Knockdown of SNHG8 repressed the growth, migration, and invasion of colorectal cancer cells by directly sponging with miR-663

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

Involvement of the oncogenic small nucleolar RNA SNORA24 in regulation of p53 stability in colorectal cancer

Colorectal cancer (CRC) is a common malignant cancer worldwide. Although the molecular mechanism of CRC carcinogenesis has been studied extensively, the details remain unclear. Small nucleolar RNAs (snoRNAs) have recently been reported to have essential functions in carcinogenesis, although their roles in CRC pathogenesis are largely unknown. In this study, we found that the H/ACA snoRNA SNORA24 was upregulated in various cancers, including CRC. SNORA24 expression was significantly associated with age and history of colon polyps in CRC patient cohorts, with high expression associated with a decreased 5-year overall survival. Our results indicated that the oncogenic function of SNORA24 is mediated by promoting G1/S phase transformation, cell proliferation, colony formation, and growth of xenograft tumors. Furthermore, SNORA24 knockdown induced massive apoptosis. RNA-sequencing and gene ontology (GO) enrichment analyses were performed to explore its downstream targets. Finally, we confirmed that SNORA24 regulates p53 protein stability in a proteasomal degradation pathway. Our study clarifies the oncogenic role of SNORA24 in CRC and advance the current model of the role of the p53 pathway in this process.

Connection of Cancer Exosomal LncRNAs, Sponging miRNAs, and Exosomal Processing and Their Potential Modulation by Natural Products

Cancerous exosomes contain diverse biomolecules that regulate cancer progression. Modulating exosome biogenesis with clinical drugs has become an effective strategy for cancer therapy. Suppressing exosomal processing (assembly and secretion) may block exosomal function to reduce the proliferation of cancer cells. However, the information on natural products that modulate cancer exosomes lacks systemic organization, particularly for exosomal long noncoding RNAs (lncRNAs). There is a gap in the connection between exosomal lncRNAs and exosomal processing. This review introduces the database (LncTarD) to explore the potential of exosomal lncRNAs and their sponging miRNAs. The names of sponging miRNAs were transferred to the database (miRDB) for the target prediction of exosomal processing genes. Moreover, the impacts of lncRNAs, sponging miRNAs, and exosomal processing on the tumor microenvironment (TME) and natural-product-modulating anticancer effects were then retrieved and organized. This review sheds light on the functions of exosomal lncRNAs, sponging miRNAs, and exosomal processing in anticancer processes. It also provides future directions for the application of natural products when regulating cancerous exosomal lncRNAs.

A review on the role of SNHG8 in human disorders

Small nucleolar RNA host gene 8 (SNHG8) is a long non-coding RNA that has physiological roles in epithelial and muscle satellite cells. This lncRNA has been reported to be over-expressed in a variety of cancer cell lines. Its silencing has attenuated tumor growth in animal models of cancers. SNHG8 can be served as a molecular sponge for some miRNAs to regulate their target genes. miR-634/ZBTB20, miR-335-5p/PYGO2, miR588/ATG7, miR-152/c-MET, miR-1270/BACH1, miR-491/PDGFRA, miR-512-5p/TRIM28, miR-149-5p/PPM1F, miR-542-3p/CCND1/CDK6, miR-656-3p/SERBP1, miR-656-3p/SATB1, miR-1270/S100A11 and miR-384/HOXB7 are examples of molecular axes being regulated by SNHG8 in the context of cancer. Moreover, it can affect pathogenesis of atherosclerosis, chronic cerebral ischemia, acute gouty arthritis, ischemic stroke and myocardial infarction through modulation of a number of molecular axes such as SNHG8/miR-384/Hoxa13/FAM3A and miR-335/RASA1 as well as NF-κB signaling pathway. The current review aims at summarization of the role of SNHG8 in diverse human disorders.

Suppression of small nucleolar RNA host gene 8 (SNHG8) inhibits the progression of colorectal cancer cells

