Long noncoding RNA SNHG7 promotes the progression and growth of glioblastoma via inhibition of miR-5095

Immunological processes of enhancers and suppressors of long non-coding RNAs associated with brain tumors and inflammation

Immunological processes, such as inflammation, can both cause tumor suppression and cancer progression. Moreover, deregulated levels of long non-coding RNA (lncRNA) expression in the brain may cause inflammation and lead to the growth of tumors. Like other biological processes, the immune system's role in cancer is complicated, varies, and can help or hurt the cancer's maintenance. According to research, inflammation and brain cancer are correlated via several signaling pathways. A variety of lncRNAs have recently been revealed to influence cancer by modulating inflammatory pathways. As a result, lncRNAs have the potential to influence carcinogenesis, tumor formation, or tumor suppression via an increase or decrease in inflammation functions. Although the study and targeting of lncRNAs have made great progress in the treatment of cancer, there are definitely limitations and challenges. Using new technologies like nanocarriers and cell-penetrating peptides (CPPs) to target treatments without hurting healthy body tissues has shown to be very effective. In this review article, we have collected significantly related lncRNAs and their inhibitory or stimulating roles in inflammation and brain cancer for the first time. However, there are limitations, such as side effects and damage to normal tissues. With the advancement of new targeting technologies, these lncRNAs may be candidates for the specific targeting therapy of brain cancers by limiting inflammation or stimulating the immune system against them in the future.

Uveal melanoma immunogenomics predict immunotherapy resistance and susceptibility

Immune checkpoint inhibition has shown success in treating metastatic cutaneous melanoma but has limited efficacy against metastatic uveal melanoma, a rare variant arising from the immune privileged eye. To better understand this resistance, we comprehensively profile 100 human uveal melanoma metastases using clinicogenomics, transcriptomics, and tumor infiltrating lymphocyte potency assessment. We find that over half of these metastases harbor tumor infiltrating lymphocytes with potent autologous tumor specificity, despite low mutational burden and resistance to prior immunotherapies. However, we observe strikingly low intratumoral T cell receptor clonality within the tumor microenvironment even after prior immunotherapies. To harness these quiescent tumor infiltrating lymphocytes, we develop a transcriptomic biomarker to enable in vivo identification and ex vivo liberation to counter their growth suppression. Finally, we demonstrate that adoptive transfer of these transcriptomically selected tumor infiltrating lymphocytes can promote tumor immunity in patients with metastatic uveal melanoma when other immunotherapies are incapable.

A comprehensive insight into the role of small nucleolar RNAs (snoRNAs) and SNHGs in human cancers

Long non-coding RNAs (lncRNAs), which comprise most non-coding RNAs (ncRNAs), have recently become a focus of cancer research. How many functional ncRNAs exist is still a matter of debate. Although insufficient evidence supports that most lncRNAs function as transcriptional by-products, it is widely known that an increasing number of lncRNAs play essential roles in cells. Small nucleolar RNAs (snoRNAs), 60-300 nucleotides in length, have been better studied than long non-coding RNAs (lncRNAs) and are predominantly present in the nucleolus. Most snoRNAs are encoded in introns of protein- and non-protein-coding genes called small nucleolar RNA host genes (SNHGs). In this article, we explore the biology and characteristics of SNHGs and their role in developing human malignancies. In addition, we provide an update on the ability of these snoRNAs to serve as prognostic and diagnostic variables in various forms of cancer.

Role of Long Non-Coding RNA in Regulating ER Stress Response to the Progression of Diabetic Complications

Chronic hyperglycemia damages the nerves and blood vessels, culminating in other vascular complications. Such complications enhance cytokine, oxidative and endoplasmic reticulum (ER) stress. ER is the primary organelle where proteins are synthesised and attains confirmatory changes before its site of destination. Perturbation of ER homeostasis activates signaling sensors within its lumen, the unfolded protein response (UPR) that orchestrates ER stress and is extensively studied. Increased ER stress markers are reported in diabetic complications in addition to lncRNA that acts as an upstream marker inducing ER stress response. This review focuses on the mechanisms of lncRNA that regulate ER stress markers, especially during the progression of diabetic complications. Through this systemic review, we showcase the dysfunctional lncRNAs that act as a leading cause of ER stress response to the progression of diabetic complications.

Particulate Matters Affecting lncRNA Dysregulation and Glioblastoma Invasiveness: In Silico Applications and Current Insights

With a reported rise in global air pollution, more than 50% of the population remains exposed to toxic air pollutants in the form of particulate matters (PMs). PMs, from various sources and of varying sizes, have a significant impact on health as long-time exposure to them has seen a correlation with various health hazards and have also been determined to be carcinogenic. In addition to disrupting known cellular pathways, PMs have also been associated with lncRNA dysregulation-a factor that increases predisposition towards the onset or progression of cancer. lncRNA dysregulation is further seen to mediate glioblastoma multiforme (GBM) progression. The vast array of information regarding cancer types including GBM and its various precursors can easily be obtained via innovative in silico approaches in the form of databases such as GEO and TCGA; however, a need to obtain selective and specific information correlating anthropogenic factors and disease progression-in the case of GBM-can serve as a critical tool to filter down and target specific PMs and lncRNAs responsible for regulating key cancer hallmarks in glioblastoma. The current review article proposes an in silico approach in the form of a database that reviews current updates on correlation of PMs with lncRNA dysregulation leading to GBM progression.

Long noncoding RNA SNHG7-miRNA-mRNA axes crosstalk with oncogenic signaling pathways in human cancers

LncRNAs and miRNAs are the two most important non-coding RNAs, which have been identified to be associated with cancer progression or prevention. The dysregulation of lncRNAs conducts tumorigenesis and metastasis in different ways. One of the mechanisms is that lncRNAs interact with miRNAs to regulate distinct cellular and genomic processes and cancer progression. LncRNA SNHG7 as an oncogene sponges miRNAs and develops lncRNA-miRNA-mRNA axes, leading to the regulation of several signaling pathways such as Wnt/β-Catenin, PI3K/AKT/mTOR, SIRT1, and Snail-EMT. Therefore, in this article, after a brief overview of lncRNA SNHG7-miRNA-mRNA axes' contribution to cancer development, we will discuss the role of lncRNA SNHG7 in the genes expression and signaling pathways related to cancers development via acting as a ceRNA.

MicroRNAs influence and longevity

Background

MiRNAs play critical roles in the regulation of cellular function, life span, and the aging process. They can affect longevity positively and negatively through different aging pathways.

Main text

MiRNAs are a group of short non-coding RNAs that regulate gene expressions at post-transcriptional levels. The different types of alterations in miRNAs biogenesis, mRNA expressions, and activities of miRNA-protein complexes can affect the regulation of normal post-transcriptional gene process, which may lead to aging, age-related diseases, and an earlier death. It seems that the influence of deregulation of miRNAs on senescence and age-related diseases occurring by targeting aging molecular pathways can be used for diagnosis and prognosis of them. Therefore, the expression and function of miRNAs should be studied more accurately with new applicable and validated experimental tools. However, the current review wishes to highlight simply a connection among miRNAs, senescence and some age-related diseases.

Conclusion

Despite several research indicating the key roles of miRNAs in aging and longevity, further investigations are still needed to elucidate the essential roles of miRNAs in controlling mRNA regulation, cell proliferation, death and/or protection during stress and health problems. Besides, more research on miRNAs will help to identify new targets for alternative strategies regarding effectively screen, treat, and prevent diseases as well as make slow the aging process.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

LncRNA SNHG7 Promotes the HCC Progression Through miR-122-5p/FOXK2 Axis

Hepatocellular carcinoma (HCC) is a malignant tumor with high mortality and severe complication in China. Numerous studies have shown that long noncoding RNAs (lncRNAs) are involved in the regulation of various processes in cancer cells. Our research aimed to investigate the underlying mechanism of the lncRNA small nucleolar RNA host gene 7 (SNHG7) in HCC development. The expression of SNHG7, microRNA-122-5p (miR-122-5p), and Forkhead box K2 (FOXK2) was assessed via quantitative real-time polymerase chain reaction. 3-(4,5) -dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) and transwell assays were performed to measure cell viability, migration, and invasion, respectively. The relative protein levels were detected by Western blot. The relationships between miR-122-5p and SNHG7 or FOXK2 were predicted by online software and then confirmed by dual-luciferase reporter assay. Animal experiments were conducted to clarify the effects of SNHG7 on proliferation in vivo. To begin with, SNHG7 was upregulated, while miR-122-5p was downregulated in HCC tissues and cells. Downregulation of SNHG7 inhibited cell growth and metastasis. Interestingly, SNHG7 could abolish the effects of miR-122-5p on HCC cells. Furthermore, miR-122-5p targeted FOXK2 and miR-122-5p recovered the effects of FOXK2 downregulation on cell growth and metastasis in HCC cells. Besides, SNHG7 facilitated HCC tumor growth in vivo through the miR-122-5p/FOXK2 axis. The lncRNA SNHG7 boosted the development of HCC by regulating FOXK2 through sponging miR-122-5p.

