SNHG15 functions as a tumor suppressor in thyroid cancer

Diagnostic value of long noncoding RNA SNHG15 in gastric cancer: in vitro and in silico studies

LncRNA SNHG15 has been recognized as the main factor in the progression of various cancer types. However, the underlying mechanisms are not well clarified. This research aimed to explore the diagnostic potential of SNHG15 in gastric cancer (GC) patients and also the effects of SNHG15-miRNA-mRNA network in GC pathobiology. The expression level of SNHG15 in GC tissues and adjacent normal tissues (ANTs) was evaluated by qRT-PCR and also considered in relation to clinicopathologic factors. The ROC curve was explored to consider the specificity and sensitivity of SNHG15. Gene ontology functional annotation and KEGG pathway analysis were performed in order to predict the effects of SNHG15-miRNA-mRNA network in GC pathobiology. SNHG15 was overexpressed in GC tissues compared to ANTs (fold change= 3.87 and P-value = 0.0022). The SNHG15 expression level was not significantly associated with clinicopathologic factors. ROC curve indicated the specificity of 63.51 and sensitivity of 79.73 and the AUC of 0.744 (P-value < 0.0001). Further gene network analysis revealed that SNHG15 interacts with has-miR-613, has-miR-542-3p, and has-miR-1236-3p, and may be involved in the GC pathobiology by affecting the EGFR tyrosine kinase inhibitor resistance, HIF-1 signaling pathway, and VEGF signaling pathway. It can be concluded that SNHG15 may be a diagnostic factor in GC and may contribute in a variety of cancer-related signaling pathways.

Advances and challenges in thyroid cancer: The interplay of genetic modulators, targeted therapies, and AI-driven approaches

Thyroid cancer continues to exhibit a rising incidence globally, predominantly affecting women. Despite stable mortality rates, the unique characteristics of thyroid carcinoma warrant a distinct approach. Differentiated thyroid cancer, comprising most cases, is effectively managed through standard treatments such as thyroidectomy and radioiodine therapy. However, rarer variants, including anaplastic thyroid carcinoma, necessitate specialized interventions, often employing targeted therapies. Although these drugs focus on symptom management, they are not curative. This review delves into the fundamental modulators of thyroid cancers, encompassing genetic, epigenetic, and non-coding RNA factors while exploring their intricate interplay and influence. Epigenetic modifications directly affect the expression of causal genes, while long non-coding RNAs impact the function and expression of micro-RNAs, culminating in tumorigenesis. Additionally, this article provides a concise overview of the advantages and disadvantages associated with pharmacological and non-pharmacological therapeutic interventions in thyroid cancer. Furthermore, with technological advancements, integrating modern software and computing into healthcare and medical practices has become increasingly prevalent. Artificial intelligence and machine learning techniques hold the potential to predict treatment outcomes, analyze data, and develop personalized therapeutic approaches catering to patient specificity. In thyroid cancer, cutting-edge machine learning and deep learning technologies analyze factors such as ultrasonography results for tumor textures and biopsy samples from fine needle aspirations, paving the way for a more accurate and effective therapeutic landscape in the near future.

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.

Long noncoding RNA SNHG15: A promising target in human cancers

As oncogenes or tumor suppressor genes, lncRNAs played an important role in tumorigenesis and the progression of human cancers. The lncRNA SNHG15 has recently been revealed to be dysregulated in malignant tumors, suggesting the aberrant expression of which contributes to clinical features and regulates various oncogenic processes. We have selected extensive literature focused on SNHG15 from electronic databases, including studies relevant to its clinical significance and the critical events in cancer-related processes such as cell proliferation, apoptosis, autophagy, metastasis, and drug resistance. This review summarized the current understanding of SNHG15 in cancer, mainly focusing on the pathological features, known biological functions, and underlying molecular mechanisms. Furthermore, SNHG15 has been well-documented to be an effective diagnostic and prognostic marker for tumors, offering novel therapeutic interventions in specific subsets of cancer cells.