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies around the world with high mortality. Accumulating evidences demonstrate that long non-coding RNAs (lncRNAs) play critical roles in CRC tumorigenesis by regulating different pathways of carcinogenesis. SNHG8 (small nucleolar RNA host gene 8), a lncRNA, is highly expressed in several cancers and acts as an oncogene that promotes cancer progression. However, the oncogenic role of SNHG8 in CRC carcinogenesis and the underlying molecular mechanisms remain unknown. In this study, we explored the role of SNHG8 in CRC cell lines by performing a series of functional experiments. Similar to the data reported in the Encyclopedia of RNA Interactome, our RT-qPCR results showed that SNHG8 expression was significantly upregulated in CRC cell lines (DLD-1, HT-29, HCT-116, and SW480) compared to the normal colon cell line (CCD-112CoN). We performed dicer-substrate siRNA transfection to knockdown the expression of SNHG8 in HCT-116 and SW480 cell lines which were expressing high levels of SNHG8. SNHG8 knockdown significantly reduced CRC cell growth and proliferation by inducing autophagy and apoptosis pathways through the AKT/AMPK/mTOR axis. We performed wound healing migration assay and demonstrated that SNHG8 knockdown significantly increased migration index in both cell lines, indicating reduced migration abilities of cells. Further investigation showed that SNHG8 knockdown suppresses epithelial to mesenchymal transition and reduces cellular migratory properties of CRC cells. Taken together, our study suggests that SNHG8 acts as an oncogene in CRC through the mTOR-dependent autophagy, apoptosis, and EMT pathways. Our study provides a better understanding the role of SNHG8 in CRC at molecular level and SNHG8 might be used as novel therapeutic target for CRC management.

Epigenetic regulation of autophagy by non-coding RNAs in gastrointestinal tumors: Biological functions and therapeutic perspectives

Cancer is the manifestation of changes and mutations in genetic and epigenetic levels. Non-coding RNAs (ncRNAs) are commonly dysregulated in disease pathogenesis, and their role in cancer has been well-documented. The ncRNAs regulate various molecular pathways and mechanisms in cancer that can lead to induction/inhibition of carcinogenesis. Autophagy is a molecular "self-digestion" mechanism its function can be pro-survival or pro-death in tumor cells. The aim of the present review is to evaluate the role of ncRNAs in regulating autophagy in gastrointestinal tumors. The role of the ncRNA/autophagy axis in affecting the progression of gastric, liver, colorectal, pancreatic, esophageal, and gallbladder cancers is investigated. Both ncRNAs and autophagy mechanisms can function as oncogenic or onco-suppressor and this interaction can determine the growth, invasion, and therapy response of gastrointestinal tumors. ncRNA/autophagy axis can reduce/increase the proliferation of gastrointestinal tumors via the glycolysis mechanism. Furthermore, related molecular pathways of metastasis, such as EMT and MMPs, are affected by the ncRNA/autophagy axis. The response of gastrointestinal tumors to chemotherapy and radiotherapy can be suppressed by pro-survival autophagy, and ncRNAs are essential regulators of this mechanism. miRNAs can regulate related genes and proteins of autophagy, such as ATGs and Beclin-1. Furthermore, lncRNAs and circRNAs down-regulate miRNA expression via sponging to modulate the autophagy mechanism. Moreover, anti-cancer agents can affect the expression level of ncRNAs regulating autophagy in gastrointestinal tumors. Therefore, translating these findings into clinics can improve the prognosis of patients.

Association between small nucleolar RNA host gene expression and survival outcome of colorectal cancer patients: A meta-analysis based on PRISMA and bioinformatics analysis

Introduction

Growing evidence shows that long non-coding RNA small nucleolar RNA host genes (lncRNA SNHGs) enact an pivotal regulatory roles in the shorter survival outcome of colorectal cancer (CRC). However, no research has systematically evaluated the correlation among lncRNA SNHGs expression and survival outcome of CRC. This research indented to screen whether exist potential prognostic effect of lncRNA SNHGs in CRC patientss using comprehensive review and meta-analysis.

Methods

Systematic searches were performed from the six relevant databases from inception to October 20, 2022. The quality of published papers was evaluated in details. We pooled the hazard ratios (HR) with 95% confidence interval (CI) through direct or indirect collection of effect sizes, and odds ratios (OR) with 95% CI by collecting effect sizes within articles. Detailed downstream signaling pathways of lncRNA SNHGs were summarized in detail.

Results

25 eligible publications including 2,342 patients were finally included to appraise the association of lncRNA SNHGs with prognosis of CRC. Elevated lncRNA SNHGs expression was revealed in colorectal tumor tissues. High lncSNHG expression means bad survival prognosis in CRC patients (HR=1.635, 95% CI: 1.405-1.864, P<0.001). Additionally, high lncRNA SNHGs expression was inclined to later TNM stage (OR=1.635, 95% CI: 1.405-1.864, P<0.001), distant lymph node invasion, distant organ metastasis, larger tumor diameter and poor pathological grade. Begg's funnel plot test using the Stata 12.0 software suggested that no significant heterogeneity was found.

Conclusion

Elevated lncRNA SNHGs expression was revealed to be positively correlated to discontented CRC clinical outcome and lncRNA SNHG may act as a potential clinical prognostic index for CRC patients.

miRNA-633 and KAI1 as Potential Biomarkers of Malignant Melanoma with Gastric Cancer

OBJECTIVE

Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer.