Wnt and PI3K/Akt/mTOR Survival Pathways as Therapeutic Targets in Glioblastoma

Glioblastoma (GBM) is a devastating type of brain tumor, and current therapeutic treatments, including surgery, chemotherapy, and radiation, are palliative at best. The design of effective and targeted chemotherapeutic strategies for the treatment of GBM require a thorough analysis of specific signaling pathways to identify those serving as drivers of GBM progression and invasion. The Wnt/β-catenin and PI3K/Akt/mTOR (PAM) signaling pathways are key regulators of important biological functions that include cell proliferation, epithelial–mesenchymal transition (EMT), metabolism, and angiogenesis. Targeting specific regulatory components of the Wnt/β-catenin and PAM pathways has the potential to disrupt critical brain tumor cell functions to achieve critical advancements in alternative GBM treatment strategies to enhance the survival rate of GBM patients. In this review, we emphasize the importance of the Wnt/β-catenin and PAM pathways for GBM invasion into brain tissue and explore their potential as therapeutic targets.

Oncogenic Roles of Small Nucleolar RNA Host Gene 7 (SNHG7) Long Noncoding RNA in Human Cancers and Potentials

Long noncoding RNAs (lncRNAs) are a class of noncoding transcripts characterized with more than 200 nucleotides of length. Unlike their names, some short open reading frames are recognized for them encoding small proteins. LncRNAs are found to play regulatory roles in essential cellular processes such as cell growth and apoptosis. Therefore, an increasing number of lncRNAs are identified with dysregulation in a wide variety of human cancers. SNHG7 is an lncRNA with upregulation in cancer cells and tissues. It is frequently reported with potency of promoting malignant cell behaviors in vitro and in vivo. Like oncogenic/tumor suppressor lncRNAs, SNHG7 is found to exert its tumorigenic functions through interaction with other biological substances. These include sponging target miRNAs (various numbers are identified), regulation of several signaling pathways, transcription factors, and effector proteins. Importantly, clinical studies demonstrate association between high SNHG7 expression and clinicopathological features in cancerous patients, worse prognosis, and enhanced chemoresistance. In this review, we summarize recent studies in three eras of cell, animal, and human experiments to bold the prognostic, diagnostic, and therapeutic potentials.

Prognostic effect of lncRNA SNHG7 on cancer outcome: a meta and bioinformatic analysis

BACKGROUND

New evidence from clinical and fundamental researches suggests that SNHG7 is involved in the occurrence and development of carcinomas. And the increased levels of SNHG7 are associated with poor prognosis in various kinds of tumors. However, the small sample size was the limitation for the prognostic value of SNHG7 in clinical application. The aim of the present meta-analysis was to conduct a qualitative analysis to explore the prognostic value of SNHG7 in various cancers.

METHODS

Articles related to the SNHG7 as a prognostic biomarker for cancer patients, were comprehensive searched in several electronic databases. The enrolled articles were qualified via the preferred reporting items for systematic reviews and meta-analysis of observational studies in epidemiology checklists. Additionally, an online database based on The Cancer Genome Atlas (TCGA) was further used to validate our results.

RESULTS

We analyzed 2418 cancer patients that met the specified criteria. The present research indicated that an elevated SNHG7 expression level was significantly associated with unfavorable overall survival (OS) (HR = 2.45, 95% CI: 2.12-2.85, p <0.001). Subgroup analysis showed that high expression levels of SNHG7 were also significantly associated with unfavorable OS in digestive system cancer (HR = 2.31, 95% CI: 1.90-2.80, p <0.001) and non-digestive system cancer (HR = 2.67, 95% CI: 2.12-3.37, p <0.001). Additionally, increased SNHG7 expression was found to be associated with tumor stage and progression (III/IV vs. I/II: HR = 1.76, 95% CI: 1.57-1.98, p <0.001). Furthermore, elevated SNHG7 expression significantly predicted lymph node metastasis (LNM) (HR = 1.98, 95% CI: 1.74-2.26, p <0.001) and distant metastasis (DM) (HR = 2.49, 95% CI: 1.88-3.30, p <0.001) respectively. No significant heterogeneity was observed among these studies. SNHG7 was significantly upregulated in four cancers and the elevated expression of SNHG7 predicted shorter OS in four cancers, worse DFS in five malignancies and worse PFI in five carcinomas based on the validation using the GEPIA on-line analysis tool.

CONCLUSIONS

The present analysis suggests that elevated SNHG7 is significantly associated with unfavorable OS, tumor progression, LNM and DM in various carcinomas, and may be served as a promising biomarker to guide therapy for cancer patients.

Is Long Noncoding SNHG7 a Reliable Diagnostic Tool for Metastasis Diagnosis of Cancer: A Meta-Analysis

Background: The small nucleolar RNA host gene 7 (SNHG7) has been suggested as a biomarker of metastatic cancer; however, its reliability is controversial. Therefore, the goal of this study was to conduct a meta-analysis to assess the reliability of SNHG7 as a comprehensive cancer metastasis diagnostic biomarker. Methods: A comprehensive literature search was conducted using PubMed, Cochrane Library, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) to identify articles which examined the role of SNHG7 in cancers. Random-effects models and fixed-effects models were conducted to estimate the pooled odds ratios (ORs) for the associations of SNHG7 with distant metastases and lymph node metastases. Hierarchical summary receiver operating characteristic (ROC) models were used to estimate the sensitivity and specificity of SNHG7 as a biomarker for cancer metastasis diagnoses. Results: Nineteen studies comprised 1491 patients were included in this meta-analysis. We found that both distant metastasis (OR = 4.19, 95% confidence interval [CI] = 2.93-5.99, I² = 34%) and lymph node metastasis (OR = 3.07, 95% CI = 1.65-5.68, I² = 79.03%) were significantly associated with a higher expression of SNHG7. We also showed a pooled sensitivity and specificity of 74% (95% CI = 66-82) and 57% (95% CI = 53-61) for distant metastasis; as well as 72% (95% CI = 63-80) and 54% (95% CI = 46-63) for lymph node metastasis, respectively. Conclusion: Our findings suggest that SNHG7 is a potential diagnostic biomarker for metastasis of cancer; however, its clinical application requires stronger evidence due to the low sensitivity and specificity. Further larger-scale studies from diverse settings and cancer types will be necessary to reveal novel insights into SNHG7 as a biomarker for cancer metastasis diagnoses.

Long non-coding RNA (LncRNA) SNHG7/ Eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) involves in the malignant events of ovarian cancer cells with paclitaxel resistant

LncRNA SNHG7 shows a strong relationship with malignant behavior of cancer cells and poor clinical outcome in cancer. The resistance of ovarian cancer for Paclitaxel seriously limits the clinical efficacy in chemotherapy for ovarian cancer patients. In this study, we investigated whether lncRNA SNHG7 was involved in Paclitaxel sensitivity of ovarian cancer as well as the underlying mechanism regulating the behavior of ovarian cancer cells with Paclitaxel resistance. The experiment results of wound healing and transwell showed that in paclitaxel-resistant ovarian cancer cells, transfection with siRNA-SNHG7 in ovarian cancer cells reduced cell migration and invasion. And cell cycle was observed by means of Flow cytometry. RNA immunoprecipitation assay was performed to analyze the interaction of lncRNA SNHG7 and EIF4G2. Overexpression of EIF4G2 by transfection with Ov- EIF4G2 plasmids efficiently blocked the changes of migration and invasion, as well as G0/1 arrest caused by lncRNA SNHG7 silencing. Taken together, these results demonstrated that lncRNA SNHG7 could affect the degradation of EIF4G2 to regulate the sensitivity of ovarian cancer to Paclitaxel, inhibit cell viability, migration, and invasion. The interaction of lncRNA SNHG7 and EIF4G2 plays an important role in the migrative and invasive activity and Paclitaxel resistance of ovarian cancer cells.

