LncRNA-SNHG16 predicts poor prognosis and promotes tumor proliferation through epigenetically silencing p21 in bladder cancer

The biological role of lncRNAs in the acute lymphocytic leukemia: An updated review

The cause of leukemia, a common malignancy of the hematological system, is unknown. The structure of long non-coding RNAs (lncRNAs) is similar to mRNA but no ability to encode proteins. Numerous malignancies, including different forms of leukemia, are linked to Lnc-RNAs. It is verified that the carcinogenesis and growth of a variety of human malignancies are significantly influenced by aberrant lncRNA expression. The body of evidence linking various types of lncRNAs to the etiology of leukemia has dramatically increased during the past ten years. Some lncRNAs are therefore anticipated to function as novel therapeutic targets, diagnostic biomarkers, and clinical outcome predictions. Additionally, these lncRNAs may provide new therapeutic options and insight into the pathophysiology of diseases, particularly leukemia. Thus, this review outlines the present comprehension of leukemia-associated lncRNAs.

The value of urinary exosomal lncRNA SNHG16 as a diagnostic biomarker for bladder cancer

OBJECTIVE

To detect the expression level of urinary exosomal lncRNA SNHG16 in patients with bladder cancer and healthy individuals and explore its clinical application value in the diagnosis of bladder cancer.

METHODS

Urine samples were collected from 42 patients with bladder cancer and 42 healthy volunteers who visited Lu'an Hospital of Anhui Medical University and the Second Hospital of Tianjin Medical University from January 2020 to December 2022. The expression levels of lncRNA SNHG16 in urinary exosomes of the two groups were detected by RT‒qPCR, and their correlation with clinical pathological parameters of bladder cancer patients was analysed. An Receiver Operating Characteristic(ROC) curve was drawn to analyse the diagnostic value of urinary exosomal lncRNA SNHG16 for bladder cancer and compared with urinary cytology.

RESULTS

The expression of urinary exosomal lncRNA SNHG16 in patients with bladder cancer was significantly higher (P < 0.05), and the expression level had no correlation with the age, sex, pathological T stage, pathological grade, or tumour size of bladder cancer patients (P > 0.05). The Area Under Curve(AUC) of urinary exosomal lncRNA SNHG16 in diagnosing bladder cancer was 0.791, which was superior to that of urinary cytology (AUC = 0.597).

CONCLUSION

Urinary exosomal lncRNA SNHG16 with high expression can serve as a potential diagnostic biological marker for bladder cancer.

Molecular landscape of LncRNAs in bladder cancer: From drug resistance to novel LncRNA-based therapeutic strategies

Bladder cancer (BC) is a common and serious type of cancer that ranks among the top ten most prevalent malignancies worldwide. Due to the high occurrence rate of BC, the aggressive nature of cancer cells, and their resistance to medication, managing this disease has become a growing challenge in clinical care. Long noncoding RNAs (lncRNAs) are a group of RNA transcripts that do not code for proteins and are more than 200 nucleotides in length. They play a significant role in controlling cellular pathways and molecular interactions during the onset, development and progression of different types of cancers. Recent advancements in high-throughput gene sequencing technology have led to the identification of various differentially expressed lncRNAs in BC, which indicate abnormal expression. In this review, we summarize that these lncRNAs have been found to impact several functions related to the development of BC, including proliferation, cell growth, migration, metastasis, apoptosis, epithelial-mesenchymal transition, and chemo- and radio-resistance. Additionally, lncRNAs may improve prognosis prediction for BC patients, indicating a future use for them as prognostic and diagnostic biomarkers for BC patients. This review highlights that genetic tools and anti-tumor agents, such as CRISPR/Cas systems, siRNA, shRNA, antisense oligonucleotides, and vectors, have been created for use in preclinical cancer models. This has led to a growing interest in using lncRNAs based on positive research findings.

Epigenetic and Immunological Features of Bladder Cancer

Bladder cancer (BLCA) is one of the most common types of malignant tumors of the urogenital system in adults. Globally, the incidence of BLCA is more than 500,000 new cases worldwide annually, and every year, the number of registered cases of BLCA increases noticeably. Currently, the diagnosis of BLCA is based on cystoscopy and cytological examination of urine and additional laboratory and instrumental studies. However, cystoscopy is an invasive study, and voided urine cytology has a low level of sensitivity, so there is a clear need to develop more reliable markers and test systems for detecting the disease with high sensitivity and specificity. Human body fluids (urine, serum, and plasma) are known to contain significant amounts of tumorigenic nucleic acids, circulating immune cells and proinflammatory mediators that can serve as noninvasive biomarkers, particularly useful for early cancer detection, follow-up of patients, and personalization of their treatment. The review describes the most significant advances in epigenetics of BLCA.

In vitro Anti-malignant Property of PCMT1 Silencing and Identification of the SNHG16/miR-195/PCMT1 Regulatory Axis in Breast Cancer Cells

BACKGROUND

Protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) is a highly conserved protein repair enzyme that participates in regulating the progression of human cancers. We therefore studied the function and the related mechanisms of PCMT1 in breast cancer cells.

METHODS

Expression profile and prognostic analysis of PCMT1 in breast cancer patients were analyzed using online databases. PCMT1 expression in breast cancer cells was detected by western blot analysis. Cell proliferation was determined by CCK-8 and colony formation assays. Apoptosis was evaluated using flow cytometry analysis and caspase-3/7 activity assay. Cell invasion was assessed by Transwell invasion assay. The small nucleolar RNA host gene 16 (SNHG16)/miR-195/PCMT1 regulatory axis was identified using bioinformatics analysis.

RESULTS

PCMT1 expression was increased in breast cancer tissues and cells. High PCMT1 expression was correlated with poor prognosis in breast cancer patients. PCMT1 knockdown suppressed cell proliferation and colony formation ability in breast cancer cells. Moreover, PCMT1 knockdown induced apoptosis and restrained the invasive ability in breast cancer cells. PCMT1 overexpression increased the proliferative and invasive abilities of breast cancer cells. miR-195 was identified as the unique upstream miRNA of PCMT1. SNHG16 was identified as the unique upstream lncRNA of miR-195. SNHG16 knockdown downregulated PCMT1 by increasing miR-195 expression. Breast cancer cell proliferation was regulated by the SNHG16/miR-195/PCMT1 axis.

CONCLUSION

PCMT1 silencing inhibited cell proliferation and invasion and induced apoptosis in breast cancer cells and the SNHG16/miR-195/PCMT1 regulatory axis might serve as a potential therapeutic target for breast cancer.

SNHG18 inhibits bladder cancer cell proliferation by increasing p21 transcription through destabilizing c-Myc protein

BACKGROUND

Long non-coding RNAs (lncRNAs) have been confirmed to play important roles in various cancers including bladder cancer (BC). The precise expression pattern of lncRNA small nucleolar RNA host gene 18 (SNHG18) in BC and its mechanisms of action have not been fully explored.

MATERIALS AND METHODS

The expression of SNHG18 was evaluated by RT-qPCR in bladder cancer clinical samples and human bladder cancer cell lines, and stable cell lines overexpressing SNHG18 were constructed. The effect of SNHG18 on the proliferation of bladder cancer cells was detected by soft agar colony formation test, ATP activity test and subcutaneous tumorigenesis model in nude mice. The specific mechanism of SNHG18 inhibition of bladder cancer proliferation was studied by flow cytometry, western blotting, dual luciferase reporter gene assay and protein degradation assay.

RESULTS

We found that SNHG18 is significantly downregulated in BC tissues and cell lines. Kaplan-Meier analysis showed that SNHG18 expression is positively correlated with survival in BC patients. Ectopic overexpression of SNHG18 significantly inhibited the proliferation of BC cells in vitro and in vivo. Further mechanistic investigations demonstrated that SNHG18 inhibited c-Myc expression by modulating the ubiquitination-proteasome pathway and that c-Myc is the critical transcription factor that mediates SNHG18 inhibition of BC growth by directly binding to the p21 promoter, which was attributed with significant p21 accumulation.

CONCLUSIONS

SNHG18 promotes the transcription and expression of p21 by inhibiting c-Myc expression, leading to G0-G1 arrest and inhibiting the proliferation of bladder cancer cells. These findings highlight a novel cell cycle regulatory mechanism involving the SNHG18/c-Myc/p21 pathway in BC pathogenesis and could potentially lead to new lncRNA-based diagnostics and/or therapeutics for BC.

Upregulation of OTX2-AS1 is Associated With Immune Infiltration and Predicts Prognosis of Gastric Cancer

BACKGROUND

It is unclear whether the long non-coding RNA (lncRNA) OTX2 antisense RNA 1 (OTX2-AS1) plays a pivotal role in gastric cancer (GC). An analysis of The Cancer Genome Atlas (TCGA) database data and bioinformatics was used to explore the relationship between OTX2-AS1 and GC in the current study.