METHODS

Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019. The clinical parameters included clinical information, such as sex, age, tumor size, and tumor staging. RT-qPCR was used to detect the expression of KAI1 and miRNA- 633. The role of KAI1 and miRNA-633 on the overall survival of melanoma was explored by the Pearson chi-square test, Spearman-rho correlation test, Univariate and multivariate cox regression analyses, and Kaplan-Meier method. Furthermore, the bioinformatic analysis was used to verify the role of KAI1 and miRNA-633 on malignant melanoma with gastric cancer.

RESULTS

The expression of KAI1 and miRNA-633 was significantly related with the tumor size and staging of tumor (p<0.05) based on the Pearson chi-square test. Spearman's correlation coefficient displayed that KAI1 was significantly correlated with the miRNA-633 (ρ=-0.439, p=0.001). The result of multivariate cox proportional regression analysis showed that KAI1 (HR =0.109, 95% CI: 0.031-0.375, p< 0.001), and miRNA-633 (HR = 13.315, 95% CI: 3.844-46.119, p<0.001) were significantly associated with overall survival.

CONCLUSION

The low expression level of KAI1 and high expression of miRNA-633 are significantly correlated with the poor overall survival prognosis of malignant melanoma with gastric cancer, to provide a basis for KAI1 and miRNA-633 to become novel molecular targets for malignant melanoma with gastric cancer.

Long noncoding RNA SNHG8 promotes chemoresistance in gastric cancer via binding with hnRNPA1 and stabilizing TROY expression

AIMS

To determine SNHG8's function and potential mechanisms in gastric cancer (GC) chemoresistance.

METHODS

We assessed SNHG8 expression in GC cell lines, GC/CDDP cell lines (cell lines treated with cisplatin), and 42 GC tissues and SNHG8 levels in the lncRNA microarray analysis of AGS/CDDP and AGS cell lines. We also examined GC cell viability in vivo and in vitro and its apoptosis level with Flow cytometry assays. SNHG8 was localized in subcells using fluorescence in situ hybridization (FISH) and cell fraction assays, hnRNPA1's link to SNHG8 was determined utilizing RNA immunoprecipitation (RIP) and FISH assays, gene expression profiles were assessed employing RNA transcriptome sequencing, and hnRNPA1's relationship with TROY was ascertained with the RIP assay.

RESULTS

SNHG8 increased significantly in GC cell lines and GC tissues. However, a decrease in its expression promoted sensitivity to chemotherapy and inhibited DNA damage repair in vitro and in vivo. SNHG8 appeared to regulate TROY expression via linking with hnRNPA1. Reducing TROY levels considerably stimulated GC cell chemosensitivity, whereas heightening them partially rescued the rate of chemoresistance caused by downregulating SNHG8.

CONCLUSION

In summary, the "SNHG8/hnRNPA1-TROY" axis is crucial to GC chemoresistance.

Construction of immune-related LncRNAs classifier to predict prognosis and immunotherapy response in thymic epithelial tumors

The primary objective of this study was to construct an immune-related long non-coding RNAs (IRLs) classifier to precisely predict the prognosis and immunotherapy response of patients with thymic epithelial tumors (TET).Based on univariable Cox regression analysis and Lasso regression, six prognosis-related IRLs (AC004466.3,AC138207.2, AC148477.2, AL450270.1, HOXB-AS1 and SNHG8) were selected to build an IRL classifier. Importantly, results of qRT-PCR validated that higher expression levels of AC138207.2, AC148477.2, AL450270.1 and SNHG8 as well as lower expression levels of AC004466.3, and HOXB-AS1 in TETs samples compared to normal controls. The IRL classifier could effectively classify patients into the low-risk and high-risk groups based on the different survival parameters. In terms of predictive ability and clinical utility, the IRL classifier was superior to Masaoka staging system. Additionally, IRL classifier is significantly associated with immune cells infiltration (dendritic cells, activated CD4 memory T cells and tumor-infiltrating lymphocyte (TIL), T cell subsets in particular), immune microenvironment (immune score and immune checkpoint inhibitors), and immunogenicity (TMB) in TETs, which hints that IRL classifier is tightly correlated with immune characteristics and might guide more effective immunotherapy strategies for TETs patients. Encouragingly, according to TIDE algorithm, there were more immunotherapy responders in the low-risk IRL subgroup and the IRL score was robustly negatively linked to the immunotherapeutic response. To sum up, the IRL classifier was established, which can be used to predict the prognosis, immune infiltration status, immunotherapy response in TETs patients, and may facilitate personalized counseling for immunotherapy.

