lncRNA Small Nucleolar RNA Host Gene 1 Research Articles

Integration of transcription regulation and functional genomic data reveals lncRNA SNHG6’s role in hematopoietic differentiation and leukemia

BackgroundLong non-coding RNAs (lncRNAs) are pivotal players in cellular processes, and their unique cell-type specific expression patterns render them attractive biomarkers and therapeutic targets. Yet, the functional roles of most lncRNAs remain enigmatic. To address the need to identify new druggable lncRNAs, we developed a comprehensive approach integrating transcription factor binding data with other genetic features to generate a machine learning model, which we have called INFLAMeR (Identifying Novel Functional LncRNAs with Advanced Machine Learning Resources).MethodsINFLAMeR was trained on high-throughput CRISPR interference (CRISPRi) screens across seven cell lines, and the algorithm was based on 71 genetic features. To validate the predictions, we selected candidate lncRNAs in the human K562 leukemia cell line and determined the impact of their knockdown (KD) on cell proliferation and chemotherapeutic drug response. We further performed transcriptomic analysis for candidate genes. Based on these findings, we assessed the lncRNA small nucleolar RNA host gene 6 (SNHG6) for its role in myeloid differentiation. Finally, we established a mouse K562 leukemia xenograft model to determine whether SNHG6 KD attenuates tumor growth in vivo.ResultsThe INFLAMeR model successfully reconstituted CRISPRi screening data and predicted functional lncRNAs that were previously overlooked. Intensive cell-based and transcriptomic validation of nearly fifty genes in K562 revealed cell type-specific functionality for 85% of the predicted lncRNAs. In this respect, our cell-based and transcriptomic analyses predicted a role for SNHG6 in hematopoiesis and leukemia. Consistent with its predicted role in hematopoietic differentiation, SNHG6 transcription is regulated by hematopoiesis-associated transcription factors. SNHG6 KD reduced the proliferation of leukemia cells and sensitized them to differentiation. Treatment of K562 leukemic cells with hemin and PMA, respectively, demonstrated that SNHG6 inhibits red blood cell differentiation but strongly promotes megakaryocyte differentiation. Using a xenograft mouse model, we demonstrate that SNHG6 KD attenuated tumor growth in vivo.ConclusionsOur approach not only improved the identification and characterization of functional lncRNAs through genomic approaches in a cell type-specific manner, but also identified new lncRNAs with roles in hematopoiesis and leukemia. Such approaches can be readily applied to identify novel targets for precision medicine.

LncRNA SNHG1 acts as a ceRNA for miR-216a-3p to regulate TMBIM6 expression in esophageal squamous cell carcinoma.

Background: The long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been demonstrated to play a crucial role in the progression of esophageal squamous cell carcinoma (ESCC). The current study aims to explore the deeper molecular mechanisms of SNHG1 in ESCC. Methods: Fifty patients with ESCC were enrolled to assess overall survival. Quantitative real-time PCR was performed to measure the levels of SNHG1, miR-216a-3p, and TMBIM6 in ESCC cells. Functional assessments of SNHG1 on ESCC cells were conducted using CCK-8 assay, flow cytometry, and Transwell assays. Western blot was conducted to detect the protein levels of TMBIM6 and proapoptotic proteins (Calpain and Caspase-12). The interaction among SNHG1, miR-216a-3p, and TMBIM6 was assessed with luciferase reporter assays. Results: Our study revealed that SNHG1 was notably increased in both clinical ESCC samples and cellular lines. Upregulation of SNHG1 in ESCC tissues was indicative of poor overall survival. Functionally, SNHG1 knockdown significantly inhibited the proliferation, migration, and invasion while promoting apoptosis in ESCC cells. Mechanistically, SNHG1 functioned as a competing endogenous RNA by sequestering miR-216a-3p to modulate TMBIM6 levels in ESCC cells. Notably, inhibiting miR-216a-3p or restoring TMBIM6 reversed the inhibitory effect induced by SNHG1 knockdown in ESCC cells. Conclusions: We demonstrate for the first time that SNHG1 may act as a competing endogenous RNA and promote ESCC progression through the miR-216a-3p/TMBIM6 axis. This highlights the potential of SNHG1 as a target for ESCC treatment.

LncRNA SNHG1 upregulates FANCD2 and G6PD to suppress ferroptosis by sponging miR-199a-5p/3p in hepatocellular carcinoma.

