Upregulation of Long Noncoding RNA TUG1 Promotes Bladder Cancer Cell Proliferation, Migration, and Invasion by Inhibiting miR-29c

Bladder cancer biomarkers: current approaches and future directions

Bladder cancer is a significant health concern worldwide, necessitating effective diagnostic and monitoring strategies. Biomarkers play a crucial role in the early detection, prognosis, and treatment of this disease. This review explores the current landscape of bladder cancer biomarkers, including FDA-approved molecular biomarkers and emerging ones. FDA-approved molecular biomarkers, such as BTA stat, BTA TRAK, and NMP22, have been instrumental in diagnosing and monitoring bladder cancer. These biomarkers are derived from urinary samples and are particularly useful due to their sensitivity and specificity. As we move forward, we should continue to seek ways to optimize our processes and outcomes, these markers remain seriously challenged in the detection of early bladder cancer due to their limited sensitivity and specificity. For instance, sensitivities of BTA stat in bladder tumor detection have varied between 40-72%, while its specificities vary from 29-96%. In the same way, 70% sensitivity and 80% specificity have been recorded for BTA TRAK, while 11-85.7% sensitivity and 77-100% specificity have been documented for NMP22 BladderChek. The given variations, especially the low sensitivity in the diagnosis of bladder cancer at an early stage call for the invention of better diagnostic systems. Moreover, different sample collection and handling procedures applied in different laboratories further contribute to inconsistent results obtained. Extracellular vesicles (EVs) and exosomes, which carry a vast number of proteins, are being considered as potential biomarkers. Although these markers show promise, challenges remain due to non-standardized isolation techniques and lack of reproducibility across studies. Moreover, the discovery of new potential biomarkers is ongoing. For instance, the UBC® Rapid test and UBC ELISA kit, the XPERT BC Monitor, BC UroMark, TaqMan® Arrays, Soluble FAS (sFAS), Bladder tumor fibronectin (BTF), and IGF2 and MAGE-A3 are among the newest biomarkers under investigation. In conclusion, while bladder cancer biomarkers have shown great promise, more research is needed to standardize the testing procedures and validate these biomarkers in a clinical setting. This will pave the way for more accurate and efficient diagnosis and monitoring of bladder cancer, ultimately improving patient outcomes.

lncRNA TUG1 regulates Smac/DIABLO expression by competitively inhibiting miR-29b and modulates the apoptosis of lens epithelial cells in age-related cataracts

BACKGROUND

As one of the early discovered long non-coding RNAs (lncRNA), taurine upregulation gene 1 ( TUG1 ) has been widely expressed in a variety of tumors. Moreover, it promotes cell proliferation, differentiation, apoptosis, and migration. However, our understanding of its importance in the pathogenesis of cataracts remains limited. This study aimed to explore the mechanism by which lncRNA TUG1 mediates lens epithelial cell apoptosis in age-related cataracts (ARC) by regulating the microRNAs (miR-29b)/second mitochondria-derived activator of caspases axis, and to identify more non-surgical strategies for cataract treatment.

METHODS

The messenger RNA expression levels of TUG1 , miR-29b, and Smac were detected using quantitative real-time polymerase chain reaction in vivo and in vitro . The expression of the Smac protein was analyzed by Western blotting and immunofluorescence. Flow cytometry and cell counting kit-8 assays were used to detect the cell apoptosis and proliferation rates, respectively. The targeted regulatory relationship between lncRNA TUG1 , miR-29b, and Smac was verified by viral vector construction, co-transfection, nuclear and cytoplasmic separation, luciferase reporter assays, and RNA immunoprecipitation.

RESULTS

TUG1 and Smac were expressed at high levels in ARC and HLE-B3 cells treated with 200 μmol/L H 2 O 2 , whereas miR-29b expression was decreased. In vitro cell experiments confirmed that down-regulation of TUG1 could inhibit the apoptosis of lens epithelial cells. Mechanistically, Smac expression was negatively regulated by miR-29b. TUG1 competitively inhibited miR-29b expression and caused greater release of Smac. In addition, miR-29b partially reversed the effects of TUG1 on human lens epithelial cell line cells.

CONCLUSIONS

lncRNA TUG1 increases Smac expression and promotes apoptosis of lens epithelial cells in ARC by competitively inhibiting miR-29b. This mechanism is the cytological basis for ARC formation. Based on these results, the lncRNA TUG1/miR29b/Smac axis may be a new molecular pathway that regulates ARC development.

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.