Regulatory interplay between microRNAs and WNT pathway in glioma

Glioma is one of the most common neoplasms of the central nervous system with a poor survival. Due to the obstacles in treating this disease, a part of recent studies mainly focuses on identifying the underlying molecular mechanisms that contribute to its malignancy. Altering microRNAs (miRNAs) expression pattern has been identified obviously in many cancers. Through regulating various targets and signaling pathways, miRNAs play a pivotal role in cancer progression. As one of the essential signaling pathways, WNT pathway is dysregulated in many cancers, and a growing body of evidence emphasis its dysregulation in glioma. Herein, we provide a comprehensive review of miRNAs involved in WNT pathway in glioma. Moreover, we show the interplay between miRNAs and WNT pathway in regulating different processes such as proliferation, invasion, migration, radio/chemotherapy resistance, and epithelial-mesenchymal-transition. Then, we introduce several drugs and treatments against glioma, which their effects are mediated through the interplay of WNT pathway and miRNAs.

Metastasis associated long noncoding RNAs in glioblastoma: Biomarkers and therapeutic targets

Glioblastoma (GBM) is the most aggressive, malignant, and therapeutically challenging Grade IV tumor of the brain. Although the possibility of distant metastasis is extremely rare, GBM is known to cause intracranial metastasis forming aggressive secondary lesions resulting in a dismal prognosis. Metastasis also plays an important role in tumor dissemination and recurrence making GBM largely incurable. Recent studies have indicated the importance of long noncoding RNAs (lncRNAs) in GBM metastasis. lncRNAs are a class of regulatory noncoding RNAs (>200 nt) that interact with DNA, RNA, and proteins to regulate various biological processes. This is the first comprehensive review summarizing the lncRNAs associated with GBM metastasis and the underlying molecular mechanism involved in migration/invasion. We also highlight the complex network of lncRNA/miRNA/protein that collaborate/compete to regulate metastasis-associated genes. Many of these lncRNAs also show attractive potential as diagnostic/prognostic biomarkers. Finally, we discuss various therapeutic strategies and potential applications of lncRNAs as therapeutic targets for the treatment of GBM.

Targeting Non-coding RNA for Glioblastoma Therapy: The Challenge of Overcomes the Blood-Brain Barrier

Glioblastoma (GBM) is the most malignant form of all primary brain tumors, and it is responsible for around 200,000 deaths each year worldwide. The standard therapy for GBM treatment includes surgical resection followed by temozolomide-based chemotherapy and/or radiotherapy. With this treatment, the median survival rate of GBM patients is only 15 months after its initial diagnosis. Therefore, novel and better treatment modalities for GBM treatment are urgently needed. Mounting evidence indicates that non-coding RNAs (ncRNAs) have critical roles as regulators of gene expression. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are among the most studied ncRNAs in health and disease. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Several dysregulated miRNAs and lncRNAs have been identified in GBM cell lines and GBM tumor samples. Some of them have been proposed as diagnostic and prognostic markers, and as targets for GBM treatment. Most ncRNA-based therapies use oligonucleotide RNA molecules which are normally of short life in circulation. Nanoparticles (NPs) have been designed to increase the half-life of oligonucleotide RNAs. An additional challenge faced not only by RNA oligonucleotides but for therapies designed for brain-related conditions, is the presence of the blood-brain barrier (BBB). The BBB is the anatomical barrier that protects the brain from undesirable agents. Although some NPs have been derivatized at their surface to cross the BBB, optimal NPs to deliver oligonucleotide RNA into GBM cells in the brain are currently unavailable. In this review, we describe first the current treatments for GBM therapy. Next, we discuss the most relevant miRNAs and lncRNAs suggested as targets for GBM therapy. Then, we compare the current drug delivery systems (nanocarriers/NPs) for RNA oligonucleotide delivery, the challenges faced to send drugs through the BBB, and the strategies to overcome this barrier. Finally, we categorize the critical points where research should be the focus in order to design optimal NPs for drug delivery into the brain; and thus move the Oligonucleotide RNA-based therapies from the bench to the clinical setting.

lncRNA SNHG7 promotes cell proliferation in glioma by acting as a competing endogenous RNA and sponging miR-138-5p to regulate EZH2 expression

Glioma is the most common type of primary brain cancer in adults. Accumulating studies have reported that long non-coding RNAs (lncRNAs) serve a significant role in the initiation and development of glioma. lncRNA small nucleolar RNA host gene 7 (SNHG7) has been previously demonstrated to serve a role in numerous glioma biological processes, including cell proliferation, invasion and migration. The present study aimed to investigate the role of SNHG7 in glioma through reverse transcription-quantitative PCR, western blotting and cell function assays. The results revealed that SNHG7 expression was upregulated in glioma tissues and cell lines, while microRNA (miR)-138-5p expression was downregulated. Moreover, the knockdown of SNHG7 expression decreased the proliferation of glioma cells. Mechanistic studies demonstrated that SNHG7 downregulated miR-138-5p expression, which subsequently affected the expression levels of its target gene, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). In conclusion, the results of the present study suggested that SNHG7 may act as a competing endogenous RNA to sponge miR-138-5p and modulate EZH2 expression. Thus, SNHG7 may enhance glioma proliferation via modulating the miR-138-5p/EZH2 signaling axis.

Long non-coding RNA SNHG7 facilitates pancreatic cancer progression by regulating the miR-146b-5p/Robo1 axis

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 7 (SNHG7) plays a crucial role in the progression of pancreatic cancer (PC). SNHG7 is upregulated in PC; therefore, the purpose of the present study was to investigate the role and underlying mechanism of SNHG7 on PC progression. In the present study, the mRNA expression levels of SNHG7, microRNA(miR)-146b-5p and roundabout homolog 1 (Robo1) were measured via reverse transcription-quantitative PCR. Moreover, cell viability and apoptosis were assessed by MTT and flow cytometry assays, respectively. The ability of cells to migrate and invade was evaluated by Transwell assays. In addition, dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays were conducted to assess the interaction between miR-146b-5p and SNHG7 or Robo1. The protein expression of Robo1 was measured via western blotting. Furthermore, mouse xenograft models were established to further investigate the effect of SNHG7 on PC progression in vivo. The results indicated that SNHG7 was highly expressed in PC tissues and cells. It was also found that SNHG7 was sponged by miR-146b-5p and that Robo1 was a target of miR-146b-5p. Moreover, it was demonstrated that SNHG7 knockdown inhibited cell proliferation, migration and invasion, as well as tumorigenesis and apoptosis of PC cells in vitro and in vivo by regulating miR-146b-5p. The results also suggested that miR-146b-5p overexpression inhibited the progression of PC cells by modulating Robo1. Furthermore, silencing of SNHG7 downregulated Robo1 expression by sponging miR-146b-5p. Collectively, the present results indicate that SNHG7 promotes PC progression by sponging miR-146b-5p and upregulating Robo1.

MSC-derived exosomal lncRNA SNHG7 suppresses endothelial-mesenchymal transition and tube formation in diabetic retinopathy via miR-34a-5p/XBP1 axis

AIMS

Diabetic retinopathy (DR) is the most common complication of type 2 diabetes mellitus, which could result in visual impairment. Accumulating studies have shown the implication of long non-coding RNAs (lncRNAs) in the pathogenesis of DR. Our aims are to investigate whether lncRNA SNHG7 plays a role during DR pathogenesis.

MAIN METHODS

Human retinal microvascular endothelial cells (HRMECs) were treated with high glucose (HG) to build cell model. Relative expression of RNAs were examined using qPCR, and western blot or immunofluorescence analysis was adopted to detect the protein expression. Cell viability, migration and angiogenic capacity of HRMECs were estimated through CCK-8, transwell and tube formation experiments, respectively. Dual-luciferase reporter and RNA pull down assays were employed to verify the interplay between miR-34a-5p and SNHG7 or XBP1. Mesenchymal stem cells (MSCs) were identified by examining typical surface makers using flow cytometry and the differentiation abilities via Alizarin red, Oil red O and Alcian blue staining. MSC-derived exosomes were verified by transmission electron microscopy and western blot.

