Long non-coding RNA TUG1 regulates ovarian cancer proliferation and metastasis via affecting epithelial-mesenchymal transition

DNA Methylation of a Group of Long Non-Coding RNA Genes at Different Stages of Ovarian Cancer Dissemination

There are three types of metastases in ovarian cancer: lymphogenous, hematogenous, and peritoneal. Dissemination of the tumor in the peritoneum is directly related with the development of ascites and a poor prognosis. The purpose of this study is to determine changes in the methylation level of a group of long non-coding RNA (lncRNA) genes at different stages of ovarian cancer progression. The methylation level of 7 lncRNA genes (LINC00472, LINC00886, MAFG-DT, SNHG1, SNHG6, TP53TG1, and TUG1) was studied by quantitative methyl-specific PCR in 93 samples of ovarian tumors and 75 paired samples of histologically normal tissue, as well as in 29 peritoneal macroscopic metastases. Using the nonparametric Mann-Whitney test, a significant (p<0.001) increase in the level of methylation of the LINC00886, SNHG1, SNHG6, and TUG1 genes in the tumor tissue was shown. For the LINC00472, LINC00886, and SNHG6 genes, a significant relationship was found with the clinical stage (p≤0.001), as well as with the appearance of metastases for the LINC00472 (p<0.001) and SNHG6 (p=0.005) genes. There was a significant increase in the level of methylation of MAFG-DT and TP53TG1 (p<0.001) genes, as well as a decrease in LINC00886 (p=0.003) in peritoneal metastases relative to the primary focus. Methylation of the LINC00472 and SNHG6 genes can be considered as a factor in initiating ovarian cancer metastasis, and methylation of the LINC00886, MAFG-DT, and TP53TG1 genes as a colonization factor for metastases in the peritoneum. Thus, a relationship between methylation of a group of lncRNA genes at different stages of ovarian cancer dissemination was shown, which is important for understanding the mechanisms of these processes and for developing innovative approaches to ovarian cancer therapy.

The Role of Long Noncoding RNAs in Progression of Leukemia: Based on Chromosomal Location

Long non-coding RNA [LncRNA] dysregulation has been seen in many human cancers, including several kinds of leukemia, which is still a fatal disease with a poor prognosis. LncRNAs have been demonstrated to function as tumor suppressors or oncogenes in leukemia. This study covers current research findings on the role of lncRNAs in the prognosis and diagnosis of leukemia. Based on recent results, several lncRNAs are emerging as biomarkers for the prognosis, diagnosis, and even treatment outcome prediction of leukemia and have been shown to play critical roles in controlling leukemia cell activities, such as proliferation, cell death, metastasis, and drug resistance. As a result, lncRNA profiles may have superior predictive and diagnostic potential in leukemia. Accordingly, this review concentrates on the significance of lncRNAs in leukemia progression based on their chromosomal position.

Long Non-Coding RNAs: Bridging Cancer-Associated Thrombosis and Clinical Outcome of Ovarian Cancer Patients

Ovarian cancer (OC) and venous thromboembolism (VTE) have a close relationship, in which tumour cells surpass the haemostatic system to drive cancer progression. Long non-coding RNAs (lncRNAs) have been implicated in VTE pathogenesis, yet their roles in cancer-associated thrombosis (CAT) and their prognostic value are unexplored. Understanding how these lncRNAs influence venous thrombogenesis and ovarian tumorigenesis may lead to the identification of valuable biomarkers for VTE and OC management. Thus, this study evaluated the impact of five lncRNAs, namely MALAT1, TUG1, NEAT1, XIST and MEG8, on a cohort of 40 OC patients. Patients who developed VTE after OC diagnosis had worse overall survival compared to their counterparts (log-rank test, p = 0.028). Elevated pre-chemotherapy MEG8 levels in peripheral blood cells (PBCs) predicted VTE after OC diagnosis (Mann-Whitney U test, p = 0.037; Χ2 test, p = 0.033). In opposition, its low levels were linked to a higher risk of OC progression (adjusted hazard ratio (aHR) = 3.00; p = 0.039). Furthermore, low pre-chemotherapy NEAT1 levels in PBCs were associated with a higher risk of death (aHR = 6.25; p = 0.008). As for the remaining lncRNAs, no significant association with VTE incidence, OC progression or related mortality was observed. Future investigation with external validation in larger cohorts is needed to dissect the implications of the evaluated lncRNAs in OC patients.

Long Non-Coding RNAs and microRNAs Groups in the Regulation of Expression Level of a Number of Tumor-Associated Genes in Ovarian Cancer

The search for interacting long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs of protein-coding genes through the mechanism of competing endogenous RNAs in tumors of ovarian cancer patients was carried out. The levels of expression of 24 lncRNAs, 20 miRNAs, and 28 mRNAs of protein-coding genes involved in oncogenesis were determined by real-time PCR on a set of representative samples. Correlations between lncRNAs/miRNA and miRNA/mRNA levels in ovarian cancer samples were analyzed. We identified 8 pairs of lncRNAs/miRNA and 17 pairs of miRNA/mRNA, the expression levels of which have a negative correlation. Five triplets of potentially interacting lncRNAs/miRNA/mRNA have been identified, among which the most significant triplet is the OIP5-AS1/miR-203a-3p/ZEB1. The data obtained determine new epigenetic profiles, as well as new potential biomarkers and targets for targeted therapy of ovarian cancer patients.

LncRNA TUG1 promotes the migration and invasion in type I endometrial carcinoma cells by regulating E-N cadherin switch

OBJECTIVE

Accumulating evidence has demonstrated that lncRNA Taurine-upregulated gene 1 (TUG1) plays an important role in regulation of cell morphology, migration, proliferation and apoptosis. Our aim was to evaluate the oncogenic role of TUG1 in type I Endometrial Carcinoma (EC) and explore the precise mechanism of TUG1 involved in tumor progression.

MATERIALS AND METHODS

The GSE17025 data set was used to analyze the correlation of TUG1 expression with type I EC patients' prognosis. Furthermore, TUG1 expression profiles were measured by qRT-PCR from carcinoma tissues and adjacent nonneoplastic tissues (NNT) of 105 type I EC patients. The regulation of epithelial-mesenchymal transition (EMT) related molecules, p-AKT and AKT by TUG1 knockdown was investigated using Western blot analysis; meanwhile, the oncogenic roles of TUG1 were evaluated using cell viability and transwell migration/invasion assay in Hec-1-A and Ishikawa cell lines.

RESULTS

Firstly, we observed a significant association between higher TUG1 expression and lower survival rate in type I EC patients using the GSE17025 data set. A significant elevation of TUG1 levels was confirmed in type I EC tissues compared with NNT in the 105 type I EC patients, and high expression of TUG1 was associated with lymph vascular space invasion (LVSI) and lymph node metastasis (LNM). Subsequently, TUG1 knockdown could remarkably inhibit the Hec-1-A and Ishikawa cell invasion and migration in the functional experiment. Furthermore, our results showed that the protein levels of E-cadherin increased and N-cadherin decreased significantly, while β-catenin and Vimentin were not significantly altered upon TUG1 silencing in both Hec-1-A and Ishikawa cells. Finally, we found the p-AKT and AKT protein levels, and the rate of p-AKT/t-AKT has a tendency to be down-regulate in Hec-1-A cells, while the AKT pathway was not change significantly in Ishikawa cells after TUG1 knockdown.