METHODS

We evaluated the relationship between clinical features and OTX2-AS1 expression, prognostic factors, and the significant involvement of OTX2-AS1 in function using various statistical methods, such as Kaplan-Meier method, Cox regression analysis, Gene Set Enrichment Analysis (GSEA), and immune infiltration analysis. GC cell lines were tested for OTX2-AS1 expression using qRT-PCR.

RESULTS

A high level of OTX2-AS1 expression was significantly and negatively associated with Helicobacter pylori (H pylori) infection in GC patients (P = .006) and predicted a poorer overall survival (OS) (HR: 1.54; 95% CI: 1.10-2.14; P = .011), progression-free interval (PFI) (HR: 1.75; 95% CI: 1.22-2.51; P = .002) and disease-specific survival (DSS) (HR: 1.85; 95% CI: 1.21-2.85; P = .005) in GC patients. There was an independent correlation between OTX2-AS1 expression (HR: 1.771; 95% CI: 1.164-2.696; P = .008) and OS in patients with GC. There were differential enrichments for the OTX2-AS1 high expression phenotype in the olfactory transduction, G alpha (s) signaling events, keratinization, olfactory signaling pathway, and preimplantation embryo. OTX2-AS1 expression may be related to certain immune-infiltrating cells. Compared to gastric epithelial cells (GES-1), GC cell lines showed a significant increase in OTX2-AS1 expression.

CONCLUSION

There was a significant association between OTX2-AS1 expression in GC patients and poor survival, suggesting that it may be a useful biomarker for prognosis and immunotherapy outcome of stomach adenocarcinoma (STAD) in GC.

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.

Cuproptosis-Related lncRNAs are Biomarkers of Prognosis and Immune Microenvironment in Head and Neck Squamous Cell Carcinoma

Background: Cuproptosis is a new type of cell death that induces protein toxic stress and eventually leads to cell death. Hence, regulating cuproptosis in tumor cells is a new therapeutic approach. However, studies on cuproptosis-related long noncoding RNA (lncRNA) in head and neck squamous cell carcinoma (HNSC) have not been found. This study aimed to explore the cuproptosis-related lncRNAs prognostic marker and their relationship to immune microenvironment in HNSC by using bioinformatics methods.

Methods: RNA sequencing, genomic mutations, and clinical data of TCGA_HNSC were downloaded from The Cancer Genome Atlas. HNSC patients were randomly assigned to either a training group or a validation cohort. The least absolute shrinkage and selection operator Cox regression and multivariate Cox regression models were used to determine the prognostic model in the training cohort, and its independent prognostic effect was further confirmed in the validation and entire cohorts.

Results: Based on previous literature, we collected 19 genes associated with cuproptosis. Afterward, 783 cuproptosis-related lncRNAs were obtained through coexpression. Cox model revealed and constructed eight cuproptosis-related lncRNAs prognostic marker (AL132800.1, AC090587.1, AC079160.1, AC011462.4, AL157888.1, GRHL3-AS1, SNHG16, and AC021148.2). Patients were divided into high- and low-risk groups based on the median risk score. The Kaplan–Meier survival curve revealed that the overall survival between the high- and low-risk groups was statistically significant. The receiver operating characteristic curve and principal component analysis demonstrated the accurate prognostic ability of the model. Univariate and multivariate Cox regression analysis showed that risk score was an independent prognostic factor. In addition, we used multivariate Cox regression to establish a nomogram of the predictive power of prognostic markers. The tumor mutation burden showed significant differences between the high- and low-risk groups. HNSC patients in the high-risk group responded better to immunotherapy than those in the low-risk group. We also found that risk scores were significantly associated with drug sensitivity in HNSC.

Conclusion: In summary, our study identified eight cuprotosis-related lncRNAs signature of HNSC as the prognostic predictor, which may be promising biomarkers for predicting the benefit of HNSC immunotherapy as well as drug sensitivity.

Circulating lncRNA- and miRNA-Associated ceRNA Network as a Potential Prognostic Biomarker for Non-Hodgkin Lymphoma: A Bioinformatics Analysis and a Pilot Study

Non-Hodgkin lymphoma (NHL) is characterized by a great variability in patient outcomes, resulting in the critical need for identifying new molecular prognostic biomarkers. This study aimed to identify novel circulating prognostic biomarkers based on an miRNA/lncRNA-associated ceRNA network for NHL. Using bioinformatic analysis, we identified the miRNA-lncRNA pairs, and using RT-qPCR, we analyzed their plasma levels in a cohort of 113 NHL patients to assess their prognostic value. Bioinformatic analysis identified SNHG16 and SNHG6 as hsa-miR-20a-5p and hsa-miR-181a-5p sponges, respectively. Plasma levels of hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNG6 were significantly associated with more aggressive disease and IPI/FLIPI scores. Moreover, we found that patients with risk expression profiles of hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNHG6 presented a higher risk of positive bone marrow involvement. Moreover, hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNHG6 pairs’ plasma levels were associated with overall survival and progression-free survival of NHL patients, being independent prognostic factors in a multivariate Cox analysis. The prediction models incorporating the ceRNA network expression analysis improved the predictive capacity compared to the model, which only considered the clinicopathological variables. There are still few studies on using the ceRNA network as a potential prognostic biomarker, particularly in NHL, which may permit the implementation of a more personalized management of these patients.

Long Noncoding RNA SNHG16 Regulates the Growth of Human Lung Cancer Cells by Modulating the Expression of Aldehyde Dehydrogenase 2 (ALDH2)

The involvement of long noncoding RNA (lncRNA) SNHG16 has been reported in several human cancers. Notwithstanding, the role of lncRNA SNHG16 is yet largely unknown in human lung cancer. Consequently, this study was undertaken to investigate the role and therapeutic potential of SNHG16 in human lung cancer. The results showed a significant (P < 0.05) transcriptional upregulation of SNHG16 in lung cancer tissues and cell lines. However, downregulation of SNHG16 resulted in significant (P < 0.05) inhibition of lung cancer A549 and SK-LU-1 cell proliferation. DAPI and annexin V/PI assays revealed apoptosis to be responsible for inhibition of cell proliferation and colony formation observed upon SNHG16 knockdown. This was accompanied by enhancement of Bax and suppression of Bcl-2 expression in A549 and SK-LU-1 cells. Transwell assays revealed that silencing of SNHG16 also significantly (P < 0.05) inhibited migration and invasion of A549 and SK-LU-1 cells. Bioinformatic analysis revealed that SNHG16 interacted with ALDH2 to exert its effects in human lung cancer cells. The expression of ALDH2 was found to be significantly (P < 0.05) suppressed in human lung cancer tissues and cell lines. Overexpression of ALDH2 inhibited the proliferation and colony formation of the A549 and SK-LU-1 cells. However, silencing of ALDH2 could avoid the tumor-suppressive effects of SNHG16 knockdown. Finally, SNHG16 silencing was also found to inhibit in vivo tumor growth. Collectively, the study unveils the molecular role of SNHG16 in regulating the development of lung cancer by interacting with ALDH2.

Fibroblast Activation Protein-Alpha is a Prognostic Biomarker Associated With Ferroptosis in Stomach Adenocarcinoma

Background: The potential role of fibroblast activation protein-alpha (FAP) in modulating the progression and invasion of stomach adenocarcinoma (STAD) has not yet been comprehensively investigated. This study aimed to explore the role of FAP in STAD and the underlying association between FAP and the tumor microenvironment (TME) and ferroptosis.

Methods: Overall survival was analyzed to evaluate the prognostic value of FAP based on gene expression data and clinical information on STAD. Associations between FAP expression, clinical parameters, and immune characteristics were comprehensively analyzed. The ferroptosis-related patterns of STAD samples were investigated based on 43 ferroptosis-related genes, and the correlations between these clusters and clinical characteristics were evaluated. The possible biological functions and pathways were explored using gene set enrichment analysis (GSEA).

Results: FAP was identified as a novel biomarker that significantly contributed to the poor prognosis of STAD (hazard ratio = 1.270, P = 0.013). The elevated level of FAP expression was related to a more advanced tumor stage in STAD. The close relationship between FAP and the TME was validated. Four distinct ferroptosis-related clusters (A–D) were evident. Evaluating ferroptosis-related clusters could illustrate the stages of STAD and patient prognosis. Cluster C displayed the lowest FAP expression and a better prognosis than the other clusters. The different clusters were linked to different biological mechanisms, including epithelial-mesenchymal transition and immune-relevant pathways.