The Role of SNHG15 in the Pathogenesis of Hepatocellular Carcinoma

Long non-coding RNAs (lncRNAs) are transcripts of more than 200 nucleotides which cannot be translated into proteins. Small nucleolar RNA host gene 15 (SNHG15) is a lncRNA whose dysregulation has been found to have an important impact on carcinogenesis and affect the prognosis of cancer patients in various cancer types. Hepatocellular carcinoma (HCC) is one of the most common cancers with a poor long-term prognosis, while the best prognostic factor of the disease is its early diagnosis and surgery. Consequently, the investigation of the mechanisms of hepatocarcinogenesis, as well as the discovery of efficient molecular markers and therapeutic targets are of great significance. An extensive literature search was performed in MEDLINE in order to identify clinical studies that tried to reveal the role of SNHG15 in HCC. We used keywords such as ‘HCC’, ‘hepatocellular carcinoma’, ‘SNHG15’ and ‘clinical study’. Finally, we included four studies written in English, published during the period 2016–2021. It was revealed that SNHG15 is related to the appearance of HCC via different routes and its over-expression affects the overall survival of the patients. More assays are required in order to clarify the potential role of SNHG15 as a prognostic tool and therapeutic target in HCC.

Identification of circulating biomarkers for differentiating patients with papillary thyroid cancers from benign thyroid tumors

BACKGROUND

This study aimed to identify the potential circulating biomarkers of protein, mRNAs, and long non-coding RNAs (lncRNAs) to differentiate the papillary thyroid cancers from benign thyroid tumors.

METHODS

The study population of 100 patients was classified into identification (10 patients with papillary thyroid cancers and 10 patients with benign thyroid tumors) and validation groups (45 patients with papillary thyroid cancers and 35 patients with benign thyroid tumors). The Sengenics Immunome Protein Array-combined data mining approach using the Open Targets Platform was used to identify the putative protein biomarkers, and their expression validated using the enzyme-linked immunosorbent assay. Next-generation sequencing by Illumina HiSeq was used for the detection of dysregulated mRNAs and lncRNAs. The website Timer v2.0 helped identify the putative mRNA biomarkers, which were significantly over-expressed in papillary thyroid cancers than in adjacent normal thyroid tissue. The mRNA and lncRNA biomarker expression was validated by a real-time polymerase chain reaction.

RESULTS

Although putative protein and mRNA biomarkers have been identified, their serum expression could not be confirmed in the validation cohorts. In addition, seven lncRNAs (TCONS_00516490, TCONS_00336559, TCONS_00311568, TCONS_00321917, TCONS_00336522, TCONS_00282483, and TCONS_00494326) were identified and validated as significantly downregulated in patients with papillary thyroid cancers compared to those with benign thyroid tumors. These seven lncRNAs showed moderate accuracy based on the area under the curve (AUC = 0.736) of receiver operating characteristic in predicting the occurrence of papillary thyroid cancers.

CONCLUSIONS

We identified seven downregulated circulating lncRNAs with the potential for predicting the occurrence of papillary thyroid cancers.

High lncSNHG15 expression may predict poor cancer prognosis: a meta-analysis based on the PRISMA and the bio-informatics analysis

Background: SNHG15 has been reported to be aberrantly expressed in various tumor tissues and could serve as a promising prognostic cancer biomarker. Previous studies on SNHG15 yielded inconsistent results with insufficient sampling. Here, a meta-analysis was conducted to investigate the prognostic value of SNHG15 in multiple cancers. Methods: Relevant studies were retrieved from six electronic databases including PubMed, Cochrane Library, Google Scholar, Embase, Web of Science and China National Knowledge Infrastructure (CNKI). Fifteen publications comprising 1318 patients were included. The publication bias was identified by the Begg’s Test, and the sensitivity analysis was also performed. Results: The results demonstrated a positive correlation between high expression level of lncSNHG15 and short overall survival (hazard ratio (HR) = 2.07, 95% confidence interval (CI), 1.48–2.88; P<0.0001) and disease-free survival (DFS) (HR = 2.32, 95% CI, 1.53–3.53; P<0.0001). The analysis based on different cancer types showed that SNHG15 had the most prominent prognostic potential in Glioma (HR = 3.81; 95% CI, 0.84–42.69; P=0.28). Moreover, the high expression level of lncSNHG15 indicated advanced TNM stage (OR = 2.52; 95% CI, 1.33–4.76; P=0.00001), lymph node metastasis (OR = 2.41, 95% CI, 0.99–4.81; P=0.05), bigger tumor size (OR = 2.06; 95% CI, 1.03–4.13; P=0.04) and poor histological grade (OR = 2.62, 95% CI, 1.90–3.59; P<0.00001), yet no association with distant metastasis (OR = 1.64, 95% CI, 0.40–6.74; P=0.49), age (OR = 0.98, 95% CI, 0.78–1.22; P=0.84) and gender (OR = 0.9, 95% CI, 0.71–1.14; P=0.3838) was found. Its conclusions further confirmed by exploring TCGA databases. Conclusion: It revealed that lncSNHG15 might be a promising prognostic biomarker of multiple cancer types, especially in Glioma.

