SNHG7: A novel vital oncogenic lncRNA in human cancers

lncRNA SNHG4 inhibits ferroptosis by orchestrating miR-150-5p/c-Myb axis in colorectal cancer

LncRNAs have shown to regulate ferroptosis in colorectal cancer (CRC), but the mechanism remains largely unknown. This study unveiled the mechanism of SNHG4 underlying ferroptosis in CRC. RNA-seq and RT-PCR assay confirmed SNHG4 was decreased after Erastin treatment in CRC cells. Overexpression of SNHG4 inhibited and silence promoted CRC cells ferroptosis. SNHG4 was positively correlated to c-Myb in CRC tissues and both located in cytoplasm of CRC cells. RIP and RNA pull-down assays verified the interaction between SNHG4 and c-Myb. Silence of c-Myb alleviated the suppressing effect on ferroptosis by SNHG4 in CRC cells. Dual-luciferase reporter assay revealed that SNHG4 sponging miR-150-5p in CRC cells. Overexpression of SNHG4 decreased the miR-150-5p and increased c-Myb expression. c-Myb was a direct target gene of miR-150-5p in CRC cells. Moreover, effect of CDO1 on ferroptosis was regulated transcriptionally by c-Myb, overexpression of c-Myb reduce CDO1 expression and enhance the GPX4 levels. The animal models confirmed that regulatory effect of SNHG4 on miR-150-5p and c-Myb after inducing ferroptosis. We concluded that SNHG4 inhibited Erastin-induce ferroptosis in CRC, this effect is via sponging miR-150-5p to regulate c-Myb expression, and activated CDO1/GPX4 axis. These findings provide insights into the regulatory mechanism of SNHG4 on ferroptosis.

Depicting the Profile of METTL3-Mediated lncRNA m6A Modification Variants and Identified SNHG7 as a Prognostic Indicator of MNNG-Induced Gastric Cancer

As a representative example of an environmental chemical carcinogen, MNNG exposure is closely associated with the onset of gastric cancer (GC) where N6-methyladenosine (m6A) RNA methylation tends to be the critical epigenetic event. However, the effect of m6A modification on long non-coding RNAs (lncRNAs) in MNNG-induced GC onset is still unclear. To address the above issue, based on the Methylated RNA immunoprecipitation sequencing (MeRIP-seq) data of MNNG-induced malignant cells (MCs) and GC cells, we comprehensively analyzed the MNNG exposure-associated vital lncRNAs. MeRIP-seq analysis identified 1432 lncRNA transcripts in the MC cell, and 3520 lncRNA transcripts were found to be m6A modified in the GC cell, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that MNNG exposure could spark cellular localization change, which might be the critical cellular note variation for malignant transformation. We demonstrated that METTL3 is responsible for N6 methylation of lncRNAs and identified SNHG7 as a downstream target of METTL3. More importantly, we observed that SNHG7 was progressively up-regulated during gastric carcinogenesis by MNNG exposure. Finally, we investigated SNHG7 expression in different stages of GC malignancies and found that elevated SNHG7 expression correlated with advanced clinical features and poor prognosis in GC. In conclusion, our study found for the first time that METTL3 regulates the m6A methylation level of lncRNA SNHG7 and its expression in MNNG exposure-induced GC, suggesting that SNHG7 as a predictive biomarker or therapeutic target for GC.

Deleted in lymphocytic leukemia 2 (DLEU2): a possible biomarker that holds promise for future diagnosis and treatment of cancer

The mechanism of deleted in lymphocytic leukemia 2 (DLEU2)-long non-coding RNA in tumors has become a major point of interest in recent research related to the occurrence and development of a variety of tumors. Recent studies have shown that the long non-coding RNA DLEU2 (lncRNA-DLEU2) can cause abnormal gene or protein expression by acting on downstream targets in cancers. At present, most lncRNA-DLEU2 play the role of oncogenes in different tumors, which are mostly associated with tumor characteristics, such as proliferation, migration, invasion, and apoptosis. The data thus far show that because lncRNA-DLEU2 plays an important role in most tumors, targeting abnormal lncRNA-DLEU2 may be an effective treatment strategy for early diagnosis and improving the prognosis of patients. In this review, we integrated lncRNA-DLEU2 expression in tumors, its biological functions, molecular mechanisms, and the utility of DLEU2 as an effective diagnostic and prognostic marker of tumors. This study aimed to provide a potential direction for the diagnosis, prognosis, and treatment of tumors using lncRNA-DLEU2 as a biomarker and therapeutic target.