Conclusion: FAP is a promising biomarker to distinguish prognosis and is associated with the TME and ferroptosis in STAD.

ABHD11-AS1: An Emerging Long Non-Coding RNA (lncRNA) with Clinical Significance in Human Malignancies

The aberrant expression of lncRNAs has been linked to the development and progression of different cancers. One such lncRNA is ABHD11 antisense RNA 1 (ABHD11-AS1), which has recently gained attention for its significant role in human malignancies. ABHD11-AS1 is highly expressed in gastric, lung, breast, colorectal, thyroid, pancreas, ovary, endometrium, cervix, and bladder cancers. Several reports highlighted the clinical significance of ABHD11-AS1 in prognosis, diagnosis, prediction of cancer progression stage, and treatment response. Significantly, the levels of ABHD11-AS1 in gastric juice had been exhibited as a clinical biomarker for the assessment of gastric cancer, while its serum levels have prognostic potential in thyroid cancers. The ABHD11-AS1 has been reported to exert oncogenic effects by sponging different microRNAs (miRNAs), altering signaling pathways such as PI3K/Akt, epigenetic mechanisms, and N6-methyladenosine (m⁶A) RNA modification. In contrast, the mouse homolog of AHD11-AS1 (Abhd11os) overexpression had exhibited neuroprotective effects against mutant huntingtin-induced toxicity. Considering the emerging research reports, the authors attempted in this first review on ABHD11-AS1 to summarize and highlight its oncogenic potential and clinical significance in different human cancers. Lastly, we underlined the necessity for future mechanistic studies to unravel the role of ABHD11-AS1 in tumor development, prognosis, progression, and targeted therapeutic approaches.

Long intergenic non-protein coding RNA 662 accelerates the progression of gastric cancer through up-regulating centrosomal protein 55 by sponging microRNA-195-5p

Long non-coding RNAs (lncRNAs) are important players in regulating diverse human diseases, including cancers. Nonetheless, the function of long intergenic non-protein coding RNA 662 (LINC00662) in gastric cancer (GC) carcinogenesis and progression remains to be delineated. In the present study, LINC00662, microRNA-195-5p (miR-195-5p) and centrosomal protein 55 (CEP55) mRNA expression levels were quantified by qRT-PCR. GC cell proliferation, migration and invasion were analyzed by CCK-8, BrdU and Transwell assays. Besides, dual-luciferase reporter and RNA pull-down assays were conducted for verifying the targeting relationships of LINC00662, miR-195-5p and CEP55. The regulatory functions of LINC00662 and miR-195-5p on CEP55 were examined utilizing Western blot. In this study, it was revealed that LINC00662 expression level was elevated in GC tissues and cells. LINC00662 overexpression facilitated the malignant biological behaviors of GC cells whereas knockdown of LINC00662 worked oppositely. In terms of mechanism, LINC00662 targeted miR-195-5p to modulate CEP55 expression. In conclusion, LINC00662 facilitates the malignant biological behaviors of GC cells via miR-195-5p/CEP55 axis, and therefore, it may be a promising target for GC treatment.

A Review on the Role of Small Nucleolar RNA Host Gene 6 Long Non-coding RNAs in the Carcinogenic Processes

Being located on 17q25.1, small nucleolar RNA host gene 6 (SNHG16) is a member of SNHG family of long non-coding RNAs (lncRNA) with 4 exons and 13 splice variants. This lncRNA serves as a sponge for a variety of miRNAs, namely miR-520a-3p, miR-4500, miR-146a miR-16–5p, miR-98, let-7a-5p, hsa-miR-93, miR-17-5p, miR-186, miR-302a-3p, miR-605-3p, miR-140-5p, miR-195, let-7b-5p, miR-16, miR-340, miR-1301, miR-205, miR-488, miR-1285-3p, miR-146a-5p, and miR-124-3p. This lncRNA can affect activity of TGF-β1/SMAD5, mTOR, NF-κB, Wnt, RAS/RAF/MEK/ERK and PI3K/AKT pathways. Almost all studies have reported oncogenic effect of SNHG16 in diverse cell types. Here, we explain the results of studies about the oncogenic role of SNHG16 according to three distinct sets of evidence, i.e., in vitro, animal, and clinical evidence.

Biological functions and clinical significance of long noncoding RNAs in bladder cancer

Bladder cancer (BCa) is one of the 10 most common cancers with high morbidity and mortality worldwide. Long noncoding RNAs (lncRNAs), a large class of noncoding RNA transcripts, consist of more than 200 nucleotides and play a significant role in the regulation of molecular interactions and cellular pathways during the occurrence and development of various cancers. In recent years, with the rapid advancement of high-throughput gene sequencing technology, several differentially expressed lncRNAs have been discovered in BCa, and their functions have been proven to have an impact on BCa development, such as cell growth and proliferation, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and drug-resistance. Furthermore, evidence suggests that lncRNAs are significantly associated with BCa patients' clinicopathological characteristics, especially tumor grade, TNM stage, and clinical progression stage. In addition, lncRNAs have the potential to more accurately predict BCa patient prognosis, suggesting their potential as diagnostic and prognostic biomarkers for BCa patients in the future. In this review, we briefly summarize and discuss recent research progress on BCa-associated lncRNAs, while focusing on their biological functions and mechanisms, clinical significance, and targeted therapy in BCa oncogenesis and malignant progression.

Joint changes in RNA, RNA polymerase II, and promoter activity through the cell cycle identify non-coding RNAs involved in proliferation

Proper regulation of the cell cycle is necessary for normal growth and development of all organisms. Conversely, altered cell cycle regulation often underlies proliferative diseases such as cancer. Long non-coding RNAs (lncRNAs) are recognized as important regulators of gene expression and are often found dysregulated in diseases, including cancers. However, identifying lncRNAs with cell cycle functions is challenging due to their often low and cell-type specific expression. We present a highly effective method that analyses changes in promoter activity, transcription, and RNA levels for identifying genes enriched for cell cycle functions. Specifically, by combining RNA sequencing with ChIP sequencing through the cell cycle of synchronized human keratinocytes, we identified 1009 genes with cell cycle-dependent expression and correlated changes in RNA polymerase II occupancy or promoter activity as measured by histone 3 lysine 4 trimethylation (H3K4me3). These genes were highly enriched for genes with known cell cycle functions and included 57 lncRNAs. We selected four of these lncRNAs-SNHG26, EMSLR, ZFAS1, and EPB41L4A-AS1-for further experimental validation and found that knockdown of each of the four lncRNAs affected cell cycle phase distributions and reduced proliferation in multiple cell lines. These results show that many genes with cell cycle functions have concomitant cell-cycle dependent changes in promoter activity, transcription, and RNA levels and support that our multi-omics method is well suited for identifying lncRNAs involved in the cell cycle.

LncRNA SNHG16 promotes Schwann cell proliferation and migration to repair sciatic nerve injury

Background

To investigate the expression of long non-coding RNA (lncRNA) Snorna hostgene16 (SNHG16) in sciatic nerve injury tissues and cells. The molecular mechanism of SNHG16 regulating signal activator of transcription 3 (STAT3) expression through “sponge” adsorption of miR-93-5p was also studied.

Methods

A rat model of sciatic nerve injury was established, and primary Schwann cells (SCs) were extracted. The expression of SNHG16 in animal tissues with sciatic nerve injury and SCs treated with ischemia and hypoxia was detected by qPCR, and CCK-8 assay, cell scratch assay, and Transwell chamber assay were used to detect cell proliferation, migration, and invasion. The targeted binding of SNHG16 to miR-93-5p was verified by double luciferase reporter gene assay and miRNA immunoprecipitation assay. MiR-93-5p mimic, SNHG16 overexpression vector, and sh-STAT3 plasmid were transfected into cells, respectively, and the mRNA expressions of SNHG16, miR-93-5p, and STAT3 in the cells were detected by qPCR.

Results

The expression of lncRNA SNHG16 was decreased after sciatic nerve injury, while overexpression of SNHG16 promoted the proliferation, migration, and invasion of SCs. The results of dual luciferase reporter gene assay and miRNA immunoprecipitation reaction showed miR-93-5p interacted with SNHG16, and the overexpression of miR-93-5p reversed the promoting effects of SNHG16 on the proliferation and invasion of SCs. At the same time, the knockdown of STAT3, which is the target gene of miR-93-5p, reversed the proliferation and invasion promotion effect of SNHG16 on SCs. SNHG16 affected the expression of its downstream target gene STAT3 by adsorbing miR-93-5p via endogenous competitive sponge.

Conclusions

SNHG16 can regulate STAT3 expression by sponge adsorption of miR-93-5p in SCs, and SNHG16 and miR-93-5p can be used as potential targets for the diagnosis and treatment of sciatic nerve injury.