LncRNA-miRNA-mRNA regulatory axes in endometrial cancer: a comprehensive overview

INTRODUCTION

Recent research on tumorigenesis and progression has opened up an array of novel molecular mechanisms in the form of interactions between cellular non-coding RNAs (long non-coding RNA[lncRNA]/microRNA [miRNA]) and coding transcripts that regulate health and disease. Endometrial cancer (EC) is a prominent gynecological malignancy with a high incidence rate and poorly known etiology and prognostic factors that hinder the success of disease management. The emerging role of lncRNA-miRNA-mRNA interactions and their dysregulation in the pathophysiology of EC has been elucidated in many recent studies.

METHODS

A thorough literature review was conducted to explore information about lncRNA-miRNA-mRNA axes in EC.

RESULTS

Several lncRNAs act as molecular sponges that sequester various tumor suppressor miRNAs to inhibit their function, leading to the dysregulation of their target mRNA transcripts that contribute to the EC regulation.

CONCLUSIONS

This review summarizes these networks of molecular mechanisms and their contribution to different aspects of endometrial carcinogenesis, leading to a better conceptualization of the molecular pathways that underlie the disease and helping establish novel diagnostic biomarkers and therapeutic intervention points to aid the curative intent of EC.

METTL14 gene polymorphisms decrease Wilms tumor susceptibility in Chinese children

BACKGROUND

Wilms tumor is a highly heritable malignancy. Aberrant METTL14, a critical component of N6-methyladenosine (m⁶A) methyltransferase, is involved in carcinogenesis. The association between genetic variants in the METTL14 gene and Wilms tumor susceptibility remains to be fully elucidated. We aimed to assess whether variants within this gene are implicated in Wilms tumor susceptibility.

METHODS

A total of 403 patients and 1198 controls were analyzed. METTL14 genotypes were assessed by TaqMan genotyping assay.

RESULT

Among the five SNPs analyzed, rs1064034 T > A and rs298982 G > A exhibited a significant association with decreased susceptibility to Wilms tumor. Moreover, the joint analysis revealed that the combination of five protective genotypes exerted significantly more protective effects against Wilms tumor than 0-4 protective genotypes with an OR of 0.69. The stratified analysis further identified the protective effect of rs1064034 T > A, rs298982 G > A, and combined five protective genotypes in specific subgroups. The above significant associations were further validated by haplotype analysis and false-positive report probability analysis. Preliminary mechanism exploration indicated that rs1064034 T > A and rs298982 G > A are correlated with the expression and splicing event of their surrounding genes.

CONCLUSIONS

Collectively, our results suggest that METTL14 gene SNPs may be genetic modifiers for the development of Wilms tumor.

SNHG8 Promotes the Progression of Epstein-Barr Virus-Associated Gastric Cancer via Sponging miR-512-5p and Targeting TRIM28

SNHG8, a family member of small nucleolar RNA host genes (SNHG), has been reported to act as an oncogene in gastric carcinoma (GC). However, its biological function in Epstein–Barr virus (EBV)-associated gastric cancer (EBVaGC) remains unclear. This study investigated the role of SNHG8 in EBVaGC. Sixty-one cases of EBVaGC, 20 cases of non-EBV-infected gastric cancer (EBVnGC), and relative cell lines were studied for the expression of SNHG8 and BHRF1 (BCL2 homolog reading frame 1) encoded by EBV with Western blot and qRT-PCR assays. The relationship between the expression levels of SNHG8 and the clinical outcome in 61 EBVaGC cases was analyzed. Effects of overexpression or knockdown of BHRF1, SNHG8, or TRIM28 on cell proliferation, migration, invasion, and cell cycle and the related molecules were determined by several assays, including cell proliferation, colony assay, wound healing assay, transwell invasion assay, cell circle with flow cytometry, qRT-PCR, and Western blot for expression levels. The interactions among SNHG8, miR-512-5p, and TRIM28 were determined with Luciferase reporter assay, RNA immunoprecipitation (RIP), pull-down assays, and Western blot assay. The in vivo activity of SNHG8 was assessed with SNHG8 knockdown tumor xenografts in zebrafish. Results demonstrated that the following. (1) BHRF1 and SNHG8 were overexpressed in EBV-encoded RNA 1-positive EBVaGC tissues and cell lines. BHRF1 upregulated the expressions of SNHG8 and TRIM28 in AGS. (2) SNHG8 overexpression had a significant correlation with tumor size and vascular tumor thrombus. Patients with high SNHG8 expression had poorer overall survival (OS) compared to those with low SNHG8 expression. (3) SNHG8 overexpression promoted EBVaGC cell proliferation, migration, and invasion in vitro and in vivo, cell cycle arrested at the G2/M phase via the activation of BCL-2, CCND1, PCNA, PARP1, CDH1, CDH2 VIM, and Snail. (4) Results of dual-luciferase reporter assay, RNA immunoprecipitation, and pull-down assays indicated that SNHG8 sponged miR-512-5p, which targeted on TRIM28 and promoted cancer malignant behaviors of EBVaGC cells. Our data suggest that BHRF1 triggered the expression of SNHG8, which sponged miR-512-5p and upregulated TRIM28 and a set of effectors (such as BCL-2, CCND1, CDH1, CDH2 Snail, and VIM) to promote EBVaGC tumorigenesis and invasion. SNHG8 could be an independent prognostic factor for EBVaGC and sever as target for EBVaGC therapy.