KEY FINDINGS

LncRNA SNHG7 sponged to and negatively regulated miR-34a-5p. SNHG7 overexpression repressed HG induced endothelial-mesenchymal transition (EndMT) and tube formation of HRMECs, while miR-34a-5p overexpression could reverse this effect. miR-34a-5p targeted and negative regulated XBP1. Knockdown of miR-34a-5p repressed HG induced EndMT and tube formation, which were partially blocked by XBP1 inhibition. MSC-derived exosomes could transfer SNHG7 to HRMECs and modulated EndMT and tube formation.

SIGNIFICANCE

The MSC-derived exosomal lncRNA SNHG7 suppresses EndMT and tube formation in HRMECs via miR-34a-5p/XBP1 axis.

LncRNA-SNHG7 interferes with miR-34a to de-sensitize gastric cancer cells to cisplatin

Gastric cancer (GC) remains poor prognosis and survival issues due to the resistance of chemotherapies, such as cisplatin. The long non-coding RNA small nucleolar RNA host gene 7 (lncRNA-SNHG7) is known as an oncogenic molecule in diverse cancers. Here, we demonstrate that SNHG7 was significantly upregulated in gastric cancer and positively correlated with cisplatin resistance of gastric cancer cells that SNHG7 was significantly upregulated in cisplatin resistant cells. Silencing SNHG7 dramatically sensitized cisplatin resistant cells. In contrast, a negative correlation between lncRNA-SNHG7 and miR-34a was found that miR-34a was downregulated in gastric cancer patient tissues and significantly sensitized cisplatin resistant gastric cancer cells. Intriguingly, bioinformatical analysis indicated miR-34a has putative biding site for SNHG7 and such negative association between SNHG7 and miR-34a was verified in gastric cancer tissues. The cisplatin resistant cells displayed increased glycolysis rate and SNHG7 promoted cellular glycolysis rate of gastric cancer cells. Luciferase assay illustrated LDHA, a glycolysis enzyme, was the direct target of miR-34a. Importantly, inhibiting SNHG7 successfully suppressed LDHA expressions and sensitized cisplatin resistant cells and such inhibitory effects could be recovered by further anti-miR-34a. These findings suggest an important regulator mechanism for the SNHG7-mediated cisplatin resistance via miR-34a/LDHA-glycolysis axis.

Emerging Role of Long Non-Coding RNAs in the Pathobiology of Glioblastoma

Glioblastoma is the utmost aggressive diffuse kind of glioma which is originated from astrocytes, neural stem cells or progenitors. This malignant tumor has a poor survival rate. A number of genetic aberrations and somatic mutations have been associated with this kind of cancer. In recent times, the impact of long non-coding RNAs (lncRNAs) in glioblastoma has been underscored by several investigations. Up-regulation of a number of oncogenic lncRNAs such as H19, MALAT1, SNHGs, MIAT, UCA, HIF1A-AS2 and XIST in addition to down-regulation of other tumor suppressor lncRNAs namely GAS5, RNCR3 and NBAT1 indicate the role of these lncRNAs in the pathogenesis of glioblastoma. Several in vitro and a number of in vivo studies have demonstrated the contribution of these transcripts in the regulation of cell proliferation and apoptosis, cell survival, invasion and metastasis of glioblastoma cells. Moreover, some lncRNAs such as SBF2-AS1 are involved in conferring resistance to temozolomide. Finally, few circularRNAs have been identified that influence the evolution of glioblastoma. In this paper, we discuss the impacts of lncRNAs in the pathogenesis of glioblastoma, their applications as markers and their implications in the therapeutic responses in this kind of cancer.

LncRNA SNHG7 Mediates the Chemoresistance and Stemness of Breast Cancer by Sponging miR-34a

Chemoresistance is considered to be a major cause of the recurrence and metastasis of breast cancer (BC). LncRNA SNHG7 has been reported to be upregulated in breast cancer and to promote tumor progression and metastasis. Nevertheless, the function and potential regulatory mechanism of SNHG7 in BC drug resistance are still largely unclear. This study indicated that SNHG7 was highly expressed in chemoresistant BC tissues and cells. Upregulated SNHG7 might predict a low pCR rate and poor clinical outcome in BC patients. Knockdown of SNHG7 enhanced drug sensitivity and drug-induced apoptosis in chemoresistant BC cells. In terms of the mechanism, miR-34a was found to be a target of SNHG7 and its expression in breast cancer tissues and chemoresistant cell lines was negatively correlated with SNHG7 expression. Importantly, sh-SNHG7 upregulated miR-34a expression, reduced the percentages of CD44⁺/CD24⁻cells, and inhibited sphere-formation and stem cell factor (Oct4, Nanog, SOX2) expression. Functional loss experiments showed that the repressive effect of SNHG7 knockdown on BC cell stemness was partially reversed by transfection with miR-34a inhibitors. In summary, this study indicated that SNHG7 contributed to the chemoresistance of BC and mediated chemoresistance and cancer stemness by sponging miR-34a.

Oncogenic roles of lncRNA BLACAT1 and its related mechanisms in human cancers

Long non-coding RNAs (lncRNAs) play indispensable roles in mediating regulation of epigenetics, and their dysregulation is strongly associated with the initiation and progression of human cancers. Recently, lncRNA bladder cancer-associated transcript 1 (BLACAT1) has been observed to exert oncogenic effects on cancers, including glioma, breast cancer, lung cancer, hepatocellular carcinoma, gastric cancer, colorectal cancer, ovarian cancer, cervical cancer and osteosarcoma. Additional mechanical analyses have uncovered that lncRNA BLACAT1 is positively correlated with tumor stage, lymph node metastasis and distant metastasis of primary tumors via involvement with various cellular activities, thus leading to poor overall survival and progression-free survival (PFS). In this review, we generalize the oncogenic roles of BLACAT1 in multiple human cancers through correlation with clinical implications and cellular activities. Moreover, we forecast its potential clinical application as a novel biomarker and a promising therapeutic target for cancers.

Long non-coding RNAs as epigenetic mediator and predictor of glioma progression, invasiveness, and prognosis

Gliomas are aggressive brain tumors with high mortality rate. Over the past several years, non-coding RNAs, specifically the long non-coding RNAs (lncRNAs), have emerged as biomarkers of considerable interest. Emerging data reveals distinct patterns of expressions of several lncRNAs in the glioma tissues, relative to their expression in normal brains. This has led to the speculation for putative exploitation of lncRNAs as diagnostic biomarkers as well as biomarkers for targeted therapy. With a focus on lncRNAs that have shown promise as epigenetic biomarkers in the proliferation, migration, invasion, angiogenesis and metastasis in various glioma models, we discuss several such lncRNAs. The data from cell line / animal model-based studies as well as analysis from human patient samples is presented for the most up-to-date information on the topic. Overall, the information provided herein makes a compelling case for further evaluation of lncRNAs in clinical settings.

The role of long noncoding RNA SNHG7 in human cancers (Review)

Long non-coding RNAs (lncRNAs) have been demonstrated to serve important roles in a variety of human tumor types. The lncRNA small nucleolar RNA host gene 7 (SNHG7) is associated with a variety of cancer types, such as esophageal cancer, breast cancer and gastric neoplasia. Based on previous studies that examined SNHG7 expression in tumors, it has become clear that SNHG7 modulates tumorigenesis and cancer progression by acting as a competing endogenous RNA. SNHG7 can sponge tumor-suppressive microRNAs and regulate downstream signaling pathways. In addition, overexpression of SNHG7 is associated with the clinical characteristics of patients with cancer by regulating cellular proliferation, invasion and metastasis and by inhibiting apoptosis via a variety of mechanisms of action. The function of SNHG7 in tumorigenesis and cancer progression indicates that it can potentially act as a novel therapeutic target or a diagnostic biomarker for cancer therapy or detection, respectively.

LncRNA SNHG7 promotes glioma cells viability, migration and invasion by regulating miR-342-3p/AKT2 axis

PURPOSE

Glioma has been categorized as the most common primary malignant brain tumor. Long non-coding RNA SNHG7 (lncRNA SNHG7) has been recognized in various cancers as a possible oncogene. In this study, the effect of SNHG7 on glioma cells was investigated.

MATERIALS AND METHODS

Thirty glioma tissues and adjacent normal tissues were collected. Pc-SNHG7, sh-SNHG7, miR-342-3p mimic and miR-342-3p inhibitor were transfected into the glioma cells. Cell Counting Kit-8, Transwell and scratch assay evaluated glioma cells viability, invasion and migration, respectively. TargetScan, Starbase and dual-luciferase reporter were used to predict and confirm the target genes and potential binding sites of SNHG7, miR-342-3p and AKT2. Relative miR-342-3p and AKT2 expressions were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Pearson's analysis was adopted for correlation analysis between SNHG7, miR-342-3p and AKT2.

