Small Nucleolar RNA Host Gene 1 Expression Research Articles

Long non‑coding RNA SNHG1 promotes autophagy in vascular smooth muscle cells induced by facilitating CLEC7A.

Long non‑coding RNAs serve a crucial role in autophagy of vascular smooth muscle cells (VSMCs). The present study aimed to investigate the effect of small nucleolar RNA host gene 1 (SNHG1) on autophagy in VSMCs and the associated underlying mechanisms. Rapamycin was used to induce autophagy in VSMCs and the effects of SNHG1 on the proliferation and migration of VSMCs and the change in phenotype were tested following overexpression and silencing of SNHG1. The target gene of SNHG1 was predicted and validated. SNHG1‑regulated autophagy of VSMCs via C‑type lectin domain family 7 member A (CLEC7A) was determined by combined silencing of SNHG1 and overexpression of CLEC7A. Rapamycin‑induced autophagy in VSMCs changed the cell phenotype from contractile to synthetic, with decreased expression of α‑smooth muscle actin and smooth muscle protein 22a and increased expression of osteopontin. Overexpression of SNHG1 caused the same change in phenotype while the opposite change was observed following SNHG1 silencing. Overexpression of SNHG1 promoted the proliferation and migration of VSMCs. CLEC7A was identified as a target gene of SNHG1 and a direct binding relationship between them was confirmed by RNA immunoprecipitation and RNA pull‑down assays. Overexpression of SNHG1 increased the expression of CLEC7A. The expression of both SNHG1 and CLEC7A was increased during autophagy of VSMCs. Overexpression of SNHG1 promoted autophagy of VSMCs and silencing of CLEC7A reduced this effect of SNHG1. In conclusion, SNHG1 and CLEC7A were increased in VSMCs following autophagy. SNHG1 promotes the conversion of VSMCs from a contractile phenotype to a synthetic phenotype by facilitating CLEC7A expression.

SNHG14 promotes triple-negative breast cancer cell proliferation, invasion, and chemoresistance by regulating the ERK/MAPK signaling pathway.

The functional role and molecular mechanisms of small-nucleolar RNA host gene 14 (SNHG14) in triple-negative breast cancer (TNBC) progression remain unclear. The expression levels of SNHG14 in breast cancer samples and cell lines were determined using real-time quantitative polymerase chain reaction. Cell proliferation, migration, and invasion abilities were detected using MTS and transwell assays. By RNA sequencing, differentially expressed genes were identified between the SNHG14 siRNA and the negative control group. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to predict the targets and pathways regulated by SNHG14. pRAF, pMEK, and pERK expression were measured by western blot. The xenograft model was constructed to access the biological function of SNHG14 in vivo. A minimal patient-derived xenograft model was established to evaluate the sensitivity to chemotherapy drugs. Our data indicated that SNHG14 expression was increased in TNBC tissues and cell lines. SNHG14 knockdown attenuated the proliferation, migration, and invasion abilities of TNBC cells both in vivo and in vitro. High SNHG14 expression was associated with lymph node metastasis and a high Ki67 index. The targets of SNHG14 were mainly enriched in the MAPK signaling pathway. pRAF, pMEK, and pERK expression were downregulated after being transfected with SNHG14 siRNA. Compared with the negative control group, the expression of CACNA1I, DUSP8, FGF17, FGFR4, FOS, PDGFRB, and DDIT3 was increased, and the expression of MKNK1 was decreased in the SNHG14 siRNA group. Minimal patient-derived xenograft model demonstrated that knockdown of SNHG14 enhanced the sensitivity to Docetaxel in vivo. Compared with the DMSO group, the proliferation of Docetaxel-resistant MDA-MB-231 cells was decreased in Dabrafenib, PD184352, and FR180204 treatment groups. SNHG14 knockdown inhibits TNBC progression by regulating the ERK/MAPK signaling pathway, which provides evidence for SNHG14 as a potential target for TNBC therapy.