CONCLUSION

Collectively, our data reveal that TUG1 might be regarded as an oncogenic molecule that promotes type I EC cells metastasis leading to tumor progression, at least partially, by regulating E-N cadherin switch and the AKT pathway.

Repression of lncRNA PART1 attenuates ovarian cancer cell viability, migration and invasion through the miR-503-5p/FOXK1 axis

BACKGROUND

Ovarian cancer (OC) is a female malignant tumor with a high fatality rate. Long non-coding RNAs (lncRNAs) are deeply involved in OC progression. The aim of this study is to explore the specific mechanism of lncRNA prostate androgen-regulated transcript 1 (PART1) in OC.

METHODS

Quantitative real time PCR was utilized to determine the expression levels of PART1, microRNA (miR)-503-5p and forkhead-box k1 (FOXK1) in OC tissues and/or cells. The cell viability, migration, and invasion in OC were evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-h-tetrazolium bromide assay, wound healing assay and transwell invasion assay, respectively. Flow cytometry was used to analyze the cell apoptosis. The xenograft tumor was conducted in nude mice to verify the effect of PART1 knockdown on OC in vivo. The target relationships among PART1, miR-503-5p and FOXK1 were predicted by StarBase, and verified by luciferase reporter assay. The level of FOXK1 was assessed by western blot.

RESULTS

Increased expression of PART1 and FOXK1 was observed in OC tissues or cells, whereas miR-503-5p was downregulated. PART1 silencing or miR-503-5p overexpression repressed the cell viability, migration and invasion, and protomed apoptosis. Meanwhile, miR-503-5p was a target of PART1, and FOXK1 was a direct target gene of miR-503-5p. Both downregulation of miR-503-5p and upregulation of FOXK1 partly relieved the suppressive effects of PART1 knockdown on the oncogenicity of OC in vitro.

CONCLUSION

Decreased PART1 represses the cell viability, migration and invasion of OC via regulating the miR-503-5p/FOXK1 axis, which provided an underlying target for treating OC.

LPI-EnEDT: an ensemble framework with extra tree and decision tree classifiers for imbalanced lncRNA-protein interaction data classification

BACKGROUND

Long noncoding RNAs (lncRNAs) have dense linkages with various biological processes. Identifying interacting lncRNA-protein pairs contributes to understand the functions and mechanisms of lncRNAs. Wet experiments are costly and time-consuming. Most computational methods failed to observe the imbalanced characterize of lncRNA-protein interaction (LPI) data. More importantly, they were measured based on a unique dataset, which produced the prediction bias.

RESULTS

In this study, we develop an Ensemble framework (LPI-EnEDT) with Extra tree and Decision Tree classifiers to implement imbalanced LPI data classification. First, five LPI datasets are arranged. Second, lncRNAs and proteins are separately characterized based on Pyfeat and BioTriangle and concatenated as a vector to represent each lncRNA-protein pair. Finally, an ensemble framework with Extra tree and decision tree classifiers is developed to classify unlabeled lncRNA-protein pairs. The comparative experiments demonstrate that LPI-EnEDT outperforms four classical LPI prediction methods (LPI-BLS, LPI-CatBoost, LPI-SKF, and PLIPCOM) under cross validations on lncRNAs, proteins, and LPIs. The average AUC values on the five datasets are 0.8480, 0,7078, and 0.9066 under the three cross validations, respectively. The average AUPRs are 0.8175, 0.7265, and 0.8882, respectively. Case analyses suggest that there are underlying associations between HOTTIP and Q9Y6M1, NRON and Q15717.

CONCLUSIONS

Fusing diverse biological features of lncRNAs and proteins and exploiting an ensemble learning model with Extra tree and decision tree classifiers, this work focus on imbalanced LPI data classification as well as interaction information inference for a new lncRNA (or protein).

Long non-coding RNA TUG1 promotes proliferation and migration in PDGF-BB-stimulated HASMCs by regulating miR-216a-3p/SMURF2 axis

BACKGROUND

Abnormal proliferation and migration of human airway smooth muscle cells (HASMCs) play an important role in the development of childhood asthma. Long non-coding RNAs (lncRNAs) have been demonstrated to participate in HASMC proliferation and migration. We aimed to explore more effects and molecular mechanism of taurine upregulated gene 1 (TUG1) in childhood asthma.

RESULTS

TUG1 and SMURF2 were overexpressed and miR-216a-3p was downregulated in childhood asthma patients and PDGF-BB-stimulated HASMCs. TUG1 knockdown attenuated PDGF-BB-triggered proliferation and migration of HASMCs. MiR-216a-3p was targeted by TUG1, and miR-216a-3p suppression counteracted the repressive effects of TUG1 interference on proliferation and migration in PDGF-BB-treated HASMCs. SMURF2 was a downstream target of miR-216a-3p, and SMURF2 upregulation abated the inhibiting effects of miR-216a-3p on migration and proliferation in PDGF-BB-exposed HASMCs. TUG1 sponged miR-216a-3p to positively regulate SMURF2 expression.

CONCLUSION

TUG1 downregulation inhibited PDGF-BB-induced HASMC proliferation and migration by regulating miR-216a-3p/SMURF2 axis, offering novel insight into the potential application of TUG1 for childhood asthma treatment.

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.

Long non-coding RNAs: A view to kill ovarian cancer

An emerging role of long non-coding RNAs (lncRNAs) in tumor progression has been revealed in the last decade. Through interactions with nucleic acids and proteins, lncRNAs could act as enhancers, scaffolds or decoys for a number of oncoproteins and tumor suppressors. The aberrant lncRNA expression or mutations are often associated with changes in a variety of cellular processes, including proliferation, stress response and cell death. Here, we will focus on the tumor-associated lncRNAs in ovarian cancer according to their contribution to cancer hallmarks, such as intense proliferation, cell death resistance, altered energy metabolism, invasion and metastasis, and immune evasion. Moreover, the potential clinical implications of lncRNAs and their significance for the diagnosis, prognosis and therapy of ovarian cancer will be discussed.

Long non-coding RNA LINC01215 promotes epithelial-mesenchymal transition and lymph node metastasis in epithelial ovarian cancer through RUNX3 promoter methylation

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The study first reports the regulation of LINC01215 on methylation of RUNX3 promoter.

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LINC01215 is highly expressed while RUNX3 is reciprocal in EOC.

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LINC01215 overexpression promotes methylation of RUNX3 and reduces its expression.

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LINC01215 silencing suppresses LNM and EMT of EOC.

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This study may provide a new therapeutic target for EOC.