LncRNA SNHG15 Knockdown Protects Against OGD/R-Induced Neuron Injury by Downregulating TP53INP1 Expression via Binding to miR-455-3p

Cerebral ischemia-reperfusion (I/R) injury is the common symptom of ischemic stroke, which poses a heavy burden to human health. Long non-coding RNA (lncRNA) is indicated to be a critical regulator in cerebral ischemia. This study aims to reveal the effects of lncRNA small nucleolar RNA host gene 15 (SNHG15) on oxygen-glucose deprivation and reoxygenation (OGD/R)-induced neuron injury and underlying mechanism. The expression levels of SNHG15, microRNA-455-3p (miR-455-3p) and tumour protein p53 inducible nuclear protein 1 (TP53INP1) mRNA were determined by quantitative real time polymerase chain reaction in P12 cells. The protein levels of TP53INP1, cleaved caspase-3, caspase-3, B-cell lymphoma-2 and BCL2-associated x protein (Bax) were detected by western blot in P12 cells. Cell viability and apoptosis were revealed by cell counting kit-8 assay and flow cytometry analysis, respectively, in P12 cells. Caspase-3 activity, the levels of tumor necrosis factor-α and interleukin-1β and the production of reactive oxygen species (ROS) were severally determined by caspase-3 activity assay, Enzyme-linked immunosorbent assay and ROS detection assay in P12 cells. The binding relationship between miR-455-3p and SNHG15 or TP53INP1 was predicted by starbase online database, and identified by dual-luciferase reporter, RNA pull-down or RNA immunoprecipitation assay. SNHG15 expression and the mRNA and protein levels of TP53INP1 were dramatically upregulated, while miR-455-3p expression was apparently downregulated in OGD/R-induced PC12 cells. SNHG15 silencing hindered the effects of OGD/R treatment on cell viability, apoptosis, inflammation and oxidative in PC12 cells; however, these impacts were restored after miR-455-3p inhibitor transfection. Additionally, SNHG15 acted as a sponge of miR-455-3p and miR-455-3p bound to TP53INP1. SNHG15 contributed to OGD/R-induced neuron injury by regulating miR-455-3p/TP53INP1 axis, which provided a novel insight to study lncRNA-directed therapy in ischemia stoke.

The Expression of the Cancer-Associated lncRNA Snhg15 Is Modulated by EphrinA5-Induced Signaling

The Eph receptor tyrosine kinases and their respective ephrin-ligands are an important family of membrane receptors, being involved in developmental processes such as proliferation, migration, and in the formation of brain cancer such as glioma. Intracellular signaling pathways, which are activated by Eph receptor signaling, are well characterized. In contrast, it is unknown so far whether ephrins modulate the expression of lncRNAs, which would enable the transduction of environmental stimuli into our genome through a great gene regulatory spectrum. Applying a combination of functional in vitro assays, RNA sequencing, and qPCR analysis, we found that the proliferation and migration promoting stimulation of mouse cerebellar granule cells (CB) with ephrinA5 diminishes the expression of the cancer-related lncRNA Snhg15. In a human medulloblastoma cell line (DAOY) ephrinA5 stimulation similarly reduced SNHG15 expression. Computational analysis identified triple-helix-mediated DNA-binding sites of Snhg15 in promoters of genes found up-regulated upon ephrinA5 stimulation and known to be involved in tumorigenic processes. Our findings propose a crucial role of Snhg15 downstream of ephrinA5-induced signaling in regulating gene transcription in the nucleus. These findings could be potentially relevant for the regulation of tumorigenic processes in the context of glioma.