Long noncoding RNA TUG1 decreases bladder cancer chemo-sensitivity toward doxorubicin through elevating KPNA2 expression and activating the PI3K/AKT pathway via adsorbing miR-582-5p

Long noncoding RNA taurine-upregulated gene1 (TUG1) has been reported to be implicated in the chemo-resistance of bladder cancer. Hence, this study aimed to survey regulatory mechanism by which TUG1 regulates the chemo-resistance of bladder cancer cells to doxorubicin (DOX). Relative expression of TUG1, miR-582-5p, and karyopherin alpha 2 (KPNA2) was detected by qRT-PCR. The viability and proliferation of DOX-resistant bladder cancer cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Protein levels were measured by western blot analysis. The apoptosis, migration, and invasion of DOX-resistant bladder cancer cells were determined by flow cytometry or transwell assays. The relationship between TUG1 or KPNA2 and miR-582-5p was verified by dual-luciferase reporter assay. TUG1 and KPNA2 were upregulated while miR-582-5p was downregulated in resistant bladder cancer tissues and cells. TUG1 inhibition elevated cell chemo-sensitivity, facilitated cell apoptosis, and curbed proliferation, migration, invasion, and autophagy of DOX-resistant bladder cancer cells. Also, TUG1 acted as a sponge for miR-582-5p, and miR-582-5p inhibitor reversed TUG1 knockdown-mediated influence on DOX chemo-sensitivity and malignant behaviors in DOX-resistant bladder cancer cells. Furthermore, miR-582-5p targeted KPNA2, and KPNA2 overexpression counteracted the inhibitory impact of miR-582-5p mimic on DOX chemo-resistance and malignant behaviors in DOX-resistant bladder cancer cells. Additionally, TUG1 silencing inactivated the PI3K/AKT pathway through sponging miR-582-5p. TUG1 sponged miR-582-5p to increase KPNA2 expression and activated the KPNA2/PI3K/AKT pathway, thereby elevating DOX chemo-resistance and malignant behaviors in bladder cancer cells.

MiR-29c inhibits the metastasis of oral squamous cell carcinoma and promotes its cell cycle arrest by targeting SERPINH1

Background

A large number of studies have shown that the imbalance of micro RNA (miRNA) and its target genes can promote the development of tumors. The purpose of this study was to investigate the biological role and molecular mechanism of serpin peptidase inhibitor clade H member 1 (SERPINH1) and its upstream regulator miR-29c in oral squamous cell carcinoma (OSCC).

Methods

The expression levels of SERPINH1 and miR-29c were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and western blotting. The proliferation, apoptosis, metastasis, and cell cycle were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, would healing assay, transwell assay, flow cytometry, and dual luciferase reporter assay.

Results

High expression of SERPINH1 was detected in patients with OSCC and it can be used as a prognostic biomarker for OSCC. Cell function experiments showed that silencing the expression of SERPINH1 inhibited the proliferation and migration of OSCC cells and caused cell cycle arrest at S phase. Bioinformatics analysis showed that there was a binding site between miR-29c and SERPINH1, indicating that miR-29c may regulate the expression of SERPINH1. In addition, miR-29c overexpression inhibited the proliferation and metastasis of OSCC cells, and the subsequent rescue experiment showed that SERPINH1 overexpression can reverse the inhibitory effect of miR-29c in OSCC cell proliferation, migration, apoptosis, and cell cycle arrest.

Conclusions

The miRNA, miR-29c can regulate the proliferation, migration, invasion, and cell cycle of OSCC cells by targeting SERPINH1.

LncRNA PCAT6 activated by SP1 facilitates the progression of breast cancer by the miR-326/LRRC8E axis

Breast cancer is an aggressive malignancy with high morbidity in females worldwide. Extensive studies reveal that long noncoding RNAs (lncRNAs) are abnormally expressed and act as key regulators in various cancers, including breast cancer. In this work, we investigated the role and regulatory mechanism of lncRNA prostate cancer-associated transcript 6 (PCAT6) in breast cancer progression. Our findings revealed that PCAT6 was overexpressed in breast cancer tissues and cell lines. Furthermore, elevation of PCAT6 reflected an adverse prognosis of patients. Functional experiments indicated that PCAT6 knockdown hampered cell proliferation, facilitated apoptosis and cell cycle arrest in vitro, and inhibited tumor growth in vivo. We also found that the transcription factor SP1 could bind to the PCAT6 promoter and promoted its expression. Subsequently, it was verified that PCAT6 was a molecular sponge for microRNA-326 (miR-326), and the leucine-rich repeat containing the eight family member E (LRRC8E) was a direct target of miR-326. Rescue assays revealed that LRRC8E overexpression attenuated the suppressive effect of PCAT6 knockdown on cellular progression of breast cancer. In summary, this study demonstrated that SP1-activated PCAT6 promoted the malignant behaviors of breast cancer cells by regulating the miR-326/LRRC8E axis.

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.

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.

Non-coding Natural Antisense Transcripts: Analysis and Application

Non-coding natural antisense transcripts (ncNATs) are regulatory RNA sequences that are transcribed in the opposite direction to protein-coding or non-coding transcripts. These transcripts are implicated in a broad variety of biological and pathological processes, including tumorigenesis and oncogenic progression. With this complex field still in its infancy, annotations, expression profiling and functional characterisations of ncNATs are far less comprehensive than those for protein-coding genes, pointing out substantial gaps in the analysis and characterisation of these regulatory transcripts. In this review, we discuss ncNATs from an analysis perspective, in particular regarding the use of high-throughput sequencing strategies, such as RNA-sequencing, and summarize the unique challenges of investigating the antisense transcriptome. Finally, we elaborate on their potential as biomarkers and future targets for treatment, focusing on cancer.