RESULTS

SNHG7 expressions in glioma tissues and cells were increased, upregulation of SNHG7 promotes cell viability, invasion and migration. SNHG7 was shown to bind with miR-342-3p, and upregulating SNHG7 reduced miR-342-3p expression. AKT2 was the target gene of miR-342-3p, and miR-342-3p expression was decreased while AKT2 expression was increased in glioma tissues. High expression of miR-342-3p inhibited cell viability, invasion and migration and reduced AKT2 expression, whereas low expression of miR-342-3p did the opposite effect.

CONCLUSIONS

Upregulating SNHG7 might promote glioma cells viability, migration and invasion with the regulation of decreasing miR-342-3p level and increasing AKT2 level.

Current advances of long non-coding RNAs mediated by wnt signaling in glioma

Glioma is the most common and aggressive brain tumor in the central nervous system (CNS), in which Wnt signaling pathway has been verified to play a pivotal role in regulating the initiation and progression. Currently, numerous studies have indicated that long non-coding RNAs (lncRNAs) have critical functions across biological processes including cell proliferation, colony formation, migration, invasion and apoptosis via Wnt signaling pathway in glioma. This review depicts canonical and non-canonical Wnt/β-catenin signaling pathway properties and relative processing mechanisms in gliomas, and summarizes the function and regulation of lncRNAs mediated by Wnt signaling pathway in the development and progression of glioma. Ultimately, we hope to seek out promising biomarkers and reliable therapeutic targets for glioma.

Integrated analysis of lncRNA-associated ceRNA network identified potential regulatory interactions in osteosarcoma

This study aimed to identify potential therapeutic targets in osteosarcoma (OS) through the network analysis of competing endogenous RNAs (ceRNAs). The differentially expressed miRNAs (DEMIs) and mRNAs (DEMs) were identified between OS cell lines and human mesenchymal stem cells (hMSCs) from the data deposited under GSE70415 using limma package. Functional analysis of DEMs was performed using DAVID and clusterProfiler to identify significantly enriched Gene Ontology biological processes and KEGG pathways, respectively. The DEMI-DEM interaction network was constructed using Cytoscape. LncRNA-miRNA interactions were predicted using starBase database. The ceRNA regulatory network was constructed by integrating mRNAs, miRNAs, and lncRNAs, and functional enrichment analysis was performed for the genes involved. The analysis revealed a total of 326 DEMs and 54 DEMIs between OS cells and hMSCs. We identified several novel therapeutic targets involved in the progression and metastasis of OS, such as CBX7, RAD9A, SNHG7 and miR-34a-5p. The miRNA, miR-543 (target gene: CBX7) was found to be associated with the pathway Mucin type O-glycan biosynthesis. Using the ceRNA network, we established the following regulatory interactions: NEAT1/miR-543/CBX7, SNHG7/miR-34a-5p/RAD9A, and XIST/miR-34a-5p/RAD9A. CBX7, RAD9A, lncRNA SNHG7, miR-543, and miR-34a-5p may be explored as novel therapeutic targets for treatment of OS.

Long non-coding RNA SNHG7 inhibits NLRP3-dependent pyroptosis by targeting the miR-34a/SIRT1 axis in liver cancer

Long non-coding RNA small nucleolar RNA host gene 7 (SNHG7) is involved in a variety of different types of cancer; however, the role of SNHG7 during liver cancer progression is not completely understood. The aim of the present study was to investigate the functional role and regulatory mechanism underlying SNHG7 during liver cancer. A total of 25 paired hepatocellular carcinoma (HCC) tumor tissues and adjacent normal tissues were collected. Reverse transcription-quantitative PCR and western blotting were performed to detect the expression levels of SNHG7, microRNA (miR)-34a, sirtuin 1 (SIRT1) and pyroptosis-related targets. RNA fluorescence in situ hybridization was performed to detect the expression of SNHG7 in HCC tissues. SNHG7 expression was upregulated in HCC tissues and liver cancer cells compared with normal tissues and normal liver cell lines. High expression of SNHG7 inhibited NLR family pyrin domain containing 3 (NLRP3)-dependent pyroptosis in HepG2 and SK-hep-1 cells. Bioinformatics analysis and dual-luciferase reporter assays were performed to investigate the interactions between miR-34a and SNHG7 or SIRT1. SNHG7 served as a competing endogenous RNA of miR-34a, and SIRT1 was identified as a direct target of miR-34a. Cell pyroptosis was evaluated by TUNEL and lactate dehydrogenase release assays. SNHG7 knockdown reduced SIRT1 expression, but increased the expression levels of NLRP3, caspase-1 and interleukin-1β, leading to pyroptosis. SNHG7 knockdown-induced effects were enhanced by miR-34a upregulation. In summary, the present study indicated that the SNHG7/miR-34a/SIRT1 axis contributed to NLRP3-dependent pyroptosis during liver cancer.

SNHG7 Contributes to the Progression of Non-Small-Cell Lung Cancer via the SNHG7/miR-181a-5p/E2F7 Axis

Background

Non-small-cell lung cancer (NSCLC) is a common malignant tumor with very high mortality. Small nucleolar RNA host gene 7 (SNHG7) was associated with many tumors progression. We aimed to explore the role and regulatory mechanism of SNHG7 in the development of NSCLC.

Methods

The expression of SNHG7, miR-181a-5p and E2F transcription factor 7 (E2F7) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of E2F7 was evaluated by Western blot. Cell Counting Kit-8 (CCK-8) assay was conducted to explore cell proliferation. Flow cytometry was used to examine cell apoptosis. The clonogenic examination was performed to reflect cell population dependence and proliferative ability. Transwell assay was used to assess cell migration and invasion. The potential target relationship between miR-181a-5p and SNHG7 or E2F7 was analyzed by dual-luciferase reporter assay. A xenograft mouse model was generated to verify the effect of SNHG7 on tumor growth in vivo.

Results

SNHG7 and E2F7 were increased, while miR-181a-5p was decreased in NSCLC. Knockdown of SNHG7 suppressed cell viability, clonogenic, migration, invasion and tumor growth, and promoted cell apoptosis. SNHG7 acted as a sponge of miR-181a-5p and E2F7 was directly interacted with miR-181a-5p. Overexpression of miR-181a-5p had the same functional effect as SNHG7 knockdown on the progression of NSCLC cells. E2F7 was negatively correlated with miR-181a-5p and positively correlated with SNHG7. Moreover, miR-181a-5p inhibition or E2F7 overexpression abolished the effect of SNHG7 knockdown on the progression of NSCLC cells.

Conclusion

SNHG7 regulated the development of NSCLC cells by the miR-181a-5p/E2F7 axis.

Genome‑wide DNA methylation regulation analysis of long non‑coding RNAs in glioblastoma

Glioblastoma (GBM) is a malignant brain tumor associated with high mortality. Long non-coding RNAs (lncRNAs) are increasingly being recognized as its modulators. However, it remains mostly unexplored how lncRNAs are mediated by DNA methylation in GBM. The present study integrated multi-omics data to analyze the epigenetic dysregulation of lncRNAs in GBM. Widely aberrant methylation in the lncRNA promoters was observed, and the lncRNA promoters exhibited a more hypomethylated pattern in GBM. By combining transcriptional datasets, it was possible identify the lncRNAs whose transcriptional changes might be associated with the aberrant promoter methylation. Then, a methylation-mediated lncRNA regulatory network and functional enrichment analysis of aberrantly methylated lncRNAs showed that lncRNAs with different methylation patterns were involved in diverse GBM progression-related biological functions and pathways. Specifically, four lncRNAs whose increased expression may be regulated by the corresponding promoter hypomethylation were evaluated to have an excellent diagnostic effect and clinical prognostic value. Finally, through the construction of drug-target association networks, the present study identified potential therapeutic targets and small-molecule drugs for GBM treatment. The present study provides novel insights for understanding the regulation of lncRNAs by DNA methylation and developing cancer biomarkers in GBM.

