1 decreased the autophagy level in lenvatinib-resistant HCC cells and increased their sensitivity to lenvatinib, especially when combined with autophagy inhibitors both in vitro and in vivo. Further study indicated that knocking down HOTAIRM1 in lenvatinib-resistant cell lines increased the level of miR-34a and inhibited the expression of Beclin-1 in Huh7-R and HepG2-R cells. Investigation according to GSEA and CNC network, lncRNA and nearby coding gene and lncRNA-miRNA analyses demonstrated that the resistance of HCC to lenvatinib was affected by the HOTAIRM1-miR-34a-Beclin-1 regulatory axis.ConclusionHOTAIRM1 is an independent drug resistance factor which significantly associated with the efficacy of lenvatinib in HCC. HOTAIRM1 may downregulation of miR-34a and upregulation of Beclin-1, leading to activation of autophagy, thereby inducing lenvatinib resistance in HCC.

LncRNA HOTAIRM1 promotes dental follicle stem cell-mediated bone regeneration by regulating HIF-1α/KDM6/EZH2/H3K27me3 axis.

Large bone defect reconstruction undergoes hypoxia and remains a major practical challenge. Bone tissue engineering with a more promising stem cell source facilitates the development of better therapeutic outcomes. Human dental follicle stem cells (hDFSCs) with superior multipotency, osteogenic capacity, and accessibility have been proven a promising cell source for bone regeneration. We previously identified a novel long noncoding RNA (lncRNA), HOTAIRM1, to be highly expressed in hDFSCs. Here we found that HOTAIRM1 overexpressed hDFSCs promoted bone regeneration in rat critical-size calvarial defect model. Mechanically, HOTAIRM1 was induced in hDFSCs under hypoxic conditions and activated HIF-1α. RNA-sequencing analysis indicated that HOTAIRM1 upregulated oxygen-sensing histone demethylases KDM6A/B and suppressed methyltransferase EZH2 via targeting HIF-1α. The osteogenic differentiation of hDFSCs was accompanied with demethylation of H3K27, and HOTAIRM1 overexpression decreased the distribution of H3K27me3 in osteogenic genes, including ALP, M-CSF, Wnt-3a, Wnt-5a, Wnt-7a, and β-catenin, thus promoted their transcription. Our study provided evidence that HOTAIRM1 upregulated KDM6A/B and inhibited EZH2 in a HIF-1α dependent manner to enhance the osteogenesis of hDFSCs. HOTAIRM1-mediated hDFSCs may serve as a promising therapeutic approach to promote bone regeneration in clinical practice.

Single-cell analyses reveal distinct expression patterns and roles of long non-coding RNAs during hESC differentiation into pancreatic progenitors

BackgroundDeep understanding the differentiation process of human embryonic stem cells (hESCs) is essential for developing cell-based therapeutic strategy. Substantial efforts have been made to investigate protein-coding genes, yet it remains lacking comprehensive characterization of long non-coding RNAs (lncRNAs) during this process.MethodshESCs were passaged every 5–6 days and had maintained stable karyotype even until the 50th generation. Pancreatic progenitor specification of in vitro differentiation from hESCs was performed and modified. The nuclei were stained with 4,6-Diamidino-2-phenylindole (DAPI). Droplet-based platform (10X Genomics) was applied to generate the single-cell RNA sequencing (scRNA-seq) data. The quality of the filtered read pairs was evaluated by using FastQC. Batch effects were removed using the size factor method. Dimension reduction and unsupervised clustering analyses were performed using Seurat R package. The Monocle 2 and MetaCell algorithms were used to order single cells on a pseudotime course and partition the scRNA-seq data into metacells, respectively. Co-expression network was constructed using WGCNA. Module- and hub-based methods were adopted to predict the functions of lncRNAs.ResultsA total of 77,382 cells during the differentiation process of hESCs toward pancreatic progenitors were sequenced. According to the single-cell map, the cells from different time points were authenticated to constitute a relatively homogeneous population, in which a total of 7382 lncRNAs could be detected. Through further analyzing the time course data, conserved and specific expression features of lncRNAs during hESC differentiation were revealed. Based upon pseudotime analysis, 52 pseudotime-associated lncRNAs that grouped into three distinct expression patterns were identified. We also implemented MetaCell algorithm and network-based methods to explore the functional mechanisms of these lncRNAs. Totally, 464 lncRNAs, including 49 pseudotime-associated lncRNAs were functionally annotated by either module-based or hub-based methods. Most importantly, we demonstrated that the lncRNA HOTAIRM1, which co-localized and co-expressed with several HOX genes, may play crucial role in the generation of pancreatic progenitors through regulation of exocytosis and retinoic acid receptor signaling pathway.ConclusionsOur single-cell analyses provide valuable data resources for biological researchers and novel insights into hESC differentiation processes, which will guide future endeavors to further elucidate the roles of lncRNAs.