Construction and Integrated Analysis of Competitive Endogenous Long Non-Coding RNA Network in Thoracic Aortic Dissection

Background

Long non-coding RNAs (lncRNAs) can act as a competitive endogenous RNA (ceRNA) to regulate gene expression by sequestering the microRNA (miRNA). However, the lncRNA-miRNA-mRNA ceRNA network in thoracic aortic dissection (TAD) has been rarely documented.

Methods

Three Gene Expression Omnibus (GEO) datasets were used to detect differentially expressed mRNAs, miRNAs, and lncRNAs in TAD. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for the differentially expressed mRNAs. A protein–protein interaction network for differentially expressed mRNAs was also constructed, and hub genes were identified. We established a ceRNA network of TAD based on the differentially expressed miRNAs, mRNAs and lncRNAs, and verified our results using an independent dataset and quantitative real-time PCR (qRT-PCR).

Results

In TAD, 267 lncRNAs, 81 miRNAs, and 346 mRNAs were identified as differentially expressed. The established ceRNA network consisted of seven lncRNA nodes, three mRNA nodes, and three miRNA nodes, and the expression of miRNAs in TAD was opposite to that of lncRNAs and mRNAs. Subsequently, an independent GEO dataset and qRT-PCR were used to validate the expression of three mRNAs. In addition, the expression differences in SLC7A5, associated miRNA and lncRNA were verified. According to gene set enrichment analysis of SLC7A5, the most significant KEGG pathway was considerably enriched in spliceosome and pentose phosphate pathway.

Conclusion

We established a novel ceRNA regulatory network in TAD, which provides valuable information for further research in the molecular mechanisms of TAD.

Long non-coding RNA SNHG8 enhances triple-negative breast cancer cell proliferation and migration by regulating the miR-335-5p/PYGO2 axis

Background

Growing evidence has demonstrated that long non-coding RNAs (lncRNAs) can function as modulators in the development of triple-negative breast cancer (TNBC). However, the function of lncRNA small nucleolar RNA host gene 8 (SNHG8) in TNBC remains unclear. Therefore, our study aimed at investigating the role of SNHG8 in the proliferation and migration of TNBC cells.

Methods

SNHG8 expression was evaluated using RT-qPCR assay. Cell proliferation and migration were assessed by EdU, colony formation and Transwell assays. The levels of proteins related to EMT process were examined by western blot assay. The interaction among SNHG8, miR-335-5p and pygopus family PHD finger 2 (PYGO2) was detected by RIP assay, RNA pull down assay and luciferase reporter assay.

Results

SNHG8 expression was significantly up-regulated in TNBC cells. SNHG8 silencing obviously inhibited TNBC cell proliferation, migration and EMT process. Moreover, SNHG8 acted as a sponge to sequester miR-335-5p in TNBC cells. Besides, PYGO2 was proven as a target gene of miR-335-5p, and SNHG8 promoted TNBC cell proliferation, migration and EMT process through regulating miR-335-5p and PYGO2.

Conclusions

Totally, our study indicated that SNHG8 promoted TNBC cell proliferation and migration by regulating the miR-335-5p/PYGO2 axis.

Expression-based prediction of human essential genes and candidate lncRNAs in cancer cells

MOTIVATION

Essential genes are required for the reproductive success at either cellular or organismal level. The identification of essential genes is important for understanding the core biological processes and identifying effective therapeutic drug targets. However, experimental identification of essential genes is costly, time consuming and labor intensive. Although several machine learning models have been developed to predict essential genes, these models are not readily applicable to lncRNAs. Moreover, the currently available models cannot be used to predict essential genes in a specific cancer type.