LncRNA SNHG6 role in clinicopathological parameters in cancers

RNA sequencing has revealed that a substantial portion of the human genome undergoes transcription, yet a minimal fraction of these transcripts translates into proteins. LncRNAs, RNA molecules less than 200 nt in length, once deemed as transcriptional noise, have now emerged as crucial regulators of numerous cellular processes. This review focuses on the lncRNA SNHG6, aiming to elucidate its biogenesis, the pivotal roles it plays, and its mechanisms in facilitating the hallmarks of cancer. A comprehensive literature review and analysis were undertaken to delve into the biogenesis of SNHG6, its roles in cellular processes, and the mechanisms through which it contributes to the hallmarks of cancer. SNHG6 is a notable lncRNA, observed to be overexpressed in various cancer types; its perturbation has been linked to tumor progression, emphasizing its significance in oncogenesis. This lncRNA contributes to a range of cellular aberrations, influencing transcriptional, post-transcriptional, and epigenetic processes of mRNA, ultimately driving cancerous transformations. LncRNA SNHG6 serves as a potential biomarker and therapeutic target due to its association with tumorigenesis. Understanding its mechanism and role in cancer can pave the way for novel diagnostic and therapeutic strategies.

Long Non-coding RNA SNHG7 Suppresses Inflammation and Apoptosis of Chondrocytes Through Inactivating of p38 MAPK Signaling Pathway in Osteoarthritis

This study aims to explore the molecular mechanism of LncRNA SNHG7 in Osteoarthritis (OA). Cartilage tissues of OA patients or patients with trauma or amputation were collected. Compared to normal cartilage tissues, SNHG7 was downregulated while miR-324-3p was upregulated in cartilage tissues of OA patients. IL-1β was used to induce damage to chondrocytes and treatment with IL-1β reduced SNHG7 expression in OA chondrocytes. In IL-1β-treated OA chondrocytes, SNHG7 overexpression reduced the levels of TNF-α and IL-6, inhibited cell apoptosis, and increased cell viability. Additionally, the luciferase reporter assay proved that SNHG7 upregulated dual-specificity phosphatase 1 (DUSP1) by sponging miR-324-3p, thereby inactivating the p38 MAPK signaling pathway by regulating the miR-324-3p/DUSP1 axis. Anisomycin (a p38 MAPK activator) enhanced OA chondrocytes inflammation, promoted cell apoptosis, and reduced cell viability; however, this was reversed by SNHG7 overexpression. This study demonstrates that the SNHG7/miR-324-3p/DUSP1 axis suppresses OA chondrocytes inflammation and apoptosis by inhibiting the p38 MAPK signaling pathway. Thus, this study indicates that SNHG7 is a novel target for OA treatment.

Role of long non-coding RNAs in pancreatic cancer pathogenesis and treatment resistance- A review

Pancreatic cancer (PC) is one of the deadliest cancers associated with poor prognosis. The lack of reliable means of early cancer detection contributes to this disease's dismal prognosis. Long non-coding RNAs (LncRNAs) are protein-free RNAs produced by genome transcription; they play critical roles in gene expression regulation, epigenetic modification, cell proliferation, differentiation, and reproduction. Recent research has shown that lncRNAs play important regulatory roles in PC behaviors, in addition to their recently found functions. Several in-depth investigations have shown that lncRNAs are strongly linked to PC development and progression. Here, we discuss how lncRNAs, which are often overlooked, play many roles as regulators in the molecular mechanism underlying PC. This review also discusses the involved LncRNAs in PC pathogenesis and treatment resistance.

LncRNA SNHG4 Modulates EMT Signal and Antitumor Effects in Endometrial Cancer through Transcription Factor SP-1

Long non-coding RNAs (lncRNAs) are implicated in the initiation and progression of a variety of tumors, including endometrial cancer. However, the mechanisms of lncRNA in endometrial cancer formation and progression remain largely unknown. In this study, we confirmed that the lncRNA SNHG4 is upregulated in endometrial cancer and correlates with lower survival rates in endometrial cancer patients. Knock-down of SNHG4 significantly reduced cell proliferation, colonization, migration, and invasion in vitro, as well as modulating the cell cycle and reduced tumor growth of endometrial cancer in vivo. In addition, the effect of SNHG4 by the transcription factor SP-1 was confirmed in vitro. We found in this study that SNHG4/SP-1 plays an important role in endometrial cancer progression and may be used as a potential therapeutic and prognostic biomarker for endometrial cancer.