Inhibition of MIR4435-2HG on Invasion, Migration, and EMT of Gastric Carcinoma Cells by Mediating MiR-138-5p/Sox4 Axis

Background

The previous investigations have identified that long non-coding RNA (lncRNAs) act as crucial regulators in gastric carcinoma. However, the function of lncRNA MIR4435-2HG in the modulation of gastric carcinoma remains elusive. Here, we aimed to explore the role of MIR4435-2HG in gastric carcinoma.

Method

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were applied to select the differently expressed lncRNAs in gastric carcinoma. The qRT-PCR was applied to analyze MIR4435-2HG expression in carcinoma tissues and cell lines. The effect of MIR4435-2HG on proliferation, invasion, migration, and apoptosis of gastric carcinoma cells was detected by Cell Counting Kit-8 (CCK-8) assays, transwell assays, and flow cytometry in vitro. A subcutaneous tumor model was constructed to examine the tumor growth of gastric carcinoma cells after knocking out MIR4435-2HG. RNA immunoprecipitation and luciferase reporting assays were applied to evaluate the interaction of MIR4435-2HG, miR-138-5p, and Sox4.

Results

The bioinformatics analysis based on TCGA and GEO databases indicated that MIR4435-2HG was obviously elevated in gastric carcinoma samples. The qRT-PCR analysis revealed that MIR4435-2HG was upregulated in clinical gastric carcinoma tissues and cells. The high expression of MIR4435-2HG is associated with the poor survival rate of patients. The knockout of MIR4435-2HG could repress the proliferation, invasion, migration, and epithelial–mesenchymal transition (EMT) and accelerate the apoptosis of gastric carcinoma cells. Moreover, the deletion of MIR4435-2HG was able to attenuate the tumor growth in vivo. Mechanically, we identified that MIR4435-2HG enhanced Sox4 expression by directly interacting with miR-138-5p as a competitive endogenous RNA (ceRNA) in gastric carcinoma cells, in which Sox4 was targeted by miR-138-5p.

Conclusion

MIR4435-2HG is elevated in gastric carcinoma cells and contributes to the growth, metastasis, and EMT of gastric carcinoma cells by targeting miR-138-5p/Sox4 axis. MIR4435-2HG may be applied as a potential therapeutic target in gastric carcinoma.

Long non-coding RNAs as new players in bladder cancer: Lessons from pre-clinical and clinical studies

The clinical management of bladder cancer (BC) has become an increasing challenge due to high incidence rate of BC, malignant behavior of cancer cells and drug resistance. The non-coding RNAs are considered as key factors involved in BC progression. The long non-coding RNAs (lncRNAs) are RNA molecules and do not encode proteins. They have more than 200 nucleotides in length and affect gene expression at epigenetic, transcriptional and post-transcriptional phases. The lncRNAs demonstrate abnormal expression in BC cells and tissues. The present aims to identifying lncRNAs with tumor-suppressor and tumor-promoting roles, and evaluating their roles as regulatory of growth and migration. Apoptosis, glycolysis and EMT are tightly regulated by lncRNAs in BC. Response of BC cells to cisplatin, doxorubicin and gemcitabine chemotherapy is modulated by lncRNAs. LncRNAs regulate immune cell infiltration in tumor microenvironment and affect response of BC cells to immunotherapy. Besides, lncRNAs are able to regulate microRNAs, STAT3, Wnt, PTEN and PI3K/Akt pathways in affecting both proliferation and migration of BC cells. Noteworthy, anti-tumor compounds and genetic tools such as siRNA, shRNA and CRISPR/Cas systems can regulate lncRNA expression in BC. Finally, lncRNAs and exosomal lncRNAs can be considered as potential diagnostic and prognostic tools in BC.

Muscone suppresses gastric cancer via regulation of miRNA-145

This study aims to determine the effects and mechanism of action of muscone on the biological activity of the gastric cancer cell lines SGC-7901 and MGC-803 (proliferation, apoptosis, invasion, and migration) in vitro. An optimal muscone concentration was determined using MTT and cell apoptosis tests. The SGC-7901 and MGC-803 cells were divided into five groups: normal control, muscone, miRNA, muscone + miRNA, and muscone + miRNA inhibitor. Cell proliferation rate, apoptosis rate, cell cycle phase distribution, number of invading cells, and wound healing rate were compared among the five groups using MTT, flow cytometry, transwell, and wound healing assays. Relative expression levels of the proteins PI3K, AKT, P21, c-Myc, MMP-2, and MMP-9 were measured by Western blot. Compared with the control group, the groups treated with muscone and miRNA showed significantly lower cell proliferation rate, number of invading cells, and wound healing rate (p < .05 for all), but significantly higher rates of cell apoptosis rate and numbers of cells in the G1 phase (p < .05 for all). These groups also showed significantly lower expression of the proteins PI3K, AKT, c-Myc, MMP-2, and MMP-9 but significantly increased expression of the protein P21 (p < .05). Transfecting muscone-treated SGC-7901 and MGC-803 cells with miRNA-145 inhibitor resulted in a significant recovery of biological activity (p < .05). Muscone suppresses the biological activity of SGC-7901 and MGC-803 gastric cancer cells in vitro via regulation of miRNA-145.

Role of Long Non-coding RNAs on Bladder Cancer

Bladder cancer (BC) is the most common malignant tumor in the urinary system, and its early diagnosis is conducive to improving clinical prognosis and prolonging overall survival time. However, few biomarkers with high sensitivity and specificity are used as diagnostic markers for BC. Multiple long non-coding RNAs (lncRNAs) are abnormally expressed in BC, and play key roles in tumorigenesis, progression and prognosis of BC. In this review, we summarize the expression, function, molecular mechanisms and the clinical significance of lncRNAs on bladder cancer. There are more than 100 dysregulated lncRNAs in BC, which are involved in the regulation of proliferation, cell cycle, apoptosis, migration, invasion, metabolism and drug resistance of BC. Meanwhile, the molecular mechanisms of lncRNAs in BC was explored, including lncRNAs interacting with DNA, RNA and proteins. Additionally, the abnormal expression of thirty-six lncRNAs is closely associated with multiple clinical characteristics of BC, including tumor size, metastasis, invasion, and drug sensitivity or resistance of BC. Furthermore, we summarize some potential diagnostic and prognostic biomarkers of lncRNA for BC. This review provides promising novel biomarkers in early diagnosis, prognosis and monitoring of BC based on lncRNAs.

Long non-coding RNA SNHG16, binding with miR-106b-5p, promoted cell apoptosis and inflammation in allergic rhinitis by up-regulating leukemia inhibitory factor to activate the JAK1/STAT3 signaling pathway

Allergic rhinitis (AR) is a type I hypersensitive disease. Long non-coding RNA (lncRNA) SNHG16 acts as an oncogene in a variety of tumors and promotes the occurrence of inflammation in many inflammatory diseases. The study aims to investigate the expression of SNHG16 and its potential biological functions in AR. RT-qPCR results showed that the expression of SNHG16 in AR was up-regulated. The AR cell model was constructed by stimulating primary nasal mucosal epithelial cells from AR patients with IL-13. After knocking down the expression of lncRNA SNHG16, cell apoptosis was detected by flow cytometry, and the expression of inflammatory factors was detected by ELISA. The results showed that SNHG16 promoted cell apoptosis and inflammation. Then, bioinformatics analysis was used to screen miRNAs bound with SNHG16. Luciferase reporter gene assay and RNA pull-down experiment were used to verify the relationship. We found that the expression of miR-106b-5p was down-regulated and leukemia inhibitory factor (LIF) expression was up-regulated in the AR cell model. The expression of phospho-Janus kinase 1 and p-signal transducer and activator of transcription 3 (STAT3) were detected by Western blotting. Silencing the expression of LIF could inhibit the activity of JAK1/STAT3 pathway and further inhibit cell apoptosis and the occurrence of inflammation. Then transfected SNHG16 shRNA alone or together with miR-106b-5p antagomir into the AR cell model, we found that silencing the expression of SNHG16 down-regulated the expression of LIF and inhibited the activity of the JAK1/STAT3 pathway, cell apoptosis, and inflammation. However, miR-106b-5p antagomir weakened its inhibitory effects. The role of SNHG16 in AR was further verified by the ovalbumin-induced AR mouse model in vivo. In conclusion, SNHG16 up-regulates LIF expression by binding with miR-106b-5p, thus promoting the activity of JAK1/STAT3 pathway, and promoting the development of AR. These results provide new targets for the treatment of AR and may help reduce the damage caused by AR.

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.