RESULTS

In this study, we have developed a new machine learning approach, XGEP (eXpression-based Gene Essentiality Prediction), to predict essential genes and candidate lncRNAs in cancer cells. The novelty of XGEP lies in the utilization of relevant features derived from the TCGA transcriptome dataset through collaborative embedding. When evaluated on the pan-cancer dataset, XGEP was able to accurately predict human essential genes and achieve significantly higher performance than previous models. Notably, several candidate lncRNAs selected by XGEP are reported to promote cell proliferation and inhibit cell apoptosis. Moreover, XGEP also demonstrated superior performance on cancer-type-specific datasets to identify essential genes. The comprehensive lists of candidate essential genes in specific cancer types may be used to guide experimental characterization and facilitate the discovery of drug targets for cancer therapy.

AVAILABILITY AND IMPLEMENTATION

The source code and datasets used in this study are freely available at https://github.com/BioDataLearning/XGEP.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Small nucleolar RNA host gene 8: A rising star in the targets for cancer therapy

Long non-coding RNAs (lncRNAs) are a group of transcripts that have been considered essential participants in cancer pathogenesis and progression over the past few decades. Small nucleolar RNA host gene 8 (SNHG8) is a newly discovered lncRNA that belongs to the SNHG family, a group of transcripts that can be processed into small nucleolar RNAs and exert important biological functions. As an oncogenic factor, SNHG8 is upregulated in multiple cancer types. Herein, we summarize the biological role of SNHG8 in different cancer types and the underlying mechanisms related to the interaction between SNHG8 and microRNAs, mRNAs, and proteins. In addition, this study emphasizes the clinical value of SNHG8 in cancer, hoping to provide new insights into cancer diagnosis, prognosis, and treatment.

Loss of lncRNA SNHG8 promotes epithelial-mesenchymal transition by destabilizing CDH1 mRNA

Long non-coding RNAs (lncRNAs) are widely involved in a variety of biological processes, including epithelial-mesenchymal transition (EMT). In the current study, we found that lncRNA small nucleolar RNA host gene 8 (SNHG8) was tightly correlated with EMT-associated gene signatures, and was down-regulated by Zinc finger E-box-binding homeobox 1 (ZEB1) during EMT progress. Functionally, knockdown of SNHG8 induced EMT in epithelial cells, through destabilizing the CDH1 mRNA dependent on a 17-nucleotide sequence shared by SNHG8 and CDH1. In addition, analysis with public database showed that SNHG8 tended to be down-regulated in different cancer types and the lower expression of SNHG8 predicted poorer prognosis. Taken together, our study reports a ZEB1-repressed lncRNA SNHG8 which is important for stabilizing CDH1 mRNA, thereby maintaining the epithelial status of epithelial cells.

Long non-coding RNA SNHG8 promotes prostate cancer progression through repressing miR-384 and up-regulating HOXB7

BACKGROUND

Multiple long non-coding RNAs (lncRNAs) have been demonstrated to function as vital regulators in the progression of prostate cancer (PCa). In the present study, we aimed to probe the function of lncRNA small nucleolar RNA host gene 8 (SNHG8) in PCa progression.

METHODS

A quantitative real-time polymerase chain reaction and western blotting were utilized to measure SNHG8, microRNA-384 (miR-384) and homeobox B7 (HOXB7) expression. Call-couting kit-8 and bromodeoxyuridine experiments were employed to evaluate PCa cell proliferation. Transwell experiments were performed to detect PCa cell migration and invasion. Dual-luciferase reporter experiments and RNA immunoprecipitation experiments were conducted to determine the targeting relationships among miR-384, SNHG8 and HOXB7.

RESULTS

SNHG8 was up-regulated in PCa tissues and cells. Silencing of SNHG8 suppressed the proliferation, migration and invasion of PCa cells. SNHG8 functioned as a molecular sponge to repress miR-384. The effects of SNHG8 knockdown on PCa cell proliferation, migration and invasion were counteracted by miR-384 inhibition. HOXB7 was confirmed to be a target gene of miR-384. SNHG8 knockdown repressed HOXB7 expression via targeting miR-384.

CONCLUSIONS

SNHG8 promotes PCa cell proliferation, migration and invasion via decoying miR-384 and up-regulating HOXB7.