The Diagnostic and Therapeutic Role of snoRNA and lincRNA in Bladder Cancer

Bladder cancer is one of the most common malignancies of the urinary tract and can be divided into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Although the means of diagnosis and treatment have continually improved in recent years, the recurrence rate of bladder cancer remains high, and patients with MIBC typically have an unfavourable prognosis and a low quality of life. Emerging evidence demonstrates that long noncoding RNAs play a crucial role in the carcinogenesis and progression of bladder cancer. Long intergenic noncoding RNAs (lincRNAs) are a subgroup of long noncoding RNAs (lncRNAs) that do not overlap protein-coding genes. The potential role of lincRNAs in the regulation of gene expression has been explored in depth in recent years. Small nucleolar RNAs (snoRNAs) are a class of noncoding RNAs (ncRNAs) that mainly exist in the nucleolus, are approximately 60-300 nucleotides in length, and are hosted inside the introns of genes. Small nucleolar RNA host genes (SNHGs) have been associated with the origin and development of bladder cancer. In this review, we aim to comprehensively summarize the biological functions of these molecules in bladder cancer.

Long Non-Coding RNA SNHG4 Expression in Women with Endometriosis: A Pilot Study

BACKGROUND

Endometriosis is a chronic disease of the genital organs that mainly affects women of reproductive age. The analysis of long non-coding RNA (lncRNA) in endometriosis is a novel field of science. Recently, attention has been drawn to SNHG4, which is incorrectly expressed in various human diseases, including endometriosis.

AIM

The aim of this pilot study was to analyze the expression of lncRNA small nucleolar RNA host gene 4 (SNHG4) and to investigate its significance in endometriosis.

MATERIAL AND METHODS

LncRNA SNHG4 expression was investigated in paraffin blocks in endometriosis patients (n = 100) and in endometriosis-free controls (n = 100) using a real-time PCR assay.

RESULTS

This study revealed a higher expression of SNHG4 in endometriosis patients than in controls. A statistically significant relationship between expression level and SNHG4 was found in relation to The Revised American Society for Reproductive Medicine classification of endometriosis, 1996, in the group of patients with endometriosis.

CONCLUSION

This pilot study has revealed that gene expression in SNHG4 plays an important role in the pathogenesis of endometriosis.

New Insights into lncRNAs in Aβ Cascade Hypothesis of Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia, but its pathogenesis is not fully understood, and effective drugs to treat or reverse the progression of the disease are lacking. Long noncoding RNAs (lncRNAs) are abnormally expressed and deregulated in AD and are closely related to the occurrence and development of AD. In addition, the high tissue specificity and spatiotemporal specificity make lncRNAs particularly attractive as diagnostic biomarkers and specific therapeutic targets. Therefore, an in-depth understanding of the regulatory mechanisms of lncRNAs in AD is essential for developing new treatment strategies. In this review, we discuss the unique regulatory functions of lncRNAs in AD, ranging from Aβ production to clearance, with a focus on their interaction with critical molecules. Additionally, we highlight the advantages and challenges of using lncRNAs as biomarkers for diagnosis or therapeutic targets in AD and present future perspectives in clinical practice.

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.

Mir-34a: a regulatory hub with versatile functions that controls osteosarcoma networks

Osteosarcoma (OS) is one of the most prevalent and highly aggressive bone malignancies. The treatment strategies of OS is under standard regimens, including surgical resection, chemotherapy, and other adjuvant therapy. However, the 5-year survival rate is still unsatisfactory. Previous studies have demonstrated that the expression of miR-34a decreases in osteosarcoma, which is involved in regulating numerous genes directly or indirectly at the post-transcriptional level and other pathways. Thus, miR-34a plays an important role in mediating OS cell proliferation, differentiation, migration, and apoptosis, and might be a pivotal biomarker for OS with diagnostic and therapeutic potentials. In this review, we aim to summarize the relationship between miR-34a and OS, with an emphasis on the specific mechanisms in OS development referring to miR-34a. Moreover, the potential role of miR-34a as a diagnostic, prognostic, and therapeutic candidate for OS would be presented in detail. However, the molecular mechanisms related to miR-34a and OS remain elusive, and more investigations are needed to reach a comprehensive understanding.