LncRNA HOTAIRM1 functions in DNA double-strand break repair via its association with DNA repair and mRNA surveillance factors.

The eukaryotic exon junction complex component Y14 participates in double-strand break (DSB) repair via its RNA-dependent interaction with the non-homologous end-joining (NHEJ) complex. Using immunoprecipitation-RNA-seq, we identified a set of Y14-associated long non-coding RNAs (lncRNAs). The lncRNA HOTAIRM1 serves as a strong candidate that mediates the interaction between Y14 and the NHEJ complex. HOTAIRM1 localized to near ultraviolet laser-induced DNA damage sites. Depletion of HOTAIRM1 delayed the recruitment of DNA damage response and repair factors to DNA lesions and compromised the efficiency of NHEJ-mediated DSB repair. Identification of the HOTAIRM1 interactome revealed a large set of RNA processing factors including mRNA surveillance factors. The surveillance factors Upf1 and SMG6 localized to DNA damage sites in a HOTAIRM1-dependent manner. Depletion of Upf1 or SMG6 increased the level of DSB-induced non-coding transcripts at damaged sites, indicating a pivotal role for Upf1/SMG6-mediated RNA degradation in DNA repair. We conclude that HOTAIRM1 serves as an assembly scaffold for both DNA repair and mRNA surveillance factors that act in concert to repair DSBs.

A combination of transcriptome and methylation analyses reveals the role of lncRNA HOTAIRM1 in the proliferation and metastasis of breast cancer.

DNA methylation status is strongly associated with the prognosis of breast invasive carcinoma (BRCA). Elucidating the mechanisms underlying DNA methylation coupled with determining its biological function is imperative to the effective development of treatment and prevention strategies for breast cancer. We retrieved transcriptome and DNA methylation profiles of BRCA patients from The Cancer Genome Atlas (TCGA) database, then applied the "limma" package in R software to identify differentially expressed genes (DEGs) and aberrantly methylated genes. Next, we used the "MethylMix" package to screen for methylation-driven genes, and performed univariate and multivariate Cox regression analyses to determine the prognostic value of the methylation-driven genes and clinical characteristics. We validated these findings in 51 breast cancer tissues alongside 51 corresponding normal tissues. Furthermore, we used cell experiments to clarify the biological function and underlying molecular mechanisms of HOTAIRM1 in vitro. A total of 25 methylation-driven genes were identified in the dataset. Results from univariate and multivariate Cox regression showed that SYN2, HOTAIRM1, BCAS1, and ALDOC were significantly associated with patient prognosis. Immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR) results showed that the expression levels of SYN2 and HOTAIRM1 were negatively correlated with BRCA stage, whereas those of BCAS1 and ALDOC were positively correlated with BRCA stage. Results from in vitro experiments showed that knockdown HOTAIRM1 expression promoted breast cancer cells proliferation, clone formation, and invasion. Up-regulation of HOTAIRM1 inhibited breast cancer cells proliferation, clone formation, and invasion. In summary, low HOTAIRM1 expression is a significant prognostic factor for the survival of BRCA patients and thus could be a potential therapeutic target for the treatment of BRCA.

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

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. 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. 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. 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.

The Curcumin Analog Da0324 Inhibits the Proliferation of Gastric Cancer Cells via HOTAIRM1/miR-29b-1-5p/PHLPP1 Axis.