MicroRNA-663 Regulates Melanoma Progression by Inhibiting FHL3

microRNA-663a (miR-663a) was reported to be highly expressed in cancers. However, its roles in melanoma progression remain unclear. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to measure miR-663a expression level in melanoma cell lines and normal cells. Cell counting kit-8 assay, wound-healing assay, and transwell invasion assay were conducted to analyze biological roles of miR-663a in melanoma. Luciferase activity reporter assay was conducted to validate the connection of miR-663a and Four and a half LIM domain (FHL) protein 3 (FHL3) in melanoma. Our results showed miR-663a expression level was significantly increased in melanoma cells compared with normal cells. Silencing miR-663a expression suppresses melanoma cell proliferation, migration, and invasion in vitro. Moreover, FHL3 was validated as a functional target of miR-663a. Knockdown of FHL3 partially rescued the inhibitory effects of miR-663a inhibitor on melanoma cell behaviors. Together, our work provided evidence that miR-663a functions as an oncogenic miRNA in melanoma.

lncRNA SNHG8 promotes aggressive behaviors of nasopharyngeal carcinoma via regulating miR-656-3p/SATB1 axis

BACKGROUND

Long non-coding RNA (lncRNA) has been proposed to regulate tumorigenesis, however, the role of small nucleolar RNA host gene 8 (SNHG8) in nasopharyngeal carcinoma (NPC) remains unclear.

METHODS

Levels of SNHG8 in NPC tissues and cells were analyzed with real-time quantitative PCR method. Cell counting kit-8 assay, colony formation assay, wound-healing assay, and transwell invasion assay were performed to detect cell viability, migration, and invasion. Luciferase activity assay and RIP assay were performed to explore relationships among SNHG8, microRNA-656-3p (miR-656-3p), and special AT-rich sequence-binding protein 1 (SATB1).

RESULTS

We found SNHG8 level was increased expression in NPC tissues and cells.In vitro assays revealed that SNHG8 stimulates NPC cell proliferation, colony formation, cell migration, and cell invasion. In vivo assay confirmed knockdown of SNHG8 could hamper tumor growth. Furthermore, we showed SNHG8 serves as a sponge for miR-656-3p to regulate SATB1 expression, and participated in NPC progression.

CONCLUSIONS

In summary, our work indicated the importance of SNHG8 in NPC progression, which provided novel treatment methods for NPC.

METTL14 Gene Polymorphisms Confer Neuroblastoma Susceptibility: An Eight-Center Case-Control Study

Neuroblastoma is the primary cause of cancer death in childhood. METTL14 is tightly linked to cancer. However, whether single-nucleotide polymorphisms (SNPs) in the METTL14 gene could predispose to neuroblastoma susceptibility lacks evidence. With an epidemiology case-control study, associations between METTL14 gene SNPs and overall risk for neuroblastoma were estimated in 898 cases and 1,734 controls. Following that, stratified analysis was performed. Among the five analyzed SNPs, rs298982 G>A and rs62328061 A>G exhibited a significant association with decreased susceptibility to neuroblastoma, whereas the associations with increased neuroblastoma susceptibility were observed for rs9884978 G>A and rs4834698 T>C. Moreover, subjects carrying two to five risk genotypes were more inclined to develop neuroblastoma than those with zero to one risk genotypes. The stratified analysis further demonstrated the protective effect of rs298982 G>A and rs62328061 A>G, as well as the predisposing effect of rs4834698 T>C and two to five risk genotypes, in certain subgroups. Haplotype analysis was performed. Moreover, false-positive report probability analysis validated the reliability of the significant results. The expression quantitative trait locus analysis revealed that rs298982 is correlated with the expression levels of its surrounding genes. Our results suggest that some SNPs in the METTL14 gene are associated with predisposition to neuroblastoma.

Long Non-Coding RNA SNHG8 Plays a Key Role in Myocardial Infarction Through Affecting Hypoxia-Induced Cardiomyocyte Injury

Background

The objective of the study was to explore the role of long non-coding RNA SNHG8 (lncRNA SNHG8) in myocardial infarction (MI) and the related mechanism of action.

Material/Methods

In vitro model of MI was established by hypoxia induction in cardiomyocyte line H9c2 cells. H9c2 cells were transfected with control-plasmid, SNHG8-plasmid, control-shRNA and SNHG8-shRNA. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed to measure transfection efficiency. Creatine kinase-muscle/brain (CK-MB) release, cardiac troponin 1 (cTnI) release and mitochondria viability were detected by using related detection kits. MTT (3-(45)-dimethylthiahiazo (-z-y 1)-35-diphenytetrazoliumromide) assay was used to detect cell viability and flow cytometry analysis was used to detect cell apoptosis. Western blot assay was performed to measure protein expression of cleaved-Caspase3, p-p65 and p65. Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR assay were performed to detect expression of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6.