The role of long non-coding RNA FGD5-AS1 in cancer

Long noncoding RNAs (lncRNAs) refers to a class of RNAs that have at least 200 nucleotides and do not encode proteins, and the relationship between lncRNA and cancer has recently attracted considerable research attention. The lncRNA FGD5-AS1 is a newly discovered lncRNA with a length of 3772 nucleotides. Studies have found that FGD5-AS1 is abnormally highly expressed in many cancer tissues and was closely related to the lymph node metastasis, tumor invasion, survival time, and recurrence rate of various cancers. Mechanistic analyses show that FGD5-AS1 can stabilize mRNA expression by sponging miRNA, which not only induces cancer cell proliferation, metastasis, invasion, and chemoresistance in vitro, but also promotes tumor growth and metastasis in vivo. In addition, FGD5-AS1 can serve as a diagnostic or prognostic marker for a variety of cancers. This review demonstrates the clinical significance of FGD5-AS1 in human cancer and its role in tumorigenesis and tumor progression.

LINC00922 acts as a novel oncogene in gastric cancer

Background

Long non-coding RNAs (lncRNAs) have been discovered to participate in various cancer developments. However, the biological function of lncRNAs associated with gastric cancer (GC) has not been fully elucidated.

Methods

Quantitative RT-PCR (qRT-PCR) assay was performed to measure lncRNAs, microRNAs (miRNAs) and message RNA (mRNA) expression. Cell Counter Kit-8 (CCK-8), clone formation, wound healing, and transwell assays were performed to investigate cell proliferation, migration, invasion, and apoptosis. Fluorescence in situ hybridization (FISH) assay was used to analyze LINC00922 in either the cytoplasm or nucleus. The potential binding among lncRNA, miRNA, and mRNA was evidenced by bioinformatics, luciferase reporter assay. Mouse-xenograft experiments were used to explore the tumorigenesis in vivo.

Results

LINC00922 was upregulated in GC, and high LINC00922 expression was associated with poor prognosis. Inhibition of LINC00922 suppressed GC cell proliferation, migration, invasion, and activated cell apoptosis in vitro and inhibited tumorigenesis in vivo. Besides, LINC00922 was markedly located in the cytoplasm. The mechanistic analysis demonstrated that LINC00922 acted as a sponge of miR-204-5p, thereby inhibiting the expression of the target gene-High Mobility Group AT-hook 2 (HMGA2).

Conclusion

LINC00922 accelerated the progression of GC by miR-204-5p/HMGA2 axis. These findings support LINC00922 may be a promising option for the diagnosis and therapy of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02569-3.

Establishment and validation of a prognostic model based on HRR-related lncRNAs in colon adenocarcinoma

BACKGROUND

Colon cancer (CRC) is the second leading cause of cancer-related death, and its 5-year survival rate is very low. Homologous recombination repair (HRR) is deficient in most colon cancer. Some long non-coding RNAs (lncRNAs) participate in tumorigenesis of colon cancer through the HRR pathway. We aim to establish a prognostic model based on the HRR-related lncRNAs, expecting to provide a new strategy for precision treatment development in colon cancer.

METHODS

Pearson's correlation was used to identify the HRR-related prognostic lncRNAs in the TCGA-COAD cohort. The TCGA-COAD cohort was randomized into the training set and the testing set. LASSO Cox regression was used to establish the model which was analyzed in the training set and validated in the testing set and the entire TCGA-COAD cohort. Finally, we explored the potential biological function of our model.

RESULTS

A prognostic model was established based on nineteen HRR-related lncRNAs in the training set. COAD patients were scored by the uniform formula and divided into high-risk and low-risk groups based on the median risk score. Patients with high-risk scores indicated poor prognosis in the training set, and the result was confirmed in the testing set and the entire TCGA-COAD cohort (all p < 0.01). Multivariable analysis suggested that our model was an independent factor for overall survival in COAD. The area under the curve (AUC) and C-index indicated that our model had better predictive efficiency than other indicators in the TCGA-COAD cohort. Functional enrichment analysis suggested that our model was associated with the MAPK pathway in COAD. Besides, our model was positively correlated with the HRD scores.

CONCLUSION

A new prognostic model was established based on nineteen HRR-related lncRNAs which had excellent predictive efficiency on the prognosis of COAD. This prognostic model may provide a new strategy for prognostic prediction of COAD patients.