Ferroptosis is a form of regulated cell death (RCD) triggered by iron-dependent lipid peroxidation and is closely associated with the occurrence and progression of hepatocellular carcinoma (HCC). The lncRNA SNHG1 (small nucleolar RNA host gene 1) has been shown to play an oncogenic role in HCC, but its function in RCD other than autophagy and apoptosis is still unknown. Here, we investigated the correlation between SNHG1 and 156 typical markers of five RCD types based on RNA sequencing data from The Cancer Genome Atlas database and showed the negative regulators of ferroptosis FANCD2 (Fanconi anemia complementation group D2) and G6PD (glucose-6-phosphate dehydrogenase) to be the most highly and fifth most highly correlating factors with SNHG1, respectively. A competitive endogenous RNA network of SNHG1 - miR-199a-5p/3p - FANCD2/G6PD was constructed bioinformatically. In vitro experiments showed that overexpression of the miR-199a precursor led to a decrease in expression of SNHG1, FANCD2, and G6PD, whereas knockdown of SNHG1 decreased expression of FANCD2 and G6PD but increased levels of miR-199a-5p and miR-199a-3p in HCC cells (Huh7 and HepG2). In addition, knockdown of SNHG1 increased erastin-mediated ferroptosis, iron accumulation, and lipid peroxidation. These results suggest that SNHG1 upregulates FANCD2 and G6PD by sponging miR-199a, thereby inhibiting ferroptosis in HCC. Moreover, a signature based on expression of SNHG1, FANCD2, and G6PD was identified as being associated with overall survival and the immunological microenvironment in HCC. Collectively, this study identified the SNHG1-miR-199a-FANCD2/G6PD axis in HCC, which is a potential marker for the prognosis and therapy of this tumor.

Silencing LncRNA SNHG16 suppresses the diabetic inflammatory response by targeting the miR-212-3p/NF-κB signaling pathway

BackgroundLong noncoding RNAs (LncRNAs) have been identified to play an important role in diabetes. The aim of the present study was to determine the expression and function of small nucleolar RNA host gene 16 (SNHG16) in diabetic inflammation.MethodsFor the in vitro experiments, quantitative real-time PCR (qRT-PCR), Western blotting and immunofluorescence were used to detect LncRNA SNHG16 expression in the high-glucose state. The potential microRNA sponge target of LncRNA SNHG16, miR-212-3p, was detected by dual-luciferase reporter analysis and qRT-PCR. For the in vivo experiments, glucose changes in mice were detected after si-SNHG16 treatment, and SNHG16 and inflammatory factor expression in kidney tissues were detected by qRT-PCR and immunohistochemistry.ResultsLncRNA SNHG16 was upregulated in diabetic patients, HG-induced THP-1 cells, and diabetic mice. Silencing SNHG16 inhibited the diabetic inflammatory response and the development of diabetic nephropathy. miR-212-3p was found to be directly dependent on LncRNA SNHG16. miR-212-3p could inhibitor P65 phosphorylation in THP-1 cells. The miR-212-3p inhibitor reversed the action of si-SNHG16 in THP-1 cells and induced an inflammatory response in THP-1 cells. LncRNA SNHG16 was also found to be higher in the peripheral blood of diabetic patients than in the normal person. The area under the ROC curve is 0.813.ConclusionThese data suggested that silencing LncRNA SNHG16 suppresses diabetic inflammatory responses by competitively binding miR-212-3p to regulate NF-κB. LncRNA SNHG16 can be used as a novel biomarker for patients with type 2 diabetes.

Scoparone inhibits breast cancer cell viability through the NF‑κB signaling pathway.

Scoparone (SCO) is a compound found in the stems and leaves of Artemisia capillaris. The pharmacological uses of SCO include significant hypotensive, cholagogic, anti-inflammatory, analgesic, lipid-lowering, anti-asthmatic and anti-coagulant effects. The present study aimed to verify the anticancer potential of SCO in breast cancer (BC) cells and its underlying molecular mechanism. Cell Counting Kit-8 and flow cytometry were used to analyze the effects of SCO on cell viability and apoptosis. Nucleocytoplasmic separation was used to analyze the location of the long non-coding RNA (lncRNA) small nucleolar RNA host gene 12 (SNHG12) in BC cells. Reverse transcription-quantitative PCR was used to analyze the effect of SCO on the expression levels of SNHG12, microRNA (miRNA/miR)-140-3p and tumor necrosis factor receptor associated factor 2 (TRAF2). Western blotting was used to analyze the protein expression levels of TRAF2 and downstream nuclear factor κB (NF-κB) signaling pathways. The results demonstrated that SCO had a time- and dose-dependent inhibitory effect on the viability of BC cells, and that the upregulated lncRNA SNHG12 in BC cells was inhibited by SCO. SNHG12, which was primarily expressed in the cytoplasm, acted as a competing endogenous RNA, sponged miR-140-3p and inhibited the expression of miR-140-3p. The transcriptional activity and translational level of TRAF2, a downstream target of miR-140-3p, decreased following the SCO-mediated suppression of SNHG12 expression. As an upstream effector, TRAF2 activity reduction mediated the inhibition of NF-κB signaling, decreased the viability and migration of BC cells, and promoted BC cell apoptosis. In conclusion, SCO-induced inhibition of viability and promotion of apoptosis in BC cells are achieved through the inhibition of NF-κB signaling, which is associated with regulation of the SNHG12/miR-140-3p/TRAF2 axis. This understanding provides new drug candidates for the treatment of BC and a theoretical basis for biology.