Explore prognostic biomarker of bladder cancer based on competing endogenous network

Bladder cancer (BC) is the most common tumor of the urinary tract. Increasing evidence showed that long non-coding RNA (lncRNA) is a critical regulator in cancer development and progression. However, the functions of lncRNAs in the development of BC remain mostly undefined. In the present study, based on RNA sequence profiles from The Cancer Genome Atlas database, we identified 723 lncRNAs, 157 miRNAs, and 1816 mRNAs aberrantly expressed in BC tissues. A competing endogenous RNA network, including 49 lncRNAs, 17 miRNAs, and 36 mRNAs, was then established. The functional enrichment analyses showed that the mRNAs in the ceRNA network mainly participated in ‘regulation of transcription’ and ‘pathways in cancer’. Moreover, the Cox regression analyses demonstrated that three lncRNAs (AC112721.1, TMPRSS11GP, and ADAMTS9-AS1) could serve as independent risk factors. We established a risk prediction model with these lncRNAs. Kaplan–Meier curve analysis showed that high-risk patients’ prognosis was lower than that of low-risk patients (P=0.001). The present study provides novel insights into the lncRNA-mediated ceRNA network and the potential of lncRNAs to be candidate prognostic biomarkers in BC, which could help better understand the pathological changes and pathogenesis of BC and be useful for clinical studies in the future.

LncRNA SNHG16 contributes to osteosarcoma progression by acting as a ceRNA of miR-1285-3p

Background

The long non-coding (lnc) RNA activated by small nucleolar RNA host gene 16 (SNHG16), which has been reported to play a vital role in a number of different types of cancer, is a novel lncRNA. However, following an osteosarcoma (OS) study, the expression pattern, biological roles, clinical values and potential molecular mechanism of SNHG16 remain unclear. In the current study, we aimed to examine its expression and possible function in osteosarcoma (OS).

Method

Cell proliferation was measured by colony formation assay and Cell Counting Kit-8 (CCK-8) in vitro, and xenograft transplantation assay in vivo. Meanwhile, we used transwell chambers to test cell migration and invasion was evaluated. Cell cycle and apoptosis was evaluated by flow cytometry assay. Immunoblotting and qPCR analysis was carried out to detect protein and gene expression, respectively. Luciferase reporter assay was used to predict the potential downstream genes.

Results

The present study demonstrated that SNHG16 is highly expressed in both the tissues of patients with OS, as well as OS cell lines, and its expression level was positively correlated with clinical stage and poor overall survival. Functional assays revealed that the depletion of SNHG16 inhibits OS growth, OS cell progression and promotes apoptosis both in vivo and in vitro. In addition, the present study revealed that microRNA-1285-3p expression levels can be decreased by SNHG16 acting as a ‘sponge’, and that this pathway takes part in OS tumor growth in vivo, and OS cell proliferation, invasion, migration and apoptosis in vitro.

Conclusions

The results from the present study demonstrate the role of lncRNA SNHG16 in OS progression, which is SNHG16 might exert oncogenic role in osteosarcoma (OS) by acting as a ceRNA of miR-1285-3p, and it may become a novel target in OS therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07933-2.

lncRNA SNHG16 Mediates Cell Proliferation and Apoptosis in Cholangiocarcinoma by Directly Targeting miR-146a-5p/GATA6 Axis

Cholangiocarcinoma (CCA) is a malignant tumour with high recurrence and mortality rates and poor prognosis. However, the pathogenic mechanism remains unclear. In the present study, we aimed to investigate the roles and regulatory mechanism of SNHG16 in the occurrence and development of CCA. Gene Expression Profiling Interactive Analysis (GEPIA) was used to predict the expressions of SNHG16 and GATA6 in CCA samples from TCGA database. The levels of SNHG16, miR-146a-5p and GATA6 were evaluated using qRT-PCR. CCK-8 and flow cytometry assays were conducted to evaluate cell proliferation and apoptosis, respectively. Western blotting was applied to analyse the protein levels of GATA6 and apoptosis-related proteins. SNHG16 was significantly elevated in CCA tissues from TCGA database and CCA cell lines. Moreover, downregulation of SNHG16 restricted cell proliferation and increased apoptotic rate of RBE and HuCCT1 cells. miR-146a-5p, a downstream target of SNHG16, was shown to be an intermediate mediator of GATA6 expression regulated by SNHG16. In addition, either the miR-146a-5p inhibitor or overexpression of GATA6 obviously impaired the regulatory effects of SNHG16 downregulation in RBE and HuCCT1 cells. These data demonstrated that SNHG16 promoted cell proliferation and repressed apoptosis by regulating the miR-146a-5p/GATA6 axis, which provides some helpful insights for the diagnosis and treatment of CCA.

Long Non-coding RNAs in Cisplatin Resistance in Osteosarcoma

OPINION STATEMENT

Osteosarcoma (OS), the most common primary malignant bone tumor, is a vastly aggressive disease in children and adolescents. Although dramatic progress in therapeutic strategies have achieved over the past several decades, the outcome remains poor for most patients with metastatic or recurrent OS. Nowadays, conventional treatment for OS patients is surgery combined with multidrug chemotherapy including doxorubicin, methotrexate, and cisplatin (CDDP). In this sense, cisplatin (CDDP) is one of the most drugs used in the treatment of OS but drug resistance to CDDP appears as a serious problem in the use of this drug in the treatment of OS. Thus, we consider that the understanding the molecular mechanisms and the genes involved that lead to CDDP resistance is essential to developing more effective treatments against OS. In this review, we present an outline of the key role of the long non-coding RNAs (lncRNAs) in CDDP resistance in OS. This overview is expected to contribute to understand the mechanisms of CDDP resistance in OS and the relationship of the expression regulation of several lncRNAs.

Silencing of LncRNA SNHG16 Downregulates Cyclin D1 (CCND1) to Abrogate Malignant Phenotypes in Oral Squamous Cell Carcinoma (OSCC) Through Upregulating miR-17-5p

Background

Targeting the long non-coding RNAs (LncRNAs)-microRNAs (miRNAs)-mRNA competing endogenous RNA (ceRNA) networks has been proved as an effective strategy to treat multiple cancers, including oral squamous cell carcinoma (OSCC). Based on this, the present study identified a novel LncRNA SNHG16/miR-17-5p/CCND1 signaling pathway that played an important role in regulating the pathogenesis of OSCC.

Methods

The expression levels of cancer-associated genes were examined by Real-Time qPCR and Western Blot at transcriptional and translated levels, respectively. CCK-8 assay was performed to determine cell proliferation, and cell apoptosis ratio was measured by the Annexin V-FITC/PI double staining assay. Transwell assay was performed to examine cell migration, and dual-luciferase reporter gene system assay was used to validate the ceRNA networks.

Results

LncRNA SNHG16 and CCND1 were upregulated, while miR-17-5p was downregulated in OSCC tissues and cell lines, compared to their normal counterparts. Also, miR-17-5p negatively correlated with both LncRNA SNHG16 and CCND1 mRNA, but LncRNA SNHG16 was positively relevant to CCND1 mRNA in OSCC tissues. By performing the gain- and loss-of-function experiments, we noticed that LncRNA SNHG16 overexpression aggravated the malignant phenotypes, such as cell proliferation, viability, migration and epithelial-mesenchymal transition (EMT) in OSCC cells, while LncRNA SNHG16 knock-down had opposite effects. Furthermore, our dual-luciferase reporter gene system evidenced that LncRNA SNHG16 sponged miR-17-5p to upregulate CCND1 in OSCC cells, and the inhibiting effects of LncRNA SNHG16 ablation on OSCC progression were abrogated by both downregulating miR-17-5p and overexpressing CCND1. Finally, the xenograft tumor-bearing mice models were established, and our data validated that LncRNA SNHG16 served as an oncogene to promote tumorigenicity of OSCC cells in vivo.

Conclusion

Taken together, targeting the LncRNA SNHG16/miR-17-5p/CCND1 axis hindered the development of OSCC, and this study provided potential diagnostic and therapeutic biomarkers for OSCC in clinic.

The effect of LncRNA SNHG16 on vascular smooth muscle cells in CHD by targeting miRNA-218-5p

PURPOSE

To explore the role of SNHG16 in coronary heart disease (CHD) and its effect on vascular smooth muscle cells via miR-218-5p.