Long noncoding RNA SNHG17: a novel molecule in human cancers

Many studies in recent years have found that dysregulation of long non-coding RNAs (lncRNAs) can contribute to disease. Small nucleolar RNA host gene 17 (SNHG17) is a novel cancer-related lncRNA of the SNHG family which is highly expressed in various tumors and may exert oncogenic functions. Several studies have demonstrated that SNHG17 is closely related to the proliferation, migration, invasion, apoptosis, and chemical drug resistance of tumor cells, and clinical studies have found an association between high SNHG17 expression and poor prognosis. In this review, we summarize relevant studies investigating SNHG17, focusing on its biological function as well as its potential value for clinical applications.

Temporal Gene Expression Profiles Reflect the Dynamics of Lymphoid Differentiation

Understanding the emergence of lymphoid committed cells from multipotent progenitors (MPP) is a great challenge in hematopoiesis. To gain deeper insight into the dynamic expression changes associated with these transitions, we report the quantitative transcriptome of two MPP subsets and the common lymphoid progenitor (CLP). While the transcriptome is rather stable between MPP2 and MPP3, expression changes increase with differentiation. Among those, we found that pioneer lymphoid genes such as Rag1, Mpeg1, and Dntt are expressed continuously from MPP2. Others, such as CD93, are CLP specific, suggesting their potential use as new markers to improve purification of lymphoid populations. Notably, a six-transcription factor network orchestrates the lymphoid differentiation program. Additionally, we pinpointed 24 long intergenic-non-coding RNA (lincRNA) differentially expressed through commitment and further identified seven novel forms. Collectively, our approach provides a comprehensive landscape of coding and non-coding transcriptomes expressed during lymphoid commitment.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

Long noncoding RNA SNHG4: a novel target in human diseases

Recently, long noncoding RNAs (lncRNAs) have attracted great attention from researchers. LncRNAs are non-protein-coding RNAs of more than 200 nucleotides in length. Multiple studies have been published on the relationship between lncRNA expression and the progression of human diseases. LncRNA small nucleolar RNA host gene 4 (SNHG4), a member of the lncRNA SNHG family, is abnormally expressed in a variety of human diseases, including gastric cancer, renal cell carcinoma, glioblastoma, neuroblastoma, prostate cancer, colorectal cancer, osteosarcoma, cervical cancer, liver cancer, lung cancer, non-small-cell lung cancer, neonatal pneumonia, diabetic retinopathy, neuropathic pain, acute cerebral infarction, acute myeloid leukaemia, and endometriosis. In this paper, the structure of SNHG4 is first introduced, and then studies in humans, animal models and cells are summarized to highlight the expression and function of SNHG4 in the above diseases. In addition, the specific mechanism of SNHG4 as a competing endogenous RNA (ceRNA) is discussed. The findings indicate that SNHG4 can be used as a biomarker for disease prognosis evaluation and as a potential target for disease diagnosis and treatment.

LncRNA SNHG7 Regulates Gastric Cancer Progression by miR-485-5p

Background

Long noncoding ribonucleic acids (lncRNAs) were closely related to the development of gastric cancer. This study investigated the effect of SNHG7 on gastric cancer progression and its potential molecular mechanism.

Methods

SNHG7 and microRNA-485-5p (miR-485-5p) expressions in gastric cancer tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8), wound healing, and transwell experiments were used to detect cell proliferation, migration, and invasion. The dual luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Pearson's correlation analysis were used to confirm the relationship between SNHG7 and miR-485-5p.

Results

SNHG7 expression was increased in human gastric cancer tissues and cells. Knockdown of SNHG7 could notably inhibit the gastric cancer cells proliferation, migration, and invasion. The dual-luciferase reporter assay and RIP experiments proved that miR-485-5p was a direct target of SNHG7. At the same time, further experiments demonstrated that miR-485-5p inhibition reversed the suppression of SNHG7 knockdown on gastric cancer cells proliferation, migration, and invasion.

Conclusions

SNHG7 knockdown could hamper gastric cancer progression via inhibiting miR-485-5p expression, providing a novel understanding for gastric cancer development.