LncRNATUG1 Facilitates Th2 Cell Differentiation by Targeting the miR-29c/B7-H3 Axis on Macrophages

The role of long non-coding RNAs (lncRNA) in asthma remains unclear. In this study, we examined the role of long non-coding RNA taurine upregulated 1 (lncRNA TUG1) in asthma. We found that lncRNA TUG1 is one of the differentially expressed lncRNAs in the monocytes of asthmatic children and is associated with Th cell differentiation. LncRNA TUG1 and miR-29c are mainly distributed in the cytoplasm of macrophages. Our data suggested that lncRNA TUG1 increased in macrophages stimulated by House Dust Mite in a dose-dependent manner. Using loss- and gain of function strategy, we found that miR-29c might regulate Th2 cell differentiation by directly targeting co-stimulatory molecule B7-H3. Furthermore, down-regulation of lncRNA TUG1 decreased the level of GATA3 in CD4+T cells and was associated with miR-29c/B7-H3 axis. Moreover, the dual-luciferase reporter assay confirmed that lncRNA TUG1 serves as a competing endogenous RNA to sponge miR-29c. According to the rescue experiment, lncRNA TUG1 regulated Th2 cell differentiation via miR-29c. These data suggest that lncRNA TUG1 in macrophages regulates Th2 cell differentiation via miR-29c/B7-H3 axis.

PP7080 expedites the proliferation and migration of lung adenocarcinoma cells via sponging miR-670-3p and regulating UHRF1BP1

BACKGROUND

An increasing body of evidence has revealed that long non-coding RNAs play a significant part in a variety of human cancers, including lung adenocarcinoma (LUAD).

METHODS

The expression of PP7080, miR-670-3p and UHRF1BP1 in LUAD cells and tissues was detected using a quantitative real-time polymerase chain reaction. The role of PP7080 in LUAD cells was validated by CCK-8, flow cytometry, colony formation, transwell and wound healing assays. The binding capacity between PP7080/UHRF1BP1 and miR-670-3p was confirmed by luciferase reporter assays. Moreover, the interactional mechanism among PP7080, miR-670-3p and UHRF1BP1 was determined by means of RNA immunoprecipitation and western blot assays.

RESULTS

The expression level of PP7080 is up-regulated in LUAD cells and tissues compared to their matched controls. Down-regulation of PP7080 restrained the proliferative and migratory abilities of LUAD cells, but induced cell apoptosis. PP7080 up-regulation led to the opposite results. Moreover, the binding ability between miR-670-3p and PP7080/UHRF1BP1 in LUAD cells was confirmed. A rescue assay revealed that PP7080 contributes to LUAD development by modulating the miR-670-3p/UHRF1BP1 signaling pathway.

CONCLUSIONS

PP7080 expedites the proliferation and migration of LUAD cell via sponging miR-670-3p and modulating UHRF1BP1.

LncRNA TUG1/miR-29c-3p/SIRT1 axis regulates endoplasmic reticulum stress-mediated renal epithelial cells injury in diabetic nephropathy model in vitro

Long non-coding RNAs (lncRNAs) are important regulators in diabetic nephropathy. In this study, we investigated the potential role of lncRNA TUG1 in regulating endoplasmic reticulum stress (ERS)-mediated apoptosis in high glucose induced renal tubular epithelial cells. Human renal tubular epithelial cell line HK-2 was challenged with high glucose following transfection with lncRNA TUG1, miR-29c-3p mimics or inhibitor expression plasmid, either alone or in combination, for different experimental purposes. Potential binding effects between TUG1 and miR-29c-3p, as well as between miR-29c-3p and SIRT1 were verified. High glucose induced apoptosis and ERS in HK-2 cells, and significantly decreased TUG1 expression. Overexpressed TUG1 could prevent high glucose-induced apoptosis and alleviated ERS via negatively regulating miR-29c-3p. In contrast, miR-29c-3p increased HK-2 cells apoptosis and ERS upon high glucose-challenge. SIRT1 was a direct target gene of miR-29c-3p in HK-2 cells, which participated in the effects of miR-29c-3p on HK-2 cells. Mechanistically, TUG1 suppressed the expression of miR-29c-3p, thus counteracting its function in downregulating the level of SIRT1. TUG1 regulates miR-29c-3p/SIRT1 and subsequent ERS to relieve high glucose induced renal epithelial cells injury, and suggests a potential role for TUG1 as a promising diagnostic marker of diabetic nephropathy.

Role of long noncoding RNA taurine-upregulated gene 1 in cancers

Long non-coding RNAs (lncRNAs) are a group of non-protein coding RNAs with a length of more than 200 bp. The lncRNA taurine up-regulated gene 1 (TUG1) is abnormally expressed in many human malignant cancers, where it acts as a competitive endogenous RNA (ceRNA), regulating gene expression by specifically sponging its corresponding microRNAs. In the present review, we summarised the current understanding of the role of lncRNA TUG1 in cancer cell proliferation, metastasis, angiogenesis, chemotherapeutic drug resistance, radiosensitivity, cell regulation, and cell glycolysis, as well as highlighting its potential application as a clinical biomarker or therapeutic target for malignant cancer. This review provides the basis for new research directions for lncRNA TUG1 in cancer prevention, diagnosis, and treatment.