LncRNA SNHG1 facilitates colorectal cancer cells metastasis by recruiting HNRNPD protein to stabilize SERPINA3 mRNA

Metastasis continues to negatively impact individuals diagnosed with colorectal cancer (CRC). Research has revealed the important role of long noncoding RNAs (lncRNAs) in CRC metastasis, but the underlying mechanisms remain unclear. Here, we revealed that the lncRNA small nucleolar RNA host gene 1 (SNHG1) is expressed at higher levels in metastatic CRC tissues than in primary CRC tissues, and that high lncRNA SNHG1 expression indicates poor patient outcomes. We found that lncRNA SNHG1 promotes the migration and invasion of tumor cells both in vivo and in vitro. Moreover, lncRNA SNHG1 increases serpin family A member 3 (SERPINA3) mRNA stability by interacting with the heterogeneous nuclear ribonucleoprotein D (HNRNPD) protein, and subsequently upregulates SERPINA3 expression. Moreover, HNRNPD and SERPINA3 reversed the effects of lncRNA SNHG1 knockdown on CRC cell metastasis. In conclusion, we report that the lncRNA SNHG1 recruits HNRNPD, in turn upregulating SERPINA3 expression and ultimately facilitating CRC cell migration and invasion. Targeting the lncRNA SNHG1/HNRNPD/SERPINA3 signaling pathway might be a therapeutic option for preventing CRC metastasis.

Roles of long non‑coding RNA SNHG16 in human digestive system cancer (Review).

The incidence of tumors in the human digestive system is relatively high, including esophageal cancer, liver cancer, pancreatic cancer, gastric cancer and colorectal cancer. These malignancies arise from a complex interplay of environmental and genetic factors. Among them, long non‑coding RNAs (lncRNAs), which cannot be translated into proteins, serve an important role in the development, progression, migration and prognosis of tumors. Small nucleolar RNA host gene 16 (SNHG16) is a typical lncRNA, and its relationship with digestive system tumors has been widely explored. The prevailing hypothesis suggests that the principal molecular mechanism of SNHG16 in digestive system tumors involves it functioning as a competitive endogenous RNA that interacts with other proteins, regulates various genes and influences a downstream target molecule. The present review summarizes recent research on the relationship between SNHG16 and numerous types of digestive system cancer, encompassing its biological functions, underlying mechanisms and potential clinical implications. Furthermore, it outlines the association between SNHG16 expression and pertinent risk factors, such as smoking, infection and diet. The present review indicated the promise of SNHG16 as a potential biomarker and therapeutic target in human digestive system cancer.

Endoplasmic Reticulum Stress Potentiates the Immunosuppressive Microenvironment in Hepatocellular Carcinoma by Promoting the Release of SNHG6-Enriched Small Extracellular Vesicles.

Endoplasmic reticulum (ER) stress leads to hepatocellular carcinoma (HCC) progression. Small extracellular vesicles (sEV) play a crucial role in modulating the tumor microenvironment (TME) by influencing cellular communication and immune responses. However, it is unclear whether ER stress modulates the TME through sEVs. In the current study, we investigated the effects and underlying mechanisms of ER stress on the HCC TME. In vivo and in vitro experiments showed that overactivated ER stress was a salient attribute of the immunosuppressive HCC TME. This was caused by the ATF4-promoted release of small nucleolar RNA host gene 6 (SNHG6)-carrying sEVs, which attenuated T cell-mediated immune responses. Overall, SNHG6 modulated the immunosuppressive TME and aggravated ER stress. Meanwhile, targeting SNHG6 facilitated M1-like macrophage and CD8+ T-cell infiltration and decreased the proportion of M2-like macrophages. In addition, SNHG6 knockdown enhanced anti-PD1 immunotherapeutic efficacy. Moreover, in HCC patients, overexpression of SNHG6 was associated with a lack of response to anti-PD1 therapy and poor prognosis, whereas low SNHG6 expression was associated with improved therapeutic efficacy and prognoses. These data indicate that a correlation exists among ER stress, sEVs, immunosuppressive HCC TME, and immunotherapeutic efficacy. Hence, SNHG6-targeted therapy may represent an effective strategy for patients with HCC.