Long Noncoding RNA Small Nuclear RNA Host Gene 7 Knockdown Protects Mouse Cardiac Fibroblasts Against Myocardial Infarction by Regulating miR-455-3p/Platelet-Activating Factor Receptor Axis

ABSTRACT

Myocardial infarction (MI) is a leading cause of heart failure all over the world. Long noncoding RNAs have been reported to be associated with the development of MI. In this article, we aimed to explore the effects of long noncoding RNA small nuclear RNA host gene 7 (SNHG7) on MI and the possible mechanism. In this study, an MI model was established by ligating the left anterior descending coronary artery of mice. Cardiac fibroblasts (CFs) derived from neonatal mice were activated by angiotensin II (Ang-II) treatment. The expression of SNHG7 and miR-455-3p was examined by quantitative real-time polymerase chain reaction, and protein levels of platelet-activating factor receptor (PTAFR) and fibrosis-related proteins were analyzed by western blot assay. Cell apoptosis of CFs was monitored by flow cytometry. Enzyme-linked immunosorbent assay was performed to evaluate inflammatory responses in CFs. Moreover, dual-luciferase reporter assay was used to confirm the target relationship between miR-455-3p and SNHG7 or PTAFR. LncRNA SNHG7 and PTAFR were upregulated, whereas miR-455-3p was downregulated in cardiac tissues of mice with MI and Ang-II-induced CFs. SNHG7 depletion or miR-455-3p overexpression attenuated Ang-II-induced apoptosis, fibrosis, and inflammation in CFs, which was severally weakened by miR-455-3p inhibition or PTAFR upregulation. LncRNA SNHG7 targeted miR-455-3p, and PTAFR was a target of miR-455-3p. LncRNA SNHG7 depletion exerted protective roles in apoptosis, fibrosis, and inflammation in Ang-II-induced CFs by regulating miR-455-3p/PTAFR axis, providing a potential molecular target for MI therapy.

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 Noncoding RNA Small Nucleolar Host Gene: A Potential Therapeutic Target in Urological Cancers

The incidence of urological cancer has been gradually increasing in the last few decades. However, current diagnostic tools and treatment strategies continue to have limitations. Substantial evidence shows that long noncoding RNAs (lncRNAs) play essential roles in carcinogenesis and the progression, treatment response and prognosis of multiple human cancers, including urological cancers, gastrointestinal tumours, reproductive cancers and respiratory neoplasms. LncRNA small nucleolar RNA host genes (SNHGs), a subgroup of lncRNAs, have been found to be dysregulated in tumour cell biology. In this review, we summarize the impacts of lncRNA SNHGs in urological malignancies and the underlying mechanisms.

Long non-coding RNA small nucleolar RNA host gene 7 facilitates the proliferation, migration, and invasion of esophageal cancer cells by regulating microRNA-625

Background

Esophageal cancer (EC) is a highly aggressive malignant tumor, of which esophageal squamous cell carcinoma (ESCC) constitutes the main subtype. Long non-coding RNA (lncRNA) small nucleolar RNA host gene 7 (SNHG7) has been extensively studied in many tumors and has been confirmed to be an oncogene; however, it has yet to be investigated in an ESCC study. Therefore, this study intended to uncover the role of SNHG7 in ESCC.

Methods

Quantitative real-time polymerase chain reaction was applied to measure the expression levels of SNHG7 and miR-625 in ESCC tumor tissues and cell lines. Cell Counting Kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay, scratch assay, and Transwell assay were conducted to assess the proliferation, migration, and invasion ESCC cell. We verified the interaction between SNHG7 and miR-625 by performing the dual luciferase reporter gene experiment.

Results

Compared to that in adjacent normal tissues and HET1A cell lines, the expression level of SNHG7 in ESCC tumor tissues and ESCC cell lines was up-regulated, while the expression level of miR-625 was down-regulated. ESCC cell proliferation, migration, and invasion were significantly promoted by SNHG7 overexpression but inhibited by silencing of SNHG7. Further, luciferase reporter gene experiments confirmed that SNHG7 interacted with miR-625, and rescue experiments showed that SNHG7 promoted the malignant phenotype by inhibiting miR-625.

Conclusions

SNHG7 is up-regulated in ESCC tumor tissues and cell lines, while miR-625 is expressed at a low level. SNHG7 is able to facilitate the proliferation, migration, and invasion of ESCC cells by targeting miR-625.

Long Non-coding RNAs in Gammaherpesvirus Infections: Their Roles in Tumorigenic Mechanisms

Long non-coding RNAs (lncRNAs) regulate gene expression at the epigenetic, transcriptional, or posttranscriptional level by interacting with protein, DNA, and RNA. Emerging evidence suggests that various lncRNAs are abnormally expressed and play indispensable roles in virus-triggered cancers. Besides, a growing number of studies have shown that virus-encoded lncRNAs participate in tumorigenesis. However, the functions of most lncRNAs in tumors caused by oncogenic viruses and their underlying mechanisms remain largely unknown. In this review, we summarize current findings regarding lncRNAs involved in cancers caused by Epstein–Barr virus (EBV) and Kaposi’s sarcoma herpesvirus (KSHV). Additionally, we discuss the contribution of lncRNAs to tumor occurrence, development, invasion, and metastasis; the roles of lncRNAs in key signaling pathways and their potential as biomarkers and therapeutic targets for tumor diagnostics and treatment.