Epithelial ovarian cancer (EOC) still remains the most lethal gynaecological malignancy in women, despite the recent progress in the management, including surgery and chemotherapy. According to the microarray data of the GSE18520 and GSE54388 datasets, LINC01215 was identified as an upregulated long noncoding RNA (lncRNA) in EOC. Therefore, this study aimed to figure out the involvement of LINC01215 in the progression of EOC. RT-qPCR was conducted to select the EOC cell line with the highest expression of LINC01215. Methylation of RUNX3 was then examined in EOC cells by MS-PCR. Furthermore, the interaction between LINC01215 and methylation-related proteins was revealed according to the results of RIP and RNA pull down assays. Subsequently, the involvement of LINC01215 and RUNX3 in regulating biological behaviors of EOC cells was investigated. Finally, the effects of the ectopic expression of LINC01215 and RUNX3 on the tumor formation and lymph node metastasis (LNM) of EOC cells were assessed in the xenograft tumors of nude mice. Overexpressing LINC01215 contributed to downregulated levels of RUNX3, as demonstrated by the recruitment of methylation-related proteins. Silencing of LINC01215 elevated the expression of RUNX3, thus suppressing cell proliferation, migration, invasion and EMT and decreasing the expressions of MMP-2, MMP-9 and Vimentin, but increased the expression of E-cadherin. The tumor growth and LNM were suppressed by downregulated levels of LINC01215 through inducing the expression of RUNX3. Collectively, the down-regulating LINC01215 could upregulate the expression of RUNX3 by promoting its methylation, thus suppressing EOC cell proliferation, migration and invasion, EMT, tumor growth and LNM.

Non-Coding RNAs as Biomarkers of Tumor Progression and Metastatic Spread in Epithelial Ovarian Cancer

Simple Summary

Despite advances in cancer research in recent years, efficient predictive biomarkers of tumor progression and metastatic spread for ovarian cancer are still missing. Therefore, we critically address recent findings in the field of non-coding RNAs (microRNAs and long non-coding RNAs) and DNA methylation in ovarian cancer patients as promising novel biomarkers of ovarian cancer progression.

Abstract

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.

The Involvement of Long Non-Coding RNAs in Bone

A harmonious balance between osteoblast and osteoclast activity guarantees optimal bone formation and resorption, pathological conditions affecting the bone may arise. In recent years, emerging evidence has shown that epigenetic mechanisms play an important role during osteoblastogenesis and osteoclastogenesis processes, including long non-coding RNAs (lncRNAs). These molecules are a class of ncRNAs with lengths exceeding 200 nucleotides not translated into protein, that have attracted the attention of the scientific community as potential biomarkers to use for the future development of novel diagnostic and therapeutic approaches for several pathologies, including bone diseases. This review aims to provide an overview of the lncRNAs and their possible molecular mechanisms in the osteoblastogenesis and osteoclastogenesis processes. The deregulation of their expression profiles in common diseases associated with an altered bone turnover is also described. In perspective, lncRNAs could be considered potential innovative molecular biomarkers to help with earlier diagnosis of bone metabolism-related disorders and for the development of new therapeutic strategies.

Multi-Label Fusion Collaborative Matrix Factorization for Predicting LncRNA-Disease Associations

As we all know, science and technology are developing faster and faster. Many experts and scholars have demonstrated that human diseases are related to lncRNA, but only a few associations have been confirmed, and many unknown associations need to be found. In the process of finding associations, it takes a lot of time, so finding an efficient way to predict the associations between lncRNAs and diseases is particularly important. In this paper, we propose a multi-label fusion collaborative matrix factorization (MLFCMF) approach for predicting lncRNA-disease associations (LDAs). Firstly, the lncRNA space and disease space are optimized by multi-label to enhance the intrinsic link between lncRNA and disease and to tap potential information. Multi-label learning can encode a variety of data information from the sample space. Secondly, to learn multi-label information in the data space, the fusion method is used to handle the relationship between multiple labels. More comprehensive information will be obtained by weighing the effects of different labels. The addition of Gaussian interaction profile (GIP) kernel can increase the network similarity. Finally, the lncRNA-disease associations are predicted by the method of collaborative matrix factorization. The ten-fold cross-validation method is used to evaluate the MLFCMF method, and our method finally obtains an AUC value of 0.8612. Detailed analysis of ovarian cancer, colorectal cancer, and lung cancer in the simulation experiment results. So it can be seen that our method MLFCMF is an effective model for predicting lncRNA-disease associations.

LncRNA TUG1 facilitates proliferation, invasion and stemness of ovarian cancer cell via miR-186-5p/ZEB1 axis

LncRNA TUG1 has been rarely studied in ovarian cancer (OC), our objective was to explore the role of TUG1 in the regulation of malignant phenotypes of OC. Vectors of sh-TUG1, miR-186-5p and pcDNA-ZEB1 were, respectively, constructed and used to infect OC cells. MTT and transwell assays were applied for representing cell proliferation and invasion, respectively. Sphere formation experiment was used to detect the stemness of OC cells. Western blotting and qRT-PCR were employed for detecting the expression of multiple biomarkers on protein and RNA levels, respectively. The luciferase assay was performed to reveal the interactions between miR-186-5p and TUG1 or ZEB1. The silencing of TUG1 and upregulation of miR-186-5p both suppressed the cell proliferation, invasion and cancer stem cell (CSC) properties. Additionally, luciferase assay verified that miR-186-5p directly binds TUG1 and ZEB1. Moreover, overexpression of ZEB1 rescued the impact on the proliferation, invasion and stemness of TUG1 silencing in OC. TUG1 sponges miR-186-5p to release ZEB1 and promotes the proliferation, invasion and stemness of OC cells, suggesting that TUG1 could be a potential therapeutic target for OC therapy. SIGNIFICANCE OF THE STUDY: LncRNA TUG1 could promote proliferation, invasion and stemness of ovarian cancer cells. Our study first discovered that TUG1 play a tumourigenic role in ovarian cancer by regulating stemness of cancer cells. Mechanism research exhibited the regulation role of TUG1 in ovarian cancer cells was miR-186-5p/ZEB1 axis depended. These results provided a new perspective to understand the pathogenesis and development of ovarian cancer; it will offer new evidence for better diagnosis and treatment therapy of ovarian cancer.

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.

Long non-coding RNA TUSC7 suppresses osteosarcoma by targeting miR-211

Long non-coding RNAs (lncRNAs) play a critical role in regulating cancer progression and metastasis. LncRNA tumor suppressor candidate 7 (TUSC-7) was shown to be a tumor suppressor in osteosarcoma. However, the regulation mechanism of TUSC-7 in osteosarcoma is unknown. Bioinformatics analysis showed that TUSC7 specifically binds to miR-211. MiR-211 was up-regulated in osteosarcoma and negatively correlated with the expression of TUSC7. miR-211 expression was inhibited remarkably by TUSC7 overexpression and the reciprocal inhibition exists between TUSC7 and miR-211. RNA pull-down and luciferase reporter assays were used to validate the sequence-specific correlation between miR-211 and TUSC7. TUSC7 inhibited the proliferation, migration of osteosarcoma cells and promoted cellular apoptosis, which is largely mediated by miR-211. We conclude that the TUSC7 acted as a tumor suppressor gene, which is negatively regulated by miR-211. Our study could suggest a potentially novel therapeutic strategy against osteosarcoma.