METHODS

A quantitative real time polymerase chain reaction (qRT-PCR) assay was carried out to determine the expression of serum SNHG16 and miR-218-5p in the observation group before and after treatment and in the control group. Then, receiver operating characteristic (ROC) curves were drawn to analyze the value of SNHG16 and miR-218-5p in the diagnosis and prognosis prediction of CHD. Furthermore, purchased coronary artery smooth muscle cells (HCASMC) were transfected with SNHG16 mimics, SNHG16 inhibitor, miR-218-5p mimics, miR-218-5p inhibitor, or negative control, and then the cell proliferation, migration, apoptosis, and apoptosis-related proteins (Bax, Bcl-2, and Caspase-3) and Wnt/β-catenin signaling pathway-related proteins (c-myc and β-catenin) in the cells were detected.

RESULTS

Both SNHG16 and miR-218-5 had good predictive value for the development and recurrence of CHD (P < 0.001). In addition, cell experiments showed that inhibition of SNHG16 weakened the proliferation and migration of HCASMC cells and intensified their apoptosis, SNHG16 and miR-218-5p had the same binding sites, and the dual luciferase reporter assay revealed that the fluorescence activity of HG16-WT was inhibited by transfected miR-mimics, but enhanced by transfected miR-inhibitor (both P < 0.050). Furthermore, the rescue experiment revealed that the effect of inhibiting SNHG16 on HCASMC cells was completely reversed by miR-218-5p (P > 0.050).

CONCLUSIONS

Highly expressed SNHG16 targetedly regulates miR-218-5p and promotes the proliferation and migration of HCASMC via the Wnt/β-catenin signaling pathway, giving rise to CHD.

LncRNA HCP5 Promotes Cell Invasion and Migration by Sponging miR-29b-3p in Human Bladder Cancer

BACKGROUND

Bladder cancer (BC) is one of the most common malignant tumors in the urinary system. In this study, the roles of lncRNA HCP5 (human major histocompatibility complex p5) and miR-29b-3p in human BC were investigated. Their regulations involved in cell invasion and migration were also evaluated.

METHODS

Luciferase reporter assay was performed to detect the binding between miR-29b-3p and HCP5 or high-mobility group box 1 (HMGB1). Cell viability, migration, invasion and apoptosis were assessed by CCK-8, colony formation, transwell assay and flow cytometry, respectively. Expression levels of HMGB1/toll-like receptor 4 (TLR4) proteins were measured by Western blot. Xenograft model was built, and tumor volumes and weights were calculated.

RESULTS

The results revealed dysregulation of HCP5 and miR-29b-3p in BC samples and cells. HCP5 negatively regulated the expression of miR-29b-3p and enhanced cell viability, migration and invasion. MiR-29b-3p mediated the effect of HCP5 on cell viability, proliferation, migration and invasion in RT4 cells. In addition, miR-29b-3p could regulate the expression of HMGB1 through interaction with HMGB1.

CONCLUSION

The findings in this study supported that lncRNA HCP5 could promote cell invasion and migration by sponging miR-29b-3p in human BC.

LINC02738 Participates in the Development of Kidney Cancer Through the miR-20b/Sox4 Axis

Background

Long non-coding RNAs (lncRNAs) can affect tumorigenesis. Data from The Cancer Genome Atlas (TCAG) suggest that LINC02783 is highly expressed in renal cell carcinoma (RCC) and is expected to be a potential biological target. We conducted this study to verify this.

Patients and Methods

We conducted this study to verify the opinion that "LINC02783 is highly expressed in renal cell carcinoma (RCC) and is expected to be a potential biological target". We employed quantitative real-time polymerase chain reaction (qRT-PCR) to test LINC02783 expression in RCC tissues, CKK-8 assay and transwell assay to assess the viability and invasion of RCC cells, Western blot to quantify Sox-4 expression, dual-luciferase reporter (DLR) assay and RNA immunoprecipitation (RIP) assay to analyze the interaction between LINC02783 and miR-20b, in vivo experiments to test tumor formation.

Results

We detected high LINC02783 expression in RCC patients. Patients with higher LINC02783 levels had a markedly poorer prognosis. In vitro and in vivo, the down-regulation of LINC02783 suppressed the viability and invasion of RCC cells. The DLR assay results revealed that LINC02783 enhanced Sox-4 expression by regulating miR-20b. LINC02783 can act as a sponge for miR-20b to inhibit Sox-4 expression.

Conclusion

LINC02783 is highly expressed in RCC patients and indicates a poor prognosis. LINC02783 can affect the occurrence and progression of RCC through the miR-20b/Sox-4 axis, making it a promising target for the treatment of RCC.

LncRNA SNHG16 as a potential biomarker and therapeutic target in human cancers

Long non-coding RNAs (lncRNAs) represent an important class of RNAs comprising more than 200 nucleotides, which are produced by RNA polymerase II. Although lacking an open reading framework and protein-encoding activity, lncRNAs can mediate endogenous gene expression by serving as chromatin remodeler, transcriptional or post-transcriptional modulator, and splicing regulator during gene modification. In recent years, increasing evidence shows the significance of lncRNAs in many malignancies, with vital roles in tumorigenesis and cancer progression. Moreover, lncRNAs were also considered potential diagnostic and prognostic markers in cancer. The lncRNA small nuclear RNA host gene 16 (SNHG16), found on chromosome 17q25.1, represents a novel tumor-associated lncRNA. SNHG16 was recently found to exhibit dysregulated expression in a variety of malignancies. There are growing evidence of SNHG16's involvement in characteristics of cancer, including proliferation, apoptosis, together with its involvement in chemoresistance. In addition, SNHG16 has been described as a promising diagnostic and prognostic biomarker in cancer patients. The current review briefly summarizes recently reported findings about SNHG16 and discuss its expression, roles, mechanisms, and diagnostic and prognostic values in human cancers.

Knockdown of SNHG16 suppresses the proliferation and induces the apoptosis of leukemia cells via miR‑193a‑5p/CDK8

Although small nucleolar RNA host gene 16 (SNHG16) is known to exhibit auxo‑action in certain types of tumor, its role in leukemia remains unclear. The present study analyzed the role and mechanisms of action of SNHG16 in leukemia cells in order to identify therapeutic targets for this disease. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to determine SNHG16 expression in human leukemia cell lines. Using TargetScan 7.2 and dual‑luciferase reporter assay, the target genes of SNHG16 were verified. Following the downregulation of the expression of SNHG16 or its target genes, Cell Counting kit‑8 (CCK‑8) assay was performed to examine the viability of the leukemia cells. In addition, flow cytometry was performed to analyze the cell apoptotic rates, and colony formation assays were used to determine the cell proliferative ability. RT‑qPCR and western blot analysis were used to determine the association between SNHG16 and its target genes. SNHG16 was found to be abnormally highly expressed in acute myeloblastic leukemia cell lines, the knockdown of which weakened the viability of the leukemia cells, suppressed cell proliferation and promoted cell apoptosis. miR‑193a‑5p could bind to SNHG16, and its target gene was CDK8. Moreover, the expression of miR‑193a‑5p increased with the decrease in SNHG16 expression, while the inhibition of miR‑193a‑5p promoted the expression of CDK8. The downregulation of miR‑193a‑5p enhanced the viability of the leukemia cells, accelerated cell cloning and reduced cell apoptosis, which was completely opposite to the effects observed with the silencing of CDK8. The knockdown of SNHG16 suppressed the viability of the leukemia cells, suppressed cell proliferation, and induced cell apoptosis by regulating miR‑193a‑5p/CDK8. Thus, SNHG16 may prove to be a potential therapeutic target for the treatment of leukemia.

lncRNA OTUD6B-AS1 Exacerbates As2O3-Induced Oxidative Damage in Bladder Cancer via miR-6734-5p-Mediated Functional Inhibition of IDH2

Arsenic trioxide (As2O3) is a promising effective chemotherapeutic agent for cancer treatment; however, how and through what molecular mechanisms the oxidative damage of As2O3 is controlled remains poorly understood. Recently, the involvement of dysregulated long noncoding RNA ovarian tumor domain containing 6B antisense RNA1 (lncRNA OTUD6B-AS1) in tumorigenesis is established. Here, for the first time, we characterize the regulation of As2O3 in the oxidative damage against bladder cancer via lncRNA OTUD6B-AS1. As2O3 could activate lncRNA OTUD6B-AS1 transcription in bladder cancer cells, and these findings were validated in a xenograft tumor model. Functional assays showed that lncRNA OTUD6B-AS1 dramatically exacerbated As2O3-mediated oxidative damage by inducing oxidative stress. Mechanistically, As2O3 increased levels of metal-regulatory transcription factor 1 (MTF1), which regulates lncRNA OTUD6B-AS1, in response to oxidative stress. Further, lncRNA OTUD6B-AS1 inhibited mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) expression by stabilizing miR-6734-5p, which contributed to cytotoxicity by enhancing oxidative stress. Together, our findings offer new insights into the mechanism of As2O3-induced oxidative damage and identify important factors in the pathway, As2O3/lncRNA OTUD6B-AS1/miR-6734-5p/IDH2, expanding the knowledge of activity of As2O3 as cancer treatment.