LncRNA SNHG7 alleviates IL-1β-induced osteoarthritis by inhibiting miR-214-5p-mediated PPARGC1B signaling pathways

BACKGROUND

As a common joint disease, osteoarthritis (OA) is the main cause of limited joint mobility and disability. The role of lncRNAs in the regulation of OA is increasingly discovered. Therefore, further exploring the function of SNHG7 in OA is of great significance for understanding its occurrence and development.

METHODS

We used interleukin-1β (IL-1β) to treat to establish an OA model primary on chondrocytes in vitro, and gain- and loss of function assays of SNHG7 and miR-214-5p were conducted. The cell viability and apoptosis of chondrocytes were detected by CCK8 assay, BrdU assay and flow cytometry. The inflammatory cytokines (IL-1β, IL-6 and TNF-α), NLRP3 inflammasome, protein level of PPARGC1B, PPARγ, P38 and NF-κB were determined by RT-PCR and/or western blot.

RESULTS

The results showed that SNHG7 was distinctly downregulated, while miR-214-5p was significantly upregulated in OA patients and primary chondrocytes treated with IL-1β. In addition, SNHG7 enhanced cell viability, inhibited apoptosis and inflammation of IL-1β-mediated chondrocytes. In contrast, miR-214-5p upregulation reduced viability, promoted apoptosis and inflammation of chondrocytes. Mechanistically, SNHG7 served as a competitive endogenous RNA by sponging miR-214-5p, which targeted PPARGC1B. Besides, the results of the compensation experiment affirmed that miR-214-5p attenuates SNHG7-mediated protective effects on IL-1β-mediated chondrocytes against apoptosis and inflammation, and activating PPARγ pathway markedly dampened the cytotoxic effects of miR-214-5p.

CONCLUSIONS

Collectively, The above results confirmed that SNHG7 prevents IL-1β induced OA by inhibiting NLRP3 inflammasome and apoptosis through miR-214-5p/PPARGC1B axis.

The lncRNA LINC00691Functions as a ceRNA for miRNA-1256 to Suppress Osteosarcoma by Regulating the Expression of ST5

Introduction

Osteosarcoma is the most common primary malignant tumor in children and young patients. Although neoadjuvant chemotherapy and surgery could improve the prognosis of these patients, treatment outcomes are poor because of its low early diagnosis rate and high degree of malignancy as well as its tendency for early metastasis. In the field of osteosarcoma, lncRNAs have become a hot spot for studying the molecular mechanisms driving malignant biological characteristics and exploring effective treatment methods. An lncRNA is a long noncoding RNA lacking protein-encoding ability, and in its RNA form, it regulates various gene expression processes, such as epigenetic regulation, transcriptional regulation, and posttranscriptional regulation. LncRNAs play an important role in tumorigenesis and metastasis.

Methods

We used bioinformatics software to analyze the data in geo database. CCK-8 and Transwell were used to detect the effect of lncRNA LINC00691 on the proliferation and migration of osteosarcoma cells. The target gene of LINC00691 was detected by bioinformatics analysis and RNA pull down.

Results

In this study, we identified the lncRNA LINC00691 and confirmed its expression in osteosarcoma cells through GEO database analysis. Expression analysis showed that the levels of lncRNA LINC00691 in osteosarcoma cells were decreased compared to those of control cells. Overexpression of LINC00691 could inhibit the proliferation, migration, invasion, and induction of G1 cell cycle arrest in osteosarcoma cells, which was shown through in vitro and in vivo studies. Using bioinformatics analysis, RNA pull down experiments and luciferase reporter gene detection assays, we found that LINC00691 regulated ST5 expression by binding miR-1256. LINC00691 overexpression inhibited EMT by promoting the expression of E-cadherin and increasing the expression of ZEB1, Snail, and Fibronectin.

Conclusion

These results suggested that overexpressed LINC00691 promoted the expression of ST5 by regulating the function of miR-1256 through a ceRNA mechanism. The LINC00691/miR-1256/ST5 pathway plays an important role in the progression and metastasis of osteosarcoma and represents a good therapeutic target.