Tissue-based long non-coding RNAs "PVT1, TUG1 and MEG3" signature predicts Cisplatin resistance in ovarian Cancer

OBJECTIVES

The current study aimed to investigate the potentiality of three lncRNAs "Plasmacytoma variant translocation 1(lnc-PVT1), Taurine upregulated gene type 1(lnc-TUG1) and Maternally expressed gene 3 (lnc-MEG-3)", to predict Cisplatin resistance in ovarian cancer (OC), in addition, to access their prognostic significance.

METHODS

The expression level of lncRNAs were measured in 100 formalin-fixed paraffin-embedded tissue (FFET) samples of OC patients who were treated by Cisplatin-based chemotherapy using qPCR.

RESULTS

The results showed that lnc_PVT1 was significantly upregulated by 2.3 folds in Cisplatin resistant tissues, while, lnc-TUG1 and lnc-MEG3 were downregulated by 1.2 and 3 folds, respectively. In addition, the three lncRNAs exhibited high sensitivity and specificity in predicting chemo-resistance and they were negatively associated with OS and progression-free survival (p < 0.001).

CONCLUSION

The lnc-PVT1, lnc-TUG1, and lnc-MEG3 transcriptome signatures could be used for predicting resistance to Cisplatin in OC patients.

miR‑1299/NOTCH3/TUG1 feedback loop contributes to the malignant proliferation of ovarian cancer

Recent studies have revealed the oncogenic role of notch reporter 3 (NOTCH3) in ovarian cancer (OC). However, the possible regulators and mechanisms underlying notch receptor 3 (NOTCH3)‑mediated behaviors in OC remain to be completely investigated. In the present study, we aimed to identify regulators of NOTCH3 and their interactions underlying the pathogenesis of OC. Bioinformatics analysis and luciferase reporter assay were used to identify potential regulatory miRNAs and lncRNAs of NOTCH3 in OC. Several in vivo and in vitro assays were performed to evaluate their effects on the proliferative ability mediated by NOTCH3. We identified microRNA‑1299 (miR‑1299) as a novel negative regulator of NOTCH3. miR‑1299 was downregulated in OC and was found to be considerably correlated with tumor differentiation. Upregulation of miR‑1299 inhibited cell proliferation, colony formation, and 5‑ethynyl‑2'‑deoxyuridine (EdU) incorporation, as well as induced cell cycle arrest in the G0G1 phase in OC cells. Overexpression of miR‑1299 in xenograft mouse models suppressed tumor growth in vivo. The lncRNA taurine upregulated gene 1 (TUG1), acting as a sponge of miR‑1299, was found to upregulate NOTCH3 expression and promote cell proliferation in OC through the competing endogenous RNA mechanism. In addition, TUG1 was found to be a potential downstream target of NOTCH3, forming a miR‑1299/NOTCH3/TUG1 feedback loop in the development of OC. Collectively, our findings improve the understanding of NOTCH3‑mediated regulation in OC pathogenesis and facilitate the development of miRNA‑ and lncRNA‑directed diagnostics and therapeutics against this disease.

Long Non-Coding RNA Taurine Upregulated Gene 1 (TUG1) Downregulation Constrains Cell Proliferation and Invasion through Regulating Cell Division Cycle 42 (CDC42) Expression Via MiR-498 in Esophageal Squamous Cell Carcinoma Cells

Background

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor of the gastrointestinal tract. Taurine upregulated gene 1 (TUG1), a long non-coding (lnc) RNA, also known as LIN00080 or TI-227H, was connected with the tumorigenesis of various diseases. Hence, we plumed the role and molecular mechanism of TUG1 in the progression of ESCC.

Material/Methods

Expression patterns of TUG1, microRNA-498 (miR-498), and cell division cycle 42 (CDC42) mRNA were assessed using quantitative real time polymerase chain reaction (qRT-PCR). The expression level of CDC42 protein was evaluated via western blot analysis. Cell proliferation and invasion were determined with Cell Counting Kit-8 (CCK-8) assay or Transwell assay. The relationship between miR-498 and TUG1 or CDC42 was predicted by online bioinformatics database LncBase Predicted v.2 or microT-CDS and confirmed through dual-luciferase reporter system or RNA immunoprecipitation assay (RIP).

Results

TUG1 and CDC42 were upregulated while miR-498 was strikingly decreased in ESCC tissues and cells (P<0.0001). Besides, TUG1 suppression blocked the proliferation and invasion of ESCC cells (P<0.001). Importantly, TUG1 decrease restrained CDC42 expression via binding to miR-498 in ESCC cells. Also, the suppressive impacts of TUG1 silencing on the proliferation and invasion of ESCC cells were mitigated by miR-498 reduction. Meanwhile, the repression of proliferation and invasion induced by miR-498 elevation was weakened by CDC42 overexpression.

Conclusions

Inhibition of TUG1 hampered cell proliferation and invasion by downregulating CDC42 via upregulating miR-498 in ESCC cells. Thus, TUG1 might be an underlying therapeutic target for ESCC.

Long Noncoding RNA TUG1 Promotes Autophagy-Associated Paclitaxel Resistance by Sponging miR-29b-3p in Ovarian Cancer Cells

Purpose

Paclitaxel (PTX) is a first-line chemotherapeutic agent for treating ovarian cancer. However, PTX resistance has become a major obstacle in ovarian cancer therapy. The underlying mechanism associated with PTX resistance is still unclear.

Patients and Methods

We used qPCR to detect taurine up-regulated 1 (TUG1) expression in normal ovarian tissues and ovarian tumor tissues. A combination of small interfering RNA (siRNA), cell counting kit 8 (CCK8), colony formation assay and nude mouse model were used to detect the effect of TUG1 on ovarian cancer cell PTX-resistance. Autophagy/cytotoxicity dual staining assay, luciferase reporter assay, Western blot and RNA-binding protein immunoprecipitation assay were used for further mechanistic studies.

Results

TUG1 is highly expressed not only in ovarian tumor tissues compared with normal ovarian tissues but also in the chemo-resistant group compared with the sensitive group. Knockdown of TUG1 by siRNA decreased ovarian cancer cell and xenograft tumor PTX resistance with or without PTX treatment. Moreover, deletion of TUG1 in ovarian cancer cells decreased autophagosome formation and increased apoptosis as demonstrated by autophagy/cytotoxicity dual staining and Western blot assays. Furthermore, microRNA-29b-3p (miR-29b-3p) was found as the direct target of TUG1. Additionally, TUG1 could directly bind Ago2, a key protein of the RNA-induced silencing complex.