Long non-coding RNA SNHG15 in various cancers: a meta and bioinformatic analysis

Background

The snoRNA host gene SNHG15 produces a long non-coding RNA (lncRNA) with a short half-life and has been reported to be dysregulated in multiple cancers and has recently been found to be correlated with tumour progression. Therefore, this meta-analysis was performed to evaluate the generalised prognostic role of small nucleolar RNA host gene 15 (SNHG15) in malignancies, based on variable data from different studies.

Methods

Four public databases were used to identify eligible studies. The association between prognostic indicators and clinical features was extracted and pooled to estimate the hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs). Publication bias was measured using Begg’s test and Egger’s test, and the stability of pooled results were measured using sensitivity analysis. Additionally, an online database based on The Cancer Genome Atlas (TCGA) was screened to further validate our results. Ultimately, we predicted the molecular regulation of SNHG15 based on the public databases.

Results

In total, 11 studies including 1087 patients were ultimately enrolled in our meta-analysis. We found that SNHG15 overexpression was associated with worse overall survival (OS) and disease-free survival (DFS), and this was validated in the Gene Expression Profiling Interactive Analysis (GEPIA) cohort. Moreover, increased SNHG15 expression suggested advanced TNM stage and LNM, but was not associated with age, gender, or tumour size. No publication bias or instability of the results was observed. SNHG15 was significantly upregulated in seven cancers and elevated expression of SNHG15 indicated shorter OS and DFS in five malignancies based on the validation using the GEPIA cohort. Further functional prediction indicated that SNHG15 may participate in some cancer-related pathways.

Conclusions

Upregulation of lncRNA SNHG15 was notably associated with worse prognosis and clinical features, suggesting that SNHG15 might serve as a novel prognostic factor in various cancers.

LncUBE2R2-AS1 acts as a microRNA sponge of miR-302b to promote HCC progression via activation EGFR-PI3K-AKT signaling pathway

Hepatocellular carcinoma (HCC) is a main cause of cancer-related deaths globally. Long non-coding RNAs (lncRNAs) play important roles in diverse cancers. LncRNA-UBE2R2-AS1 has been reported to promote apoptosis in glioma cell. However, the expressions, functions, and mechanisms of action of UBE2R2-AS1 in HCC are still unclear. UBE2R2-AS1 is increased in HCC tissues and cell lines. Increased expression of UBE2R2-AS1 is associated with large tumor size, multiple tumor number, advanced TNM stage, and poor survival of HCC patients. Functional experiments showed that knockdown UBE2R2-AS1 inhibited HCC growth and metastasis through in vitro and in vivo experiments. Regarding the mechanism, UBE2R2-AS1/miR-302b/EGFR established the ceRNA network involved in the modulation of cell progression of HCC cells via activation of PI3K-AKT signaling pathway. Overall, UBE2R2-AS1 may exhibit an oncogenic function in HCC via acting as a sponge for miR-302b to up-regulate EGFR, and may serve as a potential therapeutic target and a prognostic biomarker for HCC patients.

LncRNA SNHG15 predicts poor prognosis in uveal melanoma and its potential pathways

AIM

To evaluate the role of long noncoding RNA (lncRNA) SNHG15 and its potential pathways in uveal melanoma (UM).

METHODS

The SNHG15 mRNA expression level and corresponding clinicopathological characteristics of 80 patients with UM were obtained from the Cancer Genome Atlas (TCGA) database and further analyzed. The SPSS 24.0 statistical software package was used for statistical analyses. To investigate the potential function of SNHG15 in UM, we conducted in-depth research on Gene Set Enrichment Analysis (GSEA).

RESULTS

The univariate analysis revealed that the age, tumor diameter, pathological type, extrascleral extension, cancer status, and high expression of SNHG15 were statistical risk factors for death from all causes. The multivariate analysis suggested that the mRNA expression level of SNHG15 was an independent risk factor for death from all causes, as was age and pathological type. Kaplan-Meier survival analysis confirmed that UM patients with high SNHG15 expression might have a poor prognosis. In addition, SNHG15 was significantly differentially expressed in the different groups of tumor pathologic stage, metastasis and living status. Besides, the logistic regression analysis indicated that high SNHG15 expression group in UM was significantly associated with cancer status, pathologic stage, metastasis, and living status. Moreover, the GSEA indicated the potential pathways regulated by SNHG15 in UM.