Tobacco nicotine promotes TRAIL resistance in lung cancer through SNHG5.

Tobacco nicotine use is carcinogenic and a well-known risk factor for lung cancer. However, whether tobacco nicotine can induce drug resistance in lung cancer is not clear. The objective of the present study was to identify the TNF-related apoptosis-inducing ligand (TRAIL) resistance of long noncoding RNAs (lncRNAs) that are differentially expressed in smokers and nonsmokers with lung cancer. The results suggested that the nicotine upregulated small nucleolar RNA host gene 5 (SNHG5) and markedly decreased the levels of cleaved caspase-3. The present study found that cytoplasm lncRNA SNHG5 overexpression was associated with TRAIL resistance in lung cancer and that SNHG5 can interact with X-linked inhibitor of apoptosis protein to promote TRAIL resistance. Therefore, nicotine promoted TRAIL resistance in lung cancer through SNHG5/X-linked inhibitor of apoptosis protein.

LncRNA SNHG1 promotes nasopharyngeal carcinoma development via targeting miR-424-5p.

Nasopharyngeal carcinoma (NPC) is a malignant tumor of the head and neck. Distant metastasis and drug resistance are the main causes of cancer-related death. A better understanding of the molecular mechanisms that affect the progression of NPC would contribute to clinical treatment. This paper aims to investigate the effects of the long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) on biological phenotypes of NPC cells and its related mechanisms. The expression of SNHG1 and miR-424-5p in non-cancerous nasopharyngeal mucosa tissues and NPC tissues, as well as in normal nasopharyngeal epithelial cells and NPC cells was detected by qRT-PCR. HK1 and C666-1 cells were transfected with SNHG1 overexpression vector (OE-SNHG1), miR-424-5p mimic, SNHG1 knockdown vector (sh-SNHG1), or miR-424-5p inhibitor, followed by detection of transfection efficiency by qRT-PCR, cell viability by MTT, and invasive and migratory abilities by transwell invasion assay and cell scratch test. Moreover, the relationship between SNHG1 and miR-424-5p was detected by dual-luciferase reporter and RIP assays. In NPC tissues and cells, SNHG1 was upregulated but miR-424-5p was downregulated. Transfection with OE-SNHG1 or miR-424-5p inhibitor promoted proliferative, invasive, and migratory phenotypes of HK1 and C666-1 cells; transfection of sh-SNHG1 or mi-miR-424-5p induced reverse trends. Mechanistically, SNHG1 negatively regulated miR-424-5p expression, and transfection of miR-424-5p inhibitor counteracted the inhibitory effects of sh-SNHG1 on the proliferative, invasive, and migratory phenotypes of HK1 and C666-1 cells. LncRNA SNHG1 promoted proliferation, invasion and migration of NPC cells by repressing miR-424-5p expression.

LncRNA SNHG5 Suppresses Cell Migration and Invasion of Human Lung Adenocarcinoma via Regulation of Epithelial-Mesenchymal Transition.

Long noncoding RNAs (lncRNAs) are gradually being annotated as important regulators of multiple cellular processes. The goal of our study was to investigate the effects of the lncRNA small nucleolar RNA host gene 5 (SNHG5) in lung adenocarcinoma (LAD) and its underlying mechanisms. The findings revealed a substantial drop in SNHG5 expression in LAD tissues, which correlated with clinical-pathological parameters. Transcriptome sequencing analysis demonstrated that the inhibitory effect of SNHG5 was associated with cell adhesion molecules. Moreover, the expression of SNHG5 was shown to be correlated with epithelial-mesenchymal transition (EMT) markers in western blots and immunofluorescence. SNHG5 also had significant effects of antimigration and anti-invasion on LAD cells in vitro. Furthermore, the migration and invasion of A549 cells were suppressed by overexpressed SNHG5 in the EMT progress induced by transforming growth factor β1 (TGF-β1), and this might be due to the inhibition of the expression of EMT-associated transcription factors involving Snail, SLUG, and ZEB1. In LAD tissues, the expression of SNHG5 exhibited a positive association with E-cadherin protein expression but a negative correlation with N-cadherin and vimentin, according to the results of quantitative real-time PCR (qRT-PCR). In summary, the current work demonstrated that the lncRNA SNHG5 might limit cell migration and invasion of LAD cancer via decreasing the EMT process, indicating that SNHG5 might be used as a target for LAD therapeutic methods.