Conclusion

Our findings suggest that TUG1, through targeting miR-29b-3p, induces autophagy and consequently results in PTX resistance in ovarian cancer.

Deciphering the Mounting Complexity of the p53 Regulatory Network in Correlation to Long Non-Coding RNAs (lncRNAs) in Ovarian Cancer

Amongst the various gynecological malignancies affecting female health globally, ovarian cancer is one of the predominant and lethal among all. The identification and functional characterization of long non-coding RNAs (lncRNAs) are made possible with the advent of RNA-seq and the advancement of computational logarithm in understanding human disease biology. LncRNAs can interact with deoxyribonucleic acid (DNA), ribonucleic acid (RNA), proteins and their combinations. Moreover, lncRNAs regulate orchestra of diverse functions including chromatin organization and transcriptional and post-transcriptional regulation. LncRNAs have conferred their critical role in key biological processes in human cancer including tumor initiation, proliferation, cell cycle, apoptosis, necroptosis, autophagy, and metastasis. The interwoven function of tumor-suppressor protein p53-linked lncRNAs in the ovarian cancer paradigm is of paramount importance. Several lncRNAs operate as p53 regulators or effectors and modulates a diverse array of functions either by participating in various signaling cascades or via interaction with different proteins. This review highlights the recent progress made in the identification of p53 associated lncRNAs while elucidating their molecular mechanisms behind the altered expression in ovarian cancer tumorigenesis. Moreover, the development of novel clinical and therapeutic strategies for targeting lncRNAs in human cancers harbors great promise.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.

Long noncoding RNA TUG1 facilitates cell ovarian cancer progression through targeting MiR-29b-3p/MDM2 axis

Ovarian cancer (OC) is one of the most aggressive female cancers in the world. OC trends to be diagnosed at an advanced stage with abdominal metastasis. Our study explored the biological function and underlying mechanism of lncRNA on OC cell proliferation and migration. The expression of turine up-regulated gene 1 (TUG1) in human OC tissues and cell lines was measured by qRT-PCR. OC cell proliferation, viability, migration, and invasion were measured by MTT assays, colony formation assays, and transwell assays in vitro. Furthermore, the nude mice xenograft model was established to determine the effects of TUG1 in vivo. The relationship between TUG1 and miR-29b-3p, as well as miR-29b-3p and MDM2 were identified using the luciferase reporter assays. We showed that the expression of TUG1 and MDM2 were significantly increased, but the expression of miR-29b-3p was remarkably decreased in OC tissues and cell lines. Knockdown of TUG1 strongly inhibited the ability of cell proliferation, colony formation, migration, and invasion in vitro. The relationship between TUG1 and miR-29b-3p, or miR-29b-3p and MDM2 were predicted by StarBase and miRanda online software. Besides, miR-29b-3p reversed the positive effect of TUG1 on the OC cell proliferation, migration, and invasion through inhibiting MDM2 expression and increasing p53 phosphorylation level. Moreover, knockdown of TUG1 suppressed tumor growth in vivo. Taken all together, this study shows that TUG1 plays a crucial oncogenic role and facilitates cell proliferation, migration, and invasion in OC through regulating miR-29b-3p/MDM2 axis.

Long noncoding RNA TC0101441 induces epithelial-mesenchymal transition in epithelial ovarian cancer metastasis by downregulating KiSS1

Peritoneal metastasis is a critical feature and clinical challenge in epithelial ovarian cancer (EOC). We previously identified a novel long noncoding RNA (lncRNA, TC0101441) in epithelial ovarian cancer (EOC) using microarrays. However, the impact of TC0101441 on EOC metastasis and prognosis remains unclear. TC0101441 expression in EOC tissues and its correlation with clinicopathological factors and prognosis were examined. A series of in vitro and in vivo assays were performed to elucidate the roles and mechanism of TC0101441 in EOC metastasis. We found that TC0101441 levels were elevated in EOC tissues compared with those in normal controls and significantly correlated with an advanced clinical stage and lymph node metastasis. TC0101441 was determined to be an independent prognostic predictor of overall survival (OS) and disease-free survival (DFS). Furthermore, loss-of-function assays showed that TC0101441 promoted the invasive and metastatic capacities of EOC cells both in vitro and in vivo. Mechanistically, the prometastatic effects of TC0101441 were linked to the induction of epithelial-mesenchymal transition (EMT). Importantly, KiSS1 was identified as a downstream target gene of TC0101441 and was downregulated by TC0101441 in EOC cells. After TC0101441 was silenced, the corresponding phenotypes of EOC cell invasion and EMT were reversed by the overexpression of KiSS1. Taken together, our data suggest that TC0101441 functions as a potential promigratory/invasive oncogene by promoting EMT and metastasis in EOC through downregulation of KiSS1, which may represent a novel prognostic marker and therapeutic target in EOC.

Identification of Long Noncoding RNA APOC1P1 as an Oncogene in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is one of the most common genitourinary cancers worldwide. Previous evidence shows that long noncoding RNA (LncRNA) APOC1P1 plays an important role in cancer development. However, the role of LncRNA APOC1P1 in ccRCC remains to be explored. LncRNA APOC1P1 expression in 283 ccRCC tissues and 30 normal kidney tissues was detected by quantitative real-time PCR, and its prognostic association with ccRCC was assessed by the Kaplan-Meier method and Cox proportional hazard model. Cell proliferation, apoptosis, migration, and invasion were determined in RCC cells with downregulation of LncRNA APOC1P1 expression. LncRNA APOC1P1 expression was increased in ccRCC tissues compared with normal kidney tissues (P < 0.001). Its expression was higher in the Fuhrman grade III and IV group than in the Fuhrman grade I and II group (P < 0.05) and significantly upregulated in the advanced stage group (P < 0.05). Kaplan-Meier analyses revealed that elevated LncRNA APOC1P1 expression was significantly associated with poor overall survival (P < 0.05) but may not be an independent prognostic factor. Knockdown of LncRNA APOC1P1 inhibited cell proliferation, induced apoptosis, and arrested cells at the G1/S phase (P < 0.05). Silencing of LncRNA APOC1P1 also led to decreased cell migration and invasion (P < 0.05). LncRNA APOC1P1 acts as an oncogene, plays an important role in ccRCC development, and can be considered a prognostic biomarker and therapeutic target in ccRCC patients.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

Long intergenic noncoding RNA LINC00284 knockdown reduces angiogenesis in ovarian cancer cells via up-regulation of MEST through NF-κB1