Pan-cancer characterization of long non-coding RNA and DNA methylation mediated transcriptional dysregulation

BACKGROUND

Disruption of DNA methylation (DNAm) is one of the key signatures of cancer, however, detailed mechanisms that alter the DNA methylome in cancer remain to be elucidated.

METHODS

Here we present a novel integrative analysis framework, called MeLncTRN (Methylation mediated LncRNA Transcriptional Regulatory Network), that integrates genome-wide transcriptome, DNA methylome and copy number variation profiles, to systematically identify the epigenetically-driven lncRNA-gene regulation circuits across 18 cancer types.

FINDING

We show that a significant fraction of the aberrant DNAm and gene expression landscape in cancer is associated with long noncoding RNAs (lncRNAs). We reveal distinct types of regulation between lncRNA modulators and target genes that are operative in either only specific cancers or across cancers. Functional studies identified a common theme of cancer hallmarks that lncRNA modulators may participate in. The coupled lncRNA gene interactions via DNAm also serve as markers for classifications of cancer subtypes with different prognoses.

INTERPRETATION

Our study reveals a vital layer of DNAm and associated expression regulation for many cancer-related genes and we also provide a valuable database resource for interrogating epigenetically mediated lncRNA-gene interactions in cancer.

FUNDING

National Natural Science Foundation of China [91959106, 31871255].

Long non-coding RNA TUG1/microRNA-187-3p/TESC axis modulates progression of pituitary adenoma via regulating the NF-κB signaling pathway

The molecule mechanisms of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in human diseases have been broadly studied recently, therefore, our research aimed to assess the effect of lncRNA taurine upregulated gene 1 (TUG1)/miR-187-3p/tescalcin (TESC) axis in pituitary adenoma (PA) by regulating the nuclear factor-kappa B (NF-κB) signaling pathway. We observed that TUG1 was upregulated in PA tissues and was associated with invasion, knosp grade and tumor size. TUG1 particularly bound to miR-187-3p. TUG1 knockdown inhibited cell proliferation, invasion, migration, and epithelial–mesenchymal transition, promoted apoptosis, and regulated the expression of NF-κB p65 and inhibitor of κB (IκB)-α in PA cells lines in vitro, and also inhibited tumor growth in vivo, and these effects were reversed by miR-187-3p reduction. Similarly, miR-187-3p elevation inhibited PA cell malignant behaviors and modulated the expression of NF-κB p65 and IκB-α in PA cells, and reduced in vivo tumor growth as well. TUG1 inhibition downregulated TESC, which was targeted by miR-187-3p. In conclusion, this study suggests that TUG1 sponges miR-187-3p to affect PA development by elevating TESC and regulating the NF-κB signaling pathway.

LncRNA Taurine Upregulated Gene 1 as a Potential Biomarker in the Clinicopathology and Prognosis of Multiple Malignant Tumors: A Meta-Analysis

Background

The lncRNA taurine upregulated gene 1 (TUG1) is a recently identified potential biomarker in cancer. However, its prognostic role in various cancers is inconsistent among published data. We conducted this meta-analysis to comprehensively confirm the prognostic effect of TUG1 in malignant tumors.

Methods

We systemically analyzed the prognostic-predictive capacity of TUG1 through amplifying sample sizes and cancer types. STATA 12.0 was applied for this meta-analysis.

Results

A total of 57 eligible studies were included in our meta-analysis. The pooled results suggested that overexpression of TUG1 was significantly correlated with unfavorable overall survival (OS) (HR = 1.70, p < 0.001), shorter recurrence-free survival (RFS) (HR = 2.40, p ≤ 0.001), and shorter event-free survival (EFS) (HR = 1.88, p < 0.001) in patients with cancer. In the subgroup analysis by cancer type, elevated TUG1 expression was associated with poorer survival in patients with gastrointestinal cancer, urinary tumors, gynecological tumors, hematological tumors, and osteosarcoma. However, high expression of TUG1 in respiratory tumors indicated a better prognosis. There was no correlation between high TUG1 expression and OS in patients with head and neck neoplasms or melanoma. Additionally, overexpression of TUG1 was found to be correlated with low-grade tumor differentiation, advanced tumor stage, positive lymphatic metastasis, and positive distant metastasis.

Conclusions

High TUG1 expression correlates with poor prognosis and advanced clinicopathological features, verifying the prognostic-predictive capacity of TUG1 in tumors, especially in gastrointestinal cancer, urinary tumors, gynecological tumors, hematological tumors, and osteosarcoma. Meanwhile, the prognostic role of TUG1 in respiratory tumor may be opposite to other tumors.

[Mir-29c-3p targeting TUG1 affects migration and invasion of bladder cancer cells by regulating CAPN7 expression]

OBJECTIVE

To investigate the mechanism by which long non-coding RNA TUG1 affects bladder cancer cell migration and invasion.

METHODS

The expressions of TUG1 and miR-29c-3p were examined by quantitative RT-PCR (qRT-PCR) in 10 bladder cancer tissues and 5 bladder cancer cell lines. Trans-well assay was used to detect the changes in migration and invasion abilities of bladder cancer T24 cells after TUG1 knockdown using RNA interference technique, and the alteration in the expression of CAPN7 was also detected. The expression of CAPN7 was examined in T24 cells overexpressing mir-29c-3p by Western blotting, and luciferase reporter assay was performed to confirm the targeting of miR-29c-3p to TUG1 and CAPN7. The effects of CAPN7 overexpression and sh-TUG1 on the migration and invasion of T24 cells were investigated.