CONCLUSION

Our research suggests that SNHG15 may play a vital role as a potential marker in UM that predicts poor prognosis. Besides, GSEA indicates the underlying signaling pathways enriched differentially in SNHG15 high expression phenotype.

Long Non-Coding Small Nucleolar RNA Host Genes (SNHGs) in Endocrine-Related Cancers

Long non-coding RNAs (lncRNAs) are emerging regulators of a diverse range of biological processes through various mechanisms. Genome-wide association studies of tumor samples have identified several lncRNAs, which act as either oncogenes or tumor suppressors in various types of cancers. Small nucleolar RNAs (snoRNAs) are predominantly found in the nucleolus and function as guide RNAs for the processing of transcription. As the host genes of snoRNAs, lncRNA small nucleolar RNA host genes (SNHGs) have been shown to be abnormally expressed in multiple cancers and can participate in cell proliferation, tumor progression, metastasis, and chemoresistance. Here, we review the biological functions and emerging mechanisms of SNHGs involved in the development and progression of endocrine-related cancers including thyroid cancer, breast cancer, pancreatic cancer, ovarian cancer and prostate cancer.

Molecular mechanisms of long non-coding RNAs in anaplastic thyroid cancer: a systematic review

BACKGROUND

anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive cancers. Evidence has shown that the tumorigenesis of ATC is a multistep process involving the accumulation of genetic and epigenetic changes. Several studies have suggested that long non-coding RNAs (lncRNAs) may play an important role in the development and progression of ATC. In this article, we have collected the published reports about the role of lncRNAs in ATC.

METHODS

"Scopus", "Web of Science", "PubMed", "Embase", etc. were systematically searched for articles published since 1990 to 2020 in English language, using the predefined keywords.

RESULTS

961 papers were reviewed and finally 33 papers which fulfilled the inclusion and exclusion criteria were selected. Based on this systematic review, among a lot of evidences on examining the function of lncRNAs in thyroid cancer, there are only a small number of studies about the role of lncRNAs and their molecular mechanisms in the pathogenesis of ATC.

CONCLUSIONS

lncRNAs play a crucial role in regulation of different processes involved in the development and progression of ATC. Currently, just a few lncRNAs have been identified in ATC that may serve as prognosis markers such as GAS5, MIR22HG, and CASC2. Also, because of the dysregulation of Klhl14-AS, HOTAIRM1, and PCA3 during ATC development and progression, they may act as therapeutic targets. However, for most lncRNAs, only a single experiment has evaluated the expression profile in ATC tissues/cells. Therefore, further functional studies and expression profiling is needed to resolve this limitation and identify novel and valid biomarkers.

The Changing Face of in vitro Culture Models for Thyroid Cancer Research: A Systematic Literature Review

Background: Thyroid cancer is the most common endocrine malignancy worldwide. Primary treatment with surgery and radioactive iodine is usually successful, however, there remains a small proportion of thyroid cancers that are resistant to these treatments, and often represent aggressive forms of the disease. Since the 1950s, in vitro thyroid culture systems have been used in thyroid cancer research. In vitro culture models have evolved from 2-dimensional thyrocyte monolayers into physiologically functional 3-dimensional organoids. Recently, research groups have utilized in vitro thyroid cancer models to identify numerous genetic and epigenetic factors that are involved with tumorigenesis as well as test the efficacy of cytotoxic drugs on thyroid cancer cells and identify cancer stem cells within thyroid tumors.

Objective of Review: The objective of this literature review is to summarize how thyroid in vitro culture models have evolved and highlight how in vitro models have been fundamental to thyroid cancer research.

Type of Review: Systematic literature review.

Search Strategy: The National Institute for Health and Care Excellence (NICE) Healthcare and Databases Advanced Search (HDAS) tool was used to search EMBASE, Medline and PubMed databases. The following terms were included in the search: “in vitro” AND “thyroid cancer”. The search period was confined from January 2008 until June 2019. A manual search of the references of review articles and other key articles was also performed using Google Scholar.