Ovarian cancer (OC) is one of the major causes of cancer-related mortality in women worldwide. Long noncoding RNAs might play a role as oncogenes or tumor suppressors. Therefore, we investigated the effect and underlying mechanisms of long intergenic noncoding RNA (LINC00) 284 on angiogenesis in OC cells. Expression of LINC00284 in OC tissues and cells was determined. Next, the interaction between LINC00284 and mesoderm-specific transcript (MEST) was evaluated. Subsequently, OC cells were transfected with overexpressed (oe)-LINC00284, silenced (si)-LINC00284, si-NF-κB1, oe-MEST, or si-MEST plasmids to investigate the underlying mechanism of LINC00284 in OC. Afterwards, the expression of matrix metalloproteinase (MMP)-2, MMP-9, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated protein x (Bax), VEGF, and CD31 was determined to assess the effect of LINC00284 on OC cell proliferation, invasion, migration angiogenesis, and apoptosis. Finally, the effect of LINC00284 on tumorigenesis was investigated in nude mice models of OC. LINC00284 was highly expressed in OC. si-LINC00284 increased expression of MEST. si-LINC00284 or si-NF-κB1 led to the reduction in cell proliferation, migration, invasion, tube formation, angiogenesis, and tumorigenic ability and promoted apoptosis in OC by down-regulating MMP-2, MMP-9, Bcl-2, VEGF, and CD31 and up-regulating Bax. These effects were all reversed following the si-MEST. In vivo experiments found the same results, confirming the aforementioned findings. Taken together, LINC00284 is involved in angiogenesis during OC development by recruiting NF-κB1 and down-regulating MEST.-Ruan, Z., Zhao, D. Long intergenic noncoding RNA LINC00284 knockdown reduces angiogenesis in ovarian cancer cells via up-regulation of MEST through NF-κB1.

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.

Wnt/β-Catenin Signaling Pathway-Related Proteins (DKK-3, β-Catenin, and c-MYC) Are Involved in Prognosis of Nasopharyngeal Carcinoma

The Wnt/β-catenin signaling pathway is one of the highly conserved signaling pathway widely reported to play essential roles in the development of various tumors and human cancers, thus serving as a potential target for anticancer therapy. However, the specific effects of the related proteins in the Wnt/β-catenin signaling pathway in nasopharyngeal carcinoma (NPC) still remain elusive. Thus, this study was performed to uncover the correlation between the Wnt/β-catenin signaling pathway-related proteins and the clinical characteristics and prognosis of NPC. NPC tissues were revealed to present high expression of β-catenin and v-myc myelocytomatosis viral oncogene homolog (c-MYC) but low expression of Dickkopf-3 (DKK-3). Immunohistochemical staining revealed that DKK-3 was positively linked to but β-catenin and c-MYC were negatively linked to differentiation, tumor-node-metastasis (TNM) stage and lymph node metastasis of patients with NPC. In addition, c-MYC was identified to be positively correlated to DKK-3 in NPC tissues. The positive expression of β-catenin and c-MYC had negative relations with and that of DKK-3 had positive relations with survival rate of patients with NPC, which was analyzed by Kaplan-Meier method. Moreover, it was shown that later TNM stage and positive expression of β-catenin were risk factors for NPC-related death. These findings provide evidence that the proteins related to the Wnt/β-catenin signaling pathway (DKK-3, β-catenin, and c-MYC) participate in the development of NPC and positive expression of DKK-3 and negative expression of β-catenin, and c-MYC can serve as essential prognostic biomarkers, shedding new light on the prognosis and treatment of NPC.

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.

LncRNAs in ovarian cancer

Ovarian cancer is one of the most common gynecologic malignancies and has a poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators of cancer development. Studies have shown that the dysregulation of lncRNAs is frequently observed in ovarian cancer and greatly contributes to malignant phenotypical changes. In this review, we provide perspectives on the involvement of lncRNAs in the proliferation, apoptosis, cell cycle, migration, invasion, metastasis and drug resistance of ovarian cancer based on recent discoveries. Then, we discuss the role of lncRNAs in predicting the prognosis of ovarian cancer. Finally, we provide insight into the potential of lncRNAs for evaluating the diagnosis and prognosis of ovarian cancer.

Long noncoding RNAs as biotargets in cisplatin-based drug resistance

Since its discovery, cisplatin has become the key drug in chemotherapy for cancers. Nevertheless, chemoresistance in cancers has become an impediment in using cisplatin for cancer treatment. The resistance toward cisplatin is multifaceted as it involves multiple cellular pathways. Ever since the knowledge of long noncoding RNAs as modulators of various molecular pathways came to light, the interest in the biological function of lncRNAs as biomarkers has increased dramatically. Numerous studies have reported the link between the dysregulation of lncRNAs and drug resistance in cancers. More importantly, several lncRNAs were found to be vital in regulating cisplatin resistance. Therefore, this review summarizes the recent efforts in linking between cisplatin resistance and different types of lncRNAs.

Novel three‑lncRNA signature predicts survival in patients with pancreatic cancer

A growing body of evidence confirms that long non-coding RNAs (lncRNAs) have an important role in biological processes by regulating gene expression at multiple levels. Dysregulated lncRNAs may be potential prognostic biomarkers or targets for the development of cancer treatments. However, the prognostic role of an lncRNA signature in pancreatic cancer has not been investigated. Pancreatic cancer lncRNA expression profiles from The Cancer Genome Atlas (TCGA) were analyzed in the current study. The prognostic value of differentially expressed lncRNAs (DElncRNAs) was evaluated via the Kaplan-Meier method. A risk score model was established based on the potential prognostic lncRNAs. The biological functions of lncRNAs were predicted by functional enrichment analysis. Then, an lncRNA-mRNA co-expression network was established and predicted the function of the lncRNAs. Seven DElncRNAs that were significantly associated with the prognosis of pancreatic cancer were identified. Patients were classified into high-risk and low-risk groups using a risk score based on a three-lncRNA signature. There was a significant difference in overall survival (OS) between the groups (median OS 1.33 vs. 3.65 years; log-rank test, P=0.0000). Cox regression analysis and ROC curves demonstrated that the three-lncRNA signature may be an effective independent prognostic biomarker in patients with pancreatic. The functional enrichment analysis showed that lncRNA AL137789.1, one component of the three-lncRNA signature, may be associated with tumor immune responses. In the present study, a novel three-lncRNA signature that was established that may be useful in predicting survival among patients with pancreatic cancer. These lncRNAs may be involved in tumor immunity and thus affect the prognosis of patients.

miR-211 sponges lncRNA MALAT1 to suppress tumor growth and progression through inhibiting PHF19 in ovarian carcinoma

Accumulating evidence has indicated that microRNAs (miRNAs) play an important role in the occurrence and progression of ovarian cancer (OC). However, the function of miRNAs implicated in OC remains unclear. This study investigated the potential role of miR-211 in OC. Gene Expression Omnibus database analysis indicated that miR-211 expression was significantly down-regulated in OC tissues compared with normal specimens. In addition, miR-211 overexpression apparently inhibited proliferation, migration, xenograft growth, and induced apoptosis in HEY-T30 and SKOV3 cells. Moreover, PHF19, a component of the polycomb group of proteins, was found to be a direct target of miR-211 based on the luciferase reporter assay and Western blot analysis. Consistently, survival analysis indicated that high PHF19 expression was associated with shorter survival time in patients with OC. Importantly, silence of PHF19 reduced proliferation, induced cell cycle arrest, promoted apoptosis, suppressed migration, and inhibited xenograft growth in SKOV3 cells. Restoration of PHF19 expression markedly reversed the inhibitory effect of miR-211 on OC. Moreover, our results indicate that the long noncoding RNA MALAT1 could sponge miR-211 as a competing endogenous RNA and potentially up-regulate PHF19 expression, thus facilitating the OC progression. These findings suggest that the MALAT1/miR-211/PHF19 axis may act as a key mediator in OC and provide new insight into the prevention of this disease.-Tao, F., Tian, X., Ruan, S., Shen, M., Zhang, Z. miR-211 sponges lncRNA MALAT1 to suppress tumor growth and progression through inhibiting PHF19 in ovarian carcinoma.