Downregulation of LncRNA SNHG7 Sensitizes Colorectal Cancer Cells to Resist Anlotinib by Regulating miR-181a-5p/GATA6.

Long noncoding RNAs are a novel class of regulators in human cancers. It has been reported that small nucleolar RNA hostgene 7 (SNHG7) can sponge microRNAs to regulate colorectal cancer (CRC) progression. Given its important regulatory role in cancer biology, we wondered whether SNHG7 is involved in drug resistance to anlotinib (ATB) in CRC. To answer this, we quantified the expression of SNHG7 by quantitative real-time PCR. We performed the Cell Counting Kit-8 and Colony formation assay, flow cytometric analysis, RNA pull-down, RNA-binding protein immunoprecipitation assay, and Luciferase reporter assay to confirm the interaction among SNHG7, miR-181a-5p, and GATA6. We found that SNHG7 was significantly upregulated in CRC tissues and cell lines and ATB-resistant cell lines, which was closely related to the poor overall survival of patients. Loss-of-function studies demonstrated that SNHG7 knockdown can inhibit CRC cell proliferation, increase apoptosis, and sensitize CRC cells to resist ATB. Mechanistic studies showed that SNHG7 acted as a competitive endogenous RNA to sponge miR-181a-5p to regulate the expression of GATA6, thereby promoting ATB resistance in ATB-resistant cell lines. In conclusion, SNHG7 plays an important role in ATB resistance, and it may be used to monitor ATB resistance in CRC.

METTL3 Promotes the Growth and Invasion of Melanoma Cells by Regulating the lncRNA SNHG3/miR-330-5p Axis.

Accumulating evidence indicates that m6A methyltransferase 3 (METTL3) plays a pivotal role in different malignancies including melanoma. However, the function and underlying mechanisms by which METTL3 contributes to the tumorigenesis of melanoma remain undocumented. The association of METTL3 and long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) with clinicopathological characteristics and prognosis in patients with melanoma was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and The Cancer Genome Atlas data sets. The role of METTL3 in melanoma cells was assessed by in vitro and in vivo experiments. The m6A dot blot, methylated RNA immunoprecipitation (MeRIP), and RT-qPCR were used to verify METTL3-mediated m6A modification of lncRNA SNHG3. The effect of METTL3 on lncRNA SNHG3 was determined by luciferase gene reporter assay, RT-qPCR, and Western blotting. We found that METTL3 was upregulated in melanoma tissue samples and associated with poor survival in patients with melanoma. Knockdown of METTL3 suppressed the growth and invasion of melanoma cells in vitro and in vivo, whereas restored expression of METTL3 promoted these effects. Mechanistic investigations showed that knockdown of METTL3 reduced SNHG3 m6A levels and its messenger ribonucleic acid (mRNA) expression levels. SNHG3 could act as a sponge of microRNA (miR)-330-5p to upregulate the expression of CCHC-type zinc finger nucleic acid binding protein (CNBP). SNHG3 overexpression reversed METTL3-knockdown-caused antitumor effects, miR-330-5p upregulation and CNBP downregulation. SNHG3 had a positive correlation with METTL3 expression but a negative correlation with miR-330-5p expression in melanoma tissue samples. In conclusion, our findings demonstrated that METTL3-mediated m6A modification of lncRNA SNHG3 promoted the growth and invasion of melanoma cells by regulating the miR-330-5p/CNBP axis.

Long non‑coding RNA SNHG5 promotes osteogenic differentiation of human periodontal ligament stem cells via mediating miR‑23b‑3p/Runx2 axis.