RESULTS

The expression of TUG1 was up-regulated and mir-29c-3p was down-regulated significantly in bladder cancer tissue with a negative correlation between their expressions. TUG1 knockdown significantly inhibited the migration and invasion of T24 cells (P < 0.01). Overexpression of mir-29c-3p in T24 cells obviously down-regulated the expression of CAPN7 protein, whose expression was positively correlated with TUG1 expression (r=0.4081, P=0.0139). The results of luciferase reporter assay confirmed both TUG1 and CAPN7 as the targets of mir-29c-3p. CAPN7 overexpression could partially reverse the tumor suppressing effect of sh-TUG1 in T24 cells.

CONCLUSIONS

Mir-29c-3p targeting TUG1 affects the migration and invasion of bladder cancer cells by regulating the expression of CAPN7.

Pathophysiological Functions of the lncRNA TUG1

BACKGROUND

Long non-coding RNAs (lncRNAs) with little or no coding capacity are associated with a plethora of cellular functions, participating in various biological processes. Cumulative study of lncRNA provides explanations to the physiological and pathological processes and new perspectives to the diagnosis, prevention, and treatment of some clinical diseases. Long non-coding RNA taurine-upregulated gene 1(TUG1) is one of the first identified lncRNAs associated with human disease, which actively involved in various physiological processes, including regulating genes at epigenetics, transcription, post-transcription, translation, and posttranslation. The aim of this review was to explore the molecular mechanism of TUG1 in various types of human diseases.

METHODS

In this review, we summarized and analyzed the latest findings related to the physiologic and pathophysiological processes of TUG1 in human diseases. The related studies were retrieved and selected the last six years of research articles in PubMed with lncRNA and TUG1 as keywords.

RESULTS

TUG1 is a valuable lncRNA that its dysregulated expression and regulating the biological processes were found in a variety of human diseases. TUG1 is found to exhibit aberrant expression in a variety of malignancies. Dysregulation of TUG1 has been shown to contribute to proliferation, migration, cell cycle changes, inhibited apoptosis, and drug resistance of cancer cells, which revealed an oncogenic role for this lncRNA, but some reports have shown downregulation of TUG1 in lung cancer samples compared with noncancerous samples. In addition, the molecular and biological functions of TUG1 in physiology and disease (relevant to endocrinology, metabolism, immunology, neurobiology) have also been highlighted. Finally, we discuss the limitations and tremendous diagnostic/therapeutic potential of TUG1 in cancer and other diseases.

CONCLUSION

Long non-coding RNA-TUG1 likely served as useful disease biomarkers or therapy targets and effectively applied in different kinds of diseases, such as human cancer and cardiovascular diseases.

TUG1 enhances high glucose-impaired endothelial progenitor cell function via miR-29c-3p/PDGF-BB/Wnt signaling

BACKGROUND

Diabetes is associated with the dysfunction of endothelial progenitor cells (EPCs), characterized as impaired angiogenesis, a phenomenon thought to be involved in the development of diabetic foot. lncRNA plays an essential role in microvascular dysfunction and signaling pathways in patients with diabetes. lncRNA taurine upregulated gene 1 (TUG1) participates in angiogenesis in various cells. However, the mechanisms of TUG1 activity in EPCs have not been elucidated.

METHODS

We isolated and then characterized EPCs from the peripheral blood of mice using immunofluorescence and flow cytometry. Western blot detected the wnt/β-catenin pathway in high glucose-treated EPCs. Bioinformatics analysis predicted a putative binding site for TUG1 on miR-29c-3p. The interactions among TUG1, platelet-derived growth factor-BB (PDGF-BB), and miR-29c-3p were analyzed by luciferase assays. In vivo, diabetic mouse ischemic limb was treated with normal saline or TUG1 overexpression lentiviruses.

RESULTS

We found that EPC migration, invasion, and tube formation declined after treatment with high glucose, but improved with TUG1 overexpression. Mechanically, wnt/β-catenin pathway and autophagy were involved in the function of TUG1 overexpression in high glucose-treated EPCs. Moreover, TUG1 regulates the PDGF-BB/wnt pathway and function of high glucose-treated EPCs via miR-29c-3p. In vivo, injection of TUG1 lentivirus in a diabetic mouse ischemic limb model stimulated angiogenesis.