LncRNA TP73‑AS1 predicts poor prognosis and promotes cell proliferation in ovarian cancer via cell cycle and apoptosis regulation

TP73‑AS1, a critical cancer‑associated long noncoding RNA (lncRNA), has been identified in esophageal cancer and glioma. However, its biological role in ovarian cancer (OC) remains to be investigated. The aim of the present study was to investigate the role of TP73‑AS1 in human OC cell lines and clinical tumor samples to determine the function of this molecule. Reverse transcription‑quantitative polymerase chain reaction analysis was carried out to detect that TP73‑AS1 was upregulated in OC tissues and cell lines. Kaplan Meier Method was applied to study the association between overall survival of patients with OC and TP73‑AS1 expression. The results suggested that patients with high expression levels of TP73‑AS1 had lower survival compared with patients with low expression level of TP73‑AS1. MTT and colony formation assays were conducted to investigate the effects of TP73‑AS1 expression on OC cell proliferation. Flow cytometry analysis was used to analyze the effects of TP73‑AS1 expression on cell cycle progression and apoptosis. Loss‑of‑function experiments revealed that TP73‑AS1 silencing was able to suppress the growth of OC cells via modulating the cell cycle and apoptosis. The results of the present study suggest that TP73‑AS1 may be an oncogenic lncRNA that promotes the proliferation of OC cells and may therefore be an effective therapeutic target in patients with OC.

Role of lncRNAs in ovarian cancer: defining new biomarkers for therapeutic purposes

Long noncoding RNAs (lncRNAs) are a class of noncoding RNA, involved in regulation of diverse physiological and pathological processes. Ovarian cancer is the leading cause of death among all gynecological malignancies in the world and its underlying mechanism is still unclear. LncRNAs exhibit multiple biological functions in various stages of ovarian cancer development. We will discuss and summarize the new and important lncRNAs and their involvement in disease, which might represent promising therapeutic targets. Therapeutic intervention based on silencing or functional inhibition of target lncRNAs will be beneficial for ovarian cancer patients.

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.

CTD-2020K17.1, a Novel Long Non-Coding RNA, Promotes Migration, Invasion, and Proliferation of Serous Ovarian Cancer Cells In Vitro

Background

Ovarian cancer is the most lethal malignant tumor of the female reproductive system, and the metastasis is one of the major factors that contribute to the poor outcome of patients with OC. Accumulating evidence indicates that lncRNAs are expressed and play important regulatory roles in ovarian cancer.

Material/Methods

Aberrant lncRNAs in primary ovarian cancer tissues (POCTs) and paired omental metastasis tissues (OMTs) of patients with HGSOC were studied via lncRNA microarray. Real-time PCR was performed to examine CTD-2020K17.1 expression in HGSOC tissues from 38 patients, a normal ovarian surface epithelium cell line, and 4 ovarian cancer cell lines. Additionally, Transwell assays, wound healing assays, CCK-8 proliferation assays, and flow cytometry were used to explore the biological function of CTD-2020K17.1 in ovarian cancer cells. Finally, Western blot analysis was used to verify the potential target gene of CTD-2020K17.1.

Results

A novel lncRNA named CTD-2020K17.1 was identified via microarray analysis. Expression of CTD-2020K17.1 was significantly increased in OMTs and in 4 ovarian cancer cell lines compared with POCTs (P<0.05) or normal ovarian surface epithelial cell line (P<0.05). Moreover, CTD-2020K17.1 overexpression promoted migration, invasion, and proliferation of ovarian cancer cells, and CTD-2020K17.1 regulated the expression of CARD11.

Conclusions

CTD-2020K17.1 is significantly upregulated in OMTs and ovarian cancer cell lines. It can promote the migration, invasion, and proliferation of ovarian cancer cells, and CARD11 is regulated by CTD-2020K17.1.

Long non-coding RNA implicated in the invasion and metastasis of head and neck cancer: possible function and mechanisms

Head and neck cancer (HNC) ranks as the 6th most common malignancy across the world. Metastasis is a hallmark of cancer, primarily contributing to the relapse and poor prognosis of HNC. Recently, long noncoding RNAs (lncRNAs), previously considered as non-functional, are increasingly appreciated by scholars to play crucial roles in mediating HNC metastasis. LncRNAs, which are located in the nucleus and cytoplasm, mainly exert their function via epigenetic modification, transcriptional control and translational regulation. As several lncRNAs are presently demonstrated to participate in HNC metastasis, we make a summary of the functions and mechanisms regarding these lncRNAs. As shown in the literature, most lncRNAs appear to promote the metastasis of HNC. Hence, we primarily discuss the lncRNAs involved in enhancing metastasis. Additionally, more studies are needed to understand those lncRNAs without clear mechanisms. Furthermore, we introduced the upstream regulator for the aberrant expression of lncRNAs in HNC. Finally, we concisely addressed future research prospects of lncRNAs, particularly the interplay between lncRNAs and tumor immunity as well as lncRNA-targeted therapeutic techniques, and we introduced clustered regularly interspaced short palindromic repeats (CRISPR)-Display as a possibly transformative tool to study lncRNAs. Although lncRNA research is still in the initial stage, it holds great promise to be applied as a prognosticator of HNC and a therapeutic target to inhibit HNC metastasis, which could significantly enhance the outcome of HNC patients.

Taurine up-regulated gene 1 functions as a master regulator to coordinate glycolysis and metastasis in hepatocellular carcinoma

Cancer cells display altered glucose metabolism characterized by a preference for aerobic glycolysis. The aerobic glycolytic phenotype of hepatocellular carcinoma (HCC) is often correlated with tumor progression and poorer clinical outcomes. However, the issue of whether glycolytic metabolism influences metastasis in HCC remains unclear. In the current study, we showed that knockdown of taurine up-regulated gene 1 (TUG1) induces marked inhibition of cell migration, invasion, and glycolysis through suppression of microRNA (miR)-455-3p. MiR-455-3p, which is transcriptionally repressed by p21, directly targets the 3' untranslated region of adenosine monophosphate-activated protein kinase subunit beta 2 (AMPKβ2). The TUG1/miR-455-3p/AMPKβ2 axis regulates cell growth, metastasis, and glycolysis through regulation of hexokinase 2 (HK2). TUG1 is clearly associated with HK2 overexpression and unfavorable prognosis in HCC patients.