The treatment of bone loss due to periodontitis has posed a great challenge for physicians for decades. Therefore, it is of extraordinary significance to identify an effective regeneration scheme for alveolar bone. This study aimed to investigate long non-coding RNA (lncRNA) small nucleolar RNA host gene 5 (SNHG5) whether sponges microRNA-23b-3p (miR-23b-3p) to achieve the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). Results revealed that the expression of SNHG5 was upregulated whereas that of miR-23b-3p was downregulated in osteogenic hPDLSCs. Alizarin red staining assays and qRT-PCR demonstrated that SNHG5 silencing or miR-23b-3p overexpression inhibits hPDLSCs osteogenic differentiation and vice versa. In addition, miR-23b-3p partially abolished the promotive effect of SNHG5 on osteogenic differentiation of hPDLSCs. Dual luciferase report and RNA pulldown assay verified that miR-23b-3p is a regulatory target of SNHG5 and that Runx2 is a gene target of miR-23b-3p. In brief, the results demonstrate that SNHG5 promotes the osteogenic differentiation of hPDLSCs by regulating the miR-23b-3p/Runx2 axis. Our study provides novel mechanistic insights into the critical role of lncRNA SNHG5 as a miR-23b-3p sponge to regulate Runx2 expression in hPDLSCs and may serve as a potential therapeutics target for periodontitis.

LncRNA SNHG6 promotes glycolysis reprogramming in hepatocellular carcinoma by stabilizing the BOP1 protein

ABSTRACT Metabolic reprogramming is an important feature in tumor progression. Long noncoding RNA’s (lncRNA) small nucleolar RNA host gene 6 (SNHG6) acts as a proto-oncogene in hepatocellular carcinoma (HCC) but its role in glycolysis is mostly unknown. The role of SNHG6 and Block of proliferation 1 (BOP1) on glycolysis is assessed by glucose uptake, lactate production, oxygen consumptive rate (OCR) and extracellular acidification rate (ECAR) and glycolytic enzyme levels. The regulatory effect of SNHG6 on BOP1 protein was confirmed by Western blotting, MS2 pull-down, RNA pull-down, and RIP assay. SNHG6 and BOP1 levels were increased in HCC tissues and cells. SNHG6 and BOP1 were prognostic factors in HCC patients and significantly correlated to TP53 mutant and tumor grade. SNHG6 promoted proliferation, inhibited apoptosis, enhanced glucose uptake and lactate production, decreased OCR, and increased ECAR in HCC cell lines. SNHG6 could bind the BOP1 protein and enhance its stability. BOP1 overexpression rescued the change of proliferation, apoptosis, and glycolysis in HCCLM3 and SMMC-7721 cells. Our data indicate that SNHG6 accelerates proliferation and glycolysis and inhibits the apoptosis of HCC cell lines by binding the BOP1 protein and enhancing its stability. Both SNHG6 and BOP1 are promising prognostic and therapeutic markers in HCC.

Long non-coding RNAs and small nucleolar RNA host gene 6 contribute to the depression-like behavior of hypothyroid mice by promoting methylation of the brain-derived neuropathic factor promoter that is mediated by DNA methyltransferase 1.

Long non-coding RNAs (lncRNAs) and small nucleolar RNA host gene 6 (SNHG6) have attracted extensive attention due to their involvement in various pathological processes. However, the functional role of lncRNA SNHG6 in depression-like behavior induced by hypothyroidism is still largely unknown. Our study was designed to explore the biological role of lncRNA SNHG6 in depression-like behavior induced by hypothyroidism and the underlying mechanisms. First, the depression-like behavior of hypothyroid mice was investigated after lncRNA SNHG6 knockdown. Subsequently, the regulation of the methylation levels of the brain-derived neurotrophic factor (BDNF) promoters by lncRNA SNHG6 was evaluated. To reveal the underlying mechanisms of lncRNA SNHG6 in the methylation of the BDNF promoters, RNA pull-down assays, RNA immunoprecipitation, and co-immunoprecipitation were performed. Further experiments were also conducted to investigate the roles of DNA (cytosine-5)-methyltransferase 1 (DNMT1) in the depression-like behavior induced by hypothyroidism. In this study, elevated levels of lncRNA SNHG6 were noted in the hippocampus in hypothyroid mice. Function assays proved that lncRNA SNHG6 knockdown alleviated the depression-like behavior induced by hypothyroidism. Furthermore, a mechanistic investigation validated that lncRNA SNHG6 stabilized DNMT1 by blocking UHRF1-mediated DNMT1 ubiquitination, which increased the methylation levels of the BDNF promoters. Moreover, DNMT1 was found to be involved in depression-like behavior in hypothyroid mice. Our findings revealed a novel mechanism by which lncRNA SNHG6 promotes the methylation levels of the BDNF promoters by stabilizing DNMT1 and sheds light on potential therapeutic strategies for depression-like behavior induced by hypothyroidism.