LncRNA SNHG14 silencing attenuates the progression of diabetic nephropathy via the miR-30e-5p/SOX4 axis.

Diabetic nephropathy (DN) is a diabetic complication. LncRNAs are reported to participate in the pathophysiology of DN. Here, the function and mechanism of lncRNA small nucleolar RNA host gene 14 (SNHG14) in DN were explored. Streptozotocin (STZ)-induced DN mouse models and high glucose (HG)-treated human mesangial cells (MCs) were used to detect SNHG14 expression. SNHG14 silencing plasmids were applied to examine the function of SNHG14 on proliferation and fibrosis in HG-treated MCs. Potential targets of SNHG14 were predicted using bioinformatics tools and verified by luciferase reporter, RNA pulldown, and northern blotting assays. The functional role of SNHG14 in DN in vivo was detected by injection with adenoviral vector carrying sh-SNHG14 into DN mice. Serum creatinine, blood urea nitrogen, blood glucose, 24-h proteinuria, relative kidney weight, and renal pathological changes were examined in DN mice. SNHG14 expression was elevated in the kidneys of DN mice and HG-treated MCs. SNHG14 silencing inhibited proliferation and fibrosis of HG-stimulated MCs. SNHG14 bound to miR-30e-5p to upregulate SOX4 expression. In rescue assays, SOX4 elevation diminished the effects of SNHG14 silencing in HG-treated MCs, and SOX4 silencing reversed the effects of SNHG14 overexpression. In in vivo studies, SNHG14 downregulation significantly ameliorated renal injuries and renal interstitial fibrosis in DN mice. SNHG14 silencing attenuates kidney injury in DN mice and reduces proliferation and fibrotic phenotype of HG-stimulated MCs via the miR-30e-5p/SOX4 axis.

Small nucleolar RNA host gene 5 plays a role in orthodontic tooth movement by inhibiting osteoclast differentiation.

The alveolar bone remodelling promoted by reasonable mechanical force triggers orthodontic tooth movement (OTM). The generation of osteoclasts is essential in this process. However, the mechanism of mechanical force mediating osteoclast differentiation remains elusive. Small nucleolar RNA host gene 5 (SNHG5), which was reported to mediate the osteogenic differentiation of bone marrow mesenchymal stem cells in our previous study, was downregulated in human periodontal ligament cells (hPDLCs) under mechanical force. At the same time, the RANKL/OPG ratio increased. Based on this, we probed into the role of SNHG5 in osteoclast formation during OTM and the relevant mechanism. SNHG5 and the RANKL/OPG ratio under different compressive forces were detected by western blotting (WB) and qRT-PCR. Impact of overexpression or knockdown of SNHG5 on osteoclast differentiation was detected by qRT-PCR, WB and transwell experiments. The combination of SNHG5 and C/EBPβ was verified by RNA immunoprecipitation and RNA pull-down assays. The expression of SNHG5 and osteoclast markers in gingiva were analysed by qRT-PCR and the paraffin sections of periodontal tissues were used for histological analysis. Compressive force downregulated SNHG5 and upregulated the RANKL/OPG ratio in hPDLCs. Overexpression of SNHG5 inhibited RANKL's expression and osteoclast differentiation. SNHG5 combined with C/EBPβ, a regulator of osteoclast. The expression of SNHG5 in periodontal tissue decreased during OTM. SNHG5 inhibited osteoclast differentiation during OTM, achieved by affecting RANKL secretion, which may provide a new idea to interfere with bone resorption during orthodontic treatment.