Evaluation Method: All experimental studies and review articles that explicitly mentioned the use of in vitro models for thyroid cancer research in the title and/or abstract were considered. Full-text versions of all selected articles were evaluated. Experimental studies were reviewed and grouped according to topic: genetics/epigenetics, drug testing/cancer treatment, and side populations (SP)/tumor microenvironment (TME).

Results: Three thousand three hundred and seventy three articles were identified through database and manual searches. One thousand two hundred and sixteen articles remained after duplicates were removed. Five hundred and eighty nine articles were excluded based on title and/or abstract. Of the remaining 627 full-text articles: 24 were review articles, 332 related to genetic/epigenetics, 240 related to drug testing/treatments, and 31 related to SP/TME.

Conclusion:In vitro cell culture models have been fundamental in thyroid cancer research. There have been many advances in culture techniques- developing complex cellular architecture that more closely resemble tumors in vivo. Genetic and epigenetic factors that have been identified using in vitro culture models can be used as targets for novel drug therapies. In the future, in vitro systems will facilitate personalized medicine, offering bespoke treatments to patients.

High Expression of the Long Noncoding RNA SNHG15 in Cancer Tissue Samples Predicts an Unfavorable Prognosis of Cancer Patients: A Meta-Analysis

Background

Although the prognostic value of lncRNA small nucleolar RNA host gene 15 (SNHG15) expression in cancers has been evaluated in many studies, the results remain controversial. This meta-analysis aimed to clarify the role of SNHG15 in the prognosis of different cancer patients.

Materials and Methods

Eligible studies were selected from PubMed, PMC, EMBASE, Web of Science, and Cochrane Library according to the inclusion and exclusion criteria (up to December 20, 2019). The primary outcome was overall survival (OS) and recurrence-free survival (RFS). The secondary outcome was other clinicopathological parameters (including advanced TNM stage, lymph node metastasis, distant metastases, and gender). The Cancer Genome Atlas (TCGA) dataset was used to verify the analysis results.

Results

Eleven eligible studies were eventually included, involving 9 different types of cancer and 1,079 patients. The high expression of SNHG15 was indicative of a significantly poor OS of cancer patients (HR = 1.96, 95% CI = 1.55–2.47, P < 0.00001). Subgroup analysis showed that the high expression of SNHG15 was associated with a significantly poor OS of patients with digestive cancer (HR = 1.91, 95% CI = 1.38–2.66, P=0.0001), but not lung cancer (HR = 1.83, 95% CI = 0.89–3.76, P=0.010). The RFS of patients with high expression of SNHG15 was shorter than that of patients with low expression of SNHG15 (HR = 2.03, 95% CI = 1.46–2.83, P < 0.00001). In addition, high SNHG15 expression level was significantly correlated with later TNM stage (OR = 3.05, 95% CI = 2.31–4.02, P < 0.00001), lymphatic metastasis (OR = 3.20, 95% CI = 2.30–4.45, P < 0.00001), and distant metastasis (OR = 5.05, 95% CI = 2.15–11.85, P=0.0002). The TCGA verification results were consistent with those observed in our meta-analysis.

Conclusion

High expression of the long noncoding RNA SNHG15 in cancer tissue samples predicts an unfavorable prognosis for cancer patients. LncRNA SNHG15 can be used as an adverse prognostic biomarker for cancer patients.

LncRNA SNHG15: A new budding star in human cancers

OBJECTIVES

Long non-coding RNAs (lncRNAs) represent an important group of non-coding RNAs (ncRNAs) with more than 200 nucleotides in length that are transcribed from the so-called genomic "dark matter." Mounting evidence has shown that lncRNAs have manifested a paramount function in the pathophysiology of human diseases, especially in the pathogenesis and progression of cancers. Despite the exponential growth in lncRNA publications, our understanding of regulatory mechanism of lncRNAs is still limited, and a lot of controversies remain in the current lncRNA knowledge.The purpose of this article is to explore the clinical significance and molecular mechanism of SNHG15 in tumors.

MATERIALS & METHODS

We have systematically searched the Pubmed, Web of Science, Embase and Cochrane databases. We provide an overview of current evidence concerning the functional role, mechanistic models and clinical utilities of SNHG15 in human cancers in this review.