Long noncoding RNAs, ENST00000598996 and ENST00000524265, are correlated with favorable prognosis and act as potential tumor suppressors in bladder cancer

Bladder cancer (BC) is a serious malignancy worldwide due to its distant metastasis and high recurrence rates. Increasing evidence has indicated that dysregulated long non-coding RNAs (lncRNAs) are involved in tumorigenesis and progression in multiple malignancies. However, their clinical significances, biological functions and molecular mechanisms in BC remain poorly understood. Hence, the present study investigated the expression profile of lncRNAs and mRNAs in five BC tissues and the corresponding adjacent normal specimens using high-throughput RNA sequencing (RNA-seq). A total of 103 differentially expressed (DE) lncRNAs were identified, including 35 upregulated and 68 downregulated ones in BC tissues. Similarly, a total of 2,756 DE-mRNAs were detected, including 1,467 upregulated and 1,289 downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, and lncRNA-miRNA-mRNA network analyses suggested that these dysregulated lncRNAs are potentially implicated in the onset and progression of BC. Subsequently, four lncRNAs (upregulated ENST00000433108; downregulated ENST00000598996, ENST00000524265 and ENST00000398461) and two mRNAs (upregulated CCNB1 and CDK1) in 64 pairs of BC and adjacent normal tissues and four BC cell lines were detected using reverse transcription-quantitative PCR and these results were consistent with the sequencing data. Additionally, Fisher's exact test, Kaplan-Meier plots, and Cox regression analyses were used for elucidating the clinical values of ENST00000598996 and ENST00000524265. Furthermore, a receiver operating characteristic curve was constructed to assess their diagnostic values. The low expression level of ENST00000598996 and ENST00000524265 was correlated with unfavorable clinicopathological parameters, and shorter progression-free and overall survival time, whereas, ENST00000433108 was not associated with either. The in vitro functional experiments also revealed that the overexpression of ENST00000598996 and ENST00000524265 decreased the proliferation, migration, and invasion abilities of BC cells. Collectively, the results of the present study provide a novel landscape of lncRNA and mRNA expression profiles in BC. In addition, the results also indicated that ENST00000598996 and ENST00000524265 may serve as tumor suppressors, potential diagnostic biomarkers and prognostic predictors for patients with BC.

Clinicopathological significance and prognosis of long noncoding RNA SNHG16 expression in human cancers: a meta-analysis

Background

Recent studies have highlighted the important role of long non-coding RNA SNHG16 in various human cancers. Here, we conducted a meta-analysis to investigate the effect of SNHG16 expression on clinicopathological features and prognosis in patients with different kinds of human cancers.

Methods

We performed a systematic search in electronic databases including PubMed, EMBASE, Cochrane Library and Web of Science, to investigate the potential association between SNHG16 expression and prognostic significance and clinical features in cancer patients. Odds ratios (ORs) or hazards ratios (HRs) with corresponding 95% confidence intervals (95% CIs) were pooled to estimate the prognosis value of SNHG16 by StataSE 15.0 software.

Results

A total of 16 eligible studies with 1299 patients were enrolled in our meta-analysis. The results revealed that increased expression level of SNHG16 was significantly associated with larger tumor size (OR: 3.357; 95% CI: 2.173–5.185; P < 0.001), advanced TNM stage (OR: 2.930; 95% CI: 1.522–5.640; P = 0.001) and poor histological grade (OR: 3.943; 95% CI: 1.955–7.952; P < 0.001), but not correlated with smoking status (P = 0.489), sex (P = 0.932), distant metastasis (P = 0.052), or lymph node metastasis (P = 0.155). Moreover, the pooled HR showed that elevated expression SNHG16 was associated with a significantly poorer overall survival (OS) (HR = 1.866, 95% CI: 1.571–2.216, P < 0.001). For the set of cancer types, high expression of SNHG16 was significantly associated with shorter OS in patients with cancers of the urinary system (HR: 2.523, 95% CI:1.540–4.133; P <0.001), digestive system (HR: 2.406, 95% CI:1.556–3.721; P <0.001), and other cancers (including glioma and non-small cell lung cancer) (HR: 1.786, 95% CI:1.406–2.267; P <0.001).

Conclusions

LncRNA SNHG16 overexpression might serve as an unfavorable prognostic factor, which provides a basis for medical workers to evaluate the prognosis of patients and to help the decision-making process.

Genome-wide identification of the essential protein-coding genes and long non-coding RNAs for human pan-cancer

MOTIVATION

Genome-scale CRISPR/Cas9 system has been a democratized gene editing technique and widely used to investigate gene functions in some biological processes and diseases especially cancers. Aiming to characterize gene aberrations and assess their effects on cancer, we designed a pipeline to identify the essential genes for pan-cancer.

METHODS

CRISPR screening data were used to identify the essential genes that were collected from published data and integrated by Robust Rank Aggregation algorithm. Then, hypergeometrics test and random walks with restart (RWR) were used to predict additional essential genes on broader scale. Finally, the expression status and potential roles of these genes were explored based on TCGA portal and regulatory network analysis.

RESULTS

We collected 926 samples from 10 CRISPR-based screening studies involving 33 different types of cancer to identify cancer-essential genes, which consists of 799 protein-coding genes (PCGs) and 97 long non-coding RNAs (lncRNAs). Then, we constructed a 'bi-colored' network with both PCGs and lncRNAs and applied it to predict additional essential genes including 495 PCGs and 280 lncRNAs on a broader scale using hypergeometrics test and RWR. After obtaining all essential genes, we further investigated their potential roles in cancer and found that essential genes have higher and more stable expression levels, and are associated with multiple cancer-associated biological processes and survival time. The regulatory network analysis detected two intriguing modules of essential genes participating in the regulation of cell cycle and ribosome biogenesis in cancer.

AVAILABILITY AND IMPLEMENTATION

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SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Up-regulation of SNHG16 induced by CTCF accelerates cardiac hypertrophy by targeting miR-182-5p/IGF1 axis

Long non-coding RNA (lncRNA) SNHG16 has been reported to be significant regulators in multiple cancers. However, never has the relationship between it and cardiac hypertrophy been studied until now. In this study, angiotensin II (Ang II)-treated cardiomyocytes isolated from neonatal mice were used as a model of cardiac hypertrophy in vitro. Real-time quantitative polymerase chain reaction was performed to measure the expression of SNHG16, miR-182-5p, and insulin-like growth factor 1 (IGF1). The relationship between SNHG16 and its downstream genes were corroborated by RNA pull-down and luciferase reporter experiments. Western blot was conducted to detect the expression of markers of hypertrophy. The results disclosed that SNHG16 expression was in a high level in the cardiac hypertrophic model. Down-regulation of SNHG16 could decline the expression of hypertrophic markers and reduce cell surface area induced by Ang II. Moreover, SNHG16 was discovered to be activated by transcription factor CCCTC-binding factor. In addition, SNHG16 could enlarge cell surface area and increase the expression of hypertrophic markers by inhibiting miR-182-5p expression in Ang II-treated cardiomyocytes. Finally, overexpression of IGF1 could rescue the effects of silenced SNHG16 on cardiac hypertrophy cells. In brief, our study illustrated that silenced SNHG16 repressed Ang II-imposed cardiac hypertrophy via targeting miR-182-5p/IGF1 axis.

LncRNA-SNHG16 Silencing Inhibits Prostate Carcinoma Cell Growth, Downregulate GLUT1 Expression and Reduce Glucose Uptake

Background

lncRNA-SNHG16 was identified as an oncogene in many cancers, but its involvement in prostate carcinoma is unknown.

Material and Method

Expression of lncRNA-SNHG16 and glucose transporter 1 (GLUT-1) in 52 prostate carcinoma tissues and 36 normal prostate tissues was analyzed by RT-qPCR. Transfections were performed to analyze gene interactions. Cell proliferation was analyzed by cell proliferation assay.

Results

Overexpression of lncRNA-SNHG16 effectively distinguished prostate carcinoma patients from normal ones. Expression levels of lncRNA-SNHG16 and GLUT-1 mRNA were significantly and positively correlated across prostate carcinoma tissues. In vitro cancer cell experiments revealed that lncRNA-SNHG16 siRNA silencing downregulated the expressions of GLUT-1 and reduced glucose uptake. lncRNA-SNHG16 siRNA silencing also significantly inhibited prostate carcinoma cell proliferation. However, lncRNA-SNHG16 siRNA silencing did not affect the normal prostate.

Conclusion

In conclusion, lncRNA-SNHG16 might be a possible treatment target for prostate cancer.