LncRNA SNHG1 regulates neuroblastoma cell fate via interactions with HDAC1/2

The small nucleolar RNA host gene 1 (SNHG1) is a novel oncogenic long non-coding RNA (lncRNA) aberrantly expressed in different tumor types. We previously found highly expressed SNHG1 was associated with poor prognosis and MYCN status in neuroblastoma (NB). However, the molecular mechanisms of SNHG1 in NB are still unclear. Here, we disrupted endogenous SNHG1 in the MYCN-amplified NB cell line SK-N-BE(2)C using the CRISPR/Cas9 system and demonstrated the proliferation and colony formation ability of SNHG1-knowndown cells were suppressed. The transcriptome analysis and functional assays of SNHG1-knockdown cells revealed SNHG1 was involved in various biological processes including cell growth, migration, apoptosis, cell cycle, and reactive oxygen species (ROS). Interestingly, the expression of core regulatory circuitry (CRC) transcription factors in MYCN-amplified NB, including PHOX2B, HAND2, GATA3, ISL1, TBX1, and MYCN, were decreased in SNHG1-knockdown cells. The chromatin-immunoprecipitation sequencing (ChIP-seq) and transposase-accessible chromatin using sequencing (ATAC-seq) analyses showed that chromatin status of these CRC members was altered, which might stem from interactions between SNHG1 and HDAC1/2. These findings demonstrate that SNHG1 plays a crucial role in maintaining NB identity via chromatin regulation and reveal the function of the lncRNA SNHG1 in NB.

Long non-coding RNA SNHG16 decreased SMAD4 to induce gemcitabine resistance in pancreatic cancer via EZH2-mediated epigenetic modification.

Gemcitabine resistance (GR) in pancreatic cancer (PC) results in poor patient outcomes. SMAD family member (Smad4) dysregulation is a significant role of GR in PC, and EZH2 is involved in Smad4 expression in tumor progression. Interestingly, lncRNA small nucleolar RNA host gene 16 (SNHG16) might interact with EZH2, indicating a potential pathway to overcome gemcitabine-resistant PC progression. We investigated the role of the SNHG16/EZH2/Smad4 pathway in gemcitabine-resistant PC cells (PANC-1/GR and SW1990/GR). First, we found that SNHG16 was upregulated both in wild-type PC cells and in gemcitabine-resistant PC cells. SNHG16 overexpression reduced gemcitabine cytotoxicity and apoptosis in PC cells. Meanwhile, SNHG16 upregulation caused p-Akt elevation and Smad4 reduction. However, SNHG16 silencing induced the opposite trend. Then, we found that EZH2 was enriched in SNHG16 based on RIP and RNA pulldown. In particular, SNHG16 overexpression promoted the interaction between EZH2 and the Smad4 promoter according to Chromatin immunoprecipitation-quantitative polymerase chain reaction. Finally, both EZH2 inhibition and Smad4 upregulation increased gemcitabine cytotoxicity and apoptosis in PC cells during SNHG16 overexpression. Moreover, both treatments decreased p-Akt and increased Smad4. Collectively, lncRNA SNHG16 decreased Smad4 to induce GR in PC via EZH2-mediated epigenetic modification.

LncRNA SNHG16 is Downregulated in Pneumonia and Downregulates miR-210 to Promote LPS-Induced Lung Cell Apoptosis.

Long non-coding RNA Small Nucleolar RNA Host Gene 16 (SNHG16) has been reported to participate in Lipopolysaccharide (LPS)-induced inflammatory pathway, which contributes to pneumonia. This study was therefore conducted to explore the role of SNHG16 in pneumonia. In this study, expression of SNHG16 and microRNA (miR)-210 in pneumonia plasma samples (n = 56) and control samples (n = 60) was detected by RT-qPCR. The potential crosstalk between SNHG16 and miR-210 was analyzed by performing overexpression experiments. MSP was performed to study the role of SNHG16 in methylation of miR-210 gene. Cell apoptosis was analyzed by cell apoptosis assay. Decreased expression levels of SNHG16 and increased expression levels of miR-210 were observed in pneumonia. SNHG16 showed an inverse correlation to miR-210. LPS treatment led to downregulated SNHG16 and upregulated miR-210 in Human Bronchial Epithelial Cells (HBEpCs). In HBEpCs, SNHG16 downregulated miR-210 and increased miR-210 DNA gene methylation. Moreover, SNHG16 suppressed the role of miR-210 in cell apoptosis under LPS treatment. In conclusion, SNHG16 is downregulated in pneumonia, and it downregulates miR-210 possibly through methylation to promote lung cell apoptosis induced by LPS.