The potential role of SNHG16/ miRNA-146a/ TRAF6 signaling pathway in the protective effect of zoledronate against colorectal cancer and associated osteoporosis in mouse model

Bone fracture as a consequence of colorectal cancer (CRC) and associated osteoporosis (OP) is considered a risk factor for increasing the mortality rate among CRC patients. SNHG16/ miRNA-146a/ TRAF6 signaling pathway is a substantial contributor to neoplastic evolution, progression, and metastasis. Here, we investigated the effect of zoledronate (ZOL) on the growth of CRC and associated OP in a mouse model. Thirty Balb/c mice were divided into Naïve, azoxymethane (AOM)/dextran sodium sulfate (DSS), and ZOL groups. Body weight and small nucleolar RNA host gene 16 (SNHG16) expression, microRNA-146a, and TRAF6 in bone, colon, and stool were investigated. Samples of colon and bone were collected and processed for light microscopic, immunohistochemical staining for cytokeratin 20 (CK20), nuclear protein Ki67 (pKi-67), and caudal type homeobox transcription factor 2 (CDx2) in colon and receptor activator of nuclear factor kB (RANK) and osteoprotegerin (OPG) in bone. A computerized tomography (CT) scan of the femur and tibia was studied. ZOL produced a significant decrease in the expression of SNHG16 and TRAF6 and an increase in miRNA-146a in the colon and bone. ZOL administration improved the histopathological changes in the colon, produced a significant decrease in CK20 and Ki-67, and increased CDx2 expressions. In bone, ZOL prevented osteoporotic changes and tumour cell invasion produced a significant decrease in RANK and an increase in OPG expressions, alongside improved bone mineral density in CT scans. ZOL could be a promising preventive therapy against colitis-induced cancer and associated OP via modulation expression of SNHG16, miRNA-146a, and TRAF6.

Small nucleolar RNA host gene 1 silence inhibits the lipopolysaccharide-induced microglial apoptosis and inflammation.

Microglia activation is an early mediator of neuroinflammation and a major contributor to spinal damage and motor dysfunction. This study was designed to investigate the role of small nucleolar RNA host gene 1 (SNHG1) on the apoptosis and inflammatory response of microglial cell BV-2 and its underlying molecular mechanism. The C5 lamina contusion-induced mouse model of spinal cord injury (SCI) was constructed. Mouse microglia BV2 was stimulated by lipopolysaccharide (LPS) to establish the in vitro model of SCI. The quantitative reverse transcription polymerase chain reaction method was used to quantify RNA expression levels. Enzyme-linked immunosorbent assays were used to quantify concentrations of inflammatory cytokines. Protein levels were assessed by western blotting, and apoptosis was assessed by flow cytometry. Dual luciferase reporter gene assay and RNA pull-down assay were conducted to investigate the binding relationships between molecules. Upregulation of SNHG1 and downregulation of miR-195-5p were observed in the spinal cords of SCI mouse model. LPS treatment led to elevation of SNHG1 expression in BV2 cells, as well as accelerated apoptosis and inflammation. Evident mitigation of LPS-induced BV2 cell damage was observed after SNHG1 knockdown. MiR-195-5p was identified as a target of SNHG1. Inhibition of miR-195-5p restored the impact of SNHG1 knockdown on cell damage of LPS-treated BV2 cells. Furthermore, miR-195-5p can target activating transcription factor-6 (ATF6). In summary, SNHG1 knockdown ameliorates LPS-induced microglial apoptosis and inflammatory response via the miR-195-5p/ATF6 axis, providing a novel direction for SCI treatment.

Abstract 1552: Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation

Abstract hosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN’s downregulation have remained elusive. In this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary basal muscle invasive BC (BMIBC) accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN poly-ubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorage-independent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice.Our findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation. Citation Format: Chuanshu Huang, Tengda Li, Honglei Jin. Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1552.

Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation

BackgroundPhosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN’s downregulation have remained elusive.MethodsWe established targeted genes’ knockdown or overexpressed cell lines to explore the mechanism how it drove the malignant transformation of urothelial cells or promoted anchorageindependent growth of human basal muscle invasive BC (BMIBC) cells. The mice model was used to validate the conclusion in vivo. The important findings were also extended to human studies.ResultsIn this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary BMIBC accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN polyubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorageindependent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice.ConclusionsOur findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation.

Coptisine prevents angiotensin II‑induced endothelial cell injury and senescence via the lncRNA SNHG12/miR‑603/NAMPT pathway.