Biological and clinical relevance of metastasis-associated long noncoding RNAs in esophageal squamous cell carcinoma: A systematic review

Esophageal squamous cell carcinoma (ESCC) is a foremost cancer-related death worldwide owing to rapid metastasis and poor prognosis. Metastasis, as the most important reason for death, is biologically a multifaceted process involving a range of cell signaling pathways. Long noncoding RNAs (lncRNAs), as transcriptional regulators, can regulate numerous genomic processes and cellular processes such as cell proliferation, migration, and invasion. LncRNAs have also been shown to involve in/regulate the cancer metastasis-related signaling pathways. Hence, they have increasingly been brought to international attention in molecular oncology research. A number of researchers have attempted to reveal the biological and clinical relevance of lncRNAs in ESCC tumourigenesis and metastasis. The aberrant expression of these molecules in ESCC has regularly been reported to involve in various cellular processes and clinical features, including diagnosis, prognosis, and therapeutic responses. Here, we especially consider the pathways in which lncRNAs act as metastasis-mediated effectors, mainly by interacting with epithelial-mesenchymal transition-associated factors. We review the biological roles of lncRNAs through involving in ESCC metastasis as well as the clinical significance of the metastasis-related lncRNAs in cancer diagnosis and prognosis.

The USP21/YY1/SNHG16 axis contributes to tumor proliferation, migration, and invasion of non-small-cell lung cancer

Deubiquitinases (DUBs) and noncoding RNAs have been the subjects of recent extensive studies regarding their roles in lung cancer, but the mechanisms involved are largely unknown. In our study, we used The Cancer Genome Atlas data set and bioinformatics analyses and identified USP21, a DUB, as a potential contributor to oncogenesis in non-small-cell lung cancer (NSCLC). We further demonstrated that USP21 was highly expressed in NSCLCs. We then conducted a series of in vitro and in vivo assays to explore the effect of USP21 on NSCLC progression and the underlying mechanism involved. USP21 promoted NSCLC cell proliferation, migration, and invasion and in vivo tumor growth by stabilizing a well-known oncogene, Yin Yang-1 (YY1), via mediating its deubiquitination. Furthermore, YY1 transcriptionally regulates the expression of SNHG16. Moreover, StarBase bioinformatics analyses predicted that miR-4500 targets SNHG16 and USP21. A series of in vitro experiments indicated that SNHG16 increased the expression of USP21 through miR-4500. In summary, the USP21/YY1/SNHG16 axis plays a role in promoting the progression of NSCLC. Therefore, the USP21/YY1/SNHG16/miR-4500 axis may be a potential therapeutic target in NSCLC treatment.

Therapies targeting a molecular feedback loop involved in tumor growth may prove valuable for treating non-small-cell lung cancer. Fangbao Ding, Jianbing Huang, and co-workers at Shanghai Jiao Tong University in Shanghai, China, have shown how an enzyme called USP21 promotes cancer cell proliferation and tumor growth in non-small-cell lung cancer. The team took cancerous and non-cancerous lung tissue samples from 42 patients, and analyzed the expression and behavior of USP21. The enzyme was highly expressed in cancerous tissues, where it stabilized a known gene with the potential to cause cancer called YY1. This gene also regulated the expression of a particular RNA molecule, which in turn worked to increase levels of USP21. This cyclical process encouraged the proliferation, migration and invasion of non-small-cell lung cancer cells, and may provide a future therapeutic target.

LncRNA SNHG16 promotes non-small cell lung cancer development through regulating EphA2 expression by sponging miR-520a-3p

BACKGROUND

Recent evidence has found that lncRNA small nucleolar RNA host gene 16 (SNHG16) was associated with cell carcinogenesis in NSCLC. Here, we further investigated the precise functions and mechanisms of SNHG16 in NSCLC progression.

METHODS

The expression of SNHG16, microRNA (miR)-520a-3p and EPH Receptor A2 (EphA2) was measured using quantitative real-time polymerase chain reaction and western blot, respectively. Cell proliferation was determined using 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay. The migrated and invaded cells were measured by Transwell assay. Flow cytometry was used to detect apoptotic cells. The interaction between miR-520a-3p and SNHG16 or EphA2 was confirmed using a dual-luciferase reporter assay.

RESULTS

We found that SNHG16 was upregulated in NSCLC tissues and cell lines, knockdown of SNHG16 inhibited cell proliferation, migration, invasion and induced apoptosis in vitro as well as suppressed tumor growth in vivo. MiR-520a-3p directly bound to SNHG16 and miR-520a-3p, and SNHG16 acted as a ceRNA in regulating EphA2 through competitively binding to miR-520a-3p. Additionally, rescue assay exhibited the anticancer activity mediated by SNHG16 knockdown on NSCLC could be reversed by miR-520a-3p inhibition or EphA2 overexpression.

CONCLUSION

SNHG16 promoted NSCLC development by regulating the miR-520a-3p/EphA2 axis, suggesting novel insights for the pathogenesis of NSCLC and new potential therapeutic targets for the treatment of NSCLC.

KEY POINTS

Knockdown of SNHG16 inhibited NSCLC cell proliferation, migration, invasion and induced apoptosis in vitro as well as suppressed tumor growth in vivo. SNHG16 directly interacted with miR-520a-3p. EphA2 was a target of miR-520a-3p. SNHG16 could regulate the expression of EphA2 by binding to miR-520a-3p. SNHG16 promoted NSCLC development by regulating the miR-520a-3p/EphA2 axis.

Long non-coding RNA in bladder cancer

Bladder cancer (BC) is the ninth most common malignant disease and ranks fourteenth in cancer mortality worldwide. Moreover, among cancers, the incidence and mortality of BC in males increased to the 6th and 9th place, respectively. The overall survival (OS) declines dramatically as the cancer progresses, especially when urothelial cells transition from noninvasive to invasive. It is well known that epithelial cells can acquire invasive properties and a propensity to metastasize through the epithelial-to-mesenchymal transition (EMT) process in tumourigenesis and progression. However, the potential molecular mechanisms and key pathways are still unclear. As the sequencing technology advances, long non-coding RNAs (lncRNAs) have been proven to play an important role in regulating biological processes and cellular pathways. Here, we reviewed important lncRNAs, such as H19, UCA1 and MALAT1, that participate in the malignant phenotype of BC and regulate EMT signalling networks in the invasion-metastasis cascade during BC development. We further discuss MALAT1, PCAT-1 and SPRY4-IT1, and also urine and blood exosomal H19 and PTENP as potential noninvasive biomarkers. Moreover, antisense oligonucleotides (ASOs) and a double-stranded DNA plasmid (BC-819) have been designed for use in preclinical cancer models and clinical trials in patients. Therefore, the results of investigations have gradually prompted the utility of lncRNAs.

SNHG16: A Novel Long-Non Coding RNA in Human Cancers

Long noncoding RNAs (lncRNAs) have recently been considered as central regulators in diverse biological processes controlling tumorigenesis. Small nucleolar RNA host gene 16 (SNHG16) is an important tumor-associated lncRNA mainly involved in tumorigenesis and progression by competing with endogenous RNA (ceRNA) which sponges tumor-suppressive microRNA (miRNA), and by its recruitment mechanism. SNHG16 is overexpressed in tumor tissues and cell lines of different kinds of cancers, and its presence is associated with a poor clinical prognosis. Reviewing all publications about SNHG16 revealed that it plays a key role in the different hallmarks that define human cancer, including promoting proliferation, activating migration and invasion, inhibiting apoptosis, affecting lipid metabolism and chemoresistance. This review highlights the role that the aberrant expression of SNHG16 plays in the development and progression of cancer, and suggests that SNHG16 may function as a potential biomarker and therapeutic target for human cancers.

Role of SNHG16 in human cancer

A growing body of evidence suggests that long non-coding RNAs (lncRNAs), a novel class of non-coding endogenous single-stranded RNA, play a key role in multiple physiological and pathological processes through transcriptional interference, post-transcriptional regulation, and epigenetic modification. Furthermore, many studies have shown that lncRNAs-as oncogenes or tumour suppressors-play an important role in the occurrence and development of human cancers. Small nucleolar RNA host gene 16 (SNHG16) was initially identified as an oncogenic lncRNA in neuroblastoma, and has since been identified as a carcinogenic regulator of various malignant tumours. Overexpression of SNHG16 is associated with clinical and pathological characteristics of cancer patients, and regulates cell proliferation, apoptosis, invasion and metastasis through a variety of potential mechanisms. Therefore, SNHG16 may be a promising biomarker and therapeutic target for cancers. In this review, we summarize the biological function, related mechanisms and potential clinical significance of SNHG16 in multiple human cancers.