Results

LncRNA SNHG8 was overexpressed in hypoxia-induced cardiomyocytes. SNHG8-plasmid increased lncRNA SNHG8 expression, CK-MB release, cTnI release, and mitochondria viability in hypoxia-induced H9c2 cells. In addition, SNHG8-plasmid reduced cell viability, induced cell apoptosis, and increased expression of cleaved-caspase3, IL-1β, TNF-α, IL-6, and p-p65 in hypoxia-induced H9c2 cells, while the effects of SNHG8-shRNA were opposite.

Conclusions

We demonstrated that lncRNA SNHG8 affected myocardial infarction by affecting hypoxia-induced cardiomyocyte injury via regulation of the NF-κB pathway.

Identification of New Potential LncRNA Biomarkers in Hirschsprung Disease

Hirschsprung disease (HSCR) is a neurocristopathy defined by intestinal aganglionosis due to alterations during the development of the Enteric Nervous System (ENS). A wide spectrum of molecules involved in different signaling pathways and mechanisms have been described in HSCR onset. Among them, epigenetic mechanisms are gaining increasing relevance. In an effort to better understand the epigenetic basis of HSCR, we have performed an analysis for the identification of long non-coding RNAs (lncRNAs) by qRT-PCR in enteric precursor cells (EPCs) from controls and HSCR patients. We aimed to test the presence of a set lncRNAs among 84 lncRNAs in human EPCs, which were previously related with crucial cellular processes for ENS development, as well as to identify the possible differences between HSCR patients and controls. As a result, we have determined a set of lncRNAs with positive expression in human EPCs that were screened for mutations using the exome data from our cohort of HSCR patients to identify possible variants related to this pathology. Interestingly, we identified three lncRNAs with different levels of their transcripts (SOCS2-AS, MEG3 and NEAT1) between HSCR patients and controls. We propose such lncRNAs as possible regulatory elements implicated in the onset of HSCR as well as potential biomarkers of this pathology.

SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway

Background

Glioblastoma has been seen as the most common malignancy of brain tumor. Emerging reports has claimed that SNHG29 (LRRC75A-AS1) was involved in several biological processes via modulation of signaling pathway, and served as an malignant facilitatorin osteosarcoma. However, the specific role of SNHG29 in glioblastoma remains unknown.

Methods

RT-qPCR and microarray were operated to measure genes expression. Western blot was performed to examine protein expression. CCK-8 and colony formation assays were used to evaluate cell proliferation. Cell migration was tested by transwell assay. Nuclear-cytoplasmic fractionation was conducted to locate SNHG29. The binding capacity of miR-223-3p to SNHG29 or CTNND1 3′UTR was verified by RIP and luciferase reporter assay.

Results

SNHG29 presented high expression in glioblastoma to boost cell proliferation, migration and EMT process. In addition, miR-223-3p was validated to bind with SNHG29 after prediction and screening. Furthermore, miR-223-3p was proved to be a negative regulator for its target CTNND1. Then, the inhibition on cell proliferation, migration and EMT process resulted from SNHG29 knockdown was recovered by CTNND1 overexpression. At last, the inhibitive impacts on cell proliferation, migration and EMT process of CTNND1 deficiency was abrogated by LiCl.

Conclusions

In conclusion, SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway, offering a potential therapeutic point for glioblastoma patients.

Syndecan-2 in colorectal cancer plays oncogenic role via epithelial-mesenchymal transition and MAPK pathway

PURPOSE

In this study, we aimed to elucidate the biological roles of Syndecan-2 (SDC2) in colorectal cancer (CRC), thereby further understanding its clinical role.

METHODS

The expression of SDC2 was assessed by qRT-PCR and Western blot analysis. To understand the potential biological role of SDC2, we also explored the correlation between its expression level and clinicopathologic parameters. By using MTT, plate colony formation assay, Transwell invasion assays, and flow cytometry in vitro, the biological impact of SDC2 on CRC cell proliferation, migration, invasion, and apoptosis. In addition, the related signaling pathways were investigated.

RESULTS

SDC2 expression was significantly upregulated in CRC tissues. The expression of SDC2 was highly associated with four parameters, i.e., stage (P < 0.01), vascular invasion (P = 0.0045), lymph node metastasis (P=0.0018), and distant metastasis (P = 0.0019). Knockdown of SDC2 significantly reduced proliferation, migration, and invasion of HCT116 and SW480 cells, and induced cell apoptosis. Moreover, SDC2 promoted epithelial-mesenchymal transition (EMT) in CRC cells, whereas the ratio of p-MEK/MEK and p-ERK/ERK markedly reduced after depleting SDC2.

CONCLUSION

During CRC development, overexpression of SDC2 plays a carcinogenic role in CRC. Therapeutic solutions targeting SDC2 may provide potential insights into CRC prevention and treatment.