RESULTS

Small nucleolar RNA host gene 15 (SNHG15), a novel lncRNA, is identified as a key regulator in tumorigenesis and progression of various human cancers, including colorectal cancer (CRC), gastric cancer (GC), pancreatic cancer (PC) and hepatocellular carcinoma (HCC). Dysregulation of SNHG15 has been revealed to be dramatically correlated with advanced clinicopathological factors and predicts poor prognosis, suggesting its potential clinical value as a promising biomarker and therapeutic target for cancer patients.

CONCLUSIONS

LncRNA SNHG15 may serve as a prospective and novel biomarker for molecular diagnosis and therapeutics in patients with cancer.

LncRNA ASB16-AS1 Promotes Growth And Invasion Of Hepatocellular Carcinoma Through Regulating miR-1827/FZD4 Axis And Activating Wnt/β-Catenin Pathway

Background

To date, although several long noncoding RNAs (lncRNAs) are reported to regulate hepatocellular carcinoma (HCC) development, their relationship still remains elusive. ASB16-AS1 is a poorly researched novel lncRNA. We aimed to investigate its function in HCC progression.

Methods

qRT-PCR and in situ hybridization (ISH) were used to analyze ASB16-AS1 expression in HCC tissues. CCK8, Edu incorporation and colony formation were used to determine cell proliferation. Transwell assay was used to examine migration and invasion. Luciferase reporter assay was used to analyze the interactions among ASB16-AS1, miR-1827 and FZD4.

Results

Bioinformatics analysis identified ASB16-AS1 was overexpressed in HCC tissues, which was further validated by qRT-PCR and in situ hybridization (ISH). Besides, ASB16-AS1 was demonstrated to be a potential indicator for HCC prognosis. Functional studies showed ASB16-AS1 knockdown attenuated proliferation, migration and invasion of HCC cells. Mechanistically, ASB16-AS1 directly interacted with miR-1827 and promoted FZD4 expression by sponging miR-1827. Overexpressed FZD4 eventually activated Wnt/β-catenin pathway and contributed to HCC progression.

Conclusion

Our work is the first to identify ASB16-AS1 as an oncogene that enhances HCC progression by modulating miR-1827/FZD4/Wnt/β-catenin pathways.

lncRNA-SNHG15 accelerates the development of hepatocellular carcinoma by targeting miR-490-3p/ histone deacetylase 2 axis

BACKGROUND

Hepatocellular carcinoma (HCC) has become a great threat for people’s health. Many long noncoding RNAs are involved in the pathogenesis of HCC. SNHG15, as a tissue specific long noncoding RNAs, has been studied in many human cancers, except HCC.

AIM

To explore the regulatory mechanism of SNHG15 in HCC.

METHODS

In the present research, 101 HCC patient samples, two HCC cell lines and one normal liver cell line were used. RT-qPCR and Western blot analysis were applied to detect SNHG15, miR-490-3p and histone deacetylase 2 (HDAC2) expression. The regulatory mechanism of SNHG15 was investigated using CCK-8, Transwell and luciferase reporter assays.

RESULTS

Our research showed that up-regulation of SNHG15 was found in HCC and was related to aggressive behaviors in HCC patients. Moreover, knockdown of SNHG15 restrained HCC cell proliferation, migration and invasion. In addition, SNHG15 served as a molecular sponge for miR-490-3p. Further, miR-490-3p directly targets HDAC2. HDAC2 was involved in HCC progression by interacting with the SNHG15/miR-490-3p axis.

CONCLUSION

In conclusion, long noncoding RNA SNHG15 promotes HCC progression by mediating the miR-490-3p/HDAC2 axis in HCC.