CircRNA, lncRNA, and mRNA profiles of umbilical cord blood exosomes from preterm newborns showing bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) represents a multifactorial chronic pulmonary pathology and a major factor causing premature illness and death. The therapeutic role of exosomes in BPD has been feverishly investigated. Meanwhile, the potential roles of exosomal circRNAs, lncRNAs, and mRNAs in umbilical cord blood (UCB) serum have not been studied. This study aimed to detect the expression profiles of circRNAs, lncRNAs, and mRNAs in UCB-derived exosomes of infants with BPD. Microarray analysis was performed to compare the RNA profiles of UCB-derived exosomes of a preterm newborn with (BPD group) and without (non-BPD, NBPD group) BPD. Then, circRNA/lncRNA–miRNA–mRNA co-expression networks were built to determine their association with BPD. In addition, cell counting kit-8 (CCK-8) assay was used to evaluate the proliferation of lipopolysaccharide (LPS)-induced human bronchial epithelial cells (BEAS-2B cells) and human umbilical vein endothelial cells (HUVECs). The levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in LPS-induced BEAS-2B cells and HUVECs were assessed through Western blot analysis. Then, quantitative reverse transcription–polymerase chain reaction assay was used to evaluate the expression levels of four differentially expressed circRNAs (hsa_circ_0086913, hsa_circ_0049170, hsa_circ_0087059, and hsa_circ_0065188) and two lncRNAs (small nucleolar RNA host gene 20 (SNHG20) and LINC00582) detected in LPS-induced BEAS-2B cells or HUVECs. A total of 317 circRNAs, 104 lncRNAs, and 135 mRNAs showed significant differential expression in UCB-derived exosomes of preterm infants with BPD compared with those with NBPD. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to examine differentially expressed exosomal circRNAs, lncRNAs, and mRNAs. The results showed that the GO terms and KEGG pathways mostly involving differentially expressed exosomal RNAs were closely associated with endothelial or epithelial cell development. In vitro, CCK-8 and Western blot assays revealed that LPS remarkably inhibited the viability and promoted inflammatory responses (TNF-α and IL-1β) of BEAS-2B cells or HUVECs. The expression levels of circRNAs hsa_circ_0049170 and hsa_circ_0087059 were upregulated in LPS-induced BEAS-2B cells; the expression level of hsa_circ_0086913 was upregulated and that of hsa_circ_0065188 was downregulated in LPS-induced HUVECs. Moreover, the expression level of lncRNA SNHG20 was upregulated and that of LINC00582 was downregulated in LPS-induced BEAS-2B cells. Further, 455 circRNA/lncRNA–miRNA–mRNA interaction networks were predicted, including hsa_circ_0086913/hsa-miR-103a-3p/transmembrane 4 L six family member 1 (TM4SF1) and lncRNA-SNHG20/hsa-miR-6720-5p/spermine synthase (SMS) networks, which may take part in BPD.Conclusion: This study provided a systematic perspective on UCB-derived exosomal circRNAs and lncRNAs and laid an important foundation for further investigating the potential biological functions of exosomal circRNAs and lncRNAs in BPD.What is Known:• BPD represents a multifactorial chronic pulmonary pathology and a major factor causing premature illness and death.• The therapeutic role of exosomes in BPD has been feverishly investigated, and exosomal RNAs were ignored.What is New:• The profiles of UCB-derived exosomal circRNAs, lncRNAs, and mRNAs were performed.• Several differentially expressed circRNAs and lncRNAs were identified in LPS-induced BEAS-2B cells and HUVECs.

Modulation of cisplatin resistance in gastric cancer by LncRNA SNHG15

Background: The role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) in cisplatin-resistance was studied in gastric cancer.
 Methods: The relative SNHG15 expression and its correlation with survival were assayed on the Cancer Genome Atlas data and confirmed with the clinical samples we collected. Cisplatin-resistant MKN45 cell line (MKN45 CR) was established. SNHG15 plasmid and SNHG15 shRNA plasmid were transfected into MKN45 cells and MKN45 CR cells. Colony formation analysis and cell counting kit-8 assay were utilized to determine cell proliferation and viability. The binding between SNHG15 and zeste 2 polycomb repressive complex 2 subunit (EZH2) was testified with RNA immunoprecipitation (RIP). The promoter activity of phosphatase and tensin homolog (PTEN) was evaluated by luciferase reporter assay.
 Results: High SNHG15 expression was correlated with the poor overall survival of gastric cancer patients, and cisplatin treatment can induce time and dose-dependent up-regulation of SNHG15. At the same time, SNHG15 overexpression could promote the cisplatin resistance, while SNHG15 inhibition could diminish the cisplatin resistance. RIP assays confirmed the interaction of SNHG15 with EZH2. More importantly, SNHG15 inhibited PTEN promoter activity by reducing EZH2 recruitment in MKN45 CR cells.
 Conclusion: SNHG15 epigenetically prohibits PTEN expression by recruiting EZH2 in gastric cancer cisplatin-resistant cells.