An Emerging Class of Long Non-coding RNA With Oncogenic Role Arises From the snoRNA Host Genes

The small nucleolar RNA host genes (SNHGs) are a group of long non-coding RNAs, which are reported in many studies as being overexpressed in various cancers. With very few exceptions, the SNHGs (SNHG1, SNHG3, SNHG5, SNHG6, SNHG7, SNHG12, SNHG15, SNHG16, SNHG20) are recognized as inducing increased proliferation, cell cycle progression, invasion, and metastasis of cancer cells, which makes this class of transcripts a viable biomarker for cancer development and aggressiveness. Through our literature research, we also found that silencing of SNHGs through small interfering RNAs or short hairpin RNAs is very effective in both in vitro and in vivo experiments by lowering the aggressiveness of solid cancers. The knockdown of SNHG as a new cancer therapeutic option should be investigated more in the future.

lncRNA and mRNA signature for prognosis prediction of glioblastoma

Aims: We aimed to find out potential novel biomarkers for prognosis of glioblastoma (GBM). Materials & methods: We downloaded mRNA and lncRNA expression profiles of 169 GBM and five normal samples from The Cancer Genome Atlas and 129 normal brain samples from genotype-tissue expression. We use R language to perform the following analyses: differential RNA expression analysis of GBM samples using 'edgeR' package, survival analysis taking count of single or multiple gene expression level using 'survival' package, univariate and multivariate Cox regression analysis using Cox function plugged in 'survival' package. Gene ontology and Kyoto encyclopedia of genes and genomes pathway analysis were performed using FunRich tool online. Results and conclusion: We obtained differentially DEmRNAs and DElncRNAs in GBM samples. Most prognostically relevant mRNAs and lncRNAs were filtered out. 'GPCR ligand binding' and 'Class A/1' are found to be of great significance. In short, our study provides novel biomarkers for prognosis of GBM.

lncRNA SNHG11 promotes lung cancer cell proliferation and migration via activation of Wnt/β-catenin signaling pathway

Lung cancer ranks topmost among the most frequently diagnosed cancers. Despite increasing research, there are still unresolved mysteries in the molecular mechanism of lung cancer. Long noncoding RNA small nucleolar RNA host gene 11 (SNHG11) was found to be upregulated in lung cancer and facilitated lung cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition progression while suppressed cell apoptosis. Moreover, the high expression of SNHG11 was correlated with poor prognosis of lung cancer patients, TNM stage, and tumor size. Further assays demonstrated that SNHG11 functioned in lung cancer cells via Wnt/β-catenin signaling pathway. Subsequently, Wnt/β-catenin pathway was found to be activated through SNHG11/miR-4436a/CTNNB1 ceRNA axis. As inhibiting miR-4436 could only partly rescue the suppression of cell function induced by silencing SNHG11, it was suspected that β-catenin might enter cell nucleus through other pathways. Mechanism investigation proved that SNHG11 would directly bind with β-catenin to activate classic Wnt pathway. Subsequently, in vivo tumorigenesis was also demonstrated to be enhanced by SNHG11. Hence, SNHG11 was found to promote lung cancer progression by activating Wnt/β-catenin pathway in two different patterns, implying that SNHG11 might contribute to lung cancer treatment by acting as a therapeutic target.

Contributions of Gene Modules Regulated by Essential Noncoding RNA in Colon Adenocarcinoma Progression

Noncoding RNAs (ncRNAs), especially microRNA (miRNA) and long noncoding RNA (lncRNA), have an impact on a variety of important biological processes during colon adenocarcinoma (COAD) progression. This includes chromatin organization, transcriptional and posttranscriptional regulation, and cell-cell signaling. The aim of this study is to identify the ncRNA-regulated modules that accompany the progression of COAD and to analyze their mechanisms, in order to screen the potential prognostic biomarkers for COAD. An integrative molecular analysis was carried out to identify the crosstalks of gene modules between different COAD stages, as well as the essential ncRNAs in the posttranscriptional regulation of these modules. 31 ncRNA regulatory modules were found to be significantly associated with overall survival in COAD patients. 17 out of the 31 modules (in which ncRNAs played essential roles) had improved the predictive ability for COAD patient survival compared to only the mRNAs of those modules, which were enriched in the core cancer hallmark pathways with closer interactions. These suggest that the ncRNAs' regulatory modules not only exhibit close relation to COAD progression but also reflect the dynamic significant crosstalk of genes in the modules to the different malignant extent of COAD.

LncRNA CRNDE and lncRNA SNHG7 are Promising Biomarkers for Prognosis in Synchronous Colorectal Liver Metastasis Following Hepatectomy

Purpose

Synchronous colorectal liver metastasis (SCLM) had limited availability of tools to predict survival and tumor recurrence. LncRNA CRNDE and lncRNA SNHG7 have been proven to be closely related to cancer progression. However, the predictive value of lncRNA CRNDE and lncRNA SNHG7 in cancer prognosis is still unclear. The purpose of this study was to investigate whether lncRNA CRNDE and lncRNA SNHG7 could be used as promising biomarkers for prognosis prediction of SCLM patients who underwent hepatectomy.

Methods

The expression profile of lncRNA CRNDE and lncRNA SNHG7 in serum of SCLM patients was examined by qRT-PCR. The relationship between lncRNA expression and clinicopathological characteristics was analyzed. The Cox proportional-hazards regression model and Kaplan-Meier analysis were performed to analyze the association between lncRNA expression and overall survival (OS) and tumor recurrence of SCLM patients.

Results

Levels of lncRNA CRNDE and lncRNA SNHG7 in patients who underwent recurrence or death were significantly higher than that of patients with recurrence-free or survival (P<0.01). Both lncRNA CRNDE high level and lncRNA SNHG7 high level showed a significant correlation with differentiation of primary tumor, invasion depth of primary focus, lymph node metastases, number of liver metastases, and liver metastasis grade. High levels of lncRNA CRNDE or lncRNA SNHG7 predicted shorter recurrence time, shorter OS time, higher recurrence rate and lower OS rate. Furthermore, lncRNA CRNDE and lncRNA SNHG7 were independent risk factors for high recurrence and poor OS in SCLM underwent hepatectomy.

Conclusion

Taken together, lncRNA CRNDE and lncRNA SNHG7 could be promising biomarkers for prediction of OS and tumor recurrence in SCLM underwent hepatectomy.

LncRNA SNHG7/miR-34a-5p/SYVN1 axis plays a vital role in proliferation, apoptosis and autophagy in osteoarthritis

BACKGROUND

Osteoarthritis (OA) is one of the most common rheumatic diseases of which clinical symptoms includes swelling, synovitis and inflammatory pain, affect patients' daily life. It was reported that non-coding RNAs play vital roles in OA. However, the regulation mechanism of ncRNA in OA pathogenesis has not been fully elucidated.

METHODS

The expression of SNHG7, miR-34a-5p and SYVN1 was detected using qRT-PCR in tissues, serum and cells. The protein expression of SYVN1, PCNA, cleavage-caspase 3, beclin1 and LC3 were measured using western blot. The RNA immunoprecipitation (RIP), RNA pulldown, and luciferase reporter assays were used to verify the relationship between SNHG7, miR-34a-5p and SYVN1. The MTT and flow cytometry assay was performed to detected cell proliferation and cell apoptosis respectively.

RESULTS

In this study, SNHG7 and SYVN1 expression were down-regulated, but miR-34a-5p was up-regulated in OA tissues and IL-1β treated cells compared with normal tissues and chondrocyte. Functional investigation revealed that up-regulated SNHG7 or down-regulated miR-34a-5p could promote cell proliferation and inhibit cell apoptosis and autophagy in OA cells. More than that, RIP, pulldown and luciferase reporter assay was applied to determine that miR-34a-5p was a target miRNA of SNHG7 and SYVN1 was a target mRNA of miR-34-5p. Rescue experiments showed that overexpression of miR-34a reversed high expression of SNHG7-mediated suppression of apoptosis and autophagy as well as promotion of proliferation, while its knockdown inhibited cell apoptosis and autophagy and promoted cell proliferation which could be impaired by silencing SYVN1. In addition, SNHG7 regulated SYVN1 through sponging miR-34a-5p.

CONCLUSION

SNHG7 sponged miR-34a-5p to affect cell proliferation, apoptosis and autophagy through targeting SYVN1 which provides a novel sight into the pathogenesis of OA.