CONCLUSIONS

Our findings suggest that TUG1 restores high glucose-treated EPC function by regulating miR-29c-3p/PDGF-BB/Wnt signaling.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

LncRNA DDX11-AS1 Promotes Bladder Cancer Occurrence Via Protecting LAMB3 from Downregulation by Sponging miR-2355-5p

Background: As a subtype of human genitourinary system cancer, the morbidity of bladder cancer (BC) continues to rise. Because of the high potentiality of cell metastasis, the 5-year survival rate of BC is relatively low. Long noncoding RNAs (lncRNAs) have been verified by a large body of literature to engage in the tumorigenesis of a few cancers. DDX11-AS1 has been elucidated as a malignancy promoter in several cancers; therefore, its mysterious role in BC attracted our interest as being well worth investigating. Aim of the Study: The primary consideration of this article was to clarify the part that DDX11-AS1 plays in the progression of BC. Methods: The expression of DDX11-AS1 in BC was revealed by quantitative real-time polymerase chain reaction. The biological functions of DDX11-AS1 in BC were evaluated through CCK-8 (Cell Counting Kit-8), EDU, TUNEL (TdT-mediated dUTP nick-end labeling), flow cytometry analysis, and Western Blot assays. Luciferase or RNA immunoprecipitation assay was used to investigate the interaction between miR-2355-5p and DDX11-AS1 (or LAMB3). Results: DDX11-AS1 manifested remarkably high level in BC and promoted the malignancy of BC. Moreover, miR-2355-5p was validated to be able to bind with DDX11-AS1 and inhibit cell proliferation in BC. Furthermore, our data suggested that LAMB3 expression was evidently upregulated in BC cells and inversely modulated by miR-2355-5p. Besides, LAMB3 may bind with miR-2355-5p. Ultimately, rescue assays indicated that the restrained development of BC in sh-DDX11-AS1#1-transfected cells could be restored by enforced expression of LAMB3. Conclusion: DDX11-AS1 facilitates the tumorigenesis of BC by the miR-2355-5p/LAMB3 axis.

Exosomal taurine up-regulated 1 promotes angiogenesis and endothelial cell proliferation in cervical cancer

Emerging evidence had highlighted that exosomes could mediate cell-cell communication in human cancerous development via transferring the various molecular cargos, including long non-coding RNA (lncRNA). Taurine up-regulated 1 (TUG1) was previously reported as an oncogenic lncRNA in cervical cancer (CC) via facilitating cell proliferation and other vital biological behaviors. Nevertheless, the presence of TUG1 in exosomes and the functional regulation of exosomal TUG1 in CC are still elusive. The current study aimed at the communication between CC cell lines and endothelial cell-mediated by exosomes, as well as the roles of exosomes derived from CC cells and exosomal TUG1 in affecting angiogenesis. Initially, it was found that TUG1 expression was upregulated in both CC cells and their secreted exosomes. TUG1 was transferred from CC cells to recipient human umbilical vein endothelial cells (HUVECs) in the exosomes way. Interestingly, TUG1 depletion impaired the exosomes-mediated proangiogenic potential of HUVECs by modulating certain key angiogenesis-related genes. In addition, exosomal TUG1 contributed to HUVECs proliferation through suppressing caspase-3 activity and impacting apoptosis-related proteins. Collectively, we identified a new exosomes-mediated molecular mechanism by which CC cells transferred TUG1 via exosomes to recipient HUVECs, thus promoting angiogenesis, providing a promising target for early diagnosis of CC.

Epigenetics of Bladder Cancer: Where Biomarkers and Therapeutic Targets Meet

Bladder cancer (BC) is the most common neoplasia of the urothelial tract. Due to its high incidence, prevalence, recurrence and mortality, it remains an unsolved clinical and social problem. The treatment of BC is challenging and, although immunotherapies have revealed potential benefit in a percentage of patients, it remains mostly an incurable disease at its advanced state. Epigenetic alterations, including aberrant DNA methylation, altered chromatin remodeling and deregulated expression of non-coding RNAs are common events in BC and can be driver events in BC pathogenesis. Accordingly, these epigenetic alterations are now being used as potential biomarkers for these disorders and are being envisioned as potential therapeutic targets for the future management of BC. In this review, we summarize the recent findings in these emerging and exciting new aspects paving the way for future clinical treatment of this disease.

Long non-coding RNA NEAT1 promotes bladder progression through regulating miR-410 mediated HMGB1

LncRNA NEAT1 is reported as a crucial oncogene in multiple cancers. But, its biological role in bladder cancer is barely understood. Therefore, we concentrated on the function and role of NEAT1 in bladder cancer. Firstly, NEAT1 expression in bladder cancer cells was determined and it was displayed NEAT1 was significant elevated. NEAT1 was knockdown and overexpressed in T24 and J82 cells. Then it was indicated that NEAT1 silence greatly inhibited bladder cancer cell proliferation with an increased ratio of apoptotic cells and severe cell cycle arrest. Overexpression of NEAT1 exhibited a reversed process in bladder cancer cells. Additionally, in vivo experiments were employed using establishment of nude mice models. NEAT1 knockdown inhibited bladder cancer growth while increase of NEAT1 promoted bladder cancer development in vivo. By employing the bioinformatics analysis, we speculated that miR-410 was as a downstream target of NEAT1. Then, the targeting association between them was proved in our research and we implicated miR-410 was dramatically restrained in bladder cancer cells. Meanwhile, it was exhibited that miR-410 was negatively regulated by NEAT1. Apart from these, HMGB1 was speculated as a downstream target of miR-410. Dual-luciferase reporter assay was used to prove the correlation between miR-410 and HMGB1. Up-regulation of miR-410 restrained HMGB1 levels and NEAT1 can regulate HMGB1 level via sponging miR-410. To sum up, we implied NEAT1/miR-410/HMGB1 axis participated in bladder cancer.