Long non-coding RNA SNHG3 promotes prostate cancer progression by sponging microRNA-1827.

Long non-coding RNAs (lncRNAs) are important biological factors that contribute to the initiation and progression of different types of cancer, including gastric, bladder and colorectal cancer. Small nucleolar RNA host gene 3 (SNHG3) has been implicated in prostate cancer (PCa) progression. However, the expression pattern and function of SNHG3 in PCa remain unclear, impeding the development of novel treatment strategies for this cancer. The present study aimed to investigate a combination of molecular and biochemical approaches to determine the role of SNHG3 in patients at different stages of disease, and elucidate the pathway by which SNHG3 affects PCa progression. A Cell Counting Kit-8 assay was used to assess cell proliferation. Transwell assays were used to analyze cell migration and invasion. Reverse transcription-quantitative PCR and western blotting were used to evaluate the expression levels of RNAs and proteins, respectively. The results demonstrated that SNHG3 expression was upregulated in PCa tissues downloaded from The Cancer Genome Atlas database, which was associated with poor prognosis. Furthermore, cell proliferation, migration and invasion were significantly inhibited following SNHG3 knockdown in vitro, the effects of which were reversed following overexpression of SNHG3 in PCa cells. Bioinformatic analysis revealed that microRNA (miRNA/miR)-1827 was a downstream target of SNHG3. The direct interaction between SNHG3 and miR-1827 was validated via the dual-luciferase reporter and RNA immunoprecipitation assays. Pearson's correlation analysis demonstrated that SNHG3 expression was negatively correlated with miR-1827 expression at different stages of PCa. Furthermore, rescue assays indicated that cotransfection with small interfering-SNHG3 and miR-1827 inhibitor reversed the effects of SNHG3 knockdown on cell proliferation, migration and invasion. In addition, SNHG3 knockdown in vivo suppressed tumor growth. Notably, lncRNA SNHG3 promoted PCa progression through miR-1827 via the Wnt/AKT/mTOR pathway. Taken together, the results of the present study suggest that SNHG3 promotes PCa progression by sponging miR-1827, indicating that SNHG3 may be a promising diagnostic and therapeutic target of PCa.

LncRNA SNHG15 as a ceRNA modulates Osteoclast Differentiation, Proliferation, and Metastasis by Sponging miR-381-3p/NEK2 Axis.

Background A growing number of studies have shown that long noncoding RNAs play an important role in osteoclast differentiation. However, there are few studies on the roles of lncRNA small nucleolar RNA host gene 15 (SNHG15) in osteoclast differentiation. Methods The expressions of SNHG15, miR-381-3p, and never in mitosis-related kinase 2 (NEK2) mRNA were detected by real-time quantitative polymerase chain reaction (RT-qPCR); Western blot detected NEK2 and osteoclast markers (Cathepsin K, CTSK), matrix metalloproteinase 9 (MMP9), nuclear factor of activated T cell 2 (NFAT2), and tartrate-resistant acid phosphatase (TRAP) protein levels; cell proliferation was detected by Cell Counting Kit-8 (CCK-8), and the formation of osteoclasts was observed by TRAP staining; the F-actin skeleton was stained with tetramethylrhodamine isothiocyanate (TRITC) phalloidin; cell migration rate was detected by Transwell; dual-luciferase reporter gene assay and RNA-binding protein immunoprecipitation (RIP) assay verified the targeting relationship between miR-381-3p, SNHG15, and NEK2. Results The expression of SNHG15 was increased in THP-1 cells stimulated by macrophage colony-stimulating factor (M-CSF)/receptor activator of nuclear factor-kappa B ligand (RANKL). Overexpression of SNHG15 significantly promoted the proliferation, migration, osteoclast differentiation, and expression of osteoclast markers CTSK, MMP9, NFAT2, and TRAP of THP-1 cells induced by M-CSF/RANKL. Knockdown of SNHG15 reversed this effect. Overexpression of SNHG15 downregulated the inhibitory effect of overexpression of miR-381-3p on the proliferation, migration, and differentiation of THP-1 cells induced by M-CSF/RANKL. Knockdown of miR-381-3p reversed the inhibitory effect of knockdown of NEK2 on the proliferation, migration, and differentiation of THP-1 cells induced by M-CSF/RANKL. Conclusion SNHG15 acted as a ceRNA promoted the proliferation, migration, and differentiation of THP-1 cells induced by M-CSF/RANKL through sponging miR-381-3p to promote the expression of NEK2.