Background: Our previous study has shown that Da0324, a curcumin analog, exhibited significantly improved stability and antitumor activity. However, the molecular mechanisms of action of Da0324 remain poorly understood. Long non-coding RNA (lncRNA) has been shown to play a key role in tumor progression. Here, we aim to investigate the molecular mechanisms underlying the anti-cancer activity of Da0324 by regulating the lncRNA HOTAIRM1.Methods: Gastric cancer cell lines were treated with Da0324 and/or transfected with lentiviral vector expressing HOTAIRM1 shRNA, and/or miR-29b-1-5p mimics and/or small interference RNA (siRNA) against PHLPP1, or HOTAIRM1 siRNA or lentiviral vector expressing HOTAIRM1, as needed. The expression of HOTAIRM1, miR-29b-1-5p and PHLPP1 in GC cells was determined by Real-Time PCR. Cell growth was examined by CCK-8 assay and colony formation assay in vitro. The targeted relationship between HOTAIRM1 and miR-29b-1-5p was verified by luciferase reporter gene assay. PHLPP1 protein expression was examined by Western blotting.Results: Da0324 increased the expression of HOTAIRM1 in GC cells. HOTAIRM1 expression was significantly down-regulated in GC tissues, and the low expression of HOTAIRM1 was associated with the shorter survival rate of GC patients based on the TCGA database. Knockdown of HOTAIRM1 promoted GC cell proliferation whereas overexpression of HOTAIRM1 inhibited GC cell proliferation as demonstrated by CCK-8 and colony formation assays. Moreover, knockdown of HOTAIRM1 reversed the Da0324-mediated growth inhibition of GC cells. Furthermore, HOTAIRM1 acted as a sponge for miR-29b-1-5p and PHLPP1 is regulated by the HOTAIRM1/miR-29b-1-5p axis in GC cells. Overexpression of miR-29b-1-5p or knockdown of PHLPP1 reversed the ability of Da0324 to inhibit the growth of GC cells.Conclusions: Our data suggest that Da0324 exerts antitumor activity by regulating HOTAIRM1/miR-29b-1-5p/PHLPP1 axis in GC cells, and provide new insights into the anti-cancer mechanism of Da0324.

Skp2 promotes APL progression through the stabilization of oncoprotein PML-RARα and the inhibition of JunB expression

AimsTo investigate the role of Skp2 and JunB on acute promyelocytic leukemia (APL) progression and the related mechanism. Materials and methodsThe expression of Skp2 in NB4 cell line was depleted to explore its effect on proliferation and differentiation both in vitro and in vivo assays. Western blot and quantitative RT-PCR analysis were performed to explore Skp2-regulated downstream target genes. Luciferase and co-immunoprecipitation analysis indicated that PML-RARα inhibited the transactivation of JunB by interacting with the PU.1 protein. The western blot analysis confirmed that Skp2 could maintain the stability of PML-RARα. Key findingsWe report that the progression of APL and the attenuation of APL sensitivity to ATRA are positively associated with Skp2. Elevated Skp2 expression promotes APL progression by decreasing the expression of lncRNA HOTAIRM1 and inactivation of GSK3β, causing autophagy inhibition followed by the suppression of PML-RARα ubiquitylation and degradation, which represses JunB transcriptional activation through PU.1/PML-RARα transcriptional complex to block cell differentiation. Coupled with ATRA or GSK3β inhibitor treatment, genetic or pharmacological inhibition of Skp2 strikingly induces JunB expression by accelerating the degradation of PML-RARα, which contributes to the eradication of APL. Additionally, the expressions of Skp2 and JunB are negatively correlated in mice subcutaneous leukemia xenograft tumors. SignificanceCollectively, this study uncovers the roles of Skp2 in PML-RARα stabilization and in APL oncogenic functions. We reveal a novel mechanism of PML-RARα degradation and JunB regulation that constitute an important signaling network of Skp2-GSK3β-PML/RARα-JunB.