Atherosclerosis (AS) is a major health problem and targeting the associated molecular pathways is critical for developing therapies. The present study investigated the effect of coptisine on human umbilical vein endothelial cells (HUVECs) in response to angiotensin II (Ang II) induction by focusing on cellular senescence, apoptosis and inflammation. HUVECs were treated with different Ang II concentrations and long non-coding RNA small nucleolar RNA host gene 12 (SNHG12), microRNA (miRNA/miR)-603 and nicotinamide phosphoribosyltransferase (NAMPT) expressions were assessed. Cell viability, nicotinamide adenine dinucleotide (NAD+) levels, senescence, apoptosis and inflammation were assessed. The interactions among SNHG12, miR-603 and NAMPT were investigated using dual-luciferase reporter gene assays and RNA pull-down experiments. Coptisine treatment increased SNHG12 expression and attenuated Ang II-induced adverse effects in HUVECs. SNHG12 silencing abrogated coptisine's protective effects, indicating that SNHG12 is a key mediator. SNHG12 targets miR-603, which then directly targets NAMPT, an age-related gene involved in NAD(+) regulation. Coptisine modulated the SNHG12/miR-603/NAMPT pathway and miR-603 inhibition enhanced the protective effects of coptisine. NAMPT overexpression reversed the negative effects of miR-603 and enhanced the protective effect of the miR-603 inhibitor. Finally, the protective mechanism of coptisine is linked to the regulation of NAD(+), sirtuin 3 (SIRT3) and p53. Coptisine treatment counteracted the AngII-induced increase in SIRT3 and p53 protein levels, whereas the miR-603 inhibitor potentiated the effect of coptisine. SNHG12 knockdown partially abolished these effects, which were reversed by NAMPT overexpression. In conclusion, the present study revealed a novel protective mechanism involving the SNHG12/miR-603/NAMPT pathway in HUVECs exposed to Ang II, highlighting the potential therapeutic application of coptisine in treating atherosclerosis. These results suggested that coptisine exerts its protective effects by modulating the SNHG12/miR-603/NAMPT axis, which ultimately affects the regulation of NAD(+), SIRT3 and p53. Future studies should explore the potential of the SNHG12/miR-603/NAMPT pathway as a target for developing novel AS therapies.

METTL3 promotes proliferation and migration of colorectal cancer cells by increasing SNHG1 stability.

N6‑methyladenosine (m6A) serves an essential role in RNA modulation and is implicated in multiple malignancies, including colorectal cancer (CRC). Methyltransferase‑like 3 (METTL3) is an important writer in m6A modification, however its role in CRC in modifying small nucleolar RNA host gene 1 (SNHG1), an oncogenic long noncoding RNA, remains unclear. In the present study, METTL3 expression in CRC was assessed using online bioinformatics analysis, immunohistochemistry staining, western blotting, reverse transcription (RT)‑quantitative PCR (qPCR) and cell transfections. Cell proliferation, migration and invasion were determined using functional Cell Counting Kit‑8 (CCK‑8) and Transwell assays. SNHG1 expression in CRC was evaluated using online bioinformatics analysis and RT‑qPCR. Methylated RNA immunoprecipitation qPCR was performed to assess m6A modification changes of SNHG1 mRNA. The present study demonstrated that METTL3 is upregulated in CRC tissues and cell lines. Moreover, METTL3 expression was associated with several unfavourable clinical features in patients with CRC, including the stage of lymph node metastases and overall survival. Functional Transwell and CCK‑8 assays demonstrated that knockdown of METTL3 suppressed CRC cell proliferation and migration. Furthermore, METTL3 was positively correlated with SNHG1 in CRC tissue, as indicated by analysis of data from The Cancer Genome Atlas. Mechanistically, SNHG1 contains 18 m6A modification sites. Through cell transfectionsand actinomycin D assays, the present study found that METTL3‑mediated m6A modification at these sites enhances the stability of SNHG1 in CRC cells. Finally, it was demonstrated that SNHG1 knockdown partially diminished the facilitative effect of METTL3 on CRC cell migration and proliferation. The present study concluded that METTL3, a potential biomarker for assessing overall survival and metastasis in CRC, may serve as an oncogene, promote SNHG1 m6A modification, improve the stability of SNHG1 and enhance SNHG1‑mediated oncogenic function in CRC.