Accumulation of kynurenine elevates oxidative stress and alters microRNA profile in human bone marrow stromal cells

Kynurenine, a metabolite of tryptophan breakdown, has been shown to increase with age, and plays a vital role in a number of age-related pathophysiological changes, including bone loss. Accumulation of kynurenine in bone marrow stromal cells (BMSCs) has been associated with a decrease in cell proliferation and differentiation, though the exact mechanism by which kynurenine mediates these changes is poorly understood. MiRNAs have been shown to regulate BMSC function, and accumulation of kynurenine may alter the miRNA expression profile of BMSCs. The aim of this study was to identify differentially expressed miRNAs in human BMSCs in response to treatment with kynurenine, and correlate miRNAs function in BMSCs biology through bioinformatics analysis. Human BMSCs were cultured and treated with and without kynurenine, and subsequent miRNA isolation was performed. MiRNA array was performed to identify differentially expressed miRNA. Microarray analysis identified 50 up-regulated, and 36 down-regulated miRNAs in kynurenine-treated BMSC cultures. Differentially expressed miRNA included miR-1281, miR-330-3p, let-7f-5p, and miR-493-5p, which are important for BMSC proliferation and differentiation. KEGG analysis found up-regulated miRNA targeting glutathione metabolism, a pathway critical for removing oxidative species. Our data support that the kynurenine dependent degenerative effect is partially due to changes in the miRNA profile of BMSCs.

Long non-coding RNA small nucleolar RNA host gene 7 expression level in prostate cancer tissues predicts the prognosis of patients with prostate cancer

Long non-coding small nucleolar RNA host gene 7 (lncRNA SNHG7) is located on chromosome 9q34.3 in length of 984 bp. SNHG7 has been found to play the role of oncogene in varieties of cancers, and its dysregulation has been found to be associated with carcinogenesis and progression. In the present study, we examined the expression of SNHG7 in prostate cancer tissues and in paired adjacent normal prostate tissues, and we further explored the clinical significance and prognostic value of SNHG7 in prostate cancer patients.A total of 127 prostate cancer tissues were collected from prostate cancer patients who underwent radical prostatectomy between April 2011 and March 2019 at the department of urology, Pudong New Area People's Hospital. Real-time quantitative polymerase chain reaction experiment was performed to detect the relative expressions of SNHG7 in the prostate cancer tissues and normal prostate tissues. The Kaplan-Meier method was used to create survival curves and the log-rank test was used to determine statistical significance. A Cox proportional hazard analysis was used to evaluate the prognostic factors in univariate and multivariate analyses.Compared with paired adjacent normal prostatic tissues, SNHG7 expression was increased in prostate cancer tissues (P < .001). Increased SNHG7 expression correlated with Gleason score (P = .021), bone metastasis (P = .013), pelvic lymph node metastasis (P = .008), and TNM stage (P = .007). Multivariate Cox regression analyses revealed increased SNHG7 expression was independently associated with a poor prognosis of prostate cancer patients (hazard ratio [HR] = 2.839, 95% confidence interval [CI] = 1.921-8.382, P = .038).This study showed that lncRNA-SNHG7 was overexpressed in prostate cancer tissues, and it might contributes to the development and progression of prostate cancer. Furthermore, the SNHG7 expression was associated with the prognosis of prostate cancer, suggesting a potential target for the treatment and prognosis of prostate cancer. Nevertheless, the underlying modulatory mechanism by which SNHG7 aggravates prostate cancer progression need to be further studied.

SNHG7: A novel vital oncogenic lncRNA in human cancers

Long noncoding RNAs (lncRNAs) are a group of RNAs that lack protein-coding ability, with lengths greater than 200 nucleotides. Increasing evidence has indicated that they mediate multiple physiological and pathological processes by regulating gene expression at the epigenetic, transcriptional, post-transcriptional, and translational levels. The deregulation of lncRNAs was demonstrated to have tumor suppressive or oncogenic effects, and thus, these molecules play vital regulatory roles in tumor initiation and progression. Small nucleolar RNA hostgene 7 (SNHG7) is a lncRNA located on chromosome 9q34.3. Different studies have explored the potential role of SNHG7 in the development and progression of multiple human malignancies such as bladder, breast, colorectal, esophageal, gastric, and prostate cancer, as well as osteosarcoma, among others, and high expression predicts poor prognosis and poor survival for such patients. Moreover, this molecule can promote proliferation and metastasis, while inhibiting apoptosis in cancer cells. The present review highlights the latest insights into the expression, functional roles, and molecular mechanisms of SNHG7 in different human malignancies.

Long Noncoding RNA SNHG7, a Molecular Sponge for microRNA-485, Promotes the Aggressive Behavior of Cervical Cancer by Regulating PAK4

Purpose

A long noncoding RNA called small nucleolar RNA host gene 7 (SNHG7) is known to be a key regulator of biological processes in multiple human cancer types. In this study, our aims were to determine the expression status of SNHG7 in cervical cancer, to figure out the detailed roles of SNHG7 in cervical cancer cells, and to identify the mechanism underlying the activity of SNHG7 in cervical cancer.

Methods

Reverse-transcription quantitative PCR was performed to measure SNHG7 expression in cervical cancer. A Cell Counting Kit-8 assay, flow-cytometric analysis, cell migration and invasion assays, and a tumor xenograft experiment were conducted to respectively determine the effects of SNHG7 on cervical cancer cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo.

Results

SNHG7 was found to be markedly upregulated in cervical cancer tissues and cell lines. Higher SNHG7 expression significantly correlated with FIGO stage, lymph node metastasis, the depth of cervical invasion, and shorter overall survival in patients with cervical cancer. Functional experiments indicated that a SNHG7 knockdown attenuated proliferation, migration, and invasiveness and promoted apoptosis of cervical cancer cells in vitro. The SNHG7 knockdown also slowed tumor growth in vivo. Further investigation showed that SNHG7 acts as a competing endogenous RNA for microRNA-485 (miR-485) in cervical cancer cells, and the inhibitory actions of the SNHG7 knockdown on the malignant phenotype were reversed by miR-485 inhibition. P21-activated kinase 4 (PAK4) was identified as a direct target gene of miR-485 in cervical cancer, and PAK4 expression was promoted by SNHG7.

Conclusion

SNHG7 functions as an oncogenic RNA in cervical cancer, competitively binds to miR-485, and thereby upregulates PAK4. This SNHG7–miR-485–PAK4 regulatory network may provide insights into the pathogenesis of cervical cancer, and can help in the identification of novel diagnostic and therapeutic approaches for cervical cancer.

SNHG7 Facilitates Glioblastoma Progression by Functioning as a Molecular Sponge for MicroRNA-449b-5p and Thereby Increasing MYCN Expression

BACKGROUND AND AIMS

Long noncoding RNA (small nucleolar RNA host gene 7) has been reported to be involved in multiple malignancies and acts as an oncogene. However, the potential mechanism of small nucleolar RNA host gene 7 in glioblastoma is rarely known. In this study, we attempted to elucidate the biological effects of small nucleolar RNA host gene 7 and the possible molecular mechanism in glioblastoma.

METHODS

The expression level of small nucleolar RNA host gene 7 in glioblastoma tissues and corresponding tumor cell lines was evaluated by using quantitative real-time polymerase chain reaction. Bioinformatics analyses and dual-luciferase reporter gene assay were conducted to verify the correlation among small nucleolar RNA host gene 7, miR-449b-5p, and MYCN. The role of small nucleolar RNA host gene 7 on cell viability, migration, and invasion was measured.

RESULTS

Small nucleolar RNA host gene 7 expression was markedly increased in glioblastoma tumor tissue. Small nucleolar RNA host gene 7 can sponge miR-449b-5p and negatively regulate miR-449b-5p expression. MiR-449b-5p was remarkably repressed in glioblastoma tissues. Reduction of miR-449b-5p reversed the repressive effects of small nucleolar RNA host gene 7 knockdown on cellular behaviors in glioblastoma. In addition, miR-449b-5p can directly bind with MYCN. Compared with normal samples, MYCN expression was increased. The MYCN expression was negatively related to miR-449b-5p expression while positively related to small nucleolar RNA host gene 7 expression. Rescue experiments revealed that MYCN overexpression reversed the repressive role of small nucleolar RNA host gene 7 knockdown on viability, migration, and invasion of U251 cells.

CONCLUSION

In summary, our results demonstrated that small nucleolar RNA host gene 7 regulates glioblastoma proliferation, migration, and invasion via regulating miR-449b-5p and its target gene MYCN, thereby providing a potential therapeutic target for glioblastoma.

Potential Prognostic and Diagnostic Values of CDC6, CDC45, ORC6 and SNHG7 in Colorectal Cancer

Background

Colorectal cancer (CRC) is a common human malignancy. The aims of this study are to investigate the gene expression profile of CRC and to explore potential strategy for CRC diagnosis, therapy and prognosis.