Mutant NPM1-regulated lncRNA HOTAIRM1 promotes leukemia cell autophagy and proliferation by targeting EGR1 and ULK3

BackgroundAcute myeloid leukemia (AML) with mutated nucleophosmin (NPM1), which displays a distinct long noncoding RNA (lncRNA) expression profile, has been defined as a unique subgroup in the new classification of myeloid neoplasms. However, the biological roles of key lncRNAs in the development of NPM1-mutated AML are currently unclear. Here, we aimed to investigate the functional and mechanistic roles of the lncRNA HOTAIRM1 in NPM1-mutated AML.MethodsThe expression of HOTAIRM1 was analyzed with a public database and further determined by qRT-PCR in NPM1-mutated AML samples and cell lines. The cause of upregulated HOTAIRM1 expression was investigated by luciferase reporter, chromatin immunoprecipitation and ubiquitination assays. The functional role of HOTAIRM1 in autophagy and proliferation was evaluated using western blot analysis, immunofluorescence staining, a Cell Counting Kit-8 (CCK-8) assay, a 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay, flow cytometric analyses and animal studies. The action mechanism of HOTAIRM1 was explored through RNA fluorescence in situ hybridization, RNA pulldown and RNA immunoprecipitation assays.ResultsHOTAIRM1 was highly expressed in NPM1-mutated AML. High HOTAIRM1 expression was induced in part by mutant NPM1 via KLF5-dependent transcriptional regulation. Importantly, HOTAIRM1 promoted autophagy and proliferation both in vitro and in vivo. Mechanistic investigations demonstrated that nuclear HOTAIRM1 promoted EGR1 degradation by serving as a scaffold to facilitate MDM2-EGR1 complex formation, while cytoplasmic HOTAIRM1 acted as a sponge for miR-152-3p to increase ULK3 expression.ConclusionsTaken together, our findings identify two oncogenic regulatory axes in NPM1-mutated AML centered on HOTAIRM1: one involving EGR1 and MDM2 in the nucleus and the other involving the miR-152-3p/ULK3 axis in the cytoplasm. Our study indicates that HOTAIRM1 may be a promising therapeutic target for this distinct leukemia subtype.

Author Correction: LncRNA HOTAIRM1 inhibits the progression of hepatocellular carcinoma by inhibiting the Wnt signaling pathway.

Correction to: European Review for Medical and Pharmacological Sciences 2018; 22 (15): 4861-4868-DOI: 10.26355/eurrev_201808_15622-PMID: 30070317, published online 15 August 2018. After publication, the authors found some mistakes in the article. There are amendments to thispaper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/15622.

PFOI stimulates the motility of T24 bladder cancer cells: Possible involvement and activation of lncRNA malat1

Perfluorinated iodine alkanes (PFIs) can serve as an important raw materials for the synthesis of various perfluorinated chemical products through telomerization reaction. The estrogenic effects of PFIs have been reported previously by some in vitro and in vivo screening assays. To explore the potential epigenetic toxicity of PFIs, activation of lncRNAs was screened, and the cell motility changes induced by perfluorooctyl iodide (PFOI) were analyzed in this study. High metastatic bladder cell line (T24) was used to investigate the cellular migration function affected by PFOI. PFOI exposure significantly induced the upregulation of lncRNA anril, thorlnc, hotairm1, meg3, and malat1. The migration and invasion of T24 cells were also enhanced upon PFOI exposure. The transcription level of matrix metalloenzyme genes, epidermal growth factors, cytoskeleton genes, and the upstream factors involved in cell motility pathways were examined to illustrate possible mechanisms. Additionally, the basic role of malat1 in cellular motility was investigated by lncRNA knockdown and migration assays. The knockdown of malat1 inhibited the cellular motility induced by PFOI. The levels of MMP-2/-9 genes were also down-regulated by the treatment of si-malat1. Overall, the perturbation of cytoskeleton genes (E-cadherin/N-cadherin) may account for the impact on the motility of T24 cells. Our studies indicate that perfluorinated chemicals might regulate the lncRNAs, thus promoting the metastasis of the tumor cells.