Super-enhancer-associated SNHG15 cooperating with FOSL1 contributes to bladder cancer progression through the WNT pathway

Small nucleolar RNA host gene 15 (SNHG15) plays an oncogenic role in many cancers. However, the role of SNHG15 in bladder cancer (BLCA) remains unclear. In this study, the regulation of SNHG15 on the activities of BLCA cells (T24 and RT112) was investigated. In detail, super-enhancers (SEs), differentially expressed genes, and functional enrichment were detected by bioinformatic analyses. Mutant cell lines lacking SNHG15-SEs were established using CRISPR-Cas9. Relative gene expression was detected by quantitative polymerase chain reaction (qPCR), western blot, in situ hybridization, and immunohistochemistry assays. Cell senescence, apoptosis, viability, and proliferation were measured. Chromatin immunoprecipitation (ChIP)-qPCR and luciferase reporter gene assays were conducted to analyze the interactions between genes. A novel super-enhancer of SNHG15 (SNHG15-SEs) was discovered in several BLCA datasets. The deletion of SNHG15-SEs resulted in a significant downregulation of SNHG15. Mechanistically, the core active region of SNHG15-SEs recruited the transcription factor FOSL1 to facilitate the SNHG15 transcription, thereby inducing the proliferation and metastasis of BLCA cells. Deletion of SNHG15-SEs inhibited the growth and metastasis of T24 and RT112 cells by inactivating the WNT/CTNNB1 pathway activation. Overexpression of FOSL1 in SNHG15-SEs restored the cell proliferation and metastasis. Next, a xenograft mouse model showed that SNHG15-SEs deletion inhibited the proliferation and metastasis of BLCA cells in vivo. Collectively, our data indicate that SNHG15-SEs recruit FOSL1 to promote the expression of SNHG15 which interacts with CTNNB1 in the nucleus to activate the transcription of ADAM12, leading to the malignance of BLCA cells.

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.

Evaluating the effects of chemotherapy drugs and thiosemicarbazone complexes on the alteration of SNHG16 expression in Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is a malignant disease that afflicts both children and adults. It starts from the bone marrow (soft and spongy tissue inside the bone) where immature white blood cells or lymphocytes are formed. This study aims to compare chemotherapy drugs, methotrexate (MTX), cyclophosphamide, cytarabine (Ara-C) and mercaptopurine (6mp) with nickel (Ni) and copper (Cu) complexes of thiosemicarbazone (TSCZ) in terms of their effects on the changes of Small Nucleolar RNA Host Gene 16(SNHG16) long non coding RNA (lncRNA) expression in the ALL cell line.
 Materials and Methods: this experimental study was conducted on various concentrations of chemotherapy drugs including MTX, CP, Ara-C, 6mp and Ni and Cu complexes of TSCZ. The Jurkat E6.1 cell lines were subjected to passage in different groups and times (24, 48, and 72h) and then treated with the chemotherapy drugs. After RNA extraction and cDNA synthesis, the SNHG16 gene expression was evaluated by Real-Time PCR, and the results were analyzed by the Rest software.
 Results: As the results indicated, within 24h, MTX (0.77, 0.72), CP (0.61, 0.7), ara-C (0.78, 0.87), Cu (0.91, 0.95) and Ni (0.94, 0.79) complexes as well as complex 1(0.73) and 2 (0.94) decreased the expression of SNHG16 gene significantly (P<0.001). Furthermore within 48h, under the influence of CP (0.86, 0.89) and Ara-C (0.94, 0.97) as well as Cu (0.96) and Ni (0.98) complexes, the gene expression continued to decline(P<0.001).The greatest effect of chemotherapy drugs belonged to the combination of 1μM of ara-C and 5μM of 6mp.(P<0.001). 
 Conclusion: It was found that gene expression analysis is a feasible method to identify the pathways affected by the standard induction chemotherapy in ALL patients. This finding promotes the development of novel targeted drugs and biomarkers to categorize disease aggressiveness and evaluate treatment responses.