Molecular mechanisms of TUG1 in the proliferation, apoptosis, migration and invasion of cancer cells

Long non-coding RNAs (lncRNAs) are RNA sequences >200 nucleotides in length that have no protein-coding capacity. lncRNAs serve key roles in multiple biological processes, such as tumorigenesis and tumor progression. Taurine upregulated 1 (TUG1) is a novel lncRNA that has been associated with human cancer. TUG1 has attracted increasing attention in recent years and has been documented to be abnormally expressed in different types of cancer. Numerous studies indicate that TUG1 may be significantly associated with tumor development and cell metabolism by regulating cell proliferation, invasion, metastasis, apoptosis, differentiation and drug resistance. TUG1 exerts its function via recruiting specific RNA-binding proteins, promoting target gene expression, influencing tumor angiogenesis and by functioning as a competing endogenous RNA (ceRNA). An increasing number of studies have demonstrated that ceRNAs serve a role in cancer development. TUG1 is considered to be a biomarker or a novel therapeutic target for the diagnosis and prognosis of different cancer types. The present review focuses on recent developments in the major underlying molecular mechanisms of TUG1 in cancer, including its role in cell proliferation, apoptosis, migration, invasion and drug resistance. Also discussed in the present review is the current knowledge regarding the regulation of TUG1.

Correlation of long non-coding RNA taurine-upregulated gene 1 with disease conditions and prognosis, as well as its effect on cell activities in acute myeloid leukemia

OBJECTIVE

This study aimed to investigate the correlation of long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) with clinicopathological characteristics and prognosis in acute myeloid leukemia (AML) patients, as well as its function in cell proliferation and apoptosis.

METHODS

Two hundred and thirty six de novo AML patients were consecutively enrolled and then underwent conventional induction chemotherapy. Bone marrow samples were obtained from all AML patients and controls. Quantitative polymerase chain reaction assay was performed to detect lncRNA TUG1 expression. KG-1 cells were transfected by TUG1 inhibitor (TUG1 (-)) and blank inhibitor (NC (-)) plasmids. Cell proliferation and apoptosis were evaluated by CCK8 and AV/PI assays, and apoptotic markers expressions were detected by Western blot assay.

RESULTS

LncRNA TUG1 expression was higher in AML patients compared to controls, and it was positively correlated with white blood cell counts as well as poor risk stratification. Additionally, elevated lncRNA TUG1 expression was observed in non-complete remission (non-CR) patients compared to CR patients, and it was correlated with shorter event-free survival and overall survival in AML patients. In the in vitro experiments, lncRNA TUG1 expression was upregulated in AML cell lines compared to control cells, and cell proliferation ability was reduced, but cell apoptosis rate was promoted in TUG1 (-) group compared to NC (-) group at 72 hours after transfection in KG-1 cells.

CONCLUSIONS

LncRNA TUG1 predicts advanced disease conditions and poor prognosis in AML patients, and its knockout decreases proliferation and increases apoptosis of AML cells.

Taurine-upregulated gene 1: A functional long noncoding RNA in tumorigenesis

Taurine-upregulated gene 1 (TUG1) is a 7.1 kb long noncoding RNA (lncRNA) first recognized in 2005 as an important element for retinal development in rodents. Subsequently, this lncRNA has been shown to participate in oncogenic processes through alteration in chromatin structure, sponging microRNAs, and affecting the expression of some cancer-related pathways. While most of the studies have revealed an oncogenic role for this lncRNA, some reports have shown downregulation of TUG1 in lung cancer samples compared with noncancerous samples. In triple negative breast cancer samples, the expression of this lncRNA has been decreased. Besides, its expression has been higher in HER2-enriched and basal-like subtypes compared with luminal A. In the current review, we discuss the latest literature about the expression pattern and functional roles of TUG1 in diverse cancer types. In addition, its role in epithelial-mesenchymal transition and activation of Wnt/β-catenin pathway in human malignancies will be explored.

Taurine-upregulated gene 1 contributes to cancers through sponging microRNA

Long non-coding RNAs (lncRNAs) are a class of RNAs whose transcripts are more than 200 nucleotides in length and lack protein-coding ability. Taurine-upregulated gene 1 (TUG1), a novel cancer-related lncRNA, has been documented to be abnormally expressed in various types of cancers and act as an oncogene or anti-oncogene. It has been considered previously that TUG1 is closely related to the cell proliferation, invasion, metastasis, and apoptosis of cancer. In recent years, it has been found that TUG1 acts as a microRNA (miRNA) sponge to indirectly regulate the expression of the miRNA target gene and dominates cancer progression in several types of cancers. However, TUG1 also binds to different miRNAs to produce diverse regulatory mechanisms in the same cancer. TUG1 is expected to be a biomarker and a new therapeutic target for the diagnosis and prognosis of certain cancers. In this review, we highlight the up-to-date original studies that focus on the role of TUG1 sponging miRNA in cancers and summarize the function of TUG1 in cancer progression. The novel TUG1-miRNA regulatory network is comprehensively and minutely included in this review. We hope that this review will help readers obtain a more detailed knowledge of the molecular mechanism by which TUG1 sponging miRNA plays its role in cancers, and provide some insights and directions for future cancer research.