LncRNA HOTAIRM1, miR-433-5p and PIK3CD function as a ceRNA network to exacerbate the development of PCOS

BackgroundCurrently, several non-coding RNAs (ncRNAs) were distinguished in polycystic ovarian syndrome (PCOS). This present study aims to explore the potential function of lncRNA HOTAIRM1/miR-433-5p/PIK3CD in ovarian granulosa cells.MethodsWe analyzed the expression profiles of HOTAIRM1, miR-433-5p and PIK3CD in PCOS samples by enquiring GEO database. GSEA was applied to enrich the pathways related to PCOS. The target association between HOTAIRM1 and miR-433-5p or the binding association between miR-433-5p and PIK3CD were assessed by online prediction tools and a dual luciferase reporter assay. qPCR and western blotting assays were used to detect PIK3CD expression after HOTAIRM1 and miR-433-5p treatment. The proliferation and apoptosis of ovarian granulosa cells were estimated by cell counting kit-8 and flow cytometry assays, respectively.ResultsThe expression profiles of HOTAIRM1 and PIK3CD were increased, whereas miR-433-5p was decreased in PCOS tissues. PIK3CD expression was positively regulated by HOTAIRM1 and negatively modulated by miR-433-5p. Overexpression of HOTAIRM1 reduced the proliferative ability and increased the apoptotic ability of granulosa cells, whereas upregulation of miR-433-5p or downregulation of PIK3CD reversed the effects of HOTAIRM1 on granulosa cells. Moreover, overexpression of miR-433-5 displayed a results with increasing proliferative ability and decreasing apoptotic ability, but upregulation of PIK3CD eliminated the function of miR-433-5p on granulosa cells.ConclusionsOur findings illustrated that HOTAIRM1 could sponge miR-433-5p to promote PIK3CD expression, thereby regulating the growth and apoptosis of granulose cells in PCOS.

LncRNA HOTAIRM1 regulates cell proliferation and themetastasis of thyroid cancer by targeting Wnt10b.

Long non-coding RNAs play a role in a variety of malignancies, such as thyroid cancer (TC). However, the effects and function of lincRNA HOTAIRM1 (LINC HOTAIRM1) in TC remains obscure. In the present study, the expression of HOTAIRM1 was evaluated in TC tissues and cells by RT-qPCR and the association between the lncRNA and disease progression was assessed. In vitro, the biological function of HOTAIRM1 was assessed in TC. Moreover, changes in the expression of Wnt10b were measured by western blot analysis. In addition, MTT assay, bioinformatics analysis and luciferase assays were performed to determine the target binding effect between LINC HOTAIRM1 and miR-148a, as well as that between Wnt10b and miR-148a. The changes in the metastatic ability of TPC-1 and BCPAP cells were evaluated by Transwell assay. The pronounced upregulated expression of HOTAIRM1 was evident in TC cells and tissues, and was associated with TNM stage and lymph node metastasis. When HOTAIRM1 was knocked down, this inhibited the proliferative and invasive abilities of TPC-1 and BCPAP cells in vitro. The knockdown of this lncRNA also increased the expression of microRNA-148a (miR-148a) and decreased Wnt10b expression in these cells, whereas transfection with miR-148a inhibitor was sufficient to overcome this Wnt10b downregulation. In line with these results, the overexpression of miR-148a markedly suppressed Wnt10b expression, whereas miR-148a inhibition resulted in the opposite effects. The overexpression of Wnt10b was also sufficient to overcome the effects of miR-148a mimics on TPC-1 and BCPAP cells. Taken together, these results suggest that miR-148a and Wnt10b are downstream effectors of the HOTAIRM1 signaling pathway in TC. This HOTAIRM1/miR-148a/Wnt10 axis may thus be amenable to therapeutic targeting in order to improve disease outcomes in patients with TC.

Upregulation of HOTAIRM1 increases migration and invasion by glioblastoma cells.