LncSNHG3 drives breast cancer progression by epigenetically increasing CSNK2A1 expression level.

Mounting evidence demonstrates that long noncoding RNAs (lncRNAs) have critical roles in the initiation and progression of cancer. Here, we report that small nucleolar RNA host gene 3 (SNHG3) is a key regulator of breast cancer progression. We analyzed RNA sequencing data to explore abnormally expressed lncRNAs in breast cancer. The effects of SNHG3 on breast cancer were investigated via in vitro and in vivo assays (CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, xenograft model, immunohistochemistry, and Western blot). The mechanism of SNHG3 action was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay and RNA immunoprecipitation assay. We found that SNHG3 expression was upregulated in breast cancer tissues and that its high expression level was associated with poor survival. We also found that high SNHG3 expression was partly induced by STAT3. Moreover, SNHG3 knockdown significantly repressed breast cancer cell growth both in vitro and in vivo. In the cytoplasm, SNHG3 facilitated the expression of Casein kinase II-A1 (CSNK2A1) by absorbing miR-485-5p and recruiting the HuR protein, participating in the malignant progression of breast cancer. Taken together, our study reveals a SNHG3-based regulatory network, which plays an oncogenic role in breast cancer and suggests that SNHG3 may serve as a potential target for the diagnosis and treatment of breast cancer.

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.

SNHG15 promotes chemoresistance and glycolysis in colorectal cancer.

Long noncoding RNAs (lncRNAs) play an important role in tumor progression. Small nucleolar RNA host gene 15 (SNHG15) is a lncRNA that has been confirmed to play an oncogenic role in multiple cancer types. However, its role in glycolysis and chemoresistance in colorectal cancer (CRC) is unclear. The expression of SNHG15 in CRC was analyzed using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases by bioinformatics methods. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to evaluate cell viability. Cell sensitivity to 5-fluorouracil (5-FU) was detected by CCK-8. Glucose absorption and lactate production were used to evaluate the impact of SNHG15 on glycolysis. RNA-seq, real-time fluorescence quantitative reverse transcription PCR (RT-qPCR) and Western blotting (WB) were used to reveal the potential molecular mechanism of SNHG15 in CRC. SNHG15 was upregulated in CRC tissues compared with paired noncancerous tissues. Ectopic SNHG15 expression increased proliferation, 5-FU chemoresistance, and glycolysis in CRC cells. In contrast, SNHG15 knockdown inhibited CRC proliferation, 5-FU chemoresistance and glycolysis. Multiple pathways, including apoptosis and glycolysis, were potentially regulated by SNHG15 based on RNA-seq and pathway enrichment analyses. RT-qPCR and WB experiments confirmed that SNHG15 promoted the expression of TYMS, BCL2, GLUT1 and PKM2 in CRC cells. In conclusion, SNHG15 promotes 5-FU chemoresistance and glycolysis in CRC by potentially regulating the expression of TYMS, BCL2, GLUT1 and PKM2 and appears to be a new target for cancer therapy.

SNHG1, a KLF4-upregulated gene, promotes glioma cell survival and tumorigenesis under endoplasmic reticulum stress by upregulating BIRC3 expression.

Increasing evidence indicates that long noncoding RNAs (lncRNAs) play crucial roles in the resistance to endoplasmic reticulum (ER) stress in many cancers. However, ER stress-regulated lncRNAs are still unknown in glioma. In the present study, we investigated the altered lncRNAs upon ER stress in glioma and found that small nucleolar RNA host gene 1 (SNHG1) was markedly increased in response to ER stress. Increased SNHG1 suppressed ER stress-induced apoptosis and promoted tumorigenesis in vitro and in vivo. Further mechanistic studies indicated that SNHG1 elevated BIRC3 mRNA stability and enhanced BIRC3 expression. We also found that KLF4 transcriptionally upregulated SNHG1 expression and contributed to the ER stress-induced SNHG1 increase. Collectively, the present findings indicated that SNHG1 is a KLF4-regulated lncRNA that suppresses ER stress-induced apoptosis and facilitates gliomagenesis by elevating BIRC3 expression.