CONCLUSION

Our data collectively highlight that novel regulatory associations among TUG1, miR-455-3p, AMPKβ2, and HK2 are an important determinant of glycolytic metabolism and metastasis in HCC cells and support the potential utility of targeting TUG1/HK2 as a therapeutic strategy for HCC. (Hepatology 2018;67:188-203).

Expression of uc.189 and its clinicopathologic significance in gynecological cancers

In recent decades, emerging evidence demonstrates that ultraconserved elements (UCEs) encoding noncoding RNAs serve as regulators of gene expression. Until now, the role of uc.189 in human cancers remains undefined and the clinical significance of uc.189 in gynecological cancers remains unknown. This study was to identify the prognostic value of uc.189 expression in gynecological cancers. Tissue microarrays were constructed with 243 samples including 116 cervical squamous cell carcinomas (CSCCs), 98 endometrial adenocarcinomas (EACs), 29 ovarian cystoadenocarcinomas(OCAs), and corresponding normal tissues. In CSCC, uc.189 expression was increased in 78.5% of cases (91/116), decreased in 4.3% (5/116), and unchanged in 17.2% (20/116). In EAC its expression was increased in 74.5% (73/98), decreased in 3.1% (3/98), and unchanged in 22.4% (22/98). Expression of uc.189 was increased in 23, and unchanged/decreased in 6, of 29 cases of ovarian cystoadenocarcinomas. Univariate and multivariate Cox regression analysis demonstrated that over-expression of uc.189 predicted poor prognosis in CSCC and EAC. Thus, these findings suggested uc.189 might be an evaluating prognosis marker of gynecological tumors.

Aberrant expression of PlncRNA-1 and TUG1: potential biomarkers for gastric cancer diagnosis and clinically monitoring cancer progression

Aim: To evaluate PlncRNA-1, TUG1 and FAM83H-AS1 gene expression and their possible role as a biomarker in gastric cancer (GC) progression. Patients & methods: Long noncoding RNA expressions and clinicopathological characteristics were assessed in 70 paired GC tissues. Furthermore, corresponding data from 318 GC patients were downloaded from The Cancer Genome Atlas database. Results: Expression of PlncRNA-1 and TUG1 were significantly upregulated in GC tumoral tissues, and significantly correlated with clinicopathological characters. However, FAM83H-AS1 showed no consistently differential expression. The expression of these three long noncoding RNAs was significantly higher in The Cancer Genome Atlas tumoral tissues. Conclusion: In conclusion, PlncRNA-1 and TUG1 genes may play a critical role in GC progression and may serve as potential diagnostic biomarkers in GC patients.

TUG1, SPRY4-IT1, and HULC as valuable prognostic biomarkers of survival in cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Long noncoding RNAs (LncRNAs) are involved in the development and progression of various cancers. Accumulating evidences indicated that expression of lncRNAs was related to the prognosis of tumors.

METHODS

Here, 3 well-known lncRNAs associated with cancer were gathered to prove the potential role of lncRNAs as novel predictors of survival in human cancer. This meta-analysis collected all eligible studies about TUG1, SPRY4-IT1, and HULC and explored the relationship between lncRNAs expression and lymph node metastasis (LNM) or overall survival (OS). A comprehensive, computerized literature search was undertaken by using PubMed, EMBASE, Cochrane Library, and Web of Science (up to October 10, 2017). Strength of association between 3 lncRNAs and cancer prognosis was assessed by computing the hazard ratios (HR) with its corresponding 95% confidence interval (CI). According to the inclusion and exclusion criteria, respectively, 10, 9, and 7 studies of 3 lncRNAs were included in this meta-analysis.

RESULTS

In the current meta-analysis, it could be concluded that the expression of these 3 lncRNAs in tumor tissues is not a direct evidence of LNM. In general, there was a significant negative correlation between TUG1 levels and OS time (pooled HR 1.54, 95% CI 1.06-2.24), SPRY4-IT1 levels and OS time (pooled HR 2.12, 95% CI 1.58-2.86) and HULC levels and OS time (pooled HR 2.10, 95% CI 1.18-3.73). It could be revealed from the result that high level expression of these 3 lncRNAs might be correlated with a bad prognosis.

CONCLUSIONS

In conclusion, the current meta-analysis demonstrated that TUG1, SPRY4-IT1, and HULC might serve as a moderate predictor of survival in human cancer.

TUG1 mediates methotrexate resistance in colorectal cancer via miR-186/CPEB2 axis

Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. Methotrexate (MTX) is one of the earliest cytotoxic drugs and serves as an anti-metabolite and anti-folate chemotherapy for various types of cancer. However, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the efficacy of MTX therapies in clinics. Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years. More and more evidences have shown that lncRNAs play regulatory roles in various biological activities and disease progression including drug resistance in cancer cells. Here, we observed lncRNA TUG1 was associated to the MTX resistant in colorectal cancer cells. Firstly, quantitative analysis indicated that TUG1 was significantly increased in tumors which were resistant to MTX treatment. TUG1 knockdown re-sensitized the MTX resistance in colorectal cancer cells, which were MTX-resistant colorectal cell line. Furthermore, bioinformatics analysis showed that miR-186 could directly bind to TUG1, suggesting TUG1 might worked as a ceRNA to sponge miR-186. Extensively, our study also showed that CPEB2 was the direct target of miR-186 in colorectal cancer cells. Taken together, our study suggests that lncRNA TUG1 mediates MTX resistance in colorectal cancer via miR-186/CPEB2 axis.

Functional prediction of long non-coding RNAs in ovarian cancer-associated fibroblasts indicate a potential role in metastasis

Cancer-associated fibroblasts (CAFs) contribute to the poor prognosis of ovarian cancer. Unlike in tumour cells, DNA mutations are rare in CAFs, raising the likelihood of other mechanisms that regulate gene expression such as long non-coding RNAs (lncRNAs). We aimed to identify lncRNAs that contribute to the tumour-promoting phenotype of CAFs. RNA expression from 67 ovarian CAF samples and 10 normal ovarian fibroblast (NOF) samples were analysed to identify differentially expressed lncRNAs and a functional network was constructed to predict those CAF-specific lncRNAs involved in metastasis. Of the 1,970 lncRNAs available for analysis on the gene expression array used, 39 unique lncRNAs were identified as differentially expressed in CAFs versus NOFs. The predictive power of differentially expressed lncRNAs in distinguishing CAFs from NOFs were assessed using multiple multivariate models. Interrogation of known transcription factor-lncRNA interactions, transcription factor-gene interactions and construction of a context-specific interaction network identified multiple lncRNAs predicted to play a role in metastasis. We have identified novel lncRNAs in ovarian cancer that are differentially expressed in CAFs compared to NOFs and are predicted to contribute to the metastasis-promoting phenotype of CAFs.