Long noncoding RNAs (lncRNAs) promote invasion and migration by glioblastoma (GBM) cells. In this study, quantitative real-time polymerase chain reaction was used to detect expression levels of the lncRNA HOTAIRM1 in GBM tissue samples and cells. The function of HOTAIRM1 was examined using wound healing assays, transwell assays, and in vivo experiments after GBM cells were transfected with either sh-ctrl or sh-HOTAIRM1. Luciferase reporter assays and RIP assays were performed to determine the interactions between HOTAIRM1 and miR-153-5p and between miR-153-5p and SNAI2. We also used luciferase reporter assays and ChIP assays to assess the transcriptional regulation of HOTAIRM1 by SNAI2 and CDH1. HOTAIRM1 was significantly overexpressed in GBM tissues and cells. HOTAIRM1 knockdown significantly weakened the migration and invasion by GBM cells. HOTAIRM1 was found to sponge miR-153-5p, and SNAI2 is a direct target of miR-153-5p. In addition, SNAI2 was shown to force HOTAIRM1 expression through directly promoting transcription and suppressing the negative regulation of CDH1 on transcription. Our results indicate a positive feedback loop between HOTAIRM1 and SNAI2, and suggest that the lncRNA HOTAIRM1 is a potential biomarker and therapeutic target in GBM.

Genomic amplification of long noncoding RNA HOTAIRM1 drives anaplastic thyroid cancer progression via repressing miR-144 biogenesis

ABSTRACT Genomic aberrations are frequently found in anaplastic thyroid cancer (ATC). However, the functional genes in aberrantly genomic regions are largely unclear. In this study, we identified a long noncoding RNA (lncRNA) HOTAIRM1, whose encoding gene was amplified and expression was upregulated in ATC compared with papillary thyroid cancer and normal thyroid. Increased genomic copy number and expression of HOTAIRM1 were both correlated with poor survival of ATC patients. Functional assays revealed that HOTAIRM1 promoted proliferation, inhibited apoptosis, and promoted migration and invasion of ATC cells in vitro, and promoted ATC tumour growth and metastasis in vivo. HOTAIRM1 was found to bind ILF3, repress the binding between ILF3 and precursor miR-144 (pre-miR-144), block the effects of ILF3 on stabilizing pre-miR-144, and therefore downregulate pre-miR-144. Intriguingly, HOTAIRM1 was also found to directly bind primary miR-144 (pri-miR-144), repress the binding between pri-miR-144 and DROSHA, block the processing of pri-miR-144 by DROSHA, and therefore upregulate pri-miR-144 and downregulate pre-miR-144. Thus, HOTAIRM1 remarkably downregulated pre-miR-144 and further downregulated miR-144. Knockdown of ILF3 and DROSHA abolished the effects of HOTAIRM1 on pre-miR-144 and miR-144. The expression of miR-144 was downregulated and reversely correlated with HOTAIRM1 in ATC. Via repressing miR-144 biogenesis, HOTAIRM1 upregulated MET and activated AKT signalling. miR-144 overexpression reversed the oncogenic roles of HOTAIRM1 in ATC. Altogether, these findings identified a genomic copy number amplified and highly expressed lncRNA HOTAIRM1, which exerted oncogenic roles via repressing miR-144 biogenesis in ATC. Our data suggested HOTAIRM1 as a potential prognostic biomarker and therapeutic target for ATC.

LncRNA HotairM1 Depletion Promotes Self-Renewal of Cancer Stem Cells through HOXA1-Nanog Regulation Loop

In cancer cells, a gain of stemness may have profound implications for tumor initiation, aggressiveness, and clinical outcome. However, the molecular mechanisms underlying the self-renewal maintenance of cancer stem-like cells (CSCs) remain elusive. Here, based on analysis of transcriptome sequencing, we identified a long noncoding RNA (lncRNA) named HotairM1, which is weakly expressed in human colorectal carcinoma and uveal melanoma, and a much lower expression in corresponding CSCs. Our results showed that HotairM1 depletion could promote CSC self-renewal and tumor propagation. Mechanistically, HotairM1 recruit EZH2 and SUZ12 to the promoter of its target gene HOXA1, leading to histone H3K27 trimethylation and epigenetic silencing of HOXA1. The silence of HOXA1 subsequently induces the H3K27 acetylation at the enhancer site of Nanog gene to upregulate its expression. The enrichment of Nanog could further inhibit HOXA1 expression, forming a reciprocal regulation loop augmenting the stemness maintaining effect. In summary, our results revealed a lncRNA-based regulatory loop that sustains self-renewal of CSCs, which highlights the critical role of HotairM1 in CSC development through the HOXA1-Nanog signaling loop.