Methods

We use affy and Limma package of Bioconductor R to do differential expression genes (DEGs) and differential expression lncRNAs (DELs) analysis from the gene datasets (GSE8671, GSE21510, GSE32323, GSE39582 and TCGA) respectively. Then, DEGs were analyzed by GO and KEGG pathway and Kaplan-Meier survival curve and Cox regression analyses were used to find aberrantly expressed genes associated with survival outcome of CRC patients. Real-time PCR assay was used to verify the aberrantly expressed genes expression in CRC samples.

Results

306 up-regulation and 213 down-regulation common DEGs were found. A total of 485 DELs were identified, of which 241 up-regulated and 244 down-regulated. Then, GO and KEGG pathway analyses showed that DEGs were involved in cell cycle, mineral absorption, DNA replication, and Nitrogen metabolism. Among them, Kaplan-Meier survival curve and Cox regression analyses revealed that CDC6, CDC45, ORC6 and SNHG7 levels were significantly associated with survival outcome of CRC patients. Finally, real-time PCR assay was used to verify that the CDC6, CDC45, ORC6 and SNHG7 expression were up-regulated in 198 CRC samples compared with the expression levels in individual-matched adjacent mucosa samples.

Conclusion

CDC6, CDC45, ORC6 and SNHG7 are implicated in CRC initiation and progression and could be explored as potential diagnosis, therapy and prognosis targets for CRC.

SNHG7 accelerates cell migration and invasion through regulating miR-34a-Snail-EMT axis in gastric cancer

Small nucleolar RNA host gene 7 (SNHG7) is a newly recognized oncogenic Long non-coding RNA (lncRNA) in most human cancers. In gastric cancer, SNHG7 has been suggested to enhance cell proliferation and suppressed apoptosis through down-regulating P15 and P16 expression, but the effect of SNHG7 on gastric cancer cell migration and invasion was still unknown. In our study, we aimed to estimate the relationship between SNHG7 expression and clinical and pathological characteristics, and explore the effect of SNHG7 on gastric cancer cell migration and invasion. In our study, the levels of SNHG7 expression in gastric cancer tissues and cell lines were severally higher than in normal adjacent tissues and gastric mucosal epithelial cells. Moreover, high SNHG7 expression was positively correlated with TNM stage, depth of invasion, lymph-node metastasis and distant metastasis in gastric cancer patients. Furthermore, the multivariate Cox proportional hazard analysis further showed high SNHG7 expression was an independent poor prognostic factor for overall survival in gastric cancer patients. The studies in vitro revealed that SNHG7 directly binds to miR-34a and negatively regulates miR-34a expression, and SNHG7 enhances gastric cancer cell migration and invasion through suppressing miR-34a-Snail-EMT axis. In conclusion, SNHG7 functions as oncogenic lncRNA in gastric cancer and may be a potential therapeutic target for gastric cancer patients.Abbreviations: lncRNA: Long non-coding RNA; SNHG7: Small nucleolar RNA host gene 7; EMT: Epithelial mesenchymal transition; TNM: Tumor-Lymph Node-Metastasis.

Drug-induced modifications and modulations of microRNAs and long non-coding RNAs for future therapy against Glioblastoma Multiforme

Non-coding RNAs are known to participate in cancer initiation, progression, and metastasis by regulating the status of chromatin epigenetics and gene expression. Although these non-coding RNAs do not possess defined protein-coding potential, they are involved in the expression and stability of messenger RNA (mRNA). The length of microRNAs (miRs) ranges between 20 and 22 nt, whereas, long non-coding RNAs (lncRNAs) length ranges between 200 nt to 1 Kb. In the case of circular RNAs (circRNAs), the size varies depending upon the length of the exon from where they were derived. Epigenetic regulations of miR and lncRNA genes will influence the gene expression by modulating histone acetylation and methylation patterns. Especially, lncRNAs will act as a scaffold for various epigenetic proteins, such as EZH2 and LSD1, and influence the chromatin epigenetic state at various genomic loci involved at silencing. Thus investigations on the expression of lncRNAs and designing drugs to modulate the expression of these genes will have a profound impact on future therapeutics against cancers such as Glioblastoma Multiforme (GBM) and also against various other diseases. With the recent advancements in genome-wide transcriptomic studies, scientists are focused on the non-coding RNAs and their regulations on various cellular processes involved in GBM and on other types of cancer as well as trying to understand possible epigenetic modulations that help in generating promising therapeutics for the future generations. In this review, the involvement of epigenetic proteins, enzymes that change chromatin architecture and epigenetic landscape and new roles of lncRNAs that are involved in GBM progression are elaborately discussed.

LncRNA SNHG7 accelerates the proliferation, migration and invasion of hepatocellular carcinoma cells via regulating miR-122-5p and RPL4

Long noncoding RNAs (lncRNAs) play vital roles in the development and progression of hepatocellular carcinoma (HCC). The recent study finds a strong correlation between lncRNA small nucleolar RNA host gene 7 (SNHG7) and HCC metastasis. However, the molecular mechanism by which SNHG7 regulates HCC progression has not been investigated. In this study, we found that SNHG7 was highly expressed in HCC tissues compared to non-tumor tissues. Data from public databases consistently indicated the up-regulated expression of SNHG7 in HCC. Furthermore, the levels of SNHG7 were up-regulated in four HCC cell lines (Huh7, Hep3B, HCCLM3, MHCC97 H) compared with LO2 cells. Interestingly, the elevated expression of SNHG7 was closely correlated with advanced tumor stages, high tumor grades, vascular invasion and poor prognosis of HCC. Knockdown of SNHG7 markedly inhibited cell proliferation, migration and invasion in HCCLM3 and MHCC97H cells, and prominently suppressed the growth and metastasis of HCCLM3 cells in vivo. Mechanistically, SNHG7 silencing increased the level of miR-122-5p in HCC cells. Luciferase reporter assay revealed the direct interaction between SNHG7 and miR-122-5p. Moreover, SNHG7 knockdown decreased the levels of ribosomal protein L4 (RPL4) mRNA and protein in HCC cells. Accordingly, the stability of RPL4 mRNA was reduced by SNHG7 silencing. More importantly, either miR-122-5p knockdown or RPL4 restoration partially reversed SNHG7 silencing-induced tumor suppressive effects on HCC cells. In conclusion, we demonstrated that SNHG7 expression was up-regulated in HCC. SNHG7 contributed to HCC progression by regulating miR-122-5p and RPL4. Therefore, SNHG7 might be a potential biomarker and therapeutic target for HCC.

Long non-coding RNA small nucleolar RNA host gene 7 is upregulated and promotes cell proliferation in thyroid cancer

Thyroid cancer (THCA) is one of the most common types of endocrine cancer worldwide. However, the mechanisms underlying THCA progression have not been fully elucidated. Recent studies have demonstrated that long non-coding RNAs (lncRNAs) are dysregulated in human diseases, and are involved in regulating various biological processes. Furthermore, several reports have indicated that lncRNAs serve important roles in THCA. In the present study, a dataset from The Cancer Genome Atlas was used to analyze the expression levels and the clinical information of small nucleolar RNA host gene 7 (SNHG7) in THCA. Starbase was used to construct the competing endogenous RNA network. The Molecule Annotation System was used to analyze the data from Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Furthermore, cell proliferation and cell cycle assays were used to detect the functions of SNHG7 in THCA. The present study revealed for the first time, to the best of our knowledge, that SNHG7 is markedly upregulated in THCA samples following analysis of The Cancer Genome Atlas datasets. SNHG7 expression was higher in advanced stage compared with early stage THCA samples. In addition, high expression levels of SNHG7 were associated with shorter survival times in THCA patients compared with low expression levels. Bioinformatics analysis revealed that SNHG7 was associated with the processes of ‘protein translation’, ‘viral life cycle’, ‘RNA processing’, ‘mRNA splicing’, ‘histone ubiquitination’, ‘endoplasmic reticulum-to-Golgi vesicle-mediated transport’, ‘sister chromatid cohesion’, ‘DNA damage checkpoint regulation’, ‘translation’ and ‘the spliceosome’. Additionally, knockdown of SNHG7 significantly inhibited thyroid cancer cell proliferation and cell cycle progression in vitro. Taken together, the results obtained in the present study suggested that SNHG7 may serve as a novel therapeutic and prognostic target for THCA.