High LINC01605 expression predicts poor prognosis and promotes tumor progression via up-regulation of MMP9 in bladder cancer

The advent of high-throughput sequencing methods has facilitated identification of novel long non-coding RNAs (lncRNAs), which have been demonstrated to play an important role in multiple tumors. Moreover, with the assistance of bioinformatics analysis, LINC01605 has been found to be up-regulated in bladder cancer (BC) tissues compared with normal tissues. Hence, the present study was to explore its specific biological role and related mechanism in BC. The relative expression level of LINC01605 was measured in a cohort of BC tissues with matched normal tissues as well as human BC cell lines by quantitative real-time PCR (qRT-PCR). Survival analysis was performed to explore the relationship between LINC01605 expression and the prognosis of BC patients. The biological function of LINC01605 was studied in vitroand in vivo, by means of CCK-8 assay, colony formation assay, transwell assay, and tumor xenografts mice model. LINC01605 was found to be frequently highly expressed in both human BC cells and tissues. Survival analysis indicated that high LINC01605 expression was associated with higher histological grade and clinical stages. In addition, down-regulated LINC01605 in BC cells could significantly inhibit the abilities of proliferation, migration, and invasion in vitro and knockdown of LINC01605 in subcutaneous xenograft tumor model could impede tumorigenesis in vivo. Mechanistically, LINC01605 could activate epithelial–mesenchymal transition (EMT) signaling pathway and promote the expression of matrix metallopeptidase (MMP) 9 (MMP9). In summary, our results shed light on that LINC01605, as a new prognostic biomarker, could promote the proliferation, migration, and invasion of BC cells via activating EMT signaling pathway and up-regulating MMP9 expression.

Long non-coding RNA TUG1 sponges miR-197 to enhance cisplatin sensitivity in triple negative breast cancer

Breast cancer is the leading cause of women death worldwide. Several long non-coding RNAs (lncRNAs) have been identified as oncogenes or tumor suppressors during the progression of cancers. However, the role of taurine upregulated gene (TUG1) in mediating the chemotherapy sensitivity of triple negative breast cancer (TNBC) has not been studied yet. In TNBC patients, we observed a significant decrease of TUG1 in tumor tissues compared to the normal tissues. Similarly, TUG1 expression was significantly decreased in TNBC cell lines compared with normal breast epithelial cell line and cell lines of other subtypes of breast cancer. In MDA-MB-231 and BT549, cisplatin induced cell growth arrest was remarkably augmented by overexpression of TUG1 and was significantly reduced by TUG1 silencing. Moreover, very low concentration of cisplatin caused cell proliferation inhibition in TUG1-overexpressed-TNBC cells. In addition, we found that TUG1 negatively regulated miR-197 expression in the tested TNBC cell lines. Sponging of TUG1 to miR-197 was proved by a dual luciferase reporter assay. We further predicted and validated that nemo-like kinase (NLK), which was positively controlled by TUG1, was a target gene of miR-197. Via regulation of miR-197/NLK, TUG1 inactivated WNT signaling pathway and thus increasing chemotherapy sensitivity of TNBC cells. Analysis of TCGA database showed that higher expression of TUG1 was associated with better prognosis in breast cancer patients. Our current study drew a preliminary conclusion that TUG1 was involved in chemotherapy sensitivity in TNBC cells.

Long non-coding RNA taurine-upregulated gene 1 correlates with poor prognosis, induces cell proliferation, and represses cell apoptosis via targeting aurora kinase A in adult acute myeloid leukemia

This study aimed to investigate the correlation of long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) with clinicopathological feature and prognosis, and to explore its effect on cell proliferation and apoptosis as well as the relevant target genes in adult acute myeloid leukemia (AML). LncRNA TUG1 expression was detected in bone marrow samples from 186 AML patients and 62 controls. Blank mimic, lncRNA TUG1 mimic, blank inhibitor, and lncRNA TUG1 inhibitor lentivirus vectors were transfected in KG-1 cells. Rescue experiment was performed by transfection of lncRNA TUG1 inhibitor and aurora kinase A (AURKA) mimic lentivirus vectors. Cell proliferation, apoptosis, RNA, and protein expressions were determined by CKK-8, annexin V-FITC-propidium iodide, quantitative polymerase chain reaction, and western blot assays. LncRNA TUG1 expression was higher in AML patients compared to controls and correlated with higher white blood cell counts, monosomal karyotype, FLT3-ITD mutation, poor-risk stratification, and poor prognosis, which independently predicted worse event-free survival and overall survival. In vitro, lncRNA TUG1 expression was higher in AML cell lines (KG-1, MOLM-14, HL-60, NB-4, and THP-1 cells) compared to controls. LncRNA TUG1 mimic promoted cell proliferation and decreased cell apoptosis rate, while lncRNA TUG1 inhibitor repressed cell proliferation and increased cell apoptosis rate. Rescue experiment showed that AURKA attenuated the influence of lncRNA TUG1 on AML cell proliferation and apoptosis. In conclusion, lncRNA TUG1 associates with advanced disease and worse prognosis in adult AML patients, and it induces AML cell proliferation and represses cell apoptosis via targeting AURKA.