Long noncoding RNA ABHD11-AS1 functions as a competing endogenous RNA to regulate papillary thyroid cancer progression by miR-199a-5p/SLC1A5 axis

With the increasing incidence of papillary thyroid cancer (PTC), more attention has been paid to exploring the mechanism of PTC initiation and progression. In addition, ectopic expression of long noncoding RNAs (lncRNAs) is reported to play a pivotal role in multiple human cancers. Based on these findings, we examined lncRNA ABHD11 antisense RNA 1 (ABHD11-AS1) expression and its clinical significance, biological function and mechanism in PTC. First, we analyzed thyroid ABHD11-AS1 expression in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Then, qRT-PCR was applied to detect the expression in paired PTC tissues and adjacent normal tissues, as well as in PTC cell lines (TPC-1 and K-1) and a normal thyroid follicular epithelium cell line (Nthy-ori3-1). In addition, we validated the relationship between ABHD11-AS1 expression and clinicopathological features by the Pearson X² test. The oncogenic role of ABHD11-AS1 and its regulation of miR-199a-5p in PTC were examined by biological assays. Finally, bioinformatics analysis and mechanism assays were used to elucidate the underlying mechanism. We found that ABHD11-AS1 was remarkably overexpressed in PTC, and high expression was related to tumor size, lymph node metastasis, extrathyroidal extension and advanced TNM stage. Moreover, ABHD11-AS1 enhanced the abilities of cell proliferation, migration, and invasion, inhibited apoptosis in vitro, promoted tumorigenesis in vivo via sponging miR-199a-5p and then induced SLC1A5 activation. In addition, rescue assays were performed to confirm the ABHD11-AS1/miR-199a-5p/SLC1A5 axis. Taken together, the data show that ABHD11-AS1 acts as a competing endogenous RNA (ceRNA) to exert malignant properties in PTC through the miR-199a-5p/SLC1A5 axis. Therefore, our study may shed light on PTC diagnosis and therapies.

Long non-coding RNA MIAT promotes papillary thyroid cancer progression through upregulating LASP1

Background

Accumulating evidences indicate that long non-coding RNAs (lncRNAs) play an important role in initiation and development of thyroid cancer. However, the underlying molecular mechanism remains elusive.

Methods

To explore potential oncogenic and tumor suppressive lncRNAs in papillary thyroid cancer (PTC), we performed RNA sequencing to discover differentially expression lncRNAs between PTC tissues and matched normal tissues. RT-qPCR was used to validate differentially expressed lncRNAs. Bioinformatic analysis was performed to predicted potential miRNA and gene which might be regulated by MIAT. Cell proliferation, invasion and cycle assay were conducted to study the function of MIAT and LASP1 in PTC.

Results

Through analysis of RNA sequencing, we observed that lncRNA-MIAT was overexpressed in PTC tissues. The upregulation of MIAT was further confirmed in 40 pairs of PTC tissues and normal tissues we collected. In the function assays, results suggested that MIAT silencing led to inhibition of cell proliferation, invasion and disruption of cell cycle progression in PTC cells. Mechanistically, MIAT directly bound to miR-324-3p and upregulated LASP1 expression in PTC cells. In addition, expression of MIAT was positively correlated with LASP1 mRNA expression in samples collected from patients with PTC. More importantly, transfection of recombinant LASP1 attenuated MIAT silencing induced inhibition of cell proliferation, invasion and disruption of cell cycle progression in PTC cells.

Conclusions

In conclusion, the findings suggest that lncRNA-MIAT may promote PTC proliferation and invasion through physically binding miR-324-3p and upregulation of LASP1.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0913-z) contains supplementary material, which is available to authorized users.

SNHG15: a promising cancer-related long noncoding RNA

Cancer is expected to rank as the leading cause of death worldwide due to increasing morbidity and mortality. Long noncoding RNAs (lncRNAs) have been found to play pivotal roles in multiple biological processes, such as transcriptional interference, posttranscriptional regulation and epigenetic modification. Small nucleolar RNA host gene 15 (SNHG15), a snoRNA host gene which produces a short half-lived lncRNA, was reported to be upregulated in tumor cells and participate in the occurrence and development of multiple cancers. And more than half of the SNHG15 research in cancers has been published within the last 2 years. In this review, we summarized the current evidence concerning the biological functions and molecular mechanisms of SNHG15 in various cancers, including gastric, hepatocellular, pancreatic, colorectal, breast, and thyroid cancer, osteosarcoma, glioma, lung cancer, renal cell carcinoma, and epithelial ovarian cancer. SNHG15 plays critical roles in regulation of cell proliferation, migration and invasion of tumors via different potential mechanisms. Moreover, the abnormal expression of SNHG15 was associated with clinical features of patients with cancers. Consequently, SNHG15 could be considered as a promising biomarker for cancer diagnosis, prognosis or treatment.