Joint analysis of lncRNA m6A methylome and lncRNA/mRNA expression profiles in gastric cancer

Background

N ⁶-methyladenosine (m⁶A) modification might be closely associated with the genesis and development of gastric cancer (GC). Currently, the evidence established by high-throughput assay for GC-related m⁶A patterns based on long non-coding RNAs (lncRNAs) remains limited. Here, a joint analysis of lncRNA m⁶A methylome and lncRNA/mRNA expression profiles in GC was performed to explore the regulatory roles of m⁶A modification in lncRNAs.

Methods

Three subjects with primary GC were enrolled in our study and paired sample was randomly selected from GC tissue and adjacent normal tissue for each case. Methylated RNA Immunoprecipitation NextGeneration Sequencing (MeRIP-Seq) and Microarray Gene Expression Profiling was subsequently performed. Then co-expression analysis and gene enrichment analysis were successively conducted.

Results

After data analysis, we identified 191 differentially m⁶A-methylated lncRNAs, 240 differentially expressed lncRNAs and 229 differentially expressed mRNAs in GC. Furthermore, four differentially m⁶A-methylated and expressed lncRNAs (dme-lncRNAs) were discovered including RASAL2-AS1, LINC00910, SNHG7 and LINC01105. Their potential target genes were explored by co-expression analysis. And gene enrichment analysis suggested that they might influence the cellular processes and biological behaviors involved in mitosis and cell cycle. The potential impacts of these targets on GC cells were further validated by CCLE database and literature review.

Conclusions

Four novel dme-lncRNAs were identified in GC, which might exert regulatory roles on GC cell proliferation. The present study would provide clues for the lncRNA m⁶A methylation-based research on GC epigenetic etiology and pathogenesis.

Identification of Long Non-Coding RNA SNHG Family as Promising Prognostic Biomarkers in Acute Myeloid Leukemia

Background

Small nucleolar RNA host gene (SNHG) family members are newly recognized lncRNAs, which have been revealed to be oncogenes in several cancers. However, little studies investigated the expression and clinical implications of SNHGs in AML.

Methods

Herein, we systemically determined the prognostic role of the expression of SNHG family members in acute myeloid leukemia (AML).

Results

Among the expression of all SNHG family members, we identified that only SNHG7 and SNHG12 expression were found to have prognostic effects on overall survival (OS) and leukemia-free survival (LFS) in AML by Cox regression univariate analysis. Furthermore, Kaplan-Meier analysis showed that SNHG7 higher-expressed cases had markedly longer OS and LFS time than SNHG7 lower-expressed cases, whereas SNHG12 higher-expressed cases had markedly shorter OS and LFS time than SNHG12 lower-expressed cases. Interestingly, SNHG7 and SNHG12 expression were also associated with several prognosis-related clinical/molecular features such as white blood cell counts, FAB/cytogenetic classifications, IDH1 mutation, RUNX1 mutation, and NPM1 mutation. Despite the associations, Cox regression multivariate analysis confirmed the independent prognostic impact of SNHG7 and SNHG12 expression in AML. Notably, we further validated that both SNHG7 and SNHG12 expression was significantly increased in newly diagnosed AML patients.

Conclusion

Our findings demonstrated that SNHG7 and SNHG12 expression act as independent prognostic indicators in AML.

PTEN: What we know of the function and regulation of this onco-suppressor factor in bladder cancer?

Bladder cancer accounts for high morbidity and mortality around the world and its incidence rate is suggested to be higher in following years. A number of factors involve in bladder cancer development such as lifestyle and drugs. However, it appears that genetic factors play a significant role in bladder cancer development and progression. Phosphatase and tensin homolog (PTEN) is a cancer-related transcription factor that is corelated with reduced proliferation and invasion of cancer cells by negatively targeting PI3K/Akt/mTOR signaling pathway. In the present review, we aimed to explore the role of PTEN in bladder cancer cells and how upstream modulators affect PTEN in this life-threatening disorder. Down-regulation of PTEN is associated with poor prognosis, chemoresistance and progression of cancer cells. Besides, microRNAs, long non-coding RNAs, circular RNAs and other molecular pathways such as NF-kB are able to target PTEN in bladder cancer cells. Notably, anti-tumor drugs such as kaempferol, β-elemene and sorafenib upregulate the expression of PTEN to exert their inhibitory effects on bladder cancer cells.